Polyolefin Foams

Rapra Review Reports

Report 167

ISSN: 0889-3144

Polyolefin Foams

N,J, Mills

Volume 14, Number 11, 2004

Rapra Review Reports Expert overviews covering the science and technology of rubber and plastics

RAPRA REVIEW REPORTS A Rapra Review Report comprises three sections, as follows: 1. A commissioned expert review, discussing a key topic of current interest, and referring to the References and Abstracts section. Reference numbers in brackets refer to item numbers from the References and Abstracts section. Where it has been necessary for completeness to cite sources outside the scope of the Rapra Abstracts database, these are listed at the end of the review, and cited in the text as a.1, a.2, etc. 2. A comprehensive References and Abstracts section, resulting from a search of the Rapra Polymer Library database. The format of the abstracts is outlined in the sample record below. 3. An index to the References and Abstracts section, derived from the indexing terms which are added to the abstracts records on the database to aid retrieval.

Source of original article Title

Item 1 Macromolecules

33, No.6, 21st March 2000, p.2171-83 EFFECT OF THERMAL HISTORY ON THE RHEOLOGICAL BEHAVIOR OF THERMOPLASTIC POLYURETHANES Pil Joong Yoon; Chang Dae Han Akron,University The effect of thermal history on the rheological behaviour of ester- and ether-based commercial thermoplastic PUs (Estane 5701, 5707 and 5714 from B.F.Goodrich) was investigated. It was found that the injection moulding temp. used for specimen preparation had a marked effect on the variations of dynamic storage and loss moduli of specimens with time observed during isothermal annealing. Analysis of FTIR spectra indicated that variations in hydrogen bonding with time during isothermal annealing very much resembled variations of dynamic storage modulus with time during isothermal annealing. Isochronal dynamic temp. sweep experiments indicated that the thermoplastic PUs exhibited a hysteresis effect in the heating and cooling processes. It was concluded that the microphase separation transition or order-disorder transition in thermoplastic PUs could not be determined from the isochronal dynamic temp. sweep experiment. The plots of log dynamic storage modulus versus log loss modulus varied with temp. over the entire range of temps. (110-190C) investigated. 57 refs.

Location

GOODRICH B.F. USA

Authors and affiliation

Abstract

Companies or organisations mentioned

Accession no.771897

DOCUMENT DELIVERY SERVICE Almost all of the documents which are listed in the References and Abstracts section are available in full text form, as photocopies or pdf files from Rapra Technology Ltd’s Document Delivery Service. Documents can be delivered by a variety of methods, including email, post or fax. Customers may pay for individual copies at the time of ordering by credit card or alternatively open up a deposit account. See the back of this report for further information. Please contact the Document Delivery Department for availability, current prices and delivery methods. Document Delivery Department Rapra Technology Limited, Shawbury, Shrewsbury, Shropshire SY4 4NR, United Kingdom Telephone: +44 (0)1939 250383 Fax: +44 (0)1939 251118 Email: [email protected]

RAPRA REVIEW REPORTS VOLUME 14 Series Editor Dr. S. Humphreys, Rapra Technology Limited Rapra Review Reports comprise a unique source of polymer-related information with useful overviews accompanied by abstracts from hundreds of relevant documents. A Rapra Review Report is an excellent starting point to improve subject knowledge in key areas. Subscribers to this series build up a bank of information over each year, forming a small library at a very reasonable price. This series would be an asset to corporate libraries, academic institutions and research associations with an interest in polymer science. Twelve reports are published in each volume and these can be purchased individually or on a subscription basis. Format: Soft-backed, 297 x 210 mm, ISSN: 0889-3144 Order individual published Rapra Review Reports (see the following pages for a list of available titles), or purchase a subscription to Volume 14 (12 issues).

ORDER FORM Title of Publication

Price £/$/€

I would like to order the following Rapra Review Report(s) at £80 / US$128 / €128 each Report Number(s) ................................................................................................ (please state quantity if more than one) Please add postage at the following rates: UK £5 total, Overseas £7 / US$11 / €10 per item Subtotal: I would like to order ................ subscription(s) to Volume 14 of the Rapra Review Report Series at £650 / US$975 / €1105 each Please add postage at the following rates: UK £35 total, Overseas £65 / US$110 / €110 per subscription All prices are subject to change and orders will be charged at the price indicated on www.polymer-books.com on the date of processing

❑ Remittance enclosed (Please make cheques payable to Rapra Technology Ltd. in

£ Sterling drawn on a UK bank or in US$ / Euros - Unesco coupons are also accepted.)

❑ Please invoice my company ❑ Please charge my credit card American Express/Visa/Mastercard (delete as appropriate) For credit card orders we require all of the following details to be completed prior to processing your order.

Total Order Value:

IMPORTANT - Value Added Tax (VAT) The above prices do not include VAT. Customers in EU member countries may be liable to pay VAT if their Registration Number is not supplied. Please enter your EU Registration Number (VAT - BTW - IVA - TVA - MWST - MOMS - FPA) below: VAT Number:

Card Number: Full Name: ________________________________________________ Please enter the cards security code below, or provide us with your telephone number or email address. (Visa/Mastercard - the last 3 digits from the number on the signature strip on the back of the card, Amex - 4 digit code from the front of the card.)

Company: _________________________________________________

3 or 4 Digit Security Code: ___________

Job Function: ______________________________________________

Signature: ______________________ Exp. date: _________________ Issuing Bank: ______________________________________________

Delivery Address (if different from Cardholder's Address): _________ _________________________________________________________

Cardholder's Name (as on card): _______________________________ _________________________________________________________ Cardholder's Address: _______________________________________ _________________________________________________________ _________________________________________________________ Postcode: ______________________ Country: __________________ Telephone: _____________________ Fax: ______________________ Company PO#: _____________________________________________

Please Return to:

Publications Sales, Rapra Technology Limited Shawbury, Shrewsbury, Shropshire SY4 4NR, United Kingdom

Postcode: ______________________ Country: __________________ Telephone: _____________________ Fax: ______________________ If you would like to receive regular electronic updates informing you of new titles and offers please enter your E-mail address below. E-mail: ___________________________________________________ Tel. +44 (0)1939 250383 Fax: +44 (0)1939 251118 E-mail: [email protected]

www.rapra.net

Previous Titles Still Available Volume 1

Volume 4

Report 3

Advanced Composites, D.K. Thomas, RAE, Farnborough.

Report 37

Report 4

Liquid Crystal Polymers, M.K. Cox, ICI, Wilton.

Polymers in Aerospace Applications, W.W. Wright, University of Surrey.

Report 5

CAD/CAM in the Polymer Industry, N.W. Sandland and M.J. Sebborn, Cambridge Applied Technology.

Report 39

Polymers in Chemically Resistant Applications, D. Cattell, Cattell Consultancy Services.

Report 8

Engineering Thermoplastics, I.T. Barrie, Consultant.

Report 41

Failure of Plastics, S. Turner, Queen Mary College.

Report 11

Communications Applications of Polymers, R. Spratling, British Telecom.

Report 42

Polycarbonates, R. Pakull, U. Grigo, D. Freitag, Bayer AG.

Report 12

Process Control in the Plastics Industry, R.F. Evans, Engelmann & Buckham Ancillaries.

Report 43

Polymeric Materials from Renewable Resources, J.M. Methven, UMIST.

Report 44

Flammability and Flame Retardants in Plastics, J. Green, FMC Corp.

Volume 2 Report 13

Injection Moulding of Engineering Thermoplastics, A.F. Whelan, London School of Polymer Technology.

Report 45

Composites - Tooling and Component Processing, N.G. Brain, Tooltex.

Report 14

Polymers and Their Uses in the Sports and Leisure Industries, A.L. Cox and R.P. Brown, Rapra Technology Ltd.

Report 46

Quality Today in Polymer Processing, S.H. Coulson, J.A. Cousans, Exxon Chemical International Marketing.

Report 47

Report 15

Polyurethane, Materials, Processing and Applications, G. Woods, Consultant.

Chemical Analysis of Polymers, G. Lawson, Leicester Polytechnic.

Report 16

Polyetheretherketone, D.J. Kemmish, ICI, Wilton.

Report 17

Extrusion, G.M. Gale, Rapra Technology Ltd.

Report 49

Report 18

Agricultural and Horticultural Applications of Polymers, J.C. Garnaud, International Committee for Plastics in Agriculture.

Blends and Alloys of Engineering Thermoplastics, H.T. van de Grampel, General Electric Plastics BV.

Report 50

Report 19

Recycling and Disposal of Plastics Packaging, R.C. Fox, Plas/Tech Ltd.

Automotive Applications of Polymers II, A.N.A. Elliott, Consultant.

Report 51

Report 20

Pultrusion, L. Hollaway, University of Surrey.

Biomedical Applications of Polymers, C.G. Gebelein, Youngstown State University / Florida Atlantic University.

Report 21

Materials Handling in the Polymer Industry, H. Hardy, Chronos Richardson Ltd.

Report 52

Polymer Supported Chemical Reactions, P. Hodge, University of Manchester.

Report 22

Electronics Applications of Polymers, M.T.Goosey, Plessey Research (Caswell) Ltd.

Report 53

Weathering of Polymers, S.M. Halliwell, Building Research Establishment.

Report 23

Offshore Applications of Polymers, J.W.Brockbank, Avon Industrial Polymers Ltd.

Report 54

Health and Safety in the Rubber Industry, A.R. Nutt, Arnold Nutt & Co. and J. Wade.

Report 24

Recent Developments in Materials for Food Packaging, R.A. Roberts, Pira Packaging Division.

Report 55

Computer Modelling of Polymer Processing, E. Andreassen, Å. Larsen and E.L. Hinrichsen, Senter for Industriforskning, Norway.

Volume 3

Report 56

Plastics in High Temperature Applications, J. Maxwell, Consultant.

Report 25

Report 57

Joining of Plastics, K.W. Allen, City University.

Report 58

Physical Testing of Rubber, R.P. Brown, Rapra Technology Ltd.

Report 59

Polyimides - Materials, Processing and Applications, A.J. Kirby, Du Pont (U.K.) Ltd. Physical Testing of Thermoplastics, S.W. Hawley, Rapra Technology Ltd.

Foams and Blowing Agents, J.M. Methven, Cellcom Technology Associates.

Volume 5

Report 26

Polymers and Structural Composites in Civil Engineering, L. Hollaway, University of Surrey.

Report 27

Injection Moulding of Rubber, M.A. Wheelans, Consultant.

Report 28

Adhesives for Structural and Engineering Applications, C. O’Reilly, Loctite (Ireland) Ltd.

Report 60

Report 29

Polymers in Marine Applications, C.F.Britton, Corrosion Monitoring Consultancy.

Volume 6

Report 30

Non-destructive Testing of Polymers, W.N. Reynolds, National NDT Centre, Harwell.

Report 61

Food Contact Polymeric Materials, J.A. Sidwell, Rapra Technology Ltd.

Report 31

Silicone Rubbers, B.R. Trego and H.W.Winnan, Dow Corning Ltd.

Report 62

Coextrusion, D. Djordjevic, Klöckner ER-WE-PA GmbH.

Report 63

Conductive Polymers II, R.H. Friend, University of Cambridge, Cavendish Laboratory.

Report 64

Designing with Plastics, P.R. Lewis, The Open University. Decorating and Coating of Plastics, P.J. Robinson, International Automotive Design.

Report 32

Fluoroelastomers - Properties and Applications, D. Cook and M. Lynn, 3M United Kingdom Plc and 3M Belgium SA.

Report 33

Polyamides, R.S. Williams and T. Daniels, T & N Technology Ltd. and BIP Chemicals Ltd.

Report 65

Report 34

Extrusion of Rubber, J.G.A. Lovegrove, Nova Petrochemicals Inc.

Report 66

Report 35

Polymers in Household Electrical Goods, D.Alvey, Hotpoint Ltd.

Reinforced Thermoplastics - Composition, Processing and Applications, P.G. Kelleher, New Jersey Polymer Extension Center at Stevens Institute of Technology.

Report 67

Report 36

Developments in Additives to Meet Health and Environmental Concerns, M.J. Forrest, Rapra Technology Ltd.

Plastics in Thermal and Acoustic Building Insulation, V.L. Kefford, MRM Engineering Consultancy.

Report 68

Cure Assessment by Physical and Chemical Techniques, B.G. Willoughby, Rapra Technology Ltd.

Report 69

Toxicity of Plastics and Rubber in Fire, P.J. Fardell, Building Research Establishment, Fire Research Station.

Report 70

Acrylonitrile-Butadiene-Styrene Polymers, M.E. Adams, D.J. Buckley, R.E. Colborn, W.P. England and D.N. Schissel, General Electric Corporate Research and Development Center.

Report 71

Rotational Moulding, R.J. Crawford, The Queen’s University of Belfast.

Report 72

Advances in Injection Moulding, C.A. Maier, Econology Ltd.

Report 94

Compressive Behaviour of Composites, C. Soutis, Imperial College of Science, Technology and Medicine.

Report 95

Thermal Analysis of Polymers, M. P. Sepe, Dickten & Masch Manufacturing Co.

Report 96

Polymeric Seals and Sealing Technology, J.A. Hickman, St Clair (Polymers) Ltd.

Volume 9 Report 97

Rubber Compounding Ingredients - Need, Theory and Innovation, Part II: Processing, Bonding, Fire Retardants, C. Hepburn, University of Ulster.

Report 98

Advances in Biodegradable Polymers, G.F. Moore & S.M. Saunders, Rapra Technology Ltd.

Report 99

Recycling of Rubber, H.J. Manuel and W. Dierkes, Vredestein Rubber Recycling B.V.

Volume 7 Report 73

Reactive Processing of Polymers, M.W.R. Brown, P.D. Coates and A.F. Johnson, IRC in Polymer Science and Technology, University of Bradford.

Report 74

Speciality Rubbers, J.A. Brydson.

Report 75

Plastics and the Environment, I. Boustead, Boustead Consulting Ltd.

Report 100 Photoinitiated Polymerisation - Theory and Applications, J.P. Fouassier, Ecole Nationale Supérieure de Chimie, Mulhouse.

Report 76

Polymeric Precursors for Ceramic Materials, R.C.P. Cubbon.

Report 101 Solvent-Free Adhesives, T.E. Rolando, H.B. Fuller Company.

Report 77

Advances in Tyre Mechanics, R.A. Ridha, M. Theves, Goodyear Technical Center.

Report 102 Plastics in Pressure Pipes, T. Stafford, Rapra Technology Ltd.

Report 78

PVC - Compounds, Processing and Applications, J.Leadbitter, J.A. Day, J.L. Ryan, Hydro Polymers Ltd.

Report 103

Report 79

Rubber Compounding Ingredients - Need, Theory and Innovation, Part I: Vulcanising Systems, Antidegradants and Particulate Fillers for General Purpose Rubbers, C. Hepburn, University of Ulster.

Report 80

Anti-Corrosion Polymers: PEEK, PEKK and Other Polyaryls, G. Pritchard, Kingston University.

Report 81

Thermoplastic Elastomers - Properties and Applications, J.A. Brydson.

Report 82

Advances in Blow Moulding Process Optimization, Andres Garcia-Rejon,Industrial Materials Institute, National Research Council Canada.

Report 83

Molecular Weight Characterisation of Synthetic Polymers, S.R. Holding and E. Meehan, Rapra Technology Ltd. and Polymer Laboratories Ltd.

Report 84

Rheology and its Role in Plastics Processing, P. Prentice, The Nottingham Trent University.

Gas Assisted Moulding, T.C. Pearson, Gas Injection Ltd.

Report 104 Plastics Profile Extrusion, R.J. Kent, Tangram Technology Ltd. Report 105 Rubber Extrusion Theory and Development, B.G. Crowther. Report 106 Properties and Applications of Elastomeric Polysulfides, T.C.P. Lee, Oxford Brookes University. Report 107 High Performance Polymer Fibres, P.R. Lewis, The Open University. Report 108 Chemical Characterisation of Polyurethanes, M.J. Forrest, Rapra Technology Ltd.

Volume 10 Report 109 Rubber Injection Moulding - A Practical Guide, J.A. Lindsay. Report 110 Long-Term and Accelerated Ageing Tests on Rubbers, R.P. Brown, M.J. Forrest and G. Soulagnet, Rapra Technology Ltd.

Volume 8

Report 111

Polymer Product Failure, P.R. Lewis, The Open University.

Report 85

Ring Opening Polymerisation, N. Spassky, Université Pierre et Marie Curie.

Report 112 Polystyrene - Synthesis, Production and Applications, J.R. Wünsch, BASF AG.

Report 86

High Performance Engineering Plastics, D.J. Kemmish, Victrex Ltd.

Report 113 Rubber-Modified Thermoplastics, H. Keskkula, University of Texas at Austin.

Report 87

Rubber to Metal Bonding, B.G. Crowther, Rapra Technology Ltd.

Report 114 Developments in Polyacetylene - Nanopolyacetylene, V.M. Kobryanskii, Russian Academy of Sciences.

Report 88

Plasticisers - Selection, Applications and Implications, A.S. Wilson.

Report 115 Metallocene-Catalysed Polymerisation, W. Kaminsky, University of Hamburg.

Report 89

Polymer Membranes - Materials, Structures and Separation Performance, T. deV. Naylor, The Smart Chemical Company.

Report 116 Compounding in Co-rotating Twin-Screw Extruders, Y. Wang, Tunghai University.

Report 90

Rubber Mixing, P.R. Wood.

Report 117 Rapid Prototyping, Tooling and Manufacturing, R.J.M. Hague and P.E. Reeves, Edward Mackenzie Consulting.

Report 91

Recent Developments in Epoxy Resins, I. Hamerton, University of Surrey.

Report 118 Liquid Crystal Polymers - Synthesis, Properties and Applications, D. Coates, CRL Ltd.

Report 92

Continuous Vulcanisation of Elastomer Profiles, A. Hill, Meteor Gummiwerke.

Report 119 Rubbers in Contact with Food, M.J. Forrest and J.A. Sidwell, Rapra Technology Ltd.

Report 93

Advances in Thermoforming, J.L. Throne, Sherwood Technologies Inc.

Report 120 Electronics Applications of Polymers II, M.T. Goosey, Shipley Ronal.

Volume 11 Report 121 Polyamides as Engineering Thermoplastic Materials, I.B. Page, BIP Ltd. Report 122 Flexible Packaging - Adhesives, Coatings and Processes, T.E. Rolando, H.B. Fuller Company. Report 123 Polymer Blends, L.A. Utracki, National Research Council Canada. Report 124 Sorting of Waste Plastics for Recycling, R.D. Pascoe, University of Exeter.

Report 147 Rubber Product Failure, Roger P. Brown Report 148 Plastics Waste – Feedstock Recycling, Chemical Recycling and Incineration, A. Tukker, TNO Report 149 Analysis of Plastics, Martin J. Forrest, Rapra Technology Ltd. Report 150 Mould Sticking, Fouling and Cleaning, D.E. Packham, Materials Research Centre, University of Bath Report 151 Rigid Plastics Packaging - Materials, Processes and Applications, F. Hannay, Nampak Group Research & Development

Report 125 Structural Studies of Polymers by Solution NMR, H.N. Cheng, Hercules Incorporated.

Report 152 Natural and Wood Fibre Reinforcement in Polymers, A.K. Bledzki, V.E. Sperber and O. Faruk, University of Kassel

Report 126 Composites for Automotive Applications, C.D. Rudd, University of Nottingham.

Report 153 Polymers in Telecommunication Devices, G.H. Cross, University of Durham

Report 127 Polymers in Medical Applications, B.J. Lambert and F.-W. Tang, Guidant Corp., and W.J. Rogers, Consultant.

Report 154 Polymers in Building and Construction, S.M. Halliwell, BRE

Report 128 Solid State NMR of Polymers, P.A. Mirau, Lucent Technologies. Report 129 Failure of Polymer Products Due to Photo-oxidation, D.C. Wright. Report 130 Failure of Polymer Products Due to Chemical Attack, D.C. Wright. Report 131 Failure of Polymer Products Due to Thermo-oxidation, D.C. Wright. Report 132 Stabilisers for Polyolefins, C. Kröhnke and F. Werner, Clariant Huningue SA.

Volume 12 Report 133 Advances in Automation for Plastics Injection Moulding, J. Mallon, Yushin Inc.

Report 155 Styrenic Copolymers, Andreas Chrisochoou and Daniel Dufour, Bayer AG Report 156 Life Cycle Assessment and Environmental Impact of Polymeric Products, T.J. O’Neill, Polymeron Consultancy Network

Volume 14 Report 157 Developments in Colorants for Plastics, Ian N. Christensen Report 158 Geosynthetics, David I. Cook Report 159 Biopolymers, R.M. Johnson, L.Y. Mwaikambo and N. Tucker, Warwick Manufacturing Group Report 160 Emulsion Polymerisation and Applications of Latex, Christopher D. Anderson and Eric S. Daniels, Emulsion Polymers Institute Report 161 Emissions from Plastics, C. Henneuse-Boxus and T. Pacary, Certech

Report 134 Infrared and Raman Spectroscopy of Polymers, J.L. Koenig, Case Western Reserve University.

Report 162 Analysis of Thermoset Materials, Precursors and Products, Martin J. Forrest, Rapra Technology Ltd

Report 135 Polymers in Sport and Leisure, R.P. Brown.

Report 163 Polymer/Layered Silicate Nanocomposites, Masami Okamoto, Toyota Technological Institute

Report 136 Radiation Curing, R.S. Davidson, DavRad Services. Report 137 Silicone Elastomers, P. Jerschow, Wacker-Chemie GmbH.

Report 164 Cure Monitoring for Composites and Adhesives, David R. Mulligan, NPL

Report 138 Health and Safety in the Rubber Industry, N. Chaiear, Khon Kaen University.

Report 165 Polymer Enhancement of Technical Textiles, Roy W. Buckley

Report 139 Rubber Analysis - Polymers, Compounds and Products, M.J. Forrest, Rapra Technology Ltd. Report 140 Tyre Compounding for Improved Performance, M.S. Evans, Kumho European Technical Centre. Report 141 Particulate Fillers for Polymers, Professor R.N. Rothon, Rothon Consultants and Manchester Metropolitan University. Report 142 Blowing Agents for Polyurethane Foams, S.N. Singh, Huntsman Polyurethanes. Report 143 Adhesion and Bonding to Polyolefins, D.M. Brewis and I. Mathieson, Institute of Surface Science & Technology, Loughborough University. Report 144 Rubber Curing Systems, R.N. Datta, Flexsys BV.

Volume 13 Report 145 Multi-Material Injection Moulding, V. Goodship and J.C. Love, The University of Warwick. Report 146 In-Mould Decoration of Plastics, J.C. Love and V. Goodship, The University of Warwick

Report 166 Developments in Thermoplastic Elastomers, K.E. Kear

Polyolefin Foams

N.J. Mills (Metallurgy and Materials, University of Birmingham)

ISBN 1-85957-434-3

Polyolefin Foams

Contents

1

Introduction .............................................................................................................................................. 3

2

Polymers ................................................................................................................................................... 4 2.1

3

4

2.2

Polyethylenes .................................................................................................................................. 4 2.1.1 Blends ................................................................................................................................. 4 Ethylene Styrene ‘Interpolymers’ ................................................................................................... 4

2.3

EPDM ............................................................................................................................................. 5

2.4

Polypropylenes ................................................................................................................................ 6

Processing ................................................................................................................................................. 6 3.1

Melt Rheology Suitable for Foaming ............................................................................................. 6

3.2

3.3

Foam Expansion ............................................................................................................................. 7 3.2.1 Control of Cell Size and Cell Stability ............................................................................... 7 3.2.2 Control of Density .............................................................................................................. 8 Post-Extrusion Shrinkage ............................................................................................................... 9

3.4

Rotomoulding ............................................................................................................................... 10

3.5

Microcellular Foams ..................................................................................................................... 10

3.6

Oriented PP Foams – Strandfoam ..................................................................................................11

Mechanical Properties ........................................................................................................................... 12 4.1

Initial Response in Compression .................................................................................................. 12

4.2

Bulk Modulus ............................................................................................................................... 13

4.3

Compressive Collapse .................................................................................................................. 13

4.4

High Strain Compressive Response ............................................................................................. 13

4.5

Heat Transfer from Gas to Polymer During High Strain Compression ....................................... 14

4.6

Creep Response and Air Loss from Cells ..................................................................................... 15

4.7

Recovery After Creep ................................................................................................................... 17

4.8

Fatigue ........................................................................................................................................... 18

4.9

Cushion Curves for Impact Response .......................................................................................... 18

4.10 Impact Response in Shear or Shear Plus Compression ................................................................ 18 4.11 Recovery After Impact .................................................................................................................. 19 4.12 Multiple Impacts ........................................................................................................................... 19 5

Thermal Properties ................................................................................................................................ 19 5.1

Dynamic Mechanical Thermal Analysis (DMTA) ....................................................................... 19

5.2

Thermal Expansion ....................................................................................................................... 20

1

Polyolefin Foams

5.3 6

7

Thermal Conductivity ................................................................................................................... 20

Applications ............................................................................................................................................ 21 6.1

Packaging Against Impact Damage .............................................................................................. 21

6.2

EVA in Running Shoe Midsoles ................................................................................................... 21

6.3

Body Armour ................................................................................................................................ 22

6.4

Helmets ......................................................................................................................................... 23

6.5

Soccer Shin Protectors .................................................................................................................. 23

6.6

Automotive ................................................................................................................................... 23

Market Growth ...................................................................................................................................... 24

Acknowledgements ........................................................................................................................................ 24 Additional References ................................................................................................................................... 24 Acronyms and Abbreviations ....................................................................................................................... 26 Abstracts from the Polymer Library Database .......................................................................................... 27 Subject Index ................................................................................................................................................119 Company Index............................................................................................................................................ 135

The views and opinions expressed by authors in Rapra Review Reports do not necessarily reflect those of Rapra Technology Limited or the editor. The series is published on the basis that no responsibility or liability of any nature shall attach to Rapra Technology Limited arising out of or in connection with any utilisation in any form of any material contained therein.

2

Polyolefin Foams

solid foam. He emphasised that a range of new foams could be made using random or graft PE copolymers. Extruded foams could be made with fine cells in sheet and tube form, and as could insulation on wire. He showed the effects of gel content on the foam density. Part II describes the shape of the compressive stress strain graph, with the initial elastic region, plateau region, and an upturn at high strains. To explain the graph, he used Skochdopole’s (a.5) model (Figure 2) of the cell air and the polymer structure acting in parallel. He presented graphs showing how the foam flexural modulus depends on a power of the foam density. Both Figure 2 and the power law variation were taken up by Gibson and Ashby 20 years later. Part III emphasises the orientation of the cell faces, and notes that faces shrivel on a hot stage microscope.

1 Introduction Olefins or ‘alkenes’ are defined as unsaturated aliphatic hydrocarbons. Ethylene and propylene are the main monomers for polyolefin foams, but dienes such as polyisoprene should also be included. The copolymers of ethylene and propylene (PP) will be included, but not polyvinyl chloride (PVC), which is usually treated as a separate polymer class. The majority of these foams have densities <100 kg m-3, and their microstructure consists of closed, polygonal cells with thin faces (Figure 1a). The review will not consider structural foam injection mouldings of PP, which have solid skins and cores of density in the range 400 to 700 kg m-3, and have distinct production methods and properties (456). The microstructure of these foams consists of isolated gas bubbles, often elongated by the flow of thermoplastic. However, elastomeric and microcellular foams of relative density in the range 0.3 to 0.5, which also have isolated spherical bubbles (Figure 1b), will be included. The relative density of a foam is defined as the foam density divided by the polymer density. It is the inverse of the ‘expansion ratio’. Benning’s three papers in the late 1960s (a.2-a.4) reviewed the development of closed-cell polyolefin foams, and their mechanical properties. Some of his predictions on materials development turned out to be true. In Part I he explains that non-crosslinked polyethylene (PE) foams have inferior creep properties to crosslinked foams; this appeared to be the tensile creep of the melt, rather than compressive creep of the

(a)

Figure 2 Model (redrawn from a.5) of the cell air and the polymer structure acting in parallel in a compressed closed-cell foam

(b)

Figure 1 Foam microstructures: (a) SEM of closed, polygonal cells in LDPE foam of density 18 kg m-3 after 60 hours in vacuum (a.1); (b) optical micrograph of isolated spherical bubbles in Astrene foam of density 790 kg m-3, width of photo 3.5 mm

3

Polyolefin Foams

Much of the research in the last decade confirms and extends this research. The papers provide detailed technology or science, rather than reviewing the bigger picture. This review will concentrate on 12 main areas, allowing space for detailed discussion. It emphasises mechanical and physical properties and modelling, areas which have not been recently reviewed. Blowing agent chemistry and processes are reviewed in (303, a.6). The review first considers processing, which highlights the polymer properties necessary for successful foam production. The polymer section then explains the molecular structures that produce these properties, before considering novel polymers used for foams. The properties sections emphasise mechanical and thermal properties, while the applications section shows how these properties are used.

can be achieved in a single reactor by combining two metallocene catalysts. Metallocene polyethylenes crystallise differently to Ziegler-Natta polyethylene; due to the more uniform microstructure and narrower molecular weight distribution, the crystalline lamellae are uniformly thin, and have slightly lower melting points than Ziegler PE. The different crystalline morphology affects the mechanical properties. In the USA, 3 firms (Dow, ExxonMobil and Nova Chemical) use the metallocene catalysis route for production of PE. EVA copolymers are made with a range of VA content, usually between 15 and 22%, which means that the overall crystallinity is about 20%, lower than the 40 to 50% for LDPE. The crystalline regions in EVA have a melting temperature of about 70 °C, compared with about 110 °C in metallocene LDPE.

2.1.1 Blends

2 Polymers

2.1 Polyethylenes The traditional division was into HDPE and LDPE polyethylenes, made by low and high pressure processes, respectively. Low density polyethylene, made by the high pressure ICI method, has a wide molecular weight distribution and contains long chain branches; the latter give the melt a high elasticity, hence a high tensile strength. Linear low density polyethylene can be produced by using Ziegler Natta catalyst systems at low pressures; it has a narrower molecular weight distribution than LDPE. The more recent metallocene single site catalysts (a.7) allow the production of ethylene copolymers with larger amounts of octene than with Ziegler catalysts. This allows densities lower than that of conventional LDPE (910 kg m-3) to be made. LDPE made using metallocene catalysts has a narrow molecular weight distribution (MW/MN = 2), so may have a much lower level of melt elasticity. Eaves (92) distinguished between polyolefin plastomers (POP) with density >910 kg m -3 and polyolefin (POE) elastomers with densities <910 kg m-3. The density of a polyethylene at 20 °C is a linear function of the crystallinity, with limiting values of 854 kg m-3 for zero crystallinity and 1000 kg m-3 for 100% crystallinity. The polyolefin elastomer foams compete with EVA copolymer foams. Metallocene chemistry also allows the production of copolymers with a larger comonomer content in the high molecular weight part than in the low molecular weight part; this

4

The effect of blending LDPE with EVA or a styreneisoprene block copolymer was investigated (178). The properties (thermal expansion coefficient, Young’s modulus, thermal conductivity) of the foamed blends usually lie between the limits of the foamed constituents, although the relationship between property and blend content is not always linear. The reasons must lie in the microstructure; most polymer pairs are immiscible, but some such as PS/polyphenylene oxide (PPO) are miscible. For the immiscible blends, the majority phase tends to be continuous, but the form of the minor phase can vary. Blends of EVA and metallocene catalysed ethylene-octene copolymer have different morphologies depending on the EVA content (5). With 25% EVA, the EVA phase appears as fine spherical inclusions in the LDPE matrix. The results of these experiments on polymer films will apply to foams made from the same polymers. Blends of LDPE with ethylene styrene interpolymers (ESI, see Section 3.2) also have a complex microstructure. The semi-crystalline LDPE is immiscible with the amorphous ESI, which has a glass transition temperature (T g ) just above room temperature. Consequently there are rigid crystalline regions and rubbery amorphous LDPE, mixed on a 0.1 μm scale, together with regions of leathery ESI on a 5 to 10 μm scale (71).

2.2 Ethylene Styrene ‘Interpolymers’ Ethylene styrene ‘interpolymers’ (ESI) were produced by Dow with the use of single site metallocene

Polyolefin Foams

catalysts. The term ‘interpolymer’ implies a random copolymer. They differ markedly from the other polyolefins in that they can be amorphous and glassy at room temperature. They are relatively expensive; consequently there has been interest in blending these materials with cheaper LDPE or EVA. Dow originally produced these materials, and there was a joint venture Select to produce ESI foams. The polymer was sold to the Rogers Corporation, and production subsequently ceased. The ESI domains in ESI/LDPE blends are 0.1 to 2.8 μm in length (71). As the ESI (S series with 70% styrene) used was amorphous, the use of ESI reduced the overall crystallinity of the blend. However, with 25% ESI, the compressive stress at 25% compression of the foam is unchanged. For ESI, the processing window is wider, and the cell structure is slightly finer than for the equivalent LDPE foam. The styrene content affects the crystallinity of ESI (131); for >50% styrene the copolymers are amorphous. As the styrene content is increased from 50 to 70% styrene the Tg increases from –15 °C to 20 °C. Low density foams were made (8) from a blend of 50% of various ESI polymers, 33% of EVA and 17% of azodicarbonamide blowing agent. Thermal analysis showed that the blends, with an ESI having approximately 70% styrene, had a Tg in the range 22 to 30 °C. Dynamic mechanical thermal analysis (DMTA) traces (see Section 5.1) show that these blends

soften over the temperature range 20 to 40 °C, so have high damping in this range. The relative densities of these foams were approximately 0.04; tensile tests show that at 20 °C they have yield stresses in the range 1.5 to 2.5 MPa. Although these values are high, at a slightly higher temperature the foam will be much softer. If up to 40% of ESI is blended with LDPE then foamed, the foam properties are closer to those of LDPE foams. Ankrah and co-workers (33) showed that the ESI/LDPE blends have slightly lower initial compressive yield strengths than the LDPE alone, allowing for the density of the foam. The temperature dependence of the yield stress is similar to that of LDPE foam (Figure 3). Although the yield stress is higher than EVA foam of the same density, the compression set values are lower. The ESI/LDPE foams have improved impact properties, compared with EVA foams of similar density. Analysis of creep tests shows that air diffuses from the cells at a similar rate to EVA foams of a greater density.

2.3 EPDM The majority of these systems are crosslinked, so are thermosets. The term thermoplastic vulcanisates (TPV) is also used (a.8). Copolymers are made from ethylene, propylene and a small fraction of unsaturated diene, so allowing the crosslinking of the foam. For applications such as mouse mats, the foam density is

Figure 3 Variation of initial compressive yield stress of ESI/LDPE foams with temperature, compared with an EVA and a LDPE foam, all corrected to a density of 47 kg m-3 (33)

5

Polyolefin Foams

quite high, and it is loaded with carbon black to prevent static build up. The optimisation of EPDM processing is complex (168, 169), since the blowing agent decomposition and the crosslinking reactions may influence each other. High-activity zinc oxide is used to accelerate the crosslinking reaction, necessary for the production of weatherstrips.

2.4 Polypropylenes Two technologies exist for making high melt strength PP. It appears that the majority of such polymers have undergone post-polymerisation treatments in which branches are grafted to the main chain. It is also possible to make branched PP directly in the polymerisation reactor. The Dow PP ‘Inspire’ (72) is based on the ‘Insite’ polymerisation technology, but no details are given on either the catalysts or the resulting molecular architecture. Degradation is a possibility for PE and PP foam, since these materials have a high surface area and PP in particular is easily oxidised. The chemical resistance of polyolefin foams should be good, given the good resistance of the solid polymers to acids, alkalis, and solvents. There is far less published on the fire resistance of polyolefin foams than on polyurethanes. Nevertheless there are fire retardant grades (426). The products of combustion are likely not to be toxic. Inflammable blowing agents are a fire risk when they diffuse from the foam during storage (233).

3 Processing Park’s review (303) covers the processes used in 1991, and the blowing agents then available, mainly chlorofluorocarbons (CFC). Eaves and Witten (224) subsequently described the Zotefoams process in which nitrogen is dissolved into crosslinked polyolefin sheets in a high pressure autoclave, then expanded into foams in two stages. Recent research has concentrated on the refinement of existing processes, and the development of rotomoulding and microcellular foam processes. These two processes may not become significant; papers tend to appear just after a process is commercialised, or when its development is abandoned.

3.1 Melt Rheology Suitable for Foaming When low density foams are produced, the polymer melt must undergo high biaxial extension in order to

6

form the thin cell faces. Its flow properties, or ‘rheology’ must suit the process. Melts of high molecular weight polymers are highly viscous, and there is an elastic contribution to their deformation. The melt must sustain high tensile stresses without cell face fracture; if it occurs, neighbouring cells will join, and repeated fracture will lead to very large cells, then foam collapses. Once the foam has formed, its geometry must remain stable while the thermoplastic cools and solidifies, and in subsequent storage. This means that the diffusion rate of the gas through the cell faces must be low. As diffusion from foams can be very slow, there may be changes in the product dimensions for a long period after initial manufacture. Crosslinked PE is stable during foaming. Crosslinked metallocene linear low density PE (LLDPE) (100) was characterised in terms of melt moduli (C; Equation (4) of Section 2.2): the foam relative density increased as the gel fraction increased. The melt extensional response of the same polymer without crosslinking was unsuitable for foaming (66). However, the addition of 3% of a lightly crosslinked version of the same polymer allowed stable foams to be made. Silane crosslinking of metallocene PE (146) has lower capital cost than conventional peroxide or radiation crosslinking. However the process was unfeasible for PE foams until branched metallocene PE was available. The foams can have densities down to 16 kg m-3. It is also possible to make open cell foams based on low crystallinity PE copolymers that can compete with polyurethane and PVC open cell foams. The polymer gel content, measured using solvent extraction, is used to characterise the degree of crosslinking of polyolefins. There is a theoretical relationship between these quantities if the crosslinking is assumed to occur at random points. For most foam processes the polymer must flow, yet have a high melt elasticity, so the gel content should not be too high. Papers that cover this aspect are available for ethylene vinyl acetate (EVA) copolymers (16) (285) (304) (308), LDPE/EVA blends (285) (308) and low density PE (LDPE) (308). As the gel content increases, so does the elastic modulus of the melt, so by the theory in Section 2.2, the density of the foam will also increase. An increased gel content will increase the tensile strength of the molten polymer, so making the foaming process more stable. One way to characterise thermoplastic melts is by using a ‘Rheotens’ machine (31) which subjects an extruded strand of melt to tensile elongation at a fixed velocity while measuring the tensile force. The typical response (melt tensile force versus draw velocity) for branched PP extends to twice as high a draw velocity, with six times the force, than that for linear PP. Alternatively a

Polyolefin Foams

Rheometrics extensional viscometer gives graphs of extensional viscosity growth function versus time for the tensile extension of a polymer melt rod (230) (401). The graphs for branched PP show an upturn at high times while those for conventional linear PP show a downturn. These differences are reflected in the foam structures produced: a low density foam with polyhedral cells for the high melt strength (HMS) PP, compared with a high density foam with near spherical bubbles for the conventional PP. The effect of butane level and melt temperature on the foam density (which can be as low as 15 kg m-3) was explored (31). The homopolymer foam is rather stiff and brittle, but blends made with a PP block copolymer have reduced modulus and increased toughness; however there is a maximum copolymer content for the production of low density foam.

3.2 Foam Expansion One challenge has been to use blowing agents that do not harm the environment, and allow the production of closed-cell, small cell size foam. CFC used in the past, such as CFC11 (CCl3F), had several advantages: the heat of fusion of the liquids aided the temperature control of the foams, the low diffusivity of the gases meant that stable cell structures were easy to achieve and the gases are non-flammable. In the last decade the technology of using pentane and butane has been developed. These have the disadvantages of being gases at room temperature, being flammable, and having a high diffusivity through molten polyolefins. The efficiency of azodicarbonamide and sodium bicarbonate blowing agents for PE foams was considered (253). These systems, which generate CO2 gas, are more suitable for compression moulding of foams. Blends of the blowing agents have a reduced exotherm, so are more suitable for polymer systems that are temperature sensitive, such as ethylene copolymers. When a high melt strength PP was foamed using butane (26), the maximum expansion ratio was a function of the extrudate temperature. It increased with increasing temperature while the expansion was limited by crystallisation, then decreased at higher temperatures due to the loss of butane from the extrudate. Direct observations of the extrudate showed how die swell was followed by foaming. Several strategies were used to achieve ultra-low density PP foams (68); branched PP prevents cell coalescence by preventing face fracture, lowering the melt temperature reduced the gas loss during expansion, and optimisation of the die design avoided too rapid crystallisation. Hydrocerol, a mixture of sodium

bicarbonate and citric acid which decomposes to liberate CO2 and a mixture of other products, can be used as a blowing agent (275). The CO2 acted as a blowing agent in combination with iso-butane. Optimisation of the extruder screw speed and the hydrocerol concentration controlled the nucleation density, hence the foam density and mean cell size. Branched PP had a slightly larger cell size than linear PP when CO2 was used as the foaming agent, but there were a significant number of open cells in the foamed linear PP (273).

3.2.1 Control of Cell Size and Cell Stability Cell nucleation is achieved by the use of nucleating agents. Calcium carbonate particles of diameter 3 to 17 μm were used (2) to nucleate LDPE foams and achieve foam densities in the range of 500 to 800 kg m-3. Talc is a more effective nucleating agent for PP foams than calcium carbonate (2), probably due to its platelet geometry; the concentration of nuclei appeared to increase almost exponentially with the concentration of talc, with the smallest particle size 0.8 μm talc being most effective. Low density foams of high density PE (HDPE) can be extruded with fine cells, using CO2 as a blowing agent (204). The melt temperature was reduced to the lowest possible value of 121 °C at the die, to avoid cell coalescence and achieve high expansion ratios. In related research (142), a blend of LDPE and LLDPE, blown with CO2 was extruded at 220 °C. It was necessary to cool the extrudate surface to temperatures as low as 0 °C to stabilise the foam. Gendron and Vachon (36), reviewing Park’s research (274) on PP foam, defined a foamability factor F from the tan δ of the PE melt (at 190 °C and 1 Hz), the average cell diameter D and the foam density ρ as: F = ρΔ(tan δ)0.75 ≤ 1.8

(1)

Tan δ is defined as the ratio E´/E´´ of the in-phase to the out-of-phase components of the complex Young’s modulus of the melt; a sinusoidally varying shear strain is applied to the melt, and the sinusoidally varying shear stress leads in phase by the angle δ radians. The condition in Equation (1) is for production of closed cell foam. The optimum processing window has limits on both melt viscosity and melt elasticity (Figure 4). The figure shows how the crosslinking of a polymer, of initially moderate molecular weight, to just below the gel point, produces the optimum structure. The LDPE blown film process is successful with a thermoplastic, since the cooling of the melt bubble is extremely fast (a few seconds), so there is little time

7

Polyolefin Foams

Figure 4 Influence of melt viscosity and tan δ, measured at a frequency of 10 Hz, on the stability of a LDPE foam (redrawn from (36)). For linear polymers of different molecular weights, crosslinking moves the properties in the direction of the large arrow

for the viscous extensional flow of the melt. However, due to the low thermal diffusivity of foams, it takes in the order of 20 minutes for the PE in a foam to cool from the melt to the solid state. During this time, the melt bubbles must remain stable. The typical gel content in the 30 to 70% range causes the low-shearrate viscosity to be extremely high. However, if the gelation were taken further, the tensile stresses in the expanded foam would be too high (see below for the melt expansion theory). If tan δ is high, so are the tensile stresses when the foam face polymer is subjected to biaxial extension. The foam faces may fracture if the tensile stress exceeds a critical level. The consequence of such fractures is the growth of abnormally large cells, with more than the usual 14 or 15 faces (Figure 5).

Figure 5 Abnormally large cells, with >20 faces, formed by cell face collapse in EVA foam of density 150 kg m-3, with a background of normal cells (a.9)

3.2.2 Control of Density In general the foam density reduces as the amount of blowing agent is increased, with a lower limit set by foam stability. It is possible to model the factors which affect the final density; Mahapatro and co-workers (206) used a regular Kelvin foam model to analyse the expansion of PE foams. The foam has uniform sized cells, each with eight hexagonal faces and four square

8

faces, all with the same edge length. They found the biaxial tensile stress σf in the molten cell faces to be: σf =

3 pr 2R

(2)

where R is the foam relative density, and pr the relative pressure in the cells. The concentration of blowing agent

Polyolefin Foams

determines the molar concentration of gas. The mean biaxial extension ratio λf in the faces is given by: λf =

1.703 3

(3)

R

For the biaxial extension of partly crosslinked PE melt, the tensile stress is given by:

(

σ f = C λ2f − λ−f4

)

(4)

where C is a melt modulus. The solution, for a particular formulation and process conditions, lies at the intersection of two graphs of face stress versus foam density, one representing Equations (3) and (4) and the other Equation (2) and a relationship between the gas pressure and volume. The rubber-like stresses in lightly crosslinked LDPE foams are of the order of 100 kPa, the biaxial draw ratio is of the order of 4, and the foam density is only slightly reduced from the free-expansion value.

3.3 Post-Extrusion Shrinkage The Zotefoams process (224), using crosslinked PE and nitrogen as the expanding gas, provides the best control of cell diameter. The block is cut into sheets when cold, giving full control of the sheet thickness. If the foam is not crosslinked, the post-extrusion shrinkage is worse, due to the nature of the blowing agents used. The diffusion rate of CFC (used in the past) out of PE foams was much lower than the diffusion rate of air into the foam, so the product dimensions were stable. However, pentane or iso-butane escapes faster from the foam than air enters, so there is a risk of collapse of the foam dimensions. Yang and co-workers (a.10) modelled the diffusion of gas from LDPE foam of density 22 kg m-3, with diffusivities of 1.73 x 10-6 m2 h-1 and 0.26 x 10-6 m2 h-1 for air and isobutane, respectively. For LDPE alone there was a 40% shrinkage of thickness soon after extrusion and a gradual thickness increase that was incomplete after one year. However, the addition of glycerol monostearate lead to a sheet with a stable thickness after five days of storage. If the LDPE was blended with an unspecified ethylene-styrene interpolymer (ESI), this roughly halved the thickness changes, but did not alter their time scale. The effect of the ESI was attributed to the increase in polymer Young’s modulus. In a further paper (a.11) they explored the effects of foam density, cell size, and polymer modulus on the rate of diffusion induced dimensional changes for LDPE foams blown with isobutene.

Ageing modifiers (stearamides, mono-glycerides) are used (147) for extruded LDPE foam, blown with isobutene. Shrinkage of the length of extrudate occurred over a period of about a month. Some of these modifiers have anti-static properties, important when a flammable gas is used as the blowing agent. A distilled monoglyceride was the most effective at stabilising the dimensions. Bouma and co-workers (255) considered a range of alkane blowing agents. Nauta (a.6) provides details of the science. Table 1 gives the permeabilities of LDPE films measured in units of Barrer = 10-10 cm3(STP)·cm/(cm2·s·cm Hg). Films were used rather than foam, since it is impossible to accurately know the geometry of the polymer in the latter. However the orientation of the polymer crystals in the film may differ from those in foam faces. The permeability of n-butane is five times greater than that of air through LDPE film without the additive, but only one-third of the value when the stearyl stearamide is added. A film of this occurs on the surface of the LDPE film. It is assumed, that in LDPE foams, the stearyl stearamide has had time to migrate to the cell faces surfaces, where it acts as a barrier to butene. Heat treatment of the LDPE film (1 hour at 83 °C) reduces the diffusivity of the PE to butene, but not to air. It hardly changes the solubility of butene in the PE. Volume changes, due to the diffusion of the gases from a 5 mm thick foam sheet of density 28 kg m-3, with cell diameter 0.45 mm and face thickness 4 μm, was measured: results are shown in Figure 6 (a.6). Modelling of the process could reproduce the experimental data. The volume contraction due to the loss of butene occurs in less than 1 hour, while the volume expansion due to air ingress is not complete after 3 days, for this thin slice of foam. When PE is extruded as 75 mm or thicker planks, the processes become slower. Assuming that Fick’s law applies to the diffusion, the time, for a certain % gas loss,

Table 1 Permeabilities and diffusion coefficients for LDPE films Permeability (Barrer)

Permeating gas

LDPE LDPE + 2% SS

Diffusion coefficient at 30 °C, heat treated (10-6 mm2 s-1) LDPE

LDPE + 2% SS

Air

1.0

0.6

72

54

n-butane

5.3

0.2

4.8

1. 9

SS: stearyl stearamide

9

Polyolefin Foams

Figure 6 Volume changes due to diffusion of butene from, and air into, a 5 mm thick foam sheet of density 28 kg m-3 , with and without stearyl stearamide additive (redrawn from a.6)

increases with the square of the thickness of the foam sheet. When the crystallinity of polyethylenes is increased, the gas permeability through the film decreases. The factors involved are the tortuosity of the gas path through the amorphous phase, and the effect of the crystals in restricting the mobility of the amorphous polymer chains (chain immobilisation factor). The logarithm of the permeability of nitrogen, argon and carbon dioxide decreased almost linearly with increased crystallinity of PE, with the ratio of the gas values remaining almost constant for a particular PE.

3.4 Rotomoulding The rheology (or molecular weight distribution; MWD) of PE needed for rotomoulding is different than that for foam extrusion, and the final structure is closer to that of ‘structural foam’ injection moulding, with isolated bubbles. The rotomoulding of a 32 mm diameter cylinder from LLDPE was investigated (198). EVA was added so that the low viscosity melt would form a solid skin, and sodium bicarbonate was used as a blowing agent. The foam expansion was only by a factor of eight, and the mould was nearly filled with the foamed polymer. Significant cell coarsening occurred in the 20 minutes during which the polymer was heating. A density variation was typically found (160) through 10 mm thick moulded parts, which affects the mechanical properties. The oxidative degradation during the 40 minute cycle is most severe

10

near the inner surface. Consequently the polymer needs to be stabilised. Rotomoulded PE parts have a low sound transfer, high bending stiffness and good thermal insulation (87). If 2 to 3 mm diameter pellets were used in place of the usual 0.2 to 0.4 mm powder for the process, there were severe thickness variations in the product. Compared with fully-dense rotomoulded parts, the use of foam improved the impact strength, but reduced the tensile strength, and increased the cycle time.

3.5 Microcellular Foams The microcellular foaming process was developed by Suh (a.12), who defined microcellular foams as having a cell diameter <30 μm. The original aims were reduce the density of bulk polymers without sacrificing the toughness. If the bubble size were smaller than the size of existing flaws in the polymer, the toughness would not be compromised. A reduction in density allowed either a reduction in the mass of a product, or an increase in thickness, hence bending stiffness, at a constant mass. This was originally a very slow batch process, because of the need to dissolve gaseous CO2 in solid glassy polymers such as polycarbonate and polystyrene. The low diffusivity meant that the time taken was many hours. The foam was formed when there was a phase change from the glassy to the melt state. In recent developments of the process, supercritical CO2 (for temperatures >31 °C, and pressures >7.2 MPa) is

Polyolefin Foams

introduced into molten polymers in the screw of an extruder, consequently there is no longer a polymer phase change on foaming. Because of the shear mixing of the extruder, the diffusion distance in the polymer/CO2 mixture can be of the order of 0.1 mm. Consequently the dissolution time can be reduced to the order of seconds. In the foaming stage, pressure release on passing through a die must be rapid. Suh compares the effect of two nozzles, for the same flow rate of 2 x 10-7 m3 s-1. The pressure drop through the die causes the foaming process, in which some bubbles nucleate before others (Table 2). If the bubble nucleation time is much smaller than the time for gas to diffuse to a growing bubble, further bubbles will nucleate rather than existing bubbles grow. If there is gas diffusion to a bubble, this depletes the surrounding melt of gas and prevents nucleating in this region. The high pressure release rate is necessary for fine bubbles. There is however an influence of the polymer. Suh shows that PE can be saturated with CO2 at 54 °C at a pressure of 3.4 MPa. When such a PE was foamed in the melt at 150 °C, the cell diameter could be as low as 0.1 μm, whereas if the semicrystalline PE was foamed at 20 °C the cell diameter was 1.5 μm.

Table 2 Die dimensions and residence time for microcellular foam extrusion Radius, Length, mm mm

Residence time, s

Pressure drop rate, GPa s-1

0.60

87

0.51

0.076

0.23

13

0.011

3.5

The small cell size only has limited effects on properties, but can have advantages for further processing. If foamed sheet is to be thermoformed, it must have a cell diameter much less than the sheet thickness to avoid failure. The Young’s modulus and compressive strength are hardly affected by the cell size. Properties such as thermal conductivity are functions of cell size, due to the influence on radiation heat transfer. These foams have been commercialised by Trexel, both for the extrusion of sheet, and for injection moulding (63). PP foam sheet, of density in the range 0.57 to 0.75 g/cm3 and cell size <0.1 mm, allowed thermoforming without excessive cell growth. The product offers 20 to 25% material savings for the same bending stiffness. Extruded profiles (a.8) of ethylene-propylene-diene monomer (EPDM) rubber are used for automotive weather seals.

Some microcellular mouldings (56) are similar to ‘structural foam’ mouldings, in having a solid skin about 1 mm thick, and a foamed core. However, the spherical cells in structural foam tend to be 0.2 mm to 1 mm in diameter. The structural foam injection moulding process has the great advantage of injecting a gas/polymer melt mixture of much lower viscosity than a polymer melt alone. The consequent ten-fold reduction in the injection pressures, lead to lower cost moulds (cast aluminium in place of hardened steel) and a lower cost process. Structural foam mouldings have been highly successful for large moulding (TV set cabinets, bed frames, etc.), in contrast with the limited commercialisation of microcellular foams. The mechanics of the mouldings can be treated by sandwich beam theory (13), which explains the higher bending stiffness to mass ratio, compared with conventional injection mouldings. These foams allow tests of cell nucleation theories, especially the role of foam shear (6). An LDPE melt with nano-scale CaCO3 as a nucleating agent, was extruded through a slit die. A high screw rotation speed, which made the shear energy of the melt greater than the surface free energy of a bubble, increased the cell density markedly. Calcium carbonate nucleating agents were also used with ethylene-octene copolymers (128). The products had relative densities in the range 0.4 to 0.7, and the relative modulus and tensile strength were proportional to the relative density.

3.6 Oriented PP Foams – Strandfoam Dow Strandfoam is a PP foam with oriented elongated cells, as in wood, aluminium or paper honeycomb. A high melt strength PP is extruded using a multiple orifice die, having 722 holes of diameter 1 mm (116). The blowing agent must be highly soluble in the melt, yet have a low permeability at room temperature. A 60/40 mixture of a hydrochlorofluorocarbon (HCFC) (having a much lower permeability in PP than air) and ethylene chloride (much higher permeability) was optimal in achieving dimensional stability of the extruded plank. To obtain foams with >80% closed cells, low foam densities and small cell sizes (typically 20 kg m-3 density and 0.9 mm cell diameter) were required. After extrusion the bundle of extrudates are fused together, by low-friction plates which press on the extrudate sides, consolidating them into an hexagonal array. The anisotropic material produced competes with paper or metal honeycomb. Slices, cut across the extrudate, have the strong direction normal to the slice surface, which is optimal for the cores of sandwich structures. The latter rely on high modulus

11

Polyolefin Foams

skins to provide the bending stiffness; the role of the core is to keep the skins at constant separation, which means that they must have a high compressive strength normal to the sheet, and a high shear modulus to prevent easy shear of the sandwich structure. Strandfoam cannot be produced with a varying cell axis direction. This means that it is unsuitable for curved products such as helmet liners, for which the high yield stress direction must vary in the product. In automobiles it is used for occupant protection; complex shapes can be sawn from block, cut by abrasive wires, or thermoformed.

4 Mechanical Properties Foam mechanical properties are often explained using Gibson and Ashby’s (a.13) approach. Their oversimplified microstructural models based on twodimensional honeycomb structures, are almost analogies; the model geometry bears little relation to that of polyolefin foams. They give power law relationships between properties such as the Young’s modulus of the foam, EF, the relative density of the foam, R, and the corresponding polymer property. They characterise polyethylene foam as elastomeric, stating that the compressive response has three regions: initial elastic, a plateau region due to elastic buckling, and a densification region at high strains. However PE (or PP) foam is neither elastomeric, nor does it have a plateau region in compression. The initial compressive response will be considered first. As all polyolefin foams are viscoelastic (see Section 4.6 on creep), as are the polymers from which they are made, and the response is non-linear with strain, the concept of a Young’s modulus is an approximation. Although it is convenient to use such a concept, it must be treated as both time and strain dependent.

4.1 Initial Response in Compression For closed cell foams Gibson and Ashby predict three contributions to the Young’s modulus of the foam: EF = C1 RE2 EP + C2 RF EP + p0

1− 2ν 1− R

(5)

which come from the bending of cell edges, the stretching of cell faces and the compression of the cell gas. p0 is the atmospheric pressure, ν is Poisson’s ratio, R is the relative density, RE and RF are the volume

12

fractions of polymer in the edges and faces, respectively, while EP is the Young’s modulus of the polymer. The constants C1 and C2 in the equation are found by fitting the equation to experimental data (presented as log – log graphs, as done by Benning (a.2-a.4)). C1 turns out to be approximately 1.0 for open cell foams; this value is then repeatedly used in equations, suggesting to some readers that it is a prediction of the GibsonAshby model. This approach suggests that polyolefin foams are linear elastic materials, with Young’s moduli that are independent of time and temperature. Clutton and Rice (383) used Equation (5) to fit the data for the Young’s modulus of LDPE and EVA foams and deduced that there is a 13% fraction of the polymer in the cell faces! This false deduction is at variance with observations of the microstructure. Micromechanics theories for closed cell foams are less well advanced for than those for open cell foams. The elastic moduli of the closed-cell Kelvin foam were obtained by Finite Element Analysis (FEA) by Kraynik and co-workers (a.14), and the high strain compressive response predicted by Mills and Zhu (a.15). The Young’s moduli predicted by the Kraynik model, which assumes the cell faces remain flat, lie above the experimental data (Figure 7), while those predicted by the Mills and Zhu model, which assumes that inplane compressive stresses will buckle faces, lie beneath the data. The experimental data is closer to the Mills and Zhu model at low densities, but closer to the Kraynik theory at high foam densities. Polyolefin foams are easier to model than polyurethane (PU) foams, since the polymer mechanical properties does not change with foam density. An increase in water content decreases the density of PU foams, but increases the hard block content of the PU, hence increasing its Young’s modulus. However, the microstructure of semi-crystalline PE and PP in foams is not spherulitic, as in bulk mouldings. RodriguezPerez and co-workers (20) showed that the cell faces in PE foams contain oriented crystals. Consequently, their properties are anisotropic. Mechanical data for PE or PP injection mouldings should not be used for modelling foam properties. Ideally the mechanical properties of the PE/PP in the cell faces should be measured. However, as such data is not available, it is possible to use data for blown PE film, since this is also biaxially stretched, and the ‘texture’ of the crystalline orientation is known to be similar to that in foam faces. Simone and Gibson (a.16) predicted the effect of wrinkled cell faces (in aluminium closed cell foams), on the Young’s modulus, by FEA of a modified Kelvin

Polyolefin Foams

Figure 7 Young’s modulus for LDPE foams versus relative density, compared with predictions for the Kelvin foam (a.15)

foam. This showed that the Young’s modulus could be reduced by a factor of 10 from the flat face version.

4.2 Bulk Modulus The faces in low density LDPE foams are partly buckled or wrinkled, as a result of processing (a.17). This affects both the bulk modulus and the Young’s modulus. The foam bulk modulus KF is predicted, using the Kelvin closed cell foam model, to be: KF =

2E R + pa 9( 1 − ν )

(6)

where the 2nd term on the right-hand side is the contribution from the cell air. However the experimental values are a factor of four lower, due to the cell face wrinkling.

4.3 Compressive Collapse Gibson and Ashby (a.13) propose separate models for elastic collapse by cell edge buckling and plastic collapse by stretching of cell faces. The latter model gave a scaling relationship between the (initial) collapse stress σ*pl and the relative densities: σ *pl = C5YRe1.5 + C6 YR f

where C5 and C6 are empirical constants, Y is the polymer tensile yield stress, and Re, Rf are the volume fractions of cell edges and faces. A fit of Equation (7) to scattered data, for PS, PVC and rigid PU foam yield stresses versus relative density, lead to the tentative conclusion that C5 = 0.3 and C6 = 0, implying that the cell faces have no effect on the collapse stress. In reality, the microstructure of LDPE foams remains very similar as the density increases from 18 to 100 kg m-3, the main changes being in the cell face thickness. The fraction of polymer in the cell faces is greater than 70%, and the initial compressive yield stress of LDPE varies approximately with the 1.5th power of the density (a.15). This does not mean that the model behind Equation (7) is appropriate.

4.4 High Strain Compressive Response When a closed cell foam is uniaxially compressed, it can be assumed that the compressive stress is a sum of the stresses taken by the polymer structure and that taken by the cell gas. For a foam with zero lateral expansion when uniaxially compressed, and isothermal gas compression, the latter contribution σG is given by (295): σG =

pa ε 1− ε − R

(8)

(7)

13

Polyolefin Foams

where pa is atmospheric pressure (the gas pressure in the undeformed foam cells, if the foam has been stored at atmospheric pressure for some time), ε is the applied compressive strain, and R the foam relative density. The variable ε/(1-ε-R) will be referred to as the gas volumetric strain. If the polymer contribution σ0 is a constant value, plus a contribution proportional to the gas volumetric strain, the total stress is: σ = σ0 +

p0 ε 1− ε − R

(9)

p0 is now the ‘effective gas pressure’ in the cells. σ0 can be evaluated by fitting a graph of stress against the gas volumetric strain, and extrapolating to zero strain (295). Clutton and Rice (383) did this and found that the value of p0 often did not equal 101.3 kPa (standard atmospheric pressure). The loading response has two regions: the initial ‘elastic’ one, and a post-yield region where the hardening is dominated by the cell gas compression. There is no division of the post-yield region into a plateau and a densification region. The post-yield data for Instron loading of expanded polystyrene (EPP) foam of density 43 kg m -3 in Figure 8 (254) can be fitted by σ0 = 200 kPa, p0 = 159 kPa. As the unloading response is separate from the loading response, these foams cannot be considered as ‘elastomeric’. Mills and Zhu (a.15) used a Kelvin foam model, in which face tensions restrain the bending of cell edges

that are oblique to the compressive stress axis. The cell faces are assumed to wrinkle if they are subjected to compressive in-plane stresses, hence they cannot support such stresses. The model predicts the compressive collapse stress of a LDPE foam of relative density of 0.025 to be about 30 kPa; this value declines slightly at compressive strains >30%. However, the majority of the stress at 50% strain is taken by the compressed cell air. Consequently the predicted compressive stress-strain graph is close to the experimental one measured under impact conditions. Predictions for stiffer foams, such as polystyrene, are less accurate. As the model relies on at least 40% of the polymer being in the cell edges, its results are extrapolated to foams with about 10% of the polymer in the cell edges. The model predicts that cell faces will yield in tension when the foam compressive strain is >10%. Techniques such as X-ray computerised tomography are needed to explore the wrinkling and stretching of cell faces in the interior of the foam, to confirm the deformation mechanisms in the model.

4.5 Heat Transfer from Gas to Polymer During High Strain Compression Mills and Gilchrist (270) analysed the heat transfer that occurs when closed cell foams are subjected to impact, to predict the effect on the uniaxial compression stressstrain curve. Transient heat conduction from the hot compressed gas to the cell walls occurs on the 10 ms

Figure 8 Compressive stress versus gas volumetric strain curve, for EPP foam of density 43 kg m-3 (254). The loading curve is fitted with Equation (9)

14

Polyolefin Foams

timescale of an impact. If the heat transfer is only by conduction in the gas, the predicted air temperature rise and the effect of cell size are too great, hence there must be heat transfer by gas flow in the deformed cells. For compression tests on a one minute timescale, isothermal conditions prevail for all cell sizes. As gas heating becomes significant, the strain hardening rate increases. The hysteresis (difference between the loading and unloading stress-strain curves) due to heat transfer is predicted to be a maximum for cells of a certain diameter. Poisson’s ratio, measured at high compressive strains, was found to be near-zero for polystyrene and polypropylene bead foams, but about 0.2 for LDPE foam. The larger the Poisson’s ratio, the less is the gas compression contribution to strain hardening. Figure 9 shows, when a low density LDPE foam (with zero initial yield stress) of cell diameter 1.0 mm is impact compressed to 81% strain, the predicted air temperature rises by a maximum of 93 °C but the polymer rises by a maximum of 8 °C. If these foams are subjected to an extreme impact, such as when they bottom out between a hemispherical striker and a flat support table, the temperature rise will be higher, resulting in PE melting and cell fracture – a hole occurs in the protective product surrounded by PE that has melted.

4.6 Creep Response and Air Loss from Cells When products are stored in warehouses for long periods, the foam packaging must not creep by more than about 10%, or the impact protection will

deteriorate. The creep compliance J(t) is defined as the creep strain e(t) divided by the constant applied stress. For EVA and LDPE foams, the creep compliance function, for low stresses, could be described by: J (t ) = J 0 t n

(10)

where J0 and n are constants. As a similar relationship applied for the creep of the solid polymer, the foam creep is controlled by the polymer viscoelasticity for this region. At strains >10%, when the polymer structure has begun to collapse, gas loss, by diffusion through the cell faces of closed cell foams, may contribute to the creep. The effect of this on the creep of LDPE and EVA foams was determined (266). The foam diffusivity for air was predicted from the polymer permeability P and the foam density ρ using: DF =

6 P pa φρ

(11)

where pa is atmospheric pressure and φ the fraction of polymer in the cell faces. Consequently, the lower the foam density, the higher is its diffusivity. As the initial yield stress of the foam falls with approximately the 1.5th power of density, low density foams largely depend on their cell air for their compressive resistance. The combination, of this and the high foam diffusivity for air, means that they are poor at resisting creep when

Figure 9 Predicted temperature rises in the air and polymer, compared with the compressive stress level, when a LDPE foam with cell diameter 1.0 mm is impact compressed to 81% strain (270)

15

Polyolefin Foams

stored for long periods under load. Low density foams made from low crystallinity polymers such as EVA (which have high permeabilities), will have particularly high permeabilities. These foams will have high creep rates if the stresses cause creep strains >10%. The foam was assumed to have a yield stress σy, with a time dependence given by:

σY =

εY t− n J0 F

block half thickness = 8 mm, cell pressure (p0) = 100 kPa, initial yield stress = 120 kPa, yield strain = 0.1, 1 s compliance = 600 x 10-9 Pa-1, compliance slope (n) = 0.06, relative density = 0.26, fraction of polymer in cell faces (φ) = 1.0, Poisson’s ratio = 0.07, and foam diffusivity = 100 p m2s-1.

(12)

The creep stress was assumed to be shared between the polymer structure yield stress and the cell gas pressure. A finite difference model was used to model the gas loss rate, and thereby predict the creep curves. In this model the gas diffusion direction was assumed to be perpendicular to the line of action of the compressive stress, as the strain is uniform through the thickness, but the gas pressure varies from the side to the centre of the foam block. In a later variant of the model, the diffusion direction was taken to be parallel to the compressive stress axis. Figure 10 compares experimental creep curves with those predicted for an EVA foam of density 270 kg m-3 used in running shoes (90), using the parameters:

The predicted creep curves, and the slope increase after 105 s are matched. However, the separation of the predicted curves, for 50 kPa increments of creep stress, is too large for the range 100 to 200 kPa, when the creep strains are in the range 10% to 40%. The polymer structure contribution to the creep stress probably is not constant for 0.7 > ε > 0.1, as assumed in the model. The predicted creep rate slows when the strain exceeds 70%, not 65% as in the experiments. Hence the effect of cell face touching at high strains, may be slightly different from that assumed. Although there is significant gas loss when high compressive stresses are applied continuously for several hours, these conditions do apply to running, where the stress peaks last

Figure 10 Creep curves for EVA foam of density 275 kg m-3, and the modelling predictions (parameters in text) at the compressive stress levels in kPa shown (254)

16

Polyolefin Foams

0.1 second. Consequently gas loss is not a cause of fatigue deterioration of EVA foam in running shoes. The isochronous stress-strain curves for the creep of PP bead foams (254) were analysed to determine the effective cell gas pressure p0 and initial yield stress σ0 as a function of time under load (Figure 11). p0 falls below atmospheric pressure after 100 second, and majority of the cell air is lost between 100 and 10,000 s. Air loss is more rapid than in extruded PP foams, because of the small bead size and the open channels at the bead boundaries. σ0 reduces rapidly at short yield times <1 second, due to proximity of the glass transition, and continues to fall at long times. Table 3 shows values for the foam permeability to air, deduced from creep experiments. Verdejo (a.9) measured a value of 70 x 10-12 m2 s-1 for EVA foam

Table 3 Diffusivity of foams for air, estimated from creep analysis Density

Estimated diffusivity 10-12 m2 s-1

Reference

EVA

35

1000

(295)

EVA

270

100

(90)

LDPE

24

250 to 500

(295)

LDPE

70

250

(295)

Polymer

with a density of 152 kg m-3. This and the measured 480 x 10-12 m2 s-1 value for PE foam of density 20 kg m-3 (Section 2.3) shows that the estimated values in Table 3 are of the correct order of magnitude.

4.7 Recovery After Creep After a foam has been subjected to creep loading, the recovery when the stress is removed is a slow process (254) (266). For LDPE, EVA and PP foams, subjected to creep for 106 seconds, it appears that 100% recovery from the high creep strains will eventually occur, but that this will take longer than 106 seconds; the fraction of the creep strain that remained had reduced to <10%. There is no parallel between the shape of the creep curve and that of the creep recovery graph, suggesting that the deformation mechanisms occur in a different order. Thus there is no parallel with the creep and recovery of solid polymers, where linear viscoelastic theory may apply. If a significant percentage of the cell air has diffused out of the foam during creep, the overall recovery will be slow; there will be a weak viscoelastic recovery, hindered by the slow re-entry of air to the foam. If there were permanent plastic deformation of any of the foam structure (such as the formation of folded ‘hinges’ in cell faces), there would be a residual strain after ‘infinite’ creep recovery time. After high strain compressive creep in EVA foam of density 275 kg m-3 the strain recovered to 15% after 106.5 seconds, but the recovery rate had slowed, so some permanent deformation was possible (90).

Figure 11 Variation of cell gas pressure and initial yield stress for PP foam of density 20 kg m-3, versus logarithm of the time under load (254)

17

Polyolefin Foams

Although, in principle it is now possible to study deformation of internal cells in foams using CT microtomography, no such research has been reported.

4.8 Fatigue Fatigue loading may occur to packaging in transit. However the frequency and amplitude of vibration is unlikely to be constant. Fatigue tests on PE foams (166) using a saw tooth displacement versus time profile, revealed the effects expected for viscoelastic polymers. Increasing the test speed caused the compressive stress to increase. An increase in the foam temperature occurred as a result of the dissipation of energy per cycle. The increase in temperature partly compensated for the increase in testing speed. The maximum stress in the fatigue loading cycle decreased by 20 to 30% from the initial value (whether this was the result of the temperature increase or changes to the polymer structure, was not revealed). For the EVA foam midsoles of running shoes, the durability for repeated impact appears to improve with increased density. However the polymer contribution to the impact response reduces after simulated (and real) use (a.18), since wrinkles and some holes appear in the cell walls. Consequently these applications require high density foams.

4.9 Cushion Curves for Impact Response The initial design of foam packaging often uses ‘cushion curves’, which summarise the results of a large set of impact drop tests, in which the foam dimensions, drop mass and drop height are varied. However, the cushion curves can be derived from a single instrumented compressive impact test (325). For LDPE foams there is a minor amount of viscoelastic response in the impact stress strain curve, so the loading part thereof (for impacts with a range of energies) almost follows a mastercurve. This provides a good method of checking the cushion curves for a range of foam thicknesses and drop heights. The approach has been confirmed by Burgess (320) among others. The ordinate of the cushion curve is the static stress σs, the compressive stress experienced by the foam when the product is stored: σS =

18

mg A

(13)

where A is the foam cross-sectional area. For a given drop height h, the kinetic energy of the packaged product of mass m, at the moment of impact, is mgh. When the object has momentarily stopped, energy mgh has been input into a foam block(s) of initial volume At. Therefore the energy density U (J m-3) input into the foam is: σm

( ) ∫σ

U σm ≡

dε =

0

mgh At

(14)

The integral U( σm) represents the area under the engineering stress-strain master curve up to the maximum stress σm. The static stress is a function of the energy density function U(σm): σs =

t U( σ M ) h

(15)

The maximum product acceleration G, which occurs when the foam compressive stress has its maximum value σm, is given by: G=

h σM g t U( σ M )

(16)

The parameters σs and G of the cushion curve can be calculated from the energy density function U(σm), using Equations (13) and (14). These equations only contain the ratio t/h of the foam dimensions, so the resulting cushion curves can be labelled with the reduced foam thickness = t/h.

4.10 Impact Response in Shear or Shear Plus Compression PP bead foams were subjected to oblique impacts (167), in which the material was compressed and sheared. This strain combination could occur when a cycle helmet hit a road surface. The results were compared with simple shear tests at low strain rates and to uniaxial compressive tests at impact strain rates. The observed shear hardening was greatest when there was no imposed density increase and practically zero when the angle of impact was less than 15 degrees. The shear hardening appeared to be a unique function of the main tensile extension ratio and was a polymer contribution, whereas the volumetric hardening was due to the isothermal compression of the cell gas. Foam material models for FEA needed to be reformulated to consider the physics of the hardening mechanisms, so their

Polyolefin Foams

predictions were reliable for foam impacts in which shear occurred.

4.11 Recovery After Impact The recovery behaviour of three HDPE closed cell foams was investigated (400) after they had been subjected to a high strain compressive impact. Cell deformation on the surface of the foam was observed during compression and recovery in a scanning electron microscope (SEM). Recovery occurs by the viscoelastic straightening of the buckled faces but it is incomplete due to some plastic deformation in the structure, so the faces remain slightly buckled. Some of the observed inhomogeneity of the cell deformation is due to the removal of cell faces in the sectioning for examination. There is little difference in the recovery dynamics as a result of changing the foam density. When Zotefoam HDPE materials of density 98 kg m-3 were subjected to a single major compressive impact (419), after recovery at 50 °C for 1 hour, the performance, defined as the energy density absorbed before the compressive stress reached 2.5 MPa was back to 75% of the initial value. Further severe impacts caused a further deterioration of the performance of the recovered foam. Peak compressive strains of 80 to 90% caused some permanent buckling of the cell walls of HDPE foams. The recovery is much slower than the 0.1 second impact time, so is not a conventional linear viscoelastic response. It must be driven by the compressed air in internal cells in the gas, with some contribution from viscoelasticity of the polymer. Recovery of dimensions had slowed to a very low rate after 106 seconds at 20 °C or after 105 seconds at 50 °C.

4.12 Multiple Impacts Some foam products are subjected to up to 10 major impacts in their lives, therefore a foam may need to be selected so that the performance is still adequate. Products, subjected to hundreds of thousands of impacts as in running shoe midsoles, were dealt with under fatigue. It appears that the higher density HDPE (419) and PP foams loose a significant amount of their protection after several impacts, but nevertheless it may be possible to use sufficient foam thickness to provide the required protection. If low density EVA foams are used, the impact energy densities are much lower, as the majority of the resistance is from compressing the cell gas. Ankrah and co-workers (33) performed multiple impacts on LDPE/ESI blend foams, and found

a minor deterioration in the impact response with impact number. If the foam was allowed 24 hours for recovery, the impact response was nearly fully restored. The biaxially oriented cell faces recover over a period of days from high compressive deformation of the foam. The dispersed leathery ESI responds roughly in a similar way to the LDPE.

5 Thermal Properties 5.1 Dynamic Mechanical Thermal Analysis (DMTA) This commercially available technique, used to characterise (55) foams, applies a sinusoidally varying compressive strain to a block of foam. Rodriguez-Perez and co-workers (94) (132) (259) and Ankrah and coworkers (33) used DMTA on PE and copolymer foams. They show that the Young’s modulus of the foam decreases significantly as the temperature increases. This parallels the response of bulk polymer, and is an important factor in the selection of foams. This steady decrease, on a graph of log modulus versus temperature, is typical of semi-crystalline polymers in the temperature range between the Tg of the amorphous phase and the melting temperature of the crystalline phase. Consequently all PE and PP foams have strongly temperature-dependent mechanical properties in the range 0 to 60 °C. This contrasts with foamed glassy polymers such as EPS. DMTA is a rapid technique for finding the temperature sensitivity of the foam; however more detailed mechanical tests may be needed to fully characterise the foam. An ethylene-octene copolymer with 25% octane (Engage 8150) has very low crystallinity; DMTA (55) shows that the main thermal transition is the Tg for the non-crystalline chain segments of –20 °C. The storage modulus values show that the polymer is effectively glassy at lower temperatures, and rubbery at higher temperatures. Tan δ quantifies the fraction of the input energy lost per cycle of deformation. The peaks in the graph of tan δ versus temperature can be assigned to various processes in the polymer; in PE the α relaxation process at about 50 °C is thought to occur in the crystalline lamellae, while the β relaxation process at about –10 °C is due to the movement of chain branch point. Each peak in tan δ is associated with a region in which the storage Young’s modulus decreases more rapidly with increasing temperature.

19

Polyolefin Foams

Rodriguez-Perez and co-workers (132) studied Aleolit and Alveolen LDPE foams made by Sekisui: these have oriented cells as a result of the stretching that occurs in the foam extrusion process. They found that the value of tan δ, at a given temperature (say 70 °C) and strain amplitude, decreased as the foam density increased, but were unable to explain the mechanism for this decrease. They suggest that the gas pressure inside the cells might have some influence on the DMTA response. It is possible that there are wrinkled cell faces in the lower density foams at ambient temperatures, and that the gas expansion on heating leads to the flattening of the faces, changing the response. Figure 12 shows the temperature variation of the inphase Young’s modulus E´ of an EVA foam (Verdejo, unpublished). E´ falls as the amorphous phase goes through a glass transition close to –10 °C, then again as the crystalline phase melts at 80 °C. The peaks in tan δ at these temperatures are labelled α and β.

5.2 Thermal Expansion A Kelvin foam model with planar cell faces was used (a.17) to predict the thermal expansion coefficient of LDPE foams as a function of density. The expansion of the heated gas is resisted by biaxial elastic stresses in the cell faces. However SEM shows that the cell faces are slightly wrinkled or buckled as a result of processing. This decreases the bulk modulus of the

foam, and lowers its resistance to the expanding cell gas. Therefore the thermal expansion coefficient is higher than that predicted by the model. If the experimental bulk modulus is used, the predicted thermal expansion coefficient is closer to the experimental value.

5.3 Thermal Conductivity PE foams are used in some thermal insulation applications (403) although they have higher thermal conductivities than low density PU foams, which have the majority of bulk insulation market. Crosslinked PE foams have a higher maximum user temperature than EPS, which has a Tg of about 90 °C. Rodriguez Perez and co-workers have studied the thermal conductivity of HDPE, LDPE and EVA foams (39) (61) (143) (151) (178) (238). Models are proposed that relate the thermal conductivity to proportion of polymer and gas in the foam, and polymer and air thermal conductivity. There are contributions to the thermal conductivity from conduction in the gas, conduction through the polymer and from radiation. The thermal conductivity decreases as the foam density decreases, because the conductivity of the polymer is higher than that of air. The thin cell faces are partially transparency to infra-red radiation. The radiation contribution, hence the thermal conductivity of the foam, can be reduced by using a small amount of black pigment in the PE. The radiation contribution also becomes smaller as the cell size

Figure 12 DMTA graph of storage Young’s modulus and damping (tan δ) versus temperature, for EVA foam of density 150 kg m-3 (a.9)

20

Polyolefin Foams

decreases, since there are more interfaces to absorb and re-radiate thermal energy (143). Black pigmented PE foam has a lower thermal conductivity than unpigmented foam since black cell faces absorb a greater proportion of the radiant energy in the infrared spectrum, rather than partially transmitting it.

2. Compute the cross-sectional area of each layer Ai 3. Increment the force applied to the rib by ΔF to Fj 4. Since the layers are loaded in series, the same force Fj acts on each layer. Hence the stress on layer i is: σi =

6 Applications Polyolefins have a spectrum of mechanical properties, ranging from almost-rigid EPP mouldings for helmets and factory containers to rubbery high density EPDM foams for mouse mats and grips on hand tools. Rather than list all these areas, five specific areas are described in detail.

Fj

(17)

Ai

5. Invert Equation (9) to compute the vertical compressive strain εi in the layer: εi =

σ − σ0 ( 1 − R) σ i − σ 0 − p0

(18)

6. The total deflection x is sum of the layer deflections

6.1 Packaging Against Impact Damage x=

The design of packaging is described in many places, including (295). Dow has a Millennium programme for designing packaging (a.19) with data for PE foams. The programme will estimate, from the tolerable gram level of the product, and its mass and size, suitable dimensions for the foam blocks. PE packaging tends to be hot wire cut from sheet and assembled into complex shapes using hot melt adhesives such as EVA. There have been more efforts to use blends such as Nova Chemicals' Arcel (an ethylene styrene interpolymer in bead form) to create a more durable foam than EPS. EPP can be moulded into complex shapes, with the steam bonding of the beads (291). These packaging foams compete with polyolefin film products such as Jiffy foam (bubblewrap) and macrobubbles made by heat sealing 150 mm lengths of tubular LDPE film. As it is difficult or costly to recycle such foam products, in some countries there is a move towards biodegradable starch foams and moulded paperboard. Efforts to model the deformation of EPP foam by FEA have been hampered by the lack of a sufficient range of data. Mills and Masso-Moreu (a.20) showed that simple pyramid methods, initially proposed by Stupak, are successful for the ribs on EPP mouldings. The ribs (Figure 13(a)) in the calculation taper from a base width of 100 mm to a top width in the range 15 to 70 mm, over a height H = 75 mm, with a length 75 mm. In the model the steps are to: 1. Divide the rib into 50 equal thickness layers of equal thickness, Δy

∑ ε Δy i

(19)

i

7. Plot Fj versus xj then repeat from step 3. Figure 13(b) shows the predicted force-deflection relationship, compared with the experimental impact data. For this simple product shape, the simple method is as good as FEA. However the errors are greater for 3-dimensional truncated pyramids, and the method cannot consider more complex shapes. FEA shows that the stresses are not constant across a layer of the rib; however a number of errors, caused by the approximations, must cancel. The author’s FEA (unpublished) shows that only the directly impacted portions of complex mouldings are under significant stress, so above approximate approach is justified.

6.2 EVA in Running Shoe Midsoles EVA foam dominates the sport shoe midsole market (61) (73) (155) (179) (267). The author’s chapter in Sports Materials (a.21) gives more details. The reasons for the selection of EVA foams are related to the durability of the foam and its ability to cushion tens of thousands of impacts, in which the compressive stress reaches about 500 kPa, and the compressive strain can be 60%. The reasons for the use of the relatively high densities, in the range 150 to 250 kg m-3 are related to the long-term performance. Nevertheless the EVA densities are lower than those of PU foams for the same application, giving a significant weight advantage. In the industry the foam may be selected by use of a

21

Polyolefin Foams

Figure 13(a) The shape of a packaging foam rib

Figure 13(b) Comparison of experimental and predicted force versus crush distance for ribs, of EPP foam of density 43 kg m-3, having varying top half widths in mm (a.20)

compression set test, which has been found to relate to the multi-impact response. Research (a.18) suggests that there is no air loss from the foam, but a gradual deterioration in the cell walls after repeated bending. Dubois (76) described the use of crosslinked blends of PE and ESI in shoes. In blends with EVA, there is an improvement in the 23 °C compression set value; alternatively a softer foam with greater resiliency can be obtained with the same compression set compared with EVA.

22

6.3 Body Armour Equestrian chest protectors (a.22) are designed for impact energies of about 50 J, however the large-radius, spherical anvil used is not a biofidelic model of the chest. At least 20 mm of foam, of initial yield stress about 0.5 MPa, are needed to meet the BETA standard from 1995. LDPE foams were used at that stage of density around 70 kg m-3 and were segmented into approximately 50 by 50 mm blocks, sewn to a garment, to allow the body to change shape (261). With the

Polyolefin Foams

change to higher impact energies in BS EN 13158: 2000 tests (a.23), the segmented LDPE foams have been replaced by curved slabs of foamed PVC/vinyl rubber blends, which are denser and have a greater compressive resistance. Other types of sports protection, such as cricketer’s leg pads, still use PE and EVA foams. Even the ballistic armour used by police forces and armies, requires the use of foam backing. Otherwise, when the ceramic slab or Kevlar fibre pack, stops the bullet/fragment, there is a blunt impact on the chest.

6.4 Helmets The load spreading efficiency of EPP foam, used in some bicycle helmets, is better than that of polystyrene foam, because it does not crack around indentations (a.24). Load spreading, for a blow on a convex object, will lessen the risk of skull fracture, and bring more of the helmet foam into play in an impact. The design of a helmet for a particular impact velocity, to keep the linear acceleration of the head below a level (circa 200 g) where brain injury is likely, requires the use of a foam of a specified compressive yield stress (a.25). For a given level of compressive yield stress, the density required of EPP foam is greater than that of EPS, since the yield stress of PP is lower than that of PS. EPS is notoriously prone to crack, since it has a very low tensile strength, and there are flaws where beads have not completely fused together – a network of channels at the bead boundaries are necessary to keep the cycle time reasonable. The fact that EPP recovers better from an impact means that EPP is preferred to EPS for multi-impact helmets (279) (301). Helmets for sports such as canoeing or cricket tend to have less severe impact requirements than for bicycle helmets, so may use smaller amounts of LDPE or EVA foam. As ventilation is important, there may be large holes in the foam and in the helmet shell. Rugby headgear uses LDPE foam. The International Rugby Board rules state that the LDPE foam density does not exceed 45 kg m-3, and its thickness does not exceed 12 mm. The aim seems to be to prevent the headgear being used as an aggressive weapon towards other players. Consequently there is limited protection, if there is a head-to head clash with another player.

6.5 Soccer Shin Protectors

density of the EVA foam was 45 kg m-3 or less, to prevent discomfort when worn against the leg muscle. They were evaluated against a kick from a studded boot. The shells need to have a high bending stiffness, to spread the highly localised load from a stud. However many shells had only a low bending stiffness, which meant that the soft EVA foam bottomed out, causing very high pressures on the leg, which would probably cause bruising. Both FEA and experimental impacts were used with high-speed photography to show that the shells could buckle locally under a stud impact. The best guards use complex shaped shells to increase the transverse bending stiffness.

6.6 Automotive Headliners in cars (22) (38) (64) may use PP Strandfoam, which has the advantage over EPP of having a near-constant compressive yield stress over the strain range from 10% to 70%, rather than a stress that can rise by a factor of two over that range. All vehicles manufactured after September 2002 must meet FMVSS 201U (a.27) in which a free-flying headform impacts upper interior components such as the roof rail at 6.7 m s-1, in this test, carried out at 23 °C, the Head Injury Criterion (HIC) must not exceed 1000. The HIC is an average of the headform linear acceleration raised to the 2.5th power. Given the limited space for protective foam in the roof area, Strandfoam allows the use of thinner padding than EPS to meet the specification. However, one disadvantage of PP foam is its greater temperature sensitivity than the rival polyurethane foam products. Since the operational temperature range for cars is from –40 to 120 °C this places a severe constraint on the choice of a suitable system. If tests were introduced over a range of temperatures, EPP would probably be replaced by other materials. EPP foam inserts for bumpers (fenders) are a major application area (91) (98) (161) (279) (302) (362) (366) (386) (398) (424). Unlike EPS, EPP has the multiimpact performance required, can fit inside the hollow bumper beam, and has a low mass. ABAQUS FEA has been used (a.28) to design such inserts. A range of crosssectional shapes were considered in an attempt to achieve a near uniform crushing load of about 3 kN over a deflection of 50 mm. Those with triangular cut outs were found to be best.

The construction of football shin guards (a.26) is a curved outer shell over layer(s) of EVA foam. The

23

Polyolefin Foams

7 Market Growth Harden’s (27) market survey of the growth of polyolefin foams production and sales shows that 114 x 106 kg of PE was used to make PE foam in 2001. The growth rate for the next 6 years was predicted as 5-6% per year, due to recovery in the US economy and to penetration of the automotive sector. In North America, 50% of the demand was for uncrosslinked foam, 24% for crosslinked PE foams, 15% for EPP, 6% for PP foams, 3% for EVA foams and 2% for polyethylene bead (EPE) foam. As protective packaging is the largest PE foam use sector, PE foam competes with a number of other packaging materials. Substitution of bead foam products (EPP, EPE, ARCEL copolymer) by extruded non-crosslinked PE foams, produced by the metallocene process was expected on the grounds of reduced costs. Compared with EPS foams the polyolefin foams have a lower yield stress for a given density. Compared with PU foams, the upper use temperature of polyolefin foams tends to be lower. For both these reasons, these foams are likely to coexist.

a.7

M.O. Kristen, Metallocenes, Emerging Technology – New and Advanced Materials, on www.sun.ac.za/unesco/polyED2000/ conf1999/lectures1999/kristen.pdf.

a.8

K. Blizard, J. Anderson and A. Schroder in Proceedings of Automotive Elastomers Conference, Dearborn, MI, USA, 2003.

a.9

R. Verdejo, Gas Loss and Durability of EVA Foams Used in Running Shoes, University of Birmingham, UK, 2003. [Ph.D. Thesis]

a.10

C.-T. Yang, K.L. Lee and S.-T. Lee, Journal of Cellular Plastics, 2002, 38, 113.

a.11

C.-T. Yang and S.-T. Lee, Journal of Cellular Plastics, 2003, 39, 59.

a.12

N.P. Suh in Microcellular Plastics, Ed., J.L. Stevenson, Carl Hanser, Munich, Germany, 1996, Chapter 3.

a.13

L.J. Gibson and M.F. Ashby, Cellular Solids, 2nd Edition, Cambridge University Press, 1998.

a.14

A.M. Kraynik, MK Neilsen, D.A. Reinelt and W.E. Warren in Foams and Emulsions, Eds., J.F. Sadok and N. Rivier, Kluwer, 1999, p.259286.

a.15

N.J. Mills and H. Zhu, Journal of Mechanics and Physics of Solids, 1999, 47, 669.

a.16

A.E. Simone and L.J. Gibson, Acta Materialia, 1998, 46, 3929.

a.17

O. Almanza, Y. Masso-Moreu, N.J. Mills, M.A. Rodríguez-Pérez, Thermal expansion coefficient of polyethylene foams – theory and experiments, Journal of Polymer Science and Physics, 2004, accepted.

a.18

R. Verdejo and N.J. Mills, Simulating the effect of long distance running on shoe midsole foam, Polymer Testing, 2004, accepted.

a.19

Dow ‘Ethacalc Millennium’ program, w w w. d o w. c o m / p e r ff o a m / i n f o / d e s i g n / auth.htm.

a.20

Y. Masso-Moreu and N.J. Mills in Proceedings of the 13th APRI Conference on Packaging, WorldPak 2002, CRC Press, Ed., D. Twede, p.797-815.

a.21

N.J. Mills in Sport Materials, Ed., M.J. Jenkins, Woodhead, Cambridge, UK, 2003, Chapter 4, p.65-99.

Acknowledgements I gratefully acknowledge the contributions of my coworker Adam Gilchrist and PhD students, in particular Raquel Verdejo and Yago Masso-Moreu.

Additional References a.1

Y. Masso-Moreu and N.J. Mills, Rapid hydrostatic testing of rigid polymer foams, Polymer Testing, 2004, accepted.

a.2

C.J. Benning, Journal of Cellular Plastics, 1967, 3, 62.

a.3

C.J. Benning, Journal of Cellular Plastics, 1967, 3, 125.

a.4

C.J. Benning, Journal of Cellular Plastics, 1967, 3, 174.

a.5

R.E. Skochdopole and L.C. Rubens, Journal of Cellular Plastics, 1965, 1, 91.

a.6.

A. Nauta, Stabilisation of Low Density, Closed Cell Polyethylene Foam, University of Twente, Netherlands, 2000 (www.ub.utwente.nl/ webdocs/ct/1/t000001c.pdf). [Ph.D. Thesis]

24

Polyolefin Foams

a.22

N.J. Mills and S. Ankrah in Proceedings of Designing Equipment for Body Protection: I Mech E Conference, London, UK, 2002 Paper No. 1.

a.23

BSEN 13158, Protective Clothing – Protective Jackets, Body and Shoulder Protectors for Horse Riders – Requirements and Test Methods, 2000.

a.24

A. Gilchrist and N.J. Mills, Accident Analysis and Prevention, 1996, 28, 525.

a.25

N.J. Mills in Sport Materials, Ed., M.J. Jenkins, Woodhead, Cambridge, UK, 2003, Chapter 2, p.9-46.

a.26

S. Ankrah and N.J. Mills, Performance of football shin guards for direct stud impacts, Sports Engineering, 2004, accepted.

a.27

FMVSS 201 U, Occupant Protection in Interior Impact, 1998.

a.28

G. Frederick, G.A. Kaepp, C.M. Kudelko, P.J. Schuster, F. Domas, U.G. Haardt and W. Lenz, SAE Transactions, 1995, 104, Section 5, 394.

25

Polyolefin Foams

Acronyms and Abbreviations BETA

British Equestrian Trade Association

CFC

chlorofluorocarbon

DMTA

dynamic mechanical thermal analysis

EPDM

ethylene propylene diene monomer

EPE

polyethylene bead

EPP

expanded polystyrene

ESI

ethylene-styrene interpolymer

EVA

ethylene vinyl acetate

FEA

finite element analysis

HCFC

hydrochlorofluorocarbon

HDPE

high-density polyethylene

HIC

head injury criterion

HMS

high melt strength

LDPE

low-density polyethylene

LLDPE

linear low-density polyethylene

MWD

molecular weight distribution

PE

polyethylene

POE

polyolefin

POP

polyolefin plastomers

PP

polypropylene

PPO

polyphenylene oxide

PU

polyurethane

PVC

polyvinyl chloride

SEM

scanning electron microscope

SS

steryl steramide

STP

standard temperature and pressure

Tg

glass transition temperature

TPV

thermoplastic vulcanisates

26

References and Abstracts

Abstracts from the Polymer Library Database Item 1 Blowing Agents and Foaming Processes 2003. Proceedings of a conference held Munich, Germany, 19th-20th May 2003. Shawbury, Rapra Technology Ltd., 2003, Paper 20, p.203-7, 29 cm, 012 DENSITY AND OPEN CELL EFFECTS ON PE FOAM MODULUS Kolli M; Lee S-T Sealed Air Corp. (Rapra Technology Ltd.) Compressive modulus of various PE foam boards, in different densities and open cell content, are measured and compared with different models. Contributory elements to compressive resistance are investigated. Agreement between test results and modelling improves significantly while only considering the struts strength parallel to compressive force. 7 refs. USA

Accession no.895010

FOAM EXTRUSION OF POLYPROPYLENE FOAMS - NEW DEVELOPMENTS AND APPPLICATIONS Kropp I D Polymer-Tec GmbH (Rapra Technology Ltd.) In the food packaging and the automotive industry a strong tendency to use thermoplastic foams can be seen. Especially in the automotive industry, more sophisticated safety and convenience technology is installed which is why other automotive parts have to become lighter in weight. Up-and-coming environmental issues concerning the recycling of a car after its use lead to the increased utilisation of standard polymers such as PP. Consequently PP foams, in combination with decorative films and textiles, will have a bright future. Some applications and new tendencies in the automotive area, as well as in the food packaging area, are described. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.895004 Item 2 Blowing Agents and Foaming Processes 2003. Proceedings of a conference held Munich, Germany, 19th-20th May 2003. Shawbury, Rapra Technology Ltd., 2003, Paper 17, p.169-78, 29 cm, 012 EFFECT OF NUCLEATING AGENTS ON POLYPROPYLENE FOAM MORPHOLOGY Rodrigue D; Gosselin R Laval,Universite; CERSIM (Rapra Technology Ltd.) Calcium carbonate and talc of different particle sizes are used to determine the effect of concentration and nucleating agent type on the morphology of high density PP foam produced by extrusion. As expected, increasing the particle concentration and/or decreasing particle size improves the structure of the foams: higher cell density and lower cell sizes. Furthermore, it is found that talc is more effective than calcium carbonate at keeping all other parameters constant. This indicates the importance and selection complexity of nucleating agent type and characteristics for design purposes. 19 refs. CANADA

Item 4 Offshore 63, No.7, July 2003, p.84-5 MULTI-LAYER POLYPROPYLENE SYSTEM IMPROVES THERMAL PERFORMANCE AND DURABILITY Borealis Business Unit Pipe has responded to the growing need in deepwater for foam structure and stiffness in pipe coatings with its multilayer PP system. Borealis has developed a new generation of PP materials that balance stiffness, toughness and thermal performance. In the fivelayer system, the steel pipe is coated with epoxy, adhesive, PP, foam and mechanical/outer protection. The multilayer system has already been proven in water depths to 1,000m. For deeper water depths to 2,000m, the company looked to using two types of foam, creating an optimised multilayer structure. In that design, the steel pipe is coated with epoxy, adhesive, solid PP, less aerated foam that can withstand higher temperatures, more solid PP, foam with more air for lower temperatures, and outer protection. BOREALIS EUROPEAN UNION; SCANDINAVIA; SWEDEN; WESTERN EUROPE

Accession no.895007

Accession no.894288

Item 3 Blowing Agents and Foaming Processes 2003. Proceedings of a conference held Munich, Germany, 19th-20th May 2003. Shawbury, Rapra Technology Ltd., 2003, Paper 14, p.147-53, 29 cm, 012

Item 5 Advances in Polymer Technology 22, No.3, Fall 2003, p.209-17 BINARY BLENDS OF EVA AND METALLOCENE-CATALYZED ETHYLENEALPHA-OLEFIN COPOLYMERS AND THEIR

© Copyright 2004 Rapra Technology Limited

27

References and Abstracts

FILM PROPERTIES Kontopoulou M; Huang L C; Lee J A Kingston,Queen’s University Blends of ethylene-vinyl acetate (EVA) copolymer with metallocene-catalysed elastomeric ethylene-alpha-olefin copolymer were investigated and were found to be immiscible in the melt and solid state but mechanically compatible. The morphology (SEM), thermal (DSC), rheological (viscosity), mechanical (including tensile, shear thinning and elastic behaviour) and optical properties of EVA-rich and ethylene-alpha-olefin copolymer-rich blends were studied and the results are discussed in terms of processibility in film applications. 24 refs. CANADA

Accession no.894238 Item 6 Polymer Testing 22, No.6, 2003, p.705-9 STUDY OF SHEAR NUCLEATION THEORY IN CONTINUOUS MICROCELLULAR FOAM EXTRUSION Guo M C; Peng Y C South China,University of Technology A theoretical analysis based on shear energy was carried out with the aim of illustrating the mechanism of shear nucleation through a slit channel die in continuous microcellular foam extrusion. The shear energies for different positions and for different experimental conditions were calculated to demonstrate the various contributions to the surface free energy required for bubble nucleation. 14 refs. CHINA

Accession no.893140 Item 7 Journal of Cellular Plastics 39, No.2, March 2003, p.117-32 EFFECT OF VISCOSITY ON LOW DENSITY FOAMING OF POLY(ETHYLENE-CO-OCTENE) RESINS Gendron R; Vachon C Canada,National Research Council Foaming of low density ethylene-octene copolymer resins by injection moulding is the result of various reactions occurring during the process. This includes simultaneous decomposition of the chemical blowing agent and crosslinking of the polymer matrix during curing in the mould, followed by foaming after mould opening. Dynamic rheology, as well as elongational viscosity, are investigated for compounds prepared from resins with different melt indices and various crosslinking agent levels, and these results are linked to the morphology and density of the corresponding foams. Rheological

28

requirements are finally defined quantitatively for this set of conditions. 9 refs. CANADA

Accession no.892799 Item 8 Polymer Composites 24, No.3, June 2003, p.304-13 TAILORING VISCOELASTIC AND MECHANICAL PROPERTIES OF THE FOAMED BLENDS OF EVA AND VARIOUS ETHYLENESTYRENE INTERPOLYMERS Liu I-C; Tsiang R C-C Taiwan,National Chung Cheng University Foams were prepared from blends of EVA and ethylenestyrene interpolymers having styrene contents ranging from 30 to 73 wt.% and Tgs ranging from -2 to 33C, in the presence of various amounts of dicumyl peroxide and their viscoelastic and mechanical properties investigated. The effects of styrene content and peroxide concentration on the morphology, degree of crosslinking and expansion ratio of the foams were assessed as was the influence of the type of ethylene-styrene interpolymer on the Tg of the foams. It was found that the Tg of the blends could be tailored by selection of the appropriate interpolymer. 19 refs. TAIWAN

Accession no.892124 Item 9 Rubber World 228, No.2, May 2003, p.31-2 EPDMS FOR AUTOMOTIVE SPONGE PRODUCTS Tredinnick D W Crompton/Uniroyal Chemical This article is concerned with the selection of EPDM polymers for producing continuous cured sponge extrusions for automotive type applications. The first part of the discussion will address identifying the key polymer properties that are necessary to select the polymer type for a given application. This is then contrasted with the polymer selection process according to a new technology. This new technology represents a new generation of EPDM that provides optimised performance characteristics accomplished by controlled compositional distribution. This technology involves both the catalyst system and manufacturing process. USA

Accession no.889649 Item 10 Journal of Applied Polymer Science 88, No.14, 28th June 2003, p3139-50 FOAM EXTRUSION OF HIGH DENSITY POLYETHYLENE/WOOD-FLOUR

© Copyright 2004 Rapra Technology Limited

References and Abstracts

COMPOSITES USING CHEMICAL FOAMING AGENTS Qingxiu Li; Matuana L M Michigan,Technological University; Michigan,State University The effects of different types and forms of foaming agents with, and without, coupling agents on the cell morphology of extrusion foamed high density polyethylene (HDPE) and HDPE/woodflour composites were examined using density measurements and scanning electron microscopy. Effect of foaming agent type was found to be minimal, but the use of coupling agents in composite foams was found necessary to achieve high void fractions. 29 refs. USA

Accession no.888866 Item 11 Polymer Preprints. Volume 43. Number 2. Fall 2002. Papers presented at the ACS Meeting held Boston, Ma., 18th-22nd Aug.2002. Washington, DC, ACS, Div.of Polymer Chemistry, 2002, p.1234-5, 28cm, 012 PROPERTIES OF FOAMING WATERSWELLABLE EPDM RUBBER Xiaohong Sun; Qiang Shi; Guo Zhang Jilin,University (ACS,Div.of Polymer Chemistry) Foaming water-swellable EPDM rubber was prepared using multi-component mechanical blending technology. The cell properties, the mechanical properties and the water-swelling abilities resulting from these properties were investigated. The mechanical properties were found to decrease with increasing foaming agent content. Incorporation of silica made the TS of the water-swellable rubber(WSR) increase 2 to 6 fold compared with that of unfoamed WSR before immersing in water. For silicafilled EPDM WSR, the mechanical properties of unfoamed WSR decreased, while that of foaming WSR increased. In contrast with traditional WSR, foaming WSR improved volume water-swelling ratio 2 to 6 fold and accelerated water-absorbing rate. In the presence of silica, the water-absorbing rate was improved and waterswelling equilibrium time was significantly reduced. 5 refs. CHINA

Accession no.888075 Item 12 Journal of Applied Polymer Science 88, No.12, 20th June 2003, p.2842-50 MICROCELLULAR FOAM OF POLYMER BLENDS OF HDPE/PP AND THEIR COMPOSITES WITH WOOD FIBER Rachtanapun P; Selke S E M; Matuana L M Michigan,State University

© Copyright 2004 Rapra Technology Limited

Microcellular foams of polymer blends of high-density polyethylene (HDPE) and polypropylene (PP), and composites with wood fibre, were investigated to determine the effects of processing conditions, blend composition, and wood fibre content on the crystallinity, sorption behaviour of carbon dioxide, void fraction and cell morphology of the materials. It was found by DSC that blending decreased the crystallinity of HDPE and PP and facilitated microcellular foam production. The void fraction was shown to be strongly dependent on processing conditions and blend composition. The addition of wood fibre inhibited microcellular foaming. 20 refs. USA

Accession no.886248 Item 13 Journal of Cellular Plastics 39, No.1, Jan. 2003, p.29-47 SIMPLE MODELLING OF THE MECHANICAL PROPERTIES WITH PART WEIGHT REDUCTION FOR MICROCELLULAR FOAM PLASTIC Xu J; Kishbaugh L Trexel Inc. Replacement of solid polymers by microcellular polymers may lead to a 10 percent or higher reduction in material without significantly affecting the properties of the moulded part. A model that treats a microcellular foam part made by injection moulding as a sandwich structure in which a uniform low-density foamed core is encased by a skin frame is presented. Predictions of changes in mechanical properties such as tensile strength, flexural strength and impact strength for filled and unfilled polycarbonate materials at different levels of weight reduction are calculated based on this model and are compared with those found in practice. Based on the results recommended weight reductions are discussed in terms of specific mechanical properties. 13 refs. USA

Accession no.886222 Item 14 Cellular Polymers 22, No.1, 2003, p.43-56 EFFECT OF COMPOUND FORMULATION AND PROCESSING CONDITIONS ON PROPERTIES OF EXTRUDED EPDM AND NR/EPDM FOAMS Lewis C; Rodlum Y; Misaen B; Changchum S; Sims G L A Prince of Songkla University; Manchester,University; UMIST The effects of compound formulations and processing conditions on the structure and properties of extruded EPDM and NR/EPDM blends of tube foams were studied. The characteristics of blends of blowing agents (azodicarbonamide (ADC)/dinitrosopentamethylenetriamine

29

References and Abstracts

(DNPT)) were studied using a gas evolution apparatus. The decomposition temperature of ADC decreased with both DNPT and 4,4-oxybis(benzenesulphonyl hydrazide) (OBSH) blending and this affected the structure and properties of the resulting foams. Using a tube mould for an extrudate to vulcanise the NR/EPDM extrudate in a hot air oven was found to control the expansion and foam dimensions. The NR compositions affected the foam structure and properties. 16 refs.

content of the post-crosslinked foams increased with increase in the irradiation dose, beam intensity and irradiation temp. and with the crosslinking coagent content. Experimental studies indicated that beam intensity was the most important parameter with regard to gel content homogeneity. Noticeable changes in mechanical properties, e.g. TS, tear strength, compressive strength and hardness, were also observed. An experimental study was also conducted by the manufacture of low-density open-cell foam. 15 refs.

EUROPEAN COMMUNITY; EUROPEAN UNION; THAILAND; UK; WESTERN EUROPE

KOREA

Accession no.883684

Accession no.877944

Item 15 Polymer Engineering and Science 43, No.1, Jan.2003, p.40-54 IMPORTANCE OF TIMELY POLYMER SINTERING WHILE PROCESSING POLYPROPYLENE FOAMS IN ROTATIONAL MOLDING Pop-Iliev R; Rizvi G M; Park C B Toronto,University

Item 17 Journal of Cellular Plastics 38, No.5, Sept.2002, p.421-40 FOAM EXTRUSION OF PP-EMA REACTIVE BLENDS Pesneau I; Champagne M; Gendron R; Huneault M Canada,National Research Council

The morphology of PP foams obtained by processing PP pellets that had been pre-compounded with a chemical blowing agent was shown to be controllable either by pellet sintering or cell coalescence. The viscosity of the basic PP resin and the processing temperature determined which of these two key factors had the greater influence on the foaming process. The desired volume expansion ratio of the foam also played an important role as it determined the formulation of the foamable resin and the shot size. Desirable PP foam structures in compounding based rotational foam moulding could be obtained only if pellet sintering took place prior to the decomposition of the blowing agent and if the processing temperature during the foaming process was kept lower than the temperature of cell coalescence. 22 refs. CANADA

Accession no.881036 Item 16 Journal of Cellular Plastics 38, No.6, Nov.2002, p.471-96 ELECTRON BEAM IRRADIATION OF NONCROSSLINKED LDPE-EVA FOAM Kim D W; Kim K S Chungbuk,National University LDPE and EVA were blended in a 80/20 ratio and the non-crosslinked foam thereof was exposed to various doses of electron beam irradiation in air. The foam was made using isobutane as blowing agent. It was found that foam with uniform cell structure was not achieved in the case of pre-crosslinked foam with more than 40% gel fraction. Non-crosslinked foams were, however, easily crosslinked to a gel content of about 57% with electron beam irradiation under optimum conditions. The gel

30

A study was carried out into the foaming of PP/ethylenemethyl acrylate copolymer thermoplastic elastomers with carbon dioxide during dynamic crosslinking. The gel content, density and cell and blend morphologies were determined and the relationship therebetween investigated. The solubility of carbon dioxide in the polymers was measured and the influence of the blowing agent on blend morphology assessed. It was found that gel content determined blend morphology and blend morphology influenced foam morphology and foam density. 24 refs. (ANTEC 2001, Dallas, Texas, 6-10 May) CANADA

Accession no.877286 Item 18 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper 358, Session T25Applied Rheology, Extrusion I, Thermoplastic Materials and Foams. Interactive Presentations, pp.5, CD-ROM, 012 EFFECT OF MOLECULAR WEIGHT ON MECHANICAL AND MORPHOLOGICAL PROPERTIES OF HIGH DENSITY POLYETHYLENE FOAMS Zhang Y; Ait-Kadi A; Rodrigue D Laval,University (SPE) The shear and elongational rheology of four linear high density polyethylenes, with different molecular weights and melt indices, was studied. Foams were produced from the polymers using 1-3 wt% azodicarbonamide (ACA) as the chemical blowing agent, and characterised by morphological studies and measurement of tensile properties. The cell size decreased with increasing

© Copyright 2004 Rapra Technology Limited

References and Abstracts

molecular weight. The cell size of the lower molecular weight polymers increased with increasing ACA content, whilst the reverse was true for the higher molecular weight polymers. The lower molecular weight polymers were brittle, whilst the higher molecular weight materials were ductile and tough. 9 refs. CANADA

Accession no.876448 Item 19 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper 353, Session T25Applied Rheology, Extrusion I, Thermoplastic Materials and Foams. Interactive Presentations, pp.5, CD-ROM, 012 STUDY OF THE FOAMING PROCESS OF POLYETHYLENE WITH HIGH PRESSURE CO2 IN A MODIFIED EXTRUSION SYSTEM Garcia-Leiner M; Lesser A J Massachusetts,University (SPE) The barrel of a single screw extruder was modified to permit carbon dioxide injection, and the feed section modified to enable control of the polymer:carbon dioxide ratio. High density (HDPE) and low density polyethylenes (LDPE) were extruded and the extrudate morphology studied by scanning electron microscopy. The influence of extrudate morphology on thermal properties was determined by differential scanning calorimetry. Decreasing the die temperature to the polymer melting point promoted cell nucleation. Increasing the saturation pressure increased cell nucleation, so that samples processed at high pressures had higher cell densities and reduced cell sizes. Foaming was promoted by increasing the time of polymer exposure to carbon dioxide prior to extrusion, attributed to the dependence of cell nucleation on the mount of dissolved gas. Dissolution of carbon dioxide in LDPE at higher temperatures restricted foaming and resulted in gas bubbles on the extrudate surface. The thermal properties of HDPE were not modified by foaming, attributed to the high crystallisation rate. 16 refs.

This morphology was compared with that of the extruded LDPE, which was used to produce the foams. The main source of the differences between the morphologies of the two types of material appeared to be the geometrical arrangement of the polymer in thin cell walls and the complicated mechanical and thermal history of the polymer that comprised the cell foams of the foams. 22 refs. (European Conference on Macromolecular Physics: Morphology and Properties of Crystalline Polymers, Eger, Hungary, Sept.2001) EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.875539 Item 21 Polymer Engineering and Science 42, No.9, Sept.2002, p.1907-18 FOAM PROCESSING AND CELLULAR STRUCTURE OF POLYPROPYLENE/CLAY NANOCOMPOSITES Pham Hoai Nam; Maiti P; Okamoto M; Kotaka T; Nakayama T; Takada M; Ohshima M; Usuki A; Hasegawa N; Okamoto H Toyota Technological Institute; Kyoto,University; Toyota Central R & D Laboratories Inc. PP/clay nanocomposites(PPCNs) were autoclave-foamed in a batch process. Foaming was performed using supercritical carbon dioxide at 10 MPa, within the temp. range 130.6 to 143.4C, i.e. below the m.p. of either PPCNs or maleic anhydride(MA)-modified PP matrix without clay. The foamed PP-MA and PPCN2 (prepared at 130.6C and containing 2 wt % clay) showed closed cell structures with pentagonal and/or hexagonal faces, while foams of PPCN4 and PPCN7.5 (prepared at 143.4C, 4 and 7.5 wt % clay) had spherical cells. SEM confirmed that foamed PPCNs had high cell density of 10,000,000 to 100,000,000 cells/mL, cell sizes in the range of 30 to 120 micrometres, cell wall thicknesses of 5 to 15 micrometres and low densities of 0.05 to 0.3 g/mol. TEM observations of the cell structure showed biaxial flow-induced alignment of clay particles along the cell boundary. The correlation between foam structure and rheological properties of the PPCNs is also discussed. 15 refs.

USA

JAPAN

Accession no.876443

Accession no.873198

Item 20 Journal of Macromolecular Science B B41, No.4-6, 2002, p.761-75 MORPHOLOGY OF SEMICRYSTALLINE FOAMS BASED ON POLYETHYLENE Rodriguez-Perez M A; de Saja J A Valladolid,Universidad The matrix polymer morphology of a collection of LDPE foams manufactured from a high-pressure nitrogen solution process was analysed at different length scales.

© Copyright 2004 Rapra Technology Limited

Item 22 SPE Automotive TPO Global Conference 2002. Proceedings of a conference held Dearborn, Mi., 30th Sept-2nd Oct.2002. Brookfield, Ct., SPE, 2002, Interior Applications Session, p.97-117, 27cm, 012 SIMPLIFIED HIGH EFFICIENCY POLYPROPYLENE FOAM PART DESIGNS FOR AUTOMOTIVE HEADLINER COUNTERMEASURE APPLICATIONS

31

References and Abstracts

Maurer M; Tusim M; Lemmon J; Williams S Dow Chemical Co.; DaimlerChrysler Corp. (SPE,Detroit Section) On August 18, 1995 the National Highway Traffic and Safety Administration (NHTSA) invoked Federal Motor Vehicle Safety Standard (FMVSS) 201U to provide protection when an occupant’s head strikes upper interior components such as side rails, front headers and the roof during a crash. Subject to the phase-in requirements of FMVSS 201U, all vehicles manufactured after September 1, 2002 will be required to satisfy the head injury criteria (HIC) requirements of FMVSS 201U. Automotive OEMs are now equipping upper interior components such as headliners with foam, structural thermoplastic components or structural composite countermeasures to manage energy during simulated head impact crash tests. For most small, midsize and luxury car platforms, automotive OEMs are now offering optional features such as powered sunroofs and integrated air bag curtains on most coupe and sedan models. With these options available on most passenger cars today, as many as eight discrete headliners may need to be designed. The challenge facing automotive OEMs lies in using unique energy absorbing (EA) countermeasure designs with a common headliner substrate surface without increasing the cost or investment while maintaining optimal head Impact performance. It is discussed how high efficiency PP foam headliner countermeasure part designs can be simplified without the need for costly tooling associated with injection moulded ribbed cartridges, moulded PU foams and steam chest moulded expanded bead foam parts. An advanced component-level headliner countermeasure test methodology is discussed, in addition to the statistical analysis of such tests performed with EA countermeasures. 8 refs. USA

Accession no.872078 Item 23 Advances in Materials and Processes in Rotomolding. Proceedings of a conference held Independence, Ohio, 9th-11th June 2002. Brookfield, Ct., 2002, Session II, p.79-84, 27cm, 012 ROTATIONAL MOULDING V THE MECHANICS OF FOAMING Throne J Sherwood Technologies Inc. (SPE,Rotational Molding Div.; SPE,Cleveland Section) The motivation for foaming is weight reduction without loss in stiffness. In addition, PE does not seem to suffer the same dramatic decrease in impact as other plastics do when foamed. This is fortunate for rotational moulders, since it is the primary material of choice. Although polymers have been foamed via injection moulding and extrusion for decades, foaming in rotational moulding is a relatively new feature. Making bubbles go away during

32

processing of unfoamed polymers is very difficult. Making bubbles appear, then retaining them during processing of foamed polymers, is also very difficult. The problem is that the general rotational moulding process in many ways acts counter to the characteristics needed to produce controlled fine-celled bubble growth. To achieve quality foams, the rotational moulder must realise the limitations of the rotational moulding process. The problems faced in trying to achieve quality foam products are detailed. Some ways to mitigate some of these problems are also proposed. 18 refs. USA

Accession no.872067 Item 24 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session VII, p.153-62, 27cm, 012 CRITICAL PROCESSING TEMPERATURE IN MANUFACTURE OF FINE-CELLED PLASTIC/ WOOD-FIBRE COMPOSITE FOAMS Guo G; Rizvi G M; Park C B; Lin W S Toronto,University (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) The main benefits of incorporating wood fibres (WF) in plastics are increased stiffness and lowered cost of the resultant composites. However, these improvements are usually accompanied by reduction in the ductility and impact resistance. These shortcomings can be removed by effectively foaming and incorporating a fine-celled structure in these composites. The volatiles released from WF during processing are known to deteriorate the cell structure. The maximum processing temperature, which affects the amount of volatiles released by the WF, during extrusion of fine-celled plastic/WF composite affects the cell morphology. A study is undertaken to identify the critical temperature above which the cellular structure of WF composite foams is significantly deteriorated. To clearly identify the effects of the volatiles generated from WF on the cellular morphology, neither chemical blowing agent nor physical blowing agent is used in the foam processing. The experimental results show that regardless of the drying method, the highest processing temperature of plastic/WF composites should be minimised, preferably below 170 deg.C, in order to avoid the adverse effects of the volatiles generated from the WF during processing. A method of estimating the emissions from WF during extrusion processing by using TGA data is also proposed. 30 refs. CANADA

Accession no.871808 Item 25 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002.

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Brookfield, Ct., 2002, Session VI, p.141-51, 27cm, 012 VISUAL OBSERVATIONS OF BATCH AND CONTINUOUS FOAMING PROCESS Taki K; Yatsuzuka T; Nakayama T; Ohshima M Kyoto,University (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) Visual observations of batch and continuous physical foaming processes are conducted to understand the bubble nucleation and bubble growth behaviours in polymers. Batch foaming is performed using a newly developed highpressure cell, where two sapphire windows are equipped on the walls so as to observe the early stage of bubble nucleation and growth behaviours with a help of CCD and microscope. In the batch process, homo PP is foamed at different pressure release rate and at different foaming temperature using CO2 as a physical blowing agent to see the effects of operating condition on the bubble nucleation and growth rate. The in situ observation can identify that: the bubble nucleation and growth occur simultaneously; the influence region, where the nucleation is suppressed, exists around bubbles; and the nucleation rate and the growth rate increase as the pressure release rate increases. Furthermore, the continuous foaming is also performed using a different visualisation unit, which consists of an autoclave and extrusion slit-die with quartz windows. It is found that the nucleation mechanism in the continuous foaming, i.e. extrusion foaming, is different from that of batch foaming. In continuous extrusion foaming, the nucleation can be induced flow and/or shear stress, and the bubbles are also generated by cavitations brought about by the surface roughness of the wall. 13 refs. JAPAN

Accession no.871807 Item 26 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session VI, p.133-9, 27cm, 012 FUNDAMENTAL FOAMING MACHANISMS GOVERNING VOLUME EXPANSION OF EXTRUDED PP FOAMS Naguib H E; Park C B; Yoon E; Reichelt N Toronto,University; Borealis GmbH (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) The fundamental foaming mechanisms governing the volume expansion behaviour of extruded PP foams are described. Careful analysis of extended experimental results indicates that the final volume expansion ratio of the extruded PP foams blown with butane is governed by either loss of blowing agent or crystallisation of polymer matrix. A CCD camera is installed at the die exit to carefully monitor the shape of the extruded PP foam. The CCD images are analysed to illustrate both these mechanisms of gas loss and crystallisation during foaming

© Copyright 2004 Rapra Technology Limited

at various temperatures, and it is observed that the maximum expansion ratio is achieved when the governing mechanism is changed from one to the other. In general, the gas loss mode is dominant at high temperatures, whereas the crystallisation mode is dominant at low temperatures. When the gas loss mode is dominant, the volume expansion ratio is increased by decreasing the temperature because of the reduced amount of gas lost. By contrast, when the crystallisation mode is dominant, the expansion ratio is increased by increasing the temperature because of the delayed solidification of polymer. The processing window variation with the butane concentration, the change of the temperature ranges for the two governing modes, and the sensitivity of melt temperature variations to the volume expansion ratio are discussed in detail, based on obtained experimental results for both branched and linear PP materials. 38 refs. AUSTRIA; CANADA; EUROPEAN UNION; WESTERN EUROPE

Accession no.871806 Item 27 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session IV, p.103-12, 27cm, 012 POLYETHYLENE FOAM RESIN OUTLOOK Harden W Nova Chemicals Inc. (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) An overview is provided of the North American PE Foam Market. Historical market growth rate and market dynamics are presented as well as a forecast to 2007. An analysis is also presented of the forces that impact PE foam demand and pricing based upon Michael Porter’s well-known five-market forces model for analysing industries and markets. Application of this model will provide some insight into dynamics that should be considered in creating a robust business plan. 3 refs. USA

Accession no.871802 Item 28 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session II, p.47-54, 27cm, 012 SEQUENTIAL REACTIVE BLENDING/ FOAMING OF PET IN EXTRUSION EQUIPMENT Zhang Q; Dhavalikar R; Wan C; Dey S K; Xanthos M New Jersey,Institute of Technology (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) Single- and twin-screw extruders with customised screw profiles are used to produce low density PETP-PP foams in the presence of reactive compatibiliser and coagents. Low density PETP foam is also produced from

33

References and Abstracts

commercially available PETP by chemical modification/ chain extension to enhance the foamability followed by addition of physical blowing agent down stream. The process conditions, assumed reactions and product characteristics are given in detail. 7 refs. USA

Accession no.871797 Item 29 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session I, p.19-24, 27cm, 012 BATCH AND CONTINUOUS FOAMING OF BLENDS OF LLDPE AND CROSS-LINKED LDPE Zhang Q; Dey S K; Xanthos M New Jersey,Institute of Technology (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) Blends of LLDPE and crosslinked LLDPE (xLDPE) are foamed by a proprietary batch foaming process as well as in a continuous tandem extrusion line. Good quality, low-density foams are produced from both foaming processes. For batch foaming, it is found that high concentration of xLDPE is necessary to bring up the LLDPE resin properties to foamable levels. In extrusion foaming, adding 10% crosslinked LDPE results in significant improvements in foam processing and foam quality. 5 refs. USA

wider range of foaming agents are available under the trademark Inspire. 1 ref. USA

Accession no.871794 Item 31 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session I, p.1-8. 27cm, 012 LOW DENSITY EXTRUDED POLYPROPYLENE FOAMS - ONE OF THE FINAL FRONTIERS? Folland R; Reichelt N; Stadlbauer M Borealis Polymers NV; Borealis GmbH (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) The processing behaviour of Daploy WB130HMS PP foam resin is described. This material offers new opportunities for low density PP foam production. Densities down to 50 kg/cub.m and below can be achieved with physical foaming. The final foam properties can be tailored by blending WB130HMS with the full range of standard PP grades or metallocene PEs (m-PE). A recycling study, using physical foaming with butane, shows that Daploy WB130HMS can be reprocessed without any significant effects on foam density and structure. 14 refs. AUSTRIA; BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN EUROPE

Accession no.871793

Accession no.871795 Item 30 Foams 2002. Proceedings of a conference held Houston, Tx., 22nd-23rd Oct.2002. Brookfield, Ct., 2002, Session I, p.9-18, 27cm, 012 NOVEL HIGH MELT STRENGTH POLYMERS FOR FOAM APPLICATIONS Mispreuve H; Chaudhary B I; Thoen J Dow Chemical Co. (SPE,Thermoplastic Materials & Foams Div.; SPE,South Texas Section) Inspire High Melt Strength (HMS) Performance Polymers are innovative differentiated propylene-based polymers offering a combination of high melt strength and high impact strength, which is particularly useful for foam applications. The flexural modulus of typical Inspire HMS Performance Polymers ranges from about 150,000 to about 300,000 psi. The characteristics of Inspire Performance Polymers are described, as well as the soft and flexible foams made by expanding these polymers using isobutane as blowing agent. Applications include thermal and acoustic insulation, food packaging, automotive and cushion packaging applications. These results are to be considered as a feasibility study for a design space. Fine-tuned products for foaming using a

34

Item 32 Polymer Preprints, Volume 41, Number 1, Proceedings of a conference held San Francisco, Ca., March 2000.. Washington D.C., ACS,Div.of Polymer Chemistry, 2000, p.1058-9, 28cm, 012 FOAMING OF POLYETHYLENE IN A NOVEL DYNAMIC DECOMPRESSION AND COOLING PROCESS Song K; Apfel R E Yale,University (ACS,Div.of Polymer Chemistry) Details are given of the fabrication of foams with uniform closed-cell structures. LDPE was used as polymer feedstock. Thermal analysis was performed using DSC and morphologies were examined using SEM. 12 refs. USA

Accession no.870857 Item 33 Cellular Polymers 21, No.4, 2002, p.237-64 ETHYLENE-STYRENE INTERPOLYMER FOAM BLENDS: MECHANICAL PROPERTIES AND SPORT APPLICATIONS Ankrah S; Verdejo R; Mills N J

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Birmingham,University Foamed blends of ethylene-styrene interpolymer and LDPE were subjected to a range of mechanical tests, including compressive impact testing, Instron compression and Poisson’s ratio measurements, compressive creep measurements and compression set and recovery measurements. The data obtained were compared with those for EVA and the suitability of these foamed blends as replacements for EVA in the manufacture of soccer shin guards and midsoles for sports shoes was evaluated. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.870425

Pop-Iliev R; Park C B Toronto,University (SPE) The single step rotational moulding of polyethylene with an outer dense skin and an inner foamed core was investigated. The non-foamable component was a blend of ethylene polymers with different particle sizes and melt indices, whilst the foamable phase was linear low density polyethylene containing a chemical blowing agent with an operating temperature range of 149-177 C. The formation of the desired structure required the formation of the skin layer prior to activation of the blowing agent, and this was achieved by use of a suitable processing timetemperature profile. 25 refs. CANADA

Item 34 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper 192, Session M38Rotational Molding Materials, pp.5, CD-ROM, 012 INVESTIGATION OF THE PROCESSING CHARACTERISTICS AND MECHANICAL PROPERTIES OF METALLOCENE POLYETHYLENE FOAMS FOR ROTATIONAL MOULDING Archer E; Harkin-Jones E; Kearns M P; Fatnes A-M Belfast,Queen’s University; Borealis AS (SPE) The rheological and thermal properties, and the rotational blow moulding of foamed metallocene (mPE) and ZieglerNatta polyethylenes were compared. Several commercial chemical blowing agents were used. The moulded polymers were characterised by flexural and impact testing, and by density and bubble content measurements. The foamed mPE had higher impact resistance than the conventional PE. However, the mPE exhibited lower flexural properties, attributed to the smaller and more uniform bubble size. The average bubble size in both polymers increased with increasing oven temperature. The nitrogen-releasing blowing agents, which were exothermic, gave lower density foams than the carbon dioxide-releasing, endothermic agents. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NORWAY; SCANDINAVIA; UK; WESTERN EUROPE

Accession no.868458 Item 35 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper 191, Session M38Rotational Molding Materials, pp.5, CD-ROM, 012 SINGLE-STEP ROTATIONAL FOAM MOLDING OF SKIN-SURROUNDED POLYETHYLENE FOAMS

© Copyright 2004 Rapra Technology Limited

Accession no.868457 Item 36 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper 159, Session M32Thermoplastic Materials and Foams. Thermoplastic Foams, pp.5, CD-ROM, 012 EFFECT OF VISCOSITY ON LOW DENSITY FOAMING OF POLY(ETHYLENE-CO-OCTENE) RESINS Vachon C; Gendron R Canada,National Research Council (SPE) Poly(ethylene-co-octene) copolymers with differing melt flow indices, crosslinked using dicumyl peroxide (DCP), were characterised by dynamic rheology and elongational viscosity studies. The properties of injection moulded foams prepared using 0-2.54 wt% DCP and azodicarbonamide blowing agent were evaluated in relation to the polymer rheological properties. It was concluded that to obtain a good foam required a balance between polymer viscosity and branching, and also that crosslinking is required to maintain expansion and to prevent collapse. 7 refs. CANADA

Accession no.868425 Item 37 Modern Plastics International 32, No.10, Oct.2002, p.61 PROTECTIVE FOAM LINERS ARE NATURALLY BREATHABLE Toensmeier P A Impact-resistant foam liners used in helmets and other protective gear are usually not breathable unless air passages are fabricated in them. Brock USA has developed a process for moulding closed-cell foam that permits three-dimensional air flow and moisture evaporation

35

References and Abstracts

through impact liners. The foam structure is also claimed to upgrade impact resistance. Brock liners are moulded of a PP compound that is supplied as CO2-expanded beads, 3 to 6mm in diameter. Key to the process is application of an elastomeric adhesive coating that makes beads adhere to each other at points along their surfaces where they come in contact. This creates air passages between the beads throughout the liner. The technique of adhering spheres to each other rather than fusing them together permits a range of densities in one protective liner. BROCK USA

main mechanisms that influenced each property and the foam microstructure were examined in an attempt to explain the results. A theoretical model was used to examine the thermal conductivity values. The results showed the extent to which reducing the cell size could improve the insulating capabilities of these materials. The effect of cell size on the mechanical properties at low strain rates was very small, so the thermal expansion did not depend on cell size. The structural characteristics, however, influenced the dynamic mechanical response at temps. below 15C. 25 refs.

USA

EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; UK; WESTERN EUROPE

Accession no.868167

Accession no.865897

Item 38 Machine Design 74, No.16, 22nd Aug.2002, p.64/8 FOAM MEETS VEHICLE CRASHWORTHINESS REGS HEAD ON Maurer M J; Tusim M H Dow Chemical Co.

Item 40 Polymer International 51, No.7, July 2002, p.601-6 PHYSICAL STUDIES OF FOAMED REINFORCED RUBBER COMPOSITES. PART I. MECHANICAL PROPERTIES OF FOAMED ETHYLENE-PROPYLENE-DIENE TERPOLYMER AND NITRILE-BUTADIENE RUBBER COMPOSITES El Lawindy A M Y; Abd El-Kade K M; Mahnoud W E; Hassan H H Suez Canal,University; Cairo,University

The US NHTSA Federal Motor Vehicle Safety Standard 201U requires that passenger cars, trucks and vans, in a crash, protect an occupant’s head in the event it strikes upper interior parts including side rails, front headers and the roof. Conventional foams such as EPP bead and recoverable PU absorb impact energy through compression of cellular structures and then rebound, along with the occupant, which is an undesirable feature. Rigid thermoplastics more efficiently dissipate energy by fracturing or buckling, but do not cushion blows as well as foams. A new high-efficiency PP honeycomb foam from Dow Automotive combines properties of both materials. To speed design with the PP foam, Dow used a statistical design of experiments with a six-factor BoxBehnken response surface design. USA

Furnace black-reinforced EPDM and NBR blends were compounded with different concentrations of azodicarbonamide foaming agent to produce EPDM and NBR foamed composites. All the mechanical parameters measured were found to decrease as the foaming agent concentration and/or temperature increased. The stressstrain results were discussed with reference to the continuum mechanics theory for compressible materials. 16 refs. EGYPT

Accession no.862957

Accession no.868107 Item 39 Cellular Polymers 21, No.3, 2002, p.165-94 EFFECT OF CELL SIZE ON THE PHYSICAL PROPERTIES OF CROSSLINKED CLOSED CELL POLYETHYLENE FOAMS PRODUCED BY A HIGH PRESSURE NITROGEN SOLUTION PROCESS Rodriguez-Perez M A; Gonzalez-Pena J I; Witten N; de Saja J A Valladolid,Universidad; Zotefoams PLC The thermal conductivity, thermal expansion, mechanical properties at low strain rates and dynamic mechanical properties of a collection of crosslinked closed cell PE foams manufactured by a high pressure nitrogen solution process were studied as a function of the cell size. The

36

Item 41 Machine Design 74, No.15, 8th Aug.2002, p.52 PADDING THAT COOLS AND PROTECTS It is briefly reported that designers at Brock USA use expanded PP beads in their lacrosse jerseys. The beads, marketed under the name Arpo by JSP International, provide impact protection and cooling. When a player wearing a Brock jersey is struck on the chest, each bead moves, trying to move adjacent beads, thus deflecting energy away from the body and dissipating it over a larger surface area. BROCK USA USA

Accession no.862704

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 42 Polymer Engineering and Science 42, No.7, July 2002, p.1481-92 STRATEGIES FOR ACHIEVING ULTRA LOWDENSITY POLYPROPYLENE FOAMS Naguib H E; Park C B; Panzer U; Reichelt N Toronto,University; Borealis GmbH An investigation was carried out on the volume expansion behaviour of foams made from various propylene polymers with the aim of producing extruded PP foams with a large volume expansion ratio. The effects of processing conditions on volume expansion and cell density and of the amount of blowing agent (butane) on volume expansion were examined and the foamability of branched and linear PPs was compared. It was found that ultra low-density, fine-celled PP foam with a very high expansion ratio could be produced from branched PP because of its reduced degree of cell coalescence. 46 refs. AUSTRIA; CANADA; EUROPEAN UNION; WESTERN EUROPE

Accession no.862223 Item 43 Polymer Engineering and Science 42, No.6, June 2002, p.1274-85 DEFORMATION AND ENERGY ABSORPTION CHARACTERISTICS OF MICROCELLULAR ETHYLENE-OCTENE COPOLYMER VULCANIZATES Nayak N C; Tripathy D K Indian Institute of Technology The compressive stress-strain properties of unfilled and filled, closed-cell, microcellular ethylene-octene copolymer vulcanisates were investigated in relation to various blowing agent loadings and strain rates. Fillers employed were calcium carbonate, silica and aluminium silicate. A correlation was established between the compression modulus and density of the foams and the efficiency and ideality parameter plotted against stress to determine the maximum efficiency and ideality region, which would make these foams suitable for cushioning and packaging applications. 36 refs. INDIA

Accession no.859239 Item 44 Macromolecular Symposia Vol.181, 2002, p.507-11 FOAMED CROSSLINKED LDPE/PP BLENDS MADE BY HOT MOLD INJECTION MOLDING Kotzev G; Touleshkov N; Christova D Bulgarian Academy of Sciences Details are given of the mechanical properties and melting/crystallisation behaviour of foamed and crosslinked LDPE/PP blends made by hot mould injection moulding. The chemical changes as a result of the

© Copyright 2004 Rapra Technology Limited

crosslinking were determined by gel content. Thermal properties were studied using DSC. The difference of influence of crosslinking agent on the chemical changes of both polymers was established. 7 refs. BULGARIA; EASTERN EUROPE

Accession no.856864 Item 45 Macromolecular Symposia Vol.181, 2002, p.421-6 SITE-RESOLVED X-RAY SCATTERING STUDIES. II. THE MORPHOLOGY IN INJECTION-MOLDED PP FOAMS Zipper P; Djoumaliisky S Graz,Universitat; Bulgarian Academy of Sciences PP-structural foam mouldings were produced on an injection moulding machine in a pre-pressurised mould cavity by the classical low-pressure process and an alternative low-pressure process. Melt temperature, injection direction and sprue diameter were varied. Crosssections cut from the middle of the small cylinder in longitudenal orientation were investigated by siteresolved X-ray scattering. Morphological properties were investigated. 4 refs. AUSTRIA; BULGARIA; EASTERN EUROPE; EUROPEAN UNION; WESTERN EUROPE

Accession no.856854 Item 46 Materials in Telecommunications (incorporating PIT IX). Proceedings of a conference held London, 26th27th September 2001. London, Institute of Materials, 2001, Paper 28, pp5, 012 DEVELOPMENT OF AN HDPE COMPOUND FOR INSULATION OF COMMUNICATION CABLES BY THE GAS INJECTION PROCESS Kerr E A; Keane P D Wire & Cable Technical Service (Institute of Materials) As part of the drive to increased performance in communication cables (telephony, data and coaxial cables), continued advances have been made in extrusion and material technology. One of the most significant over the last decade is the advent of physical foaming. Insulation foaming leads to lower cable attenuation and permits higher data transmission by use of broader bandwidth signals. Traditional foaming by a chemical expansion agent is now supplemented by gas injection or physical foaming. The principal advantages of this technology include: higher foaming ratios and lower, intrinsic losses of the dielectric material, in comparison to chemical expansion. Due to the specific demands of the gas injection process, specially formulated compounds have been developed. The development of a fully formulated HDPE compound is described. Such a

37

References and Abstracts

compound is designed for use in a broad range of coaxial and data cable applications. 1 ref. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.855855 Item 47 Blowing Agents and Foaming Processes 2002. Proceedings of a conference held Heidelberg, 27th-28th May 2002. Shawbury, Rapra Technology Ltd., 2002, Paper 23, p.243-50, 29cm, 012 MELT STRENGTH ANALYSIS FOR EXTRUDED POLYOLEFIN FOAM DEVELOPMENT Yang C-T; Lee S-T Sealed Air Corp. (Rapra Technology Ltd.) The results are reported of an investigation into the melt rheology of LDPE blown with isobutane in elongational flow using roller pull-off experiments and the effect of blending an ionomer with LDPE on the extrusion process and properties of the resulting foam. Extensional viscosity is calculated from the pulling force and roller speed. It is shown that the roller pull-off method is suitable for generating extensional viscosity data and that addition of ionomer gives rise to enhanced melt strength. 13 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Item 49 Blowing Agents and Foaming Processes 2002. Proceedings of a conference held Heidelberg, 27th-28th May 2002. Shawbury, Rapra Technology Ltd., 2002, Paper 14, p.141-54, 29cm, 012 THE USE OF POLYFUNCTIONAL MONOMERS IN COMPRESSION-MOULDED LOW-DENSITY POLYETHYLENE FOAM FORMULATIONS Sims G L A; Sipaut C S UMIST; Manchester,University; Sains Malaysia,University (Rapra Technology Ltd.) The influence of adding polyfunctional monomers having different structures and functionality into a dicumyl peroxide-based crosslinking system for LDPE was investigated. Monomers employed were diallyl phthalate, trimethylolpropane trimethacrylate and triallyl cyanurate. The effects of formulation on matrix gel content and on foam density at similar gel content were examined and the dependence of foam density on melt modulus assessed. The applicability of swell ratio for estimating foam density was evaluated and the suitability of triallyl cyanurate as a crosslinking promoter for LDPE foam demonstrated. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; MALAYSIA; UK; WESTERN EUROPE

Accession no.854598

Accession no.854606 Item 48 Blowing Agents and Foaming Processes 2002. Proceedings of a conference held Heidelberg, 27th-28th May 2002. Shawbury, Rapra Technology Ltd., 2002, Paper 20, p.213-26, 29cm, 012 EFFECT OF RECYCLING ON THE RHEOLOGICAL PROPERTIES AND FOAMING BEHAVIOURS OF BRANCHED POLYPROPYLENE Naguib H E; Mukhopadhyay A; Wang J; Park C B; Reichelt N Toronto,University; Borealis GmbH (Rapra Technology Ltd.) The rheological properties and foamability of recycled, branched PP foam and virgin PP foam were determined and compared. The rheological behaviour of the foams was correlated with foaming behaviour and foam morphology was investigated at various processing temperatures using a single-screw tandem foam extruder. The foam samples were characterised by volume expansion ratio and cell population density and the data obtained correlated with the rheological data. 17 refs. AUSTRIA; CANADA; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.854603

38

Item 50 Journal of Materials Science 37, No.7, 1st April 2002, p.1347-54 EFFECT OF ALUMINIUM SILICATE FILLER ON MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED CELL MICROCELLULAR ETHYLENE-OCTENE COPOLYMER Nayak N C; Tripathy D K Indian Institute of Technology SEM was used to study the effect of aluminium silicate filler on the morphology of Engage-8150 microcellular ethylene-octene copolymer, with variation of contents of blowing agent and silicate filler, in comparison with the unfilled vulcanisates. The average cell size, maximum cell size and cell density varied with variation of blowing agent and filler loading. Physical properties such as relative density, hardness, TS, EB, modulus, tear strength decreased with increasing blowing agent concentration, while TS, 100% modulus, tear energy and hardness varied linearly with the density of the filled vulcanisates. The elastic nature of closed cells reduced the hysteresis loss compared with solid compounds. Set properties improved with blowing agent concentration. It was observed that stress relaxation behaviour was independent of blowing agent concentration, i.e. density of closed cell microcellular vulcanisates. The flaw sizes were found

© Copyright 2004 Rapra Technology Limited

References and Abstracts

theoretically to be about 2.57 times larger than maximum cell sizes observed by SEM. 34 refs. DU PONT DOW ELASTOMERS INDIA

Accession no.853284 Item 51 Journal of Reinforced Plastics & Composites 21, No.2, 2002, p.101-20 MELT COMPOUNDING BASED ROTATIONAL FOAM MOLDING TECHNOLOGY FOR MANUFACTURE OF POLYPROPYLENE FOAMS Pop-Iliev R; Park C B Toronto,University Details are given of the processing of PP foams in rotational foam moulding. The method comprises dispersing a chemical blowing agent in the PP matrix using a twin screw compounder, pelletising the obtained expandable composition, and then producing foams in an uninterrupted rotational foam moulding cycle. Different foamable compositions were formulated in order to prepare both 3-fold and 6-fold foamable pellets from each PP grade. Cell morphologies are discussed. 19 refs. CANADA

Accession no.851704 Item 52 Journal of Cellular Plastics 38, No.2, March 2002, p.163-76 CELLULAR UHMW POLYETHYLENE PRODUCED BY NON-FOAMING LEACHING TECHNIQUE: MORPHOLOGY AND PROPERTIES Shutov F; Ananthanarayan V T Minnesota,University; Tennessee,Technological University A process comprising a combination of compression moulding technique and leaching was developed to produce open porous UHMW PE. The developed process did not require any design or machine modifications and, at the same time, was environmentally friendly. This repeatable process could produce samples having predetermined pore size, pore shape and porosity dictated by the size, shape and content of the salts in the moulding mixture. All the ingredients were approved by the FDA for in-vivo medical applications. A maximum porosity of 60% could be obtained, beyond which the mechanical properties of the material deteriorated. The porous UHMW PE developed, which was permeable by liquids, could be used as a substrate matrix in bone regeneration and in hip- and knee joint replacements. With adequate lubrication, the porous implants would prevent the formation of polymer debris due to friction and thereby increase the life of the biomedical implants. 12 refs.

Item 53 Journal of Applied Polymer Science 83, No.2, 10th Jan.2002, p.357-66 MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED CELL MICROCELLULAR ETHYLENE-OCTENE COPOLYMER: EFFECT OF PRECIPITATED SILICA FILLER AND BLOWING AGENT Nayak N C; Tripathy D K Indian Institute of Technology SEM photomicrographs were used to study the morphology of microcellular ethylene-octene copolymer and the effects of variation of blowing agent and silica filler loading were investigated. The average cell size, maximum cell size and cell density varies with variation of azodicarbonamide blowing agent and filler loading. Physical properties such as relative density, hardness, tensile strength, elongation at break, modulus and tear strength decrease with blowing agent concentration. Stress relaxation behaviour is independent of blowing agent loading. Set properties improve with blowing agent concentration, and the elastic nature of closed cells reduces the hysteresis loss compared to solid compounds. The hysteresis loss decreases with increasing blowing agent as well as filler loading. The tear path deviates from the linear front and gives rise to a larger effective depth of the flows. 33 refs. INDIA

Accession no.846621 Item 54 Cellular Polymers 20, No.6, 2001, p.403-16 EFFECT OF MATERIAL FACTORS ON THE DENSITY AND CELL MORPHOLOGY OF CHEMICALLY FOAMED POLYPROPYLENE Dixon D; Martin P J; Harkin-Jones E Belfast,Queen’s University The effects are assessed of various material factors on the cell morphology and density of extruded expanded PP rod samples, produced using a range of commercial chemical blowing agents. The work is part of a research project into the optimisation of the extrusion and subsequent thermoforming of EPP sheet for food packaging applications. Trials were also carried out to quantify the effects on the foam of additives, such as pigment, sodium benzoate, co-polymer, and regrind, and the grade of polymer used. A design of experiment methodology was adopted for these latter tests. 7 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.843854

USA

Accession no.850202

© Copyright 2004 Rapra Technology Limited

39

References and Abstracts

Item 55 Cellular Polymers 20, No.6, 2001, p.386-402 VISCOELASTIC BEHAVIOUR OF ALUMINIUM SILICATE FILLED CLOSED-CELL MICROCELLULAR ETHYLENE-OCTENE COPOLYMER VULCANIZATES: EFFECT OF BLOWING AGENT, TEMPERATURE, FREQUENCY AND STRAIN Nayak N C; Tripathy D K Indian Institute of Technology An investigation is reported of the dynamic mechanical response of aluminium silicate filled closed cell microcellular ethylene-octene copolymer (Engage) vulcanisates. The effect of blowing agent, frequency and temperature on dynamic mechanical properties is studied, and the strain-dependent dynamic mechanical properties of microcellular Engage are also investigated. 25 refs. INDIA

Accession no.843853 Item 56 Journal of Injection Molding Technology 5, No.3, Sept.2001, p.152-9 MICROCELLULAR FOAM PROCESSING IN RECIPROCATING-SCREW INJECTION MOLDING MACHINES Jingyi Xu; Pierick D Trexel Inc. A microcellular foam processing system for the reciprocating-screw injection moulding machine was developed. The design criteria derived provided the necessary conditions for creating and maintaining a single-phase solution in the overall system of the plasticising unit, supercritical fluid(SCF) delivery unit and hydraulic unit. An overall systems approach was the key to successful implementation of a microcellular foam process. These modifications are described, together with the component designs required for a microcellular foam moulding machine. The important components discussed are the plasticising unit, injection unit, hydraulic unit, clamp unit and SCF unit. The general guidelines for designing an injection moulding machine for microcellular foam are listed as the conclusions. 18 refs. USA

Accession no.840081 Item 57 Journal of Cellular Plastics 37, No.1, Jan. 2001, p.21-42 THERMAL CONDUCTIVITY OF A POLYETHYLENE FOAM BLOCK PRODUCED BY A COMPRESSION MOULDING PROCESS Martinez-Diez J A; Rodriguez-Perez M A; De Saja J A; Arcos y Rabago L O; Almanza O A

40

Valladolid,Universidad; Queretaro,Universidad Autonoma; Colombia,University Low density PE foam sheets having a thickness of 10 mm were cut from a block produced by compression moulding and their thermal conductivities over the temperature range from 24 to 50C determined. The evolution of the properties along the block was analysed and the cell structure, apparent mean cell diameter, anisotropy, mean cell wall thickness and relative fraction of polymer determined using quantitative image analysis and a previously reported model utilised to predict the thermal conductivity of the foams. 30 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.839328 Item 58 Adhasion Kleben & Dichten 45, No.7/8, 2001, p.29-32 German COMPRESSIVE LAMINATION OF PE FOAM WITH ACETATE TEXTILE FABRICS Krueger G Krueger & Partner PE foams are recommended because of their properties, especially for use in packaging. In medical technology they are also of interest because of their purity. In car construction we value their flexibility that is almost independent of temperature as well as the very low fogging effect. This study shows how the real strength of PE foams can be improved. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.839191 Item 59 Kunststoffe Plast Europe 91, No.11, Nov. 2001, p.24-7 MANY VARIATIONS Wolf M; Saenze J; Stopperka K Bruckner Maschinenbau GmbH A novel procedure, called LISIM (Linear Motor Simultaneous Stretching) technique, for the manufacture of expanded, biaxially oriented films of PP and propylene copolymers, is reported. Examples, which demonstrate the the range of possibilities for varying the final film properties through formulations, machine settings and processing are demonstrated and the mechanical and optical properties of expanded films made by the above technique tabulated. (Kunststoffe, 91, No.11, 2001, p.6873) EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.837216

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 60 Kobunshi Ronbunshu 58, No.9, 2001, p.486-8 Japanese COMPRESSION MODULUS OF OPEN-CELLED POLYETHYLENE FOAM Adachi H; Hasegawa T Nagoya Municipal Industrial Research Institute The static modulus and dynamic storage modulus were investigated for some open-celled PE foams by static compression tests and dynamic viscoelastic measurements in compression mode. Experimental data were compared with theoretical predictions. 8 refs. JAPAN

Accession no.836948 Item 61 Journal of Macromolecular Science B 40, No.3-4, 2001, p.603-13 STRUCTURE-PROPERTY RELATIONSHIPS IN POLYOLEFIN FOAMS Almanza O; Arcos y Rabago L O; Rodriguez-Perez M A; Gonzalez A; de Saja J A Colombia,University; Queretaro,Universidad Autonoma; Valladolid,Universidad Two theoretical models were developed for use in predicting the thermal conductivity and Young’s modulus of LDPE foams produced by a high-pressure nitrogen solution process. The main factors that influenced the properties of these materials were studied in terms of these models. The results showed that the two properties were dependent on different factors. The matrix polymer morphology of the foams was also studied and compared with that of the solid sheet from which the foams were manufactured. 14 refs. (Europhysics Conference on Structure Development during Polymer Processing: Physical Aspects, Sept.2000, Minho, Portugal) COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; MEXICO; SPAIN; WESTERN EUROPE

Accession no.836389 Item 62 Industria della Gomma 45, No.2, March 2001, p.45-7 Italian MACHINES FOR EVA AND CROSSLINKED FOAMS Details are given of the E266-4 injection press developed by Main Group for the production of shoe soles from EVA and crosslinked EVA foams. MAIN GROUP EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.835431

© Copyright 2004 Rapra Technology Limited

Item 63 Polyolefins 2001. Conference proceedings. Houston, Tx., 25th-28th Feb. 2001, p.431-40 MUCELL THERMOFORMABLE POLYOLEFIN FOAM SHEET Blizard K; Chapman B Trexel Inc. (SPE,South Texas Section; SPE,Thermoplastic Materials & Foams Div.; SPE,Polymer Modifiers & Additives Div.) An overview is presented of Trexel’s MuCell microcellular foam extrusion technology and a description is given of its application to the manufacture of thermoformable PP sheet. The results of pilot scale thermoforming trials carried out to optimise forming conditions and obtain data about potential cycle time effects, measurements of the densities, flexural modulus and wall thicknesses of the sheets and containers made from the sheets and cell structure analysis are presented and discussed. USA

Accession no.834931 Item 64 Polyolefins 2001. Conference proceedings. Houston, Tx., 25th-28th Feb. 2001, p.323-34 HIGH EFFICIENCY STRUCTURAL OLEFINIC FOAM FOR AUTOMOTIVE ENERGY ABSORBING (EA) COUNTERMEASURE APPLICATIONS Maurer M J; Tusim M H; Cate P Dow Chemical Co. (SPE,South Texas Section; SPE,Thermoplastic Materials & Foams Div.; SPE,Polymer Modifiers & Additives Div.) The unique performance advantages of a new structural polyolefin foam, which is being used in commercial vehicle production for enhanced automotive safety performance, are described. This structural foam consists of a blend of high melt strength PP and blowing agent and and is being evaluated in a range of energy absorbing countermeasure applications, including pillar countermeasures for occupant head impact protection, headliner countermeasures for occupant head impact protection and front and rear end system countermeasures for vehicle chassis protection. 7 refs. USA

Accession no.834922 Item 65 Cellular Polymers 20, No.4, 2001, p.255-77 CROSSLINKING OF POLYOLEFIN FOAMS. I. EFFECT OF TRIALLYL CYANURATE ON DICUMYL PEROXIDE CROSSLINKING OF LOW-DENSITY POLYETHYLENE

41

References and Abstracts

Sims G L A; Sipaut C S UMIST; Manchester,University; Sains Malaysia,University The results are reported of a study of the dicumyl peroxide (DCP) crosslinking of two LDPEs having similar numberaverage molec.wts. but different molecular weight distribution and of the effect of triallyl cyanurate (TAC) on the crosslinking of these polymers. The effects of a) MWD on gel content, b) DCP concentration on gel content using a fixed concentration of TAC, c) TAC concentration on gel content using a fixed concentration of DCP, d) varying DCP concentration on melt behaviour, e) crosslinking systems containing TAC on melt behaviour, f) increasing DCP concentration on foam density and cell size for traditional crosslinking systems and g) TAC on foaming behaviour are discussed. 23 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; MALAYSIA; UK; WESTERN EUROPE

Accession no.832727 Item 66 Journal of Polymer Science: Polymer Physics Edition 39, No.18, 15th Sept.2001, p.2159-67 RHEOLOGICAL PROPERTIES AND FOAM PROCESSABILITY FOR BLENDS OF LINEAR AND CROSSLINKED POLYETHYLENES Yamaguchi M; Susuki K-I Tosoh Corp. The effect of blending crosslinked LLDPE (cLLDPE) on the rheological properties and foam processability of LLDPE is studied. A small addition of cLLDPE which has a low density of crosslink points, enhances strain hardening behaviour in the elongational viscosity to a great degree, although it has little effect on steady-state shear viscosity. The enhanced strain hardening reduces heterogeneous deformation during foaming. As a result, a foam with a uniform cell size distribution is obtained. 37 refs. JAPAN

Accession no.831171 Item 67 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 661 HEAT TRANSFER IN FOAM PLASTICS Pugne D; Mitchell M Pennsylvania,State University (SPE) The thermal conductivity of a section of a commercially produced high density polyethylene foam channel was measured. The walls consisted of a 6.4 mm foam core with a skin of 1.6 mm thickness on either side. Squares were machined from the outer surface of the channel, so that heat flow through: the entire thickness; the core plus one skin layer; and the complete section could be

42

measured. The ends of the channel were sealed and it was filled with water and ice. The outer surface temperature was measured as a function of time. The channel was then re-filled with water at 45.3 C and the surface temperatures again measured. Heat flow simulations were performed using finite element analysis software and the experimentally determined thermal conductivities. USA

Accession no.830093 Item 68 Foams 2000: Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p.149-61 CHALLENGE TO THE PRODUCTION OF LOW DENSITY PROPYLENE FOAMS IN EXTRUSION Naguib H E; Park C B Toronto,University (SPE) The volume expansion behaviour of low-density propylene foams in extrusion is investigated. As the escape of blowing agent from the foam causes the foam to contract and to have low expansion, efforts are made to prevent the gas loss during foaming. The basic strategies taken for this purpose are to use a branched propylene resin with high melt strength, to use a longchain blowing agent with low diffusivity, to employ glycerol monostearate as a diffusion retarder and to uniformly lower melt temperature. Use of a branched propylene resin is required to achieve large volume expansion because cell coalescence will expedite the gas loss from the extruded foam to the environment. The foam morphologies of linear and branched propylene materials at various processing temperatures are studied using a single-screw tandem foam extrusion system and their volume expansion behaviours compared. Ultra lowdensity, fine-celled propylene foams with very high expansion ratio up to 90-fold are successfully produced from the branched propylene resins. 25 refs. CANADA

Accession no.829222 Item 69 Foams 2000: Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p.139-48 USING POLYMER CHARACTERISATION TECHNIQUES TO PREDICT LDPE RESIN SUITABILITY FOR EXTRUDED FOAM APPLICATIONS Auger J; Nguyen L Nova Chemicals Corp. (SPE) All LDPE resins are not created equal. It is well known that autoclave LDPEs are considered to be the products

© Copyright 2004 Rapra Technology Limited

References and Abstracts

of choice for extrusion coating applications. On the other hand, LDPE resins produced using tubular reactors have a different structure, making them more suitable for extruded foam applications. More specifically, within the choices of tubular LDPE resins for extruded foam applications, some are easier to process and produce better quality foam products than others. The general chemical and rheological differences between autoclave and tubular LDPE resins are discussed, with emphasis on those differences for a variety of tubular LDPE products used in the extruded foam market. 4 refs. USA

Accession no.829221 Item 70 Foams 2000: Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p.108-16 BLENDING LLDPE MADE USING ADVANCED SCLAIRTECH TECHNOLOGY WITH NOVAPOL LDPE TO IMPROVE TEAR AND IMPACT PROPERTIES IN THIN FOAM SHEET Nguyen L; Ho K; Montgomery S Nova Chemicals Corp. (SPE) Improving tear properties in thin PE foam sheet applications has always been a challenge for many PE foam producers. A study of a blending LLDPE made using Advanced Sclairtech with Novapol LDPE is presented. Advanced Sclairtech technology is an improved solution polymerisation process using a new Ziegler-Natta catalyst. Blending LLDPE with LDPE is shown to improve the physical properties of thin foam sheets, particularly, tear and impact properties. The results of rheological characterisation and how it affects processing and physical and mechanical properties of blown film and foam sheet applications are discussed. The correlation of structure/ property relationship between resin, blown film and foam characteristics at various blend ratios is examined. 2 refs.

morphology, product applications and physical properties of ESI blend foams. 1 ref. USA

Accession no.829216 Item 72 Foams 2000: Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p.5-11 NEW DEVELOPMENTS IN INSPIRE PERFORMANCE POLYMERS FOR FOAMS Thoen J; Zhao J; Ansems P; Hughes K; Madenjian L; Sammler R; Suh K Dow Chemical Co. (SPE) A new generation of high melt strength (HMS) PPs, together with their applications in the field of foam extrusion, is discussed. The combination of high melt strength and high drawability of the polymer melt are the main characteristics of the new HMS Inspire Performance Polymers for foams. Applying advanced molecular architecture design capabilities derived from Insite technology, has resulted in high performance PP resins that are characterised by this desired rheological behaviour. Characteristic properties of the resins are presented, followed by a discussion of the benefits HMS Inspire Performance Polymers offer regarding polymer processing and final foam properties. It is now possible to manufacture PP foams with densities down to 25 kg/ cub.m, applying foam extrusion technologies traditionally designed for PE and PS. The main applications for the new lightweight foams are, for instance, in automotive energy absorption as well as in thermal and acoustic insulation applications. This new family of Inspire Performance Polymers extends the applicability of PP into a variety of new applications and markets, leveraging both existing and new extrusion technology capabilities. 5 refs. USA

Accession no.829207

USA

Accession no.829217 Item 71 Foams 2000: Second International Conference on Thermoplastic Foam. Conference proceedings. Parsippany, N.J., 24th-25th October 2000, p.102-7 NEW PRODUCTS MADE FROM ETHYLENESTYRENE INTERPOLYMER/LDPE BLEND FOAMS FOR VARIOUS APPLICATIONS Ramesh N S Sealed Air Corp. (SPE) Ethylene-styrene interpolymers (ESI) exhibit some interesting properties when they are blended with LLDPE or PP. Aspects covered include foaming technology, blend

© Copyright 2004 Rapra Technology Limited

Item 73 Revista de Plasticos Modernos 80, No.534, Dec.2000, p.630/7 Spanish CROSSLINKED EXPANDED MATERIALS: TECHNOLOGICAL DEVELOPMENTS AND PRODUCT OPPORTUNITIES The use of crosslinked expanded EVA and other crosslinked foamed polymers in shoe soles is discussed, and developments by Main Group in injection moulding machines for the production of soles from such materials are examined. MAIN GROUP SPA EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.828651

43

References and Abstracts

Item 74 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 460 DEVELOPMENT OF AN EXTRUSION SYSTEM FOR FINE-CELLED FOAMING OF WOODFIBER COMPOSITES USING A PHYSICAL BLOWING AGENT Zhang H; Rizvi G M; Lin W S; Guo G; Park C B Toronto,University (SPE) The use of wood fibre filler, combined with a cellular structure, to reduce cost and increase the mechanical properties of thermoplastics was investigated. An extrusion system was developed for material preparation, consisting of two extruders working in tandem. In the first extruder the plastic and wood fibre were compounded, moisture being vented in vapour form at the junction between the two extruders. In the second extruder the dry material was blended with a physical blowing agent, passed through a static mixer, then homogeneously cooled to enhanced melt strength, before extrusion through a nucleation die with cooling to freeze the surface layer of the extrudate. Trials were conducted using high density polyethylene, softwood fibre (50% less than 125 micrometre, with an addition of 0-40 wt%), modified polyethylene coupling agent, CO2 physical blowing agent (0-4 wt%) and talc as the nucleating agent. The system operated successfully, attributed to the combination of uniform mixing, improved bonding and effective moisture removal. The cell morphology was dependent upon the system configuration, and was strongly influenced by the coupling agent. Increasing the CO2 content had little effect on the cell morphology, but increased the volume expansion ratio and decreased the minimum foaming temperature. Reducing the fibre content enhanced the cell morphology. 58 refs.

measurements, and structure evaluation, considering cell size, density and elongation. Foam quality was improved by the use of branched PP, which gave thicknesses of up to 2 mm, and densities as low as 140 kg/cu m. A thickness of only 0.8 mm, and a density of 330 kg/cu m was achieved using linear PP. 3 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.827071 Item 76 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 443 USE OF ETHYLENE/STYRENE INTERPOLYMERS IN CROSSLINKED FOAMS FOR THE FOOTWEAR INDUSTRY Dubois R; Karande S; Wright D P; Martinez F Dow Chemical Co. (SPE) Foams of ethylene-styrene interpolymers (ESI), of crosslinked ethylene-vinyl acetate (EVA) copolymer, and of blends of these two copolymers, were prepared and evaluated for footwear applications. Prepared foams were characterised by measurement of: density; rebound resilience according to ASTM D 3574-86; Asker C hardness; compression set; oven shrinkage, at a temperature of 70 C for 1 h; and split tear. It was concluded that the blends could provide lower compression set, higher rebound resilience and greater softness without loss of split tear or heat shrinkage properties or gain in strength; or alternatively, the blends could provide lower weight, softer foams and higher rebound resilience with no loss of compression set, split tear, or heat shrinkage properties. 17 refs. Accession no.827070

CANADA

Accession no.827190 Item 75 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 444 INFLUENCING THE FOAM STRUCTURE OF CO2-BLOWN POLYPROPYLENE SHEETS Heinz R; Michaeli W Aachen,Institut fur Kunststoffverarbeitung (SPE) Polypropylene (PP) foam sheet was produced by foam extrusion using conventional linear PP and also a branched high melt strength PP, foamed using CO2 with either sodium bicarbonate/citric acid mixtures or talc as nucleating agents. The influences of: die gap; blowing agent content; nucleating agent content; temperatures of the cooling section, the static mixer, the die, and the die lip on the foam quality were evaluated. The foam quality was determined by density, thickness and surface quality

44

Item 77 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 442 FOAM EXTRUSION OF SYNDIOTACTIC POLYPROPYLENE-POLYETHYLENE BLENDS Park C P Dow Chemical Co. (SPE) Foams were extruded from low density polyethylene (LDPE) and blends of LDPE with syndiotactic polypropylene (sPP), using isobutane as the blowing agent. The extruded materials were characterised by measurement of dimensional stability at room temperature, density, tensile properties, dynamic stiffness, and crystallinity determined by differential scanning calorimetry. The sPP, with a slow crystallisation rate, did not interfere with the expansion of the LDPE, and enhanced the temperature resistance by in-situ crystallisation. The blends were flexible, dimensionally

© Copyright 2004 Rapra Technology Limited

References and Abstracts

stable, and were considered suitable for thermoforming applications. Accession no.827069

the melting temperature nor the crystallinity of PETP, but did decrease the crystallisation temperature. 5 refs. USA

Accession no.826616 Item 78 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 438 EFFECTS OF BLENDING OF BRANCHED AND LINEAR POLYPROPYLENE MATERIALS ON THE FOAMABILITY Naguib H E; Xu J X; Park C B; Hesse A; Panzer U; Reichelt N Toronto,University; Borealis GmbH (SPE) A tandem screw extruder arrangement feeding a gear pump was used for the foam extrusion of blends of linear and branched polypropylene (PP), with 0.8 wt% talc as the cell nucleating agent, to investigate the influence of blend composition on the processability and foam properties. The blowing agent was 10 wt% n-butane. The cell morphology was studied using optical and scanning electron microscopy. The cell density and the volume expansion increased with increasing proportion of branched PP, attributed to a reduction in cell coalescence due to the higher melt strength and extensibility of the branched material. The optimum temperature at which the volume expansion ratio occurred decreased with increasing branched content. This was attributed to the higher viscosity of the linear PP and to the extensional characteristics of the branched PP. The crystallisation temperature of the blends was not composition dependent, and it is proposed that the crystallisation temperature was not the determining factor for the maximum volume expansion ratio. 39 refs. AUSTRIA; CANADA; EUROPEAN UNION; WESTERN EUROPE

Accession no.827065 Item 79 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 400 EXTRUSION FOAMING OF PET/PP BLENDS Wan C; Xanthos M; Dey S; Zhang Q New Jersey,Institute of Technology (SPE) Blends of poly(ethylene terephthalate) (PETP) and polypropylene (PP) with different rheological properties were dry blended or compounded, and extrusion foamed using both physical blowing and chemical agents, and the foam properties compared with those of foam produced from the individual components in the absence of compatibilisers and rheology modifiers. The foams were characterised by measurement of density, cell size and thermal properties. Low density foam with a fine cell size was obtained by addition of a compatibiliser and a co-agent, and foamed using carbon dioxide. The presence of PP or a polyolefin-based compatibiliser did not effect

© Copyright 2004 Rapra Technology Limited

Item 80 BLOWING AGENTS AND FOAMING PROCESSES CONFERENCE 2001. Proceedings from a conference held Frankfurt, 13th-14th March 2001. Shawbury, Rapra Technology Ltd., 2001, Paper 28. 012 FOAMING OF FILM AND SHEET FROM POLYPROPYLENE AND POLYSTYRENE Berghaus U Reifenhauser GmbH (Rapra Technology Ltd.) The production of foamed films and sheets from polypropylene and polystyrene is discussed, with particular reference to packaging applications. Advantages of foamed materials for this application are examined, and the chemical and physical foaming processes are described. Extrusion technology for film and sheet by chemical and physical foaming processes is discussed, and recent developments in the coextrusion of multilayer packaging trays for the food industry are considered. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; UK; WESTERN EUROPE

Accession no.826304 Item 81 BLOWING AGENTS AND FOAMING PROCESSES CONFERENCE 2001. Proceedings from a conference held Frankfurt, 13th-14th March 2001. Shawbury, Rapra Technology Ltd., 2001, Paper 7. 012 STRATEGIES FOR ACHIEVING FINE-CELLED LOW-DENSITY POLYPROPYLENE FOAMS Naguib H E; Park C B; Hesse A; Panzer U; Reichelt N Toronto,University (Rapra Technology Ltd.) The purpose of this study is to develop an engineering basis for extrusion processing of low-density P foams with a large volume expansion ratio. This paper presents an effective means for the control of cell growth to achieve a desired volume expansion ratio using butane as the blowing agent. The role of branching of polypropylene materials in determining the volume expansion ration of extruded foams is investigated, and an effective processing strategy is also established to prevent the loss of gas. Since too quick crystallisation may govern the volume expansion behaviour of PP foams, a proper range of the processing temperature is required to be established. The expandability of PP materials is studied, and experimental results are presented that verify the feasibility of the proposed ideas. 46 refs.

45

References and Abstracts

CANADA; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.826078 Item 82 Polymer Testing 20, No.6, 2001, p.643-7 PREDICTION OF IMPACT PROPERTIES OF POLYOLEFIN FOAMS Iannace F; Iannace S; Caprino G; Nicolais L Napoli,Universita Federico II The mechanical response of polypropylene foam was studied over a wide range of strain rates and the linear and non-linear viscoelastic behaviour was analysed. The material was tested in creep and dynamic mechanical experiments and a correlation between strain rate effects and viscoelastic properties of the foam was obtained using viscoelasticity theory and separating strain and time effects. A scheme for the prediction of the stress-strain curve at any strain rate was developed in which a strain rate-dependent scaling factor was introduced. An energy absorption diagram was constructed. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.824983 Item 83 Antec 2001.Conference proceedings. Dallas, Texas, 6th-10th May, 2001, paper 115 EFFECT OF PROCESSING VARIABLES ON THE QUALITY OF INJECTION MOLDED FOAMED PARTS Duever T A; Tripp M T; Tzoganakis C Waterloo,University (SPE) The influence of mould temperature, curing time, extruder temperature, screw speed, compression pressure, injection pressure and cushion (the volume of molten polymer remaining in the barrel after injection) on the physical properties of injection moulded ethylene-vinyl alcohol copolymer foams was investigated using statistical design of experiments techniques. Models for the prediction of properties were compared with experimental observations. The samples were characterised by measurement of: length and weight expansion; density; hardness; split tear; compression set; and abrasion resistance. Mould temperature and curing time were the dominant factors for high-density foams, with extruder temperature having a significant influence for lower density compositions. 2 refs.

37, No.4, July 2001, p.333-52 INVESTIGATION OF THE RADIATION CROSSLINKED FOAMS PRODUCED FROM METALLOCENE POLYOLEFIN ELASTOMERS/ POLYETHYLENE BLEND Kim D W; Kim K S Chungbuk,National University; Youngbo Chemical Co.Ltd. In order to produce low-density crosslinked foam with good properties and a uniform cell structure from metallocene polyolefin elastomer(POE)/LDPE blends, the crosslinking efficiency of resin, behaviour of crosslinking sensitiser, dependence of mechanical properties on irradiation dose and compressive strength in different cell sizes were examined. When POE(ethylene-octene copolymer)/LDPE 70/30 was irradiated at 3 Mrad, the gel content was 18.5%, but the addition of 0.3 phr of triallyl-1,3,5-benzenetricarboxylate only increased gel content up to 36%. The gel fraction increase was greater with lower melt index of the resin. Although TS increased up to a certain point with increasing gel content, the decrease of TS was observed over the fixed gel content. The effect of polyfunctionality was investigated by analysing the gel fraction in accordance with the number of double bonds in molecules of crosslinking sensitisers. As a result of the measurement of changes of compressive strength according to the sizes of different foam cells, having the same degree of density, bigger cells showed stronger compressive strengths when compressed at 25%, while foams containing smaller cells showed superior compressive strengths when compressed over 50%. 19 refs. KOREA

Accession no.821775 Item 85 Plast 21 No.97, Nov.2000, p.38-9 Spanish NEW DEVELOPMENTS IN THERMOFORMING Research carried out by the Queen’s University of Belfast in the thermoforming of PP and PP foam is reviewed. Studies were made of the influence of crystallinity on thermoformability and the use of chemical blowing agents in the production of foams having lower density and optimum cell structure. Finite element modelling was used in the prediction of wall thicknesses and an optimised process control system was developed. BELFAST,QUEEN S UNIVERSITY

CANADA

EUROPEAN COMMUNITY; EUROPEAN UNION; NORTHERN IRELAND; UK; WESTERN EUROPE

Accession no.822864

Accession no.818418

Item 84 Journal of Cellular Plastics

Item 86 Patent Number: US 6187840 B1 20010213 CHEMICALLY EMBOSSED METALLOCENE

46

© Copyright 2004 Rapra Technology Limited

References and Abstracts

POLYETHYLENE FOAM Yang L-Y T; Dees M Armstrong World Industries Inc. A textured metallocene polyethylene foam sheet suitable for use in a floor covering is made using a highly coactivated azodicarbonamide package which blows the metallocene polyethylene effectively. The preferred coactivators are zinc oxide and urea. The textured surface of metallocene polyethylene foam is formed by a chemical embossing process which utilises a liquid triazole having an alkyl moiety as a foam-expansion inhibitor. The triazole is dissolved in a non-polar solvent to form the foam inhibitor. The preferred inhibitor is a hydrocarbon which may be halogenated. USA

Accession no.818219 Item 87 Advances in Polymer Technology 20, No.2, Summer 2001, p.108-15 ROTATIONAL MOULDING OF TWO-LAYERED POLYETHYLENE FOAMS Liu S-J; Yang C-H Chang Gung,University Rotational moulding of PE foams has increasingly become an important process in industry because of its resultant thicker walls, low sound transfer, high stiffness and good thermal insulation. The rotomouldability of two-layer PE foamed parts is assessed. The polymeric material used is LLDPE and the foaming material is an endothermic chemical blowing agent. Two different moulding methods, by powder and by pellet, are used to mould the multilayer foamed parts. Rotational moulding experiments are carried out in a laboratory scale uniaxial machine, capable of measuring internal mould temperature in the cycle. Characterisation of moulded part properties is performed after moulding. Optical microscopy is also employed to determine the bubble distribution in foamed parts. The final goal is to investigate how blowing agent and processing conditions can influence the process of rotational moulding and final product quality. It is found that the rotational moulding of two-layer PE foams produces parts of better impact properties, as well as fine outside surfaces. In addition, rotational moulding of foamed parts by pellets saves the cost of powder grinding, but is counteracted by uneven inner surfaces. 20 refs. TAIWAN

Accession no.818013 Item 88 Polymer Engineering and Science 41, No.5, May 2001, p.735-42 FOAMING OF LOW-DENSITY POLYETHYLENE IN A DYNAMIC DECOMPRESSION AND COOLING PROCESS Kwangjin Song; Apfel R E

© Copyright 2004 Rapra Technology Limited

Yale,University The effects of the properties of polymers and blowing agents (chloroform and methylene chloride) on the macrostructure and microstructure of foamed products in a dynamic decompression and cooling process were investigated. When the homogeneous solutions, prepared by the heating and mixing of the mixtures of LDPEs and chlorinated hydrocarbons under nitrogen, went through a rapid pressure quench above the boiling point of the liquids, bubbles nucleated out through liquid/gas phase separation and grew through diffusion and expansion of the gaseous phases. Foam cell stabilisation was improved by polymers exhibiting higher extensional hardening and blowing liquids possessing higher latent heat of evaporation. The resultant LDPE foams had mixed cell structures, more cells being closed in the skin parts but more being open in the core parts. In the polymer matrix, micromorphologies of granules, fibres and fibre networks, with oriented lamellae, were observed. The formation of these complex structures was examined in terms of phase and deformation behaviours of the solutions. 23 refs. USA

Accession no.817907 Item 89 Polymers & Polymer Composites 9, No.4, 2001, p.227-38 VISCOELASTIC PROPERTIES OF POLYETHYLENE SYNTACTIC FOAM WITH POLYMER MICROBALLOONS Lawrence E; Pyrz R Aalborg,University The use is investigated of polymeric microballoons in place of glass microballoons for the manufacture of polyethylene syntactic foams. Whilst glass microballoons have good mechanical and thermal properties, they are subject to breaking and shearing during processing. This present study deals with the viscoelastic properties of extruded PE and a foam made from PE and approximately 40 volume percent of polymer microballoons. Results are discussed of creep tests and stress relaxation tests. 6 refs. DENMARK; EUROPEAN COMMUNITY; EUROPEAN UNION; SCANDINAVIA; WESTERN EUROPE

Accession no.817541 Item 90 Cellular Polymers 20, No.2, 2001, p.79-100 MODELING THE GAS-LOSS CREEP MECHANISM IN EVA FOAM FROM RUNNING SHOES Mills N J; Rodriguez-Perez M A Edited by: Birmingham,University; Valladolid,University

47

References and Abstracts

Compressive creep experiments were performed on an EVAC foam from a running shoe. The recovery process after creep is discussed. Modelling was performed of gas diffusion perpendicular to the stress axis and along the stress axis. 16 refs.

Item 93 Patent Number: US 6174930 B1 20010116 FOAMABLE POLYPROPYLENE POLYMER Agarwal P K; Mehta A K Exxon Chemical Patents Inc.

EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; UK; WESTERN EUROPE

A foamable isotactic polypropylene homopolymer is obtained by metallocene catalysis and has a molecular weight distribution and density, which fall within broad ranges. It may be prepared in a multiple stage polymerisation process using the same metallocene component in at least two stages.

Accession no.817287 Item 91 Plastics and Rubber Weekly 8th June 2001, p.9 EPP TAKES OFF WITH RISING CAR SAFETY STANDARDS Edwards N Protection Packaging’s Newport factory has spent 10 years gradually developing a market for expanded PP automotive components that it believes has huge potential. Toolkits are its most popular in-car application, but the company also produces bumper cores, crash protection and void fillers. EPP offers the advantage that it can be recycled along with the many high-density PP parts, such as bumpers. The company also produces returnable packaging in the form of EPP component trays used in car production. Meanwhile, the Newport plant’s packaging business is shrinking as Japanese teletronics companies move mass production abroad. However, last year the company launched antistatic EPE packaging for DAT drives and is currently shipping 25,000 a month. PROTECTION PACKAGING LTD. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.816860 Item 92 Shawbury, Rapra Technology Ltd., 2001, pp.146. 30 cms., 1/6/01. Rapra Industry Analysis Series POLYMER FOAMS. TRENDS IN USE AND TECHNOLOGY Eaves D Rapra Technology Ltd. This market report on polymer foams covers foams derived from the most commonly available polymers: PU (flexible and rigid, including polyisocyanate), polyolefins (PP, PE, and ethylene copolymers), PS, phenolics, PVC and latex. The production of foams using the recently developed microcellular process is also discussed, as are physical and chemical blowing agents. Processing aids and compounding ingredients are reviewed, and for each foam type, details are given of properties, processes, markets and applications, and industry trends. Environmental considerations are also examined, with reference to the Montreal Protocol and recycling of foams. EUROPE-GENERAL

Accession no.815481

48

USA

Accession no.814133 Item 94 Polymer Testing 20, No.3, 2001, p.253-67 IMPROVEMENT OF THE MEASUREMENT PROCESS USED FOR THE DYNAMIC MECHANICAL CHARACTERISATION OF POLYOLEFIN FOAMS IN COMPRESSION Rodriguez-Perez, M A; Almanza O; del Valle JL; Gonzalez A; de Saja J A Valladolid,Universidad; Colombia,University Because there are many factors involved in the dynamic mechanical compression of polyolefin foams, the Taguchi method was employed in a Perkin Elmer DMA7 dynamic mechanical analyser to establish a method to improve the measurement process. The signal-to-noise ratio was measured to determine how the variability could be improved. Control and noise factors were evaluated and levels chosen, with details being tabulated. Appendix A describes some of the factors. Tests were conducted on two closed cell foams. NA2006 foam is 48 kg/cu m LDPE and NEE3306 foam is 32 kg/cu m EVA. Different factors were shown to influence results for E’ and tan delta but an optimum combination is proposed for the simultaneous measurement of both properties. The results were less variable as frequency was increased. Small differences in the dynamic response of different materials should be measurable because of the low variability in the experimental results. 18 refs. COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.813852 Item 95 Patent Number: US 6162380 A1 20001219 METHOD FOR PRODUCING FOAMED PLASTIC HOLLOW BODIES Kohn U; Steigerwald F Wella AG In the method of producing a hollow foamed plastic body from polyethylene or polypropylene by means of an extrusion blow-moulding process using a single-screw

© Copyright 2004 Rapra Technology Limited

References and Abstracts

extruder and a blow-moulding tool, the plastic material is foamed by means of a chemical blowing agent, and a pre-moulded tube blank formed from the foamed plastic material is blow-moulded in the blow-moulding tool. The blow-moulding tool has a tool surface temperature of at least 35 deg C over at least one portion of the surface. A blowing agent that decomposes endothermically and provides a nucleation effect is included in a blowing-agent master batch based on high density polyethylene. The master batch has an average grain size of about 1 mm and the pre-moulded tube blank is blow moulded at a pressure of from 0.5 to 2.0 bar, or the pre-moulded tube blank is blow-moulded in an interval blow-moulding process with a blow-moulding pressure of from 3 to 10 bar, preferably 8 to 10 bar, in a first time slot and a blowmoulding pressure of from 0.5 to 1.0 bar in a second time slot. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; USA; WESTERN EUROPE

Accession no.812606 Item 96 Patent Number: US 6150427 A1 20001121 2000 FOAMING PROPYLENE COPOLYMER, AND FOAMED PARTICLES AND FOAMS THEREOF Ito T; Seta Y; Tsunori R Idemitsu Petrochemical Co.Ltd. Provided are a foaming propylene-ethylene random copolymer which is characterised in that (1) its ethylene unit content (x (wt. %)) falls between 0.2 and 10% by weight, (2) its MI falls between 1 and 16 g/10 min, (3) its boiling diethyl ether extraction (E (wt. %) and x satisfy the relation of a formula (I): E larger than or equal to 0.25x+1.1 (I), (4) its melting point (Tm (degree C.)) and x satisfy the relation of a formula (II): Tm is larger than or equal to165-5x (II), (5) its isotactic triad fraction in the PPP chain moiety as measured through 13 C NMR is not smaller than 98 mol %, and preferably, (6) the relation between the time of relaxation tau (sec) of the copolymer and MI of the copolymer satisfies a formula (III): tau larger than or equal to 0.80-0.42. times log MI (III), and also its foaming beads and cellular articles. The copolymer and its foaming beads have improved primary and secondary foamability, and the cellular articles of the copolymer have excellent mechanical properties including rigidity. JAPAN; USA

Accession no.810774 Item 97 Patent Number: US 6166096 A1 20001226 PRE-EXPANDED PARTICLES OF POLYPROPYLENE RESIN, PROCESS FOR PRODUCING THE SAME AND PROCESS FOR PRODUCING IN-MOULD FOAMED ARTICLES THEREFROM

© Copyright 2004 Rapra Technology Limited

Ichimura T; Nakamura K; Senda K Kaneka Corp. A pre-expanded particle made of a blend of 10 to 90 percent by weight of a polypropylene resin having a melt index of 6 to 10 g/10 minutes and 90 to 10 percent by weight of a polypropylene resin having a melt index of 0.5 to 3 g/10 minutes. The melt index of the blend being within the range of 2 to 5 g/10 minutes. The pre-expanded particles can be moulded by an in-mould foaming method in a short time without causing sink to give polypropylene resin cellular moulded articles having good surface property and good melt adhesion of the particles. JAPAN; USA

Accession no.810209 Item 98 Plastics and Rubber Weekly 6th April 2001, p.13 PROTECTION DRIVES ON WITH EPP PARTS Edwards N Protective Packaging sees the automotive sector as positively brimming with opportunity in the coming months. The key is the growing provision of EPP components, from head restraints to side impact bars and bumper cores. The company’s Newport, South Wales, site specialises in automotive work. The Glasgow site is unusual is mixing, moulding with fabrication of EPE. The company recently opened its refurbished design office at its Blackburn headquarters. One innovative product is the supply of dissipative EPS, which removes the need for shielding bags for products like disc drives. PROTECTION PACKAGING LTD. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.810128 Item 99 Kobunshi Ronbunshu 58, No.1, 2001, p.56-8 Japanese DYNAMIC COMPRESSION MODULUS OF CLOSE-CELLED POLYETHYLENE FOAM Adachi H; Hasegawa T Nagoya,Municipal Industrial Res.Inst.Rokuban The dynamic storage modulus of closed-cell PE foams was investigated by dynamic viscoelastic measurement in the compression mode. It was found that dynamic modulus correlated with compression hardness and that the resistance against pressure inside the cells had no effect upon static modulus or dynamic storage modulus. 8 refs. JAPAN

Accession no.809551

49

References and Abstracts

Item 100 Journal of Applied Polymer Science 79, No.12, 21st March 2001, p.2146-55 STUDY ON THE FOAMING OF CROSSLINKED POLYETHYLENE Abe S; Yamaguchi M TOSOH Corp. The processing of crosslinked PE foam, with a closedcell structure, was investigated. Two types of LLDPE produced using a metallocene catalyst were crosslinked by dicumyl peroxide(DCP). The expansion ratio of the foams decreased with increasing DCP content, which was due to the enhancement of the elastic modulus. The crystallisation temp.(Tc) of the foams was also responsible for the expansion ratio. After expansion, the crosslinked foam with lower Tc shrank to a greater degree prior to the crystallisation, which was attributed to the volume reduction of the gas in the cells. As a result, the expansion ratio decreased. The degree of shrinkage decreased with increasing Tc because immediate crystallisation prevented the shrinkage. 28 refs. JAPAN

Accession no.807397 Item 101 Chimica e l Industria 82, No.3, April 2000, p.313-8 Italian COEXTRUDED POLYPROPYLENE FOAM SHEETS Delben F; Forabosco A; Casasola M Trieste,University; AMB Srl Multi-layer sheets for use in the manufacture of food packaging containers were produced by the coextrusion of PP foam in combination with PE, an EVOH barrier layer and tie layers. Results are presented of studies of the mechanical and morphological properties, density and cell structure of foam layers based on different types of PP. 8 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.807089 Item 102 Patent Number: EP 1075933 A2 20010214 MULTI-LAYER EXPANSION-MOLDED ARTICLE OF POLYPROPYLENE RESIN, PRODUCTION PROCESS THEREOF, AND CONTAINER, SHOCK-ABSORBING MATERIAL FOR AUTOMOBILE AND AUTOMOTIVE MEMBER FORMED OF THE MULTI-LAYER EXPANSION-MOLDED ARTICLE OF POLYPROPYLENE RESIN Kogure N; Gokuraku H JSP Corp. A multi-layer expansion-moulded article is obtained by moulding a multi-layer parison comprising a foamed resin

50

layer and a resin layer provided on the outer side of the foamed resin layer in a mould in such manner that at least part of the opposed inner surfaces of foamed resin layer in the parison are fusion-bonded to each other. There is a polypropylene resin layer on the surface of the foamed polypropylene resin layer. The melt tension and melt flow rate obtained by measurement of the polypropylene resin forming the layers in the expansion-moulded article satisfy given relationships. EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN; WESTERN EUROPE-GENERAL

Accession no.806641 Item 103 Patent Number: US 6130266 A1 20001010 PRE-EXPANDED PARTICLES OF PROPYLENE RESIN, PROCESS FOR PREPARING THE SAME AND FLOW-RESTRICTING DEVICE Mihayashi T; Ota N; Akamatsu N; Yanagihara Y; Satoh T Kaneka Corp. Pre-expanded particles of a propylene polymer having a high expansion ratio and excellent moulding adhesion without using a volatile blowing agent or increasing expansion pressure are disclosed. They are prepared by dispersing polymer particles comprising a propylene resin composition into an aqueous dispersion medium in a pressure vessel, heating the resulting mixture to an expansion temperature higher than the softening temperature of the particles, introducing an inorganic gas, and releasing the mixture into a lower atmosphere than the inner pressure of the pressure vessel. The mixture is expanded after the temperature of the mixture is maintained in a temperature range of not more than the expansion temperature to at least the expansion temperature -1C for at least 30 minutes. The composition contains 100 parts by weight of (A) a random copolymer of ethylene and propylene having an ethylene content of 1.5 to 4.5% by weight and 0.001 to 10 parts by weight of (B) an alkali metal salt of a copolymer of ethylene and (meth)acrylic acid. JAPAN; USA

Accession no.806328 Item 104 Patent Number: EP 1066958 A1 20010110 THERMOFORMABLE MULTI-LAYER PARTIALLY FOAMED SHEET Di Cesare G Cryovac Inc. The sheet comprises a foamed layer (a) composed of polypropylene, at least one surface of which is directly adhered to a substantially unfoamed layer (b) comprising an ethylene-based polymer. The resin employed for the foamed layer is a blend of at least about 50% by weight of polypropylene and from about 3 to less than about 50%

© Copyright 2004 Rapra Technology Limited

References and Abstracts

by weight of an ethylene/C3 to C8 alpha-olefin plastomer. The presence of the plastomer in the polypropylene foamed layer increases the bond with the directly adhering layer (b), thus preventing delamination problems upon thermoforming.

Item 107 Patent Number: US 6127441 A1 20001003 EXPANDABLE RESIN COMPOSITION Sakamoto T; Ishihara K; Furukawa T Nippon Unicar Co.Ltd.

EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN EUROPE-GENERAL

This comprises (A) 100 pbw of HDPE having a DSC melting point of about 127 to 136C, a density of 0.945 to 0.967 g/cu.cm. and a melt flow rate of about 0.1 to 10 g/ 10 min. and, for each 100 pbw of A, (B) about 2 to 50 pbw of PP having a DSC melting point of at least about 130C, (C) about 50 to 200 pbw of an ethylene/alpha-olefin copolymer obtained using a metallocene catalyst and having a DSC melting point of about 98 to 121C, a density of 0.900 to 0.935 g/cu.cm. and a melt flow rate of about 0.5 to 3 g/10 min., (D) about 0.1 to 5 pbw of a polysiloxane-polyether block copolymer of given formula and (E) about 0.02 to 5 pbw of a nucleating agent, such as azodicarbonamide, talc or mixtures thereof.

Accession no.805974 Item 105 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 703 EFFECT OF CHEMICAL BLOWING AGENT DOSAGE ON THE PROPERTIES OF EXTRUDED EXPANDED POLYPROPYLENE Dixon D; Martin P J; Harkin-Jones E Belfast,Queen’s University (SPE) The influence of chemical blowing agent concentration on die temperature and premature foaming, and on the cell density, density, tensile strength and shrinkage of extruded polypropylene foam was investigated. The blowing agent, a bicarbonate/citric acid based material, was used in concentrations in the range 0.1-1.0%. The optimum dosage, which gave the highest cell density in conjunction with a low density, was 0.5%. The tensile strength decreased with increasing blowing agent concentration. 6 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.805711 Item 106 Polyolefins 2000. Conference proceedings. Houston, Tx., 27th Feb.-1st March 2000, p.449-56 THIN GAUGE POLYETHYLENE FOAM EXTRUSION Sreenath G K Battenfeld Gloucester Engineering Co.Inc. (SPE,South Texas Section; SPE,Thermoplastic Materials & Foams Div.; SPE,Polymer Modifiers & Additives Div.) Thin gauge PE foams have been increasingly used for protective packaging over the past few years. However, very little processing data has been available. Process conditions for a continuous extrusion process to manufacture thin gauge PE foam are outlined. A specification defining the range of thickness and density is proposed and extrusion conditions documented. Typical process issues are discussed. A high-speed winding technology to wind thin gauge PE foam sheet is summarised. 3 refs. USA

Accession no.803470

© Copyright 2004 Rapra Technology Limited

JAPAN; USA

Accession no.802931 Item 108 Patent Number: US 6129798 A1 20001010 PROCESS FOR MANUFACTURING AN ETHYLENE VINYL ACETATE INSOLE Yang Y-C; Lu S-F This involves weighing moulding compounds for manufacturing the insole. The moulding compounds are mixed and rolled by means of a roller to form a sheet material, which is then cut into elongated strips. A predetermined amount of the strips are placed into a first mould unit, which is heated and pressurised to form a partially foamed insole. The partially foamed insole is placed into a second mould unit, which is heated, pressurised and cooled to form a completely foamed insole, which is then trimmed. USA

Accession no.802882 Item 109 Patent Number: US 6114025 A1 20000905 FOAM AND FILM/FOAM LAMINATES USING LINEAR LOW DENSITY POLYETHYLENE DeVaudreuil M D; Crowell J M; Smith A R; Wilkes G R Tenneco Protective Packaging Inc. A polymeric composition for use in foam manufacture comprises a linear low density polyethylene and a resiliency modifier resin. The linear low density polyethylene is present in an amount of from about 1 to 90 weight percent of the polymeric composition and has a z-average molecular weight greater than about 700,000. The resiliency modifier resin is present in an amount of from 10 to about 99 weight percent of the polymeric composition and may be a low density polyethylene.

51

References and Abstracts

Reclaimed material may comprise a portion of the linear low density polyethylene. USA

Accession no.801269 Item 110 Patent Number: US 6124025 A1 20000926 POLYPROPYLENE-BASED FOAMED SHEET Kitayama T; Tsubouchi K; Matsubara S Sumitomo Chemical Co.Ltd.

moulding and extrusion moulding. Rheological properties of the polypropylene resin, processing conditions and choice of composition of the chemical blowing agent were found to play important roles in obtaining high quality polypropylene foam structures. High strength fine-cell polypropylene foams could in particular be formed by first melt compounding a suitable chemical blowing agent with the resin under conditions which allow for homogeneous mixing without appreciable decomposition of the blowing agent. USA

The present invention provides a polypropylene-based foamed sheet whose expansion ratio is 4 or more times characterised by expansion ratio A of the part (skin layer) up to 20% in each of the seat thickness from both surface of said polypropylene-based foamed sheet and expansion ratio B of part other than said skin layer (core layer) satisfying the following formula (1): 1.3 less than or equal to B/A. The polypropylene-based foamed sheet of the present invention is excellent in the balance of lightweight properties and rigidity.

Accession no.800405

JAPAN; USA

Disclosed are ethylene-vinyl acetate/ethylene-styrene interpolymer blends, which are useful in preparing foams exhibiting improved compression set resistance, dimensional stability and rebound resilience at similar foam densities than known foam systems, e.g. EVA. The crosslinked foams are particularly useful in fabricating footwear and gaskets.

Accession no.801013 Item 111 Plastiques & Elastomeres Magazine 52, No.4, May 2000, p.27 French POLYURETHANES GO INTO HOSPITAL Topuz B A hospital trolley developed by Bayer and GMP is described. The trolley is equipped with a portable computer for the collection and management of patient information with the aim of reducing medical errors. The main component is a sandwich structure reaction injection moulded in Bayer’s Baydur 60 PU and consisting of a cellular core and a smooth skin. Other components are made of PP, PMMA or polycarbonate. Developments by GMP in the use of PU foams in refrigerator manufacture are also reviewed, and turnover figures are presented for the Company. BAYER AG; GMP; SMEG; CANNON GROUP; ELECTROLUX AB EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; ITALY; SCANDINAVIA; SWEDEN; WESTERN EUROPE

Accession no.800834 Item 112 Patent Number: US 6103153 A1 20000815 PRODUCTION OF FOAMED LOW-DENSITY POLYPROPYLENE BY ROTATIONAL MOLDING Park C B; Liu G; Liu F; Pop-Iliev R; D’Uva S; Zhang B Compositions and processing conditions are disclosed for the production by rotomoulding of polypropylene foams, hitherto satisfactorily produced only by injection

52

Item 113 Patent Number: US 6111020 A1 20000829 CROSSLINKED FOAMS FROM BLENDS OF ETHYLENE VINYL ACETATE AND ETHYLENESTYRENE INTERPOLYMERS Oriani S R; Karande S V Dow Chemical Co.

USA

Accession no.800259 Item 114 Patent Number: US 6110986 A1 20000829 PROPYLENE-BASED POLYMER COMPOSITION AND FOAMED ARTICLE THEREOF Nozawa H; Wakamatsu K; Nagamatsu T Sumitomo Chemical Co.Ltd. A propylene-based polymer composition is obtained by polymerising a propylene monomer in the presence of a stereoregular olefin polymerisation catalyst system in the first stage to produce a crystalline propylene-based polymer (A) having an intrinsic viscosity of 5 dl/g or more, and successively polymerising a propylene monomer in the second stage to produce a crystalline propylene-based polymer (B) having an intrinsic viscosity of less than 3 dl/g. The content of (A) is in the range of 0.05% by weight or more and less than 35% by weight of the total of the polymers (A) and (B) and the total of the polymers (A) and (B) has an intrinsic viscosity of less than 3 dl/g and a Mw/Mn of less than 10. JAPAN; USA

Accession no.800226 Item 115 International Journal of Polymeric Materials

© Copyright 2004 Rapra Technology Limited

References and Abstracts

47, No.1, 2000, p.7-17 POLYETHYLENE FOAM WASTE UTILISATION FOR LIGHTWEIGHT CONCRETE PRODUCTION Perevozchikov A; Yakovlev G; Kodolov V Udmurt,Scientific Centre; Russian Academy of Sciences An investigation was carried out on concrete containing up to 30% of PE foam waste in order to optimise the thermal conductivity of the concrete. An amorphous aggregate of ash-slag waste was utilised to decrease the thermal conductivity of the concrete. 5 refs. RUSSIA

Accession no.800201 Item 116 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 404 DEVELOPMENT OF POLYPROPYLENE PLANK FOAM PRODUCTS Park C P; Garcia G A Dow Chemical Co. (SPE) The foamability of a number of polypropylenes, including polymers branched using an azidofunctional silane, was investigated, using mixtures of chlorofluorocarbons and hydrochlorofluorocarbons as foaming agents. The polymers were characterised by determination of their viscoelastic properties at 190 C. The foamability was studied using a range of foaming agent concentrations and cell sizes, with a 25 mm foam extruder. A slit die was used to make regular planks, and a multi-hole die to make strand planks. The multi-hole die was designed to force the foam strands together into a coalesced structure. The successful production of the plank was attributed to the achievement of bubble stability by the use of low foam densities and small cell sizes. 11 refs. USA

Accession no.799919 Item 117 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 402 LOW DENSITY FOAMING OF POLY(ETHYLENE-CO-OCTENE) BY INJECTION MOLDING Moulinie M; Daigneault L E; Woelfle C; Gendron R Canada,National Research Council (SPE) Low density poly(ethylene-co-octene) foams were prepared by injection moulding compositions consisting of copolymer, azodicarbonamide foaming agent, zinc oxide and zinc stearate activators, dicumyl peroxide crosslinking agent and talc nucleating agent. The influence of composition on the foam density and morphology was

© Copyright 2004 Rapra Technology Limited

investigated using one set of processing conditions. Proper bubble growth required the matching of the crosslinking agent concentration to the initial polymer viscosity. Optimisation of the formulation resulted in densities as low as 72 kg/cu m, and average cell sizes as small as 28 micrometre. 3 refs. CANADA

Accession no.799917 Item 118 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 269 PROCESSING OF POLYPROPYLENE FOAMS IN MELT COMPOUNDING BASED ROTATIONAL FOAM MOLDING Pop-Iliev R; Park C B Toronto,University (SPE) A process for the production of polypropylene foams by rotational moulding is proposed. The polymer, in powder form, is first mixed with azodicarbonamide blowing agent and zinc oxide activator by melt compounding, using a twin-screw compounder. The prepared material is then converted into pellets which are used in the rotational moulding process. The process was investigated experimentally using a variety of polypropylenes with melt flow rates in the range 5.5-35 dg/min, 3-fold and 6fold foamable compositions being prepared. The best cell morphologies were obtained using high melt strength grades. The cell morphologies were not as good as those of the corresponding polyethylene foams, but were significantly better than those processed using a dry blending approach. 19 refs. CANADA

Accession no.798551 Item 119 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 268 ROTATIONAL MOLDING OF POLYETHYLENE FOAM BY PELLETS Shih-Jung Liu; Ching-Hsiung Yang Chang Gung,University (SPE) The rotational moulding of linear low density polyethylene foam using powder or pellets and an endothermic chemical blowing agent was investigated using a laboratory uniaxial machine with oven temperatures in the range 250-400 C, the internal mould temperatures being measured during heating and cooling. Two-layer samples were produced consisting of a nonfoamed outer layer and a foamed inner layer. The samples were evaluated by tensile and impact testing, and determination of thickness uniformity and warpage. Density decreased with increasing oven temperature. The presence of the blowing agent gave an improvement in

53

References and Abstracts

impact properties, but adversely affected the tensile strength. The use of pellets gave severe non-uniform thicknesses. Two-layer parts with a non-foamed outer layer had high impact properties and good outer surfaces. 6 refs. TAIWAN

Accession no.798550 Item 120 Patent Number: US 6103775 A1 20000815 SILANE-GRAFTED MATERIALS FOR SOLID AND FOAM APPLICATIONS Bambara J D; Kozma M L; Hurley R F Sentinel Products Corp.

undergoes a combination of compression and high shear and extensional conditions, resulting in fragmentation/ fracture into a fine powder without melting. Depending on conditions, the polymer may undergo chain scission, resulting in highly reactive free radicals at chain ends. Radical combination reactions at interfaces and in regions of efficient mixing may result in block copolymer formation similar to that achieved with reactive compatibilisation during melt processing of functionalised polymers. A PP/PS blend processed via S3P is compared with an identical blend processed solely via melt mixing methods. The pulverised blend is compatibilised while the properties of the melt mixed blend evolve with annealing. 14 refs. USA

New crosslinked polymeric foam compositions, and methods for making the same, are provided. The new compositions utilise novel crosslinked polyolefin copolymers and show improvements in strength, toughness, flexibility, heat resistance and heat-sealing temperature ranges as compared to conventional low density polyethylene compositions. The new compositions also show processing improvements over linear low density polyethylene. The novel polyolefins, which are essentially linear, comprise ethylene polymerised with at least one alpha-unsaturated C3 to C20 olefinic comonomer, and optionally at least one C3 to C20 polyene, and exhibit, in an uncrosslinked sense, a resin density in the range of about 0.86 g/cm3 to about 0.96 g/cm3, a melt index in the range of about 0.5 dg/min to about 100 dg/min, a molecular weight distribution in the range of from about 1.5 to about 3.5, and a composition distribution breadth index greater than about 45 percent. The polyolefins are silane-grafted to enhance the physical properties and processability of the resins. Slow silanegrafted materials exhibit enhanced physical and processing properties. USA

Accession no.797897 Item 121 Polymer Preprints. Volume 40. Number 2. August 1999. Conference proceedings. New Orleans, La., August 1999, p.752-3 POLYSTYRENE/POLYPROPYLENE POLYMER BLEND COMPATIBILISATION WITHOUT ADDITION OF PREMADE BLOCK OR GRAFT COPOLYMERS OR FUNCTIONALISATION Furgiuele N; Khait K; Torkelson J M (ACS,Div.of Polymer Chemistry) A novel approach is used to compatibilise a blend without addition of premade copolymers or functionalisation of polymers lacking functional groups. Solid-state shear pulverisation (S3P) processes polymers at temperatures below the melt transition (for semicrystalline polymers) or the glass transition (for amorphous polymers). The polymer, introduced as pellets or flakes into the pulveriser,

54

Accession no.797243 Item 122 Patent Number: US 6096793 A1 20000801 FOAM COMPRISING POLYOLEFIN BLEND AND METHOD FOR PRODUCING SAME Lee S-T; Baker J J Sealed Air Corp. A foam comprising a blend of a low density polyethylene and an ethylene/alpha-olefin copolymer is disclosed. The ethylene/alpha-olefin copolymer is preferably LLDPE and has a density ranging from about 0.86 to 0.94 grams/cubic centimeter and a melt flow index of greater than 10 g/10 minutes. USA

Accession no.796855 Item 123 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 70 NUCLEATION IN FOAM EXTRUSION Lee S T Sealed Air Corp. (SPE) An intermeshing counter-rotating twin screw extruder was used to produce polyethylene foam, using carbon dioxide with no nucleating agent as the blowing agent. The extruded sheet was characterised by counting cells across the sheet thickness and converting to nucleation cell density. Experiments were conducted using a constant carbon dioxide ratio with various die openings, and a constant die opening with various carbon dioxide ratios. Conventional nucleation theories did not adequately describe the nucleation in the absence of a nucleating agent, and it is proposed that chemical superheat rather than mechanical superheat was a critical factor in the nucleation rate. There was also a dependence upon shear energy. 8 refs. USA

Accession no.793801

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 124 Patent Number: US 6077878 A1 20000620 FOAM MADE FROM MODIFIED POLYPROPYLENE RESIN AND PROCESS FOR THE PRODUCTION THEREOF Okura T; Kourogi M; Fukui Y; Kim H; Tomita H; Miyama O; Aoyama T Kanegafuchi Kagaku Kogyo KK The modified polypropylene resin is a graft copolymer of polypropylene and an aromatic vinyl monomer and has an average number of grafted aromatic vinyl chains of not less than 1 in one molecule of the graft copolymer and a weight-average molecular weight of the grafted aromatic vinyl chains of not less than 200. The foamed article has a high closed cell content, a high expansion ratio and good external appearance. JAPAN; USA

Accession no.793452 Item 125 Patent Number: US 6077875 A1 20000620 FOAMED AND EXPANDED BEADS OF POLYPROPYLENE RESIN FOR MOLDING Sasaki H; Sakaguchi M; Akiyama M; Tokoro H JSP Corp.

Item 127 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 49 EXTRUSION OF CLOSED CELL VERY LOW DENSITY FLEXIBLE SYNTACTIC FOAMS USING METALLOCENE CATALYZED POLYOLEFINS AND THERMOPLASTIC MICROBALLOONS Trainer L J; Beauregard D; Orroth S; Schott N Massachusetts,University (SPE) The work to develop a foam jacketing material for underwater communication cable applications, with a maximum density of 550 kg/cu m, is reported. The base material was a poly(ethylene-co-octene) thermoplastic elastomer, which was used with a syntactic foaming agent consisting of microballoons with a thermoplastic acrylic shell encapsulating isopentane. During extrusion the microballoons softened, and on exiting the die they expanded under the pressure exerted by the isopentane. Analysis of variance was used to determine the influence of screw speed, processing temperatures, and microballoon concentration on the foam density. The density was largely determined by the microballoon concentration and the screw speed, but both barrel temperature and die temperature also had significant effects. USA

The beads comprise an uncrosslinked propylene random copolymer having a melting point of at least 140C, as a base resin. The time required to attenuate an air pressure within the foamed beads applied by a pressurising treatment with air from 1.2 to 0.8 kgf/sq.cm.(G) under atmospheric pressure at 23C is at least 80 minutes and the CNI value of the foamed beads, which is defined by a given equation, is smaller than 3.80. JAPAN; USA

Accession no.793449 Item 126 Kobunshi Ronbunshu 57, No.9, 2000, p.561-8 Japanese RECYCLING TECHNOLOGY FOR LAMINATES COMPOSED OF THERMOPLASTIC POLYOLEFIN ELASTOMER AND CROSSLINKED POLYPROPYLENE FOAM Tarsuda N; Sato N; Fukumori K; Kako C; Nishimura H Toyota Motor Corp. Details are given of the development of new technology for the recycling of composites of thermoplastic elastomer skinlayers and PP foam layers without deterioration in mechanical properties. The technology is based on resolving the crosslink structure of PP foam by a reactive agent injected into an extruder and finely dispersing decrosslinked PP foam into the thermoplastic elastomer matrix by high shear force. 11 refs.

Accession no.791361 Item 128 Cellular Polymers 19, No.4, 2000, p.271-85 MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED-CELL MICROCELLULAR ETHYLENE-OCTENE COPOLYMER: EFFECT OF PRECIPITATED CACO3 FILLER AND BLOWING AGENT Nayak N C; Tripathy D K Indian Institute of Technology The morphology of the microcellular ethylene-octene copolymer (Engage from DuPont Elastomers), both unfilled and filled with precipitated calcium carbonate, was studied by SEM, the concentrations of blowing gent and precipitated calcium carbonate filler being varied. The average cell size, maximum cell size and cell density varied with variation of blowing agent and filler loading. Physical properties such as relative density, hardness, TS, EB, modulus and tear strength decreased with blowing agent concentration. The elastic nature of closed cells reduced the hysteresis loss compared with solid compounds. Stress relaxation behaviour was independent of blowing agent loading, i.e. density of closed cell microcellular vulcanisates. Theoretically, flaw sizes were found to be about 2.4 times larger than maximum cell sizes observed from SEM photomicrographs. 27 refs. DUPONT ELASTOMERS

JAPAN

INDIA

Accession no.792500

Accession no.791246

© Copyright 2004 Rapra Technology Limited

55

References and Abstracts

Item 129 Patent Number: US 6066393 A1 20000523 POLYOLEFIN/IONOMER BLEND FOR IMPROVED PROPERTIES IN EXTRUDED FOAM PRODUCTS Lee S-T Sealed Air Corp. Ionomer present in a polyethylene resin from about 1 to 40% by weight of the resin produces superior extruded foam sheet products which approach the pore size and resiliency of foams prepared from chemical blowing agents. The results can be achieved at normal extrusion rates and on standard extrusion foaming equipment.

essentially amorphous and range from those that have low modulus and high elongation to those that have higher modulus with unique stress relaxation and deadfold properties. Interpolymers have both aromatic and aliphatic functionality. Hence, they are compatible with a variety of other thermoplastics. Interpolymers have been commercially launched under the trademark Index Interpolymers and are classified as E-Series (up to about 45 wt.% styrene) or S-series (greater than about 45 wt.% styrene). The properties of blends of interpolymers with LDPE, HDPE, PP and PS are described, together with the novel and unique foams made by expanding some of these blends with physical blowing agents. 9 refs.

USA

EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; USA; WESTERN EUROPE

Accession no.790627

Accession no.789417

Item 130 Patent Number: US 6083434 A1 20000704 ROTATIONAL MOLDING PROCESS FOR PRODUCING FOAMED ARTICLES Strebel J J Equistar Chemicals LP

Item 132 Polymer Testing 19, No.7, Oct.2000, p.831-48 DYNAMIC MECHANICAL ANALYSIS APPLIED TO THE CHARACTERISATION OF CLOSED CELL POLYOLEFIN FOAMS Rodriguez-Perez M A; de Saja J A Valladolid,Universidad

Improved compositions useful for the production of rotomoulded articles having a foamed interior and nonfoamed exterior skin are provided. The compositions of the invention are comprised of a first thermoplastic resin component which is an ethylene polymer in pellet form containing a chemical foaming agent, an organic peroxide and, optionally, a metal-containing activator compound and a second resin component which is a powder and can be a thermoplastic ethylene polymer or ethylene copolymer having less than 30% crystallinity. An improved one-step process for producing foamed rotomoulded articles having foamed interiors and nonfoamed exterior skins is also provided. USA

Accession no.790443 Item 131 Journal of Cellular Plastics 36, No.5, Sept./Oct.2000, p.397-421 FOAMS MADE FROM BLENDS OF ETHYLENE STYRENE INTERPOLYMERS WITH POLYETHYLENE, POLYPROPYLENE AND POLYSTYRENE Chaudhary B I; Barry R P; Tusim M H Dow Chemical Co.; Dow Deutschland Inc. Insite technology from Dow Chemical has enabled the production of ethyl ethylene-styrene interpolymers (ESI) by copolymerisation of ethylene and styrene monomers. The properties of interpolymers vary significantly with copolymer styrene content. Interpolymers with up to about 45 wt.% copolymer styrene are semi-crystalline and exhibit good low temperature toughness. Interpolymers with greater than about 45 wt.% copolymer styrene are

56

A collection of polyolefin foams with closed cell structure and different chemical compositions and densities was studied by using SEM, DSC and dynamic mechanical analysis. Deformation mechanisms were also studied. 26 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.786639 Item 133 Patent Number: US 6069183 A1 20000530 FOAMABLE COMPOSITION USING HIGH DENSITY POLYETHYLENE Wilkes G R; Kisner R D; Stimler J J Tenneco Packaging Inc. A polymeric composition for producing foam in which the polymeric composition comprises high density polyethylene, alkenyl aromatic polymer and, optionally, a resiliency modifier resin. The high density polyethylene is in an amount of from about 45 to about 90 weight percent of the polymeric composition. The high density polyethylene has a z- average molecular weight, M.sub.z, greater than about 1,000,000. The alkenyl aromatic polymer is in the amount of from about 3 to about 45 weight percent of the polymeric composition. The resiliency modifier resin is in the amount of from 0 to about 40 weight percent of the polymeric composition. The foam is produced in the absence of a significant amount of a stability control agent. USA

Accession no.786161

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 134 Journal of Applied Polymer Science 77, No.7, 15th Aug.2000, p. 1478-87 MORPHOLOGIES OF BLENDS OF ISOTACTIC POLYPROPYLENE AND ETHYLENE COPOLYMER BY RAPID EXPANSION OF SUPERCRITICAL SOLUTION AND ISOBARIC CRYSTALLIZATION FROM SUPERCRITICAL SOLUTION Han S J; Lohse D J; Radosz M; Sperling L H Exxon Research & Engineering Co.; Lehigh,University; Louisiana,State University By rapid expansion of supercritical propane solution (RESS), and isobaric crystallisation (ICSS), isotactic polypropylene and ethylene-butylene copolymers were precipitated from the supercritical solution. The RESS process produced microfibres with a trace of microparticles, while the ICSS process produced microcellular products. Improvement in thermal stability was achieved by first synthesising a thermoplastic vulcanisate from polypropylene and ethylene-propylenediene terpolymer from a supercritical propane solution, followed by RESS. 28 refs. USA

Accession no.786053 Item 135 Journal of Cellular Plastics 36, No.4, July/Aug.2000, p.310-26 PREDICTING THE PERFORMANCE OF CHEMICAL BLOWING AGENTS USING THERMAL ANALYSIS TECHNIQUES Dixon D; Martin P J; Harkin-Jones E Belfast,Queen’s University The relationship between the cell morphology of extruded expanded PP and the thermal decomposition behaviour of chemical blowing agents used in their production was studied. The thermal analysis techniques used were DSC and TGA. Tests were completed on six of the chemical blowing agents currently available for use with PP. It was found that agents with a higher decomposition temp. and rate of gas evolution generally produced foam samples with a smaller cell size and higher cell density. The smallest, densest and most uniform cell structure was produced using Boehringer HP20P, an endothermic bicarbonate/citric acid-based blowing agent. The older and lower cost azodicarbonamide-based agent performed well and was shown to be better than most of the bicarbonate/citric acid-based agents. 5 refs. BOEHRINGER EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.785739 Item 136 Patent Number: US 6040351 A1 20000321

© Copyright 2004 Rapra Technology Limited

FOAM RUBBER COMPOSITION AND A MOLDED PRODUCT OF FOAM RUBBER Okita T; Nakashima K; Mizushima T; Wadaki T Toyoda Gosei Co.Ltd. The composition contains (A) a low-molecular ethylenepropylene-5-ethylidene-2-norbornene terpolymer having a Mooney viscosity (ML 1+4 at 100C) of 20 to 40, an ethylene/propylene weight ratio of 65/35 to 50/50, an iodine value of 20 to 30 and a Q value (Mw/Mn) not exceeding 3, as determined by gel permeation chromatography, (B) a high-molecular ethylenepropylene-5-ethylidene-2-norbornene terpolymer having a Mooney viscosity of 100 to 300, an ethylene/propylene weight ratio of 65/35 to 50/50, an iodine value of 20 to 30 and a Q value (Mw/Mn) of 6 to 10, (C) a vulcanising agent containing sulphur and zinc carbamate and sulphenamide as accelerators and (D) a foaming agent containing N,N’-dinitrosopentamethylenetetramine and urea. JAPAN; USA

Accession no.784773 Item 137 Patent Number: US 6040348 A1 20000321 COMPOSITION BASED ON PROPYLENE POLYMERS FOR EXPANDED GRANULES, PROCESS FOR OBTAINING IT AND ITS USE Delaite E; Charlier J; Bertozzi G Solvay Polyolefins Europe-Belgium SA The composition comprises, per 100 pbw, from 60 to 90 pbw of a propylene homopolymer (A) having a melt flow index from 0.1 to 20 g/10 min and from 40 to 10 pbw of a propylene random copolymer (B) containing from 3 to 20 mol % of ethylene and/or an alpha-olefin having from 4 to 6 carbon atoms, the melt flow index of which ranges from 25 to 3000 g/10 min. It is used in the manufacture of expanded granules and moulded cellular articles. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; USA; WESTERN EUROPE

Accession no.784770 Item 138 Polymer Engineering and Science 40, No.8, Aug.2000, p.1843-9 ON-LINE NIR SENSING OF CO2 CONCENTRATION FOR POLYMER EXTRUSION FOAMING PROCESSES Nagata T; Tanigaki M; Ohshima M Kyoto,University Details are given of the development of an on-line sensor using near IR spectroscoy for monitoring carbon dioxide concentration in polymeric extrusion foaming processes. The calibration curve relating the absorbance spectrum at 2019 nm to the dissolved gas concentration was derived so as to infer dissolved carbon dioxide gas concentration

57

References and Abstracts

on-line from measured NIR spectra. Data are presented for carbon dioxide in PP. 9 refs. JAPAN

Accession no.782987 Item 139 Patent Number: EP 1016690 A2 20000705 WATER-CONTAINING POLYPROPYLENE RESIN COMPOSITION AND PRE-EXPANDED PARTICLES MADE THEREOF Mogami K; Munakata Y; Senda K Kaneka Corp. Disclosed is a pre-expanded particle having a high expansion ratio and excellent flexibility and cushioning property. In-moulded articles made thereof do not lose their mechanical strength, heat resistance and water resistance without conventional volatile organic foaming agents or carbon dioxide gas. The PP particle is prepared by pre-expanding a water-containing propylene composition comprising (A) 100 pbw of a PP having a melt flow rate (230C, 2.16kg load) of 10 to 70 g/10 min and a tensile elongation at break of at least 300%; (B) 0.05 to 10 pbw of a hydrophilic polymer; and (C) 0 to 3 pbw of a filler and having a water content of 1 to 20% by weight under a water vapour pressure at the melting point of the PP. The particle has an apparent expansion ratio of 25 to 70 times, a closed cell content of at least 85% and an average cell diameter of 50 to 500 micrometers. EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN; WESTERN EUROPE-GENERAL

Accession no.778602 Item 140 New Materials/Japan Feb.2000, p.2 HIGH EXPANSION POLYPROPYLENE REPLACES POLYSTYRENE Grand Polymer has developed a PP that can replace PS in extrusion moulding applications. The PP has high foaming properties and can be used for expanded sheet applications, unlike conventional PP. The company is planning to replace PS in such application areas as products used with microwave ovens, expanded deep draws for processed food, large vacuum/pressure forming products and large blow moulding products as well as finding new application areas. The PP is an ultra-high crystallisation grade with a precisely controlled molecular structure, that can be processed into good-quality expanded sheets even at a high expansion rate because its melt tension strength is more than double that of conventional PP. This abstract includes all the information contained in the original article. GRAND POLYMER CO.LTD. JAPAN

Accession no.777982

58

Item 141 Patent Number: US 5900195 A 19990504 PROTECTION OF PIPELINE JOINT CONNECTIONS Pool P L; Gowan W H Urethane Products International A method and apparatus for protecting exposed pipeline joints on weight coated pipelines used in offshore applications. The method allows quick installation on a lay barge where pipeline sections are being welded together for offshore installation. The method does not require a long cure time before handling. The method protects the corrosion coating on pipeline joint sections not covered with weight coat by forming a pliable sheet of polyethylene into a cylindrical cover material sleeve over the exposed pipeline joint connection. Polyurethane chemicals are reacted to form a high density foam which fills an annular space between the pipe and the cover material sleeve. The cover material sleeve and the foam form a composite system to protect the joint connection whereby the foam provides continuous compressive reinforcements and impact resistance and the sleeve provides puncture resistance and protection from water jetting/post trenching operations plus abrasion resistance. USA

Accession no.774425 Item 142 Advances in Polymer Technology 19, No.2, Summer 2000, p.87-96 SURROUNDING TEMPERATURE EFFECTS ON EXTRUDED POLYETHYLENE FOAM STRUCTURE Lee S-T; Lee K Sealed Air Corp. The effects of variations in the surrounding temperature on the cell structure and density of extruded PE foams were investigated. Tests were carried out on cellular LLDPE and LDPE dry blended with Hydrocerol CF-20, a masterbatch consisting of citric acid and sodium bicarbonate in a LDPE carrier. Foam rod samples were extruded into air, water and water/ice from a single-screw extruder and analysed using polarised light microscopy. Graphs of foam density versus melt temperature, cell density versus surrounding temperature and screw speed and foam density and cell density versus surrounding temperature are presented and discussed. 11 refs. USA

Accession no.774107 Item 143 Journal of Polymer Science: Polymer Physics Edition 38, No.7, 1st April 2000, p.993-1004 PREDICTION OF THE RADIATION TERM IN THE THERMAL CONDUCTIVITY OF CROSSLINKED CLOSED CELL POLYOLEFIN

© Copyright 2004 Rapra Technology Limited

References and Abstracts

FOAMS Almanza O A; Rodriguez-Perez M A; Saja J A Colombia,University A series of low density polyolefin foams were manufactured and studied in terms of their thermal conductivity, cellular structure and polymer matrix morphology. In order to predict the thermal conductivity of a specified material a mathematical equation is presented. 26 refs. COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.773154 Item 144 Italian Technology No.1, May 2000, p.69-70 EPP FOR THERMOFORMING Foamed PP is a new alternative material for processors of PP or PS thermoformed items for packaging applications. The joint R&D programme of Italproducts, Reedy International and PP resin suppliers has made it possible for everybody involved in the packaging industry to install and run an extrusion and thermoforming line capable of producing medium density EPP items. The features of the equipment required are described. ITALPRODUCTS SRL; REEDY INTERNATIONAL CORP. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.772655 Item 145 Journal of Cellular Plastics 36, No.1, Jan./Feb.2000, p.29-44 NONISOTHERMAL MELTING AND CRYSTALLISATION OF FOAMED CROSSLINKED POLYETHYLENE Kotzev G; Touleshkov N; Christova D; Nedkov E Bulgarian Academy of Sciences Foamed crosslinked specimens of LDPE are produced by hot mould injection moulding. Dicumyl peroxide as crosslinking agent and azodicarbonamide as blowing agent, are used. The three components are blended and granulated in advance in an extruder-granulator at temperatures of 100-125 deg.C. The contents of blowing and crosslinking agents in the composites studied are 515 and 0.08-0.6, respectively, in percents by weight. The ability for maximum foaming is studied by determining the overall density of the specimens. Degree of crosslinking is calculated from the equilibrium strain value defined at temperature 140 deg.C and pressure stress 0.045 MPa. The same parameter is estimated also by the melt flow index. The LDPE morphological parameters are determined on the basis of DSC graphics obtained by a Perkin-Elmer DSC-7 differential scanning calorimeter at heating and cooling rates of 10 deg.C/min. The

© Copyright 2004 Rapra Technology Limited

activation energy for transport through phase boundary crystal melt, the surface energy of the crystal, the long period and the degree of the crystallinity are calculated by computer programs using formulae of non-isothermal melting and crystallisation kinetics theory. 19 refs. BULGARIA; EASTERN EUROPE

Accession no.769807 Item 146 Journal of Vinyl and Additive Technology 6, No.1, March 2000, p.49-52 MOISTURE CROSSLINKING PROCESS FOR FOAMED POLYMERS Pape P G Dow Corning Corp. The benefits of the Sioplas moisture crosslinking process for the manufacture of crosslinked PE foam and the enduses of such foams are discussed. The process involves grafting of alkoxysilanes onto ethylene homo- or copolymers to provide moisture crosslinkable polymers suitable for the manufacture of flexible, rigid, open-celled, closed-cell or very low density foams. 11 refs. USA

Accession no.769390 Item 147 Journal of Vinyl and Additive Technology 6, No.1, March 2000, p.34-8 AGEING MODIFIERS FOR EXTRUDED LDPE FOAM Dieckmann D; Holtz B American Ingredients Co. The results are reported of a study of the effect of several glycerol ester ageing modifiers used to regulate the isobutane/air interchange on the properties of extruded LDPE foams. Properties investigated included dimensional stability, electrostatic decay and rub-off of excess wax at the surface of the foam. Comparisons are made with the non-glyceride modifier, stearamide. 4 refs. USA

Accession no.769388 Item 148 Patent Number: EP 997493 A1 20000503 CROSSLINKED OLEFIN ELASTOMER FOAM AND ELASTOMER COMPOSITION THEREFOR Sueda T; Yasaka N; Yoo C; Yoon J; Choi K; Lee K Mitsui Chemicals Inc. The foam has a specific gravity of 0.05 to 0.2, an expansion ratio of 8 to 15, a compression set of 30 to 60% and a tear strength of 1.5 to 2.5 kg/cm. It is obtained by heating an elastomer composition comprising a specific ethylene/alpha-olefin copolymer, an organic peroxide, a crosslinking auxiliary and a foaming agent. The crosslinked foam has a high expansion ratio, is free from

59

References and Abstracts

surface roughening attributed to defoaming, exhibits a soft touch and low compression set and has excellent mechanical strength (particularly tear strength) and heat resistance. EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN; WESTERN EUROPE-GENERAL

Accession no.769126 Item 149 Macromolecular Symposia Vol 147, Dec.1999, p.127-37 TENSILE DEFORMATION BEHAVIOUR OF THE POLYMER PHASE OF FLEXIBLE POLYURETHANE FOAMS AND POLYURETHANE ELASTOMERS van der Heide E; van Asselen O L J; Ingenbleek G W H; Putman C A J Shell Research & Technology Centre Atomic force microscopy and attenuated total reflection infrared spectroscopy were used to study the changes occurring in the micromorphology of a single strut of flexible polyurethane foam. A mathematical model of the deformation and orientation in the rubbery phase, but which takes account of the harder domains, is presented which may be successfully used to predict the shapes of the stressstrain curves for solid polyurethane elastomers with different hard phase contents. It may also be used for low density polyethylene at different temperatures. Yield and rubber crosslink density are given as explanations of departure from ideal elastic behaviour. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.768031 Item 150 Patent Number: US 6008262 A 19991228 FOAMABLE COMPOSITIONS COMPRISING LOW VISCOSITY THERMOPLASTIC MATERIAL COMPRISING AN ETHYLENE ALPHA-OLEFIN McKay K W; Simmons E R; Woodbridge D P Fuller H.B.,Licensing & Financing Inc. These compositions may comprise a single ethylene/ alpha-olefin or a blend thereof and, optionally, at least one diluent including waxes, plasticisers, such as oil, polymeric tackifiers or mixtures thereof. They may be used as cabinet sealants and as foam layers in disposable articles, such as nappies, incontinence devices and medical devices, such as bandages and dressings. USA

Accession no.767704 Item 151 Cellular Polymers 18, No.6, 1999, p.385-401

60

THE THERMAL CONDUCTIVITY OF POLYETHYLENE FOAMS MANUFACTURED BY A NITROGEN SOLUTION PROCESS Almanza O A; Rodriguez-Perez M A; de Saja J A Colombia,University; Valladolid,Universidad Properties of peroxide cross-linked polyethylene foams manufactured by a nitrogen solution process, were examined for thermal conductivity, cellular structure and matrix polymer morphology. Theoretical models were used to determine the relative contributions of each heat transfer mechanism to the total thermal conductivity. Thermal radiation was found to contribute some 22-34% of the total and this was related to the foam’s mean cell structure and the presence of any carbon black filler. There was no clear trend of thermal conductivity with density, but mainly by cell size. 27 refs. COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.765070 Item 152 Innovations in Rotational Molding in the year 2000 and beyond. Conference proceedings. Strongsville, Oh., 6th-8th June 1999, p.95-104 ROTATIONAL FOAM MOULDING OF POLYETHYLENE AND POLYPROPYLENE Pop-Iliev R; Liu G; Liu F; Park C B; D’Uva S; Lefas J A Toronto,University (SPE,Rotational Molding Div.; SPE,Cleveland Section) It is shown how the conventional rotomoulding principle can be used to convert polyolefins into useful foamed articles that can successfully conserve energy and natural resources. A blend of a polyolefin resin and a chemical blowing agent (CBA) is introduced into a mould and the mould is run through a usual four-stage rotomoulding cycle using conventional rotomoulding processing equipment. The selected polyolefin resins are characterised using differential scanning calorimetery. In order to select the most suitable CBAs for foaming of polyolefins, the decomposition behaviour of various CBA candidates is investigated by using thermogravimetric analysis. The CBAs identified in such a way are used to prepare differently formulated PE and PP-based foamable blends, the foaming of which is simultaneously studied using hot-stage optical microscopy and through extensive rotational foam moulding experimental parametric study. A uni-axial, custom-made, lab-scale rotomoulding machine is used for conducting rotational foam moulding experiments. As a result, optimal processing strategies for three- and six-fold expansion foams are identified, and PE and PP foams with reduced cell sizes and increased cell densities are successfully produced. 18 refs. CANADA

Accession no.764439

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 153 Journal of Applied Polymer Science 75, No.1, 3rd Jan.2000, p.156-66 MECHANICAL CHARACTERISATION OF CLOSED-CELL POLYOLEFIN FOAMS Rodriguez-Perez M A; Velasco J I; Arencon D; Almanza O; de Saja J A Valladolid,Universidad; Barcelona,Escola Tecnica Superior d’Enginyers Industrials; Bogota,Universidad de Colombia Three different techniques (compression at low strain rates, falling-weight impact tests and DMA) were used to study a collection of crosslinked (electron beam), closed-cell polyolefin foams of different chemical constitutions, densities, and cellular structures. The thirteen materials were 100% LDPE, LDPE/LLDPE blends, LDPE/EVA blend, EPR/EVA blend, and LDPE/ HDPE blends. Densities ranged from 29 kg/cu.m to 105 kg/cu.m. Some were foamed while passing vertically through an air/IR heated oven (Alveolit), while the others were foamed while passing horizontally through a foaming oven (Alveolen). They were studied by DSC and SEM also. Cells were elongated in the foaming direction. Anisotropy was higher for Alveolit foams than Alveolen foams. 18 refs. COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.764065 Item 154 Journal of Cellular Plastics 35, No.6, Nov./Dec.1999, p.531-49 EXTRUDED NON-CROSSLINKED FOAMS MADE FROM ETHYLENE-STYRENE INTERPOLYMERS AND BLENDS WITH POLYETHYLENE Chaudhary B I; Barry R P Dow Chemical Co.; Dow Deutschland Inc. Ethylene-styrene interpolymers (ESI) are a new class of polymers made by copolymerisation of ethylene and styrene monomers using Insite technology, the patented constrained geometry single site catalysts and proprietary solution process of Dow Chemical. The trade name used for the interpolymers is Index. Foams with novel and unique properties have been made by expanding these polymers using physical blowing agents. The properties of foams made from interpolymers and blends with PE are described. 6 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; USA; WESTERN EUROPE

A process for making a foamed shoe sole includes (a) forming at least one unexpanded blank in at least one first mould by introducing thereinto a resinous moulding composition, which includes an agent capable of expanding and crosslinking the resinous moulding composition, at a temperature lower than that which can cause the composition to expand and cross-link; (b) trimming the unexpanded blank to remove flash and inspecting the weight and size of the unexpanded blank; and (c) placing in a second mould the unexpanded blank having a predetermined weight and size and heating the unexpanded blank under pressure at a temperature high enough to cause the unexpanded blank to undergo expansion and cross-linking, whereby the sole so produced has good cross-linking characteristics and retains exactly the shape and size of the mould cavity of the second mould. Preferably, the resinous composition contains polyethylene vinyl acetate. TAIWAN

Accession no.758880 Item 156 Patent Number: US 5916926 A 19990629 FOAMED HIGH DENSITY POLYETHYLENE Cooper K K; Firdaus V; Poloso A; Tong P P-L Mobil Oil Corp. Control of polyethylene melt strength and melt viscosity has been used to produce foamed articles. USA

Accession no.758259 Item 157 Materiale Plastice 36, No.2, 1999, p.90-5 Rumanian CELLULAR PE PREPARATION BY RADIORETICULATION Zaharescu T; Jipa S; Mitroi M ICPE SA; Arpechim SA PE is suitable for foam manufacture. Azodicarbonamide added in various concentrations, up to 20%, was successfully employed as the blowing agent. The crosslinking of commercial grade material was carried out by exposure to radiation. The expanding temperature was 205C. This study is focused on the functional properties of foams: gel content correlated with expansion ratio, and cell density. 11 refs. EASTERN EUROPE; RUMANIA

Accession no.758031

Accession no.760238 Item 155 Patent Number: US 5972257 A 19991026 PROCESS FOR MAKING A FOAMED SHOE SOLE Liu K-C

© Copyright 2004 Rapra Technology Limited

Item 158 Patent Number: US 5968630 A 19991019 LAMINATE FILM-FOAM FLOORING COMPOSITION Foster S M

61

References and Abstracts

Tenneco Protective Packaging Inc. This is composed of a thin film of LDPE adhered to a sheet of LDPE foam by means of a very thin layer of LDPE. The foam preferably has a density of between about 1.9 and 2.2 pcf and the bottom PE film serves as a vapour barrier. One side of the PE film extends beyond one edge of the PE foam sheet. The laminate composition is installed in a free floating manner on the concrete subflooring, with the PE film or foam sheet contacting the surface of the subflooring. The laminate is usually in long strips so when it is installed one edge of one strip overlies the extended portion of the PE film of an adjacent strip. Tape having adhesive on both sides can be positioned between the overlay region to adhere together the overlaid portions to prevent movement thereof during installation of laminate wood finish flooring, which is installed, in plank form, on top of the laminate composition in a free floating manner. USA

Accession no.756467 Item 159 Patent Number: EP 963827 A2 19991215 MOULDED ARTICLE OF FOAMED AND EXPANDED BEADS OF PROPYLENE RESIN Shioya S; Hira A; Sasaki H; Tokoro H JSP Corp. The moulded article, which has an apparent density of 0.11 to 0.45 g/cu.cm. and an average number of cells within the range of 5 to 100 cells/sq.mm., is obtained by heating and moulding the foamed beads. JAPAN

Accession no.756031 Item 160 Polymer Engineering and Science 39, No.9, Sept.1999, p.1776-86 EXPERIMENTAL STUDY OF FOAMED POLYETHYLENE IN ROTATIONAL MOULDING Liu S-J; Tsai C-H Chang Gung,University Rotational moulding of foamed PE has increasingly become an important process in industry because of its thicker walls, low sound transfer, high stiffness and good thermal insulation. However. the foaming process of polyethylene during rotational moulding has not been well studied. The focus of this article is to assess the rotomouldability of foamed polyethylene and to investigate how blowing agents can influence the process of rotational moulding and the final product quality. Rotational moulding experiments were carried out in a laboratory scale uniaxial machine capable of measuring internal mould temperature in the cycle. Mechanical property tests, as well as thickness distribution and density measurements, were performed on the rotationally moulded parts. Differential scanning calorimetry and

62

optical microscopy have also been employed to identify the material and structural parameters. It was found that the presence of blowing agent results in an improvement of the impact properties, which are counteracted by longer cycle times and uneven surfaces. TAIWAN

Accession no.755472 Item 161 Japan Chemical Week 40, No.2051, 2nd Dec.1999, p.11 JSP ADDING EXPANDABLE PP BEADS PLANT It is briefly reported that, with its factories running at full capacity in the production of expandable PP beads used in core material of automobile bumpers, JSP International recently started building a new plant in Tullahoma, Tennessee. The new plant, with an annual production capacity of 2,800 tons, is scheduled to start operations next July. With a 75% share of the US plastic bumper market, the company is currently capable of producing 14,000 t/y of expandable PP beads. JSP INTERNATIONAL USA

Accession no.754222 Item 162 Asian Plastics News Sept.1999, p.57 DOW DELIVERS CUSTOMISED FOAM TECHNOLOGY Dow Chemical has recently introduced its first customerdefined foam laminate products based on its Index interpolymers, a new family of thermoplastics based on the copolymerisation of ethylene and styrene using Dow’s Insite catalyst technology. Dow’s Envision custom foam laminates allow customers to define virtually any combination of plank or sheet products from Dow’s recently introduced Synergy soft touch foams and its existing line of Ethafoam foam products. The laminates are targeted at OEMs looking to improve case insert designs as well as electronics pack designs. It is also suitable for seat cushions and applications requiring permanent graphic elements. Brief details are noted. DOW CHEMICAL CO. USA

Accession no.753920 Item 163 High Performance Plastics Oct.1999, p.2 NEW PP FOAM DELIVERS 100% PP PERFORMANCE Zotefoams has introduced a new 100% PP foam called Propozote, produced using unique crosslinking technology using an autoclave at a higher temperature

© Copyright 2004 Rapra Technology Limited

References and Abstracts

than usual, and with nitrogen as the expansion agent. The company claims that all other foams on the market at present are actually blends of PP with PE/EVA, and are not able to deliver the full performance benefit of PP. The product is briefly described, and the company’s position as a producer of crosslinked PE block market is indicated. ZOTEFOAMS PLC EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.751706 Item 164 Plastics News International Oct.1999, p.70 PP FOAM FOR INTELLIGENT CAR BATTERY The iQ automotive battery incorporates a micro-chip which monitors and controls the electrochemical process of the lead-acid battery, as well as its physical environmental and operating conditions. The thermal insulation of the battery also plays an important role. Neopolen P, a thermoplastic particle foam from BASF which can be processed completely without blowing agents, was chosen for this application. The foamed battery container calls for a solid frame that can be mounted onto the car body, and this frame is configured as a solid PP injection-moulded article, and fused to the container. BASF AG EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Item 166 Cellular Polymers 18, No.3, 1999, p.197-216 DYNAMIC FATIGUE PROPERTIES OF CLOSED-CELL NON-CROSSLINKED PE FOAMS Sombatsompop N; Saengjun B; Tareelap N; Sudaprasert T King Mongkut’s Institute of Technology Thonburi The dynamic fatigue properties of commercial closedcell/non-crosslinked PE foams were investigated for applications of structural loading and packaging design. The compressive properties were studied in terms of maximum dynamic fatigue stress set at various void sizes, maximum test amplitudes and test speeds, the results being compared with those obtained under static compression conditions. Local temp. rises under cyclic loading and dynamic compression set were also investigated. All the experimental results were obtained using a universal tensile testing machine and the data were recorded using a high speed data logger coupled to a personal computer. The static compressive stress was affected by test speed, but this was not the case for maximum amplitude. These two variables were found to influence the maximum dynamic fatigue stress of the foam in association with increased fatigue in the material, excessive rupture of the cell structure and ductile-brittle characteristics of the foam. 16 refs. THAILAND

Accession no.750959

Accession no.751269 Item 165 Eureka 19, No.9, Oct.1999, p.32-3 FOAMS ARE STRONG ENOUGH TO HOLD UP THE TRAINS Shelley T In the course of developing materials for the building industry, Sekisui Chemical has built up huge experience in developing structural foams. One of its established products is Elson Neo Lumber FFU, a thermosetting PU foam reinforced with long glass fibre, which has been used to make railway sleepers as a replacement for wood. A new honeycomb polyolefin foam is recyclable and much stronger than PS foams. Applications include sound proofing and impact energy absorption in cars. Materials under development include a family of PE and PP foams with compression stiffness optimised in the vertical direction. SEKISUI CHEMICAL (EUROPE) EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.751171

Item 167 Cellular Polymers 18, No.3, 1999, p.157-74 SHEAR AND COMPRESSIVE IMPACT OF POLYPROPYLENE BEAD FOAM Mills N J; Gilchrist A Birmingham,University PP bead foams were subjected to oblique impacts, in which the material was compressed and sheared. This strain combination could occur when a cycle helmet hit a road surface. The results were compared with simple shear tests at low strain rates and to uniaxial compressive tests at impact strain rates. The observed shear hardening was greatest when there was no imposed density increase and practically zero when the angle of impact was less than 15 degrees. The shear hardening appeared to be a unique function of the main tensile extension ratio and was a polymer contribution, whereas the volumetric hardening was due to the isothermal compression of the cell gas. Foam material models for finite element analysis needed to be reformulated to consider the physics of the hardening mechanisms, so their predictions were reliable for foam impacts in which shear occurred. 16 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.750958

© Copyright 2004 Rapra Technology Limited

63

References and Abstracts

Item 168 155th ACS Rubber Division Meeting, Spring 1999. Conference Preprints. Chicago, Il., 13th-16th April 1999, Paper 69, pp.36 OPTIMIZATION OF THE PRODUCTION OF EPDM SPONGE RUBBER SEALS FOR THE AUTOMOTIVE INDUSTRY Krusche A; Haberstroh E IKV (ACS,Rubber Div.) A study was made of relationships between compound rheological properties, microwave vulcanisation parameters and accelerators on the quality of extruded EPDM foam seals for the automotive industry. The influence of these factors on cell size and structure, density and mechanical properties was investigated. Correlations were found between the chemical composition of the compound, variations in processing parameters and the quality of the finished product. 12 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; USA; WESTERN EUROPE

Accession no.749881 Item 169 155th ACS Rubber Division Meeting, Spring 1999. Conference Preprints. Chicago, Il., 13th-16th April 1999, Paper 22, pp.18 HOW TO OPTIMIZE THE PROCESSING OF FOAMED RUBBER GOODS Fuchs E; Reinartz K S Bayer AG (ACS,Rubber Div.) Factors influencing the cell structure and surface appearance of foamed rubber articles are discussed, and results are presented of experiments with EPDM formulations in which interactions between the crosslinking reaction and decomposition of blowing agents were studied. The decomposition reaction was dependent on temperature, and blowing agents differed in their chemical influence on the crosslinking reaction. The rates of decomposition and crosslinking increased with decreasing blowing agent particle size. Synergistic effects were not observed for blends of blowing agents. Decomposition and crosslinking rates could be increased by the addition of zinc dicyanatodiamine, and amounts of zinc oxide determined the activity of the blowing agents and crosslinking. The type of EPDM used affected the crosslinking reaction, but had little or no effect on the decomposition of the blowing agent. 3 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; USA; WESTERN EUROPE

Accession no.749839 Item 170 Antec 99. Volume II. Conference proceedings. New York City, 2nd-6th May 1999, p.2104-8. 012

64

FOAMING OF POLYPROPYLENE IN EXTRUSION PROCESSES Andreassen E; Borve K L; Rommetveit K; Redford K Sintef; Borealis AS (SPE) Various PP grades are foamed using a small generalpurpose twin-screw extruder. Cell diameters of approximately 70 mu and foam densities of approximately 14 kg/cub.m are achieved with a conventional linear PP, using iso-butane as foaming agent. Linear and branched PP grades are subjected to dynamic rheometry and instrumented haul-off measurements, and the results are discussed in terms of melt strength, viscosity and elasticity. Promising results are obtained for branched materials produced by reactive extrusion. 7 refs. NORWAY; SCANDINAVIA; WESTERN EUROPE

Accession no.748781 Item 171 Antec 99. Volume II. Conference proceedings. New York City, 2nd-6th May 1999, p.2100-3. 012 FOAM INJECTION MOULDING OF THERMOPLASTICS LOADED WITH CARBON DIOXIDE PRIOR TO PROCESSING Pfannschmidt O; Michaeli W IKV (SPE) Loading of thermoplastics with CO2 results in a reduction in polymer viscosity. When added in higher concentrations, carbon dioxide allows the production of foams. The addition of carbon dioxide can be realised during processing in the plasticising unit of a special injection moulding machine. However, in the present case the additive is added to the polymer within an autoclave prior to processing with a standard injection moulding machine. Sorption and desorption measurements of carbon dioxide in the polymer are conducted using a magnet suspension balance. The influence of the process parameters on foam structure and density is tested. 6 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.748780 Item 172 Antec 99. Volume II. Conference proceedings. New York City, 2nd-6th May 1999, p.2084-9. 012 STUDY OF SURROUNDING TEMPERATURE EFFECTS ON EXTRUDED FOAM STRUCTURE Lee S T; Lee K Sealed Air Corp. (SPE) Foam extrusion experiments are performed to study the effects of surrounding temperature variation on cell structure. LLDPE is used with endothermic chemical blowing agent on a single-screw extruder to exit from a capillary die into environments with different

© Copyright 2004 Rapra Technology Limited

References and Abstracts

temperatures. Cell density, foam density and cell morphology are investigated. The amount of chemical blowing agent and the surrounding conditions are viewed together to correlate with the cell density. Foam density appears to be related to gas escape from the surface during foaming. 10 refs. USA

Accession no.748777

foams (Alveolen and Alveolux from Sekisui Alveo BV) with different densities, which were obtained from different foaming processes and made of different base polymers, as a function of the treatment temp. and treatment time. The results indicate that the thickness increase of these materials is related to the anisotropic cellular structure of the original foams. 9 refs. SEKISUI ALVEO BV COLOMBIA; EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; SPAIN; WESTERN EUROPE

Item 173 Antec 99. Volume II. Conference proceedings. New York City, 2nd-6th May 1999, p.2071-5. 012 DEVELOPMENTS IN HIGH STRENGTH IPP: TECHNOLOGY PROPERTIES, APPLICATIONS AND MARKETS Ratzsch M; Panzer U; Hesse A; Bucka H Borealis AG (SPE)

Accession no.747389

The manufacture of a new family of high melt strength polypropylenes (HMS-PP), its benefits and application in the field of foam extrusion are discussed. A brief introduction into general pathways of influencing melt strength shows that it is the combination of both, a high strength and high drawability of the polymer melt (due to the introduction of some long-chain branches into the polymer structure) which is the main characteristic of these special materials. The rheological behaviour is due to a special post polymerisation (Daploy) process which introduces long-chain branches into the PP by comonomer bridging. The presentation of general properties resulting from the modified polymer architecture is followed by the discussion of benefits HMS-PP gives to polymer processing and to final material properties. In particular it is possible to manufacture non-crosslinked and thermoformable PP foams with a density range down to 0.1 g/cub.cm and below by PE and PS foam extrusion processes. Main applications are lightweight packaging trays, beakers and containers as well as technical foams for automotive headliners, door liners and acoustic panels. It is shown that the new family of high melt strength PP is a challenge and chance for PP to improve in existing and new polymer applications and markets. 9 refs.

Synergy Soft Touch Foams from Dow Chemical Co. are announced. The products are claimed to be a cost effective and environmentally acceptable alternative to crosslinked PE foams for protective uses. They are made from a proprietary blend of custom-designed low density polyethylene and the company’s Index ethylene-styrene interpolymers. The Synergy foams are made with Dow’s RapidRelease technology, a proprietary process incorporating a patented CFC-free and HCFC-free hydrocarbon blowing agent. Details are given of the materials, the process, applications, and properties. DOW CHEMICAL CO.

AUSTRIA; WESTERN EUROPE

Accession no.748775 Item 174 Journal of Applied Polymer Science 73, No.14, 29th Sept.1999, p.2825-35 ANOMALOUS THICKNESS INCREASE IN CROSSLINKED CLOSED CELL POLYOLEFIN FOAMS DURING HEAT TREATMENTS Rodriguez-Perez M A; Almanza O; De Saja J A Valladolid,Universidad; Columbia,University Results are presented of an experimental study of the thickness increase, change in dimensions and change in properties of a collection of crosslinked closed cell PE

© Copyright 2004 Rapra Technology Limited

Item 175 Modern Plastics International 29, No.9, Sept.1999, p.38/43 DOW UNVEILS SOFT-TOUCH GRADES BASED ON ITS INTERPOLYMERS Darby J

USA

Accession no.745188 Item 176 Patent Number: US 5928584 A 19990727 FOAMABLE COMPOSITIONS FOR ROTATIONAL MOULDING Lee C C; Beuke D T; Feder A R; Lefas J; D’Uva S Wedtech (USA) Inc. These essentially comprise a mixture of a skin-forming component, which comprises two distinct phases blended together, a high zero-shear viscosity material and a low zeroshear viscosity material, and a foam core-foaming component, which includes a blowing agent, physically dry blended together. The three materials are preferably selected from suitable homopolymers and copolymers of ethylene. CANADA

Accession no.744735 Item 177 Patent Number: US 5929127 A 19990727 FINE-CELLED POLYOLEFIN FOAM MATERIALS Raetzsch M; Bucka H; Panzer U; Hesse A; Reichelt N; Leistner D Borealis AG

65

References and Abstracts

These consist of mixtures of PP and polyolefins, which are reacted with bifunctional, unsaturated monomers and/ or hydrolysable, ethylenically unsaturated organosilane compounds in the presence of thermally decomposing free radical-forming agents in two stages and then foamed. They exhibit high dimensional stability at elevated temperatures and high stiffness and have densities ranging from 10 to 600 kg/cu.m. End-uses include food packaging, internal and external automotive parts and electrical/ electronic parts. AUSTRIA; WESTERN EUROPE

Accession no.744583 Item 178 Cellular Polymers 18, No.1, 1999, p.1-20 EFFECT OF BLENDING ON THE PHYSICAL PROPERTIES OF CROSSLINKED CLOSED CELL POLYETHYLENE FOAMS Rodriguez-Perez M A; de Saja J A Valladolid,Universidad The mechanical properties at low strain rates, dynamic mechanical properties, creep-recovery behaviour, thermal expansion and thermal conductivity of foams manufactured from blends of LDPE with an EVA and with an isoprene-styrene block copolymer were studied as a function of the LDPE content in the blends. The experimental results demonstrated important aspects related to the modification of the foam properties by blending. 16 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.744011 Item 179 European Plastics News 26, No.7, July/Aug.1999, p.43 MATT EVAS AIMED AT SHOE MARKETS API has launched Apifive, a new line of crosslinked, expanded EVAs that, unlike conventional EVAs, have a matt finish. API has developed these new products by introducing a series of elastomers into the EVAs, it is briefly reported. The compounds are especially suitable for insoles, where the requirements are for matt, very soft and dimensionally constant parts, and for quality soles for mounting or milling. API SPA EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.743096 Item 180 Packaging Magazine 2, No.12, 17th June 1999, p.26 FOAM’S A SOFT TOUCH

66

Dow Chemical has launched a range of foams which are said to exceed industry standards for softness and toughness. This article supplies brief details of the foams which are based on Dow’s Insite catalyst technology. Synergy Soft Touch Foams are produced using Dow’s Index Interpolymers, a new thermoplastic polymer family based on the copolymerisation of ethylene and styrene. The foams are offered in three grades of softness, and other properties include shock absorption, vibration damping and insulation. DOW CHEMICAL CORP. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.742244 Item 181 Canadian Plastics 57, No.5, May 1999, p.40 FOAMS MEET PACKAGING REQUIREMENTS The Sealed Air Corp. has introduced Stratocell laminated polyethylene foam plank and CelluPlank polyethylene foam. These foams are designed to meet a range of protective packaging requirements from economical lightweight protection to heavy duty industrial cushioning applications. The high performance cushioning provided allows package designers to get the same, or better, protective results using fewer cubic feet per pack and eliminating waste costs. Stratocell is a multilayer plank of 1/2in. thick layers ranging from 1in. to 5in. in thickness. CelluPlank polyethylene foam is perfect for heavier applications requiring shock absorption, vibration damping, thermal insulation or sound deadening. This abstract includes all the information contained in the original article. SEALED AIR CORP. CANADA

Accession no.742235 Item 182 Asian Chemical News 5, No.224, 12th July 1999, p.7 DOW KEEPS QUIET WITH INDEX FOAMS Dow has developed a metallocene-based ethylene-styrene foam interpolymer using Index technology, which is claimed to provide significant advances in sound insulation. Quash dB1 Sound Management Foam is produced by a rapid Release Technology, the company’s patented CFC-free, HCFC-fee, and HFC-free blowing agent system, together with an accelerated curing systems which is claimed to reduce residual blowing agents in the foam to trace levels. Applications for the Quash foams are indicated. DOW USA

Accession no.740709

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 183 Patent Number: EP 928805 A2 19990714 PROCESS FOR MAKING FOAM ARTICLES FROM HIGH MELT STRENGTH PROPYLENE POLYMER MATERIALS Bavaro V P Montell North America Inc.

PE extrudates, are combined with physical atmospheric blowing agents, such as nitrogen, argon, carbon dioxide, water and blends thereof, to produce uncrosslinked foams having densities as low as 10 kg/cu.cm. USA

Accession no.738737

A material, such as (a) a terpolymer of propylene, ethylene and butene-1, (b) a polyolefin composition, which includes about 31 to 39% of a copolymer of propylene and ethylene and about 58 to 72% of a terpolymer of propylene, ethylene and butene-1 or (c) a polyolefin composition, which includes about 30 to 65% of a copolymer of propylene and butene-1 and about 35 to 70% of a copolymer of propylene and ethylene, is irradiated and extruded through a die in the presence of a physical expanding agent and a cell nucleating agent to produce a structure having a density, which is at least 10 times less than the initial density of the material. The foam articles exhibit improved flexibility and low temperature toughness compared to conventional propylene polymer materials.

Item 186 Patent Number: US 5902858 A 19990511 MODIFIED POLYPROPYLENE RESIN, FOAM MADE THEREOF AND PROCESSES FOR THE PREPARATION OF THEM Okura T; Miyama O; Tomita H Kaneka Corp.

USA

Accession no.738698

The PP is produced by melt-kneading PP, an isoprene monomer and a radical polymerisation initiator, which has a high melt viscosity and a high melt tensile strength and is difficult to cause drawdown. Foamed articles made therefrom have a low density, high closed cell content, good appearance and excellent heat resistance. JAPAN

Accession no.740001 Item 184 Popular Plastics and Packaging 44,,No.5, May 1999, p.71-3 THIN FOAMS OF LDPE Singh P; Singh H; Gupta A Shiram Institute for Industrial Research

Item 187 Patent Number: US 5783611 A 19980721 COMPOSITION AND PROCESS FOR ROTATIONAL MOULDING FOAMED ARTICLES Strebel J J Millennium Petrochemicals Inc.

The production of LDPE thin foams is discussed, and its superior properties as compared with polystyrene are examined. The radiation crosslinking of LDPE foams is the preferred method for thin foams and chemical crosslinking for thicker foams. Work on the development of compositions for making thin foams of LDPE was initiated at Shiram Institute, whereby various compositions of LDPE were designed and formulated by incorporating various amounts of blowing agents, resin lubricants and nucleating agents. Test results are briefly examined with respect to density and gel content. 15 refs.

Improved compositions useful for the production of foamed rotomoulded articles are provided. The compositions of the invention are comprised of a first thermoplastic resin component which is an ethylene polymer in pellet form containing a foaming agent and a second thermoplastic resin component which is a powder consisting of a mixture of different particle size and melt index ethylene polymers. An improved process for producing foamed rotomoulded articles having uniformly foamed interiors and smooth exterior skins which are substantially free of surface defects is also provided.

INDIA

USA

Accession no.739884

Accession no.737307

Item 185 Patent Number: US 5905098 A 19990518 PROCESS FOR PRODUCING LOW DENSITY POLYETHYLENIC FOAM WITH ATMOSPHERIC GASES AND POLYGLYCOLS OR POLYGLYCOL ETHERS Wilkes G R; Dunbar H A; Bly K A; Uhl E R Tenneco Protective Packaging Inc.

Item 188 Patent Number: EP 916465 A1 19990519 COMPOSITE POLYPROPYLENE MATERIAL HAVING MOULDED AND FOAMED LAYER AND METHOD OF PRODUCING SAME Shioya S; Shinohara M; Tokoro H JSP Corp.

Polyglycols or polyglycol ethers, which have gas absorption properties and exhibit a plasticising effect in

© Copyright 2004 Rapra Technology Limited

This composite material includes a PP moulded body having a particular melting point and a foamed body of expanded particles fuse-bonded to the body, which is

67

References and Abstracts

placed in the mould prior to moulding the composite. The foamed body has at least two endothermic peaks in the DSC curve thereof at peak temperatures of 135C or more. The peel strength between the moulded body and the foamed body is at least 1.5 kg/15 mm. JAPAN

Accession no.736038 Item 189 Patent Number: US 5883145 A 19990316 CROSSLINKED FOAM STRUCTURES OF POLYOLEFINS AND PROCESS FOR MANUFACTURING Hurley R F; Kozma M L; Feichtinger K A Sentinel Products Corp. Disclosed are crosslinked foam compositions utilising polyolefins, which are essentially linear and comprise ethylene polymerised with at least one alpha-unsaturated C3 to C20 olefinic comonomer and, optionally, at least one C3 to C20 polyene. The copolymers have a density in the range of about 0.86 to 0.96 g/cu.cm., a melt index in the range of about 0.5 to 100 dg/min, a MWD in the range of from about 1.5 to 3.5 and a composition distribution breadth index greater than about 45%. The compositions exhibit improved strength, toughness, flexibility, heat resistance and heat sealing temperature ranges, as compared to conventional LDPE compositions. They also exhibit processing improvements over LLDPE. USA

Accession no.735949 Item 190 Patent Number: US 5883144 A 19990316 SILANE-GRAFTED MATERIALS FOR SOLID AND FOAM APPLICATIONS Bambara J D; Kozma M L; Hurley R F Sentinel Products Corp. Disclosed are polyolefins, which are essentially linear and comprise ethylene polymerised with at least one alphaunsaturated C3 to C20 olefinic comonomer and, optionally, at least one C3 to C20 polyene, and exhibit a density in the range of about 0.86 to 0.96 g/cu.cm., a melt index in the range of about 0.5 to 100 dg/min, a MWD in the range of from about 1.5 to 3.5 and a composition distribution breadth index greater than about 45%. The polyolefins are silane grafted to enhance physical properties and processability and are used to make crosslinked foam compositions having improved strength, toughness, flexibility, heat resistance and heat sealing temperature ranges, as compared to conventional LDPE compositions. They also exhibit processing improvements over LLDPE. USA

Accession no.735948

68

Item 191 Antec 99.Volume 1.Conference proceedings. New York City, 2nd-6th May, 1999, p.1457-67.012 COMPARISON OF DRYING BLENDING-BASED AND MELT COMPOUNDING-BASED ROTOMOLDING TECHNIQUES FOR LLDPE FOAMS Pop-Iliev R; Liu G; Liu F; Park C B; D’Uva S; Lefas J A Toronto,University; WedTech Inc. (SPE) A chemical blowing agent was well dispersed in a linear low density polyethylene matrix, in pellet form. The pellets were rotationally moulded to produce foams, the morphology of the foams being studied using optical microscopy. The quality of the cell structures in terms of cell size, cell population density and volume expansion ratio was superior to that of foams produced by drying blending. 28 refs. CANADA

Accession no.735496 Item 192 4th Rotamoulding Conference. Conference proceedings. London, 1995, paper 1. 835 NEW DEVELOPMENTS IN ROTATIONAL MOULDING Roels W Borealis AS (BPF) This paper takes the form of overhead slides which discuss the foaming of polyethylene in rotational moulding. Discussed are the characteristics of PE foam, its applications and processing, physical properties, one-shot foam, and a third generation rotational moulding grades with improved flow properties. NORWAY; SCANDINAVIA; WESTERN EUROPE

Accession no.730323 Item 193 Espoo, Technical Research of Finland, 1998, pp.103. 10 ins. 15/4/99. VTT Publn. 361 NEW TECHNOLOGY TO MANUFACTURE POLYPROPYLENE FOAM SHEET AND BIAXIALLY ORIENTED FOAM FILM Raukola J I VTT Chemical Technology VTT Publn.361 A new three-layer blown film die design was developed to produce foamed tube and biaxially oriented PP film. Testing was carried out on homopolymer, bimodal polymer and copolymer types of PP. The study addresses extrusion conditions, including screw and die designs; the effects of chemical foam nucleating agents; the effects of processing parameters on foam structure; and rheological properties. In addition, some applications

© Copyright 2004 Rapra Technology Limited

References and Abstracts

leading to new commercialised innovations in foam films are discussed. 78 refs. FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.729790 Item 194 Materie Plastiche ed Elastomeri No.9, Sept.1998, p.550-4 Italian EXTRUSION AND THERMOFORMING OF RIGID PP FOAM PACKAGING Terragni F Italproducts srl Details are given of extrusion and thermoforming lines developed by Italproducts for the manufacture of PP foam containers. The extrusion process using high melt strength PP and chemical blowing agents is described and results are presented of thermoformability studies. REEDY INTERNATIONAL CORP. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.726318 Item 195 Kunststoffe Plast Europe 89, No.3, March 1999, p.24-6. (Translated from Kunststoffe 89 (1999) 3, pp.78-80) DASHBOARD MODULE FROM PP Johannboke E; Popp G Peguform GmbH The design and manufacture is described in detail of a dashboard module from polypropylene. The lightweight monomaterial dashboard comprises an outer material of a TPO film, foam backed with an EPP foam. This decorative element, together with a highly integrated composite fibre hybrid cross beam, forms the core element of the lightweight dashboard module. The prototype consists of four individual components, and is designed in such a way that it can be built into and tested in the Mercedes A class car. 3 refs. JSP INTERNATIONAL EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.726049 Item 196 Tech XXI. Conference proceedings. Orlando, Fl., 6th-8th May,1998, p.111-24. 6A7 PERFORMANCE BENEFITS OF FLEXIBLE METALLOCENE FOAMS IN PRESSURE SENSITIVE TAPE APPLICATIONS Smith S C Sentinel Products Corp. (Pressure Sensitive Tape Council)

© Copyright 2004 Rapra Technology Limited

The traditional production and applications of crosslinked polyolefin foams is reviewed and the advantages of polyolefins produced by metallocene catalysts is pointed out. They can be crosslinked by silanes to give uniform materials. Densities can be half and strengths double those of conventional foams. As adhesive tapes they can be used as adhesive carriers and facilitators in bonding of dissimilar and non-uniform surfaces. Examples are double faced mounting tapes, EKG pads and use in attaching body side mouldings in cars. CMR (Continuous Metallocene Rubber from Sentinel Products Corp.) is a roll product of 100% elastomeric metallocene polymer. EMR (Elastomeric Metallocene Rubber from Sentinel Products Corp.) is a bun product that contains over 50% elastomeric metallocene polymers. Of the three products from Sentinel Products Corp. it exhibits the greatest elastomeric properties as well as superior thermoforming properties. MPO (Metallocene Polyolefin Blend from Sentinel Products Corp.) is a blend of elastomeric metallocene with conventional polyolefins. It is designed to bridge the gap between PVC foams and conventional PE foams. Currently it has replaced a significant share of EVAc adhesive tape foams and PVC foams. Considerable data are shown to explain the technology and the materials’ advantages over conventional crosslinked polyolefin, cellular neoprene, cellular EPDM, cellular SBR and cellular NBR/PVC blend. Peel strength data compares peel adhesion on steel for competitive PE foam and Sentinel MPO. Brief food contact and toxicity information is included. USA

Accession no.724129 Item 197 Patent Number: US 5859076 A 19990112 OPEN CELL FOAMED ARTICLES INCLUDING SILANE-GRAFTED POLYOLEFIN RESINS Kozma M L; Bambara J D; Hurley R F Sentinel Products Corp. Describes open cell foamed articles including silanegrafted single-site initiated polyolefin resins. The olefin polymer resin can be a polyethylene, a copolymer of ethylene, a C3-C20 alpha-olefin, or a copolymer of ethylene, a C3-20 alpha-olefin and a C4-C20 diene. The open cell foamed articles have good cushioning properties and can be non-allergenic. USA

Accession no.721176 Item 198 Polymer Engineering and Science 38, No.12, Dec.1998, p.1997-2009 PRODUCTION OF LOW DENSITY LLDPE FOAMS IN ROTATIONAL MOULDING Liu G; Park C B; Lefas J A Toronto,University; WedTech Inc.

69

References and Abstracts

In order to better understand the mechanisms of foaming, a fundamental study on the foaming process in rotomoulding was conducted. First, the decomposition behaviour of the chemical blowing agents, sodium bicarbonate and Celogen OT (p,p’oxybisbenzenesulphonyl hydrazide from Uniroyal Chemicals) was studied by TGA. The zero-shear viscosity of LLDPEs was measured using a rotational stress rheometer. Also, an optical microscope with a hot stage was used to study cell nucleation, growth, coalescence, and coarsening in LLDPE melts, which provide an improved understanding of the foaming dynamics with a chemical blowing agent in rotational moulding. Finally, the actual foaming behaviour in rotomoulding was studied. The experimental results indicate that the amount of blowing agent, the heating time, and the processing temperature play important roles in determining the cell morphology in rotational foam moulding. 23 refs.

Item 201 Patent Number: US 5837173 A 19981117 PROCESS FOR PREPARING EXPANDED ARTICLES BASED ON CHLOROTRIFLUOROETHYLENE COPOLYMERS Vita G; Pozzoli M Ausimont SpA A copolymer of ethylene and chlorotrifluoroethylene is mixed with 0.5 to 2 wt.% of boron nitride, the blend obtained is extruded at 260 to 300C, nitrogen is injected into the blend at 50 to 150 atmospheres and the pressure is lowered to produce the expanded article, which has high dielectric properties. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.716611

CANADA

Accession no.718716 Item 199 Patent Number: EP 896020 A1 19990210 PROCESS FOR THE PREPARATION OF A SUPER LIGHTWEIGHT FOAMED SHEET Moon H S; Cattan E D A LDPE, a first blowing agent, a surfactant and a separation agent are mixed and the resulting mixture is heated at a temperature higher than 160C to obtain a molten mass, which is then heated at a temperature higher than the gasification temperature of the blowing agent to separate the blowing agent. The mixture is then cooled and formed into a sheet. A second gaseous blowing agent is introduced into the cooled mass, the foamed mass obtained is maintained at a stabilising temperature to stabilise it and cooled at 20 to 25C and the resulting cooled mass is maintained at this temperature for 24 hours. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; KOREA; WESTERN EUROPE

Item 202 Patent Number: US 5801208 A 19980901 BLOWING AGENT, EXPANDABLE COMPOSITION, AND PROCESS FOR EXTRUDED THERMOPLASTIC FOAMS Shau-Tarng Lee Sealed Air Corp. An expandable thermoplastic composition is disclosed for extrusion foaming wherein the composition comprises a polyethylene resin and a blowing agent comprising ethane present in an amount of at least about 40 percent or more by weight based upon the total weight of the blowing agent and a different alkane selected from the group consisting of C1, C2, C3, C4, C5 and C6 alkanes and mixtures thereof, wherein the minimum percentage of ethane increases above 40 percent as the arithmetic mean carbon number of the different alkane increases from 3 to 5. A process for extrusion foaming of the composition is also disclosed. USA

Accession no.718549

Accession no.714255

Item 200 Patent Number: US 5844009 A 19981201 CROSSLINKED LOW-DENSITY POLYMER FOAM Hurley R F; Bambara J D; Bambara M; Bambara R Sentinel Products Corp.

Item 203 Plasticheskie Massy (USSR) No.9, 1997, p.37-40 Russian STUDY OF THE PROCESS OF FOAMING OF POLYMER MELTS Markov A V; Kuleznev V N; Vlasov S V; Salman I A; Zavgorodnii V V Moscow,Institute of Fine Chemical Technology

This is a blend of LDPE, which generally has a density between 0.91 and about 0.93 g/cu.cm. and a melt index greater than 1 and a silane-grafted single-site initiated polyolefin, which is generally a copolymer of ethylene and a C3 to C20 alpha-olefin having a density between about 0.86 and 0.96 g/cu.cm. and a MWD between about 1.5 and 3.5. USA

Accession no.718351

70

A study is described of the kinetic dependencies of the solution and separation of gases and of their solubility in melts of polymers under real conditions, in order to obtain the appropriate conditions for the formation of the required porous structure. The materials investigated were compositions based on polyethylene, polypropylene,

© Copyright 2004 Rapra Technology Limited

References and Abstracts

polystyrene, and poly(methyl methacrylate) containing the chemical blowing agent azadicarbonamide Chkh-21. 8 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. RUSSIA

Accession no.713965 Item 204 Cellular Polymers 17, No.5, 1998, p.309-26 CHALLENGE TO THE PRODUCTION OF LOWDENSITY, FINE-CELL HDPE FOAMS USING CARBON DIOXIDE Behravesh A H; Park C B; Venter R D Toronto,University The manufacture of low-density, fine-cell HDPE foams by extrusion using carbon dioxide as a blowing agent was investigated. The strategies adopted to produce lowdensity, fine-cell HDPE foams were to generate a large number of cells by a rapid pressure drop, to suppress cell coalescence by strengthening the melt via melt temp. control and to promote expansion by cooling the extrudate surface and blocking the gas escape. A continuous extrusion process was designed and implemented on the basis of these strategies. The concept of promoting large expansion while preventing cell coalescence to maintain a high cell density was successfully demonstrated through experiments. Low-density, fine-cell HDPE foams were produced with an expansion ratio in the range 1.5 to 20 times, a cell density of the order of 100,000,000 cells/cc and a cell size of the order of 50 micrometres. 29 refs. CANADA

Accession no.713471 Item 205 Patent Number: US 5817705 A 19981006 SHORT TIME FRAME PROCESS FOR PRODUCING EXTRUDED CLOSED CELL LOW DENSITY PROPYLENE POLYMER FOAMS Wilkes G R; Stimler J J; Bly K A; Dunbar H A; Uhl E R Tenneco Protective Packaging Inc. A propylene polymer or copolymer or a blend thereof, which exhibits sufficient strain hardening, viscoelastic behaviour and melt ductility, is heated, melted and mixed in an extruder with an organic or inorganic physical blowing agent or a mixture of organic and inorganic physical blowing agents and optional compatibilisers, nucleating agents, stabilisers and miscellaneous additives. This mixture is pressurised and then cooled at elevated pressure, extruded through a die at rates in excess of 1,000 kg/hr to produce an expanded and dimensionally stable, predominantly closed-cell propylene polymer foam having a density of between 10 and 150 kg/cu.cm. and a thickness in excess of 1.3 cm. The foams have a

© Copyright 2004 Rapra Technology Limited

foamability index greater than 1.9 and a specified ebullation time. USA

Accession no.710316 Item 206 Cellular Polymers 17, No.4, 1998, p.252-70 EXPERIMENTS AND MODELLING OF THE EXPANSION OF CROSSLINKED POLYETHYLENE FOAMS Mahapatro A; Mills N J; Sims G L A Manchester,University; UMIST The density of chemically-blown LDPE foam was altered by varying the amount of blowing agent, degree of crosslinking of the polymer, and the foam expansion temperature. A theory was proposed for the equilibrium density, based on the gas pressures in a Kelvin foam structure, and a rubber-elastic analysis of the biaxial stretching of the cell faces. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.705277 Item 207 Cellular Polymers 17, No.4, 1998, p.221-51 EFFECT OF TALC ON CELL NUCLEATION IN EXTRUSION FOAM PROCESSING OF POLYPROPYLENE WITH CARBON DIOXIDE AND ISOPENTANE Park C B; Cheung L K; Seung-Won Song Toronto,University The effect of talc on the cell density of extruded foams was investigated when carbon dioxide or isopentane was used as blowing agent. The critical materials and processing parameters that affect PP foam morphology were identified: the effects of type and concentration of blowing agent, processing pressure, and pressure drop rate on the foam structure were examined. In particular, nucleation behaviour with talc for volatile carbon dioxide was clearly contrasted with the nucleation behaviour for a long-chain blowing agent isopentane. 32 refs. CANADA

Accession no.705276 Item 208 Patent Number: US 5776993 A 19980707 THERMOPLASTIC PVC FOAM COMPOSITION Bong Sub Shin; Jae Yeon Lee; Dong Keun Kim; Seoun Jun Kim; Sung Ok Cho Korea,Institute of Footwear & Leather Technology; HS Corp. This invention relates to a thermoplastic foam composition and more particularly to the thermoplastic

71

References and Abstracts

PVC foam composition suitable for a shoe material, which is characterised by the following fabrication and advantages. Some plasticiser and additive are added to the PVC base, plasticised by dioctyl phthalate or epoxide soybean oil to obtain the thermoplastic PVC foam composition. Then one type of compound, selected from a rubber thermoplastic compound and ethylene vinyl acetate copolymer, was added to the mixture for modification. The desired product, so formed, has certain advantages such as (a) possible foaming by extruder and injector, including heating press; (b) the composition, so foamed, can be regenerated; (c) the desired product is lightweight, due to its low specific gravity, and (d) its physical properties, anti-slip, abrasion resistance and adhesion to other materials are remarkable. KOREA

Accession no.704680 Item 209 Patent Number: EP 872516 A1 19981021 FOAMABLE POLYMERIC COMPOSITION Brzoskowski R; Sadeghi R; Wang Y DSM NV This comprises a thermoplastic elastomer based on a polyolefin and a rubber. The polyolefin is a PP homo- or copolymer having a specified weight-average molec.wt. and elongational viscosity (measured at a temperature of 170C, a rate of elongation of 0.03 1/s and at a time of 10 s). EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.701309 Item 210 Journal of Polymer Science : Polymer Physics Edition 36, No.14, Oct.1998, p.2587-96 THERMAL EXPANSION OF CROSSLINKED CLOSED-CELL POLYETHYLENE FOAMS Rodriguez-Perez M A; Alonso O; Duijsens A; de Saja J A Valladolid,Universidad; Sekisui Alveo BV Crosslinked low-density polyethylene foams with a closedcell structure were investigated using differential scanning calorimetry, scanning electron microscopy, density, and thermal expansion measurements. At room temperature, the coefficient of thermal expansion decreased as the density increased. This was attributed to the influence of gas expansion within the cells. At a given material density, the expansion increased as the cell size became smaller. At higher temperatures, the relationship between thermal expansion and density was more complex, due to physical transitions in the matrix polymer. Materials with high density and thick cell walls were concluded to be the best for low expansion applications. 16 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; SPAIN; WESTERN EUROPE

Item 211 Patent Number: US 5747549 A 19980505 FOAMED PARTICLES OF POLYPROPYLENE HOMOPOLYMER AND MOULDED ARTICLE OF THE FOAMED PARTICLES Tsurugai K; Tokoro H; Oikawa M JSP Corp. The moulded articles of foamed particles composed of a polypropylene-based polymer, have had excellent cushioning characteristics and impact resilience, but have not always been satisfactory in stiffness such as compressive strength. The invention is directed to foamed particles comprising a polypropylene homopolymer as a base resin and having a tensile modulus of 15000-25000 kg/sq.cm. and a crystal structure that an inherent peak and a high-temperature peak appear as endothermic peaks on a DSC curve. A moulded article of foamed particles is obtained by using the foamed particles as described above and moulding them, and has a density of 0.01-0.3 g/cu.cm. and a tensile modulus of 15000-25000 kg/sq.cm. It has a crystal structure that an inherent peak and a hightemperature peak appear on a DSC curve obtained by its differential scanning calorimetry like the case of the foamed particles. As with the foamed particles, a quantity of heat at the high-temperature peak is 30-60 J/g. JAPAN

Accession no.698637 Item 212 Patent Number: US 5744231 A 19980428 COMPOSITE FOAM MOLDED ARTICLE, PROCESS FOR PRODUCTION THEREOF COMPOSITION Igarashi T; Shinohara S; Tatsumi M; Hikasa T; Mendori H Sumitomo Chemical Co.Ltd. An integrally moulded composite article comprised of (I) a nonfoam layer formed from a thermoplastic elastomer powder composition (A) and (II) a foam layer formed from a foamable composition comprised of (i) (B) a thermoplastic synthetic resin powder, and (C) a heat decomposable foaming agent and (D) a liquid coating agent, wherein the thermoplastic elastomer powder (A) is comprised of a composition of an ethylene-alpha-olefin copolymer rubber and a polyolefin resin or thermoplastic elastomer powder comprised of a partially crosslinked composition of an ethylene-alpha-olefin copolymer rubber and a polyolefin resin, the thermoplastic elastomer powder having a complex dynamic viscosity at 250 deg C and a frequency of 1 radian/sec of not more than 1.5 x 1,000,000 poise and having a Newtonian viscosity index n, calculated by a specific formula. JAPAN

Accession no.697122

Accession no.699627

72

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 213 Cellular Polymers IV. Conference proceedings.. Shawbury, 5th-6th June, 1997, paper 15. 6124 DEFORMATION MECHANISMS IN LDPE CLOSED CELL FOAMS Mills N J; Gilchrist A Birmingham,University (Rapra Technology Ltd.) The effect of gas compression on the uniaxial compression stress-strain curve of closed-cell polymer foams was analysed. The elastic contribution of cell faces to the compressive stress-strain curve is predicted quantitatively, and the effect on the initial Young’s modulus is said to be large. The polymer contribution was analysed using a tetrakaidecahedral cell model. It is demonstrated that the cell faces contribute linearly to the Young’s modulus, but compressive yielding involves non-linear viscoelastic deformation. 3 refs.

properties and in particular the impact strength of the blends were significantly improved by foaming. 45 refs. CANADA

Accession no.694916 Item 216 International Polymer Processing 13, No.2, July 1998, p.129-35 GENERATION OF PARTIALLY CROSSLINKED EXPANDED PP FILMS AND SHEETS Fritz H G; Bolz U; Lu R Stuttgart,University A modified concept for the generation of partially crosslinked expanded PP films and sheets for use in automotive applications is presented. An optimised formulation window for the organosilane crosslinking of selected PP copolymers is described in detail. 5 refs.

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.696332

Accession no.694266

Item 214 Eureka 18, No.9, Sept.1998, p.48 ENGINEERED FOAM PUTS AN END TO BREAKAGES

Item 217 Antec 98. Volume III. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.3527-32. 012 SHEAR AND PRESSURE EFFECTS ON EXTRUDED FOAM NUCLEATION Lee S-T; Kim Y Sealed Air Corp. (SPE)

A leading maker of audio mixing desks wanted a packaging solution which used end caps to protect its equipment. Sealed Air’s Stratocell PE foam is elastomeric so can be engineered with hinges, dovetail latches and expanding concertina sections. The mixing desk end caps could be made in a form which opened out using hinges, so that the desk could be placed in them from above. They may then be closed and latched together. SEALED AIR LTD. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.695835 Item 215 Polymer Engineering and Science 38, No.7, July 1998, p.1205-15 PROCESSING AND CHARACTERISATION OF MICROCELLULAR FOAMED HIGH-DENSITY POLYETHYLENE/ISOTACTIC POLYPROPYLENE BLENDS Doroudiani S; Park C B; Kortschot M T Toronto,University A study on the batch processing and characterisation of microcellular foamed HDPE/isotactic PP blends is reported. The blends were used to produce materials with a variety of crystalline and phase morphologies to enhance the subsequent microcellular foaming. Much finer and more uniform foams were produced with the blends than with neat HDPE and isotactic PP. The mechanical

© Copyright 2004 Rapra Technology Limited

Results of LDPE foam nucleation tests using a counterrotating twin-screw extruder equipped with a rod die are presented. The foam rod shows increased cell nucleation closer to skin compared to the centre area. The effects of throughput rate and corresponding shear rate and pressure drop are correlated. According to viscoelastic flow measurements in the rod die, its surface experiences higher shear over the centre, the nucleation of which is primarily pressure gradient-controlled. Cell nucleation density appears to be more sensitive to shear variation than to pressure gradient. A cavity model is used to describe the nucleation phenomena. 15 refs. USA

Accession no.693727 Item 218 Journal of Macromolecular Science A A35, Nos.7&8, 1998, p.1147-58 MORPHOLOGY AND ORIENTATION OF PPSTRUCTURAL FOAM MOULDINGS Djoumaliisky S; Christova D; Touleshkov N; Nedkov E Bulgarian Academy of Sciences Details are given of the interaction between the macrostructure and morphology of PP structural foam mouldings made by the gas-counter pressure process. The morphology, orientation, and processes of non-isothermal

73

References and Abstracts

phase transition were studied using polarised optical microscopy, light scattering, DSC and birefringence. 12 refs. BULGARIA; EASTERN EUROPE

Accession no.689383 Item 219 Journal of Macromolecular Science A A35, Nos.7&8, 1998, p.1127-35 MORPHOLOGY OF PE FOAMED CROSSLINKED SPECIMENS MADE BY HOT MOULD INJECTION MOULDING Kotzev G; Touleshkov N; Christova D; Nedkov E Bulgarian Academy of Sciences Foamed and crosslinked specimens of PE made by hot mould injection moulding were investigated. The degree of crosslinking was calculated by equilibrium strain determined at 140C. The degree of crystallinity was determined by DSC-kinetics of a nonisothermal melting and crystallisation. Morphology was investigated by polarised microscopy. 3 refs.

side of the foamed sheet before the sheet cools to solidify and press moulding the cover sheet on the foamed sheet to cover. There is also provided an automotive moulded roof material produced by the above process. An automotive moulded roof material is obtained which can be recycled, is lightweight and has high rigidity. JAPAN

Accession no.688197 Item 222 Cellular Polymers 17, No.2, 1998, p.93-113 USE OF ONLINE RHEOMETRY TO CHARACTERISE POLYMER MELTS CONTAINING PHYSICAL BLOWING AGENTS Gendron R; Correa A Canada,National Research Council; Rheometric Scientific Inc.

These comprise at least one homogeneously branched ethylene polymer and at least one blowing agent. They are particularly suitable for sealing food and liquid containers and do not contribute to taste and/or odour of the packaged product.

The application of online rheometry is considered with particular reference to polymer melts plasticised by physical blowing agents. Experimental investigations are performed on PS containing 0-15 wt.% of HCFC-142b or HFC-134a or 0-5 wt.% of carbon dioxide at various temperatures and shear rates. It is shown that the results could be used to indicate the solubility limit and related to the glass transition temperature. Rheological modelling and data fits are compared indicating that a time/ temperature composition (i.e. relative concentrations of polymers/blowing agent mixtures) superposition principle is valid. The model is extended to consider effects using a semi-crystalline polymer (PP). It is concluded that an online return-to-stream process control rheometer can satisfactorily measure and monitor mixtures of polymers and physical blowing agents used in thermoplastic foam extrusion. Appropriate viscosity measurements can be directly linked to a number of critical variables. 13 refs.

USA

CANADA; USA

Accession no.688241

Accession no.688007

Item 221 Patent Number: US 5656675 A 19970812 AUTOMOTIVE MOLDED ROOF MATERIAL AND PROCESS FOR PRODUCING THE SAME Kobayashi T; Morita K; Suzuki S Mitsui Petrochemical Industries Ltd.

Item 223 Antec 98. Volume II. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.1987-900. 012 COMPRESSIVE STRESS RELAXATION OF CLOSED-CELL, METALLOCENE-BASED POLYOLEFIN FOAMS Bhatt C U; Hwang C R; Khan S A North Carolina,State University; Becton,Dickinson & Co. (SPE)

BULGARIA; EASTERN EUROPE

Accession no.689381 Item 220 Patent Number: US 5723507 A 19980303 FORMED GASKETS MADE FROM HOMOGENEOUS OLEFIN POLYMERS Markovich R P; Whetten A R Dow Chemical Co.

A process for producing an automotive moulded roof material is provided which comprises sheeting a foamable sheet forming composition comprising a specified propylene resin, a glass fibre, a radical initiator, a crosslinking auxiliary and a foaming agent in specific proportions into a foamable sheet, lining one side of the foamable sheet with a backing sheet so as to integrate these and irradiating the foamable sheet with ionising radiation to thereby crosslink the propylene resin, followed by heating the foamable sheet so as to cause the foamable sheet to foam, placing a cover sheet on the other

74

Closed-cell foams made from metallocene-based polyolefins (MPO) have potential for use in various applications because of their uniform composition and low toxicity. Compressive stress relaxation is used to investigate the behaviour of these foams. In particular, its behaviour is compared with open-cell PU foams, a material MPO foams could possibly replace. The effect of gamma radiation on MPO foam behaviour is also

© Copyright 2004 Rapra Technology Limited

References and Abstracts

investigated. Step strain experiments reveal PU foam to have an equilibrium relaxation modulus, whereas the nonradiated MPO exhibits complete stress relaxation. Radiation under vacuum, however, induces crosslinking in the polyolefin to improve structural stability and stress relaxation behaviour of the MPO foams significantly. The presence of oxygen during radiation is detrimental as it impedes the crosslinking process. 9 refs.

Item 226 Antec 98. Volume II. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.1822-31. 012 ROTATIONAL MOULDING OF LOW-DENSITY LLDPE FOAMS Liu G; Park C B; Lefas J A Toronto,University; WedTech Inc. (SPE)

USA

Plastic foam processing for the manufacture of LLDPE foams in rotomoulding is presented. In order to better understand the mechanisms of foaming, a fundamental study on the foaming process in rotomoulding is conducted. First, the decomposition behaviour of the chemical blowing agents is studied by thermogravimetric analysis (TGA). The rheological properties of zero-shear viscosity and melt elasticity for LLDPEs are measured using a rotational stress rheometer. Also, an optical microscope with a hot stage is used to study the cell nucleation, growth, coalescence and coarsening in LLDPE melts, providing an improved understanding of the foaming dynamics with a chemical blowing agent in rotational moulding. Finally, the actual foaming behaviour in rotomoulding is studied. The experimental results indicate that the amount of blowing agent, the heating time and the processing temperature play an important role in determining the cell morphology in rotational foam moulding. 27 refs.

Accession no.687558 Item 224 Antec 98. Volume II. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.1842-9. 012 PRODUCT AND PROCESS DEVELOPMENTS IN THE NITROGEN AUTOCLAVE PROCESS FOR POLYOLEFIN FOAM MANUFACTURE Eaves D E; Witten N Zotefoams plc (SPE) A review is presented of the nitrogen autoclave process for the manufacture of crosslinked polyolefin foams. Process and product developments over the last few years are summarised and future possibilities are described. Process developments include use of higher temperatures and pressures to produce foams having densities as low as 10 kg/cub.m. Product developments include foams based on HDPE/LDPE blends, propylene copolymers and metallocene-catalysed ethylene copolymers. The structure and properties of these foams are compared with those of foams produced by alternative processes. 5 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.687548 Item 225 Antec 98. Volume II. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.1832-6. 012 STRUCTURE/PROCESS/PROPERTY RELATIONSHIPS IN MOULDED POLYETHYLENE FOAMS Sims G L A; Mahapatro A UMIST (SPE) Structure, process and property relationships of moulded PE foams are investigated. Two compression moulding variations are used, namely single stage and heat and chill processes. Using either process, crosslinking and chemical blowing agent decomposition occur under identical conditions followed by expansion at different temperatures. Foam densities are correlated to degree of crosslinking and tensile stress-strain curves of unfoamed crosslinked polymer (of the same gel content) determined at temperatures corresponding to those of foam expansion. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.687546

© Copyright 2004 Rapra Technology Limited

CANADA

Accession no.687545 Item 227 Antec 98. Volume I. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.1161-5. 012 EXPERIMENTAL STUDY OF FOAMED POLYETHYLENE IN ROTATIONAL MOULDING Liu S-J; Tsai C-H Chang Gung,University (SPE) Rotational moulding of PE foams has increasingly become an important process in industry because of their thicker walls, lower sound transfer, higher stiffness and good thermal insulation. However, the foaming process of PE in rotational moulding has not been well studied. The rotomouldability of foamed PE and moulded product properties are examined. Characterisation of powder and moulded part properties is performed. In addition, the role of blowing agent on the process is discussed. 16 refs. TAIWAN

Accession no.684694 Item 228 Foamplas 97. Conference proceedings. Mainz, Germany, 4th-5th Nov.1997, p.277-89. 6124 NEW MODIFIED AZODICARBONIC ACID DIAMIDE FOR CROSSLINKED POLYOLEFIN FOAMS

75

References and Abstracts

Facklam T Bayer AG (Schotland Business Research Inc.) Crosslinked PE foam is widely used today in the automotive, sport, leisure and packaging industries. The role of azodicarbonic acid diamide (ADC) in its manufacture is illustrated, showing possibilities of improving the production quality of chemically crosslinked PE foams by adding a modified azodicarbonic acid diamide. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.683837 Item 229 Foamplas 97. Conference proceedings. Mainz, Germany, 4th-5th Nov.1997, p.181-208. 6124 PROCESSING INNOVATIONS FOR NEW POLYMERS IN THE PHYSICAL FOAMING PROCESS Reimker M Berstorff H.,Maschinenbau GmbH (Schotland Business Research Inc.) The extruder-based physical foaming process and special requirements for new polymer foams made of PP, thermoplastic elastomers and PETP are described. Because of some different physical properties of these polymers, the blowing agents and the product characteristics, the machinery and equipment as well as the recipe and process parameters need to be adapted accordingly. The right selection of machine and line components is essential for an economical and troublefree operation of a production line. For the physical foaming process, the most important engineering details are extruder design, barrel length, screw design, heating/ cooling system, blowing agent injection system, foam extrusion head, calibrating and other downstream equipment. Applications for new polymer foams can be found in the automotive industry, for special packaging, transportation and insulation purposes as well as many other technical articles. 18 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.683831

20 million tons and overall growth rates are still close to 10%, higher than for most traditional polymers. At the origin of this success is the remarkable combination of properties offered by PP and the ability to modify these properties within a broad spectrum. Tailored mechanical properties, high service temperature, inertness in contact with food, resistance to a broad range of chemicals and ease of recycling are just a few of PP’s assets, making it the polymer of choice for many applications in the automotive and packaging industries. Through major advances in both catalyst and reactor technology, Montell has been instrumental in expanding the performance envelope of PP. Several trends in today’s industry and society favour the combination of PP properties and the advantages offered by foam structures. The use of PP foam in automotive and packaging applications, with some emphasis on recyclability or waste reduction is discussed. 2 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN EUROPE

Accession no.683829 Item 231 Foamplas 97. Conference proceedings. Mainz, Germany, 4th-5th Nov.1997, p.87-115. 6124 NEW POLYETHYLENE AND POLYSTYRENE POLYMERS FOR FOAM APPLICATIONS Kelusky E C Nova Chemicals Ltd. (Schotland Business Research Inc.) Polyolefin foams are a growing application, buoyed in part by the development of new polyolefins with properties suitable for foam applications. Historically, polyolefins have been used because they are flexible and tough and show good resistance to abrasion and chemicals. The advent of new families of polyolefins based on new reactor, catalyst and copolymer technologies have expanded the opportunities for polyolefins in foams. Nova Chemicals has developed a wide range of products for foam applications and is developing new technology for these applications. The products include Arcel, a mouldable PE/PS interpolymer; Dylite, an expandable PS; Novapol LDPE, for foamed PE; and Advanced Sclairtech, a new PE technology which is currently being commercialised. Details are given. CANADA

Item 230 Foamplas 97. Conference proceedings. Mainz, Germany, 4th-5th Nov.1997, p.149-62. 6124 HIGH MELT STRENGTH PP FOAMS FOR THE AUTOMOTIVE AND PACKAGING INDUSTRIES Van Calster M Montell Polyolefins Co. (Schotland Business Research Inc.) Since Ziegler and Natta’s discovery of a catalyst system to produce PP, this polymer has enjoyed formidable growth. Today, the world market for PP is estimated at

76

Accession no.683826 Item 232 Foamplas 97. Conference proceedings. Mainz, Germany, 4th-5th Nov.1997, p.65-85. 6124 LABORATORY EVALUATION OF METALLOCENE RESINS IN CROSSLINKED POLYETHYLENE (XLPE) FOAM Heck R L Uniroyal Chemical Co.Inc. (Schotland Business Research Inc.)

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Using a laboratory technique previously developed to evaluate the performance of chemical foaming agents in XLPE foam, metallocene polyolefins are evaluated at various addition levels to branched LDPE to determine their effect on general foam quality (cell size, density, appearance). The laboratory method is discussed, and conclusions on acceptable levels of the metallocene resins are offered. 5 refs. USA

Accession no.683825 Item 233 Blowing Agent Systems: Formulations and Processing. Seminar proceedings. Shawbury, 19th Feb.1998, paper 6. 57 GAS SOLUBILITY: A KEY FEATURE OF CURRENT ECONOMIC AND ENVIRONMENTAL QUESTIONS FOR EXTRUDERS OF THERMOPLASTIC FOAMS Gale M Rapra Technology Ltd. (Rapra Technology Ltd.) High density foams generally use conventional extrusion lines, and the blowing agents are specially formulated chemicals which decompose at the elevated temperatures of molten polymers to liberate the necessary gas. Low density foams, typically packaging and insulation products, are foamed on special equipment using direct injection of a physical blowing agent which does not undergo any reaction. The most commonly used chemical blowing agents (CBAs) liberate either carbon dioxide or nitrogen plus miscellaneous gaseous and solid chemicals. Physical blowing agents are usually either hydrocarbons such as pentane or HCFCs. Carbon dioxide and nitrogen liberated from chemical blowing agents cost about ten times that used from cylinders. There are also problems of variable amounts of gas evolved causing extrusion problems as well as potential fire and respiratory problems with some CBAs. The results of Rapra extrusion trials using nitrogen, argon and carbon dioxide are presented. 14 refs.

(azodicarbonamide) within an EVA carrier resin to form a pelletised compound, which is combined with HDPE and extruded. The melt temperature of the pelletised blowing agent is lower than that of the PE and controls the expansion of the polyethylene. USA

Accession no.680439 Item 235 Patent Number: US 5698144 A 19971216 PROCESS FOR PRODUCING LOW DENSITY POLYETHYLENIC FOAM WITH ATMOSPHERIC GASES AND POLYGLYCOLS OR POLYGLYCOL ETHERS Wilkes G R; Dunbar H A; Bly K A; Uhl E R Tenneco Protective Packaging Inc. Polyglycols and polyglycol ethers exhibiting gas absorption properties and plasticising effects in polyethylenic extrudates are combined with physical atmospheric blowing agents, such as nitrogen, argon, carbon dioxide, water and blends thereof, to produce uncrosslinked polyethylenic foams having densities as low as 10 kg/cu.cm. USA

Accession no.680333 Item 236 Advances in Polymer Technology 17, No.2, Summer 1998, p.87-106 GAS DIFFUSION IN DENSE PE FOAMS Briscoe B J; Savvas T Imperial College An experimental and theoretical study of the degassing of an LDPE high-density foam is presented. Measurements of the mass, dimensions, and density as a function of storage time are reported. A geometrical model is described to represent the basic mass transport and volume relaxation processes in a cellular system. Model predictions were compared with experimental results. 12 refs.

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.683412

Accession no.679379

Item 234 Patent Number: US 5698604 A 19971216 DURABLE CASE FORMED FROM AN EXPANDED HIGH-DENSITY POLYETHYLENE Kiley D L American Trading & Production Corp.

Item 237 New Plastics 98. Conference proceedings. London, 21st-22nd Jan.1998, paper 19. 6 EMERGING APPLICATIONS AND PERFORMANCE ATTRIBUTES OF ULTRA LOW DENSITY METALLOCENE FOAMS Smith S C Sentinel Products Corp. (European Plastics News)

A case, such as an attache case or briefcase, has a cover panel, back panel, front panel, top panel, bottom panel opposing tabs and opposing side panels. It is made from a unitary sheet of expanded PE, which is produced by encapsulating a thermoplastic blowing agent

© Copyright 2004 Rapra Technology Limited

For 30 years, conventional foams have been described as rubber or plastic. With the advent of metallocene foams,

77

References and Abstracts

there is no longer a relevant distinction between rubber and/or plastic foams. The only difference between what is commonly referred to as a rubber or plastic foam is the stiffness or flexibility of the resultant foam. The emerging applications and performance benefits of a technology that has created new breeds of metallocene foams referred to as ULMEs (Ultra Low Density Metallocene Elastomers) and ULMPs (Ultra Low Density Metallocene Plastomers) are described. USA

Accession no.679273 Item 238 Journal of Applied Polymer Science 68, No.8, 23rd May 1998, p.1237-44 EFFECT OF ADDITION OF EVA ON THE TECHNICAL PROPERTIES OF EXTRUDED FOAM PROFILES OF LOW-DENSITY POLYETHYLENE/EVA BLENDS Rodriguez-Perez M A; Duijsens A; de Saja J A Valladolid,Universidad; Sekisui Alveo BV The static and dynamic mechanical properties, creep recovery behaviour, thermal expansion and thermal conductivity of low-density foams made of blends of LDPE and EVA were studied as a function of the EVA content of the blends. These properties were compared with those of a foam made from a blend of EVA and ethylene-propylene rubber. A knowledge of the way in which the EVA content affects the behaviour of these blend foam materials is fundamental to obtaining a wide range of polyolefin foams, with similar density, suitable for different applications. 9 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; SPAIN; WESTERN EUROPE

Accession no.679109 Item 239 Patent Number: EP 839857 A2 19980506 POLYMERIC FOAM WITH ANTIBACTERIAL AND MILDEWPROOFING FUNCTIONS Mori S This comprises a copolymer containing 72 to 95 wt.% of ethylene and 28 to 5 wt.% of vinyl acetate and a small amount of organic composite having a bactericidal action contained therein, which is composed mainly of N,Nd i m e t h y l - N ’ - p h e n y l - N ’ (fluorodichloromethylthio)sulphamide, 1,2benzisothiazoline-3-on, diiodomethyl-p-tolylsulphone and methyl(benzimidazol-2-yl)carbamate. It is suitable as cushioning material for floors and walls and as a material for building blocks and babies’ toys. JAPAN

Accession no.678704

78

Item 240 Industrial & Engineering Chemistry Research 37, No.4, April 1998, p.1464-72 MODEL FOR FOAM DEVOLATILISATION IN AN EXTRUDER Yang C-T; Smith T G; Bigio D I; Anolick C Maryland,University; DuPont de Nemours E.I.,& Co.Inc. Details are given of the development of a model for the design of the devolatilisation section in an extruder which was optimised with respect to foam growth and process parameters. A statistical regression method and a backpropagation neural network were used to develop correlations. A case study for model demonstration is given using PE/acrylic acid devolatilisation in a corotating twin-screw extruder. 41 refs. USA

Accession no.678613 Item 241 Cellular Polymers 17, No.1, 1998, p.31-6 LABORATORY EVALUATION OF METALLOCENE RESINS IN CROSSLINKED POLYETHYLENE FOAM Heck R L Uniroyal Chemical Co.Inc. Using a laboratory technique previously developed to evaluate the performance of chemical foaming agents in crosslinked PE foam, metallocene polyolefins were evaluated at various levels of addition to branched LDPE to determine their effect on general foam quality, e.g. cell size, density and appearance. The laboratory method is discussed and conclusions on acceptable levels of the metallocene resins are presented. 5 refs. (Foamplas ’97, Mainz, Germany, Nov.1997) USA

Accession no.677566 Item 242 Varmdo, 1998, pp.6. 30cms. 15/4/98 English; German; French POLYPROPYLENE - THE FOAMS OF THE FUTURE Fagerdala World Foams AB A trilingual brochure gives details of the polypropylene foam product range of Fagerdala World Foams. The materials offer modifiable product characteristics to suit various needs, high temperature resistance, and complete recyclability. Products include Fawolit extruded rolls and sheets for industrial and packaging applications and Fawocel semi-flexible moulded parts, blocks and sheets with high energy absorption. The Fawotop range of moulded and thermoformed parts features a sandwich construction of extruded PP rolls or sheets and PP particle

© Copyright 2004 Rapra Technology Limited

References and Abstracts

foam with improved toughness at low density. Brief coverage is also given to the company’s range of polyethylene foams. SCANDINAVIA; SWEDEN; WESTERN EUROPE

Accession no.676621 Item 243 Kobunshi Ronbunshu 55, No.2, 1998, p.74-82 Japanese DYNAMIC COMPRESSION MODULUS OF ELASTICITY IN OPEN-CELLED POLYETHYLENE FOAMS Adachi H; Hasegawa T; Kotani N Nagoya Municipal Industrial Research Institute; Sanwa Kako Corp. The dynamic compression modulus values of elasticity in some open-celled polyethylene foams were established by measuring frequency and temperature characteristics of viscoelasticity in compression mode. The dynamic compression modulus values of elasticity were found to be useful to evaluate compression characteristics of the foam, as were other dynamic properties. 14 refs. JAPAN

Accession no.676307 Item 244 Modern Plastics International 28, No.3, March 1998, p.92 PP FOAM It is briefly reported that PP foam sheet from Convenience Food Systems in thickness from 500 to 1800 micron is thermoformable into chilled food packaging trays. Trays made in TiroPak XPP, which is coextruded with an EVOH barrier layer, can be taken from the freezer and heated to 90C in a microwave oven without loss of shape or properties. CONVENIENCE FOOD SYSTEMS BV EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

of radiating fibrils. Pore radii covering the mesopore range (2-50nm), making their largest contribution at 10-20 nm, were calculated from nitrogen adsorption isotherms. Surface areas of the correct order of magnitude were obtained by assuming that gas adsorption took place on the surfaces of lamellar crystals. Crystallisation of isotactic PP from n-butane and n-heptane generated foams of lower mesoporosity and smaller surface area. These more ‘liquid-like’ solvents did not allow for formation of an open network of mesopores or they promoted its collapse upon their removal. 22 refs. USA

Accession no.672015 Item 246 Plast 21 No.55, Oct.1996, p.117-20 Spanish THERMOPLASTIC POLYESTER FOAMS FOR THE MANUFACTURE OF SANDWICH PANELS Madariaga L; Gomez J L; Mediavilla A Gaiker Results are presented of experiments undertaken by Gaiker in the manufacture of sandwich panels containing foam cores based on PETP recycled by a solid state polyaddition process developed by M & G Ricerche. Panels were produced with glass fibre-reinforced unsaturated polyester and epoxy resin skins, and allthermoplastic panels with PE, PP, PS and glass fibrereinforced PETP skins were also produced. EVA hot melt adhesives and thermoset adhesives were evaluated in bonding glass fibre-reinforced PETP skins to the foam cores. Data are presented for the mechanical properties of the structures studied. M & G RICERCHE SPA; BERSTORFF H.,MASCHINENFABRIK GMBH; SISTEMA COMPOSITI SPA; NAPLES,UNIVERSITY; INSTITUT FUER CHEMIEFASERN EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; ITALY; SPAIN; WESTERN EUROPE

Accession no.670869

Accession no.673014 Item 245 Journal of Polymer Science : Polymer Physics Edition 36, No.4, March 1998, p.617-27 ISOTACTIC POLYPROPYLENE FOAMS CRYSTALLIZED FROM COMPRESSED PROPANE SOLUTIONS Whaley P D; Kulkarni S; Ehrlich P; Stein R S; Winter H H; Conner W C; Beaucage G Massachusetts,University; Cincinnati,University Crystallisation of isotactic PP from homogeneous solution in supercritical propane yielded open-cell foams of high surface area. Their morphology usually consisted of microspheres with a dense core and a porous periphery

© Copyright 2004 Rapra Technology Limited

Item 247 Patent Number: EP 823443 A2 19980211 FOAMED PARTICLES OF MODIFIED POLYPROPYLENE RESIN AND METHOD OF PREPARING SAME Sasaki H; Sakaguchi M; Tokoro H JSP Corp. The foamed, non-crosslinked resin particles, which have a bulk density of not greater than 0.045 g/cu.cm. and an average cell diameter of at least 200 pm, include PP to which a vinyl comonomer is graft polymerised in such an amount that the weight ratio of the PP to the graft polymer of the vinyl comonomer is in the range of 97:3 to 65:35. They are produced by graft polymerisation at a

79

References and Abstracts

temperature of less than 90C in the presence of a specific radical polymerisation initiator, which requires a temperature of not higher than 70C to obtain a half life of 10 hours, to produce modified PP resin particles and then expanding the particles. JAPAN

Accession no.667930 Item 248 Revue Generale des Caoutchoucs et Plastiques No.749, April 1996, p.38-9 French FOAMABLE INSERTS FOR SOUNDPROOFING CARS Rimkus R Ymos A method developed by Ymos of Belgium for the soundproofing and stiffening of vehicle shells based on a process patented by Exxon is described. Preformed foamable ethylene copolymer inserts formulated with azodicarbonamide and sulphonhydrazide blowing agents and peroxide curing agents are placed in cavities in the bodywork on the assembly line, and foaming takes place during passage through an oven at a temperature between 140 and 180C. Developments in this technology between 1991 and 1995 are reviewed. EXXON CHEMICAL CO. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; USA; WESTERN EUROPE

Accession no.663524 Item 249 Macplas International No.14, Nov. 1997, p.56 EXTRUSION ROUTE FOR POLYPROPYLENE FOAMS A review is presented of developments in the production of polypropylene foam with particular reference to long chain branching technology. This technology provides PP foams with exceptional melt strength and strain hardening, it is claimed, and allows for the commercial viable production of PP foams by simple processes such as extrusion. Advantages of foam extrusion are discussed, together with details of applications, including automotive and packaging. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.662728 Item 250 Patent Number: US 5601766 A 19970211 METHOD OF MAKING A SUN VISOR FOR MOTOR VEHICLES Viertel L; Welter P Happich GmbH

80

A sun visor has a generally board shaped body of dark coloured PP particle foam with a depression in a main surface thereof. A shaped light coloured body is inserted into the depression and is pressed against the bottom of the depression through simultaneous application of heat and pressure, for compacting and reshaping the shaped body to form a reflector. A mirror assembly is disposed over the reflector, and an illuminating device may be disposed there. Fastening pins and openings on the reflector in the mirror assembly and the illuminating device hold them together. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.660664 Item 251 Patent Number: US 5554661 A 19960910 CLOSED CELL, LOW DENSITY ETHYLENIC POLYMER FOAM PRODUCED WITH INORGANIC HALOGEN-FREE BLOWING AGENTS Chaudhary B I; Eschenlauer G; Marks B S Dow Deutschland Inc. An uncrosslinked, closed cell, low density ethylenic polymer foam having a density of less than 150 kg/cu.m is prepared from, for example, uncrosslinked low density polyethylene using inorganic blowing agents, such as carbon dioxide, argon, or mixtures thereof. A process for preparing such uncrosslinked, closed cell, low density ethylenic polymer foam comprising extruding an ethylenic polymer of suitable melt tension using a 100% inorganic blowing agent, and the foams produced with this process, are also disclosed. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.657966 Item 252 Patent Number: US 5616627 A 19970401 POLYPROPYLENE RESIN COMPOSITION, POLYPROPYLENE RESIN FOAMED MATERIAL AND PROCESS FOR PRODUCING THE SAME Sakurai T; Asao K; Sakamoto A Sumitomo Chemical Co.Ltd. This composition contains about 90 to 60 pbw of a PP block copolymer and about 10 to 40 pbw of a PE. The block copolymer contains about 99 to 90 wt.% of a crystalline PP and about 1 to 10 wt.% of an amorphous ethylene/alpha-olefin copolymer and has a melt flow rate of about 2 to 15 g/10 min and a die swell ratio, measured by a capillary rheometer, of at least 1.7. Foamed materials containing a fine and uniform foam are obtained from this composition. JAPAN

Accession no.657337

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 253 Cellular Polymers 16, No.4, 1997, p.271-83 AZOCARBONAMIDE AND SODIUM BICARBONATE BLENDS AS BLOWING AGENTS FOR CROSSLINKED PE FOAMS Sims G L A; Sirithongtaworn W UMIST Thermal decomposition characteristics of chemical blowing agents based on azodicarbonamide and sodium bicarbonate were investigated. Their use in crosslinked PE foam formulations are discussed. Density and inmould temperature profiles were interpreted in the light of blowing agent system properties, detailed process parameters and permeability of individual gaseous decomposition products through PE. 11 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

of extruded products are encountered. The dimensional stability of a foam with a structure of closed cells is improved by blending the polymer with small amounts of a low molecular weight additive. It is believed that the dimensional stability is related to the ratio of the blowing agent to air permeability. It is shown that the additive reduces the blowing agent permeability more than it does the air permeability only if the additive has migrated to the surface of the polymer. The presence of the additive at the polymer surface is confirmed by electron microscopy and IR spectroscopy. The (partially) ordering of the additive at the surface, as shown with wide-angle X-ray diffraction, explains the low gas permeabilities of the additive compared to the corresponding permeabilities of PE. 11 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.653182

Accession no.655740 Item 254 Cellular Polymers 16, No.3, 1997, p.194-215 TIME DEPENDENCE OF THE COMPRESSIVE RESPONSE OF POLYPROPYLENE BEAD FOAM Mills N J Birmingham,University PP bead foams of a range of densities were compressed using impact and creep loading in an Instron test machine. The stress-strain curves were analysed to determine the effective cell gas pressure as a function of time under load. Creep was controlled by the polymer linear viscoelastic response if the applied stress was low but, at stresses above the foam yield stress, the creep was more rapid until compressed cell gas took the majority of the load. Air was lost from the cells by diffusion through the cell faces, this creep mechanism being more rapid than in extruded foams, because of the small bead size and the open channels at the bead boundaries. The foam permeability to air could be related to the PP permeability and the foam density. 15 refs.

Item 256 Patent Number: US 5567742 A 19961022 DIMENSIONALLY-STABLE POLYPROPYLENE FOAM EXPANDED WITH INORGANIC BLOWING AGENTS Park C P Dow Chemical Co. A low density, dimensionally-stable, extruded propylene polymer foam comprises an expanded propylene polymer material where the foam has a blowing agent comprising at least 15 wt % of one or more inorganic blowing agents. The propylene polymer material comprises at least 15 wt %. of propylene monomeric units. The foam has a density of 10-150 kg per cubic metre. The foam has an average cell wall thickness of less than 35 micrometres. USA

Accession no.652233

Accession no.654866

Item 257 Patent Number: US 5605936 A 19970225 FOAMED ARTICLES COMPRISING HIGH MELT STRENGTH PROPYLENE POLYMER MATERIAL DeNicola A J; Smith J A; Felloni M Montell North America Inc.

Item 255 Journal of Applied Polymer Science 65, No.13, 26th Sept.1997, p.2679-89 FOAM STABILITY RELATED TO POLYMER PERMEABILITY. I. LOW MOLECULAR WEIGHT ADDITIVES Bouma R H B; Nauta W J; Arnauts J E F; Van Den Boomgaard T; Steuten J M; Strathmann H Twente,University; DSM Research

The above polymer is produced by high energy radiation of a normally solid, high molec.wt., linear propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such an environment for a specific period of time and then deactivating free radicals in the material. It has high melt strength due to strain hardening, which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer and is used in extensional flow operations, e.g. extrusion coating, film production, foaming and thermoforming.

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

In the production of PE foams by extrusion with alkanes as a blowing agent, significant changes in the dimensions

© Copyright 2004 Rapra Technology Limited

USA

Accession no.651216

81

References and Abstracts

Item 258 Journal of Cellular Plastics 3, No.4, July/Aug.1997, p.304-17 STUDY OF REACTION KINETICS INVOLVED IN CROSSLINKED LDPE FOAM Tai H-J; Wang J B KaoHsiung,Polytechnic Institute The reaction kinetics of crosslinked LDPE foam systems is investigated. Dicumyl peroxide (DCP) is used as the crosslinker. The crosslinking reaction of LDPE/DCP system is controlled by a first order decomposition of DCP. The reaction kinetics of a chemical blowing agent, azodicarbon amide (ADCA), and its kicker, zinc oxide (ZnO), is also investigated. The rate of reaction of ADCA is very fast, and a general nth-order reaction kinetics fails to predict its conversion. A model combining a general nth-order reaction kinetics and autocatalytic reaction kinetics is adopted instead. The addition of ZnO into ADCA not only lowers the decomposition temperature, but also accelerates its decomposition. The reaction kinetics of the LDPE/ADCA/ZnO system is also studied, and is found to be similar to those of ADCA/ZnO system. The numerical results serve as a framework for future prediction and simulation of molecular structure changes of a reactive polymeric foam system. 16 refs. TAIWAN

Accession no.650853 Item 259 Polymer Engineering and Science 37, No.6, June 1997, p.959-65 DYNAMIC MECHANICAL PROPERTIES OF POLYOLEFIN FOAMS STUDIED BY DMA TECHNIQUES Rodriguez-Perez M A; Rodrigues-Llorente S; De Saja J A Valladolid,Universidad A preliminary study on the viscoelastic behaviour of polyolefin foam sheets with different chemical (PE and PP) and cellular structure by DMA, in the low frequency and low compression ranges, is presented. DSC and SEM are also used to determine the morphological parameters of the samples. A connection between the morphological properties (apparent degree of crystallinity), type of cellular structure, homogeneity, cell size and shape, cell wall thickness) and the viscoelastic behaviour, a basic key for the development of mechanical and insulating applications, has been established. 9 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.650250 Item 260 Modern Plastics International 27, No. 9, Sept. 1997, p.112/7 PP FOAM SHEET EMERGES AS A CONTENDER FOR A RANGE OF APPLICATIONS

82

Mapleston P The advantages offered by PP foamed sheet are discussed, with particular reference to its balance of strength and light weight, and its potential applications in markets ranging from car panels to cups. The fast developing market sector is shown to be drawing materials suppliers to develop high melt flow grades and equipment suppliers to focus on extrusion lines for PP foam. These developments from specific manufacturers and suppliers are reviewed. EUROPE-GENERAL; USA

Accession no.649430 Item 261 Croydon, 1996, pp.2. 30cms. 25/6/97 EVAZOTE ETHYLENE VINYL ACETATE CONDUCTIVE FOAM 45 KG/M3, 80 KG/M3, 120 KG/M3 Zotefoams plc This data sheet presents property details for three grades of Evazote, a closed-cell, cross-linked EVA copolymer foam available in sheet form. The grades - EV45CN, EV70CN, and EVC120CN - are of varying densities and are suitable for the protection of static sensitive devices and assemblies, shorting out IC leads and cushion packaging. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.647076 Item 262 Polyurethanes Expo 96. Conference Proceedings. Las Vegas, Nv., 20th-23rd Oct.1996, p.179-89. 43C6 LOW DENSITY ALL WATER-BLOWN RIGID FOAM FOR POUR-IN-PLACE APPLICATIONS Kaplan W A; Neill P L; Staudte L C; Brink C J Stepan Co. (SPI,Polyurethane Div.) The dimensional stability of low density, water blown rigid PU foams for pour-in-place thermal insulation applications was improved by the use of a phthalic anhydride based polyester polyol containing a dispersed cell opening agent. The foam systems obtained allowed some of the carbon dioxide to be released through the cell windows immediately after filling of the cavity, and to be rapidly replaced by air. Studies were made of the flowability, density, open cell content, dimensional stability, mechanical properties, thermal conductivity and adhesion (particularly to flame treated PE) of these foams. These properties were examined in comparison with those of HCFC-141b blown foams. 21 refs. USA

Accession no.643053

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 263 British Plastics and Rubber July/Aug.1997, p.24 BLOW MOULDED FOAM TECHNOLOGY GOES INTO PRODUCTION FOR PALLETS Krupp Kautex’ BFT, blowmoulding foam technology, has reached commercial fruition and its first industrial-scale application will be at a new company, BFT Plastics in Northern Ireland, where a machine to mould pallets and transport boxes will be installed later this year. The BFT process uses a chemical blowing agent to foam HDPE to increase rigidity and impact resistance and improve heat insulation. BFT PLASTICS EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.642816 Item 264 Patent Number: US 5576080 A 19961119 POLYETHYLENIC FOAMING COMPOSITIONS AND MOULDED FOAMS Sugimoto H; Igarashi T; Nakatsuji Y; Tatsumi M; Chikanari K; Funakoshi S Sumitomo Chemical Co.Ltd. This invention provides a polyethylenic foaming composition comprising (a) 100 pbw of an ethylenic copolymer having glycidyl groups consisting of 20-99.9% by weight of ethylene units, 0.1-30% by weight of a unit of a glycidyl ester of an unsaturated carboxylic acid or an unsaturated glycidyl ether, and 0-50% by weight of ethylenically unsaturated ester units other than a glycidyl ester, (b) 0.1-30 pbw of a carboxylic acid having 2 or more carboxyl groups and a molecular weight of 1500 or less, and (c) 0.1-20 pbw of a foaming agent of a thermal decomposition type. The invention also provides a polyethylenic foam moulded from the foaming composition. In addition, the invention provides a moulded composite foam having a foam layer moulded from a powder of the foaming composition and a nonfoam layer moulded from a composition powder containing a certain thermoplastic elastomer, as well as a multilayer moulded article containing the moulded composite foam. A foam having excellent lightness in weight, excellent cleanness, uniformly foamed cells, high expansion ratio, and excellent impact resilience can be obtained. JAPAN

Accession no.640891 Item 265 Patent Number: US 5580503 A 19961203 CONTINUOUS PROCESS FOR EXPANDING THERMOPLASTIC MINIPELLETS Hall T N; Trivedi Y C BASF Corp.

© Copyright 2004 Rapra Technology Limited

Minipellets, particularly PP minipellets, are continuously expanded by continuously charging and mixing water and minipellets in a slurry tank to form a slurry, which is subsequently pressurised. A blowing agent, such as butane, is entrained into the pressurised slurry flow and the slurry is heated by a heating means, such as a shell and tube heat exchanger, to the softening point of the minipellets. The heated minipellets are given the time necessary for impregnation by permitting them to flow through one or more impregnation vessels. The impregnated minipellets are released through an orifice into an expansion vessel where the blowing agent flashes off, thereby expanding the minipellets. USA

Accession no.640634 Item 266 Journal of Cellular Plastics 33, No.3, May/June 1997, p.264-92 CREEP AND RECOVERY OF POLYOLEFIN FOAMS - DEFORMATION MECHANISMS Mills N J; Gilcrist A Birmingham,University The effects of gas compression and Poisson’s ratio on the compressive stress-strain curves of closed cell foams were analysed. The contributions of hardening, polymer viscoelasticity and gas escape on creep were examined. The foam diffusivity for air was predicted from the polymer permeability and the foam density. Diffusivity values, derived from fitting creep curves of LDPE and EVA foams, were of the correct order of magnitude. Creep was dominated by the polymer viscoelasticity if the stress was less than the yield stress, but at higher stresses gas compression took an increasing proportion of the load. Gas escape was a creep mechanism operating on a timescale that depended on the size of the foam block. The consequences of the high gas diffusivity for the creep design for polyolefin foams are discussed. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.638782 Item 267 Antec 97. Volume II. Conference proceedings. Toronto, 27th April-2nd May 1997, p.2060-4. 012 MICROCELLULAR CROSSLINKED EVA FOAM BY INJECTION MOULDING PROCESS Lee J J AT Plastics Inc. (SPE) The injection moulding process for producing a microcellular crosslinked EVA has several advantages over the conventional compression moulding process: reduced cycle time, labour and scrap. The presence of skin adds aesthetic value and ability to engrave logos in one step. However, the injection moulding process has

83

References and Abstracts

not been widely accepted particularly in such applications as shoe soles, where precise size control is of utmost importance. This has been due to lack of precision compounds as well as high quality injection moulding machines. Recent progress in injection moulding and compounding technology has made it possible to replace the compression moulding process in producing foams for the most demanding applications. The injection moulding process, moulding compounds and resultant foam properties are reviewed. USA

Accession no.638341 Item 268 Antec 97. Volume II. Conference proceedings. Toronto, 27th April-2nd May 1997, p.2000-4. 012 CHARACTERISATION OF CROSSLINKED POLYETHYLENE FOR FOAM EXPANSION USING BUBBLE MACHINE Park C P Dow Deutschland Inc. (SPE) A simple bubble machine is devised and successfully applied in characterising lightly crosslinked PE resins for foam expansion. The biaxial stress-strain relationship is deduced from the air injection rate and pressure. The effects of strain rate, temperature and crosslinker level on the stress-strain behaviour are investigated. Uniaxial extension experiments are also performed and compared with biaxial extension data. 5 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.638329 Item 269 Polymer Plastics Technology and Engineering 36, No.2, 1997, p.257-71 STRUCTURE OF PP STRUCTURAL FOAM MOULDINGS MADE BY THE GAS-COUNTERPRESSURE PROCESS Djoumaliisky S; Touleshkov N; Kotzev G Bulgarian Academy of Sciences An experimental study was carried out to investigate the gas counter-pressure process by egress of a part of the polymer melt from the core of the moulded body towards the accumulator. A systematic study of bubble morphology development and structural parameters of structural foam mouldings was conducted. The structural foam samples were produced on a two-stage moulding machine with passively-transporting accumulator and on an in-line injection moulding machine with FIFO-type accumulator, the melt temp. being varied in the range 473 to 533K. The polymer used was isotactic PP into which chemical blowing agent (azodicarbonamide) was added. The structural properties studied were overall density, local density and density distribution. It was found that

84

the distance from the sprue to the extreme of flow and the melt temp. had a significant effect on the bubble sizes and their distribution. It was established that the use of the two types of accumulator caused significant differences in the structural organisation of the structural foam mouldings. 8 refs. BULGARIA; EASTERN EUROPE

Accession no.632816 Item 270 Cellular Polymers 16, No.2, 1997, p.87-109 EFFECTS OF HEAT TRANSFER AND POISSON’S RATIO ON THE COMPRESSIVE RESPONSE OF CLOSED-CELL POLYMER FOAMS Mills N J; Gilchrist A Birmingham,University Gas compression in closed-cell polymer foams was analysed, and the effect on the uniaxial compression stress-strain curve predicted. Results were compared with experimental data for ‘a’ foams with a range of cell sizes, and the heat transfer conditions inferred from the best fit with the simulations. The lateral expansion of the foam must be considered in the simulation, so in subsidiary experiments Poisson’s ratio was measured at high compressive strains. 13 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.632133 Item 271 International Polymer Science and Technology 23, No.11, 1996, p.T/100-6 SELECTED PROPERTIES OF CELLULAR POLYETHYLENE Sikora S L A study was made of the effects of processing conditions and of blowing and nucleating agents and external lubricants on the apparent density, mechanical properties, linear thermal expansion coefficient and surface roughness of extruded cellular MDPE. Based on the results, recommendations were formulated for the properties of cellular MDPE pipes for the protection of light conducting cables. 16 refs. (Translation of Polimery, Tworzywa Wielkoczasteczkowe, No.10, 1996, p.580). EASTERN EUROPE; POLAND

Accession no.629936 Item 272 Journal of Thermal Insulation 20, Jan.1997, p.206-26 BARRIER EIFS CLAD WALLS: RESULTS FROM A MOISTURE ENGINEERING STUDY Brown W; Ullett J; Karagiozis A; Tonyan T Canada,National Research Council; USG Research Center

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Details are given of water penetration and moisture characteristics of barrier Exterior Insulation Finish Systems clad walls. The study includes results from a field investigation, laboratory experiments and computer simulations. The system includes a PE vapour retarder and PS foam. 2 refs. CANADA; USA

Accession no.629796 Item 273 Polymer Engineering and Science 37, No.1, Jan.1997, p.1-10 STUDY OF CELL NUCLEATION IN THE EXTRUSION OF POLYPROPYLENE FOAMS Park C B; Cheung L K Toronto,University Cell nucleation and initial cell growth were studied in the extrusion of foams based on linear and branched PP using carbon dioxide and isopentane as blowing agents. The cell density generally increased with increased blowing agent content. The effect of processing pressure on cell density was distinct when carbon dioxide was used, whereas no pressure effect was observed with isopentane. The cell morphologies for the two types of PP were significantly different. A slightly lower density of nuclei was observed in branched PP foams than in linear PP foams, but cell coalescence was observed much less in branched PP foams. Most cells in the branched PP foams were closed, while in the linear PP foams they were connected to each other. Experimental results indicated that the branched structure played an important role in determining cell morphology through its effects on melt strength and/or melt elasticity. 40 refs. CANADA

Toronto,University An investigation of the cell nucleation of polypropylene foams in extrusion was conducted. A linear grade of PP was processed with hydrocerol as a nucleating agent and isopentane as a blowing agent. Blends of PP with various hydrocerol contents (0.1%, 0.5%, 1% and 2% by weight) were prepared. The isopentane contents were approximately 1%, 3% and 6% by weight. The effects of the isopentane and hydrocerol content and the pressure on the cell-population density were investigated. Results and possible nucleation mechanisms are discussed. 29 refs. CANADA

Accession no.625218 Item 276 Journal of Vinyl and Additive Technology 2, No.4, Dec.1996, p.339-344 USE OF INERT GASES IN EXTRUDED MEDIUM DENSITY POLYPROPYLENE FOAMS Dey S K; Natarajan P; Xanthos M; Braathen M D Hoboken,Polymer Processing Institute; Borealis SA Carbon dioxide gas was used as a physical blowing agent to produce medium density polypropylene foam sheets using a single screw extruder. The mechanical properties of the foam were similar in the machine direction and in the transverse direction. A better surface finish and a lower density was produced by using a commercial wrapping film as a cap layer. The process conditions and the die design data are presented and an attempt made to relate them to the product characteristics. 4 refs. NORWAY; SCANDINAVIA; USA; WESTERN EUROPE

Accession no.625216

Accession no.629140 Item 274 Patent Number: US 5527573 A 19960618 EXTRUDED CLOSED-CELL POLYPROPYLENE FOAM Park C P; Malone B A Dow Chemical Co. A closed-cell polypropylene foam, with at least 80% closed cells and a foamability characteristic of less than about 1.8 is disclosed. Also described are several methods for making such closed-cell polypropylene foams. USA

Accession no.625586

Item 277 Polymers, Laminations and Coatings Conference. Book 2. Conference Proceedings. Boston, Ma., 4th-7th Sept.1990, p.589-94. 6A EXTRUSION COATING OF POLYETHYLENE FOAM ONTO A WOVEN CLOTH WEB DeCoste L D Lowell,University (TAPPI) This paper examines in some detail the method of extrusion coating PE foam onto a woven cloth. An experiment is described in which the feasibility of foam extrusion coating was examined in order to produce a cost effective product. 4 refs. USA

Item 275 Journal of Vinyl and Additive Technology 2, No. 4. Dec.1996, p.349-357 EXTRUSION OF POLYPROPYLENE FOAMS WITH HYDROCEROL AND ISOPENTANE Behravesh A H; Park C B; Cheung L K; Venter R D

© Copyright 2004 Rapra Technology Limited

Accession no.614938

85

References and Abstracts

Item 278 Journal of Vinyl and Additive Technology 2, No.3, Sept.1996, p.258-62 COMPATIBILISER SYSTEM FOR EXTRUDED PE FOAM AND FILM Lee S-T Sealed Air Corp. The processing/product benefits of adding additives to extruded PE foam and film are discussed. Mention is made of the addition of metal oxide and fatty acid ester to improve foam product quality. 7 refs. USA

Accession no.614214 Item 279 Machine Design 68, No.19, 24th Oct.1996, p.53-6 FOAM GOES FROM BUMPERS TO BIKE HELMETS Luhtanen M BASF Corp. The advantages offered by the use of expanded polypropylene in automotive bumper cores and other applications are considered, and its properties are compared with other materials traditionally used in such applications in terms of impact strength, energy absorption, resilience, and compressive strength. USA

Accession no.609411 Item 280 Antec 96. Volume II. Conference proceedings. Indianapolis, 5th-10th May 1996, p.1955-8. 012 USE OF INERT GASES IN EXTRUDED MEDIUM DENSITY POLYPROPYLENE FOAMS Dey S K; Natarajan P; Xanthos M; Braathen M D Polymer Processing Institute; Borealis AS (SPE) Carbon dioxide gas was used as a physical blowing agent to produce medium density PP foam sheets using a single screw extruder. The mechanical properties of the foam were similar in the machine direction and in the transverse direction. A better surface finish and a lower density foam was produced by using a commercial wrapping film as a cap layer. The process conditions and die design data are presented in an attempt to relate to product characteristics. 4 refs. NORWAY; SCANDINAVIA; USA; WESTERN EUROPE

Accession no.607211 Item 281 Antec 96. Volume II. Conference proceedings. Indianapolis, 5th-10th May 1996, p.1948-54. 012 COMPATIBILISER SYSTEM FOR EXTRUDED

86

POLYETHYLENE FOAM AND FILM Lee S-T Sealed Air Corp. (SPE) The processing/product benefits derived by adding additives to extruded polyethylene (PE) foam and film are discussed. LLDPE (over 30 times expansion) requires an adequate cooling to stabilise the melt/gas system for optimal foaming efficiency. The presence of a small portion of high melting PEs (i.e. LLDPE, HDPE) causes flow instability after cooling to make surface defects in finished products. It was found that an addition of metal oxide and fatty acid ester improved processing latitude and foam product quality. This formula was also tested in film process on various ratios of LDPE/LLDPE and MDPE with promising results. It appears that this formula can allow us to accommodate post consumer resin (PCR) and to take advantage over PE price variation. 7 refs. USA

Accession no.607210 Item 282 Antec 96. Volume II. Conference proceedings. Indianapolis, 5th-10th May 1996, p.1941-7. 012 EFFECT OF BRANCHED STRUCTURE ON THE CELL MORPHOLOGY OF EXTRUDED POLYPROPYLENE FOAMS. I. CELL NUCLEATION Cheung L K; Park c B; Behravesh A H Toronto,University (SPE) An investigation of the cell nucleation and initial growth behaviours in the foam processing of the linear PP and the branched high-melt-strength PP has been performed. These materials were foamed in extrusion with two blowing agents, namely C02 and isopentane. In general, an increasing trend in the cell density was observed as the content of the blowing agent, either C02 or isopentane, was used. However, the cell morphologies for the two materials were quite different. A slightly lower cell population density was observed in the branched PP foams than in the linear VP foams. On the other hand, the phenomenon of cell coalescence was observed to be less significant in the branched PP foams. Most cells in the branched PP foams were closed, whereas in the linear PP foams they were connected to each other. Therefore, one can conclude that the stabilisation of cell structure in PP foams was achieved through branching in the polymer chain molecules. The experimental results indicated that the branched structure of PP played an important role in determining the cell morphologies through its effect on the melt strength, the melt elasticity, and the surface tension. 41 refs. CANADA

Accession no.607209

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 283 Antec 96. Volume II. Conference proceedings. Indianapolis, 5th-10th May 1996, p.1931-6. 012 DEVELOPMENTAL HDPE FOAM RESIN Firdaus V; Tong P P; Cooper K K Mobil Chemical Co. (SPE) The rheological characteristics of LDPE resins are well suited for producing foams. The high levels of long-chain branching provide excellent melt tension at relatively low viscosities. However, the low density of these resins is a limiting factor in certain applications where high stiffness may be needed. On the other hand, HDPE resins typically lack sufficient melt tension to provide a reasonable cell structure at the viscosities required for processing ease. Data are presented on a modified HDPE resin that approaches the excellent processability and foamability of HP-LDPE resins, while retaining the desirable physical properties of linear high density resins. Experiments on lab-scale as well as commercial scale equipment indicate that the processing and foaming behaviour of this developmental HDPE foam resin is significantly better compared to standard LLDPE or HDPE resins, and is similar to LDPE resins. The flexural modulus and break strength of the HDPE foam is more than twice that of the LDPE foam. 6 refs. USA

Accession no.607207 Item 284 Antec 96. Volume II. Conference proceedings. Indianapolis, 5th-10th May 1996, p.1862-7. 012 EXTRUSION OF POLYPROPYLENE FOAMS WITH HYDROCEROL AND ISOPENTANE Benhravesh A H; Park C B; Cheung L K; Venter R D Toronto,University (SPE) An experimental investigation was conducted to research the cell nucleation behaviour in the extrusion foam processing of PP using hydrocerol and isopentane. While the hydrocerol and isopentane are considered to function as the nucleating agent which determines the cell population density and as the blowing agent to control the volume expansion ratio respectively, both agents affected the cell population density. In addition, synergistic effects of these agents on the cell density were observed. In foam processing with hydrocerol, a higher cell population density was noted at lower processing pressures and at higher polymer flow rates. This phenomena is of interest since the cell density in general increases as the processing pressure is used in the foam processing. The results indicate that the nucleation in the foam processing with hydrocerol is governed by a heterogeneous mechanism; also, the quality of the mixing of the polymer and the agents as well as the amount of gas lost during the plastication of the

© Copyright 2004 Rapra Technology Limited

pellets in the barrel exerts a strong influence on the resulting cell density. 27 refs. CANADA

Accession no.607196 Item 285 Journal of Applied Polymer Science 62, No.1, 3rd Oct.1996, p.75-80 INVESTIGATION OF RADIATIONCROSSLINKED FOAM OF LDPE/EVA BLENDS Siqin Dalai; Chen Wenxiu Beijing,Normal University LDPE/EVA blend was irradiated using gamma-irradiation and then expanded by heat as a foamed material. The EVA content in the blend was optimised to form a gel. The effects of atmospheres and of irradiation dose rate were studied. The FTIR spectra of the foam revealed the oxidation level. The relations between gel fraction of LDPE/EVA blend, expansion ratio, apparent density, average cell diameter and tensile properties of the foam are discussed. 8 refs. CHINA

Accession no.607059 Item 286 Cellular Polymers 15, No.4, 1996, p.229-49 RE-ENTRANT TRANSFORMATION METHODS IN CLOSED CELL FORMATION Martz E O; Lee T; Lakes R S; Goel V K; Park J B Iowa,University The transformation of closed cell polymethacrylimide and LDPE foams are described in an attempt to impose reentrant structures on them. New methods of achieving permanent, triaxial compression were developed. 9 refs. USA

Accession no.603815 Item 287 Plastics and Rubber Weekly No.1653, 13th Sept.1996, p.10 OMAM’S FOAMED PP PROCESSES LIKE PS Thermoformable foamed PP sheet that processes with the same drawdown, sag and cycle times as PS has been manufactured by Omam using new PP blends and Safoam carbon dioxide blowing agents from Reedy International. Oman has already produced monolayer PP sheet with a 40% density reduction and three layer sheet with a 50% density reduction. The trials have been carried out using blends of conventional PP and a new high melt strength PP grade developed by Montell. The Omam line used to produce the foamed PP sheet is conventional apart from

87

References and Abstracts

the die design which has been modified to ensure sufficient pressure is maintained on the melt. OMAM SPA EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.602644 Item 288 Journal of Vinyl and Additive Technology 2, No.2, June 1996, p.167-9 MICROCELLULAR FOAMING OF POLYPROPYLENE CONTAINING LOW GLASS TRANSITION RUBBER PARTICLES IN AN INJECTION MOULDING PROCESS Chicheng Wang; Cox K; Campbell G A Clarkson University Microcellular foams in PP containing rubber particles were produced in an injection moulding process. The foams were generated because of the thermodynamic instability and were controlled by the formation process. The effect of processing parameters on microcellular foaming was investigated in the injection moulding process. Injection speed and pressure were found to be less important factors but packing pressure played an important role in controlling the foam density. A critical packing pressure, about 5,000,000 Pa, was found to generate microcellular foams in the PP material system studied. Rubber particles inside the PP appeared to stabilise the microcellular foams. 13 refs. USA

Accession no.600853 Item 289 Patent Number: WO 9520622 A1 19950803 Japanese EXTRUDED PROPYLENE POLYMER RESIN FOAM Fukasawa Y; Hashimoto S Asahi Kasei Kogyo KK An extruded propylene polymer resin foam having a wall thickness of 20 mm or above, a density of 0.005-0.03 g/ cu.cm, an average cell diameter of 0.4-2.0 mm, and a closed cell content of 80% or above is disclosed. It has a large number of closed cells and is produced from a propylene polymer resin having such high viscoelastic characteristics that the biaxial elongation viscosity and the biaxial strain curing rate as defined by an equation are of given values. The foam is lightweight and has high cushioning characteristics and excellent mechanical strength. Hence it is cut into various forms and utilised in the fields of cushioning packaging materials, floating materials and heat insulation.

Item 290 Patent Number: US 5459169 A 19951017 UNCROSSLINKED POLYETHYLENE PARTICLES FOR THE PRODUCTION OF EXPANDED PARTICLES AND UNCROSSLINKED POLYETHYLENE EXPANDED PARTICLES Tokoro H; Tsurugai K; Sasaki H; Oikawa M JSP Corp. Uncrosslinked polyethylene particles are disclosed for the production of expanded particles that can easily and securely produce expanded particles which can be moulded without applying a special internal pressure, are excellent in mouldability, such as secondary expansion, fusion and dimensional accuracy, and have a high expansion rate. Also disclosed are uncrosslinked polyethylene expanded particles made of the uncrosslinked polyethylene particles. The uncrosslinked polyethylene particles are obtained by impregnating the above resin particles with an expanding agent, dispersing the resin particles in a dispersing agent in a closed vessel, and discharging the resin particles and the dispersing medium from the vessel at a temperature equal to or over the softening temperature of the resin particles into a lowpressure region. JAPAN

Accession no.596620 Item 291 Kunststoffe Plast Europe 86, No.6, June 1996, p.26-8 EXTRUDED PP PARTICLE FOAM Lesca C; Pohl M Despite its impressive potential, expanded polypropylene was until recently limited to specialist applications. The unstable foaming behaviour of conventional PP and its narrow processing window exclude the use of the conventional foaming technologies typically used for other polymers, such as polystyrene or low-density polyethylene. The autoclave process, which is suitable for foaming PP-based materials, on the other hand, requires centralised, complex, and expensive production facilities, which increases the costs for the prefoamed particle to a level that restricts the number of applications. Advances in foaming technology have resulted in a new group of PP-based materials (Higran, produced and developed by Montell) that can be foamed with conventional technologies. This permits a wide range of products to be produced. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; ITALY; WESTERN EUROPE

Accession no.596176

JAPAN

Accession no.598791

88

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 292 Plastics Formulating & Compounding 2, No.2, March/April 1996, p.6 COMPOUNDING WITH METALLOCENE PE MAKES NEW OPPORTUNITIES FOR PP Schut J H Some of the biggest commercial successes so far for metallocene-based polyolefins are said to be in alloys, blends and compounds, where they offer unique performance properties. Dissimilar polymers may be physically mixed with compatibilisers or chemically reacted during extrusion. One such compound combines two metallocene-catalyst PEs at different stages with conventional PP to make a highly flexible foam. The foam is FMP-2 (flexible metallocene-modified polyolefin) made by Sentinel Products based on a compound, developed for the application by Ferro. The latter’s compound uses an elastomeric mPE (below 0.89 density). This compound is then combined with other proprietary compounds and chemical cross-linked and foamed to give strength in a patent-pending Sentinel process. Details are given. SENTINEL PRODUCTS CORP.; FERRO CORP. USA

Accession no.595986 Item 293 Patent Number: WO 9516732 A1 19950622 Japanese CROSSLINKED FOAM AND PROCESS FOR PRODUCING THE SAME Matsumoto M; Okada K; Matsuo Y; Uchiumi A Mitsui Petrochemical Industries Ltd. The foam is produced by two-stage vulcanisation and foaming of a rubber compound comprising a chlorinated ethylene/alpha-olefin copolymer rubber having a chlorine content of 20 to 40 wt.% and a Mooney viscosity (ML14 at 121C) of 10 to 190, a triazinethiol, as a vulcaniser, an alkylammonium halide, as a vulcanisation accelerator, and a hydrazide blowing agent in such a manner that the vulcanisation temperature and time in the first stage are 120 to 140C and 5 to 10 min., respectively, while those in the second stage are 125 to 160C (at least 5C higher than that in the first stage) and 5 to 20 min., respectively, and the expansion ratio is 3 to 10. The foam can be brilliantly coloured, has excellent weather resistance, flexibility, appearance and shape retention and is particularly suitable for wet suits. JAPAN

Accession no.595838 Item 294 Patent Number: US 5462974 A 19951031 EXPANDABLE COMPOSITION AND PROCESS FOR EXTRUDED THERMOPLASTIC FOAMS Lee S-T Sealed Air Corp.

© Copyright 2004 Rapra Technology Limited

An expandable thermoplastic composition is disclosed for extrusion foaming wherein the composition comprises a polyethylene resin; a blowing agent, which is either ethane or a blend of carbon dioxide and either normal butane, isobutane, propane, ethane, or a mixture of any two or more of these hydrocarbons in admixture with the resin in a ratio of about one part blowing agent to about 10 parts resin; nucleation agent in an amount of from about 0.05-0.5 kg/100 kg of the resin; and glycerol monostearate ageing modifier in an amount of from about 0.5-5kg/100 kg of the resin. A process for extrusion foaming of the composition is also disclosed. USA

Accession no.594424 Item 295 Low Density Cellular Plastics: Physical Basis of Behaviour. London, Chapman & Hall, 1994, p.270-318. 6124 IMPACT RESPONSE Mills N J Birmingham,University Edited by: Hilyard N C; Cunningham A (Sheffield,Hallam University; ICI,Polyurethanes Group) This comprehensive chapter supplies a detailed analysis of the types of cellular material where the impact properties are the main reason for their use, such as foams used for protective purposes in packaging and other applications, e.g. protective helmets. The chapter includes detailed information and discussion on such aspects as: macroscopic deformation geometry; cell geometry and deformation mechanisms; impact properties and the relation of impact properties to microstructure, packaging design and complex impacts. 36 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.593838 Item 296 Polyurethanes 95. Conference Proceedings. Chicago, Il., 26th-29th Sept.1995, p.459-63. 43C6 ADVANCES IN FOAM ADHESION TO REFRIGERATOR LINERS AND OTHER SUBSTRATES Nichols J B; Bonekamp J; Miller R C Dow Chemical Co. (SPI,Polyurethane Div.) A study was made of the effects of foam formulation and process conditions and liner composition on the adhesion of HCFC-141b blown rigid PU foam thermal insulation to refrigerator liner protective layers made of ABS, highimpact PS (HIPS), PE and blends of HIPS and PE containing a compatibiliser and adhesion promoter. A tensile test was used to quantify the level of adhesion before and after thermal cycling, and the Brett mould was used for laboratory simulations of foam adhesion within

89

References and Abstracts

a refrigerator. Loss of adhesion was shown to occur after samples were repeatedly thermally cycled from a cold to a hot environment for several days. Levels of adhesion were found to vary in different parts of a refrigerator cabinet, but these variations could be minimised by the use of an adhesion promoter in the liner protective layer. 7 refs. USA

Accession no.592109 Item 297 Polyurethanes 95. Conference Proceedings. Chicago, Il., 26th-29th Sept.1995, p.390-6. 43C6 POLYURETHANE: THE MATERIAL OF CHOICE FOR OCCUPANT PROTECTION AND ENERGY MANAGEMENT Yu-Hallada L C; Kuczynski E T; Weierstall M BASF Corp.; Woodbridge Foam Corp. (SPI,Polyurethane Div.) A comparative study is made of the properties of energy absorbing foams used in passenger protection in cars, with particular reference to dynamic impact and compression strength. Materials examined include polyurethanes, PP, PS and polyphenylene oxide/PS. 7 refs. USA

Accession no.592098 Item 298 Patent Number: EP 710697 A1 19960508 PROCESS FOR PREPARING EXPANDED ARTICLES BASED ON ETHYLENECHLOROTRIFLUOROETHYLENE COPOLYMERS Vita G; Pozzoli M Ausimont SpA This involves mixing the copolymer with 0.5 to 2 wt.% of boron nitride, extruding the blend at 260 to 300C, injecting into the molten blend nitrogen at 50 to 150 atmospheres and lowering the pressure. The articles have high dielectric properties. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.591406 Item 299 Polyurethanes 95. Conference Proceedings. Chicago, Il., 26th-29th Sept.1995, p.314-23. 43C6 FIVE YEAR FIELD STUDY CONFIRMS ACCELERATED THERMAL AGEING METHOD FOR POLYISOCYANURATE INSULATION Christian J E; Desjarlais A; Graves R; Smith T L Oak Ridge National Laboratory; US,National Roofing Contractors Association (SPI,Polyurethane Div.) Permeably faced polyisocyanurate foam laminated board insulation blown with HCFC-141b and CFC-11 was

90

subjected to continuous field thermal performance monitoring for 5.5 years. Thin sliced specimens were prepared from these boards and laboratory k-factors were periodically measured on these core foam specimens. An accelerated method was developed for predicting full thickness lifetime thermal conductivities (in-service Rvalues) of permeably faced boards. The predictions of the accelerated ageing procedure are compared to the actual field performance of loose-laid boards under EPDM membranes in a low sloped roof installed in a Roof Thermal Research Apparatus at Oak Ridge National Laboratory. 33 refs. USA

Accession no.588968 Item 300 Patent Number: EP 702032 A2 19960320 CROSSLINKED FOAM STRUCTURES OF ESSENTIALLY LINEAR POLYOLEFINS AND PROCESS FOR MANUFACTURE Hurley R F; Kozma M L; Feichtinger K A Sentinel Products Corp. Disclosed are compositions utilising crosslinked polyolefin copolymers and exhibiting improved strength, toughness, flexibility, heat resistance and heat sealing temperature ranges as compared to conventional LDPE compositions. They also show processing improvements over LLDPE. The polyolefins, which are essentially linear, comprise ethylene polymerised with at least one alphaunsaturated C3 to C20 olefinic comonomer and, optionally, at least one C3 to C20 polyene, and exhibit, in an uncrosslinked sense, a resin density in the range of about 0.86 to 0.96 g/cu.cm., a melt index in the range of about 0.5 to 100 dg/min, a MWD in the range of from about 1.5 to 3.5 and a composition distribution breadth index greater than about 45% USA

Accession no.587814 Item 301 Plastics Technology 42, No.4, April 1996, p.51 MOULD EPP BEAD FOAM WITH AN INTEGRAL SKIN Naitove M The article describes the process of producing expanded polypropylene foam parts with a solid integral skin on one side, citing a bicycle helmet moulded from BASF’s Neopolen EPP bead, as an illustration. The self-skinning EPP process requires some modification of standard beadmoulding equipment, needing an extra steam chamber. Automotive interior trim is a potential application for the process. BASF CORP. USA

Accession no.587430

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 302 Modern Plastics International 26, No.4, April 1996, p.27-8 PP BEAD GETS “BOUNCE” FROM MARKET, TECHNOLOGY SHIFTS Leaversuch R D In the past decade, expandable PP bead has made a visible impact in automobile bumper cores, flotation devices and protective shape markets. Now the industry is bent on extending the rigid foam’s reach into automobile interiors, where impact and sound dampening protection are high priorities. BASF says EPP offers cost, energy-efficiency, handling and weight benefits. European OEMs are developing all-PP vehicle interior systems that include EPP padding, for example knee bolsters, headliners, pillars, side bodies and instrument panel systems. EPP’s benefits in shape packages include cushioning equal to that of PUR, precise conformity to shapes and 20% higher temperature performance than solid PP. BASF AG; KANEKA CORP. JAPAN; USA

Accession no.587310 Item 303 Handbook of Polymeric Foams and Foam Technology. Munich, Carl Hanser Verlag, 1991, p.187-242. 6124 POLYOLEFIN FOAM Park C P Dow Chemical Co. Edited by: Frisch K C; Klempner D (Polymer Technologies Inc.; Detroit,University) Expansion and crosslinking processes and blowing agents used in the preparation of low density polyolefin foams are examined. Properties of these foams are reviewed and related to structure, and major application areas are described. 148 refs. USA

Accession no.586709 Item 304 Cellular Polymers 15, No.1, 1996, p.1-13 COMPRESSION MOULDED ETHYLENE HOMO- AND COPOLYMER FOAMS. I. EFFECT OF FORMULATION Sims G L A; Khunniteekool C Manchester,University; UMIST PE and EVA foams were manufactured by a two-stage heat and chill compression moulding technique, which allowed more efficient utilisation of the platen area than other compression moulding process variants and which was suited to low density foam production. The interrelationships of base polymer type, crosslinking and blowing agent concentrations and physical properties of resultant foams were investigated. 13 refs.

© Copyright 2004 Rapra Technology Limited

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.586353 Item 305 Patent Number: US 5446072 A 19950829 EMULSION COMPOSITIONS FOR FLAMEPROOF FOAM SHEET Mitsutake T; Narisawa S Sumitomo Chemical Co.Ltd. These comprise components A to C, the amount of component B being 5 to 50 pbw per 100 pbw of A (based on solid content) and the amount of C being 50 to 350 pbw per 100 pbw of A (based on solid content). A is an emulsion of ethylene-vinyl ester copolymer, which is composed of 5 to 35 wt.% of ethylene and 95 to 65 wt.% of vinyl ester, and has a Tg of -25 to +15C and a tolueneinsoluble part of 30 wt.% or more. B is a thermal expansive hollow microbead and C is an inorganic filler. The emulsion has superior mechanical strength, crack resistance, water resistance, alkali resistance, blocking resistance, foaming property, embossing property and superior flame resistance and can be used for flameproof foam sheet for wallpaper. JAPAN

Accession no.585617 Item 306 Cellular Polymers III. Conference proceedings. Coventry, 27th-28th April 1995, paper 23. 6124 BALANCE OF FORMULATION, PROCESSING Sims G L A; Sirithongtaworn W UMIST (Rapra Technology Ltd.) The foaming of crosslinked PE with three exothermic blowing agent formulations and an endothermic blowing agent is investigated by a variety of compression moulding processes and under free atmospheric expansion. Processing conditions are varied and internal temperature profiles determined as a function of time and compared to decomposition characteristics of the individual blowing agents from gas evolution curves and differential scanning calorimetry. Resultant foams are characterised by density, gel content and cell structure. It is shown that blowing agent and process conditions should be selected to optimise expansion according to the processing method, and that carbon dioxide is a much less efficient blowing agent than nitrogen in crosslinked PE. Blowing agent system requirements for atmospheric expansion rely on using essentially unmodified azodicarbonamide to delay the onset of gas evolution until a significant level of crosslinking has built up in order to contain the gas and improve foaming efficiency. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.583898

91

References and Abstracts

Item 307 Cellular Polymers III. Conference proceedings. Coventry, 27th-28th April 1995, paper 14. 6124 INFLUENCE OF LOW MOLECULAR ADDITIVES ON GAS TRANSPORT PROPERTIES IN POLYETHYLENE FILMS AND FOAMS Nauta W J; Bouma R H B Twente,University; DSM Research BV (Rapra Technology Ltd.) During the extrusion of LDPE foams with isobutane as a blowing agent, substantial foam shrinkage can be encountered. A solution to the problem has been proposed and involves addition of specific additives to the material. The principles underlying this approach are discussed. It is shown that the additive, after migration to the foam cell surface, acts as a diffusion barrier, especially with respect to isobutane. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.583889 Item 308 Cellular Polymers III. Conference proceedings. Coventry, 27th-28th April 1995, paper 13. 6124 CELL STRUCTURE DEVELOPMENT IN COMPRESSION MOULDED CROSSLINKED POLYETHYLENE AND ETHYLENE-VINYL ACETATE FOAM Sims G L A; Khunniteekool C UMIST (Rapra Technology Ltd.) Crosslinked PE and EVA are produced by single- and twostage heat and chill compression moulding techniques. In all cases, blowing agent concentrations are maintained constant and crosslinking agent concentrations adjusted to give similar gel contents independent of base polymer. Relative density measurements of fully expanded foams produced either by single stage of the heat and chill process do not show any great variation with vinyl acetate content. However, relative density of partially expanded material after the first stage of the heat and chill process show a considerable decrease at higher vinyl acetate contents, resulting in a consequent lower expansion factor in the second stage. Cell structures of foams from single stage expansion, and after the cooling cycle of the first and second stage final expansion of the heat and chill process, are observed by scanning electron microscopy. Resultant micrographs are analysed to give mean cell size and cell distribution data. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.583888 Item 309 Advanced Materials Newsletter

92

18, No.3, 12th Feb.1996, p.2 PLASTIC HONEYCOMB FINDING USES IN TRANSPORTATION, STORAGE AND AEROSPACE Also widely used in boat building, an extruded PP honeycomb, designated Nida-Core, has cost and fabricating advantages over competitive core materials. Nida-Core, developed in France and now available in the USA from Nida-Core Corporation, is produced by an extrusion method and therefore differs from most other honeycombs. Brief details are noted. NIDA-CORE CORP. USA

Accession no.581422 Item 310 Journal of Applied Polymer Science 59, No.9, 28th Feb.1996, p.1489-92 NEW METHOD FOR PREPARATION OF LIGHTWEIGHT ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE (UHMWPE) FOAM Aydinli B; Tincer T Middle East,Technical University UHMWPE foam with an average density of 0.11 g/cu.cm. was obtained by extracting the solvent xylene with alcohol. The foams were characterised by density measurement and thermal and SEM analysis. 6 refs. TURKEY

Accession no.580933 Item 311 British Plastics and Rubber Jan.1996, p.4-5 DIRECT GAS FOAMING GIVES PP A PERFORMANCE EDGE OVER EPS Wirz R; Berghaus U Foamed PP film has potential for packaging applications requiring temperatures beyond those achievable with expanded PS. Thermoforming film in EPP is used to make containers and cups which combine high rigidity with relatively light weight. These characteristics, combined with excellent temperature stability, permit easier handling in situations involving filling with hot liquids or reheating of the contents. The physically-induced foaming process from Reifenhauser, which is based on direct gas injection technology, enables EPS and EPP products to be made on the same extrusion line. With this process the density of the film can be reduced substantially compared with conventional processes such as chemical blowing. A further advantage of the technology is the opportunity it affords for producing multilayer EPP films by coextrusion. REIFENHAUSER GMBH & CO. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.578164

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 312 Plastics World 54, No.1, Jan.1996, p.44/50 LOSING WEIGHT, GAINING FLEXIBILITY Schut J H Krupp Kautex’s revolutionary coextrusion foam blow moulding process reduces part density by 5-50%, saving material and adding strength. The process makes parts with two or three layers of foam and skin, using two or three extruders. Typically, skin and foam are of the same material, HDPE or PP, so flash can be reused in the product again. Krupp has worked with Borealis to tailor compounds of PE and PP with an endothermic blowing agent, Hydrocerol. Blow moulding machines on show at K’95 included a machine that can be configured either for packaging or for technical parts, a three-axis blow moulder, robotic manipulation of a 3-D parison, and a host of reheat stretch-blow moulding machines. Several machine makers stretch-blew PP bottles at K with extraordinary clarity. WORLD

Accession no.578125 Item 313 Cellular Polymers 14, No.6, 1995, p.461-83 EVALUATION OF FOAMS FOR HORSE RIDERS’ BODY PROTECTORS Mills N J; Gilchrist A Birmingham,University A detailed account is given of impact tests on body protectors, and prediction of the forces in body protector tests, including impact tests in the BETA 1 specification and in the BETA 2 standard. 18 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Item 315 Antec 95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2183-8. 012 EFFECT OF MORPHOLOGY ON MICROCELLULAR FOAMING OF SEMICRYSTALLINE POLYMERS Doroudiani S; Park C B; Kortschot M T; Cheung L K Toronto,University (SPE) The effect of crystalline morphology on the microcellular foaming of HDPE and PP and on the structure of the resulting foams was investigated. The results indicated that the morphology of semi-crystalline polymers has a great influence on the solubility and diffusivity of blowing agents and the cellular structure of the foam in microcellular processing. 33 refs. CANADA; USA

Accession no.571304 Item 316 Antec 95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2178-82. 012 PHYSICOCHEMICAL ANALYSIS OF POLYMERS USED IN THE LOST FOAM CASTING PROCESS Shivkumar S Y; Celotto M A Worcester,Polytechnic Institute (SPE) A study was made of the thermal degradation behaviour of PS foams used as patterns in the lost foam process for metal casting. The data indicated that the thermal degradation of the pattern had a strong effect on mould filling and casting quality. The use of other types of foam such as PE, PP, PMMA and styrene-methyl methacrylate copolymers to overcome problems encountered with PS foam patterns is discussed. 7 refs. USA

Accession no.577619

Accession no.571303

Item 314 Antec 95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2217-24. 012 GAS LOSS DURING FOAM SHEET FORMATION Lee S T; Ramesh N S Sealed Air Corp. (SPE)

Item 317 Macplas International Aug.1995, p.111-2 SINTERED POLYPROPYLENE FOAM FOR PASSIVE SAFETY ON CARS Romanini D; Addeo A Montell; CSI The ability to modify their structure and the good cost/ performance ratio makes polyolefins technically and commercially attractive for mechanical energy absorption. This is especially true for High Melt Strength (HMS) PP which allows continuous extrusion foaming. Physical expansion of PP, properties of foamed PP, and application examples are considered in detail, mechanical properties in particular being compared with other polymer foams.

The non-isothermal viscoelastic cell model was used to study foam growth in the continuous extrusion of low density foam sheet. Surface escape of blowing agent was successfully incorporated to describe the foaming efficiency. Reasonable agreement was obtained with experimental data for HCFC-22 blown LDPE foam in the sub-centimetre thickness domain. 11 refs. USA

Accession no.571311

© Copyright 2004 Rapra Technology Limited

EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.571201

93

References and Abstracts

Item 318 Patent Number: WO 9510447 A1 19950420 IMPROVEMENTS IN THE STRUCTURAL COMPOSITION OF CHEST-TYPE SURFBOARDS Reidl B M Inducel LTDA The improved structure comprises elongate members extruded from expanded PE structural foam and joined laterally to one another by means of a thermal fusion bonding process, which compacts the expanded PE, thus forming, at the laterally adjoining walls of the members, a corresponding number of rigid films oriented at right angles to bending stress applied to an upper or lower surface of the joined members, thus acting as girders having their greater direction of strength opposing the bending stress. A thermally laminated skin is disposed on both upper and lower surfaces of the joined members, forming a sandwich assembly, which is subsequently subjected to complementary operations of coating the top, bottom and side edges, as well as surface finishing and other customary operations. The sandwich assembly exhibits improved rigidity and elasticity with no increase of weight over conventional chest-type boards because the density of the foam forming the elongate members is about 20 Kg/cu.m., less than in conventional boards, while the density of the foam forming the skins is about 140 Kg/cu.m., much greater than that of conventional boards. The average density is, thus, in the region of conventional boards (36 to 42 Kg/cu.m.). BRAZIL

Accession no.568881 Item 319 Patent Number: US 5407965 A 19950418 CROSS-LINKED ETHYLENIC POLYMER FOAM STRUCTURES AND PROCESS FOR MAKING Park C P; Chum P S; Knight G W Dow Chemical Co. Disclosed is a crosslinked ethylenic polymer foam structure of an ethylenic polymer material of a crosslinked, substantially linear ethylenic polymer. The ethylenic polymer in an uncrosslinked state has (a) a melt flow ratio greater than or equal to 5.63; (b) a molecular weight distribution defined by a given equation; and (c) a critical shear rate at onset of surface melt fracture of at least 50% greater than the critical shear rate at the onset of surface melt fracture of a linear ethylenic polymer having about the same melt flow ratio and molecular weight distribution. Further disclosed is a process for making the above foam structure.

GENERATION OF CUSHION CURVES FROM ONE SHOCK PULSE Burgess G Michigan,State University Three methods for generating performance information relative to the shock absorbing ability of cushioning materials are discussed. Data are given for drop tests for PE foam. 6 refs. USA

Accession no.567696 Item 321 Patent Number: US 5416129 A 19950516 CLOSED CELL, LOW DENSITY ETHYLENIC POLYMER PRODUCED WITH INORGANIC HALOGEN-FREE BLOWING AGENTS Chaudhary B I; Eschenlauer G; Marks B S Dow Chemical Co. An uncrosslinked foam having a density of less than 150 kg/cu.m. is prepared from, e.g. uncrosslinked LDPE, using inorganic blowing agents, such as carbon dioxide, argon or mixtures thereof. The ethylenic polymer with a suitable melt tension is extruded using 100% inorganic blowing agent. USA

Accession no.567481 Item 322 International Polypropylene Conference. Conference Proceedings. London, 24th-25th Oct.1994, p.156-64. 42C12 FOAM SANDWICH FOR AUTOMOTIVE BODY PANELS Atkinson P; Bagdatlioglu I BASF UK Ltd.; Plastic Design Solutions UK (Institute of Materials; BASF AG; European Chemical News; Montell Polyolefins) Foam sandwich has seemed for many years to have had much to offer, and yet has rarely been exploited commercially. Details are given of how a foam sandwich bootlid for the Ford Escort CE14 Cabriolet was designed, manufactured and tested. During the project, much was learned about the injection process as well as the properties and failure modes of composite foam sandwich panels. FORD MOTOR CO. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.564893

USA

Accession no.567861 Item 320 Packaging Technology & Science 7, No.4, July-Aug.1994, p.169-73

94

Item 323 Patent Number: WO 9508433 A1 19950330 German PROCESS FOR MAKING ARTICLES FROM EPP FOAM

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Simon R H; Weidler D Mankiewicz Gebr.& Co. A process is described for making foam mouldings of polyolefins, especially articles of expanded polypropylene particle foam (EPP) by welding the foam particles at temperatures above the softening region of the polyolefin using a device consisting of mould halves surrounding a mould shape, a filler, and steam chambers and steam nozzles in which an additional mould component with a perforated structure is inserted into the mould shape bearing in particular on the inside of the mould half away from the filler and which is permeable to steam and distributes it with the most uniform surface structure possible. The mould component is, in particular, a sieve, grid or non-woven. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.564062 Item 324 Cellular Polymers II. Conference proceedings. Edinburgh, 23-25th March 1993, paper 29. 6124 SHAPE MOULDABLE POLYPROPYLENE PARTICLE FOAMS: PROGRESS REVIEW Cousin J R BASF plc (Rapra Technology Ltd.) The European demand for expanded PP has grown considerably. New raw material and moulding capacity has come on stream, and further additions are announced for early 1994 start-up. The automotive industry has seen the strongest growth followed by reusable transit packaging, disposable packaging for very fragile goods, and leisure. Processing technology has been improved. The development of the European market since 1991 is described, with particular emphasis on processing technology and marketplace applications. Recycling is also discussed, and future prospects reviewed. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.562737 Item 325 Cellular Polymers II. Conference proceedings. Edinburgh, 23-25th March 1993, paper 21. 6124 PREDICTION OF PACKAGING CUSHION CURVES AND HELMET LINER RESPONSES Loveridge P; Mills N J Birmingham,University (Rapra Technology Ltd.) A method for the prediction of cushion curves for polymer packaging foams from a single impact stress-strain curve is proposed. The method is valid if there is a master curve for the increasing stress part of the stress-strain curve. For closed-cell polymer foams that deform by yielding

© Copyright 2004 Rapra Technology Limited

or brittle fracture there is a master curve. For viscoelastic polyolefin foams, the divergence from the master curve is under 10%. Consequently, there exists a rapid method of evaluating the cushioning properties of any new cellular foam. More complex geometry foam impacts are analysed, and it is shown that a simple linear loading relationship is a good approximation to the forcedeformation curve. 15 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.562733 Item 326 Cellular Polymers II. Conference proceedings. Edinburgh, 23-25th March 1993, paper 10. 6124 STRUCTURAL CHARACTERISATION OF EXTRUDED POLYOLEFIN FOAMS MADE USING A CHEMICAL EXPANSION SYSTEM Shishesaz M R; Hornsby P R Brunel University (Rapra Technology Ltd.) The structural characterisation of extruded foam profile made from PP and PP/PE blends containing chemical blowing agents is considered. Emphasis is given to the influence of blowing agent concentration on the melt rheology of foamable compositions combined with the effects of die geometry and processing conditions on the resultant density in the foamed state, before and after cooling of the melt. Cellular structure is discussed in terms of the relative levels of open and closed cell content, the uniformity of cell distribution, determined by mercury penetration, porosimetry and microscopic techniques, and microstructural characterisation of the semi-crystalline polymeric phase. 7 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.562723 Item 327 Patent Number: US 5405883 A 19950411 ETHYLENE POLYMER FOAMS BLOWN WITH ISOBUTANE AND 1,1-DIFLUOROETHANE AND A PROCESS FOR MAKING Park C P Dow Chemical Co. Disclosed is an ethylene polymer foam structure having enhanced processing and physical properties. The foam structure comprises an ethylenic polymer material and a blowing agent of isobutane and 1,1-difluoroethane. Further disclosed is a process for making the foam structure. USA

Accession no.562424

95

References and Abstracts

Item 328 Patent Number: US 5399592 A 19950321 ETHYLENE POLYMER FOAMS BLOWN WITH ISOBUTANE AND 1,1,1-TRIFLUOROETHANE OR 1,1,1,2-TETRAFLUOROETHANE AND A PROCESS FOR MAKING Park C P Dow Chemical Co. Disclosed is an ethylene polymer foam structure having enhanced processing and physical properties. The foam structure comprises an ethylenic polymer material and a blowing agent. The blowing agent has a primary blowing agent of isobutane and a secondary blowing agent of 1,1,1trifluoroethane, 1,1,1,2-tetrafluoroethane, or a blend of the two. Further disclosed is a process for making the foam structure.

Item 331 Plastics Industry News (Japan) 41, No.7, July 1995, p.5 LLDPE FORMED MATERIAL JSP has started marketing a cushioning material based on non-crosslinked LLDPE, which is easy to recycle. A non-fluoride foaming agent is used. LLDPE is inflated by about 38 times using carbonate gas and air as the foaming agent. JSP has installed large-scale foaming equipment to cut the cost of production. The electric appliance and automotive sectors have started using the recyclable cushioning material. This abstract includes all the information contained in the original article. JSP CORP. JAPAN

Accession no.557876

USA

Accession no.562349 Item 329 Antec 95. Volume I. Conference proceedings. Boston,Ma., 7th-11th May 1995, p.406-10. 012 MICROCELLULAR FOAMING OF POLYPROPYLENE CONTAINING LOW GLASS TRANSITION RUBBER PARTICLES IN AN INJECTION MOULDING PROCESS Wang C; Cox K; Campbell G A Clarkson University (SPE) The effect of processing parameters on microcellular foaming in the injection moulding process is investigated. Injection speed and pressure are less important factors, but packing pressure plays an important role in controlling the foam density. A critical packing pressure - about 5X106 Pa - is found to generate microcellular foams in the PP material system. Rubber particles inside the PP seem to stabilise the microcellular foams. 13 refs. USA

Accession no.558858 Item 330 Patent Number: WO 9502632 A1 19950126 ETHYLENE POLYMER FOAMS BLOWN WITH ISOBUTANE Park C P Dow Chemical Co. These comprise an ethylenic polymer and a blowing agent, which contains a primary blowing agent of isobutane and a secondary blowing agent of 1,1,1-trifluoroethane, 1,1,12-tetrafluoroethane or a blend thereof. They exhibit enhanced processing and physical properties. USA

Accession no.558493

96

Item 332 Patent Number: US 5391581 A 19950221 PRODUCTION METHOD OF FOAMED PARTICLES OF UNCROSSLINKED ETHYLENEBASED RESIN Kuwabara H; Tsurugai K; Oikawa M; Sasaki H; Shioya S JSP Corp. The foamed particles, which have a high expansion ratio and are free from the formation of fine cells, are made by dispersing particles of the resin obtained using, as a base resin, an ethylene/alpha-olefin copolymer containing, as a comonomer component, 1.0 to 10 wt.% of an alphaolefin having 4 to 10 carbon atoms, in a dispersion medium in the presence of a foaming agent in a closed vessel, heating the resulting dispersion to impregnate the resin particles with the foaming agent and then releasing the resin particles into a region of pressure lower than the internal pressure of the vessel at a foaming temperature not lower than the softening temperature of the resin particles, thereby expanding the resin particles. An aliphatic hydrocarbon and/or alicyclic hydrocarbon and carbon dioxide are used in admixture as the foaming agent in amounts satisfying specific equations. JAPAN

Accession no.557412 Item 333 Patent Number: US 5387620 A 19950207 CROSS-LINKED ETHYLENIC POLYMER FOAM STRUCTURES AND PROCESS FOR MAKING Park C P; Chum P-W S; Knight G W Dow Chemical Co. A foam structure of crosslinked, linear ethylenic polymer is disclosed. The linear ethylenic polymer in an uncrosslinked state has a melt flow ratio of greater than or equal to 5.63, a molecular weight distribution of 4.63, and a critical shear rate at onset of surface melt fracture that is at least 50% greater than that of a linear ethylenic

© Copyright 2004 Rapra Technology Limited

References and Abstracts

polymer having the same melt flow ratio and molecular weight distribution. Further disclosed is a process for making the above foam structure. USA

Accession no.557033 Item 334 Patent Number: EP 662493 A1 19950712 POLYETHYLENIC FOAMING COMPOSITIONS AND MOULDED FOAMS Sugimoto H; Igarashi T; Nakatsuji Y; Tatsumi M; Chikanari K; Funakoshi S Sumitomo Chemical Co.Ltd. The compositions comprise 100 pbw of an ethylenic copolymer having glycidyl groups consisting of 20 to 99.9 wt.% of an ethylene unit, 0.1 to 30 wt.% of the unit of a glycidyl ester of an unsaturated carboxylic acid or unsaturated glycidyl ether and 0 to 50 wt.% of an ethylenically unsaturated ester unit other than glycidyl ester, 0.1 to 30 pbw of a carboxylic acid having 2 or more carboxyl groups and a molec.wt. of 1500 or less and 0.1 to 20 pbw of a foaming agent of the thermal decomposition type. Foams produced therefrom are lightweight and have excellent cleanness, uniformly foamed cells, high expansion ratio and excellent impact resilience. Composite foams having a foam layer moulded from a powder of the composition and a non-foam layer moulded from a composition powder containing a certain thermoplastic elastomer and multilayer moulded articles containing the moulded composite foam are also disclosed. JAPAN

Accession no.556365 Item 335 Patent Number: WO 9425255 A1 19941110 ETHYLENE POLYMER FOAMS BLOWN WITH 1,1-DIFLUOROETHANE AND METHOD OF MAKING SAME Tusim M H; Park C P; Malone B A Dow Chemical Co. Processes for making olefin polymer foam structures with 1,1-difluoroethane (HFC-152a) are disclosed. One foam structure is comprised of an ethylene polymer material, and is blown with a mixture of isobutane and 1,1difluoroethane. Another foam structure has a cross section of 2 inches (5 cm) or greater in one dimension and 18 inches (46 cm) or greater in the other dimension, and is blown with 75 mol % or more HFC-152a. Another foam structure is in coalesced strand form with a density of 1648 kg/cu.m, and is blown with a first blowing agent of 20-90 mol % 1,1-difluoroethane and 80-10 mol % of a second blowing agent selected from isobutane, n-butane, and propane. USA

Item 336 Patent Number: US 5369136 A 19941129 FOAM STRUCTURES OF ETHYLENIC POLYMER MATERIAL HAVING ENHANCED TOUGHNESS AND ELASTICITY AND PROCESS FOR MAKING Park C P; Stevens J C; Knight G W Dow Chemical Co. The ethylenic polymer material contains a linear ethylenic polymer having a specified melt flow ratio, a defined MWD and a critical shear rate at onset of surface melt fracture of at least 50% greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having similar characteristics. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures. They also have foam quality similar to those made with conventional LDPE but with enhanced toughness and elasticity. The foam structure may also be made in a foam bead form. USA

Accession no.552175 Item 337 Patent Number: US 5366675 A 19941122 FOAMABLE POLYETHYLENE-BASED COMPOSITION FOR ROTATIONAL MOULDING Needham D G A foamable composition useful for rotational moulding is described, which advantageously includes an ethylene vinyl ester copolymer as an additive. The additive beneficially has a higher melt index than the base resin of the composition. USA

Accession no.550649 Item 338 Rothrist, c.1995, pp.4. 12ins. 17/2/95. 42C11-6124 German; French; Spanish; English AIROFOM. ECONOMY WITH POLYETHYLENE FOAM Airofoam AG Airofom PA 230 is a non-crosslinked PE foam which while having a slightly lower temperature resistance than crosslinked types, is claimed to be substantially cheaper to process. It has a closed-cell structure and is available in rolls, sheets and fabricated products, or as a selfadhesive backed or laminated to other materials. A sample of the foam is included. SWITZERLAND; WESTERN EUROPE

Accession no.550136

Accession no.552295

© Copyright 2004 Rapra Technology Limited

97

References and Abstracts

Item 339 Antec 94. Conference Proceedings. San Francisco, Ca., 1st-5th May 1994, Vol.II, p.2197-8. 012 EFFECT OF PHYSICAL BLOWING AGENTS ON CRYSTALLISATION TEMPERATURE OF POLYMER MELTS Dey S K; Jacob C; Biesenberger J A Polymer Processing Institute (SPE) An experimental apparatus and procedure were developed to determine the crystallisation temperature reduction of semi-crystalline polymers in the presence of physical blowing agents in solution. Results for LDPE showed that carbon dioxide was more effective in lowering the crystallisation temperature than argon. Since the molecular weights of both blowing agents are not far apart, it could be concluded that carbon dioxide was more soluble than argon in the LDPE melt. Therefore carbon dioxide would be a preferred choice as a blowing agent for LDPE foam production. 3 refs. STEVENS INSTITUTE OF TECHNOLOGY USA

Accession no.549430 Item 340 Patent Number: US 5354402 A 19941011 METHOD OF PRODUCING A THERMOPLASTIC FOAM SHEET Luetkens M L; Pischke R D; Schubert J C Amoco Corp. A method of producing a thermoplastic foam sheet is described, comprising the step of foaming, by extrusion, a mixture of polystyrene and a thermoplastic reclaim material obtained from a multi-layer sheet manufacturing process, in which the thermoplastic reclaim material comprises polystyrene and a thermoplastic barrier resin selected from the group consisting of (a) copolymers of ethylene and vinyl alcohol, and (b) polymers comprising a copolymer of acrylonitrile, to produce a foam sheet having an upper and lower surface. USA

Accession no.549179 Item 341 Plastics & Rubber & Composites Processing & Applications 23, No.3, 1995, p.193-200 MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED CELL MICROCELLULAR ETHYLENE-PROPYLENE-DIENE TERPOLYMER(EPDM) RUBBER VULCANISATES - EFFECT OF SILICA FILLER AND BLOWING AGENT Guriya K C; Tripathy D K Indian Institute of Technology

98

The morphologies of the microcellular EPDM rubber vulcanisates were studied from SEM photomicrographs as a function of blowing agent concentrations. The results showed that nucleation occurred through zinc oxide and filler surfaces. The number of cells and their distribution varied with the incorporation of silica filler and changes in blowing agent concentration. Physical properties such as TS, EB, modulus, tear strength and specific gravity changed with blowing agent concentration. 25 refs. INDIA

Accession no.547299 Item 342 Patent Number: US 5348984 A 19940920 EXPANDABLE COMPOSITION AND PROCESS FOR EXTRUDED THERMOPLASTIC FOAMS Lee S-T Sealed Air Corp. An expandable thermoplastic composition is disclosed for extrusion foaming in which the composition comprises a polyethylene resin; a blowing agent comprising a blend of about 50 wt.% carbon dioxide and about 50 wt.% of either normal butane, isobutane, propane in admixture with the resin in a ratio of about one part blowing agent to about 10 parts resin; zinc oxide nucleation agent in an amount of about 0.05-0.5 kg/100kg of resin; and glycerol monostearate ageing modifier in an amount of about 0.55.0 kg/100 kg of resin. A process for extrusion foaming of the composition is also disclosed. USA

Accession no.547027 Item 343 Patent Number: US 5350544 A 19940927 METHOD OF PREPARING A CROSSLINKED, POLYETHYLENE FOAM PRODUCT BY SURFACE EXPANSION OF A FOAM Bambara J D; Glydon J A Earth & Ocean Sports Inc. A rigid foam sheet product is made by heating at least one surface of a crosslinked PE foam sheet material to a temp. sufficient to cause a slight surface post-expansion of the sheet material and contacting the heated, post expanded foam surface with a cold metal element to form a product with the desired, accurate thickness or having a desired three-dimensional design on the sheet material. USA

Accession no.546898 Item 344 Antec 94. Conference Proceedings. San Francisco, Ca., 1st-5th May 1994, Vol.II, p.1992-7. 012 MORE EXPERIMENTS ON THERMOPLASTIC FOAM NUCLEATION

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Lee S T Sealed Air Corp. (SPE)

to those made with conventional LDPE but with enhanced toughness and elasticity. The foam may be made in a foam bead form.

A study was made of nucleation in PE foams produced in a counter-rotating extruder using talc powders and masterbatches as nucleating agents and CFC and HCFC blowing agents. The results indicated the importance of shear force in nucleation, as proposed in the lump cavity nucleation model and demonstrated by melt temperature effects observed in these experiments. It was shown that shear enhancement via lump break-up was not a vital mechanism in nucleation. 6 refs.

USA

USA

Accession no.546556 Item 345 Antec 94. Conference Proceedings. San Francisco, Ca., 1st-5th May 1994, Vol.II, p.194650. 012 APPROXIMATE CELL-TO-CELL DIFFUSION MODEL FOR POLYETHYLENE FOAM Kundu D; Princell C; Haji-Sheikh A IMCOA; Texas,Arlington University (SPE) The mass diffusivity coefficient of isobutane blowing agent from LDPE foam was found using a onedimensional diffusion model of two concentric cylinders with Dirichlet boundary conditions. An average mass diffusivity coefficient was used to calculate the mass of isobutane remaining in the foam for different boundary conditions. The influence of temperature and additives on diffusion was also examined. The use of the mass diffusivity coefficient in assessing the flammability of PE foam in the post-extrusion period is discussed. 2 refs. USA

Accession no.546547 Item 346 Patent Number: US 5340840 A 19940823 FOAM STRUCTURES OF ETHYLENIC POLYMER MATERIAL HAVING ENHANCED TOUGHNESS AND ELASTICITY AND PROCESS FOR MAKING Park C P;Stevens J C;Knight G W Dow Chemical Co. The polymer material contains a linear ethylenic polymer having a melt flow ratio, I10I2, of 5.63 or above, a MWD, Mw/Mn, defined by the equation Mw/Mn less than or equal to (I10/I2)-4.63 and a critical shear rate at onset of surface melt fracture of at least 50% greater than that of a linear olefin polymer having about the same I2 and Mw/ Mn. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures and foam quality similar

© Copyright 2004 Rapra Technology Limited

Accession no.545839 Item 347 Patent Number: WO 9417133 A1 19940804 EXPANDABLE COMPOSITION AND PROCESS FOR PRODUCING EXTRUDED THERMOPLASTIC FOAM Lee S-T Sealed Air Corp. An expandable thermoplastic composition is disclosed for extrusion foaming which comprises a polyethylene resin; a blowing agent comprising a blend of about 50 wt.% of carbon dioxide and about 50 wt.% of either normal butane, isobutane, propane, or a mixture of any two or all three hydrocarbons in admixture with the resin in a ratio of about one part blowing agent to about 10 parts resin; zinc oxide nucleation agent in an amount of from about 0.05 to 0.5 kg per 100 kg of the resin; and glyceryl monostearate ageing modifier in an amount of from about 0.5 to 5 kg per 100 kg of the resin. A process for extrusion foaming of the composition is also disclosed. USA

Accession no.545767 Item 348 Plastics and Rubber Weekly No.1577, 17th March 1995, p.7 PLASTAZOTE LD 18 Plastazote LD 18 closed cell PE foam from Zotefoams lies at the heart of new life jackets from Seadog Lifesaving Appliances. The range is designed to pack down into a very small space. Using Plastazote means that the life jackets can be stored for a number of years with no deterioration in buoyancy, it is claimed. The LD 18 foam meets Solas Regulation 4. This abstract includes all the information contained in the original article. ZOTEFOAMS EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.545410 Item 349 Patent Number: WO 9421717 A1 19940929 PROCESS FOR MAKING ETHYLENIC POLYMER FOAM STRUCTURES Park C P; Stevens J C; Knight G W Dow Chemical Co. The polymer is a linear ethylenic polymer having a melt flow rate of 5.63, a specified MWD and a critical shear rate at onset of surface melt fracture of at least 50% greater than that at the onset of surface melt fracture of a linear

99

References and Abstracts

olefin polymer having the same MWD. The foam has toughness and elasticity similar to those of foam formed from conventional LLDPE without the poor dimensional stability and foam quality associated therewith and has foam quality similar to that of conventional LDPE but with enhanced toughness and elasticity. The foam is produced in bead form.

blowing agents, generally hydrocarbons, in order to meet the stricter environmental pollution control regulations. This means adapting the polymer chemistry as well as the plant, mould and process technology, but also mental habits to meet the new situation. The most important modifications necessary to achieve these aims are described.

USA

EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.543530

Accession no.538982 Item 350 Patent Number: US 5324753 A 19940628 PROCESS FOR THE PREPARATION OF FOAMED PROPYLENE POLYMER ARTICLES Lesca G; Romanini D; Vezzoli A Himont Inc. Foamed propylene polymer articles are prepared by subjecting pre-foamed beads, that consist essentially of propylene polymers having a melt strength from 5 to 40 cN, to thermoforming by sintering. USA

Accession no.541003 Item 351 Patent Number: US 5373027 A 19941213 DRY EXPANSIBLE SEALANT AND BAFFLE COMPOSITION AND PRODUCT Hanley J L; Boos R C Sika Corp.; DuPont de Nemours E.I.,& Co.Inc. A sealant and baffle component is disclosed for sealing and providing an acoustic baffle for cavities in the hollow structural components of a vehicle body or the like, which, during manufacture, is conveyed through a bake oven at an elevated temp. The component is made up of a metal ion neutralised ethylene/alpha beta ethylenically unsaturated carboxylic acid copolymer (ionomer), a blowing agent and a tackifier and, optionally, an additive polymer and a crosslinking agent. The blowing agent is selected to be activated at the temp. of the bake oven so that the shaped and formed component expands in the body cavity to seal the cavity and prevent ingress of moisture, dust and other contaminating materials and particles, as well as to form a sound barrier therein. USA

Accession no.539171 Item 352 Plastverarbeiter 45, No.12, Dec.1994, p.86/90 German ALTERNATIVES FOR PE INSULATING FOAM PRODUCTION Henzler W CFC-based blowing agents used to date in the production of PE insulating foam must be replaced by alternative

100

Item 353 Patent Number: US 5314926 A 19940524 HYDROFLUOROCARBON COMPOSITIONS AS BLOWING AGENTS FOR CELLULAR PLASTICS Robin M L; Iikubo Y; Register W D; Rose R S Great Lakes Chemical Corp. Blowing agents for use in foamable plastics such as polystyrene, polyvinyl chloride, polyethylene and other non-polyisocyanate-based foams are described, comprising a mixture of 1,1,1,2,3,3,3-heptafluoropropane in combination with one or more hydrocarbons or partially halogenated alkanes. In one aspect of the invention the hydrocarbon adjuvant is selected from the group consisting of propane, butane, isobutane, n-pentane, ipentane, neopentane, n-hexane, 2-methylpentane, 3methylpentane and 2,2-dimethylbutane. In another aspect of the invention the halogenated alkane is selected from the group consisting of ethyl chloride, HCFC-123, HCFC141b, HCFC-142b, HCFC-124, HCFC-225ca, HCFC225cb, HFC-152a, HFC-143a, HFC-134a, HFC-134, HFC-245ca, HFC-236ea, and HFC-245ea. USA

Accession no.536254 Item 354 Patent Number: US 5278196 A 19940111 HYDROFLUOROCARBON COMPOSITIONS AS BLOWING AGENTS FOR CELLULAR PLASTICS Robin M L; Iikubo Y; Register W D; Rose R S Great Lakes Chemical Corp. Blowing agents for use in foamable plastics such as polystyrene, polyvinyl chloride, polyethylene and other non-polyisocyanate-based foams are described, comprising a mixture of 1,1,1,2,3,3,3-heptafluoropropane in combination with one or more hydrocarbons or partially halogenated alkanes. In one aspect of the invention the hydrocarbon adjuvant is selected from the group consisting of propane, butane, isobutane, n-pentane, ipentane, neopentane, n-hexane, 2-methylpentane, 3methylpentane and 2,2-dimethylbutane. In another aspect of the invention the halogenated alkane is selected from the group consisting of ethyl chloride, HCFC-123, HCFC141b, HCFC-142b, HCFC-124, HCFC-225ca, HCFC-

© Copyright 2004 Rapra Technology Limited

References and Abstracts

225cb, HFC-152a, HFC-143a, HFC-134a, HFC-134, HFC-245ca, HFC-236ea, and HFC-245ea. USA

Accession no.535697 Item 355 Patent Number: US 5091435 E 19940510 CROSS-LINKABLE FOAMABLE POLYOLEFIN RESIN COMPOSITION Suzuki T; Kitagawa S; Nakayama T; Kuno T Tonen Chemical Corp. (This patent is a reissue (RE 34607). The composition described, capable of forming foams with excellent mechanical properties and heat resistance, is made of (a) 14-80 wt.% of a propylene-ethylene random copolymer having an ethylene content of 1.5-6 wt.%, (b) 10-60 wt.% of a propylene-ethylene random copolymer having an ethylene content of 0.2-1.0 wt.%, (c) 10-60 wt.% of a linear low-density polyethylene, and (d) 1-30 pbw, per 100 pbw of the above resin composition, of a foaming agent. JAPAN

Accession no.535371 Item 356 1993 Polymers, Laminations and Coatings Conference: Book 2. Conference Proceedings. Chicago, Il., 29th Aug-2nd Sept.1993,p.403-6. 6A MULTILAYER EXTRUSION DIE GEOMETRY FOR THERMOFORMED POLYPROPYLENE FOAM SHEETS AND BIAXIALLY ORIENTED FOAM FILMS Raukola J; Savolainen A Tampere,University of Technology (TAPPI) Because of the environmental demands of CFC-foamed products, and also in attempting to replace PS with more environmentally friendly and with more heat resistant polyolefins, development of a new foam technology was commenced. The intention was to develop a new twostage blown film line which could be used for both thermoformed PP foam sheets as well as for biaxially oriented PP foam films. In order to reach the accepted level of quality of foamed film and sheet, it is necessary to homogenise the material. This can be accomplished by effective mixing in the die. For this purpose, a rotorstator die has been developed. After its exit from the die, thermoformable foam tube is first rapidly cooled down prior to reheating for orientation. The results are encouraging: a homogeneous foam structure (bubble diameter of under 100 microns), no stripes, smooth solid skins (multilayer structure) and low density. 1 ref. FINLAND; SCANDINAVIA; WESTERN EUROPE

Item 357 Patent Number: WO 9413460 A1 19940623 OPEN CELL POLYPROPYLENE FOAM AND PROCESS FOR MAKING SAME Park C P Dow Chemical Co. A low density, dimensionally stable, open-cell, extruded propylene polymer foam is disclosed. It comprises an expanded propylene polymer material, the polymer comprising more than 50 wt.% of propylene monomeric units based upon the total weight of the propylene polymer material. The foam has a density of 96 kilograms or less per cubic meter and is greater than 20% open cell. The blowing agent comprises more than 85 wt.% of one or more organic blowing agents based upon the total weight of the blowing agent. USA

Accession no.532250 Item 358 Patent Number: WO 9413459 A1 19940623 EXTRUDED CLOSED-CELL PROPYLENE POLYMER FOAM AND METHODS OF MAKING THE SAME Park C P; Malone B A Dow Chemical Co. The foam has at least 80% closed cells and a foamability characteristic of less than 1.8. USA

Accession no.532249 Item 359 Antec 93. Conference Proceedings. New Orleans, La., 9th-13th May 1993, Vol.III, p.30336. 012 TEMPERATURE EFFECTS ON THERMOPLASTIC FOAM SHEET FORMATION Lee S T; Ramesh N S; Campbell G A Sealed Air Corp.; Clarkson,University (SPE) Temperature variations during the formation of LDPE foam sheet were investigated. A thermal model was coupled with a viscoelastic growth model, and an iterative finite difference technique was used to solve unsteady heat transfer equations and viscoelastic growth equations. The heat transfer characteristic time became comparable to the expansion time when the sheet thickness decreased to the millimetre range, during which foam thickness and density became sensitive to temperature effects. 12 refs. USA

Accession no.528849

Accession no.532433

© Copyright 2004 Rapra Technology Limited

101

References and Abstracts

Item 360 Patent Number: US 5276064 A 19940104 COLOURED EXTRUDED FOAM CROSSLINKED BACKER ROD Hartman S Industrial Thermo Polymers Ltd. The formation of extruded foam products from polyethylene such as backer rods is disclosed in this patent. Diazo condensation colour pigments have been found to be especially suitable as relatively fast crosslinking occurs after extrusion. It has also been found that using traditional inorganic colour pigments substantially impedes the cross-linking mechanism. A methodology for the production of these cross-linked products is also given. CANADA

Accession no.527812 Item 361 Patent Number: US 5304580 A 19940419 EXPANDABLE POLYOLEFIN RESIN COMPOSITIONS Shibayama K; Ogasa M; Arai T; Takahashi E Sekisui Chemical Co.Ltd. These comprise 40 to 100 wt.% of PP having a melt index of 0.5 to 12, 0 to 60 wt.% of PE having a melt index of 2 to 50, 0.5 to 10 pbw of a di(meth)acrylate of an aliphatic dihydric alcohol having a methylene group with 2 to 18 carbon atoms between the (meth)acryloyloxy groups at both ends per 100 pbw of the combination of the two resins and 1 to 50 pbw of a thermally decomposable blowing agent. They also preferably comprise 0.5 to 5 pbw of a monofunctional monomer. Foams produced therefrom exhibit excellent heat resistance, toughness and mouldability and are homogeneous in appearance. JAPAN

Accession no.526299 Item 362 Patent Number: US 5296182 A 19940322 METHOD FOR MAKING FORMED LAMINATE Thary C Creme Art Corp. A formed laminate is made by relative movement of first and second contoured mould surfaces toward each other to compress a flexible sheet and vertically spaced film with a foamable liquid mixture therebetween that has substantially completed expansion but not yet substantially cured so as to form the flexible sheet and provide a collapsed foam layer bonded to the sheet. The flexible sheet is preferably porous cloth, vinyl or leather. A film which is preferably a nonadherent plastic such as PE is preferably positioned in a vertically spaced relationship with the flexible sheet either above or below the sheet with the foamable liquid mixture received therebetween for the expansion prior to the compression that provides the formed laminate. The formed laminate

102

can be used for clothing and is preferably made by a quick reacting type foamable liquid mixture which expands in about 8-25 seconds, preferably in about 10-15 seconds. USA

Accession no.519334 Item 363 Polymer Engineering and Science 34, No.10, May 1994, p.794-8 EFFECT OF PRELOADING ON THE MECHANICAL PROPERTIES OF POLYMERIC FOAMS Ozkul M H; Mark J E Istanbul,Technical University; Cincinnati,University Rigid foam PS, PU, and phenolic resin, and the semirigid foam of PE were examined with regard to their mechanical properties. The effects of preloading the foams on their mechanical properties are discussed. TURKEY; USA

Accession no.517604 Item 364 Patent Number: US 5292465 A 19940308 PROCESS FOR PREPARING LIGHTWEIGHT, RIGID COMPOSITE FOAMED MOULDED ARTICLE Kobayashi T; Watari M; Inoue T Mitsui Petrochemical Industries Ltd. The foamed article is made by placing a skin material in an upper mould for stamping mould kept at a temperature of 10 to 50C, feeding molten PP containing a foaming agent kept at a temperature of not lower than the decomposition temp. of the foaming agent and within the range of 180 to 240C onto a surface of a lower mould for stamping mould kept at a temp. of 30 to 80C and closing the mould within 10 sec after feeding of the composition to clamp the moulds at a pressure of 20 to 70 kg/sq.cm. The upper mould is then lifted before a thickness of each of the hardened layers formed on both surfaces of the composition layer reaches 1.0 mm to open the mould at a distance between the upper mould and lower mould of 1.1 to 2 times of the thickness of a flat portion having neither boss nor rib in the layer thereby to foam the composition and the foamed substrate is then cooled. JAPAN

Accession no.515834 Item 365 British Plastics and Rubber May 1994, p.4-5 GAS INJECTION REPLACES BLOWING AGENTS FOR FOAMED CABLE INSULATION Siebe Engineering has developed a process for foaming cable insulation without chemical blowing agents. In the Siebe process the melt is foamed by dispersing nitrogen

© Copyright 2004 Rapra Technology Limited

References and Abstracts

or carbon dioxide into it and allowing the gas to expand freely. The company claims material cost savings, improved product quality and faster line speeds. The physical foaming process takes place in an extruder with a conventional feed zone followed by a two-flighted barrier section and precise barrel temperature control. Immediately following the barrier section is a lower pressure zone where the gas injection takes place. A sophisticated process control loop is required to handle all the variables required to control the process. SIEBE ENGINEERING EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

Item 369 Patent Number: EP 588321 A1 19940323 PROCESS FOR THE PREPARATION OF FOAMED PROPYLENE POLYMER ARTICLES Lesca G; Romanini D; Vezzoli A Himont Inc. Pre-foamed beads consisting essentially of propylene polymer having a melt strength of from 5 to 40 cN are thermoformed by sintering. USA

Accession no.509845

Accession no.514682 Item 366 Japan Chemical Week 35, No.1773, 28th April/5th May 1994, p.12 EXPANDABLE PP-BEAD CAPACITY TO BE DOUBLED OVERSEAS Details are given of planned capacity increases in expandable polypropylene by the JSP Group, in both the US and Europe. A doubling of combined production capacities is planned for the material which is used in the foam of automotive bumper core materials. JSP GROUP; JSP CORP.; JSP INTERNATIONAL EUROPE-GENERAL; USA

Accession no.511975 Item 367 Patent Number: US 5288762 A 19940222 CROSSLINKED ETHYLENIC POLYMER FOAM STRUCTURES AND PROCESS FOR MAKING Park C P; Chum P-W S; Knight G W Dow Chemical Co. The ethylenic polymer has, in the uncrosslinked state, specified melt flow ratio, MWD and critical shear rate at the onset of surface melt fracture. USA

Accession no.510202 Item 368 Revista de Plasticos Modernos 67, No.452, Feb.1994, p.185-91 Spanish NEW POSSIBILITIES WITH POLYPROPYLENE Jung N E BASF Espanola SA Developments by BASF in high-impact propylene copolymers produced by reactive blending, random propylene copolymers, glass fibre-reinforced PP composites and PP foams are reported. Properties and applications of these materials are described. 4 refs. BASF AG EUROPEAN COMMUNITY; GERMANY; SPAIN; WESTERN EUROPE

Item 370 Patent Number: US 5286428 A 19940215 POLYPROPYLENE RESIN FOAMED SHEET FOR THERMOFORMING AND PROCESS FOR PRODUCING THE SAME Hayashi M; Doi T; Matsuoka K Sekisui Kaseihin Kogyo KK The sheet contains 10 to 50 wt.% of an inorganic fine powder, has a density of 0.2 to 1.2 g/cm and a thickness of 0.2 to 3 mm. It also has a percent shrinkage of 5 to 30% in each of the longitudinal and crosswise directions on heating at 190C for 30 min., the ratio of residual rate in the longitudinal direction to that in the crosswise direction being from 1:0.7 to 1:1.1. The sheet is produced by extruding and foaming a compounded resin from a ring die of an extruder and taking off the extruded tubular foamed sheet along a cylindrical drum, whose diameter is 2.0 to 3.0 times that of the ring die. JAPAN

Accession no.508761 Item 371 Patent Number: EP 585148 A1 19940302 ULTRA LOW DENSITY POLYOLEFIN FOAM HAVING A DENSITY OF ABOUT 0.6 TO 1.5 POUNDS PER CUBIC FOOT, FOAMABLE POLYOLEFIN COMPOSITIONS AND PROCESS FOR MAKING THE SAME Rogers J E; Kisner R D Astro-Valcour Inc. The foam comprises a heat-plastified mixture of a nonelastomeric ethylene homopolymer or copolymer or a propylene homopolymer, about 3 to 30 pbw of an elastomer, about 1 to 15 pbw of PS, a stability control agent, which is a partial ester of a long chain fatty acid with a polyol, higher alkyl amine, fatty acid amide or olefinically unsaturated carboxylic acid copolymer, and a hydrocarbon blowing agent having from 1 to 6 carbon atoms and a boiling point between -175 and 50C. USA

Accession no.507763

Accession no.510131

© Copyright 2004 Rapra Technology Limited

103

References and Abstracts

Item 372 Patent Number: EP 585147 A1 19940302 LOW DENSITY POLYOLEFIN FOAM HAVING A DENSITY OF ABOUT 0.9 TO 25 POUNDS PER CUBIC FOOT, FOAMABLE POLYOLEFIN COMPOSITIONS AND PROCESS FOR MAKING THE SAME Kisner R D Astro-Valcour Inc. The compositions consist of a heat-plastified mixture of an ethylene homopolymer or copolymer, about 3 to 30 pbw of an elastomer, a stability control agent, which is a partial ester of a long chain fatty acid with a polyol, higher allyl amine, fatty acid amide or olefinically unsaturated carboxylic acid copolymer, and a hydrocarbon blowing agent having from 1 to 6 carbon atoms and a boiling point between -175 and 50C. USA

Accession no.507762 Item 373 Patent Number: US 5281376 A 19940125 METHOD FOR PRODUCING PP RESIN ARTICLE HAVING SKIN MATERIAL LINED WITH FOAMED LAYER Hara T; Matsumoto M; Usui N; Matubara S Sumitomo Chemical Co.Ltd. The multi-layer article is made using moulds between which a cavity clearance is freely set. A skin material lined with foam is placed between the upper and lower moulds and molten PP containing a chemical blowing agent is supplied through a resin melt conduit in the lower mould when the cavity clearance is between (C plus 15) mm and (C plus 50) mm, where C is the thickness of the skin material lined with the foam. The upper mould is lowered at a specific rate and the molten resin is pressed at a specific pressure to fill the cavity ends with the molten resin to complete the moulding of the resin body. The body is pressed for a certain time to form a skin layer, the upper mould is lifted up to decrease the compression pressure of the skin material lined with the foam to a pressure lower than the blowing pressure of the PP resin to form and solidify the foamed body, the upper mould is lowered to apply pressure to the moulded article and finally the article is cooled in the mould. JAPAN

Accession no.505424 Item 374 Journal of Applied Polymer Science 51, No.5, 31st Jan.1994, p.841-53 PREPARATION OF FLAME-RETARDANT POLYETHYLENE FOAM OF OPEN-CELL TYPE BY RADIATION GRAFTING OF VINYL PHOSPHONATE OLIGOMER Kaji K; Yoshizawa I; Kohara C; Komai K; Hatada M

104

Japan Atomic Energy Research Institute; Sanwa Kako Co. Flame retardant PE foam was successfully obtained by grafting a vinyl phosphonate oligomer onto PE foam of an open-cell type using a simultaneous radiation grafting technique. The foam was impregnated with the oligomer and irradiated in a nitrogen atmosphere with an electron beam. The grafted foam thus obtained was found to pass the three most severe flammability tests that have to be cleared when the foam is to be used for materials where high flame-retardant property is required. No hydrogen cyanide was detected in burning exhaust gas of the grafted foam. 6 refs. JAPAN

Accession no.502456 Item 375 Polyurethanes 92. Conference Proceedings. New Orleans, La., 21st-24th Oct.1992, p.400-9. 43C6 ROOF SYSTEM EFFECTS ON IN-SITU THERMAL PERFORMANCE OF HCFC POLYISOCYANURATE INSULATION Christian J E; Desjarlais A O; Courville G; Graves R Oak Ridge National Laboratory (SPI,Polyurethane Div.) A long term research project to determine the long term thermal performance differences between polyisocyanurate foamed with CFC-11 and polyisocyanurate foamed with HCFC-123, HCFC-141b and two blends of HCFCs. Part of the work is to assess whether tests of less than a year on 10mm slices are useful in predicting the 12-20 year performance of 38-50 mm laminated polyisocyanurate boardstock. Also investigated were the effects of EPDM membrane above the insulation boards, i.e. whether it was black or white, loose laid, mechanically attached, asphalted, fully adhered by neoprene adhesive, or part of a built-up roof. The adhesive and built-up roof caused the greatest loss in R-value. 13 refs. USA

Accession no.498993 Item 376 Fire & Flammability Bulletin Oct.1993, p.5 FLAME-RESISTANT SPONGE DOES NOT PRODUCE POISONOUS GAS A method for producing a polyethylene sponge that is flame resistant and does not produce any poisonous gases when burned has been developed by the Research Development Corp. of Japan. The article supplies brief details of the product and its applications. RESEARCH DEVELOPMENT CORP. JAPAN

Accession no.497464

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 377 Plastics in Telecommunicatons VI. Conference Proceedings. London, 16th-18th Sept.1992, p.3/1-3/10. 6E IMPROVED METHOD FOR MEASURING THE STABILITY OF POLYOLEFINS Kuck V J AT & T Bell Laboratories (PRI) The laboratory-to-laboratory reproducibility of the isothermal oxidative stability procedure for measuring the oxidative stability of polyolefin insulation used in telecommunications applications has been improved from approximately 45% to approximately 85%. The improved protocol is described in some detail. 12 refs. USA

Accession no.496020 Item 378 Plastics in Telecommunications VI. Conference Proceedings. London, 16th-18th Sept.1992, p.1/1-1/10. 6E ADVANCES IN THE PRODUCTION OF HIGHLY EXPANDED LOW DIELECTRIC LOSS POLYOLEFIN INSULATION FOR CATV AND DATA TRANSMISSION Francis P C; Lips J; Tot B BP Chemicals Ltd.; BP Chemicals Belgium SA; Alcatel-Cablerie Seneffoise (PRI) This paper discusses the latest advances in manufacturing Community Antenna Television (CATV) cables via the gas injection process. Developments in polymer technology are discussed which have led to the production, by gas injection, of highly expanded, ultra low dielectric loss PE cable insulation for CATV and data transmission 3 refs. BELGIUM; EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.496018 Item 379 Fire & Flammability Bulletin July 1993, p.5 POLYETHYLENE SPONGE IS NON TOXIC IN FIRES An inflammable PE sponge that does not release any toxic gas when in contact with fire has been developed by Sanwa Kako Co.Ltd. The inner side of the polyethylene is chemically coated with a flame retardant using electron beam technology. The material is claimed to be suitable for use in car seats, furniture and cushions. Commercial production of the material is planned for late 1993. This abstract includes all the information contained in the original article.

© Copyright 2004 Rapra Technology Limited

SANWA KAKO CO.LTD. JAPAN

Accession no.488396 Item 380 Cellular Polymers 12, No.3, 1993, p.171-93 ARRESTED DIFFUSION PHENOMENON IN DENSE POLYETHYLENE FOAMS Briscoe B J; Chaudhary B I; Savvas T Imperial College The diffusion of gases from a polymeric matrix containing a dispersed and non-interconnected gaseous phase at a pressure higher than ambient was studied. Specifically, a dense LDPE foam expanded using high pressure nitrogen was characterised in terms of its mass and density changes as a function of time and its behaviour at triaxial (hydrostatic) compression. This foam was found to be degassing when stored at ambient temperature and pressure, but this process apparently occurred at a slow rate and was accompanied by a volume contraction of the material, leading to an increase in its apparent density. A decrease in compressibility was also observed with lapsed storage time, indicating a decrease in the void volume it contained. A model was used to simulate the mass transport process of the gas and the volume relaxation of the solid. 9 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.486089 Item 381 Plastics Industry News (Japan) 39,No.2,Feb.1993,p.20-1 NEW POLYMER APPLICATIONS Sekisui Kaseihin Kogyo Co. has developed a crystalline PETP based foam, Cell Pet, which exhibits high thermal resistance. Applications include packaging of food stuffs. The company’s PP-homopolymer foamed sheetings are used for producing food containers and daily/sundry goods packaging. PP foamed plates are used in industrial applications for insulating materials and cores. A modified PPO foam sheeting was recently produced and applications are being developed. SEKISUI KASEIHIN KOGYO KK JAPAN

Accession no.471956 Item 382 Journal of Cellular Plastics 28,No.6,Nov/Dec.1992,p.509-10 DOW INTRODUCES RECYCLED-CONTENT ETHAFOAM POLYETHYLENE FOAM THAT MEETS CONSISTENT QUALITY STANDARDS A brief report is presented on Dow’s Ethafoam 220 RP, a foam plank product which contains at least 15% recycled

105

References and Abstracts

PE from recovered material, has a nominal 2.2 lb/cu ft density and is designed for protective cushion packaging as well as general cushioning applications. Graphical information is provided on the dynamic cushioning performance of the foam. DOW CHEMICAL CO. USA

Accession no.470680 Item 383 Cellular Polymers 11,No.6,1992,p.429-49 STRUCTURE-PROPERTY RELATIONSHIPS IN THERMOPLASTIC FOAMS Clutton E Q; Rice G N BP Chemicals Ltd. The applicability of the Gibson and Ashby approach to structure-property relationships, particularly deformation mechanisms, is discussed in relation to a series of thermoplastic foams. The foams examined were based on LDPE, EVA, and a propylene copolymer. A full range of foam mechanical properties is discussed. 8 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.469053 Item 384 Rubber Chemistry and Technology 65,No.5,Nov./Dec.1992,p.932-55 INFLUENCE OF COMPOSITION AND PROCESSING HISTORY ON THE CELLULAR MORPHOLOGY OF THE FOAMED OLEFINIC THERMOPLASTIC ELASTOMERS Dutta A; Cakmak M Akron,University Foam extrusion of a series of dynamically vulcanised PP/ EPDM blends (Santoprene from Monsanto) by use of chemical blowing agents was studied. The results indicated that foaming occurred only within the thermoplastic phase and, for each composition, a limiting density existed which controlled the maximum volume expansion. This limiting density was controlled only by the composition and was independent of the blowing agent concentration, extrusion conditions and geometry. For the softest and hardest blends, maimum volume expansion was found to be about 20 and 100%, respectively. Significant differences in cell structure were also observed with change in the blend composition. 18 refs. MONSANTO CO.

CONDUCTORS Chan M G; Kuck V J AT & T Bell Laboratories Results are presented of studies of the oxidation of cable insulation consisting of a solid PE skin and PE foam in contact with a copper conductor. Measurements were made of the stability of PE containing stabilisers and metal deactivators in the presence of blowing agents and hydrocarbon oils, and interactions between stabilisers and blowing agents were analysed. USA

Accession no.466463 Item 386 Japan Chemical Week 33,No.1677,4th June 1992,p.8 PRODUCTION BASE FOR EXPANDED PP TO BE COMPLETED IN US JSP is due to complete in June a 120 t/y moulding plant for vehicle bumper cores based on P-Block expanded PP on the plant site of its US subsidiay J&V Foam Products. JSP has also begun to build a 1, 200 t/y expanded PP beads plant on the same site, scheduled to start up in January. The products will be marketed in Mexico and the US. JSP CORP. USA

Accession no.450912 Item 387 Antec 91.Conference Proceedings. Montreal,5th-9th May 1991,p.1304-7. 012 SHEAR EFFECTS ON THERMOPLASTIC FOAM NUCLEATION Lee S T SEALED AIR CORP. (SPE) Shear enhancement effects in foam formation can be understood through the modified cavity model. Shear force behaves as ‘catalyst’ to reduce energy barrier to allow a quik path from stable gas cavity to unstable bubble phase. It can be concluded that both shear rate and viscosity contribute to foam nucleation in the continuous foam extrusion process. Therefore, proper die opening and process conditions will help to optimise the foam product. 11 refs. USA

Accession no.448550

USA

Accession no.467855 Item 385 Macplas International May 1992,p.89-90 POLYETHYLENE FOAM FOR COPPER

106

Item 388 Antec 91.Conference Proceedings. Montreal,5th-9th May 1991,p.1330-3. 012 DEVELOPMENT OF MULTI LAYER FOAMED SHEET Egashira A;Yazaki T

© Copyright 2004 Rapra Technology Limited

References and Abstracts

MITSUBISHI PETROCHEMICAL CO.LTD. (SPE) A multi-layer foamed PP sheet was developed which efficiently inherits both characteristics of compounded and foamed material. Structure, manufacturing techniques, properties and applications of multi-layer foamed sheet are discussed. 3 refs. JAPAN

Accession no.448188 Item 389 Urethanes Technology 8,No.3,June/July 1991,p.26 NEW RETICULATION SYSTEM ON OFFER CPL Hartmeyer is offering its reticulation process for making open-celled rigid and flexible foams based on PU as well as PE and polyimide. The reticulation process is outlined. It is particularly useful for making mattresses and related products from the new CMHR (combination modified high resilience) foams. The company has also developed a method of reticulating foams which have been impregnated with activated carbon. These products are used to remove impurities from waste-water streams. The company’s other foam technologies are mentioned. CPL HARTMEYER GERMANY; SWITZERLAND; WESTERN EUROPE

Item 392 Modern Plastics International 21,No.9,Sept.1991,p.24 UNIQUE STRAND STRUCTURE PERMITS TAILORED CUSHIONING PROPERTIES Leaversuch R D Strandfoam, developed by Dow, is said to be an easy to shape polyolefin foam consisting of thousands of joined strands of foam. The structure is said to improve cushioning and insulation properties and may replace some open cell PU applications. The process is briefly described and utilises ethylene-acrylic acid in a PE carrier. DOW EUROPE SA SWITZERLAND; WESTERN EUROPE

Accession no.432164 Item 393 International Polymer Science and Technology 17,No.11,1990,p.T/50-1 HEAT STABILITY OF RADIATION CROSSLINKED PE FOAM Demaent’ev A G;Matyukhian G N;Kulikov Yu A;Belova E V; Preobrazhenskaya A A;Khramtsova T V Full translation of Plast.Massy,No.7,1990,p.34. 7 refs. EASTERN EUROPE; USSR

Accession no.431362

Accession no.445095 Item 390 Plastics Industry News (Japan) 37,No.10,Oct.1991,p.149 FOAMED PP SHEET Japan Synthetic Paper has developed a PP foaming process. The non-crosslinked PP is continuously extruded to produce foamed sheeting and the sheet is further vacuum moulded by the conventional process. The foamed PP is recommended for thermal insulation of hot water pipes, air conditioning plumbing and wire coverings. JAPAN SYNTHETIC PAPER CO. JAPAN

Accession no.435233 Item 391 Japan Chemical Week 32,No.1646,31st Oct.1991,p.5 HEAT RESISTANT PETP/PP FOAM PIONEERED Sekisui Plastics is reported to have developed two types of heat resistant plastics foam; one is PETP foam, capable of resisting temps. of up to 220C and the other is closedcell PP foam, resistant to temps. of up to 145C. Brief details are noted. SEKISUI PLASTICS CO.LTD. JAPAN

Accession no.435211

© Copyright 2004 Rapra Technology Limited

Item 394 Progress in Rubber and Plastics Technology 7,No.1,1991,p.38-58 STRUCTURE-PROPERTY RELATIONSHIPS IN THERMOPLASTIC FOAMS Clutton E Q;Rice G N BP CHEMICALS LTD. The applicability of the Gibson and Ashby approach, whereby deformation mechanisms are identified, to a range of thermoplastic polymer foams is explored. LDPE, EVA and PP foams were produced by the BXL Plastizote nitrogen expansion process. A full range of mechanical properties is discussed from the simpler aspects of modulus and strength to the complexities of creep and recovery performance. 8 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.430327 Item 395 Plastics Industry News (Japan) 37,No.7,July 1991,p.102 REACTIVE POLYMER Mitsubishi Petrochemical has developed a new type of reactive polymer, a copolymer of olefin and diene, for crosslinking of PP. By applying the reactive polymer, PP foam is easily produced and the polymer has improved

107

References and Abstracts

adhesion, printability and coating. The reactive polymer also makes the polyolefin moulded products recyclable. MITSUBISHI PETROCHEMICAL CO.LTD. JAPAN

Accession no.428192 Item 396 Antec 90.Plastics in the Environment:Yesterday,Today & Tomorrow.Conference Proceedings. Dallas,Tx.,7th-11th May 1990,p.717-20. 012 NOVEL FOAMABLE PP Bradley M B;Phillips E M HIMONT USA INC. (SPE) Demonstrations are given of the importance of extensional or elongational viscosity in the foam process. New polypropylenes are compared in extensional flow and it is shown how rheological differences allow the production of low density foam on tandem extrusion equipment. 6 refs. USA

Accession no.427660 Item 397 Japan Chemical Week 32,No.1628,27th June 1991,p.2 NEW POLYMER EASILY PRODUCES PP FOAM WITH IMPROVED PROPERTIES Mitsubishi Petrochemical is reported to have developed a new type of reactive polymer permitting the crosslinking of PP, which has so far been difficult. The material is a copolymer of olefin and diene, with the polyolefin sidechain having an unsaturated group. Very brief details are noted. MITSUBISHI PETROCHEMICAL CO.LTD. JAPAN

Item 399 Cellular Polymers.Conference Proceedings. London,20th-22nd March 1991,Paper 34. 6124 RECENT DEVELOPMENTS IN SHAPE MOULDABLE PARTICLE POLYOLEFIN FOAMS Cousins J R;Domas F BASF AG; BASF PLC (Rapra Technology Ltd.) Developments in mouldable particle PP foams are described, using the BASF product range as a basis. The moulding process is detailed, physical properties of mouldings produced from Neopolen P at densities of 20 to 60 kg/cu.m. are detailed and major end-use applications are indicated. The moulding sequence is also illustrated. EUROPEAN COMMUNITY; GERMANY; UK; WESTERN EUROPE

Accession no.421170 Item 400 Cellular Polymers.Conference Proceedings. London,20th-22nd March 1991,Paper 28. 6124 MECHANISM OF THE RECOVERY OF IMPACTED HDPE FOAM Loveridge P;Mills N J BIRMINGHAM,UNIVERSITY (Rapra Technology Ltd.) A study was made of the impact and recovery behaviour of three HDPE closed-cell foams with varying densities. Impact stress-strain curves were measured using a falling striker impact rig and the recovery monitored from 10s after the impact. Cell deformation was observed during compression and recovery using SEM. Recovery was found to occur by the viscoelastic straightening of the buckled faces and to be incomplete due to plastic deformation in the structure. 6 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.421166

Accession no.425651 Item 398 Japan Chemical Week 32,No.1622,16th May 1991,p.1 JSP EXPANDS MARKET FOR PP FOAM JSP Corp. is expanding market applications for P-Block, a non-crosslinked PP foam, as an automotive bumper core material. An ambitious market development plan will be undertaken this autumn following full-scale start-up of its new plant currently under construction. P-Block is also being used as protective packaging for computers and other precision machinery. JSP CORP. JAPAN

Accession no.424549

Item 401 Cellular Polymers.Conference Proceedings. London,20th-22nd March 1991,Paper 5. 6124 NOVEL FOAMABLE PP POLYMERS Bradley M B;Phillips E M HIMONT USA INC. (Rapra Technology Ltd.) A comparison is made between a 3.5 melt flow conventional polypropylene homopolymer (Profax 6523) and a 7.0 melt flow, high-melt-strength, foamable PP homopolymer in extensional flow. The importance of extensional or elongational viscosity in the foam process is demonstrated and the way in which the rheological differences permit the production of low-density foam on tandem extrusion equipment is shown. 6 refs. USA

Accession no.421140

108

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 402 Plastics Engineering 47,No.3,March 1991,p.82-4 NOVEL POLYPROPYLENES FOR FOAMING ON CONVENTIONAL EQUIPMENT Bradley M B;Phillips E M HIMONT USA INC. Polypropylene’s low elongational viscosity and poor melt strength have prevented its widespread use in extruded, low-density foams. However, significant improvements in PP technology have made possible the production of low-density foam on conventional equipment. This article demonstrates the importance of extensional or elongational viscosity in the foam process, compares new and conventional PPs in extensional flow, and shows how these rheological differences allow production of lowdensity foam on tandem extrusion equipment. USA

Accession no.420001 Item 403 Watford, 1990, pp.6. 12ins. 19/7/90. 42C11-6124-6L3 CLIMATUBE PIPE INSULATION BRITISH BOARD OF AGREMENT; NMCKENMORE (UK) LTD. Agrement Board.Certificate 90/2403 This certificate relates to Climatube extruded foam PE pipe insulation. It is used in the thermal insulation of water supply pipes and heating pipework. The insulation is semisplit for ease of fitting, and polychloroprene adhesive and climatape adhesive tape are supplied for sealing cut ends and joints. Thermal conductivity data are tabulated. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Item 405 Plastics Industry News (Japan) 37,No.1,Jan.1991,p.5 CROSSLINKED PE FOAM Hitachi Chemical is considering developments of new applications for its crosslinked PE foam. It has been used as roofing material, cushioning and insulation. It is a closed-cell type and does not absorb moisture or water, is chemical resistant and highly shock absorbant. It is easy to handle and may be processed using conventional equipment. Applications are expected to widen to meet future needs. HITACHI CHEMICAL CO. JAPAN

Accession no.414468 Item 406 Plaste und Kautschuk 37,No.2,Feb.1990,p.60-2 German ANISOTROPY OF INJECTION MOULDED POLYOLEFIN FOAMS Christova T V;Natov M A SOFIA,HIGHER CHEMICOTECHNOLOGICAL INSTITUTE Using the manufacture of PP battery cases as an example, the authors show how to produce thin-walled (2-5mm), foamed articles with good surface properties by means of low pressure injection moulding. Neopor 35 was used as the blowing agent. 5 refs. BULGARIA; EASTERN EUROPE

Accession no.411136

Accession no.416051 Item 404 Journal of Cellular Plastics 26,No.2,March/April 1990,p.118-22 PREPARATION AND POTENTIAL APPLICATIONS OF EVACUATED CLOSEDCELL PLASTIC FOAMS Jewett D M MICHIGAN,UNIVERSITY The manufacture of evacuated closed-cell PE foam and potential applications of these foams and of gasexchanged foams, which were exposed to fluorine in helium after evacuation, are described. The evacuated foams were prepared by rapid evacuation in a chamber to a pressure of 5 to 10mm Hg, during which the foam segments initially expanded and then rapidly relaxed to about their original dimensions as gas diffused out. Thermal insulation is considered to be a potential enduse. 3 refs.

Item 407 New Materials/Japan Nov.1990,p.15 FOAM EXPANSION TECHNOLOGY REQUIRES NO CHLOROFLUOROCARBONS JSP has developed a PP expansion moulding technology employing a mixture of carbon dioxide and air as the foaming agent, in place of chlorofluorocarbons. It reports that the method produces stable, high quality PP foam at a low cost. By the end of 1990, JSP plans to introduce the technology into its expandable PP bead production plant at its Kanuma factory in Tochigi Prefecture. This abstract includes all the information contained in the original article. JSP CORP. JAPAN

Accession no.410168

USA

Accession no.415674

© Copyright 2004 Rapra Technology Limited

109

References and Abstracts

Item 408 Plastics Technology 36,No.7,July 1990,p.27 HIGH-MELT-STRENGTH PP PERMITS FOAM SHEET EXTRUSION Gabriele M C Himont is to commercialise later in 1990 a new PP grade designed to overcome the material’s traditional melt strength weakness, which has largely precluded its application in extruded low density foams. The material does not, as yet, have a trade designation; details are given. HIMONT INC. USA

Accession no.410147

Himont’s PP resins with melt strength high enough to allow extrusion into foamed sheet on conventional lines may constitute the first serious alternative to foamed PS sheet. They may also be used to replace foamed PE; details are given. HIMONT INC. USA

Accession no.409284 Item 412 Kunststoffe German Plastics 80,No.8,Aug.1990,p.17-8 BEHAVIOUR OF POLYPROPYLENE FOAMED PLASTIC DURING RAPID DEFORMATION Drumm R;Klipfel W;Giesen K BASF AG

Item 409 Packaging (USA) 35,No.11,Sept.1990,p.63 CUSHIONING SYSTEM PRODUCES TRANSIT DAMAGE Larson M

A crash test rig was developed to simulate the high loads on components in and on street vehicles in the case of a collision. It provides profiles of deformation, energy dissipation and retardation as a function of time. The effect of test velocity and temp. on the behaviour of PP foam (Neopolen P) samples of various density was examined. 2 refs.

A furniture company is using sheets of PP foam, supplied by Ametek Microfoam, to protect upholstered furniture in transit. The sheeting is taped into pouches and used to surround the furniture before it is packed into corrugated cases. The company has reduced its corrugated use by 60%. AMETEK CORP.,MICROFOAM DIV.

EUROPEAN COMMUNITY; WEST GERMANY; WESTERN EUROPE

USA

Accession no.409408 Item 410 Plastics World 48,No.12,Nov.1990,p.19 POLYOLEFIN FOAM OUTPERFORMS PUR Lodge C Dow Plastics is to unveil a new resilient polyolefin foam, Strandfoam, which offers packagers of lightweight electronic equipment and components reduced package size, and savings in materials and shipping costs. Strandfoam is made of a special blend of PE and is produced by a proprietary extrusion process that yields fused strands of closed-cell foam with a network of air channels parallel to the foam strands. Strandfoam provides the required levels of protection with substantially smaller volumes of foam compared to urethane. DOW PLASTICS USA

Accession no.409379 Item 411 Modern Plastics International 20,No.12,Nov.1990,p.40/2 PP FOAM SHEET CAN BE EXTRUDED ON CONVENTIONAL EQUIPMENT

110

Accession no.407856 Item 413 Japan Chemical Week 31,No.1590,4th Oct.1990,p.2 PS/PE-COPOLYMER-BEAD FOAM ADOPTED AS ENERGY ABSORPTION MATERIAL FOR BUMPER Sekisui Plastics’ PS/PE copolymer-bead foam has been adopted as energy absorption material for use in automobile bumpers. The foam combines the stiffness of PS with the toughness of PE. The material will be marketed as a replacement for PP. SEKISUI PLASTICS CO.LTD. JAPAN

Accession no.406839 Item 414 Japan Chemical Week 31,No.1589,27th Sept.1990,p.14 CFC-FREE FOAMING PROCESS FOR PP BEADS DEVELOPED: JSP CORP. JSP Corp. has established a CFC-free foaming process for non-crosslinked expandable PP beads, trade named P-Block. An air/carbon dioxide-based foaming agent is used which causes no environmental problems. P-Block has strong thermal and oil resistance and has high-level repeated compressive strength. It has been used as core material for car bumpers and shock absorbing packaging. JSP CORP. JAPAN

Accession no.406660

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 415 Kunststoffe German Plastics 79,No.10,Oct.1989,p.101-3 POLYPROPYLENE FOAMED PLASTIC - A PACKAGING MATERIAL WITH SPECIAL PROPERTIES Haardt U G BASF AG (For German version see Kunststoffe,79,No.10, Oct.1989,p.1036-9). Polypropylene foams exhibit good cushioning behaviour, low density, high energy absorption and damping properties as well as good design potential. This article describes their processing characteristics and possible application areas. 1 ref. EUROPEAN COMMUNITY; WEST GERMANY; WESTERN EUROPE

Accession no.405378 Item 416 Polymer Engineering and Science 30,No.13,Mid-July 1990,p.783-97 LOW DENSITY FOAMS PRODUCED FROM SHEARED ULTRA-HIGH-MOLECULARWEIGHT POLYETHYLENE GELS Matthews F M;Hoffman D M LAWRENCE LIVERMORE NATIONAL LABORATORY Low density foam (0.02-0.09 g/cc) was produced from gels of ultra high molec.wt. PE (GUR and UHMW-1900) in solvents with melting points above ambient. Solvents were bibenzyl, naphthalene, durene, p-xylene, decalin, 1-chloronaphthalene and tetralin. The hot solutions were stirred at high speed to induce extended chain crystalline gels. These gels were cooled to solidify the solvent and then the solvent was extracted with alcohol or sublimed. Crystal structures were studied. Use of small particles of tungsten or carbon black as nucleating agents was investigated. 71 refs. USA

Accession no.405340

USA

Accession no.400897 Item 418 Polymer Degradation and Stability 24,No.4,1989,p.327-33 PROPERTY CHANGES IN INJECTION MOULDED POLYPROPYLENE STRUCTURAL FOAM Touleschkov N;Djoumaliisky S;Kotzev G BULGARIA,ACADEMY OF SCIENCES Isotactic PP (Buplen 7523) with AIBN (Genitron EPA) blowing agent was injection moulded on an in-line injection moulding machine KuASY 800/250 and on a two-stage Siemag Structomat 2000/7. Melt temp. was varied from 200 to 260C. The properties studied were density distribution, flow index and mechanical properties (TS, impact strength and residual deformation). Injection moulding caused specific structural changes in the PP including strong crosslinking, which affected the properties of the structural foam components. 5 refs. BULGARIA; EASTERN EUROPE

Accession no.399065 Item 419 Cellular Polymers 8,No.4,1989,p.259-76 MULTIPLE-IMPACT PERFORMANCE OF HIGH-DENSITY POLYETHYLENE FOAM Mills N J;Hwang A M H BIRMINGHAM,UNIVERSITY Strains in the 80-90% region are found to cause some permanent buckling of the cell walls, but the majority of the deformation recovers with 24h. A criterion for the performance of the foam in protective helmets is proposed. With HDPE foam the performance can deteriorate by 30% in a single severe impact, but even so, this is better than the PS foam widely used. 8 refs. BXL PLASTICS LTD.; COURTAULDS ADVANCED MATERIALS UK; WESTERN EUROPE

Item 417 Packaging Technology & Science 3,No.2,April/June 1990,p.117-22 EFFECTS OF MULTIPLE IMPACTS ON THE CUSHIONING PROPERTIES OF CLOSED-CELL FOAMS Totten T L;Burgess G J;Singh S P MICHIGAN,UNIVERSITY Details are given of the change in cell structure of a closecell foam due to multiple impacts and the range of application of cushion curves as they relate to reusable packaging. Cushion curves and stress-strain curves for up to 15 compressions were generated for three different moulded closed-cell PE foams.

Accession no.397457 Item 420 Modern Plastics International 20,No.3,March 1990,p.12/4 AIR DUCTS IN PP FOAM Hoechst have developed a process that sucks the parison onto the mould walls in blow moulding equipment, thereby producing lightweight hollow parts with good insulation properties. The process was developed for foamed PP air ducts for cars. A description is given in the article. HOECHST AG WEST GERMANY; EUROPEAN COMMUNITY

Accession no.394381

© Copyright 2004 Rapra Technology Limited

111

References and Abstracts

Item 421 Plaste und Kautschuk 36,No.6,June 1989,p.204-7 German INCREASING THE DIMENSIONAL STABILITY OF PRODUCTS MADE FROM FOAMED AND FILLED THERMOPLASTICS BY THE USE OF GAS COUNTERPRESSURE INJECTION MOULDING Piperov N L BULGARIAN ACADEMY OF SCIENCES The manufacture of products, e.g. containers and lids, made from filled foamed PE by gas counter pressure injection moulding was studied with special reference to the effect of production conditions on dimensional stability. Results obtained are discussed and evaluated. 7 refs. BULGARIA; EASTERN EUROPE

Accession no.393737 Item 422 Modern Plastics International 20,No.2,Feb.1990,p.12-3 AIR DUCTS ARE VACUUM-FORMED ON A BLOW MOULDING MACHINE Hoechst has developed a method moulding PP foam automobile air ducts that optimise air flow and also provide good sound and heat insulation. Machines are adapted to suck the parison onto the mould walls rather than to blow mould it. The process also uses a blowing pin operating in reverse mode to create a partial vacuum inside the moulding in order to roughen its inner surface. HOECHST AG WEST GERMANY; EUROPEAN COMMUNITY

Accession no.392333 Item 423 International Polymer Science and Technology 16,No.8,1989,p.T/65-7 PROPERTIES OF A PLASTIC FOAM BASED ON A MIXTURE OF HDPE AND LDPE Petrun’kin E B;Petrun’kina N V;Berlyant S M;Pleshanov V P 2 refs. (Full translation of Plast.Massy,No.2,1989,p.16). USSR; EASTERN EUROPE

Accession no.390618 Item 424 Kunststoffe German Plastics 79,No.3,March 1989,p.25-7 POLYPROPYLENE FOAMED PLASTIC Haardt U G BASF AG

112

(For German version see Kunststoffe,79,March 1989,p.256-9). Polypropylene foams exhibit high energy absorption over a wide temp. range, high temp. stability and good resilience and have a density which is circa 4050% lower than that of other plastics foams with comparable properties. These characteristics make PP very attractive for use in the car industry. This paper considers its use for energy absorbing foam cores in bumper systems. WEST GERMANY; EUROPEAN COMMUNITY

Accession no.389949 Item 425 Composites Plastiques Renforces Fibres de Verre Textile 29,No.3,May/June 1989,p.371-3 French OPTIMISED USE OF OMEGA REINFORCING MATERIALS Auge J M Examples are given of the use of extruded PE foam sections in conjunction with other polymeric materials in the production of triangular, semicircular, rectangular and trapezoidal profiles, e.g. beam-like structures in which the rigid support may be of GRP. The foam can be bonded with thermally-fusible adhesives or two-sided self adhesive tape affixed to the foam prior to fabricating. A standard range of the foam products is available, but other types can be tailor-made. SICOMIN Accession no.387436 Item 426 Midland,Mi., c.1988, pp.12. 11ins. 3/11/89. Form No.172-1246-88 AMS. 42C11-6124 DESIGN ENGINEER’S GUIDE TO ETHAFOAM POLYETHYLENE FOAMS. HOW A UNIQUE COMBINATION OF PROPERTIES OFFERS HUNDREDS OF PRODUCT DESIGN SOLUTIONS DOW CHEMICAL CO. The properties and characteristics of Ethafoam polyethylene foam are described. It is a tough, lightweight, closed cell PE foam, which is available in plank, sheet and round configurations, in a variety of strengths, densities and in three colours, white, blue and black and a pink antistatic form. Fire retardant grades are also available. Applications are illustrated which include cushioning, lining and sealing in the transport industry, insulating and sealing in the construction industry, buoyancy aids and recreational protective applications, and packaging and materials handling. USA

Accession no.386346

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 427 Journal of Applied Polymer Science 37,No.8,April 1989,p.2153-64 PREPARATION OF HYDROPHILIC POLYETHYLENE FOAM OF OPEN CELL TYPE BY RADIATION GRAFTING OF ACRYLIC ACID Kaji K;Hatada M;Yoshizawa I;Kohara C;Komai K JAPAN,ATOMIC ENERGY RESEARCH INSTITUTE; SANWA KAKO CO. 4 refs. JAPAN

Accession no.382196 Item 428 Rubber World 200,No.1,April 1989,p.51 BLACK EXPANDED POLYPROPYLENE A brief description is given of two new black grades of Arpro expanded PP from Arco Chemical they are Arpro 5313 and 5319 and are destined for use in electronics and military materials handling applications. ARCO CHEMICAL CO. USA

Accession no.379841 Item 429 Plastics in Building Construction 13,No.1,1988,p.4 POLYETHYLENE FOAM BACKER ROD FOR PAVEMENT AND HIGHWAY JOINT SEALANT BACKUP Two types of PE foam backer rod, available from Applied Extrusion Technologies, are briefly described. Type HBR XL is for concrete pavements and type HBR is for highway use. The use of a backer rod in the joint, below the surface, limits the depth of sealant placed on top of it, helps prevent excessive sealant use and prolongs sealant service life. APPLIED EXTRUSION TECHNOLOGIES INC. USA

Accession no.378414 Item 430 Plastics in Building Construction 13,No.6,1989,p.3-7 EPS BASIS FOR STRUCTURAL SYSTEM The availability of an expanded PS sandwich panel construction for structural floor and roof elements in the USA, under licence from Plastedil SA, is announced. Details of the Plastbau System are outlined and the strength and energy saving features are noted. Diagrams showing installation methods are also included. INVESTMENT HOLDINGS GROUP LTD.; PLASTEDIL SA

Item 431 Plastics in Building Construction 13,No.1,1988,p.4 POLYETHYLENE OUTER PIPE AND POLYURETHANE FOAM PROTECT STEEL HOT STEAM PIPE IN MOSCOW DIRECT HEATING SYSTEM Four complete extrusion lines for the manufacture of PE pipes are described which are to be supplied by Battenfeld for Moscow’s district heating system. The heating system utilises freely layable steel pipes the conveying the superheated steam, the steel pipes being protected and insulated by means of the PE pipes. The cavity is filled with an insulating layer of PU foam. BATTENFELD EXTRUSIONSTECHNIK GMBH USSR; WEST GERMANY

Accession no.378283 Item 432 Cellular Polymers 7,No.4,1988,p.297-308 ETHYLENE HOMO- AND COPOLYMER FOAMS Eaves D E BXL PLASTICS LTD. The production and properties of ethylene homo- and copolymer foams with densities less than 50 kg/cu.m. are reviewed. A brief historical summary is given, followed by a discussion of six key parameters as they relate to the properties and form of the foam. The diversity of the manufacturing processes available for foam production is illustrated by three distinct operating techniques. Stressstrain curves are used to demonstrate the wide spectrum of properties obtainable and examples of applications are given. 11 refs. UK

Accession no.375768 Item 433 International Polymer Science and Technology 14,No.8,1987,p.T/63-5 SOLUBILITY OF GASES IN A POLYETHYLENE MELT AND ITS IMPORTANCE FOR THE PREPARATION OF PLASTICS FOAMS BY A PHYSICAL METHOD Kolmacka J;Smilek P;Hanak J GOTTWALDOV,RESEARCH INST.FOR RUBBER & PLASTICS 1 ref. (Full translation of Plasty a Kaucuk,24,No.3,1987, p.65) CZECHOSLOVAKIA

Accession no.373916

USA

Accession no.378362

© Copyright 2004 Rapra Technology Limited

113

References and Abstracts

Item 434 International Polymer Science and Technology 14,No.8,1987,p.T/89 USE OF PE FOAM AS A HEAT- AND MOISTUREINSULATING ENVELOPE FOR A HEATCONDUCTIVE SYSTEM (SUCH AS HOT-WATER PIPES) Kudryashov V P;Kulikov Yu A;Dubyaga E G; Mikheeva N P 1 ref. (Full translation of Plast.Massy,No.3,1987,p.59A) USSR

Accession no.373606 Item 435 International Polymer Science and Technology 14,No.8,1987,p.T/88 INFLUENCE OF THE TYPE OF PHYSICAL BLOWING AGENT ON THE PROCESS OF FOAM FORMATION FROM PE MELT Kudryashov V P;Kulikov Yu A;Pavlov Yu N; Mikheeva N P;Andreevskaya L V 1 ref. (Full translation of Plast.Massy,No.3,1987,p.58) USSR

Accession no.373451

abstract includes all the information contained in the original article. BXL PLASTICS LTD.; DUNLOP SLAZENGER INTERNATIONAL LTD. UK

Accession no.368684 Item 438 Kunststoffe 78,No.3,March 1988,p.237-41 German TECHNOLOGY FOR A FLEXIBLE LIGHTWEIGHT MASS-PRODUCIBLE CAR FRONT END Rodewald H L;Pauly A IAV INGENIEURGES.FUER AGGR.& VERKEHRS.MBH The passive protection of pedestrians from car front ends can be considerably improved, compared with present day conventional constructions, by the use of a PE foam core with a PU self-skinning foam jacket for this car component. The values achievable with such a flexible front end as well as the effects on a dummy representing a pedestrian are investigated for an impact speed of 45 km/h. 3 refs. WEST GERMANY

Item 436 Plastics and Rubber Weekly No.1266,17th Dec.1988,p.6 RUMPELSTILTSKIN (TEXAS STYLE) Dempster D PE foams containing gold particles which can be moulded or machined into shapes are being developed for applications where atomic particle reflectance or absorption is needed. Uses in neutron radiation environments and in ion implantation technology are envisaged. Uses may also develop from the high electrical conductivity of gold. TEXAS A & M UNIVERSITY USA

Accession no.370202

Accession no.366507 Item 439 Plaste und Kautschuk 35,No.2,Feb.1988,p.69-70 German THERMAL STABILITY OF THIN-WALLED INTEGRAL FOAM PRODUCTS Ivanov G;Gateva M;Colakova N;Sulamski K SOFIA,RESEARCH CENTER FOR CONSTRUCTION POLYMERS A study was made of the effect of density of injection moulded, thin-walled, integral foam products made of propylene copolymers, containing 20% PE, on their lowtemperature properties. Results are discussed and evaluated. 5 refs. BULGARIA

Item 437 Plastics and Rubber Weekly No.1260,5th Nov.1988,p.13 PE FOAMS CUT GOALIE DISCOMFORT Dunlop Slazenger’s ‘High Profile’ kickers for hockey goalkeepers are made from three different grades of BXL Plastics’ closed cell foam. The inner, comfort layer is of Evazote ethylene copolymer foam; the middle layer is of Plastazote closed-cell PE foam for energy absorption; and the outer layer is of a denser Plastazote foam for strength and durability. The kickers, which fit over conventional hockey boots, are said to be the lightest available and were used by the British Olympic hockey team. This

114

Accession no.364819 Item 440 ANTEC 88.Proceedings of the 46th Annual Technical Conference. Atlanta,18-21 April 1988,p.719-22. 012 PRODUCTION OF MICROCELLULAR FOAMS IN SEMICRYSTALLINE THERMOPLASTICS Colton J GEORGIA INSTITUTE OF TECHNOLOGY (SPE) Difficulties in producing microcellular foams from semicrystalline polymers are discussed and nucleation

© Copyright 2004 Rapra Technology Limited

References and Abstracts

theory is considered. It is shown that microcellular foams can be produced from PP (a semicrystalline polymer) by processing above its m.p. (thereby producing an amorphous material) and adding appropriate nucleating agents. The nucleation theory is found to predict quite well the number of cells produced and the effects of processing parameters. Production of microcellular foams from semicrystalline polymers is shown to require accurate temp. control to assure that the nucleated cells will not grow too large or too quickly. 15 refs. USA

Accession no.363915

EXTRUSION OF ARTICLES FROM FOAMED THERMOPLASTICS Nikolaeva N E;Sabsai O Yu;Malkin A Ya;Fridman M L 11 refs. Full translation of Plast.Massy,No.7,1985,p.33. USSR

Accession no.359719 Item 444 Plastics and Rubber International 13,No.3,June 1988,p.3 BXL LAUNCHES NEW PE FOAMS FOR ELECTRONICS

Item 441 ANTEC 88.Proceedings of the 46th Annual Technical Conference. Atlanta,18-21 April 1988,p.733-7. 012 STRUCTURE-PROPERTY RELATIONSHIP AND ITS CORRELATION WITH THERMAL BEHAVIOUR OF CROSSLINKED EXPANDED EVA FORMULATION Hadjiandreou P;Zitouni F ALGERIAN INSTITUTE OF PETROLEUM (SPE)

BXL Plastics’ ERP Division is to introduce new grades of antistatic and conductive closed-cell crosslinked PE and ethylene copolymer foam at the Internepcon Exhibition to meet a growing demand from the electronics industry, for ways of minimising the effect of static electricity on circuits embodying static-sensitive devices, particularly using metal oxide/silicone technology. Very brief details are noted of Evazote C conductive closedcell, crosslinked ethylene-vinyl acetate copolymer foam. BXL PLASTICS LTD.,ERP DIV.

Using TGA, a correlation was established between the rates of crosslinking and decomposition of azodicarbonamide blowing agent in expanded EVA preparation. The relationship between processing conditions, properties and structure of cured EVA foams was also examined. 11 refs.

Accession no.357352

ALGERIA

Accession no.363897 Item 442 Plastics Engineering 44,No.8,Aug.1988,p.53-5 MAKING MICROCELLULAR FOAMS FROM CRYSTALLINE POLYMERS Colton J S GEORGIA INSTITUTE OF TECHNOLOGY Microcellular foams are reported to offer superior mechanical properties, while retaining the insulation properties of conventional foams. Low gas solubility resulting from the rigidity of the crystal lattice has precluded their production in semi-crystalline polymers, but a new process is said to have been experimentally proven in PP. Aspects covered include production difficulties, experimental details, results and conclusions. USA

Accession no.360550

UK

Item 445 Plastics World 46,No.7,July 1988,p.62-5 TAKE-OUT FOOD: THE APPETITE FOR PLASTICS GROWS Lodge C Changing lifestyles are reported to have created a 1.2 billion US dollars/wk. market for take-away foods, that is growing at 18%/yr. The demand for proven take-away food packaging, specifically oriented PS sheet and PS foam, and crystallised PETP sheet, is continuing to grow at a high rate. Although plastic is the dominant and fastestgrowing packaging material in the take-away food business, it use is threatened by a variety of pending legislation. Details are given of products available from Amoco Foam Products, Amoco Chemical, Fina Oil & Chemical, General Electric Plastics, Mobil Chemical and Himont USA. AMOCO CHEMICALS CORP.; AMOCO FOAM PRODUCTS CO.; FINA OIL & CHEMICAL; GENERAL ELECTRIC PLASTICS; HIMONT USA INC.; MOBIL CHEMICAL CO. USA

Accession no.357280

Item 443 International Polymer Science and Technology 12,No.12,1985,p.T51-3 RHEOLOGICAL CHARACTERISTICS OF THE

© Copyright 2004 Rapra Technology Limited

115

References and Abstracts

Item 446 Plastics Industry News (Japan) 34,No.5,May 1988,p.67 HEAT RESISTANT PP SHEET Furukawa Electric has commenced marketing a lightweight heat insulating PP low foamed sheeting. It is prepared by extrusion, and foaming 2-4 times by an inert gas blowing agent. It can be used in temps of 120C, with no resultant effects; it has a high mechanical strength. Sheet thickness is controlled in the range 1-6mm; maximum width is 1350mm. Food packaged by this film may be heated in its package inside an electronic heater, and served immediately. This abstract includes all the information contained in the original article. FURUKAWA ELECTRIC CO.LTD. JAPAN

Accession no.356580 Item 447 Modern Plastics International 18,No.6,June 1988,p.43-4 POLYOLEFIN FOAMS ARE SET TO TAKE ON MORE PERFORMANCE JOBS Mapleston P Recent trends in new types of polyolefin foams are highlighted. New grades include Alveolit TP PP foam sheet from Alveo, Eperan PP expandable foam bead from Kaneka for automotive applications, a physically crosslinked PE foam with a thermoplastic elastomer coating (Volex), Opcel open-cell PE foam from Alveo for sound insulation and electrical applications, Evazote C conductive crosslinked EVA foam from BXL, Plastazote AS antistatic PE foam for cushion packaging and Dyna-No-Motion PE foam for medical applications. ALVEO AG; BXL PLASTICS LTD.; KANEKAGAFUCHI CHEMICAL INDUSTRY CO.LTD. USA

Accession no.356440 Item 448 Plastics Industry News (Japan) 34,No.4,April 1988,p.51 PE THIN SHEETING Brief details are presented on a PE multiporous thin sheeting of open cell foam structure. Planned production of the sheeting by Asahi Chemical and its application in refrigerators for water adsorption use is outlined. ASAHI CHEMICAL CO.LTD.

Item 449 Kunststoffe 77,No.9,Sept.1987,p.860-3 German INJECTION MOULDED STRUCTURAL FOAM MADE FROM POLYPROPYLENE Hell J;Nezbedova E;Ponesicky J PRAGUE,MATERIALS RESEARCH INSTITUTE The method of structural foam moulding permits the manufacture of foams with a compact skin and a cellular core. The properties of such mouldings depend, among other parameters, on the structure of the foam. This article reports on a study of the influence of density, specimen thickness, orientation and ambient temp. on mechanical properties and chemical resistance of injection moulded structural foams made from PP. Results are discussed with reference to relationships between structure and properties. 5 refs. CZECHOSLOVAKIA

Accession no.353200 Item 450 Plastics and Rubber Weekly No.1226,27th Feb.1988,p.8 ANTISTATIC AND CONDUCTIVE FOAMS FROM BXL PLASTICS BXL Plastics’ ERP division is introducing two new grades of antistatic and conductive foams at this years Internepcon exhibition at the Birmingham NEC in the UK in March 1988. Brief details are given on conductive closed-cell crosslinked EVA copolymer foam, Evazote C, and antistatic PE foam Plastazote AS, both used for electronics packaging. BXL PLASTICS LTD.,ERP DIV. UK

Accession no.353077 Item 451 Plastics News (Australia) Oct.1987,p.30 CROSSLINKED LOW DENSITY PE AND EVA FOAMS Webster D MICROCELL TECHNOLOGY CONSULTANTS LTD.

JAPAN

Brief details are given of the use of LDPE and EVA foams in automotive and leisure applications. Examples mentioned are car boot mats and interior mats, vehicle trim, headlamp gaskets, and vibration absorbers, gym mats, luggage, boat hull cladding, sports wear and buoyancy aids.

Accession no.356374

AUSTRALIA

Accession no.350861

116

© Copyright 2004 Rapra Technology Limited

References and Abstracts

Item 452 Plastics and Rubber Weekly No.1217,12th Dec.1987,p.10/7 TRAINERS: GETTING DOWN TO BASICS - AND FASHION A review is presented of recent developments in sports shoes; today’s trainers, which come in all colours and shapes, with multilayer, multicolour soles for comfort and aesthetic appeal, replace the former black canvas plimsoll with rubber sole. Shoes are now designed specifically with each sport in mind, although they have essentially the same basic design with variations in the composition of the sole. WORLD

Accession no.349895 Item 453 Plastics Industry News (Japan) 33,No.9,Sept/Oct.1987,p.130 FOAM PE BOARD Sekisui Kaseihin Kogy Co. has started production of closed cell type PE foam board. The PE board has a low density cushion effect and high heat insulation. Boards will be produced with thicknesses of 40, 50 and 60mm in 1 metre widths for packaging, shock absorption and moisture barrier uses. The company is already producing PS and PU foamed materials. This abstract includes all the information contained in the original article. SEKISUI KASEIHIN KOGYO KK

reduces the risks of erosion, scour and the formation of free spans, slows the movement of sediment so that protective build up occurs around pipe and provides stable beach and riser area runs. It is also effective as a fast infill for free spans or around fixed installations and for the stabilisation of dunes, sand bars and estuary or harbour areas. CEBO (UK) LTD. UK

Accession no.343320 Item 456 Mechanics of Cellular Plastics. ed.by N.C.Hilyard Barking,Applied Science Publishers Ltd.,1982, p.263322. R.ROOM. 6124 STRUCTURAL FOAMS Throne J L Thermoplastic structural foams with bulk densities not less than 50% of the solid resin densities are considered. Cellular morphology, uniform-density cell behaviour, the I-beam concept in designing, core-density profile and the role of the skin, mechanical properties, and ductile-brittle transitions are discussed. 63 refs. Accession no.207102

JAPAN

Accession no.346450 Item 454 Plastics Technology 33,No.11,Oct.1987,p.23 CLEAR PP SHEET FOR BLISTER PACKS Very brief details are noted of Exxon Chemicals’ new, low-cost PP sheet for pharmaceutical thermofilm fill-andseal blister packaging, designated Extrel XPP 603. It is said to provide excellent clarity, gloss and moisture barrier; at 10mm thickness, the sheet is said to provide a moisture barrier equivalent to a 10mm PVC film with a 40gm PVDC coating. EXXON CHEMICAL CO. USA

Accession no.344813 Item 455 Oilman May 1987,p.42 PLASTIC SEAWEED PROVES ITS WORTH Cebo UK supply a closed-cell foamed PP seaweed, called Cegrass, which is designed to protect pipeline installations and other subsea equipment. The artificial seaweed

© Copyright 2004 Rapra Technology Limited

117

References and Abstracts

118

© Copyright 2004 Rapra Technology Limited

Subject Index

Subject Index A ABRASION RESISTANCE, 62 83 141 175 179 208 ABS, 111 296 456 ABSORPTION, 185 235 315 436 ACCELERATED AGEING, 299 375 ACCELERATED TEST, 299 375 ACCELERATOR, 136 168 169 293 ACCELEROMETRY, 297 ACCUMULATOR, 269 ACCUMULATOR HEAD, 312 ACETONITRILE, 310 ACOUSTIC INSULATION, 30 160 165 181 182 248 311 351 376 422 447 ACOUSTIC PROPERTIES, 182 ACRYLIC ACID, 240 ACRYLIC ACID COPOLYMER, 427 ACRYLIC POLYMER, 325 ACRYLIC RESIN, 325 ACRYLONITRILE COPOLYMER, 340 ACTIVATED CARBON, 389 ACTIVATION ENERGY, 243 259 316 ACTIVATOR, 86 117 130 169 ADDITION POLYMERISATION, 246 ADHESION, 97 103 104 188 192 195 196 208 246 248 262 296 297 395 ADHESION PROMOTION, 104 262 296 ADHESIVE, 4 37 80 101 196 246 248 296 375 403 ADHESIVE TAPE, 158 196 237 403 425 AEROSPACE APPLICATION, 309 AGEING, 85 147 228 271 294 297 299 303 342 375 AGEING RESISTANCE, 347 AGRICULTURAL APPLICATION, 303 AIBN, 418 AIR CIRCULATION, 41 AIR COOLING, 271 273 AIR DIFFUSION, 262 AIR DUCT, 420 422 AIR ENTRAPMENT, 410 AIR FLOW, 37 345 422 AIRBAG, 22 ALKALI METAL, 103

ALKANE, 202 255 ALKENYL, 133 ALKOXYSILANE, 146 ALKYL HYDROXIDE, 271 ALKYLAMINE, 371 ALLYLAMINE, 372 ALPHA-OLEFIN COPOLYMER, 197 ALPHA-OLEFIN TERPOLYMER, 197 ALUMINIUM, 316 385 419 ALUMINIUM SILICATE, 43 50 55 AMMONIUM HALIDE, 293 ANISOTROPY, 38 57 153 174 406 ANNULAR DIE, 311 ANTIOXIDANT, 385 ANTI-SLIP PROPERTIES, 208 ANTISTATIC PROPERTIES, 91 302 426 427 444 447 450 APPEARANCE, 124 186 241 293 AQUEOUS DISPERSION, 103 ARGON, 185 233 235 321 339 433 ARRHENIUS FACTOR, 243 ARTIFICIAL HIP, 52 ARTIFICIAL KNEE, 52 ARTIFICIAL SEAWEED, 455 ASPECT RATIO, 314 419 ATOMIC FORCE MICROSCOPY, 149 ATTENUATED TOTAL REFLECTANCE SPECTROSCOPY, 149 AUTOCLAVE, 21 25 69 92 163 224 AUTOMOTIVE APPLICATION, 3 9 22 30 38 58 64 72 91 92 98 102 111 163 164 165 168 173 177 195 196 216 221 230 237 248 249 250 260 279 292 297 301 303 311 312 317 324 331 351 368 376 379 386 388 397 398 410 413 414 420 422 424 447 451 AZOBISFORMAMIDE, 14 18 40 51 53 86 107 117 118 135 157 218 234 248 253 269 277 AZOBISISOBUTYRONITRILE, 418 AZOCARBONAMIDE, 219 AZODICARBONAMIDE, 14 18 40 51 53 86 107 117 118 135 157 203 218 234 248 253 269 277 303 385 441

© Copyright 2004 Rapra Technology Limited

AZODICARBONIC ACID DIAMIDE, 169 228

B BACTERICIDE, 239 BANDAGE, 150 BARREL TEMPERATURE, 127 365 BARRIER LAYER, 101 244 BARRIER PACKAGING, 80 85 101 BARRIER PROPERTIES, 85 101 272 365 BARRIER RESIN, 101 BATCH PROCESSING, 215 303 BATTERY CASE, 164 406 BEADED POLYMER, 303 BEADS, 37 41 92 96 125 161 167 249 254 301 302 336 346 349 350 366 369 386 398 413 BENZENE, 316 BENZENE SULFONYL HYDRAZIDE, 385 BENZISOTHIAZOLINONE, 239 BIAXIAL ORIENTATION, 59 193 356 BICARBONATE, 105 135 BICYCLE, 167 BINARY BLEND, 5 BINARY SYSTEM, 134 BIREFRINGENCE, 218 BLENDING, 11 28 368 BLISTER PACKAGING, 454 BLOCK COPOLYMER, 31 101 107 178 252 368 BLOW EXTRUSION, 19 74 79 BLOW MOULDING, 34 35 95 140 193 263 312 420 BLOW MOULDING MACHINE, 422 BLOWN FILM, 69 70 281 356 BOND STRENGTH, 296 BONDING, 102 188 248 262 296 309 318 425 BONDING AGENT, 246 248 296 375 BONE REGENERATION, 52 BORON NITRIDE, 201 298 BOUNDARY CONDITION, 299 314 345 359 BRANCHED CHAIN, 81 273 BRANCHING, 36 42 48 68 69 75 78 241 249 257 287 433

119

Subject Index

BREAKING STRAIN, 40 BREAKING STRESS, 168 BRITTLENESS, 101 311 456 BUBBLE FORMATION, 6 23 88 117 268 269 303 402 BUBBLE GROWTH, 23 25 81 117 BUBBLE STABILITY, 303 BUCKLING, 303 400 BUILDING APPLICATIONS, 92 158 165 239 272 299 303 309 375 404 405 430 BUILDING BLOCK, 239 BULK DENSITY, 247 345 456 BUMPER, 91 161 279 302 317 366 368 386 398 413 414 424 438 BUOYANCY AID, 348 BUTADIENE-ACRYLONITRILE COPOLYMER, 40 196 BUTADIENE-STYRENE COPOLYMER, 196 BUTANE, 31 42 78 245 265 335 342 347 BUTENE, 81 BUTENE COPOLYMER, 183 BUTYL RUBBER, 248 BUTYLENE, 81 BUTYLENE COPOLYMER, 183

C CABLE INSULATION, 127 271 365 378 385 CALCIUM CARBONATE, 2 43 128 246 CALENDER, 144 194 CALIBRATION, 94 377 CAPILLARY DIE, 172 CAPILLARY FLOW, 443 CAPILLARY RHEOMETRY, 252 CAR MAT, 451 CARBON, 316 CARBON BLACK, 40 151 416 CARBON DIOXIDE, 12 17 19 21 25 75 92 123 138 139 171 185 194 204 207 215 222 233 235 262 273 275 276 280 294 306 315 316 321 332 339 342 347 365 407 433 435 CARBON MONOXIDE, 316 CARBOXYL GROUP, 334 CARBOXYLIC ACID, 334 CAST FILM, 80 CASTING, 287 316 CATALYSIS, 175 CATALYST, 5 7 31 92 93 107 114 154 196 223 224 232 241 249 292 385 CATALYTIC DEGRADATION,

120

385 CATAPHORESIS, 248 CAVITATION, 169 CELL COLLAPSE, 101 194 246 303 316 339 345 CELL COUNT, 123 344 CELL DENSITY, 19 21 26 42 48 50 53 74 75 78 79 105 123 128 157 172 204 207 244 273 275 284 314 315 CELL GROWTH, 80 101 117 168 169 194 198 273 275 303 314 315 CELL MORPHOLOGY, 12 18 19 54 74 79 101 CELL NUCLEATION, 19 CELL NUMBER, 159 194 314 341 CELL OPENING, 92 262 CELL SIZE, 14 18 19 21 34 39 42 50 53 57 65 74 75 79 101 116 117 125 128 139 168 169 182 194 204 241 246 247 259 270 273 289 303 314 315 345 380 419 440 CELL SIZE DISTRIBUTION, 314 CELL STRUCTURE, 2 14 16 17 18 19 21 29 34 57 63 74 75 78 81 84 85 101 117 123 135 142 151 168 169 172 174 194 203 207 213 246 248 259 262 273 275 303 308 314 315 332 334 359 380 384 385 400 419 CELLULAR, 53 111 271 CELLULAR CORE, 111 CELLULAR MATERIALS, 426 CFC, 299 303 344 345 359 402 411 414 CFC FREE, 175 182 302 375 CFC REPLACEMENT, 262 296 299 303 345 352 CFC-11, 299 CFC-114, 344 CFC-12, 344 359 CHAIN BRANCHING, 173 273 CHARACTERISATION, 14 34 36 48 69 76 77 78 79 83 116 191 210 215 222 227 268 270 306 310 326 CHARPY, 271 CHEMICAL BLOWING AGENT, 34 54 79 80 85 92 105 118 119 169 194 263 303 CHEMICAL COMPOSITION, 189 190 CHEMICAL CROSSLINKING, 92 CHEMICAL ETCHING, 86 CHEMICAL MODIFICATION, 28 86 136

CHEMICAL PROPERTIES, 194 279 CHEMICAL RECYCLING, 246 CHEMICAL RESISTANCE, 165 194 279 297 381 405 449 CHEMICAL SHIFT, 101 CHEMICAL STRUCTURE, 49 72 81 107 140 193 216 228 249 258 259 273 CHLORINATION, 293 CHLOROFLUOROCARBON, 299 303 344 345 359 402 411 414 CHLOROFLUOROHYDROCARBON, 92 262 CHLOROFORM, 88 CHLORONAPHTHALENE, 416 CHROMATOGRAPHY, 136 CITRIC ACID, 75 101 105 135 142 303 CIVIL ENGINEERING, 429 455 CLADDING, 272 CLAMP FORCE, 62 73 CLAMPING UNIT, 56 CLARITY, 312 454 CLAY, 21 CLOSED LOOP CONTROL, 144 194 CLOSURE, 237 CLOTHING, 41 362 CLOTHING APPLICATION, 277 COACTIVATOR, 86 COALESCENCE, 15 42 81 198 204 273 COATHANGER DIE, 144 194 COATING, 4 37 141 212 318 379 395 447 COEFFICIENT OF EXPANSION, 81 271 COEXTRUSION, 80 101 144 194 244 260 296 311 312 COHESIVE STRENGTH, 296 COLD FEED, 14 COLOUR, 62 73 85 293 299 360 COLOUR CHANGING, 62 73 COMBUSTION PRODUCT, 374 COMMERCIAL INFORMATION, 91 98 111 144 161 163 366 397 422 426 COMPACTION, 318 COMPATIBILISATION, 28 121 COMPATIBILISER, 79 92 121 205 281 296 COMPLEX FORMATION, 385 COMPOSITE, 10 12 21 24 40 55 87 89 94 126 141 165 187 188 195 212 246 263 264 312 322 334 364 368 COMPOSITIONAL

© Copyright 2004 Rapra Technology Limited

Subject Index

DISTRIBUTION, 9 COMPOUNDING, 14 15 37 40 74 145 152 168 169 292 COMPRESSED AIR, 194 271 COMPRESSION, 14 38 40 83 85 94 166 167 213 243 245 259 266 380 400 419 COMPRESSION MODULUS, 1 43 99 192 243 246 COMPRESSION MOULD, 303 315 COMPRESSION MOULDING, 52 57 225 304 306 308 373 441 COMPRESSION PROPERTIES, 4 16 30 33 43 60 71 72 83 84 90 153 154 165 223 246 249 254 262 270 279 286 291 317 363 380 400 412 414 419 COMPRESSION SET, 9 30 33 76 83 113 148 154 166 168 261 279 291 317 412 COMPRESSION STRENGTH, 84 165 246 249 262 279 297 303 317 COMPUTER AIDED ANALYSIS, 299 COMPUTER AIDED DESIGN, 322 COMPUTER AIDED TESTING, 339 COMPUTER CONTROL, 62 111 COMPUTER MODEL, 85 COMPUTER PROGRAM, 145 206 299 COMPUTER SIMULATION, 67 85 COMPUTERISED ANALYSIS, 145 CONCRETE, 115 158 429 CONDUCTIVE MATERIALS, 261 450 CONDUCTIVE PLASTIC, 444 447 CONDUCTOR, 385 CONSTRAINED GEOMETRY, 175 CONSTRAINED GEOMETRY CATALYST, 154 CONTACT ANGLE, 262 CONTACT MOULDING, 246 CONTINUOUS EXTRUSION, 314 CONTINUOUS MOULDING, 312 CONTINUOUS VULCANISATION, 9 CONTINUUM MECHANICS, 40 CONTROL EQUIPMENT, 312 365 CONTROL SYSTEM, 62 85 111 CONTROLLABILITY, 156

CONTROLLED ATMOSPHERE, 404 COOLING, 62 73 85 88 108 144 152 194 199 204 205 229 271 273 304 308 311 314 315 326 365 COOLING RATE, 271 273 315 COOLING TIME, 62 73 COPOLYETHER, 107 COPOLYMER, 180 197 279 COPOLYMER COMPOSITION, 8 103 136 239 COPOLYMERISATION, 114 180 COPPER, 385 CORRELATION COEFFICIENT, 168 CORROSION, 141 248 261 CORRUGATED SHEET, 409 COSTS, 22 62 73 98 175 181 302 317 338 365 409 410 COUNTER-PRESSURE, 62 73 194 269 COUNTER-ROTATING EXTRUDER, 123 314 344 359 COUPLING AGENT, 10 74 COVALENT BONDING, 262 CRACK RESISTANCE, 305 CRACKING, 296 368 385 CRASH, 297 CRASH RESISTANCE, 38 297 CRASH SIMULATOR, 297 412 CRASHPAD, 412 CREEP, 33 82 89 90 154 238 246 254 266 303 383 394 CREEP RECOVERY, 178 CREEP RESISTANCE, 184 CRITICAL SHEAR RATE, 319 333 CROSS BEAM, 195 CROSS HEAD DIE, 365 CROSS-POLARISATION, 101 315 CROSSLINK DENSITY, 66 168 169 262 CROSSLINKED, 29 36 39 62 66 73 92 120 145 151 174 175 178 179 184 206 210 212 241 261 268 306 308 319 333 405 441 CROSSLINKED COPOLYMER, 76 196 CROSSLINKED POLYMER, 165 196 228 232 319 333 CROSSLINKING, 7 8 17 25 36 44 62 65 76 84 92 100 113 146 148 149 155 157 163 168 169 196 200 206 216 219 221 223 224 225 237 253 258 262 267 293 300 303 319 333 343 355 360 367 393 395 397 418 419 447

© Copyright 2004 Rapra Technology Limited

CROSSLINKING AGENT, 49 117 351 CROSSLINKING RATE, 169 CRYSTAL GROWTH, 85 CRYSTAL STRUCTURE, 315 CRYSTAL TRANSITION, 339 CRYSTALLINITY, 12 69 77 78 79 80 85 101 114 121 130 215 219 237 246 249 252 259 260 308 315 339 381 416 419 445 CRYSTALLISATION, 26 44 71 85 134 145 215 245 315 339 387 416 CRYSTALLISATION RATE, 77 CRYSTALLISATION TEMPERATURE, 78 79 100 315 339 CRYSTALLITE, 315 CURE RATE, 168 169 441 CURE TEMPERATURE, 9 168 293 296 CURE TIME, 9 62 73 83 141 293 296 CURING, 9 14 16 62 73 146 153 184 224 248 285 296 303 CURING AGENT, 7 8 16 49 65 100 117 136 146 148 168 169 248 258 293 303 304 CURING SYSTEM, 168 CUSHIONING, 43 139 162 175 181 197 211 261 289 302 303 325 331 379 382 392 405 411 412 415 426 452 CYANURIC ACID, 385 CYCLIC LOADING, 166 CYCLING, 297

D DAMPING, 89 175 180 181 195 248 412 415 DART DROP, 368 DASHBOARD, 195 DATA COLLECTION, 111 DATA MANAGEMENT, 111 DATA TRANSMISSION, 378 DECALIN, 416 DECOMPOSITION, 15 95 168 169 212 271 303 306 441 DECOMPOSITION PRODUCT, 316 DECOMPOSITION RATE, 169 DECOMPOSITION TEMPERATURE, 14 169 364 DECOMPRESSION, 88 DEFECTS, 73 DEFLECTION TEMPERATURE, 273

121

Subject Index

DEFORMATION, 37 38 43 88 89 132 213 266 291 295 303 317 368 383 394 400 412 419 DEFORMATION TEMPERATURE, 165 194 DEGASSING, 236 DEGRADATION, 85 147 228 271 306 375 377 385 441 DEGRADATION PRODUCT, 316 385 DEGRADATION RATE, 316 385 DEGRADATION TEMPERATURE, 316 DEGREE OF BRANCHING, 36 DEGREE OF CROSSLINKING, 36 76 206 225 DEGREE OF CRYSTALLINITY, 85 259 315 DEGREE OF FOAMING, 62 73 435 DEGREE OF POLYMERISATION, 307 316 334 339 DEGREE OF UNSATURATION, 9 DELAMINATION, 104 296 DEMOULD, 296 DENSITY DISTRIBUTION, 262 DEPOLYMERISATION, 316 DESIGN, 22 56 98 166 181 295 378 415 426 452 DESIGN OF EXPERIMENTS, 38 54 DESORPTION, 171 315 DEVOLATILISATION, 240 344 DI-2-ETHYLHEXYL PHTHALATE, 208 DIACRYLATE, 361 DIALKYL PEROXIDE, 248 DIALLYL PHTHALATE, 49 DIAZO COMPOUND, 360 DIBENZYLIDENE SORBITOL, 101 DICHLORODIFLUOROMETHANE, 359 DICHLOROFLUOROMETHANE, 359 DICUMYL PEROXIDE, 8 49 65 100 117 219 258 DIE, 3 6 25 26 144 194 260 273 280 312 314 344 356 359 387 DIE CUTTING, 242 DIE DESIGN, 193 276 287 DIE GAP, 75 344 DIE HEAD, 312 DIE PRESSURE, 276 339 344 DIE SWELL, 252 DIE TEMPERATURE, 19 105 127 359

122

DIELECTRIC PROPERTIES, 46 201 298 378 DIENE, 395 DIENE TERPOLYMER, 197 DIFFERENTIAL SCANNING CALORIMETRY, 5 12 32 44 57 87 90 101 107 132 135 143 145 151 152 153 160 188 206 210 211 215 218 219 227 253 258 259 270 278 281 315 316 393 416 DIFFUSION, 81 88 90 169 171 236 254 262 303 314 315 339 345 359 380 385 404 DIFFUSION COEFFICIENT, 314 345 380 DIFFUSION RATE, 262 345 DIFFUSIVITY, 215 266 315 345 DIFLUOROETHANE, 327 335 DIHYDRAZIDE, 385 DIHYDRIC ALCOHOL, 361 DIIODOMETHYL TOLYLSULFONE, 239 DIMENSIONAL CONTROL, 62 73 DIMENSIONAL STABILITY, 77 113 147 154 177 205 246 256 262 297 314 336 346 349 357 393 421 423 DIMETHACRYLATE, 361 DIMETHYLPHENYL FLUORODICHLORO METHYLTHIOSULFAMIDE, 239 DINITROSO PENTAMETHYLENE TETRAMINE, 14 136 DIOCTYL PHTHALATE, 208 DIPHENYLMETHANE DIISOCYANATE, 262 DIRECT EXTRUSION, 80 303 DIRECT GASIFICATION, 80 DIRECT INJECTION, 260 DISPERSING AGENT, 290 DISPERSION, 103 332 344 DISPLACEMENT, 297 DISSIPATION FACTOR, 378 DISSOLUTION, 273 DIUREA, 385 DOMESTIC APPLIANCE, 92 98 111 296 331 DOMESTIC APPLICATIONS, 448 DOMESTIC EQUIPMENT, 92 98 111 448 DOSING, 16 84 144 285 365 423 DOUBLE BOND, 84 DRAW RATIO, 66 344 DRAWDOWN, 186

DRAWING, 72 DROP TEST, 320 DRY BLENDING, 142 152 176 DRYING, 74 DUAL DENSITY, 279 DUAL HARDNESS, 312 DUCTILE-BRITTLE TRANSITION, 166 DUCTILITY, 101 205 456 DURABILITY, 234 311 437 DURENE, 416 DWELL TIME, 24 168 DYNAMIC MECHANICAL ANALYSIS, 55 94 153 259 DYNAMIC MECHANICAL PROPERTIES, 36 39 55 77 82 153 178 238 259 DYNAMIC MODULUS, 99 243 DYNAMIC PROPERTIES, 36 39 55 77 82 153 178 238 259 438 DYNAMIC RHEOLOGICAL ANALYSIS, 7 DYNAMIC VISCOSITY, 212 DYNAMIC VULCANISATION, 384

E EBULLATION, 205 ECONOMIC INFORMATION, 27 91 92 98 111 161 163 324 445 EIGEN VALUE, 345 ELASTIC MODULUS, 1 40 61 100 101 206 213 225 243 368 ELASTIC PROPERTIES, 5 8 55 89 116 168 236 259 ELASTICITY, 40 53 170 226 243 318 336 346 349 ELECTRIC CABLE, 46 ELECTRIC MOTOR, 73 ELECTRICAL APPLICATIONS, 177 261 385 406 447 ELECTRICAL CABLE, 46 ELECTRICAL CAPACITY, 164 ELECTRICAL CONDUCTIVITY, 163 444 450 ELECTRICAL INSULATION, 385 ELECTRICAL MOTOR, 73 ELECTRICAL PROPERTIES, 444 ELECTRICAL RESISTIVITY, 261 427 ELECTROCHEMICAL, 164 ELECTRON BEAM COATING, 379 ELECTRON BEAM CURING, 153 393 ELECTRON BEAM IRRADIATION, 16 374

© Copyright 2004 Rapra Technology Limited

Subject Index

ELECTRON DIFFRACTION, 101 ELECTRON MICROSCOPY, 5 72 151 210 224 255 315 ELECTRON SCANNING MICROSCOPY, 5 72 151 210 224 ELECTRONIC APPLICATIONS, 91 98 177 214 302 410 428 444 450 ELECTROSTATIC PROPERTIES, 147 ELONGATION, 85 108 209 271 276 278 281 297 318 374 383 ELONGATION AT BREAK, 50 53 77 101 128 139 260 261 291 341 ELONGATIONAL FLOW, 47 ELONGATIONAL VISCOSITY, 7 18 36 66 209 289 EMBOSSING, 86 195 305 EMISSION CONTROL, 92 ENCAPSULATION, 234 END GROUP, 361 ENERGY ABSORPTION, 22 38 43 64 82 101 163 165 175 180 181 194 195 242 248 249 279 297 317 363 368 405 413 414 415 424 437 453 ENERGY CONSERVATION, 152 ENERGY CONSUMPTION, 62 73 ENERGY DISSIPATION, 41 368 412 ENERGY EFFICIENCY, 262 302 ENERGY LOSS, 168 ENGINEERING APPLICATIONS, 89 248 297 381 ENGINEERING PLASTIC, 248 297 381 ENVIRONMENTAL LEGISLATION, 92 ENVIRONMENTAL PROTECTION, 92 175 ENVIRONMENTAL STRESS CRACKING, 296 ENVIRONMENTALLY FRIENDLY, 52 EPOXIDE RESIN, 4 208 246 EQUILIBRIUM, 11 206 339 EROSION CONTROL, 455 ERROR ANALYSIS, 94 ETHANE, 202 294 ETHENE, 180 ETHENE COPOLYMER, 7 8 17 33 50 53 71 84 103 104 107 113 120 122 128 137 146 148 150 176 183 189 190 197 200 224 248 252 ETHER COPOLYMER, 107

ETHYLENE, 180 ETHYLENE ACRYLIC ACID COPOLYMER, 392 ETHYLENE BUTENE COPOLYMER, 134 ETHYLENECHLOROTRIFLUOROETHYLENE COPOLYMER, 201 298 ETHYLENE COPOLYMER, 7 8 17 33 50 53 71 84 103 104 107 113 120 122 128 137 146 148 150 176 183 189 190 197 200 224 248 252 293 300 305 332 334 337 351 371 372 427 432 439 ETHYLENE-OCTENE COPOLYMER, 5 36 43 55 117 127 ETHYLENE-PROPYLENE COPOLYMER, 96 101 103 137 153 183 303 355 368 ETHYLENE-PROPYLENE TERPOLYMER, 134 ETHYLENE-PROPYLENEDIENE TERPOLYMER, 9 11 14 40 136 168 169 196 299 341 375 384 ETHYLENE-PROPYLENENORBORNENE TERPOLYMER, 136 ETHYLENE-STYRENE COPOLYMER, 76 154 162 182 413 ETHYLENE-STYRENE INTERPOLYMER, 175 ETHYLENE-VINYL ACETATE COPOLYMER, 5 8 16 33 62 73 76 90 94 108 113 132 143 153 155 163 178 179 208 234 237 238 239 246 261 266 267 285 303 304 308 317 383 394 441 444 447 450 451 452 ETHYLENE-VINYL ALCOHOL COPOLYMER, 80 101 244 340 ETHYLIDENE NORBORNENE COPOLYMER, 136 ETHYLIDENE NORBORNENE TERPOLYMER, 169 EXPANSION, 39 54 62 73 81 83 134 149 155 168 169 174 178 204 206 210 238 248 256 271 279 290 301 303 314 317 334 342 359 366 378 394 404 428 EXPANSION COEFFICIENT, 81 210 271 293 332 EXPANSION JOINT, 429 EXPANSION MOULDING, 102 EXPANSION RATIO, 8 15 42 48

© Copyright 2004 Rapra Technology Limited

78 100 103 110 124 125 139 148 157 165 264 EXPERIMENTAL DESIGN, 22 EXPLOSIVE DECOMPRESSION, 169 EXTENDER, 169 EXTENSION, 40 EXTENSIONAL FLOW, 257 401 402 EXTENSIONAL STRESS, 281 EXTENSIONAL VISCOSITY, 47 281 401 EXTRUDATE, 14 185 235 EXTRUDER, 14 19 48 62 68 69 73 74 85 95 106 123 142 144 170 172 194 208 217 233 240 260 271 273 275 276 280 314 344 359 365 402 431 EXTRUDER HEAD, 271 EXTRUSION BLOW MOULDING, 95 193 312 EXTRUSION BLOWING, 19 74 79 271 EXTRUSION COATING, 257 277 EXTRUSION COMPOUNDING, 74 EXTRUSION RATE, 9 129

F FABRIC, 58 277 FAILURE, 246 271 296 385 FALLING WEIGHT, 153 400 FANCY GOODS, 234 FASTENING, 248 FATIGUE, 166 368 456 FATTY ACID, 359 FATTY ACID AMIDE, 371 372 FATTY ACID ESTER, 278 371 372 FEED-BLOCK, 144 194 FEED ZONE, 194 FEEDER, 73 194 FEEDING, 73 194 271 FEEDSTOCK, 27 FERROUS AMMONIUM SULFATE, 427 FIBRE, 134 165 FIBRE CONTENT, 246 368 FIBRE GLASS, 221 FIBRE ORIENTATION, 368 FIBRE-REINFORCED PLASTIC, 24 74 FIBRIL, 165 FICK’S SECOND LAW, 345 380 FILL FACTOR, 169 FILLERS, 2 10 11 21 43 50 53 74 101 128 139 151 207 246 305

123

Subject Index

323 341 385 421 FILMS, 5 59 80 109 158 193 216 257 276 277 278 281 307 311 313 356 368 377 385 443 FILTRATION, 389 FINISHING, 92 FINITE DIFFERENCE ANALYSIS, 359 FINITE ELEMENT ANALYSIS, 67 85 167 217 322 FIRE PROTECTION, 165 FIRE RESISTANCE, 403 FLAME PROOFING, 92 FLAME RESISTANCE, 305 376 FLAME RETARDANT, 92 374 376 379 389 426 FLAME TREATMENT, 262 FLAMMABILITY, 195 297 305 345 374 376 379 403 FLAT DIE, 194 260 FLAW, 50 128 FLEXIBILITY, 58 92 120 139 146 183 189 190 242 293 300 338 389 438 FLEXURAL MODULUS, 30 63 246 273 303 FLEXURAL PROPERTIES, 4 13 30 34 63 77 85 160 177 194 214 227 246 248 273 297 313 413 456 FLOATATION, 158 302 FLOOR, 158 239 FLOOR COVERING, 86 FLOW DIAGRAM, 378 FLOW PROPERTIES, 192 FLOW RATE, 273 275 344 FLOW RESTRICTION, 103 FLUORINE, 404 FLUOROHYDROCARBON, 222 FOAM-CORE, 302 366 FOAM-FILLED, 248 FOAM INJECTION, 248 296 FOAM RISE, 262 296 FOAMING TEMPERATURE, 157 FOGGING, 58 FOOD-CONTACT APPLICATION, 101 196 FOOD PACKAGING, 3 30 54 80 91 101 140 177 194 220 244 249 311 381 388 408 411 445 446 FOOTBALL, 33 FOOTWEAR, 33 62 73 76 90 108 113 179 208 267 437 452 FORM-FILL-SEAL, 101 244 FORMING, 3 165 194 229 422 454 FORMULATION, 14 15 49 51 59 107 253 280 281 282 304 306

124

FOURIER TRANSFORM INFRARED SPECTROSCOPY, 101 285 374 FRACTION, 57 FRACTURE MORPHOLOGY, 2 5 8 15 17 20 24 32 45 48 50 51 52 61 68 81 88 128 132 134 135 153 172 193 198 207 218 219 226 245 259 269 276 FRACTURE SURFACE, 273 275 315 FRAGMENTATION, 316 FREE RADICALS, 177 257 385 FREE-RADICAL INITIATOR, 186 221 247 FREEZING POINT, 339 FREON, 435 FRIABILITY, 262 FRICTION, 85 FUNCTIONALITY, 49 84 121 177 FURNACE BLACK, 40 FURNITURE, 312 368 379 409 FUSION, 102 188 316 FUSION BONDING, 318

G GAMMA-IRRADIATION, 285 GAS ABSORPTION, 185 235 315 GAS ANALYSIS, 316 GAS COUNTERPRESSURE, 269 421 GAS DESORPTION, 315 GAS DIFFUSION, 262 303 314 315 345 380 GAS EVOLUTION, 14 135 206 303 GAS EXCHANGE, 404 GAS FORMATION, 169 GAS INJECTION, 311 365 378 GAS INJECTION MOULDING, 46 GAS PERMEABILITY, 85 101 236 255 303 345 380 GAS-PHASE, 139 167 199 206 210 213 235 266 270 303 GAS RELEASING, 81 GAS SOLUBILITY, 233 273 314 315 339 344 433 GAS TRANSPORT, 380 GASIFICATION, 80 199 GEL, 285 308 416 GEL CONTENT, 17 49 65 84 157 184 206 GEL FRACTION, 16 84 285 303 423 GEL PERMEATION CHROMATOGRAPHY, 136

GEL POINT, 7 GELLING, 7 262 GLASS FIBRE, 221 GLASS FIBRE-REINFORCED PLASTIC, 165 246 263 312 368 425 456 GLASS MAT, 246 368 GLASS MICROSPHERE, 89 GLASS TRANSITION TEMPERATURE, 8 101 246 288 305 316 339 GLOVE BOX, 91 GLYCEROL ESTER, 147 GLYCEROL MONOSTEARATE, 68 342 GLYCERYL MONOSTEARATE, 347 GLYCIDYL GROUP, 334 GLYCOL POLYMER, 185 235 GOLD, 436 GONIOMETRY, 262 GRAFT COPOLYMER, 124 190 197 200 GRAFT COPOLYMERISATION, 247 427 GRAFT POLYMERISATION, 146 427 GRAFTING, 120 374 GRAIN SIZE, 95 GRANULE, 137 GRAVIMETRIC ANALYSIS, 24 152 226 GROWTH RATE, 27 302 GUANIDINE, 168

H HALF-LIFE, 247 HALOGEN-FREE, 165 251 321 HALOGENATION, 86 HARDNESS, 16 50 53 76 83 99 128 168 242 266 271 384 HCFC, 92 262 296 299 314 344 353 354 HCFC-141B, 262 296 299 HCFC-142B, 344 HCFC-22, 314 344 HCFC-FREE, 175 182 HEAD REST, 91 297 HEADLINER, 22 302 HEALTH HAZARDS, 196 248 HEAT ACTIVATION, 365 HEAT AGEING, 297 299 HEAT CAPACITY, 359 HEAT DEFLECTION TEMPERATURE, 165 194 279 302 368 HEAT DEGRADATION, 135 253

© Copyright 2004 Rapra Technology Limited

Subject Index

HEAT DISTORTION TEMPERATURE, 165 194 HEAT EXCHANGER, 345 HEAT FLOW, 67 299 HEAT FLUX, 299 HEAT INSULATION, 4 30 39 72 91 111 160 164 165 181 194 244 260 262 263 289 HEAT LOSS, 262 359 HEAT OF EVAPORATION, 88 HEAT OF FUSION, 315 HEAT RESISTANCE, 76 85 120 139 148 163 186 189 190 195 246 249 260 300 311 355 361 381 388 390 391 408 446 HEAT-SEALING, 120 189 190 300 HEAT SHRINKAGE, 76 HEAT STABILITY, 393 424 HEAT TRANSFER, 67 85 151 168 213 270 299 314 359 HEAT TREATMENT, 174 246 HEATING, 62 71 73 88 103 144 148 152 159 168 169 194 198 199 205 221 265 270 271 273 296 304 316 332 343 370 HEATING PRESS, 208 HEATING RATE, 35 168 316 HELIUM, 404 HELMET, 37 167 279 295 419 HENRY’S LAW, 339 344 HEPTAFLUOROPROPANE, 353 354 HEPTANE, 245 HFC, 92 222 353 354 HFC FREE, 182 HFC-152A, 335 HIGH DENSITY POLYETHYLENE, 10 12 18 19 46 67 74 95 107 131 132 133 153 204 215 224 234 263 283 303 312 313 315 325 326 377 378 385 387 400 419 423 443 456 HIGH IMPACT POLYPROPYLENE, 368 HIGH IMPACT POLYSTYRENE, 296 329 HOCKEY, 437 HOLLOW ARTICLE, 420 HOLLOW BODY, 95 HOMOGENISATION, 88 220 245 259 356 361 HOMOPOLYMER, 193 249 260 HONEYCOMB STRUCTURE, 38 165 HORSE RIDING, 313 HORTICULTURAL APPLICATION, 91 HOSPITAL, 111

HOT AIR VULCANISATION, 14 HOT MELT ADHESIVE, 246 296 HOT PRESSING, 165 HOT STAGE MICROSCOPY, 198 315 HOT-WATER PIPE, 434 HYDRAULIC MOTOR, 73 HYDRAZIDE, 293 HYDROCARBON, 86 92 316 332 353 354 HYDROCARBON OIL, 385 HYDROCEROL, 275 284 HYDROCHLOROFLUOROCARBON, 92 262 296 299 314 344 353 354 411 HYDROFLUOROCARBON, 92 222 353 354 HYDROGEN, 316 HYDROGEN CYANIDE, 374 HYDROHALOCARBON COMPOUND, 92 222 HYDROLYSABLE, 177 HYDROLYTIC STABILITY, 297 HYDROPHILICITY, 139 427 HYSTERESIS, 50 53 128 213 270 317

I IMAGE ANALYSIS, 57 IMMISCIBILITY, 5 IMPACT, 38 41 254 297 419 IMPACT PROPERTIES, 13 22 33 34 37 38 41 44 64 70 82 85 87 89 91 98 101 119 141 153 160 167 194 195 215 246 254 263 264 271 273 295 302 313 320 325 334 381 400 412 417 418 419 438 452 456 IMPACT RESISTANCE, 37 91 141 211 263 279 418 452 IMPACT STRENGTH, 13 34 85 101 119 153 160 194 195 215 246 271 273 287 297 303 368 IMPREGNATION, 265 332 374 389 IN-MOULD SKINNING, 302 INCONTINENCE PRODUCT, 150 INDENTATION, 271 INDUSTRIAL APPLICATION, 181 242 INFRARED SENSOR, 85 INFRARED SPECTROSCOPY, 101 138 149 255 307 385 INHIBITORS, 86 92 INITIATORS, 186 221 247 INJECTION MOULD, 62 73 316 339 368

© Copyright 2004 Rapra Technology Limited

INJECTION MOULDING, 13 44 45 46 56 62 73 83 91 92 117 145 171 218 219 248 263 267 269 288 322 329 406 418 421 439 449 INJECTION MOULDING MACHINE, 62 73 INJECTION PRESSURE, 62 73 83 288 296 INJECTION SPEED, 62 73 288 INJECTION STRETCH BLOW MOULDING, 312 INJECTION TEMPERATURE, 62 73 83 296 INJECTION TIME, 73 INJECTION UNIT, 73 INJECTION VOLUME, 62 73 INSOLE, 108 179 INSULATION, 4 30 39 72 91 92 111 127 160 164 165 175 180 181 182 194 244 248 249 259 260 262 263 272 303 309 345 352 377 381 392 403 405 426 442 INSULATION PROPERTIES, 420 INTEGRAL SKIN, 302 INTEGRAL SKIN FOAM, 176 192 279 301 439 INTERFACIAL ADHESION, 246 INTERFACIAL PROPERTIES, 388 INTERMEDIATE BULK CONTAINER, 263 INTERNAL MIXING, 169 INTERNAL PRESSURE, 332 INTERNAL STRESS, 368 INTERPOLYMER, 76 131 175 180 182 INTRAMOLECULAR MOTION, 393 INTRINSIC VISCOSITY, 114 INVESTMENT, 98 111 161 391 397 IODINE VALUE, 136 ION IMPLANTATION, 436 IONENE POLYMER, 47 129 IONISING RADIATION, 221 IONOMER, 47 129 351 IRON, 316 IRRADIATION, 16 183 257 374 423 IRRADIATION CROSSLINKING, 84 92 157 IRRADIATION POLYMERISATION, 427 ISOBUTANE, 16 30 47 147 170 307 327 328 330 335 342 345 347

125

Subject Index

ISOCYANATE, 92 262 296 ISOCYANATE INDEX, 262 ISOPENTANE, 207 273 275 284 ISOPRENE COPOLYMER, 186 ISOPRENE-STYRENE COPOLYMER, 178 ISOTROPY, 345 IZOD, 215 246 273

K K VALUE, 262 299 KAYAK, 192 KELVIN FOAM, 206 KINETIC ENERGY, 368 KINETICS, 11 258 314 315 316 KNEADING, 186 KNEE BOLSTER, 302

L LAMELLAE, 88 245 LAMINATE, 101 102 109 158 162 181 194 212 296 299 318 322 334 338 362 364 385 451 LAMINATED FILM, 368 LAMINATED GLASS, 165 LAMINATION, 3 58 242 LANGIVIN EQUATION, 2 7 14 22 23 38 40 55 68 LATENT HEAT, 88 359 LATEX, 92 LAYER, 110 181 LEACHING, 52 LEGISLATION, 92 297 345 352 LIFE-JACKET, 214 LIFE-SAVING DEVICE, 214 348 LIFETIME PREDICTION, 299 LIGHT MICROSCOPY, 142 219 LIGHT SCATTERING, 218 LINE SPEED, 365 LINEAR LOW, 303 LINEAR LOW DENSITY POLYETHYLENE, 29 35 66 70 71 100 109 119 120 122 132 142 153 172 189 190 191 198 226 227 281 283 300 307 312 331 346 349 355 LINING, 22 262 296 302 426 LIQUID CRYSTAL POLYMER, 165 LIQUID NITROGEN, 271 LIVING HINGE, 302 LOAD CELL, 85 LOAD-DEFLECTION, 410 LOADING, 43 303 313 LONG CHAIN, 207

126

LONG CHAIN BRANCHING, 249 257 LONG FIBRE, 165 368 LOSS FACTOR, 94 LOSS MODULUS, 243 LOSS TANGENT, 55 94 243 LOST-FOAM CASTING, 316 LOST PATTERN PROCESS, 316 LOW DENSITY POLYETHYLENE, 16 19 20 32 33 44 47 49 57 61 65 69 70 77 80 84 88 94 109 122 131 132 142 147 153 158 175 178 180 184 185 189 190 199 200 206 210 213 217 219 224 231 232 233 236 238 241 249 251 255 258 266 270 271 277 281 283 285 286 300 303 307 312 313 314 321 325 339 345 346 349 359 372 377 378 380 383 394 423 443 451 LOW TEMPERATURE PROPERTIES, 263 297 439 LUBRICATION, 52 92 184 271 LUGGAGE, 451 LUMPING, 344

M MACHINERY, 14 56 62 68 73 85 87 98 106 111 121 170 171 194 208 233 240 260 263 267 268 269 271 273 284 287 311 312 314 316 329 331 344 356 359 MACROSCOPIC PROPERTIES, 295 MAGIC ANGLE SPINNING, 101 MAGNESIUM SILICATE, 359 MALEIC ANHYDRIDE COPOLYMER, 21 MARKET ANALYSIS, 92 MARKET GROWTH, 27 MARKET SHARE, 98 161 163 452 MARKET SURVEY, 445 MARKET TREND, 92 230 MASS FRACTION, 345 MASS RATIO, 345 MASS TRANSFER, 314 MASS TRANSPORT, 236 MASTERBATCH, 95 142 169 344 MATERIALS HANDLING, 426 428 MATERIALS REPLACEMENT, 33 80 92 140 165 175 194 214 246 279 287 365 407 411 413 452 MATERIALS SELECTION, 8 9

MATHEMATICAL MODEL, 1 57 60 149 236 240 332 387 MATRIX, 49 MATT FINISH, 179 MATTRESS, 389 MDI, 262 MEAT PACKAGING, 194 MECHANICAL ENERGY, 317 MECHANICAL PARTS, 168 169 248 MECHANICAL RELAXATION, 236 MECHANICAL STRENGTH, 139 148 289 305 MEDICAL APPLICATIONS, 58 111 150 447 454 MEDICAL EQUIPMENT, 111 163 MEDIUM-DENSITY POLYETHYLENE, 271 281 287 377 378 MELT COMPOUNDING, 112 118 MELT ELASTICITY, 273 276 314 MELT ELONGATION, 249 MELT FLOW, 217 333 336 344 346 367 401 443 MELT FLOW INDEX, 36 84 96 97 120 122 137 189 190 200 271 273 276 300 319 337 361 411 MELT FLOW RATE, 102 107 139 252 349 MELT FLOW STABILITY, 260 MELT FRACTURE, 336 346 349 367 MELT PRESSURE, 193 194 MELT PROCESSING, 203 MELT PUMP, 144 MELT RHEOLOGY, 326 MELT STABILITY, 80 MELT STRENGTH, 30 31 46 47 64 72 81 131 156 170 173 183 193 194 225 230 249 257 260 273 283 287 317 350 369 401 408 MELT TEMPERATURE, 78 142 194 204 217 234 269 316 339 344 345 359 MELT TENSION, 102 251 287 321 MELT VISCOSITY, 156 186 194 314 344 MELT VISCOSITY INDEX, 36 122 137 271 273 276 MELTING, 65 145 205 215 315 316 MELTING POINT, 21 44 79 85 96 101 107 125 139 188 193 219 310 315 339 368 402 416 440 MELTING TEMPERATURE, 79 246 273

© Copyright 2004 Rapra Technology Limited

Subject Index

MELTS, 47 186 203 204 205 269 339 433 435 MERCURY POROSIMETRY, 326 MESOPORE, 245 METAL, 248 316 METAL ADHESION, 196 248 METAL ALLOY, 316 METAL CASTING, 316 METAL COMPLEX, 385 METAL DEACTIVATOR, 385 METAL ION, 351 METAL OXIDE, 278 METAL SALT, 103 METALLOCENE, 5 7 31 84 86 93 100 107 182 223 224 232 237 241 292 METALLOCENE COPOLYMER, 196 METALLURGY, 316 METHACRYLATE POLYMER, 419 METHACRYLIC ACID COPOLYMER, 103 METHYL ACRYLATE, 248 METHYL ACRYLATE COPOLYMER, 17 METHYL BENZIMIDAZOLYL CARBAMATE, 239 METHYL METHACRYLATE COPOLYMER, 316 METHYLENE CHLORIDE, 88 METHYLENE GROUP, 361 MFI, 36 122 137 271 273 276 MICROBALLOON, 89 MICROBEAD, 305 MICROFIBRE, 134 MICROGRAPHY, 10 53 149 MICROPELLET, 265 MICROPROCESSOR, 164 MICROSCOPY, 10 87 143 149 191 198 218 226 255 344 MICROSPHERE, 127 134 245 MICROSTRUCTURE, 39 88 273 275 295 315 MICROWAVE, 388 MICROWAVE ABSORPTION, 168 MICROWAVE HEATING, 168 MICROWAVE OVEN, 72 408 445 MICROWAVE VULCANISATION, 168 MILDEW RESISTANCE, 239 MILITARY APPLICATIONS, 419 428 MISCIBILITY, 134 MISSILE, 91 MIXING, 14 88 98 108 112 168 169 199 201 229 262 265 273 296 298 303 311 344 365

MODIFIED ATMOSPHERE, 194 249 MODULUS, 1 23 49 50 53 85 128 169 303 341 394 MOISTURE, 139 MOISTURE BARRIER, 351 MOISTURE CONTENT, 139 MOISTURE CURING, 146 MOISTURE REGAIN, 427 MOISTURE RESISTANCE, 434 453 MOISTURE VAPOUR TRANSMISSION, 37 MOLE FRACTION, 339 MOLECULAR MOTION, 393 MOLECULAR STRUCTURE, 49 72 81 107 140 189 190 193 216 228 249 258 259 273 303 317 383 388 449 MOLECULAR WEIGHT, 9 18 65 69 109 120 133 136 246 255 257 263 300 307 312 316 334 336 339 346 349 367 416 MOLECULAR WEIGHT DISTRIBUTION, 9 65 69 93 114 120 189 190 200 319 300 333 336 346 349 367 MONITORING, 26 MONOLAYER, 287 MONOMER, 177 316 361 MONOMER RATIO, 9 MONTREAL PROTOCOL, 92 345 MOONEY VISCOMETER, 14 MOONEY VISCOSITY, 9 136 169 293 MOULD, 62 73 85 111 155 242 316 386 MOULD CAVITY, 323 373 MOULD CLOSING, 62 73 MOULD COOLING, 62 315 MOULD CYCLE, 111 MOULD FILLING, 316 MOULD HEATING, 62 108 MOULD-IN-PLACE, 297 MOULD MAKING, 111 MOULD OPENING, 62 73 MOULD PACKING, 296 MOULD PRESSURE, 373 MOULD RELEASE AGENT, 92 MOULD SHRINKAGE, 62 MOULD TEMPERATURE, 62 73 83 87 160 296 364 MOULDABILITY, 290 361 MOULDABLE, 399 MOULDED, 137 139 159 211 221 264 297 MOULDING COMPOUND, 62 73 108 125

© Copyright 2004 Rapra Technology Limited

MOULDING FAULT, 73 MOULDING PRESSURE, 62 73 312 MOULDINGS, 323 MOULDMAKING, 111 MOULDS OF POLYMERS, 316 MULTIAXIAL, 312 MULTI-COLOUR, 311 MULTILAYER, 4 67 80 87 101 102 104 119 263 287 311 312 334 373 MULTI-STATION, 62 73

N NANOCOMPOSITE, 21 NAPHTHALENE, 416 NAPPY, 150 NATURAL FIBRE-REINFORCED PLASTIC, 24 NATURAL RUBBER, 14 NEOPRENE, 196 NEUTRALISATION, 351 NEWTONIAN, 212 NITROGEN, 20 39 61 88 151 163 185 201 224 233 235 298 303 306 339 365 374 380 394 419 433 435 NOISE INSULATION, 30 160 181 182 248 NOISE REDUCTION, 248 NOMENCLATURE, 207 215 NON-CROSSLINKED, 165 166 247 331 NON-HALOGENATED, 251 NON-ISOTHERMAL, 168 314 NON-LINEAR, 82 NOTCHED IMPACT STRENGTH, 271 273 NUCLEAR APPLICATION, 436 NUCLEAR MAGNETIC RESONANCE, 101 385 NUCLEATING AGENT, 2 74 75 85 101 107 117 183 193 194 205 207 271 275 276 280 294 314 342 344 347 416 440 NUCLEATION, 2 6 19 23 25 54 74 81 85 88 95 101 123 169 194 198 207 217 226 273 275 282 284 303 314 315 341 344 359 387 435 440 442 NUMBER-AVERAGE MOLECULAR WEIGHT, 65

O OBTURATOR, 85 OCTENE COPOLYMER, 7 50 53

127

Subject Index

84 128 OFFICE FURNITURE, 368 OFFSHORE APPLICATION, 141 OIL CONTENT, 169 OIL EXTENSION, 169 OIL RESISTANCE, 414 OILS, 150 169 OLEFIN, 395 OLEFIN COPOLYMER, 53 84 104 107 120 122 137 148 150 189 190 197 200 252 293 300 332 OPEN CELL, 16 101 146 168 169 197 243 245 262 273 303 326 357 374 389 427 447 448 OPTICAL CABLE, 271 OPTICAL MICROGRAPH, 14 OPTICAL MICROSCOPY, 191 218 226 315 416 456 OPTICAL PROPERTIES, 5 59 62 73 85 296 299 316 368 OPTIMISATION, 54 127 168 169 210 ORIENTATION, 38 45 59 193 218 318 449 ORTHOPHTHALIC POLYESTER RESIN, 246 OVENWARE, 446 OXIDATION, 285 385 OXIDATIVE DEGRADATION, 285 316 385 OXIDATIVE STABILITY, 377 OXIDISATION, 316 OXYBISBENZENE SULFONYLHYDRAZIDE, 14 169 OXYGEN, 419 OXYGEN ABSORPTION, 385 OXYGEN INDEX, 374 OZONE DEPLETION, 303 345

P PACKAGING, 3 30 43 58 72 80 85 91 92 98 101 102 144 166 173 181 184 194 214 220 230 237 242 246 249 260 261 279 302 303 311 312 320 324 325 368 381 386 388 408 409 410 411 414 415 417 422 426 445 450 453 454 PACKAGING APPLICATION, 242 289 382 415 450 453 454 PACKAGING CONTAINER, 408 411 421 445 PACKAGING FILM, 368 PACKAGING WASTE, 246 PACKING PRESSURE, 288 PADDING, 41

128

PAINTABILITY, 368 PALLET, 192 263 312 368 PANEL, 234 246 296 PARACRYSTALLINE, 85 PARISON, 102 312 420 PARTICLE, 242 247 332 PARTICLE ACCELERATOR, 436 PARTICLE SIZE, 101 169 260 271 344 PEEL STRENGTH, 188 196 PENDULUM TEST, 101 PENTANE, 411 PERMANENT SET, 418 PERMEABILITY, 52 85 101 138 253 254 255 261 266 299 307 434 PEROXIDE, 100 130 148 151 248 303 PHARMACEUTICAL APPLICATION, 454 PHASE BEHAVIOUR, 134 215 PHASE MORPHOLOGY, 215 PHASE SEPARATION, 88 134 PHASE TRANSITION, 44 218 PHENOLIC ANTIOXIDANT, 385 PHENOLIC RESIN, 92 363 PHENYLENE OXIDE POLYMER, 445 PHOTOMICROGRAPHY, 53 419 PHTHALIC ANHYDRIDE, 262 PHYSICAL PROPERTIES, 39 44 50 79 83 85 96 101 107 125 128 139 178 188 189 190 192 193 208 219 283 304 327 330 341 399 402 410 456 PHYSICOCHEMICAL PROPERTIES, 316 PIGMENT, 54 85 101 360 PIPE, 4 271 365 390 403 431 PIPE WRAPPING, 434 PIPELINE, 141 PLANT CAPACITY, 386 PLANT CONSTRUCTION, 161 163 366 386 391 397 398 414 PLANT EXPANSION, 98 PLASTICISATION, 62 73 273 314 315 PLASTICISE, 56 235 271 PLASTICISER, 150 185 208 PLASTIFICATION, 287 PLASTOMER, 104 PLATEN, 304 PLIABILITY, 141 POISSON’S RATIO, 33 266 270 POLARISATION MICROSCOPY, 315 POLARISED LIGHT MICROSCOPY, 142 219

POLLUTION CONTROL, 352 POLYACETAL, 456 POLYALKENE, 15 20 21 39 52 61 63 64 82 84 88 92 94 100 120 129 132 135 152 153 166 167 174 177 178 183 196 204 209 223 224 232 238 241 245 254 259 266 269 POLYAMIDE, 248 312 POLYCARBONATE, 13 111 POLYCHLOROPRENE, 196 375 403 POLYENE, 120 POLYEPOXIDE, 4 246 POLYESTER POLYOL, 92 262 POLYESTER RESIN, 246 POLYESTER-URETHANE, 262 POLYETHER POLYOL, 92 262 POLYETHER URETHANE, 262 POLYETHYLENE TEREPHTHALATE, 28 79 229 246 312 381 391 445 POLYGLYCOL, 185 235 POLYIMIDE, 389 POLYIONENE, 47 129 POLYISOCYANURATE, 299 375 POLYMERIC ADDITIVE, 235 POLYMERIC CARRIER, 234 POLYMERIC MICROSPHERE, 89 POLYMERIC PLASTICISER, 185 POLYMERIC PROPERTY MODIFIER, 109 POLYMERIC REINFORCEMENT, 165 POLYMERIC TACKIFIER, 150 POLYMERISATION, 70 114 180 246 POLYMERISATION CATALYSTS, 7 31 93 107 114 196 223 224 232 241 249 292 POLYMERISATION COCATALYST, 292 POLYMERISATION INHIBITOR, 427 POLYMERISATION INITIATOR, 247 POLYMERISATION TEMPERATURE, 247 POLYMETHACRYLATE, 419 POLYMETHACRYLIMIDE, 286 POLYMETHYLMETHACRYLATE, 111 203 316 POLYOL, 92 262 296 371 372 POLYPHENYLENE OXIDE, 38 297 381 445 POLYSTYRENE, 38 80 91 92 98 121 131 194 203 214 222 229 231 246 260 272 287 295 296

© Copyright 2004 Rapra Technology Limited

Subject Index

297 303 311 316 317 325 340 344 353 354 359 363 371 378 386 402 419 430 445 456 POLYUREA, 262 POLYURETHANE, 38 73 92 111 141 149 165 208 223 246 262 277 295 296 297 299 317 363 375 389 431 438 452 POLYURETHANE ELASTOMER, 37 POLYURETHANE ESTER, 262 POLYVINYL BUTYRAL, 165 POLYVINYL CHLORIDE, 92 196 208 246 277 287 353 354 378 POLYVINYLBENZENE, 80 92 203 260 PORE SHAPE, 52 PORE SIZE, 52 129 245 285 416 PORE STRUCTURE, 88 153 POROSIMETRY, 326 POROSITY, 10 39 52 129 243 245 384 416 448 PORTABLE, 111 POST CURING, 62 73 POST-EXTRUSION, 339 345 POST-MOULD, 62 POUR-IN-PLACE, 262 POWDER, 119 130 169 212 264 334 PRECIPITATION, 128 PREFORM, 312 PREFORMING, 248 PRESS MOULDING, 221 PRESSURE CONTROL, 62 73 144 194 PRESSURE DEPENDENCE, 19 83 PRESSURE DROP, 194 204 207 273 314 344 PRESSURE FORMING, 92 PRESSURE RESISTANCE, 99 PRESSURE SENSITIVE TAPE, 196 277 PRINTED CIRCUIT, 444 PROCESS CONTROL, 35 62 73 85 365 PROCESSABILITY, 5 30 31 35 66 69 72 78 87 154 189 190 283 287 327 330 401 402 405 PROCESSING, 6 14 15 16 21 48 52 56 80 92 120 127 169 170 192 204 207 215 218 229 238 269 280 288 301 304 384 389 415 431 440 441 443 PROCESSING AID, 92 PRODUCT DEVELOPMENT, 37 144 PRODUCT LIABILITY, 297

PRODUCTION CAPACITY, 98 161 163 366 391 448 PRODUCTION COST, 62 73 311 PRODUCTION RATE, 365 PROPANE, 134 245 335 342 347 PROPENE COPOLYMER, 21 59 101 114 124 125 137 183 186 193 205 209 224 247 PROPYLENE COPOLYMER, 21 59 101 114 124 125 137 183 186 193 205 209 224 247 368 383 439 PROPYLENE-ETHYLENE COPOLYMER, 96 101 103 137 183 PROTECTIVE AGENT, 426 PROTECTIVE CLOTHING, 33 37 41 295 313 419 PROTECTIVE PACKAGING, 181 279 295 398 PROTOTYPE, 62 73 PTFE, 419 PULL TEST, 296 PULLING FORCE, 47 PULLING SPEED, 47 PULVERISATION, 121 PUNCTURE RESISTANCE, 141 PURITY, 58 PYROLYSIS, 316

Q Q VALUE, 136 QUALITY, 73 80 168 QUALITY CONTROL, 62 73 85 296 QUENCHING, 88 273 315

R R-VALUE, 299 RADIATION ABSORPTION, 436 RADIATION CROSSLINKING, 84 92 157 303 RADIATION CURING, 16 184 285 RADIATION GRAFT, 374 RADIATION POLYMERISATION, 427 RADIO FREQUENCY INSULATION, 378 RAILWAY APPLICATION, 165 RANDOM COPOLYMER, 31 101 103 125 137 312 355 368 REACTION INJECTION MOULDING, 111 REACTIVE BLENDING, 28 368

© Copyright 2004 Rapra Technology Limited

REACTIVE EXTRUSION, 28 170 REACTIVE POLYMER, 395 REACTIVE PROCESSING, 170 REBOUND RESILIENCE, 76 113 RECIPROCATING SCREW, 56 RECLAIMING, 48 85 92 109 230 246 324 340 368 397 RECREATIONAL APPLICATION, 426 RECRYSTALLISATION, 315 RECYCLABILITY, 80 121 165 192 221 242 279 331 RECYCLING, 12 31 91 92 121 126 192 214 221 230 242 246 279 311 324 368 382 386 390 395 397 410 REFLECTANCE SPECTROSCOPY, 149 REGENERATION, 208 REGRESSION ANALYSIS, 299 REGRIND, 54 REINFORCED PLASTICS, 12 13 24 55 74 89 141 165 187 195 212 246 263 312 322 368 425 REINFORCED RUBBER, 40 REINFORCED THERMOPLASTIC, 246 368 RELATIVE DENSITY, 53 55 RELATIVE HUMIDITY, 271 RELAXATION TIME, 314 RELEASE AGENT, 92 REPRODUCIBILITY, 377 RESEARCH, 54 85 RESIDENCE TIME, 24 168 RESIDUAL STRESSES, 168 RESILIENCE, 76 101 111 113 129 133 184 194 211 264 279 334 389 424 RESIN, 97 112 120 129 155 202 212 221 RESIN TRANSFER MOULDING, 246 RESPONSE SURFACE METHODOLOGY, 38 RHEOLOGICAL PROPERTIES, 5 7 14 15 18 21 30 34 36 47 48 53 66 69 70 72 79 101 112 168 169 170 171 173 193 194 222 226 246 262 271 273 283 296 303 314 344 359 368 396 401 402 408 443 RHEOLOGY, 5 7 18 21 30 34 36 47 48 66 69 70 72 79 101 112 168 169 170 171 173 193 194 222 246 262 271 273 396 RHEOMETER, 14 170 198 222 243 RHEOMETRY, 168 226

129

Subject Index

RIGIDITY, 92 110 146 192 194 221 262 263 296 297 311 318 364 368 388 389 RISE RATE, 262 ROLL FORMING, 165 ROOFING, 221 299 405 430 ROTATIONAL BLOW MOULDING, 34 35 ROTATIONAL MOULDING, 15 23 34 35 51 87 112 118 119 130 152 160 176 187 191 192 198 226 227 337 ROTATIONAL RHEOMETER, 198 ROUGHNESS, 271 RUBBER, 9 11 14 40 43 62 73 84 111 126 128 136 143 148 149 153 168 169 179 187 196 197 206 208 211 212 229 248 250 262 264 274 288 293 294 299 329 341 362 368 371 372 384 452 RUBBER-MODIFIED, 179 288 RUBBER-TOUGHENED, 179 RUNNING SHOE, 90

S SAFETY, 38 62 297 317 SAFETY HELMET, 279 SAG RESISTANCE, 287 SAND, 316 SAND EROSION, 455 SANDAL, 62 SANDWICH CONSTRUCTION, 242 SANDWICH MOULDING, 322 SANDWICH PANEL, 246 SANDWICH STRUCTURE, 13 111 242 246 248 318 430 438 SATURATION TIME, 315 SBR, 196 SCALING LAW, 82 SCANNING ELECTRON MICROGRAPH, 5 72 151 210 224 SCANNING ELECTRON MICROSCOPY, 5 10 21 32 50 72 90 128 132 151 153 207 210 215 224 259 273 275 286 307 310 315 341 396 400 416 419 SCORCH, 168 SCORCH INHIBITOR, 92 SCORCH TIME, 168 SCRAP, 62 73 246 368 SCRAP POLYMER, 48 109 115 121 SCRAP REDUCTION, 62 73 410

130

SCREENCHANGER, 144 SCREW, 56 62 73 194 SCREW DESIGN, 144 193 SCREW EXTRUDER, 19 95 142 144 172 SCREW FLIGHT, 194 SCREW SPEED, 83 127 142 194 271 273 SEAL, 165 168 237 248 SEALANT, 150 351 429 SEALING, 426 SEAT, 91 162 368 SEED TRAY, 98 SEMICONDUCTOR, 27 SEMICRYSTALLINE, 20 85 215 440 SENSITISER, 84 SENSOR, 85 138 SEPARATING AGENT, 199 SEPARATION, 199 SEQUENTIAL COEXTRUSION, 312 SEQUENTIAL INJECTION MOULDING, 302 SERVICE LIFE, 52 164 299 429 SHAPE FACTOR, 314 SHAPE-MEMORY, 293 SHEAR, 6 167 217 314 344 387 SHEAR ENERGY, 6 SHEAR FORCE, 344 SHEAR MODULUS, 40 169 SHEAR PROPERTIES, 5 22 123 222 246 262 SHEAR RATE, 69 273 314 336 344 346 349 367 387 SHEAR RHEOLOGY, 18 SHEAR STRENGTH, 246 262 SHEAR STRESS, 222 SHEAR THINNING, 5 SHEAR VISCOSITY, 176 402 SHEARING, 89 SHEET, 54 57 61 63 70 80 85 86 101 104 108 110 123 129 141 158 169 193 194 199 216 221 234 242 244 246 249 259 260 261 276 287 296 303 305 314 315 340 343 359 370 381 388 390 408 409 411 426 446 447 448 454 SHINGUARD, 33 SHIPPING CONTAINER, 312 SHOCK ABSORPTION, 72 175 180 181 405 414 451 453 SHOCK ABSORBING PACKAGING, 30 102 162 320 324 325 382 447 SHOE, 62 73 90 SHOE SOLE, 90 155 179

SHOT SIZE, 15 SHRINKAGE, 62 73 85 87 100 105 160 227 262 296 297 393 SILANE, 177 190 237 SILANE COPOLYMER, 197 SILANE GROUP, 120 196 SILICA, 11 43 53 341 SILICATE, 2 75 107 117 SILICON COPOLYMER, 107 SILICON DIOXIDE, 11 43 53 SILICONE COPOLYMER, 107 SIMULATION, 67 85 217 258 270 296 314 380 SINGLE-COMPONENT, 111 SINGLE-SCREW EXTRUDER, 48 68 95 142 144 172 194 271 273 275 276 280 SINGLE SITE CATALYSIS, 175 SINTER, 317 SINTERING, 15 350 369 SKIN, 110 111 130 246 312 377 385 SKIN-CORE, 35 SKIN FORMATION, 35 SKIN-INSERT MOULDING, 98 SLABSTOCK, 92 SLAG, 115 SLIT DIE, 6 SLOT DIE, 6 SLURRY, 265 SODIUM BENZOATE, 54 SODIUM BICARBONATE, 10 75 101 142 253 303 SOFT-TOUCH, 175 195 SOFTENING, 297 SOFTENING POINT, 265 SOFTENING TEMPERATURE, 103 332 SOFTNESS, 148 180 297 311 384 SOFTWARE, 38 SOLES, 33 62 73 76 90 155 179 452 SOLID STATE, 101 246 SOLID STATE POLYMERISATION, 246 SOLUBILITY, 17 168 215 273 314 315 339 344 SOLUBILITY PARAMETER, 134 262 SOLUTE, 339 SOLUTION, 20 39 88 245 SOLUTION POLYMERISATION, 70 SOLUTION VISCOSITY, 314 SOLVENT, 245 305 310 416 SOLVENT ABSORPTION, 310 SOLVENT EXTRACTION, 310 SOLVENT REMOVAL, 416

© Copyright 2004 Rapra Technology Limited

Subject Index

SOLVENT RESISTANCE, 165 SOLVOLYSIS, 92 SORPTION, 171 215 307 315 403 433 SOUND ABSORPTION, 182 214 243 376 SOUND DAMPING, 302 SOUND INSULATION, 30 160 165 181 182 248 376 422 SOYBEAN OIL, 208 SPECIFIC GRAVITY, 148 165 208 287 341 SPECTROSCOPY, 149 385 SPHERULITE, 85 315 SPHERULITIC GROWTH, 85 SPONGE, 9 168 169 SPORTS APPLICATION, 33 318 452 SPORTS EQUIPMENT, 37 163 167 279 303 437 451 SPORTS SHOE, 33 62 73 76 437 452 SPORTSWEAR, 41 437 SPRAY DRYING, 74 SPRUE, 269 STABILISATION, 73 76 81 116 195 199 246 249 273 365 STABILISER, 92 205 228 371 372 385 STAMPING, 364 STANDARD, 22 92 297 313 377 419 STATIC DISSIPATION, 91 98 STATIC ELECTRICITY, 426 427 444 447 450 STATIC ELECTRICITY ELIMINATOR, 106 STATIC MECHANICAL PROPERTIES, 238 STATIC PROPERTIES, 297 STATIC RESISTANCE, 261 STATISTICAL ANALYSIS, 22 STATISTICAL COPOLYMER, 312 355 368 STATISTICAL MODEL, 38 STATISTICS, 27 92 163 324 445 STEARAMIDE, 147 STEARATE, 359 STEEL, 419 431 STEREOREGULAR POLYMERISATION, 114 STIFFNESS, 4 77 85 160 177 194 214 227 248 297 313 413 STORAGE LIFE, 380 STORAGE MODULUS, 55 60 94 99 STRAIN, 40 55 167 261 270 314 317 380 419

STRAIN AT BREAK, 168 STRAIN GAUGE, 296 STRAIN HARDENING, 66 205 213 257 270 287 STRAIN RATE, 39 43 82 178 STRENGTH, 58 111 120 165 189 190 260 300 312 318 426 437 446 STRESS, 43 166 168 206 254 261 266 281 303 314 318 402 STRESS ANALYSIS, 303 STRESS CRACK RESISTANCE, 260 STRESS CRACKING, 296 368 STRESS RELAXATION, 50 89 128 223 STRESS-STRAIN PROPERTIES, 14 40 43 82 90 168 206 213 225 254 266 268 270 303 325 363 380 400 417 419 432 STRETCH BLOW MOULDING, 312 STRETCH RATIO, 296 344 STRETCHING, 59 206 271 344 STRUCTURAL FOAM, 45 64 165 263 269 318 418 449 456 STRUCTURAL PART, 302 STRUCTURAL PROPERTIES, 75 STRUCTURE-PROPERTY RELATIONSHIP, 85 149 303 315 STYRENE, 180 316 STYRENE COPOLYMER, 8 33 71 113 316 STYRENE-ISOPRENE COPOLYMER, 178 STYRENE-METHYL METHACRYLATE COPOLYMER, 316 SULFENAMIDE, 136 168 SULFONHYDRAZIDE, 248 SULFUR, 136 169 SULFUR VULCANISATION, 169 SUN VISOR, 250 SUPERCRITICAL FLUID, 56 SUPERCRITICAL GAS, 21 245 SUPERCRITICAL SOLUTION, 134 SUPERSATURATION, 314 344 SURFACE ACTIVE AGENT, 92 199 SURFACE AREA, 169 245 314 SURFACE CHARGE, 427 SURFACE DENSITY, 246 SURFACE EXPANSION, 343 SURFACE FINISH, 119 169 179 263 311 406 SURFACE FREE ENERGY, 6

© Copyright 2004 Rapra Technology Limited

SURFACE PROPERTIES, 87 97 228 271 SURFACE RESISTIVITY, 427 SURFACE STRUCTURE, 271 SURFACE TENSION, 169 262 282 314 344 SURFACE TREATMENT, 262 318 343 SURFACE VEIL, 246 SURFACTANT, 92 199 SURFBOARD, 318 SURGICAL APPLICATION, 52 111 447 454 SWELLING, 11 SWELLING RATIO, 49 SYNDIOTACTIC, 77 SYNERGISM, 168 169 SYNTACTIC FOAM, 89 127 SYNTHESIS, 93 189 190 440 SYNTHETIC RUBBER, 143 149

T TABLEWARE, 446 TACKIFIER, 150 351 TAGUCHI CONCEPT, 94 TALC, 2 75 107 117 207 271 276 344 TANDEM EXTRUDER, 48 69 74 378 402 TANDEM EXTRUSION, 24 74 303 378 401 TEAR RESISTANCE, 70 76 83 184 TEAR STRENGTH, 16 50 53 70 76 83 128 148 184 261 297 341 TELECOMMUNICATIONS APPLICATION, 46 377 378 385 TELEVISION, 91 378 TEMPERATURE CONTROL, 62 73 85 144 194 260 312 440 TEMPERATURE DEPENDENCE, 19 34 35 55 75 78 83 119 127 142 168 169 210 314 TEMPERATURE DISTRIBUTION, 168 345 359 TEMPERATURE FLUCTUATION, 164 TEMPERATURE PROFILE, 168 315 359 TEMPERATURE RANGE, 311 TEMPERATURE RESISTANCE, 242 TEMPERATURE SENSITIVITY, 297 359 TENSILE MODULUS, 85 211 276 280

131

Subject Index

TENSILE PROPERTIES, 5 11 13 16 18 40 50 53 61 77 84 85 87 101 105 119 128 139 149 160 166 167 168 186 206 211 215 225 246 261 262 271 276 278 280 285 317 341 383 418 TENSILE STRENGTH, 11 13 16 18 40 50 53 77 84 85 87 105 128 160 168 186 246 261 262 271 276 280 281 291 296 297 303 341 368 374 TENSILE STRESS, 206 271 296 TENSIOMETRY, 262 TENSION, 393 TERNARY SYSTEM, 134 TERPOLYMER, 183 TESTING, 22 25 30 38 54 67 89 184 193 195 243 270 313 339 345 375 377 393 396 399 400 401 404 412 417 439 442 TETRAFLUOROETHANE, 328 330 TETRAFLUOROETHYLENE POLYMER, 419 TETRAHYDROFURAN, 310 TETRALIN, 416 THERMAL AGEING, 299 THERMAL ANALYSIS, 24 87 101 135 145 152 160 227 310 315 316 377 THERMAL CONDUCTIVITY, 39 57 61 67 80 115 151 178 192 194 238 246 261 262 270 279 291 299 314 359 375 403 434 THERMAL CYCLING, 296 THERMAL DECOMPOSITION, 212 334 361 THERMAL DEGRADATION, 135 253 316 THERMAL DIFFUSIVITY, 314 359 THERMAL EXPANSION, 39 174 178 206 210 238 271 285 305 393 THERMAL HISTORY, 20 315 THERMAL INSULATION, 4 30 39 72 91 111 160 164 165 181 194 244 260 262 263 289 299 302 311 345 352 388 390 403 404 422 431 434 442 451 453 THERMAL PROPERTIES, 5 8 19 32 34 44 57 61 67 79 85 89 101 115 131 143 174 178 194 210 238 245 246 262 270 271 273 299 314 315 316 339 344 345 359 368 393 434 441 442 THERMAL RADIATION, 151 THERMAL RESISTANCE, 414

132

THERMAL RESISTIVITY, 299 THERMAL SHRINKAGE, 76 370 THERMAL STABILITY, 76 85 120 139 148 163 186 189 190 195 246 249 260 300 311 355 361 368 381 388 390 391 393 408 414 424 446 THERMAL TRANSITION, 131 THERMODYNAMIC STABILITY, 273 288 THERMOFORMABILITY, 80 85 194 244 287 THERMOFORMING, 38 54 63 72 85 101 104 111 144 194 195 242 257 261 296 303 311 350 368 370 454 THERMOGRAM, 101 315 377 THERMOGRAVIMETRIC ANALYSIS, 24 90 135 152 198 226 316 441 THERMOPLASTIC ELASTOMER, 17 126 127 209 212 229 312 334 384 447 THERMOSET, 4 37 73 96 97 111 112 133 141 155 165 187 197 221 235 246 261 262 296 297 299 319 333 363 375 389 414 425 431 438 THIOPHOSPHATE, 168 TITANIUM DIOXIDE, 101 TOLUENE, 305 316 344 TOLUENESULFONYL HYDRAZIDE, 169 TORQUE, 168 TOUGHNESS, 4 120 175 180 183 189 190 242 300 336 346 349 361 408 413 TOXICITY, 196 248 TOYS, 239 TRANSMISSION ELECTRON MICROSCOPY, 5 21 72 151 210 224 TRANSMISSION OPTICAL MICROSCOPY, 315 TRANSPORT APPLICATION, 309 TRANSPORT INDUSTRY, 426 TRANSPORT PROPERTIES, 380 TRIALLYLCYANURATE, 49 65 TRIAZINE THIOL, 293 TRIAZOLE, 86 TRIFLUOROETHANE, 328 330 TRIMETHYLOLPROPANE TRIMETHACRYLATE, 49 TWIN-SCREW EXTRUDER, 123 170 217 233 311 314 344 359 TWO-ROLL MILL, 14 TWO-STAGE COPOLYMERISATION, 114

U UNDERWATER APPLICATION, 4 455 UNIAXIAL COMPRESSION, 213 UNSATURATED POLYESTER, 246 URAZOLE, 385 UREA, 86 136 UV RESISTANCE, 195

V VACUUM FLASK, 262 VACUUM FORMING, 3 194 422 VACUUM MOULD, 390 VAPOUR BARRIER, 158 VAPOUR PHASE, 344 VAPOUR PRESSURE, 194 344 VAPOUR TRANSMISSION, 261 VAPOURISATION, 316 VARIABLE PRESSURE FORMING, 92 VEHICLE BONNET, 438 VEHICLE BOOT, 322 VEHICLE DOOR, 322 VEHICLE INTERIOR, 302 VEHICLE ROOF, 221 VEHICLE SEAT, 91 379 VEHICLE SHELL, 22 248 322 VEHICLE TRIM, 177 292 388 395 451 VIBRATION DAMPER, 72 451 VIBRATION DAMPING, 175 180 181 195 248 VIBRATIONAL SPECTROSCOPY, 255 VINYL ACETATE-ETHYLENE COPOLYMER, 5 76 143 155 VINYL COPOLYMER, 124 247 VINYL ESTER COPOLYMER, 305 337 VINYL PHOSPHONATE, 374 VISCOELASTIC PROPERTIES, 8 55 82 89 99 116 205 236 243 254 259 266 289 314 325 359 400 419 VISCOSITY, 5 7 14 15 18 36 47 53 66 69 70 101 114 168 169 170 171 176 194 198 209 212 226 246 262 273 283 287 303 314 344 359 374 387 396 401 402 VOID RATIO, 12 VOID VOLUME, 380 VOLATILITY, 139 207 344 VOLUME CHANGE, 26 262 380 384 404 VOLUME CONTRACTION, 380

© Copyright 2004 Rapra Technology Limited

Subject Index

VOLUME FRACTION, 40 359 VOLUME RESISTIVITY, 261 VULCANISATE, 43 55 128 341 VULCANISATION, 9 14 168 169 293 384 VULCANISATION TIME, 9 62 73 83 141 VULCANISING AGENT, 136

W WALL PANEL, 430 WALL THICKNESS, 63 85 111 194 256 259 289 314 345 365 WALLPAPER, 305 WARPAGE, 85 87 119 160 227 WASTE, 115 246 368 WASTE RECOVERY, 92 WASTE WATER, 389 WATER, 11 139 185 235 262 265 WATER ABSORPTION, 11 14 248 261 279 291 368 403 427 448 WATER BLOWN, 262 WATER CONTENT, 139 WATER COOLING, 194 WATER HEATER, 262 WATER PIPE, 403 434 WATER RESISTANCE, 139 165 WATER SWELLABLE, 11 WATER TREATMENT, 389 WATER VAPOUR PERMEABILITY, 434 WATER VAPOUR TRANSMISSION, 261 WAX, 147 150 271 WEAR RESISTANCE, 62 83 141 179 208 WEATHER STRIPPING, 169 WEATHERING, 293 WEIGHT AVERAGE MOLECULAR WEIGHT, 124 209 WEIGHT RATIO, 136 247 273 WEIGHT REDUCTION, 3 13 72 92 164 194 195 244 260 302 311 312 410 WELDING, 323 368 WET SUIT, 293 WETTABILITY, 262 WETTING, 296 WIDE ANGLE X-RAY SCATTERING, 307 WILHELMY PLATE, 262 WIRE COVERING, 390 WOOD FIBRE, 12 74 WOOD FIBRE-REINFORCED PLASTIC, 24 74 WOOD FINISH, 158

WOOD FLOUR, 10 WOOD REPLACEMENT, 165 WOUND DRESSING, 150 WOVEN FABRIC, 277

X X-RAY DIFFRACTION, 45 101 255 X-RAY SCATTERING, 45 101 255 XYLENE, 310 416

Y YELLOWING, 228 YIELD POINT, 271 YIELD STRENGTH, 273 276 YIELD STRESS, 254 266 313 YOUNG’S MODULUS, 1 40 61 100 101 206 213 225 243 368

Z ZERO SHEAR VISCOSITY, 198 ZIEGLER-NATTA CATALYST, 249 ZINC CARBAMATE, 136 ZINC DICYANATODIAMINE, 169 ZINC OXIDE, 51 86 117 118 168 169 258 341 342 347 ZINC SALT, 169 ZINC STEARATE, 117

© Copyright 2004 Rapra Technology Limited

133

Subject Index

134

© Copyright 2004 Rapra Technology Limited

Company Index

Company Index A AACHEN,INSTITUT FUR KUNSTSTOFFVERARBEITUNG, 75 AALBORG,UNIVERSITY, 89 AIROFOAM AG, 338 AKRON,UNIVERSITY, 384 ALCATEL-CABLERIE SENEFFOISE, 378 ALGERIAN INSTITUTE OF PETROLEUM, 441 ALVEO AG, 447 AMB SRL, 101 AMERICAN INGREDIENTS CO., 147 AMERICAN TRADING & PRODUCTION CORP., 234 AMETEK CORP.,MICROFOAM DIV., 409 AMOCO CHEMICALS CORP., 445 AMOCO CORP., 340 AMOCO FOAM PRODUCTS CO., 445 API SPA, 179 APPLIED EXTRUSION TECHNOLOGIES INC., 429 ARCO CHEMICAL CO., 428 ARMSTRONG WORLD INDUSTRIES INC., 86 ARPECHIM SA, 157 ASAHI CHEMICAL CO.LTD., 448 ASAHI KASEI KOGYO KK, 289 ASTRO-VALCOUR INC., 371 372 AT & T BELL LABORATORIES, 377 385 AT PLASTICS INC., 267 AUSIMONT SPA, 201 298

B BARCELONA,ESCOLA TECNICA SUPERIOR D’ENGINYERS INDUSTRIALS, 153 BASF AG, 164 302 368 399 412 415 424 BASF CORP., 265 279 297 301 BASF ESPANOLA SA, 368 BASF PLC, 324 399 BASF UK LTD., 322 BATTENFELD EXTRUSIONSTECHNIK

GMBH, 431 BATTENFELD GLOUCESTER ENGINEERING CO.INC., 106 BAYER AG, 111 169 228 BECTON,DICKINSON & CO., 223 BEIJING,NORMAL UNIVERSITY, 285 BELFAST,QUEEN’S UNIVERSITY, 34 54 85 105 135 BERSTORFF H.,MASCHINENBAU GMBH, 229 BERSTORFF H.,MASCHINENFABRIK GMBH, 246 BFT PLASTICS, 263 BIRMINGHAM,UNIVERSITY, 33 167 213 254 266 270 295 313 325 400 419 BOEHRINGER, 135 BOGOTA,UNIVERSIDAD DE COLOMBIA, 153 BOREALIS, 4 26 31 34 42 48 78 170 173 177 192 276 280 BP CHEMICALS BELGIUM SA, 378 BP CHEMICALS LTD., 378 383 394 BRITISH BOARD OF AGREMENT, 403 BROCK USA, 37 41 BRUCKNER MASCHINENBAU GMBH, 59 BRUNEL UNIVERSITY, 326 BULGARIAN ACADEMY OF SCIENCES, 44 45 145 218 219 269 418 421 BXL PLASTICS LTD., 419 432 437 444 447 450

UNIVERSITY, 16 84 CINCINNATI,UNIVERSITY, 245 363 CLARKSON UNIVERSITY, 288 329 359 COLOMBIA,UNIVERSITY, 57 61 94 143 151 174 CONVENIENCE FOOD SYSTEMS BV, 244 COURTAULDS ADVANCED MATERIALS, 419 CPL HARTMEYER, 389 CREME ART CORP., 362 CROMPTON/UNIROYAL CHEMICAL, 9 CRYOVAC INC., 104 CSI, 317

C

E

CAIRO,UNIVERSITY, 40 CANADA,NATIONAL RESEARCH COUNCIL, 7 17 36 117 222 272 CANNON GROUP, 111 CEBO (UK) LTD., 455 CERSIM, 2 CHANG GUNG,UNIVERSITY, 87 119 160 227 CHUNGBUK,NATIONAL

EARTH & OCEAN SPORTS INC., 343 ELECTROLUX AB, 111 EQUISTAR CHEMICALS LP, 130 EXXON CHEMICAL CO., 248 454 EXXON CHEMICAL PATENTS INC., 93 EXXON RESEARCH & ENGINEERING CO., 134

© Copyright 2004 Rapra Technology Limited

D DAIMLERCHRYSLER CORP., 22 DOW CHEMICAL CO., 22 30 38 64 72 76 77 113 116 131 154 162 175 180 182 220 256 274 296 303 319 321 327 328 330 333 335 336 346 349 357 358 367 382 426 DOW CORNING CORP., 146 DOW DEUTSCHLAND INC., 131 154 251 268 DOW EUROPE SA, 392 DOW PLASTICS, 410 DSM NV, 209 DSM RESEARCH, 255 307 DU PONT DOW ELASTOMERS, 50 DUNLOP SLAZENGER INTERNATIONAL LTD., 437 DUPONT DE NEMOURS E.I.,& CO.INC., 240 351 DUPONT ELASTOMERS, 128

135

Company Index

F FAGERDALA WORLD FOAMS AB, 242 FERRO CORP., 292 FINA OIL & CHEMICAL, 445 FORD MOTOR CO., 322 FULLER H.B.,LICENSING & FINANCING INC., 150 FURUKAWA ELECTRIC CO.LTD., 446

G GAIKER, 246 GENERAL ELECTRIC PLASTICS, 445 GEORGIA INSTITUTE OF TECHNOLOGY, 440 442 GMP, 111 GOTTWALDOV,RESEARCH INST.FOR RUBBER & PLASTICS, 433 GRAND POLYMER CO.LTD., 140 GRAZ,UNIVERSITAT, 45 GREAT LAKES CHEMICAL CORP., 353 354

H HAPPICH GMBH, 250 HIMONT INC., 350 369 396 401 402 408 411 445 HITACHI CHEMICAL CO., 405 HOBOKEN,POLYMER PROCESSING INSTITUTE, 276 HOECHST AG, 420 422 HS CORP., 208

I IAV INGENIEURGES.FUER AGGR.& VERKEHRS.MBH, 438 ICPE SA, 157 IDEMITSU PETROCHEMICAL CO.LTD., 96 IKV, 168 171 IMCOA, 345 IMPERIAL COLLEGE, 236 380 INDIAN INSTITUTE OF TECHNOLOGY, 43 50 53 55 128 341 INDUCEL LTDA, 318 INDUSTRIAL THERMO

136

POLYMERS LTD., 360 INSTITUT FUER CHEMIEFASERN, 246 INVESTMENT HOLDINGS GROUP LTD., 430 IOWA,UNIVERSITY, 286 ISTANBUL,TECHNICAL UNIVERSITY, 363 ITALPRODUCTS SRL, 144 194

J JAPAN ATOMIC ENERGY RESEARCH INSTITUTE, 374 427 JAPAN SYNTHETIC PAPER CO., 390 JILIN,UNIVERSITY, 11 JSP CORP., 102 125 159 188 211 247 290 331 332 366 386 398 407 414 JSP INTERNATIONAL, 161 195 366

K KANEKA CORP., 97 103 139 186 302 KANEKAGAFUCHI CHEMICAL INDUSTRY CO.LTD., 124 447 KAOHSIUNG,POLYTECHNIC INSTITUTE, 258 KING MONGKUT’S INSTITUTE OF TECHNOLOGY THONBURI, 166 KINGSTON,QUEEN’S UNIVERSITY, 5 KOREA,INSTITUTE OF FOOTWEAR & LEATHER TECHNOLOGY, 208 KRUEGER & PARTNER, 58 KYOTO,UNIVERSITY, 21 25 138

L LAVAL,UNIVERSITY, 2 18 LAWRENCE LIVERMORE NATIONAL LABORATORY, 416 LEHIGH,UNIVERSITY, 134 LOUISIANA,STATE UNIVERSITY, 134 LOWELL,UNIVERSITY, 277

M

MAIN GROUP, 62 73 MANCHESTER,UNIVERSITY, 14 49 65 206 304 MANKIEWICZ GEBR.& CO., 323 MARYLAND,UNIVERSITY, 240 MASSACHUSETTS,UNIVERSITY, 19 127 245 MICHIGAN,STATE UNIVERSITY, 10 12 320 MICHIGAN,TECHNOLOGICAL UNIVERSITY, 10 MICHIGAN,UNIVERSITY, 404 417 MICROCELL TECHNOLOGY CONSULTANTS LTD., 451 MIDDLE EAST,TECHNICAL UNIVERSITY, 310 MILLENNIUM PETROCHEMICALS INC., 187 MINNESOTA,UNIVERSITY, 52 MITSUBISHI PETROCHEMICAL CO.LTD., 388 395 397 MITSUI CHEMICALS INC., 148 MITSUI PETROCHEMICAL INDUSTRIES LTD., 221 293 364 MOBIL CHEMICAL CO., 283 445 MOBIL OIL CORP., 156 MONSANTO CO., 384 MONTELL NORTH AMERICA INC., 183 257 317 MONTELL POLYOLEFINS CO., 230 MOSCOW,INSTITUTE OF FINE CHEMICAL TECHNOLOGY, 203

N NAGOYA MUNICIPAL INDUSTRIAL RESEARCH INSTITUTE, 60 99 243 NAPLES,UNIVERSITY, 246 NAPOLI,UNIVERSITA FEDERICO II, 82 NEW JERSEY,INSTITUTE OF TECHNOLOGY, 28 29 79 NIDA-CORE CORP., 309 NIPPON UNICAR CO.LTD., 107 NMC-KENMORE (UK) LTD., 403 NORTH CAROLINA,STATE UNIVERSITY, 223 NOVA CHEMICALS, 27 69 70 231

M & G RICERCHE SPA, 246

© Copyright 2004 Rapra Technology Limited

Company Index

O OAK RIDGE NATIONAL LABORATORY, 299 375 OMAM SPA, 287

P PEGUFORM GMBH, 195 PENNSYLVANIA,STATE UNIVERSITY, 67 PLASTEDIL SA, 430 PLASTIC DESIGN SOLUTIONS UK, 322 POLYMER PROCESSING INSTITUTE, 280 339 POLYMER-TEC GMBH, 3 PRAGUE,MATERIALS RESEARCH INSTITUTE, 449 PRINCE OF SONGKLA UNIVERSITY, 14 PROTECTION PACKAGING LTD., 91 98

Q QUERETARO,UNIVERSIDAD AUTONOMA, 57 61

R RAPRA TECHNOLOGY LTD., 92 233 REEDY INTERNATIONAL CORP., 144 194 REIFENHAUSER GMBH, 80 311 RESEARCH DEVELOPMENT CORP., 376 RHEOMETRIC SCIENTIFIC INC., 222 RUSSIAN ACADEMY OF SCIENCES, 115

S SAINS MALAYSIA,UNIVERSITY, 49 65 SANWA KAKO CO., 243 374 379 427 SEALED AIR CORP., 1 47 71 122 123 129 142 172 181 202 217 278 281 294 314 342 344 347 359 387 SEALED AIR LTD., 214 SEKISUI ALVEO BV, 174 210 238 SEKISUI CHEMICAL, 165 361

SEKISUI KASEIHIN KOGYO KK, 370 381 453 SEKISUI PLASTICS CO.LTD., 391 413 SENTINEL PRODUCTS CORP., 120 189 190 196 197 200 237 292 300 SHELL RESEARCH & TECHNOLOGY CENTRE, 149 SHERWOOD TECHNOLOGIES INC., 23 SHIRAM INSTITUTE FOR INDUSTRIAL RESEARCH, 184 SICOMIN, 425 SIEBE ENGINEERING, 365 SIKA CORP., 351 SINTEF, 170 SISTEMA COMPOSITI SPA, 246 SMEG, 111 SOFIA,HIGHER CHEMICOTECHNOLOGICAL INSTITUTE, 406 SOFIA,RESEARCH CENTER FOR CONSTRUCTION POLYMERS, 439 SOLVAY POLYOLEFINS EUROPE-BELGIUM SA, 137 SOUTH CHINA,UNIVERSITY OF TECHNOLOGY, 6 STEPAN CO., 262 STEVENS INSTITUTE OF TECHNOLOGY, 339 STUTTGART,UNIVERSITY, 216 SUEZ CANAL,UNIVERSITY, 40 SUMITOMO CHEMICAL CO.LTD., 110 114 212 252 264 305 334 373

T TAIWAN,NATIONAL CHUNG CHENG UNIVERSITY, 8 TAMPERE,UNIVERSITY OF TECHNOLOGY, 356 TENNECO PROTECTIVE PACKAGING INC., 109 133 158 185 205 235 TENNESSEE,TECHNOLOGICAL UNIVERSITY, 52 TEXAS A & M UNIVERSITY, 436 TEXAS,ARLINGTON UNIVERSITY, 345 TONEN CHEMICAL CORP., 355 TORONTO,UNIVERSITY, 15 24 26 35 42 48 51 68 74 78 81 118 152 191 198 204 207 215 226 273 275 282 284 315

© Copyright 2004 Rapra Technology Limited

TOSOH CORP., 66 100 TOYODA GOSEI CO.LTD., 136 TOYOTA CENTRAL R & D LABORATORIES INC., 21 TOYOTA MOTOR CORP., 126 TOYOTA TECHNOLOGICAL INSTITUTE, 21 TREXEL INC., 13 56 63 TRIESTE,UNIVERSITY, 101 TWENTE,UNIVERSITY, 255 307

U UDMURT,SCIENTIFIC CENTRE, 115 UMIST, 14 49 65 206 225 253 304 306 308 UNIROYAL CHEMICAL CO.INC., 232 241 URETHANE PRODUCTS INTERNATIONAL, 141 US,NATIONAL ROOFING CONTRACTORS ASSOCIATION, 299 USG RESEARCH CENTER, 272

V VALLADOLID,UNIVERSIDAD, 20 39 57 61 94 132 151 153 174 178 210 238 259 VTT CHEMICAL TECHNOLOGY, 193

W WATERLOO,UNIVERSITY, 83 WEDTECH INC., 176 191 198 226 WELLA AG, 95 WIRE & CABLE TECHNICAL SERVICE, 46 WOODBRIDGE FOAM CORP., 297 WORCESTER,POLYTECHNIC INSTITUTE, 316

Y YALE,UNIVERSITY, 32 88 YMOS, 248 YOUNGBO CHEMICAL CO.LTD., 84

Z ZOTEFOAMS, 39 163 224 261 348

137

Company Index

138

© Copyright 2004 Rapra Technology Limited

DOCUMENTS DIRECT (Document Delivery Service) The Polymer Library (www.polymerlibrary.com) is the world’s most comprehensive collection of information on the rubber, plastics, composites and adhesives industries. The fully searchable database covers approximately 500 regular journals as well as conference proceedings, reports, books, company brochures and data sheets. Almost all the articles selected for the database can be ordered in full text through our document delivery department. Non-patent requests are usually despatched within 24 hours of receipt (Monday to Friday). ●

We have a large collection of literature directly related to the industries we serve and can offer a personal service with minimal bureaucracy, based on detailed knowledge of our stock.

●

Many of the documents held at Rapra are not available via other services. This is particularly the case for our extensive and unique collection of company literature and data sheets.

●

We offer a fast turnaround service (within one working day) combined with a range of delivery options. Some full text documents are available as PDF files which can be downloaded immediately

SPEED OF DELIVERY Non-patent documents are despatched from Rapra within 24 hours of receipt (Monday - Friday) of request using first class mail within the UK, and airmail for the rest of the world. If you request e-mail or fax service, delivery will be within hours anywhere in the world.

HOW TO ORDER Orders can be made by post, fax, telephone, e-mail, on-line via the website database (http://www.polymerlibrary.com), or through an online host. When ordering please include your full company details and which documents you require, quoting one of the following: 1. Accession Number or Copyquest number or, 2. Full Bibliographic Details Please include which payment method you wish to use and how you wish to receive the article (i.e. e-mail, post, fax, etc.) Documents can be ordered from Rapra online using the appropriate command of your online host. In this case we will issue you with an invoice and statement every three months. For further information, please see www.rapra.net/absdocs/copyquest.htm or contact Sheila Cheese or Jackie McCarthy on +44 (0)1939 250383 or e-mail [email protected].

PLEASE TURN OVER FOR PAYMENT METHOD OPTIONS AND ORDER FORM

CREDIT CARD PAYMENTS This is preferable for people who only intend to use our service occasionally. The prices are per copy inclusive of postage and packaging if appropriate. Pre-payment is required by Credit Card payment. Delivery Method

Price

E-mail, Ariel, Fax, First Class / Airmail Post

£10 / Approx. US$15 or €17 (UK & Overseas) + VAT

PDF files

Prices – Please refer to online order form for details (these may vary – each publisher sets price)

ANNUAL DEPOSIT ACCOUNTS A more cost effective way to use our service is to open an annual deposit account. (Web subscribers can use their web subscription for both web access and document delivery) The minimum amount required to open an account is £200 / Approx. US$290 or €330 (UK & Overseas) Delivery Method

Price

E-mail, Ariel, Fax, First Class / Airmail Post

Documents are only priced at £7 / Approx. US$10 or €12 per item

PDF files

Prices – Please refer to online order form for details (these may vary – each publisher sets price)

Please Note: Any money remaining in an annual deposit account after 12 months is void. Patents are charged at a standard price of £10 / Approx. US$15 or €17.

ORDER FORM ❑ ❑

I would like to open/renew a deposit account for the following amount ___________________________________ I would like to order the following documents _______________________________________________________ _____________________________________________________________________________________________

PAYMENT Name: ____________________________________________________ Company: _________________________________________________ Address: __________________________________________________ _________________________________________________________ _________________________________________________________ Postcode: ______________________ Country: __________________ Telephone: _____________________ Fax: ______________________

❑ Remittance enclosed

(use only for opening or renewing annual deposit accounts)

(If paying by cheque, please make payable to Rapra Technology Ltd. in £ Sterling/US$/Euros via UK banks only or make payment direct to Account No: 05625025, Sortcode: 55-50-05, National Westminster Bank Plc, 8 Mardol Head, Shrewsbury, Shropshire, SY1 1HE, UK)

❑ Please invoice my company (use only for opening or renewing annual deposit accounts)

❑ Please deduct from my annual deposit account (use this option when ordering documents if you already have a deposit account)

IMPORTANT - Value Added Tax (VAT) The above prices do not include VAT. Customers in EU member countries may be liable to pay VAT if their Registration Number is not supplied. Please enter your EU Registration Number (VAT - BTW - IVA - TVA - MWST - MOMS - FPA) below:

VAT Number: Rapra Technology Limited Shawbury, Shrewsbury, Shropshire SY4 4NR, United Kingdom Tel. +44 (0)1939 250383 Fax: +44 (0)1939 251118 E-mail: [email protected]

Account Number _______________________________________

❑ Please charge my credit card American Express / Visa / Mastercard (delete as appropriate) Card Number:

Signature: ______________________ Exp. date: ______________