Textile Application of the Color Sensitivity of a Dye Mixture

TECHNICAL REPORT ON TEXTILE APPLICATION OF THE COLOR SENSITIVITY OF DYE MIXTURES

TEXTILE LABORATORY APPLIED CHEMISTRY RESEARCH CENTRE.

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TECHNICAL REPORT ON TEXTILE APPLICATION OF THE COLOR SENSITIVITY OF DYE MIXTURES

Prepared By

Javaid Mughal, Mansoor Iqbal and Muhammad Naeem (A Team of Textile Scientists at PCSIR Lab Complex Karachi)

E-mail: [email protected] [email protected] [email protected]

TEXTILE LABORATORY APPLIED CHEMISTRY RESEARCH CENTRE 2

INTRODUCTION: Cotton is the backbone of the world’s textile trade. It has many qualities and countless end uses, which make it one of the most abundantly, used textile fibres in the world. It is a seed hair of plant of genus gossypium, the purest form of cellulose found in nature. However, cotton is one of the most problematic fibres as far as its general wet processing or dyeing is concerned. Quite frequently, the problems in dyed cotton materials are not due to the actual dyeing process but due to some latent defects introduced from previous production and processing stages. Often, the root-cause of a problem in the dyed material can be traced as far back as to the cotton field. The dyeability variations are cotton obtained from different sources. It has been suggested that the substrate should be obtained from a single source, wherever possible, in order to keep the dyeability. Variations than other, those dyes should be selected for dyeing which are less sensitive to dyeability variation. In dyeing, if resultant shade for a dye mixture passes the quality examination after its first dyeing, the product is called a right-first-time product. The process producing the right-first-time product is thus called a right-first-time process: one that is economical because it consumes the least energy, labor, and time etc. To produce a rightfirst-time product, process control is essential for dyeing and, to enable this, many modern dyeing control systems have been developed. Unfortunately, errors in the dyeing operation will still sometimes occur. Therefore employing a low-sensitivity recipe in dyeing may be an alternative approach. Should dyeing errors occur, the less sensitive the recipe is to such errors, the more chance there is that the resultant shade will successful. Target Shade Dye Brand Sensitivity Normal Concentration Sensitivity Modified Dye Total Sensitivity

Temperature Sensitivity Time Sensitivity Auxiliaries Sensitivity Liquor Ratio Sensitivity

Temperature Change database Time Change database Auxiliaries Change database Liquor Ratio Change database

Figure 1: Procedure for predicting colour sensitivity.

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The research that has been done in this field has been limited to establishing and applying a method of predicting the colour sensitivity of a matching recipe. This research help us the selection of dyes in a mixture recipe for dyeing. However, in practice, the effectiveness of the recipe solution by the concentration sensitivity could be only marginal and other parameters might be more important to the recipe performance than an error in the dye concentration. Therefore it is important to consider colour sensitivity in its widest possible context. Dye sensitivity is collection of various functional parameters. If we want to measure reactive dye sensitivity, we must know the conditions, type of dyes added, nature of dyeing (PDC, PB, Exhaust), what auxiliaries are added, time, temperature, liquor ratio, fabric etc. so many factors affected on the dyes sensitivity.

Sensitivity measuring terminology: Sensitivity has two major parts first, part is to do the changes in dyeing parameters chemically or mechanically, in second part is to measure the sensitivity by colour measuring instruments in the terms of K/S, CIE Lab, %E, %F, Build-up properties, Strength comparison or by fastness properties. There are many diverse reasons for measuring colour, and instrument requirements vary widely with each application. Relative measurements at a single location are obviously less stringent than absolute measurements that must provide comparable data when measured at different locations. Spectrophotometers, colorimeters, and instruments that combine various features of both are available to meet most of these requirements. Although simple, low-cost colorimeters and spectrophotometers are usually adequate for relative colour measurements on specific problems, the more complex and costly double-beam recording spectrophotometers, interfaced to a computer, is the preferred instrument system for the general analysis of synthetic dyes. Colour is three dimensional, a property that is apparent in various ways. Colour atlases arrange colours using three scales (Hue, value and chroma) in the case of the Munsell system. To accurate specification of object colours and colour differences, CIE recommended threedimensional uniform colour spaces-CIE Lab and CIE LUV in 1976. Since the equations are long, they are omitted here. These are called the CIE 1976 (L* a* b*) colour space or CIE Lab colour space, and the other, CIE 1976 (L* U* V*) colour space or CIE LUV colour space, and have similar structures as the Munsell colour solid. In imaging applications, CIE Lab space is commonly used. In CIE Lab space, L* shows the lightness, and (a* b*) the colour as shown in fig, 1

Figure 1. CIE Lab. 4

The coordinate (L*, a*, b*) is calculated from the (x, y, z) of the given light stimulus and (Xn, Yn, Zn) of the white point. Therefore, the CIE Lab space has a function of correcting for chromatic adaptation to the white point, and is intended for object colour and displays. The colour difference in the CIE Lab space is calculated as the Euclidean distance between the points in this three-dimensional space, and is given by, ΔE*ab = [ (ΔL*)2 + (Δa*)2 + (Δb*)2

]1/2

This equation is called the CIE 1976 (L* a* b*) colour difference formula .The chroma C*ab and the hue angle hab are also calculated from (l * a* b*) by, C*ab = (a*2 Hab

= tan-1

+

b*2)1/2

(b*/a*)

The CIE LUV space is defined in a similar manner, and the coordinate (L*, U*, V*) is calculated from the Y and (u’, v’) of the given light stimulus and the white point. The colour difference, ΔE*ab is widely used; its chroma scale is known to be fairly nonlinear. For more accurate colour difference evaluations, CIE recommended an improved industrial colour difference formula in 1994-CIE 94 formula. The colour difference ΔE* is calculated from ΔL*, ΔC*ab and ΔH*ab of the CIE Lab formula. Another improved formula, the CMC colour difference formula, is mainly used in textile industry. Further improved colour difference formulas are being investigated by CIE. In CIE Lab, the selections of light sources are also available in the system. • An artificial day light source, D65. • A tungsten-filament sources. • A three-band fluorescent sources TL84. • A UV source (For enhancing fluorescent white)

Steps in the determination of a dyeing recipe: A recipe of dyes consists of one or many dyes, the quality of each dye (in the quantity of product that should be used at the beginning of the dyeing) and the application process. Recipe of dyes also indicates all the parameters of dyeing process, such as the temperature, time, liquor ratio, quantity of chemicals and auxiliaries. The determination of a dyeing recipe takes place in three main steps: First step: The first step consists of selection of the dyestuffs and of the dyeing process that may be used to calculate the recipes of dyes. Second step: The second step is the calculation of the recipes of dyes from the previously selected objects. This calculation is done from calibration range of dyes. A calibration range consists in dyeing an article, using a specific process and with several concentration of dyes. Computer provides 5

a mean of testing alternative dye combinations to find the optimum mixture that will minimum cost and /or color difference relative to the target shade. The number of recipes to be predicted rises very rapidly as the number of possible dyes is increased. Then, it is very important to eliminate as soon as possible, all the objects that will not permit the requirement to be fulfilled. Moreover, in the case of article made of several fibers, such as cotton/polyester articles, a recipe of dye has to be calculated for cotton fiber, and another one for the polyester fibers. Third step: In the third step “best” calculated recipe of dyes is selected. The complete dyeing recipe is determined. Then a sample is dyed and if the dyed sample has the desired color and if the client requirements are fulfilled, this dyeing recipe is accepted for production. If the desired color is not obtained, then the recipe of the dyes is to be modified (i.e. the concentration of each dyes), until the color difference between target and the match sample is negligible. Finally if the requirements are not achieved by the dyeing recipe (for instance the washing fatness is too low), then the dyer must choose another recipe of dyes. Whenever there is some difficulties with all the calculated recipes of dyes, it means that the textile processing mills can not fulfill the client specifications due to dyes or process. At present, there are tools that permit the recipe of dyes to be calculated by using the Kubelka – Munck’s relationship or K / S values.

Fig. Process of determination of a dyeing recipe. 6

COLOR SENSITIVITY OF DYE MIXTURE: Formulating colorant recipes to match target colours is not an easy task. Manual color prediction often uses a trial and error method, for which the experience of the colourist is essential. The majority of color matching also required color to be matched not only under daylight, but also under other artificial light sources such as cool white fluorescent (CWF), TL84, D65, etc. a previous recipe archive is very useful for manual color matching. A colourist would firstly search the previous recipe archive to find out the closest colour matching target or standard and then make sure adjustment to the recipe if the recipe color is not the exact match to the target. However this trial and error process is lengthy and arduous even for a professional colourist. Computer color matching is an alternative method. Alderson first discovered the commercial application of computer color recipe formulation in textile in 1961.the computer color matching becomes a necessity for a modern dye house to install a computer colorant formulation system. Color matching to a target shade depends not only on the formulation system but also on the: -

Accuracy of the recipe preparation. The repeatability of the dyeing process. The color measurement process.

There is a need of quality control at each step in the coloration and the measuring process. The core of the formulation system is based on the theory developed by Kubelka & Munk known as Kubelka – Munk theory. Recipe correction: After recipe formulation, a new color sample can be produced according to the colorant concentration suggested. Because of the influence of the various variables in the dyeing process, the produced sample may not be acceptable and a recipe correction process may be needed. Laboratory correction: Laboratory correction gives a fresh recipe according to what was obtained by previous dyeing. The new concentration calculation as follows: Cn = Cp X Cu / Cb

(1 ).

Cn = Cp + Cu - Cb

(2 ).

or

Where Cn = corrected recipe. Cp = predicted recipe for target. 7

Cu = recipe used in dyeing equal to Cp . Cb = recipe back – predicted for the batch dyeing results. Correction method in equation 1 is called weighted or ratio correction and that is given in equation 2 is called additive correction. Production correction: Production correction predicts the additional amount of dyes to be added to the dyeing bath:

Cadd = Cn -

Cu

(3 ).

Where Cn is calculated according to the laboratory correction via either weighted or additive methods. There is no beed – off included in the calculation. It may be added if bleeding is a problem. If a batch is already too dark compared with standard this correction for exhaust dyeing will fail, mean that the absorbed dyes should be stripped before correction. for continuous dyeing diluents need to be added to dilute the dye liquor,. However for a slight dark color, the production correction for exhaustion dyeing should correct huge difference and try to reduce the overall color difference.

Visual assessment of colour: For the visual determination of the specification of an unknown specimen, a colour atlas is viewed alongside the specimen under prescribed conditions. An approximate specification of the specimen is given by the denotation of the chip juded closest to its colour. The human visual system can distinguish several million colour, however, where as most colour atlases contain at best a few thousands chips. Even the most comprehensive systematic sampling of colour space yet produced, whilst the human visual system is an excellent null detector (being very capable of assessing whether or not colours match), it is not good at estimating the relative magnitude of differences in colour. If several assessors interpolate to arrive at specification their reports usually differ, after significantly, and even the some assessor assessing on different occasions usually gives a variety of specifications. In an experiment, the ICI colour atlas coordinates of six specimens were assessed, to the nearest chip, by five experienced assessors under identical conditions on each of six occasions, not one assessor chose the same three coordinates for any specimen on all occasions, and one assessor did not choose the same three coordinates, for three of the specimens, on any occasion. Lack of correlation between interpolations is one of the principle problems of visual methods of specifying colour. Nevertheless colour atlases continue to be used because it is necessary in same applications, and desirable in others, to have available a collection of chips systematically sampling colour space.

Variables in the analytical method: Specific details concerning sampling, solvents, weights, volumes, and special techniques to cope with solution and measurement idiosyncrasies must be established individually for each species of colorant. Although several of these problems are minimized simply by good analytical technique, some problems are unique to the spectrophotometeric measurement of 8

colorants in solution. A few of the pitfalls encountered in solution coloristics are discussed below.

Solution variables: Solution variables may have a pronounced effect on colour measurement. Each effect should be considered from its dual aspect; by measuring the material the effect may be studied, and by controlling the effect the material may be determined. In developing an analytical method each new colorant should be screened to determine its behaviour towards each of the solution variables. If a solution variable is found to have a significant effect on the coloristics, conditions must be changed to maximize analytical precision. Shade and strength parameters may both vary with solution conditions, one parameter may change without any significant effect upon the other.

Concentration effect: Variation in absorptivity with concentration represents non-conformance to beer’s law rather than a failure of the law. Beer’s law holds for single molecular or ionic species of the colorant being analysed. If aggregate molecules or ions are present in equilibrium, the equilibrium may shift with changes in the concentration and the system does not conform to Beer’s law. If the aggregate equilibrium is constant with changes in concentration, the system conforms. Conformance to Beer’s law is required to obtained reliable coloristics data. Non conformance is usually dealt with by narrowing the concentration range or by changing the solvent strength alone can be accurately determined in a non conforming system either measuring the absorbance at an isobestic point or by making appropriate corrections from a predetermined plot of absorbance versus concentration.

Temperature effect: At very low temperature the molecular vibrations of a colorant may be so restricted that the solution becomes colourless. At room temperature and higher, colour variation with temperature is usually attributed to isomerization, aggregation, or chemical reaction. Temperature effects on coloristics properties are either reversible or irreversible. A reversible effect during heating to dissolve the dye is unimportant because the original form is obtained after cooling. If an irreversible change occurs during heating for dissolution conditions can be changed to avoid the temperature effect. If temperature affects the dilute solution it should be thoroughly investigated to determine whether the change is reversible and at what temperature the changed occurs.

pH effect: The initial pH of the dyebath will be lower at the end of the dyeing by one half to whole unit, indicating that some alkali has been used up during dyeing. The cellulosic fibre is responsible for some of this reduction, while a smaller part is used by the dyestuff as it hydrolysis. The effect of pH, account must be taken of the internal pH of the fibre as well as the external pH of the solution. The internal pH is always lower than external pH of the solution. Since the decomposition reaction is entirely in the external solution, the higher external pH favors decomposition of the dye rather than reaction with the fiber. pH influences primarily the concentration of the cellusate site on the fibre. It also influences the hydroxyl ion concentration in the bath and in the fibre. Raising the pH value by 1 unit corresponds to a temperature rise of 20oc; the dyeing rate is best improved by raising the dyeing temperature 9

once a pH of 11-12 is reached. Further increased in pH will reduce the reaction rate as well as the efficiency of fixation. Different types of alkalis, such as caustic soda, soda ash, sodium silicate or a combination of these alkalis, are used in order to attain the required dyeing pH. The choice of alkali usually depends on the nature of dye. The colour of many dyes varies quite drastically with pH, and in most instances this behaviour is predictable from chemical structure. To provide reliable coloristics data for products that vary with pH, it is necessary to adjust the pH prior to measurement. Adjustment is made either by titration or by using a solvent buffered to a specific pH. For case of operation the buffered solvent is preferred, provided its buffering capacity is capable of suppressing pH variation from one sample to another.

Electrolyte effect: The addition of electrolyte results in an increase in the rate and extent of exhaustion, increase in dye aggregation and a decrease in diffusion. The electrolyte efficiency increases in the order: KCl
Irradiation effects: Colour change with exposure to light may be either reversible or irreversible. The reversible property is known as photochromism and the irreversible property is light fading.

Surfactant effect: Non-ionic surfactants are frequently added in small amounts to the analytical solvent as a dissolution aid; this may be specified in the procedure. However, if a surfactant is inadvertently introduced as a contaminant it may affect the spectral properties of the dye being analysed. It has also been reported that the presence of surfactants may enhance the sensitivity of a dye in solution to irradiation.

Ion effect: Many dyes are good chelating agents are evidenced from their structures and the extensive commercial use of metalized dyes. Thus it should be no surprise that dyes scavenge metal ions from solution and that the metal ions change the coloristics properties. This effect decreases the strength and change the shade. Some dyes are sensitive to electrolytes and changes with the concentration of ions in solution. Interfering ions present many problems in correlation solution coloristics with shade and strength determination in end use test. The effect of interfering ions can be minimized, and sometimes eliminated, by adding chelating agents, surfactants, or protective colloids to the colorant solution, however, it must be remembered that these measures are not being taken in the application tests.

Impurity analysis: Impurity is defined here as any undesirable colorant, or combination of colorants, that adversely affects the end use properties of a dye. If the impurity is identified as a single species and significant amounts of it are present, it can be quantitatively determined by analytical technique or by separation technique. 10

The methods of impurity measurement apply only when the level of impurity is significant large so that it can be seen to influence the profile of a spectral curve. It is also possible to have impurity present at such low concentration that they are not detectable by conventional analysis yet create problems in dyeing. If these impurities absorb in an area of low absorbance for the dye being measured their absorbance can be exaggerated by measuring a more concentrated solution (the stock solution is frequently used) in this particular area of the spectrum. The most convenient way with simple instrumentation is to determine the absorbance of sample and standard at specific wavelength and normalize for concentration, path length, and AI according to the following equation. I.I = Aλa BC AI Where I.I is the impurity index, A is the absorbance at wavelength a, b is the sample path length in centimetres; C is the dye concentration in grams per liter (as decimal fraction) of the sample being measured. I.I = f A1 (sample) - f A2 (standard).

Application to dyeing problems: Solution colourist can be as important to dye application, as it is to dye synthesis. It was recognized during early instrumental measurement of dyed fabric that the accuracy of color specification was limited more by the dyeing process than by the method of measuring. As a result, solution colorists in one form or another has been used to study all aspects of the dyeing process. Solution spectra are usually obtained when the dye is received. Although most solutions measurements are made to determine strength, other colorists criteria may also be used to determine acceptability. Before solution colorists can be used in this way it must be established that solution data correlate with application testing. Solution colorists is also used in controlling the dye bath. For proper controlling it is necessary for the solubility of the dye to be known, because poor solubility causes weak dyeings and/or specking. Solution colorists is often used in the maintanance of dye standards. Dye standards may change with time owing the hygroscopicity of powders, evaporation of liquids, or the general degradation of quality with time. Periodic color analysis of dye standards and comparision with data obtained from earlier analysis will indicate quality changes. Standard drift is not easily detected from routine analysis where samples are compared to standard in a relative sense.

Influence of Dye characteristics in reactive dyeing: The major dye variables that affect reactive dyeing are dye chemistry, substantivity, Reactivity, diffusion coefficient and substativity, each of these will be discussed below: Dye chemistry: Reactive dye has a wide variety in terms of their chemical structure. The two most important component of a reactive dye are the chromophour and the reactive group. The characteristics governed by the chromophour are color gamut, light fastness, chlorine / bleach fastness, solubility, affinity and diffusion. The chromophour of most of the reactive dyes are azo, anthraqnone, Pthalocynine. Azo dyes are dischargible, diazo dyes have the disadvantage of being much more sensitive to reduction and many of them are difficult to wash-off. Most of 11

them possess excellent fastness to light and to crease resistant finish, but they are not dischargeable. Pthalocynine dyes diffuses slowly and are difficult to wash off. Meta complex dyes containing copper possesses rather dull hues, but shows a high degree of fastness to light and to crease resistant finishes. There substantivity is fairy high 1:2 complexes diffuse relatively slowly. So a longer time is needed to wash out unfixed dye completely. The dye characteristics governed by reactive group are reactivity, dye-fiber bond stability, and efficiency of reaction with the fiber and affinity. Dyeing conditions, especially the alkali requirements and temperature as well as the use of salt also depends upon the type of reactive group. Dyes based on s-triazine do not have good fastness properties in acidic media and, due to their high subtativity, have poor wash off properties. Similarly dyes having a vinyle sulphone reactive system have poor alkaline fastness. The chemical bond between the vinyle sulphone dyes and cellulosic fiber is very stable to acidic hydrolysis. The substantively of hydrolyzed by products of vinyl sulphone is low, so washing off is easy. Monochlorotriazine have good fastness to light, perspiration and chlorine. The turquoise reactive dye shows an optimum dyeing temperature that is generally about 20°C higher than that of other dyes with the same reactive group. The flourotriazine groups forms linkages with cellulose that are stable to alkaline media. Reactive dyes of dichloroquinoxaline, monochlorotriazine and monoflorotrizine types show a tendency for lower resistance to peroxide washing and dyefiber bond stability. A lower sensitivity to changes in dyeing conditions (particularly temperature) is the most important characteristics feature of the monochlorotriazine – vinyl sulphone heterobifunctional dyes. Substativity: Substantivity more depends upon chromophour as compared to reactive system. A high substantivity may results: • Lower dye solubility. • High primary exhaustion. • A high reaction rate. • Lower diffusion coeffecient. A low sensitivity of dyes to the variation in the processing conditions such as time, temperature, pH, material to liquor ratio may results: • Less diffusion. • Less migration and levelness. • More difficult to the removal of unfixed dyes. Substantivity is also the best measure of the ability of a dye to cover dead cotton or immature cotton fibers. Covering power is best when the substantivity is either high or very low. An increase in the dye substantivity may be affected by: • Lower concentration of dyes. • Higher concentration of electrolyte. • Lower temperature. • Higher pH upto 11. • Lower liquor to material ratio (M:L) Reactivity: High dye reactivity entails a lower dyeing time and lower efficiency of fixation. To improve the efficiency of fixation by reducing dye reactivity requires a longer dyeing time and therefore less effective than an increase in substativity. Also there is wide range of 12

temperature and pH over which the dye can be applied. Altering the pH or temperature, two dyes of intricsically different reactivity may be made to react at a similar rate can modify reactivity of dye Solubility: Dyes of better solubility can diffuse easily and rapidly into the fibers, resulting in better migration and leveling. Increasing the temperature, adding urea and decreasing the use of electrolyte may affect on increase in dye solubility.

Materials and Methods: Materials: In the research work following materials were used. Fabric: Scoured and bleached, fluorescent brightener free woven 100% cotton fabric, twill weaves with a weight of 238g/m2 and density of 46 threads/cm in the warp and 20threads/cm in weft directions and the fabric Berger whiteness is 74.53% was used for pad dry cure dyeing. Dyes and chemicals: Commercial samples of Rifafix reactive dyes (Red, Blue and yellow) and Sumifix dyes (Red, Blue and yellow), wetting agent Sandozin MRN, which is poly glycol ether derivative, sodium Alginate were obtain from market. Sodium hydroxide sodium Bicarbonate, Soda Ash, Urea, DAP are AR Grade chemicals. Equipment: Pad dying was carried out by using a laboratory scale vertical Padder (Rapid). The samples were cured on the curing machine (Rapid). The colour coordinates were recorded on the Data Color Spectraflash SF 650X. Wash fastnesses were carried out on the IR dyeing machines (Aiba). Light fastness was carried out on Weather-o-meter. Experimental work: For the determination of colour sensitivity of two different brands of dyes three primary colours (Red, Blue and Yellow) has been used and by the combination of three colours a trichoromacity diagram has been developed. Standard recipe of PDC dyeing to measure colour sensitivity. By the combination of three colours we develop 66 shades of individual dye brand. Out of these 66 shades we chose three shades from 2 sets of combination, which we consider as target shades (Attached sheet). On similar pattern we produce these target shades by combination of two dye brands Similarly we determine the colour sensitivity of target shades of individual dye. The factors that effect colour sensitivity of target shades are curing time, urea concentration, pH and use of DAP. 13

To check the sensitivity of the dyes with reference to specific target shades standard Recipe of pad dry cure dyeing is given bellow. Standard Recipe of Pad dry cure dyeing: Dye stock solution = 10 gm/l Sodium Carbonate = 20 gm /l Urea = 150 gm/l Sodium Alginate = 20 ml of 2 % Stock solution Standard conditions for Pad dry cure dyeing: Fabric twill Pick up of Padder = 70 % pH = 11 Dyeing time = 90 sec Drying Temperature = 98 °C

Curing time = 60 sec Curing temperature= 160 °C

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15

16

17

COLOUR SENCITIVITY COLOUR MATCHING TRIANGLE BY PAD – DRY – CURE METHOD Tri chromacy dyeing Recipe 1 Y = 10 R=0 B=0

2

3

Y=9 R=1 B=0

Y=9 R=0 B=1

4

5

Y=8 R=2 B=0

6

Y=8 R=1 B=1

7

Y=8 R=0 B=2

8

Y=7 R=3 B=0

9

Y=7 R=2 B=1

10

Y=7 R=1 B=2

Y=7 R=0 B=3

11

12

13

14

15

Y=6 R=4 B=0

Y=6 R=3 B=1

Y=6 R=2 B=2

Y=6 R=1 B=3

Y=6 R=0 B=4

16

17

18

19

20

21

Y=5 R=5 B=0

Y=5 R=4 B=1

Y=5 R=3 B=2

Y=5 R=2 B=3

Y=5 R=1 B=4

Y=5 R=0 B=5

22

23

24

25

26

27

28

Y=4 R=6 B=0

Y=4 R=5 B=1

Y=4 R=4 B=2

Y=4 R=3 B=3

Y=4 R=2 B=4

Y=4 R=1 B=5

Y=4 R=0 B=6

29

30

31

32

33

34

35

36

Y=3 R=7 B=0

Y=3 R=6 B=1

Y=3 R=5 B=2

Y=3 R=4 B=3

Y=3 R=3 B=4

Y=3 R=2 B=5

Y=3 R=1 B=6

Y=3 R=0 B=7

37

38

39

40

41

42

43

44

45

Y=2 R=8 B=0

Y=2 R=7 B=1

Y=2 R=6 B=2

Y=2 R=5 B=3

Y=2 R=4 B=4

Y=2 R=3 B=5

Y=2 R=2 B=6

Y=2 R=1 B=7

Y=2 R=0 B=8

46

47

48

49

50

51

52

53

54

55

Y=1 R=9 B=0

Y=1 R=8 B=1

Y=1 R=7 B=2

Y=1 R=6 B=3

Y=1 R=5 B=4

Y=1 R=4 B=5

Y=1 R=3 B=0

Y=1 R=2 B=7

Y=1 R=1 B=8

Y=1 R=0 B=9

56 Y=0 R = 10 B=0

57

58

59

60

61

62

63

64

65

Y=0 R=9 B=1

Y=0 R=8 B=2

Y=0 R=7 B=3

Y=0 R=6 B=4

Y=0 R=5 B=5

Y=0 R=4 B=6

Y=0 R=3 B=7

Y=0 R=2 B=8

Y=0 R=1 B=9

66 Y=0 R=0 B = 10

18

19

20

21

22

23

24

25

26

27

COLOUR SENSITIVITY BY PAD – DRY – CURE METHOD SUMIFIX DYES DATA BASE (Before washing)

Recipe No 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

L*

a*

b*

C*

h

K/S

81.58 73.40 72.83 70.04 69.82 68.82 68.23 67.16 66.53 60.29 63.84 65.62 63.39 64.75 61.89 62.85 62.67 62.32 61.39 64.48 62.86 60.06 60.34 59.56 58.36 61.57 62.97 62.52 60.08 58.86 59.84 59.93 60.71 61.21

16.51 24.11 3.59 27.53 9.91 -1.06 29.33 13.98 4.13 -5.05 34.62 17.74 9.34 0.99 -7.80 36.57 21.28 13.09 5.08 -1.48 -8.77 40.13 24.45 16.46 10.05 3.40 -2.79 -9.77 41.17 27.62 19.11 13.06 7.11 1.63

55.70 43.53 45.41 36.38 32.47 37.20 29.55 24.62 25.98 33.17 23.05 18.35 19.39 18.52 23.58 17.76 13.94 12.29 12.65 13.16 16.84 13.18 7.53 5.70 5.88 5.92 6.37 10.36 6.66 1.57 -0.09 -0.57 -0.85 -0.03

58.10 49.76 45.55 45.62 33.95 37.22 41.64 28.31 26.31 33.55 41.60 25.52 21.52 18.55 24.84 40.66 25.44 17.96 13.63 13.24 18.98 42.24 25.59 17.42 11.64 6.83 6.95 14.24 41.71 27.66 19.11 13.08 7.16 1.63

73.49 61.02 85.48 52.88 73.02 91.63 45.22 60.41 80.96 98.65 33.66 45.96 64.28 86.95 108.30 25.91 33.23 43.18 68.12 96.42 117.51 18.18 17.12 19.09 30.33 60.11 113.69 133.31 9.19 3.24 359.72 357.49 353.16 358.82

2.2 2.38 2.72 2.2 1.96 2.55 1.88 1.63 1.88 3.7 1.9 1.4 1.67 1.54 2.35 1.6 1.4 1.38 1.5 1.26 1.52 2.1 1.5 1.37 1.38 1.12 1.4 1.29 2.2 1.8 1.46 1.28 1.10 0.97

28

Recipe No 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66.

L*

a*

b*

C*

h

K/S

62.23 62.19 60.41 57.36 57.56 56.41 57.67 59.27 59.93 63.19 64.18 59.73 57.95 56.38 56.24 57.21 52.09 56.31 58.71 62.07 57.98 59.36 55.18 53.74 53.76 52.86 55.85 57.35 57.42 53.14 55.90 63.33

-3.56 -10.35 40.94 29.81 23.00 16.14 12.23 6.56 1.60 -3.59 -9.41 44.28 32.47 25.56 20.68 15.45 12.03 7.41 2.42 -3.09 -9.32 46.82 34.83 28.34 23.23 20.66 14.92 9.61 6.72 4.16 -0.49 -5.24

0.41 3.29 -0.09 -4.41 -6.55 -9.12 -7.72 -7.26 -6.71 -6.39 -4.04 -5.47 -10.28 -12.75 -14.01 -14.95 -17.26 -15.85 -15.11 -14.27 -14.21 -12.48 -18.83 -22.04 -23.49 -24.98 -24.35 -25.32 -25.37 -28.82 -27.10 -23.53

3.59 10.86 40.94 30.14 23.91 18.54 14.46 9.79 6.90 7.33 10.24 44.61 34.06 28.56 24.98 21.50 21.04 17.49 15.30 14.61 17.00 48.46 39.59 35.90 33.03 32.42 28.56 27.08 26.25 29.12 27.11 24.11

173.37 162.36 359.87 351.58 344.09 330.52 327.74 312.10 238.41 240.67 203.21 352.96 342.43 333.49 325.88 315.94 304.88 295.07 179.09 257.77 236.76 345.08 331.60 322.13 314.60 309.59 301.51 290.78 284.84 278.22 268.96 257.45

0.93 1.22 2.19 2.18 1.86 1.8 1.52 1.25 1.1 0.97 1.14 2.52 2.2 2.18 2.0 1.72 2.28 1.6 1.27 1.19 2.05 2.72 2.8 2.68 2.42 2.47 1.85 1.58 1.5 2.2 2.19 1.48

29

30

COLOUR SENSITIVITY BY PAD – DRY – CURE METHOD SUMIFIX DYES DATA BASE (After washing)

Recipe No 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

L*

a*

b*

C*

h

K/S

82.23 76.59 74.97 73.98 73.51 72.22 73.97 71.23 70.68 63.89 68.03 60.85 69.92 68.90 65.89 67.35 68.29 66.48 65.47 68.77 66.12 66.70 65.72 64.97 61.90 66.12 66.95 63.91 66.07 64.58 64.60 64.99 66.04 65.31

10.64 17.85 0.97 20.96 6.40 -3.56 21.61 10.28 1.00 -6.91 29.06 13.68 5.40 -1.24 -8.80 31.39 16.04 9.28 2.31 -3.52 -9.76 32.47 19.16 12.21 6.85 0.61 -4.28 -10.93 34.77 22.39 14.72 9.01 3.95 -0.55

51.39 41.77 42.09 35.36 32.92 34.00 28.08 26.80 25.64 31.85 24.20 19.73 19.71 19.56 22.55 19.65 15.73 14.07 14.64 13.32 15.24 13.97 9.93 7.18 7.71 7.01 7.50 10.07 8.34 4.07 2.48 1.92 1.63 1.99

52.48 45.42 42.10 41.11 33.54 34.18 35.43 28.71 25.66 32.59 37.82 24.01 20.44 19.60 24.21 37.04 22.47 16.85 14.83 13.78 18.10 35.35 21.57 14.17 10.31 7.03 8.64 14.86 35.76 22.75 14.93 9.22 4.27 2.06

78.30 66.87 88.68 59.34 79.00 95.97 52.41 69.02 87.76 102.25 39.79 55.27 74.67 93.62 111.32 32.05 44.45 56.57 81.04 104.80 122.62 23.28 27.39 30.47 48.38 85.01 119.70 137.35 13.48 10.31 9.55 12.02 22.36 105.52

1.89 1.82 2.15 1.68 1.6 1.82 1.22 1.44 1.44 2.98 1.55 1.56 1.58 1.58 1.79 1.32 1.08 1.14 1.28 0.98 1.28 1.15 0.98 0.92 1.2 0.87 0.85 1.2 1.3 1.12 0.98 0.8 0.77 0.84

31

Recipe No 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66.

L*

a*

b*

C*

h

K/S

63.85 64.55 65.85 63.81 61.83 60.77 63.26 62.23 63.31 67.07 66.41 65.41 64.92 62.59 62.28 62.02 56.74 62.14 62.75 65.95 59.68 64.50 60.45 60.11 58.99 57.43 59.21 61.81 62.97 58.12 59.67 65.48

-5.21 -10.74 36.23 24.76 19.22 12.23 8.23 3.52 -0.58 -4.54 -9.35 38.10 26.80 21.26 16.18 11.84 8.24 4.20 0.33 -4.09 -9.43 42.01 30.28 23.28 19.95 16.94 12.05 6.34 3.88 1.58 -2.07 -5.47

2.24 3.09 2.04 -1.84 -4.39 -6.78 -5.30 -5.72 -5.09 -3.89 -3.91 -3.37 -7.30 -9.69 -10.78 -12.02 -14.03 -12.57 -13.14 -11.50 -13.63 -10.77 -16.57 -19.15 -21.01 -22.77 -22.40 -21.61 -20.68 -24.48 -23.78 -20.48

5.67 11.17 36.29 24.83 19.72 13.99 9.78 6.71 5.12 5.98 10.13 38.25 27.78 23.36 19.44 16.87 16.27 13.25 13.14 12.20 16.58 43.37 34.52 30.15 28.97 28.38 25.44 21.95 21.04 24.53 23.87 21.20

156.75 163.92 3.23 355.74 347.15 331.00 327.22 301.59 263.52 220.58 202.73 354.95 344.76 335.50 326.33 314.56 300.41 288.46 271.43 250.43 235.32 345.62 331.32 320.56 313.53 306.64 298.28 286.79 280.62 273.69 265.02 255.06

0.99 1.05 1.38 1.27 1.30 1.24 0.95 0.96 0.84 0.73 0.97 1.43 1.2 1.3 1.2 1.1 1.52 1.00 0.98 0.90 1.8 1.72 1.8 1.58 1.6 1.62 1.38 1.08 0.97 1.6 1.68 1.2

32

33

COLOUR SENCITIVITY BY PAD – DRY – CURE METHOD RIFAFIX DYES DATA BASE (Before washing)

Recipe No 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

L*

a*

b*

C*

h

K/S

78.27 72.64 72.68 70.04 67.49 69.29 67.50 67.04 64.95 65.63 65.85 66.46 63.68 62.45 65.63 61.76 64.56 60.35 63.76 61.10 65.66 62.79 62.87 61.35 61.30 61.84 61.61 64.51 60.41 55.67 62.97 57.95 62.96 60.79

16.30 20.87 3.46 24.09 7.61 -2.09 27.13 11.97 0.42 -4.33 29.22 14.34 7.47 -1.02 -6.69 34.01 18.20 11.15 4.60 -1.87 -8.02 33.10 20.23 14.10 7.03 2.17 -4.61 -9.15 36.78 23.63 15.78 15.54 6.06 0.72

56.69 45.10 40.79 37.30 33.45 32.34 30.71 26.26 22.22 27.47 24.72 19.53 18.53 17.82 21.16 18.11 15.56 13.59 13.81 15.79 15.15 11.95 9.64 8.86 7.94 7.74 6.02 9.01 7.18 3.08 1.73 -1.26 1.30 1.68

58.99 49.70 4094 44.41 34.31 32.41 40.98 28.86 22.22 27.81 38.28 24.23 19.98 17.85 22.20 38.53 23.95 17.58 14.55 15.90 17.14 35.19 22.41 16.66 10.60 8.04 7.58 12.85 37.47 23.83 15.87 15.59 6.20 2.00

73.96 65.17 85.15 57.14 77.18 93.71 48.55 65.49 88.92 98.95 40.23 53.72 68.04 93.28 107.54 28.04 40.54 50.63 71.57 96.77 117.88 19.86 25.48 32.15 48.49 74.37 127.48 135.44 11.04 7.43 6.25 355.38 12.09 68.85

2.18 2.00 1.95 2.10 2.22 1.77 2.00 1.5 1.47 1.95 1.52 1.18 1.18 1.54 1.45 1.42 1.17 1.25 1.00 1.30 1.02 1.09 0.86 1.00 0.98 1.08 0.96 0.96 1.29 1.38 0.74 1.10 0.75 0.89

34

Recipe No 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66.

L*

a*

b*

C*

h

K/S

59.75 63.07 58.71 60.80 60.71 61.27 60.78 60.48 60.67 59.69 60.68 59.12 58.42 58.14 58.45 57.52 59.47 54.58 60.91 60.12 60.46 58.35 57.41 56.41 54.99 55.22 57.10 55.58 55.36 57.30 57.68 61.83

-4.90 -9.55 39.96 23.71 19.02 13.18 9.70 4.97 0.73 -5.39 -10.20 41.13 30.35 22.98 17.65 14.12 8.87 5.21 0.38 -4.39 -9.24 43.62 31.63 26.39 22.20 17.84 11.32 9.19 5.03 1.62 -2.33 -6.82

0.97 3.74 1.70 -1.97 -2.87 -3.70 -5.25 -4.99 -5.47 -6.01 -3.42 -3.91 -8.58 -9.92 -10.96 -10.99 -12.47 -14.26 -11.27 -12.72 -10.48 -10.02 -13.45 -17.31 -18.74 -20.21 -19.51 -21.80 -22.37 -22.42 -21.88 -19.28

4.99 10.26 39.99 23.79 19.24 13.69 11.03 7.04 5.52 8.07 10.76 41.31 31.54 25.03 20.77 17.89 15.30 15.18 11.28 13.46 13.97 44.76 34.38 31.56 29.05 26.96 22.56 23.65 22.98 22.48 22.01 20.45

168.75 158.60 2.44 355.25 351.41 344.31 331.56 314.89 277.58 228.09 198.51 354.57 344.22 336.64 328.15 322.11 305.43 290.08 271.96 250.96 228.60 347.06 336.96 326.73 319.84 311.44 300.13 292.85 282.67 274.13 263.91 250.51

0.75 0.94 1.45 1.1 1.08 0.97 0.98 0.86 0.97 0.98 1.20 1.52 1.35 1.23 1.0 0.98 0.96 0.87 0.92 1.31 1.47 1.68 1.52 1.53 1.51 1.36 1.20 1.19 1.42 1.30 1.50 1.37

35

36

COLOUR SENCITIVITY BY PAD – DRY – CURE METHOD RIFAFIX DYES DATA BASE (After washing)

Recipe No 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

L*

a*

b*

C*

h

K/S

81.59 76.96 74.67 73.61 69.09 71.38 70.58 70.64 67.99 70.61 70.03 70.16 68.29 64.68 67.39 66.91 67.88 65.21 68.03 65.29 65.39 67.20 67.68 65.42 65.18 63.56 63.92 65.84 65.61 60.60 67.01 61.79 65.35 63.45

11.81 16.61 0.37 21.10 4.65 -4.52 25.15 8.27 -2.39 -4.23 25.97 10.63 3.53 -3.55 -8.78 30.46 14.48 7.22 1.53 -4.61 -9.69 31.54 16.05 10.35 3.73 -0.84 -6.42 -10.51 34.40 19.92 11.49 11.71 2.72 -1.64

53.28 43.97 39.56 39.86 33.82 31.04 34.22 26.70 21.38 22.38 26.71 20.63 17.29 17.27 20.00 20.47 16.73 13.82 13.05 14.41 13.71 14.54 9.83 9.40 8.14 7.50 5.10 7.96 8.79 4.16 2.31 -0.02 1.20 1.19

54.57 47.00 39.56 45.10 34.14 31.37 42.47 27.95 21.51 22.41 37.25 23.20 17.65 17.64 21.84 36.70 22.13 15.59 13.13 15.13 16.79 34.73 18.83 13.98 8.95 7.55 8.20 13.18 35.50 20.35 11.72 11.71 2.97 2.03

77.50 69.30 89.47 62.11 82.17 98.29 50.68 72.79 96.39 96.41 45.81 62.74 78.46 101.62 113.69 33.89 49.12 62.40 83.31 107.73 125.45 24.75 31.49 42.25 65.35 96.43 141.52 142.85 14.34 11.81 11.37 359.89 23.88 143.88

2.85 2.61 2.25 2.25 2.39 2.05 2.05 1.08 1.79 1.95 1.79 1.40 1.30 1.78 1.68 1.78 1.35 1.35 1.32 1.78 1.24 1.45 1.05 1.27 1.24 1.2 1.27 1.15 1.90 2.1 1.02 1.49 1.08 1.16

37

Recipe No 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66.

L*

a*

b*

C*

h

K/S

65.35 65.91 64.83 65.14 63.28 63.47 63.56 63.07 63.30 64.45 63.62 64.73 63.10 62.62 63.84 63.06 62.81 63.53 63.78 61.59 62.29 64.04 62.05 60.34 59.57 60.54 60.57 60.45 58.29 59.01 61.22 64.11

2.72 -10.13 36.76 20.28 16.24 10.20 6.63 2.35 -1.28 -5.97 -10.17 39.02 26.81 19.78 13.68 10.77 7.06 2.84 -0.73 -4.85 -9.28 42.11 29.78 24.14 20.19 1.38 10.05 7.48 4.48 1.78 -2.05 -5.55

1.20 1.95 2.82 -1.27 -1.81 -4.03 -5.38 -5.32 -6.30 -6.29 -4.87 -3.22 -8.08 -9.62 -10.44 -12.18 -12.60 -12.77 -12.47 -13.94 -13.18 -10.27 -15.13 -18.05 -20.06 -23.64 -21.60 -22.47 -24.54 -23.41 -23.61 -21.98

2.97 10.32 36.87 20.32 16.34 10.97 8.54 5.82 6.43 8.67 11.27 39.15 28.00 22.00 17.21 16.26 14.44 13.08 12.49 14.76 16.12 43.35 33.41 30.14 28.46 23.68 23.82 23.69 24.95 22.47 23.70 22.68

23.88 169.10 4.38 356.43 353.65 338.44 320.91 293.87 258.53 226.53 205.58 355.28 343.24 334.07 322.66 311.50 299.27 282.52 266.66 250.81 234.85 346.30 333.06 323.21 315.19 273.34 294.95 288.41 280.34 275.27 265.03 255.74

1.30 1.23 2.35 1.42 1.35 1.28 1.14 1.09 1.96 1.19 1.34 2.37 2.0 1.72 1.58 1.58 1.28 1.7 1.03 1.10 1.29 2.62 2.17 2.15 2.15 2.00 1.58 1.73 1.67 1.60 1.82 1.10

38

COLOUR SENCITIVITY BY PAD – DRY – CURE METHOD % FIXATION DATA BASE RIFAFIX DYES

Recipe No

(K/S)b

(K/S)a

% Fix

Recipe No

(K/S)b

(K/S)a

% Fix

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.

2.18 2.00 1.95 2.10 2.22 1.77 2.00 1.08 1.47 1.95 1.52 1.18 1.18 1.54 1.45 1.42 1.17 1.25 1.00 1.30 1.02 1.09 0.86 1.00 0.98 1.08 0.96 0.96 1.29 1.38 0.74 1.10 0.75

2.85 2.61 2.25 2.25 2.39 2.05 2.05 1.5 1.79 2.10 1.79 1.40 1.30 1.78 1.68 1.78 1.35 1.35 1.32 1.78 1.24 1.45 1.05 1.27 1.24 1.2 1.27 1.15 1.90 2.1 1.02 1.49 1.08

76.49 76.62 86.66 93.33 92.88 86.34 97.56 72 82.12 92.85 84.91 84.285 90.76 86.51 86.30 78.88 86.66 92.59 75.75 73.03 82.25 75.17 81.90 78.74 79.03 90 75.59 83.47 67.89 65.71 72.54 73.82 69.44

34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66

0.89 0.75 0.94 1.45 1.1 1.08 0.97 0.98 0.86 0.97 0.98 1.20 1.52 1.35 1.23 1.0 0.98 0.96 0.87 0.92 1.10 1.29 1.68 1.52 1.53 1.51 1.36 1.20 1.19 1.42 1.32 1.50 1.10

1.16 1.30 1.23 2.35 1.42 1.35 1.28 1.14 1.09 1.96 1.19 1.34 2.37 2.0 1.72 1.58 1.58 1.28 1.7 1.03 1.31 1.47 2.62 2.17 2.15 2.15 2.00 1.58 1.73 1.67 1.60 1.82 1.37

76.72 57.69 76.42 40 77.46 81.48 84.37 85.96 78.89 49.48 82.35 89.55 64.13 67.5 71.51 63.29 62.02 75 51.17 89.32 83.96 87.75 64.12 70.04 71.16 70.23 68 75.94 68.78 85.02 82.5 82.4 80.29

(K/S)b : K/S Value Before Soaping. (K/S)a : K/S Value After Soaping.

39

Experimental techniques For paper chromatography: For paper chromatography of the dyes, a solution of dye (1.00g/l) was prepared in aqueous Sodium hydroxide solution (1.00g/l). The solution was allowed to stand for several days to ensure that the reactive groups of the dyes were hydrolysed and then neutralized to pH 6 with acetic acid. Small volumes of the dye solutions were then spotted onto a small piece (2×4 inch) of whatman #1 filter paper. After drying, the papers were developed by standing them in a shallow pool of solvent in a closed jar and the chromatograms developed by the ascending technique. The developing solvents used were 2-propanol/water/acetic acid (18:17:1 by volume) Paper chromatography of hydrolysed dyes: The paper chromatography characteristics of 6 reactive dyes were examined by the ascending technique using the developing solvents. The Rf value was measured at least three times and the mean value calculated. The Rf value is the distance the dye spot travels from the origin (x) divided by the distance travelled by the solvent front (y). It was calculated as a percentage. Rf = (100 × x)/ y Paper chromatography Rf values correlate well with the substantivity of various types of dyes for cotton. This test therefore provides a rapid and inexpensive means of assessing the relative substantivity of reactive dyes for cotton.

Dye strength comparisons: When the strengths of two dyes of similar hue, brightness and fastness properties are being assessed absorptiometry is often employed. However, this does not always give an accurate estimate of the colour that will be achieved when a substrate is dyed, either with the individual dye, or the dye in combination with other dyes. For this reason reflectance measurements on dyed substrate are often used instead. This method suggested here would be to apply the individual dyes to a substrate by the approved procedure, at a medium depth, and also carry out a blank dyeing of the substrate with everything except the dye in the bath. The blank and the dyed substrate will then be measured and the hue angle of the dyed sample determined. The purity of the dyes was checked by chromatographic techniques. The Rf values of the dyes are given below it shows that Rifafix dyes are low substantive then Sumifix dye for Cotton. Rf values of dyes Rifafix Yellow Rifafix Red Rifafix Blue Sumifix Yellow Sumifix Red Sumifix Blue

= 70.76 = 56.92 = 64.61 = 52.36 = 46.15 = 49.23

40

Conclusion: Based on the concentration by weight of the initial solution of the dyes it is observed that the Rifafix yellow and blue dye absorbs more than Sumifix yellow and blue at any concentration. While absorbance of Sumifix red dye is more than the absorbance of Rifafix red dyes. (Table-1) Table:1 Spectrophotometer data of Rifafix and Sumifix. Reactive (Yellow, Red, Blue) Dyes. Sample No.

01 02 03 04 05 06 07 08 09 10 11 12

Dye concentration gm

λmax nm

-3

2.5 × 10 7.5 × 10 3 1.5 × 10 2 2.5 × 10 2 2.5 × 10 3 7.5 × 10 3 1.5 × 10 2 2.5 × 10 2 2.5 × 10 3 7.5 × 10 3 1.5 × 10 2 2.5 × 10 2

418

552

628

Absorbance of Rifa fix dyes

Absorbance of Sumifix dyes

0.422 1.204 2.615 3.053 0.408 1.321 2.602 3.514 0.314 1.011 1.739 2.145

0.421 1.202 2.332 3.050 0.457 1.437 2.741 3.562 0.313 0.906 1.726 2.126

Colour Measurement: The reflectance values and the corresponding CIE L,a,b,c & h coordinates & K/S values (at the appropriate λ max) for each target shade of the dyed samples were measured. This allows splitting of the total colour difference ΔE* into three parts lightness difference ΔL* hue difference ΔH* and chroma difference ΔC* Table-2: Limits of Accuracy for Right-First time dyeing. Factors Matching tolerance Cotton variability in dyeing Variability in water supply Computer prediction Instability of dye solution Variation in weighing of 5% Lab dyeing reproducibility Spectrophotometer reproducibility.

ΔE (JPC 70) 0.3~0.5 2.0 3.0 < 1.0 3.0~5.0 2.5 0.8 0.05~0.2

Comparison of target shades of individual dyes with respect to specific target shades by changing the conditions parameter the colour differences can be quantified by ΔE according to equation ΔE= [(ΔL*) 2 + (Δa*) 2 + (Δb*) 2] ½ 41

Commercial tolerance is often between 0.3-1 ΔE units. For target shade No.1 (Table-3), it was observed for Rifafix dyes the shade obtained by changing the curing time and also by decreasing the amount of urea is in acceptable range of tolerance limit. While for target shade No.1 (Table-4) with Sumifix dyes the acceptable shades are obtained by change in curing time and also by an increase or decrease in the amount of urea. For target shade No.2 (Table-5) with Rifafix dyes the shade are obtained either by decrease or increase in amount of urea and at low pH lie in the tolerance limit. For target shade No.2 (Table-6) with Sumifix dyes the dyeing do not match the target colour by increase in curing time, decrease in quantity of urea and at low pH. For target shade No.3 (Table-7) with Rifafix dyes the acceptable shades are obtained by increase in curing time, increase or decrease in quantity of urea and at high pH. For target shade No.3 (Table-8) with Sumifix dyes by the increase in curing time only the shade is acceptable. Table-3: Target Shade No1 with Rifafix dyes. Sample Changes K/S ΔE ΔL* Δa* Δb* ΔC Δh No 0.23 0.95 0.40 0.36 -0.78 0.85 -0.73 01 Curing time 0.26 0.21 -0.46 -0.78 02 Quantity of Urea Increased 0.274 0.44 -0.29 0.36 0.67 0.48 1.05 03 Quantity of Urea decreased 0.277 1.12 -0.83 0.281 1.03 0.68 -0.63 0.45 -0.81 0.54 04 High pH 0.276 0.97 -0.41 -0.09 0.8 8 -0.89 0.56 05 Low pH 0.35 1.27 -1.06 0.69 0.13 1.88 -0.77 06 DAP 5g/l Table-4: Target Shade No1 with Sumifix dyes. Sample Changes K/S ΔE No 0.23 0.35 01 Curing time 02 Quantity of Urea Increased 0.19 0.68 03 Quantity of Urea decreased 0.228 0.39 0.20 1.22 04 High pH 0.192 1.41 05 Low pH 0.347 1.84 06 DAP 5g/l Table-5: Target Shade No 2 with Rifafix dyes. Sample Changes K/S ΔE No 0.159 1.02 01 Curing time 02 Quantity of Urea Increased 0.20 0.57 03 Quantity of Urea decreased 0.22 0.91 0.214 1.19 04 High pH 0.216 0.64 05 Low pH 0.256 2.26 06 DAP 5g/l Table-6: Target Shade No 2 with Sumifix dyes. Sample Changes K/S ΔE No 0.195 1.57 01 Curing time 02 Quantity of Urea Increased 0.18 0.74 03 Quantity of Urea decreased 0.194 1.20 0.178 2.13 04 High pH 0.178 0.66 05 Low pH 0.242 2.15 06 DAP 5g/l

ΔL* 0.05 0.68 0.08 0.25 0.98 1.23

ΔL* 0.69 -0.26 0.63 1.06 0.62 -1.01

ΔL* 0.31 -0.05 -0.48 1.95 0.16 -1.79

Δa* -0.04 -0.02 0.37 -0.56 0.32 0.89

Δa* 0.71 0.50 0.38 0.69 0.15 1.36

Δa* -1.36 0.15 -0.88 -0.78 -0.25 1.01

Δb* -0.35 -0.10 -0.11 -1.06 -0.97 -1.04

Δb* -0.28 0.11 -0.54 0.13 -0.09 -1.51

Δb* 0.74 -0.72 -0.67 0.40 -0.59 0.62

ΔC -0.33 -1.82 0.08 -2.50 -1.09 -0.32

ΔC 0.89 0.44 -0.45 -1.26 0.16 1.25

ΔC -0.77 0.43 -0.09 -2.40 0.02 0.74

Δh -0.13 -1.04 -0.37 -0.70 -0.87 -0.45

Δh -0.92 -0.87 -0.32 0.39 0.07 -0.97

Δh 0.49 -0.59 0.49 1.34 -0.64 0.93

42

Table-7: Target Shade No 3 with Rifafix dyes. Sample Changes K/S ΔE No 0.175 0.46 01 Curing time 02 Quantity of Urea Increased 0.217 0.88 03 Quantity of Urea decreased 0.22 0.99 0.218 0.48 04 High pH 0.20 1.33 05 Low pH 0.347 3.48 06 DAP 5g/l Table-8: Target Shade No 3 with Sumifix dyes. Sample Changes K/S ΔE No 0.15 0.49 01 Curing time 02 Quantity of Urea Increased 0.19 1.28 03 Quantity of Urea decreased 0.204 1.40 0.232 2.33 04 High pH 0.20 2.04 05 Low pH 0.273 1.22 06 DAP 5g/l

ΔL* 0.42 -0.70 -0.71 0.27 -0.04 -3.18

ΔL* -0.08 1.03 -0.05 1.30 -0.05 -1.03

Δa* 0.12 -0.19 -0.63 0.30 -0.86 -1.05

Δa* 0.30 0.50 -0.32 1.50 4.59 0.65

Δb* -0.16 0.60 0.28 0.26 1.02 -0.98

Δb* 0.38 -0.58 -1.36 1.23 -1.28 0.03

ΔC -0.22 0.72 0.30 0.29 1.38 -1.19

ΔC 0.11 -0.93 -0.59 1.50 1.37 -0.33

Δh -0.19 0.46 0.62 -0.35 0.83 1.93

Δh -0.40 -0.08 1.27 -1.31 -2.03 -0.65

43

44

45

46

47

48

49

50

51

52

Build-up properties: The use of a combination of different types of dyes to achieve deep shades requires the components to have a high degree of compatibility. Proper selection requires to build-up properties of the individual dyes to be known. The colour yields of the Rifafix and Sumifix reactive dyes studied are shown in fig. Dye concentration Vs K/S values

Dye concentration Vs K/S Value 5

3

K/S

K/S

5

3

K/s Rifafix Blue K/s Rifafix Red

K/s Sumifix Blue

K/s Rifafix Yellow

K/s Sumifix Red

1

K/s Sumifix Yellow

0

2

4

Dye concentration (%)

6

1 0

2

4

6

Dye concentration (%)

For each complete dying the K/S values was determine at different concentration. For both the dyes the values of K/S increases as the dye concentration increases, which shows good build up developing. Sumifix red dye shows a good build up devolving at low concentration as compared to Rifafix red, while Sumifix (blue and yellow) and Rifafix (blue and yellow) behave in more or less same pattern.

Selection of optimum dye combinations of recipe preparation: We have already considered how a typical computer formulation program can be designed to predict all possible recipes from a given dye selection to match a given colour target. The resultant recipes can be sorted in order of cost or metameric index. Cost and metamerism are not of course the only factors to be considered in choosing the optimum dye combination. Before a final recipe is selected from the colour-matching computer we must take into consideration the other factors such as compatibility of dyes, fastness characteristics, leveldyeing properties and stability of recipes. In addition to the primary requirements for the selection of optimum dye recipe such as fastness and cost effectiveness the following factors may also be considered. Colour yield and build-up performance. Compatibility, i.e. rate of dyeing, build-up, blocking effects on other all of which must be assessed by reference to manufactures literature or by practical dyeing tests. Level-dyeing behaviour assessed by strike-migration test. Colour constancy in different illuminates, the object being to select where possible only those dyes, which show minimal, shade alteration in such circumstances. Selection of homogeneous dyes, where dye makers do not supply information on this aspect, the dye samples are subjected to chromatographic analysis or by trichromatic triangle.

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References: 1. CIE Publ. No.15.2, Colorimetry, Second Edition (1986). (No.15.3 to be published). 2. R.McDonald, Acceptability and perceptibility Decisions using the CMC Colour Difference formula, Textile Chemist and Colorists 20-6, (1988). 3.

J Park, JSDC, 107 (1991)93.

4. R. Stanziola, Col. Res.Appl., 5(1980)129. 5. D.G.Phillips, Col. Res. Appl., 7(1982)28. 6. D.H.Alman, Col. Res. Appl, 11 (1986)153. 7. B.Sluban, Col. Res. Appl., 20 (1995) 226. 8. F J J Clarke, R McDonald and B Rigg, JSDC, 100 (1984) 128,281. 9. H.Zolinger, Color Chemistry, Wiley - VCH, 380 (2003). 10. A.R.Horrocks, Handbook of Technical Textile, Wood head Publishing, 211 (2000). 11. V.Globo, Influence of Anionic Dye Sorption Properties on the Color of Wool Top, Tex.Res.Journal, (2004). 12. R.McDonaldd, Color Physics for Industry, SDC Bradford, U.K, 358(1997). 13. W.F.Beech, Fiber Reactive Dyes, Logos Press Limited, London, 343 (1970). 14. S.Asolekar, Environmental Problems in Chemical Processing of Textiles, IIT, Delhi, 18(2000). 15. P.Fowler, New Trichromatic System for enhanced Dyeing by the Exhaust Process, American Dyestuff Reporter (1997). 16. Imada, K.Harroda.N.1992, Recent developments in the optimized dyeing of cellulose using reactive dyes.J.Soc.Dyers & Colourist108: 210-214. 17. AATCC Test Method 153 – 1985:Color Measurement of Textile: Instrumental, Technical Manual of the AATCC, 272 –277(1995).

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