Colorimetric Analysis of Salt-free Reactive Dyestuff on Textile Materials

Colorimetric Analysis of Salt-free Reactive Dyes on Textile Materials

Hadiul Islam¹, Ariful Hasan and Sarif Khan
Department of Textile Engineering
Northern University Bangladesh
Email: eng.hadiul@gmail.com¹

Abstract
Reactive dyes are mainly used for dyeing cellulose fibers such as cotton and viscose, but they are also increasingly gaining importance for wool and polyamide. The range of available reactive dyes is wide and enables a large number of dyeing techniques to be used. Poor dye fixation has been a long-standing problem with reactive dyes in particular in batch dyeing of cellulose fibers, where a significant amount of salt is normally added to improve dye exhaustion (and therefore also dye fixation). For further process, the project concluded salt-free reactive dyes and for that the process obtained with shade variation in different color types of fabric.

CHAPTER 1
INTRODUCTION

1.1 Introduction
In conventional method of dyeing of cotton with reactive dyes, alkali pH is should maintain in the dye bath. This method requires more electrolytes for exhaustion and alkali for fixation. In this paper the fiber modification technique based on polyacrylamide is discussed. When the fabric is treated with polyacrylamide, the primary hydroxyl groups of cellulose is (partially) modified into a amide groups, which intern leads the cellulose to act like as wool fiber and hence reactive dyes can be dyed on cotton at neutral pH in the absence of electrolyte and alkali. When dyeing the modified substrates, reactive dyes can be much more efficiently exhausted and fixed onto cellulosic fabrics under neutral conditions in the absence of salt. The modifications show an overall suitability for different reactive dyes. The modified dyeing do not suffer either from a significant drop in light fastness, wash fastness or from duller shades.[1]

1.2 Objectives

• To monitor the colorimetric difference on textile material for salt-free reactive dyes.
• To know about the process of salt-free reactive dyes.
• To establish the colorimetric difference.
• To determine the procedure of salt free reactive dyeing.
• To obtain the recipe of an effective dyeing process.

CHAPTER 2
LITERATURE REVIEW

2.1 Reactive Dye
Reactive dye is a class of dye that makes a covalent bond with the fiber and becomes an integral part of the fiber. These are usually used to dye cellulosic fibers such as cotton, rayon, or flax, but polyamide, wool, silk, and acetate fibers can also be dyed using reactive dyes.[2]

Reactive dyes are so-called because this is the only type of dye that has a reactive group. This group reacts chemically with the fiber polymer molecules to form covalent bonds. This covalent bond is formed between the reactive group and terminal –OH group of cellulosic fibers and terminal –NH² group of polyamide and wool fiber.

If we assume the general structure of reactive dye is S–F–T–X, then this can be described as: [2]

S–F–T–X + fiber = S–F–T–X–fiber

Where,

S = Solubilizing groups (such as SO₃Na or COONa or combination of both)
F = ChromopHoric group usually an azo, metal-complex azo, anthraquinone, etc.
T = Bridging group which attaches the reactive system X to the chromogen F; Usually, –NH, –O–, –NHCO–, –OCH₃–, –SO₃–, etc.
X = Reactive system or group, which reacts chemically with the functional group of the fiber [2]

2.2 History of Reactive Dye:
The launch of the first fiber-reactive dyes for cellulose in 1956, a century after the development of the first synthetic dye, enabled new and high fastness properties to be obtained. Reactive dyes have the unique property that they are designed to bond covalently with the substrate on application. They are principally used for dyeing and printing of cellulose, have been used to a lesser extent on polyamides but are used for important outlets in the coloration of wool and silk. Their brilliance of shade and high fastness to washing makes this class of dye ideal for materials that are subjected to frequent wash-wear cycles, which has become increasingly important with changes in fashion and washing practices.[3]

Reactive dye is most popular system for coloring cellulosic fibers. It can be used on nylon and wool dyeing. These fiber have low utilization property from other dyestuff.

These dyes is mainly created to dyed cellulosic fiber. The dye were invented in 3 types and name of those are-

1. Procion Yellow R
2. Procion brilliant Red 2B
3. Procion Blue 3G

Reactive dyes were first used in 1956 though, it was invented by steepens and Retteein Blackly in 1954,while they were working on ICI company (UK).[4]

For this invention they were award gold medal of the society of dyes and colorists in 1960. These dye arrived in our country in mid-60’s and become much popular during 80’s.[4]

2.3 Properties of Reactive Dye

• All types of shades are available from these dyes.
• Reactive dyes are found in powder, liquid, and print-paste form.
• Reactive dyes are soluble in water.
• They have very good light fastness with a rating of 6. The dyes have very stable electron arrangements and can protect the degrading effect of ultra- violet rays.
• Textile materials dyed with reactive dyes have very good wash fastness with a rating of 4-5 due to strong covalent bonds formed between fiber polymer and reactive group of dye.
• Reactive dye gives brighter shades and has moderate rubbing fastness.
• Reactive dyes have good perspiration fastness with rating 4-5.

2.4 Chemical Structure of Reactive Dye

2.5.1 On the basis of reactive group:[2]

Halogen

• Triazine group:procion,cibacron
• pyrimidine group:reactone
• Quinoxaline group:Levafix

Activated vinyl compound

• Vinyl sulpHone:remazol
• Vinyl acrylamide: primazine
• Vinyl sulpHonamide: levafix

2.5.2 On the basis of reactivity:[2]

• Lower reactive dye: here pH is maintained 12-12.5 using NaOH in bath
• Medium reactive dye: pH is maintained 11-12 by Na₂CO₃
• Higher reactive dye: pH is maintained 10-11 using NaHCO₃

2.5.3 On the basis of dyeing temperature:[2]

Cold Brand Reactive Dyes
These types of dyes contain reactive groups of high reactivity. So dyeing can be done in lower temperature i.e. 32-60°C. For example: PROCION M, LIVAFIX E

Medium Brand Reactive Dyes
This type of dyes contains reactive groups of moderate reactivity. So dyeing is done at higher temperatures than that of cold brand dyes i.e. in between 60-71°C temperatures. For example, Remazol, Livafix are medium brand dyes.

You may also like: Different Types of Reactive Dyes: Properties, Structures and Factors

Hot Brand Reactive Dyes
This type of dye contains reactive groups of least reactivity. So high temperature is required for dyeing i.e. 72-93°C temperature is required for dyeing. For example PROCION H, CIBACRON are hot brand dyes.

Table 2.1 Recent Classification of Reactive Dye:[2]

2.6 Dyeing Mechanism of Material with Reactive Dye:[4]

Dye absorption:
When fiber is immersed into dye liquor, an electrolyte is added to assist the exhaustion of dye. Here NaCl or global salt used as a electrolyte. This electrolyte neutralize absorption

Fixation:
Fixation of dye means the reaction of reactive group of dye with terminal -OH or NH₂ group of fiber and thus forming strong covalent bond with the fiber. These phase is very important. In this phase pH maintain by adding alkali.

Wash off:
As the dyeing is complete, a good wash must be applied to the material to remove extra and unfixed dye. Wash off is need for level dyeing and good wash fastness. It is done by a series of hot wash, cold wash and soap solution wash.

2.7 Color Variation of Reactive Dye:[4]

• Light (0.25%)
• Medium (0.75%)
• Dark (2%)

CHAPTER 3
MATERIALS and METHODS

3.1 Substrate
To obtain the perfect process and result the following specified materials are used:

Table 3.1: Fabric Specification

For the record, the source location for the fabric is Mondol Fabrics ltd. (Namopara, Kasimpur, Gazipur, Dhaka)

3.2 Methods

Table 3.2: Recipe for Salt free Reactive Dye

3.2.1 Specification of the Dyes Used

3.2.2 Other Ingredients Specifications:

3.3 Dyeing Process Sequence of Salt-free Reactive Dyes

Collection of pre-treated sample

↓

Add measured water

↓

Add Dye solution

↓

Add Sample Fabric

↓

Raise Temperature to 60°C

↓

Run Time for 20 minutes

↓

Bath Drop

↓

Rinsing

↓

Hot wash at 90°C for 10 minutes

↓

Dry

3.4 Dyeing Curve

3.5 Rubbing Fastness
Rubbing fastness is one of the most important test in the color fastness of textile, that means degree of fading after friction. This test is designed to determine the degree of color which is transferred from the color fabric to the test cloth.

3.6 Principal
Sample of textile is rubbed with dry rubbing cloth and with wet rubbing cloth by rubbing finger. The staining of rubbing cloth is assessed with grey scale for staining. The procedure followed by (ISO-105-X12).

3.7 Types of Rubbing Fastness

• Dry Rub
• Wet Rub

3.8 Apparatus Needed

• Crock Meter,
• Grey Scale for staining

3.9 Rubbing Procedure

• The test sample (15Cm×5Cm)is placed on the crock meter
• A square of white test fabric (5cm×5cm) that is de sized, bleached but without finish cotton fabric is taken for test
• Test cloth attached to the finger of crock meter.
• This finger is used in rubbing action on the sample specimen.
• Rubbing is done to and fro, 10 cycle at 10 second, figure pressure on the specimen is 9N.
• Rubbing is done both warp and weft way of the a sample
• For dry and wet rubbing test separate sample is used
• For wet rubbing M:L ratio maintains 1:50, after wetting fabric is squeezed.

3.10 Assessment Technique

• The tested sample is compared with dyed sample and under light box using D65 light source and rated by the help of color change gray scale.
• The Dry rubbed crock cloth also visually assessed under light box with D65 light source and rated with the help of color staining gray scale.
• In case of wet rubbed cloth at first it assessed after drying the crock cloth the procedure was same as dry rubbed crock cloth.

3.11 Resulted Figure of Rubbing Fastness Fabric

3.12 Color Fastness Test of Fabric:
Colorfastness can be measured by numerous methods, those are discussed below:

1. Low-Temperature Launder-Odometer:
It is a process used to test colorfastness to washing or rubbing by an accelerated method. This device is used by the textile industry to simulate industrial procedures. During this process, clothes are put in containers with detergents/cleaning agents and metallic balls for friction and then evaluated for colorfastness quality.[6]

Perspirometer:
It is used to test the resistance of clothing colors to water and perspiration. Solutions similar to sweat in the composition are used to wet clothes and then pressure is applied to them. In this way, color fastness is assessed via visual or instrumental means.[6]

Electronic Crock Meter:
This device tests colorfastness to dry or wet rubbing. Nowadays, electronic crock meter is used in the textile industry instead of the mechanical one.[6]

Color Matching Cabinet:
It is used to access colorfastness visually. Fabric that undergoes minimal color discoloration when exposed to all these agitating forces is said to have great colorfastness whereas the fabric which undergoes a lot of color discolorations during these tests is said to have poor color fastness or color strength.[6]

2. Weather-o-meter:
This is a machine used to test colorfastness against sunlight. Artificial lights used for this purpose and the number of hours to which clothes were exposed to this light are evaluated.[6]

3. Launder-o-Meter:
Also used to test colorfastness against washing of clothes.

4. Surface Abrader:
It is a machine used to determine colorfastness against frosting. It usually depends on the dye penetration in clothes.[6]

5. Gas Fading Chamber:
Nitrous oxide is always present in our atmospHere which is a result of burning fumes. Colorfastness can be affected by this chemical, in this chamber, clothes are exposed to nitrous oxide and evaluated for color fasting strength.[6]

3.13 CCM

• In computer color matching, we have to first make an attempt to quantify col- ours by virtue of a unique reflectance pattern that each color exhibits and then match this unique pattern by a blend of various dyes.
• The blend that gives an identical reflectance pattern is an exact match for the de- sired color.
• For this, we have to collect the spectral reflectance data for both the standard col- our and the dyes.

This data is then to be analyzed by using Kubelka-Munk equation:

• K/S= [(1-r)2 / 2r]
• Where r is the reflectance value of samples at a given wavelength,
• K/S= color strength

The basic three things of CCM are:

• Color measurement instrument (SpectropHotometer)
• Reflectance (R%) from a mixture of dyes
• Optical model of color vision

This model gives us the L* a* b* value, from which we can calculate c*, h* and E.

Where,

L*= L Standard – L Sample
a* = a standard– a sample
b* = b standard–b sample and,
E = (L2 + a2 + b2)1/2

*If E is more than 1, then the result is declared as fail or the recipe is rejected.

*Also the color strength must be ±100, or else the recipe is rejected.

For example:

• We have dyed a lab-dip using Jakazol dyes in e-control process.
• Shade name: STD NAVY

Prediction recipe:

Jakazol Yellow CE= 4.50 gpl
Jakazol Red CE= 13.50 gpl
Jakazol Blue CE= 23.00 gpl

CHAPTER 4
RESULT and DISCUSSION

4.1 Effect of Dyeing with Reactive Dye
Reactive dyes form covalent bond with cotton through neucleopHilic substitution or neucleopHilic addition mechanism and the dyes are familiar as substitutive and additive dyes respectively. Due to presence of strong dye–fibre interaction, fastness properties are remarkably good except wash fastness which is poor to moderate due to hydrolytic nature of dyes. Predissolved dye is applied on cotton; salt is added for better exhaustion followed by fixation with alkali. Subsequent soaping and washing remove all superficial and hydrolysed dyes.

4.1.1 Dyed Fabric

4.2 Data Analysis

Table 4.1 Assessment for rubbing fastness of knit fabric (light shade)

Table 4.2 Assessment for rubbing fastness of knit fabric (medium shade)

Table 4.3 Assessment for rubbing fastness of knit fabric (dark shade)

Table 4.4 Comparison between rubbing fastness shades of knit fabric

4.3 Chart Diagram Comparison between Rubbing Fastness Shades

Table 4.5 Effect of Color Fastness to Rubbing
Effect of color fastness to rubbing according to shade depth

4.4 Chart Diagram of Effect of Color Fastness to Rubbing

Table 4.6 Color Fatness to Wash
The result of color fastness to wash according to different shade depth is given below:

4.5 Chart Diagram for Color fastness to Wash

This figure represents significant change on color fastness to rubbing and washing according to acid and alkali based solution for different solution. With the increase of shade depth color fastness to rubbing and washing was changed on color and also its staining was increased.

Table 4.7 Color Fastness to Perspiration (Acid)
Effect of Color Fastness to Perspiration (Acid)

4.6 Chart diagram for Color Fastness to Perspiration (Acid)

Table 4.8 Color Fastness to Perspiration (Alkali)
Effect of Color Fastness to Perspiration (Alkali)

4.7 Chart Diagram for Color Fastness to Perspiration (Alkali)

The figure represents significant change on color fastness to perspiration was decrease on color shade depth (1% to 8%) when dye molecules arrest  the threads at the interlacement positions. It’s staining is increased according to acid and alkali based solution.

Table 4.9: Comparison between Color fastness shade differences

4.8 Chart Diagram of Color Fastness Shade Difference

4.9 Spectrophometer Test Reports:

Table 4.10: Reactive Dye Sample one 10 Minutes and K/S Values

[ K/S Dyed: 0.70 K/S, K/S Washed: 0.70 ]

Table 4.11: Reactive Dye Sample two 15 Minutes and K/S Values

[ K/S Dyed: 0.68, K/S Washed: 0.70 ]

Table 4.12: Reactive Dye Sample three 20 Minutes and K/S Values

[ K/S Dyed: 0.66, K/S Washed: 0.70 ]

Table 4.13: Reactive Dye Sample four 25 Minutes and K/S Values

[ K/S Dyed: 0.66, K/S Washed: 0.69 ]

Table 4.14: Reactive Dye Sample five 30 Minutes and K/S Values

[ K/S Dyed: 0.67, K/S Washed: 0.66 ]

4.10 L, A, B value K/S

CHAPTER 5
CONCLUSION

5.1 Conclusion
Pretreatment of cotton with polyacrylamide enhances the possibility of dyeing cotton at neutral pH with various commercial reactive dyes. Such pretreatment, as applied through pad dry cure process, brings about some chemical changes in the treated fabric. Fastness properties are adequate and quite comparable with conventionally dyed samples. The wrinkle resistance of the dyed fabric also improves. The dyeing of cotton with reactive dyes using polyacrylamide in the dye bath improves the dye ability of cellulosic fabrics with reactive dyes and reducing effluent discharge. When dyeing the modified substrates, reactive dyes can be much more efficiently exhausted and fixed onto cellulosic fabrics under neutral conditions in the absence of salt. The modifications show an overall suitability for different reactive dyes. The modified dyeing do not suffer either from a significant drop in light fastness, wash fastness or from duller shades.

5.2 References

[1] https://www.fiber2fashion.com/industry-article/1661/salt-alkali-free-reactive- dyeing-on-cotton *

[2] https://textilelearner.net/reactive-dyes-classification-dyeing-mechanism/

[3] https://www.textiletoday.com.bd/the-history-development-and-exploitation-of- fiber-reactive-dyes/*

[4] http://dspace.daffodilvarsity.edu.bd:8080/bitstream/handle/123456789/3210/P1262 4%20%2828%25%29.pdf?sequence=1&isAllowed=y*

[5] https://www.researchgate.net/figure/Chemical-structure-of-reactive- dyes_fig1_277325642*.

[6] https://www.sapub.or

[7] Anbumani, Knitting Fundamentals, Machine, Structures and Developments, First Edition, New Age International Publishers, New Delhi, 2007, 274pp.

[8] http://en.wikipedia.org/wiki/Cotton.

[9] Ramasamy, M. and Kandasaamy, P. V, 2005, Effect of cationization of cotton on its dyeability, Indian Journal of Fiber & Textile Research, 30(3), 315- 323.

[10] Mottaleb, M., and Littlejohn, D., 2001, Application of an HPLCeFTIR modified thermospray interface for analysis of dye samples, US National Library of Medicine National Institutes of Health, 17(3), 429-434

[11] Al-Degs, Y.S., El-Barghouthi, M.I., Khraisheh, M.A., Ahmad, M.N., and Allen, J., 2004, Effect of surface area, Micropores, secondary micropores and mesopores volumes of activated carbons on reactive dyes adsorption from solutionon, Separation Science and Technology, 39(1), 97-111.

[12] Saeed, Q., I.A. Bhatti, M. Zuber, S. Nosheen, M.A. Zia and M. Abbas., 2013, “Study of application of mono azo reactive dyes on cotton by exhaust method and printing properties”, International Journal of Basic & Applied Sciences, 12(6), 191-197.

[13] ISO 105-C04:1989; Textiles Tests for color fastness- Part C04: Color fastness to washing: Test

[14] ISO 105-X12:2001; Textiles Tests for color fastness– Part X12: Color fastness to rubbing.[9]ISO 105 E04:1994; Textiles Tests for color fastness- Part B02: Color fastness to

ANNEX

You may also like:

1. Salt Free Dyeing of Cotton Fabric with Reactive Dyes
2. Salt and Alkali Free Reactive Dyeing on Cotton Fabric
3. Comparative Study of Cotton Fabric Quality Using Different Salts in Reactive Dyeing Process
4. Function of Salt in the Textile Wet Processing
5. Reactive Dyes: Classification, Dyeing Mechanism, Application & Stripping
6. Dyeing of Cotton Fabric with Reactive Dyes
7. Printing of Cotton Fabric with Reactive Dyes
8. Different Types of Reactive Dyes: Properties, Structures and Factors
9. Different Types of Dyeing Process of Reactive Dye

Mazharul Islam Kiron

Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.

Share this Article!