Nowadays, some of the synthetic dyes are carcinogenic or toxic in nature and they cause skin diseases, allergy. They are harmful for plants, fish and other living organisms in water. So they upset ecological balance. Tri- functional reactive dyes are introduced to overcome this problem. They have extensive fixation rate and also they are eco- friendly in nature due to least dyeing residue. India is famous for its multi coloured textiles. Thermochromic colourants are one kind of micro encapsulated dyes that can reversibly change their colour by temperature change.


When temperature rises to specific temperature, the color changes. The color starts fading back to original color as pigment is cooled down. The advantage of using tri- functional colors is that the dye exhaust to the extent of 92 (+ $- 3%). Some of them also need less salt. So this process is pollution free and eco- friendly process. Tri- functional colours are especially designed to get cloudy effect on fabric. It resembles the tie and dye effect. They have no sharp boundaries and are less laborious.


This endeavor study was done to introduce tie and dye effect through Trifunctionalcolous / thermo chromic colours. In this study, tri- functional colours were used to create vivid design resembling tie & dye effect. To attain the specific objectives of the study, it was divided into different phases- firstly; the fabric was scoured, and then dyed with tri-functional reactive dyes. After dyeing, fabric was tied with thread at different points. Then, samples were discharged and neutralized. After this, properties of both the samples (Tri-functional dyed sample and traditional tie and dyed sample) were assessed such as washing fastness, sunlight, ironing, rubbing and dry-cleaning and compared with each other and samples were evaluated by respondents.


The result showed that the cloudy effect and tie and dye effect had good to excellent fastness properties. Not much difference was found between the properties of both the samples. Cloudy effect and tie and dye samples were highly accepted by respondents.


Dyeing of textile is a very tricky process, which needs a lot of skill and definitely sound technical knowledge. Most of the dyeing in textiles is reactive. ie. Reactive dyes are used.

These reactive dyes have brilliant shades, excellent wet fastness of dyeing due to covalent bond. There are many types of reactive dyes- Mono-functional, Bi-functional, Tri-functional reactive dyes. Tri-functional reactive dyes have reduced salt content and colour.


"Tri-functional dyes or colours" are especially designed for garment industry to get cloudy effect on garment. This cloudy effect resembles the tie and dye effect but is different from the above effect in following aspect.


 

Tri-functional reactive dyes or Thermo-chromic colourants are one kind of micro-encapsulated dyes that can change their colour by variation in temperature. When the temperature rises to a specified point, the colour changes. The colour starts fading back to the original colour as temperature cools down.


Comparative Analysis

S. No

Type of Fabric


Type of Dye

Wash Fastness

Ironing Fastness

Rubbing fastness

Dry Cleaning

Sunlight fastness

CC

SC


CC

SC


CC

SC

CC

SC

CC

SC

1

Cotton Khadi

A

Direct Dye

4/5

3/4

Wet

4/5

3/4

Dry

4/5

5

4/5

5

4

4/5

Dry

5

5

Wet

4

4/5





Damp

5

5








B

Tri-functional reactive dye after neutralizing and discharging.

5

4/5

Damp

5

5

Wet

5

4/5

5

4/5

4/5

5

Dry

5

5

Dry

5

5





Wet

4/5

4/5








C

Tri-functional reactive dye before neutralizing and discharging.

5

5

Damp

5

5

Dry

5

5

4/5

5

5

5

Dry

5

5

Wet

5

4/5





Wet

5

5








2

Silk Khadi

A

Direct Dye

4/5

3/4

Damp

5

5

Wet

4/5

5

4/5

5

4

4/5

Dry

5

5

Dry

5

4/5





Wet

4/5








B

Tri-functional reactive dye after neutralizing and discharging.

5

5

Damp

5

5

Dry

5

5

4/5

5

5

4/5

Dry

5

5

Wet

5

4/5





Wet

5

5








C

Tri-functional reactive dye before neutralizing and discharging.

5

5

Damp

5

5

Wet

5

5

4/5

5

5

5

Dry

5

5

Dry

5

5





Wet

5

5









There in no sharp boundary as in case of tie and dye. There is merging effect where one colour gradually merges with another. Tie and dye produces, multicolour effect. Though sounding so simple, it is actually a complicated and skilled work of ornamenting the cloth with the combination of colours.


So this process is time consuming and there is wastage of dye. This process also produces pollution. So, to overcome these disadvantages, salt free reactive dyes were introduced in international market in the year1994.


They require less or no salt so it is cheaper and pollution free to create cloudy effect through tri-functional reactive dyes.

 

Thenceforth, the present study was conducted with the following objectives which included:

  1. To create novel effect on khadi fabric using ''Tri-functional colours".
  2. Comparative analysis of techniques of both ''Tri-functional colour and tie and dye".
  3. To evaluate the colour fastness towards light, washing, rubbing and ironing.


Materials and Methods:


In order to achieve the objectives, the proposed work was divided into following heads:

  1. Materials: Fabric (Pure white cotton khadi and silk khadi), dyes (Tri-functional reactive dyes and direct dyes), chemicals, instruments.
  2. Methods:
    • Pretreatment for the fabric-scouring.
    • Dyeing: Cotton khadi and silk khadi fabric were dyed with direct dye and reactive dye to creative tie and dye effect. Fabrics were dyed with tri-functional reactive dyes to create cloudy effect.
    • Tying: Samples of each technique were tied at different positions in different style with thread as per the effect to be achieved.
    • Discharging and Neutralizing of the samples dyed with trifunctional reactive dyes.
    • Assessment of properties of both samples (Try-functional dyed sample and tie and dye sample) for washing, ironing, dry-cleaning, sunlight and rubbing.
    • Analysis of properties.
    • Evaluation of samples according to over all appearance and developed design effects of both the techniques. A sample of 50 respondents was selected for evaluation of appearance and design effect of cloudy effect and tie and dye effect. A rating scale was prepared to assess over all appearance and design effect of cloudy effect and tie and dye effect
    • Analysis of data: The collected data was analysed. Frequency and weighted mean were calculated.


Results and Discussions

The results of the study have been discussed under following heads:


Colourfastness of multi-coloured cotton khadi and silk khadi samples

It was found that the cloudy effect and tie ad dye effect had good to excellent fastness properties towards washing, dry-cleaning, ironing, rubbing and sunlight.


Comparison of colourfastness of the multicoloured samples

All the properties of both the samples were same i.e. good to excellent except in case of wash fastness, result was good.


 

Evaluation of tie and dye and cloudy effect samples on the basis of over all appearance and developed design effects

Tie and dye samples were highly accepted due to their overall appearance where as cloudy effect samples were highly accepted by the respondents because of the developed design effect.


Conclusion:


This multi-coloured cloudy effect opens unlimited opportunities for garment/Textile industry to create vivid design. This technology is easy and simple as compared to traditional tie and dye process. It saves water and labour involved in the traditional tie and dye process. These dyes are eco-friendly in nature due to less dye residue.


Originally Published in the New Cloth Market, February, 2012.