PRINTING ON POLYESTER FABRIC WITH DISPERSE DYE:

Printing on Polester fabric with disperse dyes:-

For printing on polyester fabric with disperse dye the selection of thickener is very important. The print paste should adhere on the fabric surface and penetrate in to it. During fixation of the dye at high temperature, the fabric is in a paste state and the dye in a volatile state, so that it “dissolves” in the fabric & the colour becomes very fast. The penetration becomes so deep that it is difficult to distinguish between the printed fabric side & back side.

The fabric is printed with the following recipe:

5 Parts : Na- Acetate

20 Parts : Citric Acid / (NH4)2SO4

100 Parts : Disperse Dye (liquid form)

175 Parts : Water

700 Parts : Myeprogum / Locust Bean Thickener.

……..1000 Parts

In the paste citric acid adjusts pH between 5.5-6 Na-Chlorate protects the brightness of prints & prevents reduction during steaming.

After printing the fabric is dried carefully & the dye is fixed by one of the following methods.

After thermo fixation of dye, the fabric is washed & reduction cleaning is then carried out. Reduction cleaning is carried out to obtain deep shades. (>5-15%).

Fixation Methods After Printing:-

After printing with disperse dyes the dyes is fixed on the fabric by one of the following dye- fixation methods, namely-

1) Thermo fixation:

2) Super Heated Steaming

3) High Pressure Steaming

Now they are mentioned below:-

1) Themo fixation:-

The features of this method of dye fixation are mentioned below:-

a)No steam is used.

b) Dye is fixed by subjecting the print to hot air at 210ºC for 1 minute.

c) The fixation is carried out in a backing oven or in a stenter where heat setting can also be done simultaneously.

d) The process productivity is high.

e) The dye which have good sublimation fastness are subjected to this thermofixation process.

f) There is 10-15% loss of colour in thermofixation, so the shade becomes dull.

g) It is a continuous process of dye fixation which gives high production.

Super Heated Steaming:

The features of this method of dye fixation are mentioned below:-

1. It is a continuous process of dye fixation.

2.This method is the best of the three methods.

3.Dye is fixed at 1000-1800C for 2-1 minutes by radiators.

4. Higher productivity.

5. No loss of colour.

6.Dyes with medium sublimation fastness can be applied.

7. The fabric handle is very soft.

High Pressure Steaming:

The features of this method of dye fixation are mentioned below:-

A) Discontinuous process of dye fixation

B) Low productivity.

C) Dye fixation is done by high pressure steam.

D) Low production so costly process.

E) Dyes with low sublimation fastness can be applied.

F) It gives good Colour yield and bright.

G) Print & smoothness.

 Reduction Cleaning:

After the fabric is applied dye fixation method it is subjected to reduction cleaning process. Reduction cleaning process is carried out for obtaining deep shade (>5%-15%)

For reduction cleaning a bath is prepred containimg:-

Caustic Soda : 2 gm/litre

Hydrosulphite : 2 gm/litre

Na-ionic Datergent : 2 gm/litre

M : L Ratio : 1:5

Time : 30 Minutes

In the bath caustic soda and Hyd- rosulphite are taken for the stripping of dye and non-ionic detergents is taken for washing off. After passing the printed fabric through this bath then the fabric is washed off, by hot air & then with cold water.

Printing by White discharge Styleon nfixed ground:

In this method the cloth is firstly padded with a disperson of dye containing 2 gm/ litre Na- alginate to reduce the viscosity of the solution & tartaric acid to keep the pH between 5-6. The fabric is squeezed (70% pickup) dried up at 900-1000C.

Then it is printed with a paste containing:

Citric Acid : 30 Parts

Thio-diethylene glycol : 50 Parts

Water : 70 Parts

Safolin : 200 Parts

Locust Bean Gum : 650 Parts

……….Total : 1000 Parts

Here safolin is a reducing or discharging agent, and thio- dietylene glycol is used as a solvent as well as softeners and hygroscopic agents. The fixation is thermofixation process.

Color resist Style of Printing:

At first the polyester fabric is padded in a disperson containing:-

Citric Acid : 5 Parts

Dispersol PC Dye : 50 Parts

Water : 845 Parts

Na- Alginate : 100 Parts

……1000 Parts

Here citric acid controls the pH of the liquor, Na-Alginate act as a binder and water as a solvent.

After padding the fabric is dried at 1000C & printed with the following recipe:

Alkali resist Disperse Dye : 50 Parts

Caustic Soda/Soda Ash : 50 Parts

Glycerine : 100 Parts

Polyetylene Glycol : 102 Parts

Water : 18 Parts

 Mey Progum : 600 Parts

………..1000 Parts

After printing, the fabric is dried at 1100C and steamed for 5 minutes at 1800C with super heated steam.

Printing of Polyester Fabric with Disperse Dyes:

Standard Recipe:

Dyes = 2 parts

Thickener (Na-alginate) = 70 parts

(NH4)2SO4 = 0.7 parts

Dispersing Agent = 2 parts

NaClO3 = 0.2 parts

Water = as required

Procedure:

1) At first a thickener paste is prepared according to the recipe.

2) Then dye and dispersing agent is mixed together.

3) After that ammonium sulphate and sodium chlorate solution is prepared and added together.

3) Then all the solution is added with the thickener.

4)Thus print paste is prepared.

5)The fabric is prepared for printing.

6)!Then the fabric is printed with block and screen method.

7) After printing the fabric is washed well.

Ref:-https:// texilelearner.net.