Direct Style of Printing on 100% Polyester by Varying the Print Fixation Methods

The Direct Style of Printing on 100% Polyester by Varying the Print Fixation Methods

Rushikesh Digambar Patil
Department of Textiles (Textile Chemistry)
DKTE’S Textile & Engineering Institute, Ichalkaranji, India
Intern at Textile Learner
Email: rushikeshpatil23052002@gmail.com

 

Introduction:
In the textile business, polyester fabrics play a significant role. The most suited dyes for printing on Polyester fiber materials are dispersed dyes, which produce prints with excellent overall fastness. Disperse dyes have a substantially higher washing fastness on polyester than acetate, triacetate, or nylon. They have a great dispersing capacity, making them easy to scatter in water. Various fixing procedures for dispersed dyes are listed below-

  1. Atmospheric steaming
  2. High temperature steaming
  3. Pressure steaming
  4. Thermofixation method

It’s crucial to choose the right dispersion dyes and thickeners. Dyes with low sublimation fastness can be utilized for air steaming and pressure steaming. Dyes with a medium to moderate sublimation fastness can be used for HT steaming, whereas dyes with a high sublimation fastness can be utilized for thermofixation.

Different Print Fixation Methods:

Atmospheric steaming Pressure steaming High temperature steaming Thermofixation
Conditions-

1) Temperature = 102 to 105°C

2) Carrier is added

3) Time = 30 min

Conditions-

Temperature = 125 to 130°C

Pressure = 1 to 2 bar (25-30 psi)

Time = 30 min

Conditions-

1) Temperature =165 to 180°C

2) Time =5 to 20 min

Conditions-

1) Temperature =200 to 210°C

2) Time=120 to 130 seconds

Steam- Saturates Steam Steam- Saturated Steam Steam- Supersaturated Steam- Supersaturated
a) Machine= Loop ager

b) Continuous process

a) Machine= Star ager

b) Continuous process

a) Machine= HT steamer

b) Batchwise process

a) Machine= Stenter

b) Continuous process

[Notes-

  • Saturated Steam: Once the water is heated to the boiling point, it is vaporized and turned into saturated steam It has moisture.
  • Supersaturated Steam: When saturated steam is heated above boiling point, dry steam is created and all traces of moisture are erased. This is called superheated steam. It doesn’t have moisture]

Mechanisms of Different Print Fixation Methods:

A. Atmospheric steaming:
For 30 minutes, the fabric is held at 102-105°C for atmospheric steaming. We should include a carrier in the solution that causes the fiber to expand, allowing dyestuff molecules to easily permeate through it.

Because carrier dye can enter into the fine structure of polyester and push adjacent long-chain molecules apart, the molecular pattern loosens up, resulting in a lower (Tg) glass transition temperature of polyester. As a result, segmental vibration increases, allowing large dyestuff molecules to enter the polyester structure and disperse dye to become mechanically trapped.

B. Pressure steaming:
The segmental vibrations increase and the glass transition temperature (Tg) decreases at such high temperatures and pressures. Long chains are pushed apart by this segmental vibration. Also, at such high pressures of 1 to 2 bar or 25 to 30 psi, dye penetration occurs under high temperature because the temperature drops after 30 minutes, and the dye particles become physically stuck inside the polyester framework.

C. High temperature steaming:
The temperature of the steam is excessively high, resulting in more and more segmental vibrations. As a result, the dye can permeate the fiber structure and is mechanically trapped after 20 minutes of supersaturation. Because steam is used, moisture is present; therefore, we add urea as a hygroscopic substance to enhance moisture.

D. Thermofixation:
Polyester melts at 230°C, hence its softening temperature is 200 to 210°C. At such high temperatures, such as 200 to 210°C, polyester becomes weakened around its melting point, and color particles diffuse inside polyester, attempting to become a part of polyester that cannot be separated.

Style of printing: Direct style.

Method of printing: Screen-printing method

Preparation of thickener – [Thickener (5 %)]

We have to prepare a 5 % thickener

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Recipe:

Thickener paste (100 gm)

Thickener Powder: 5-6 gm
Water: 94-95 ml
———————————————————
Total    100 gm

Screen printing method:

  1. The fabric is placed on the flat surface of the table, which is composed of soft material.
  2. The screen is then placed on the cloth sample.
  3. The printing paste is applied to the perforation on the screen.
  4. With a smooth wooden strike, the paste is distributed over the screen with light pressure, allowing us to locate the printed cloth. So that the dye particles can pass through the perforation in the screen.
  5. As a result, we have printed fabric.

Procedure:
1. Prepare the print paste as per the below recipe-

S/N Parameters Atmospheric steaming Pressure steaming High temperature steaming Thermofixation
1 Temperature 102-105°C 125-130°C 165-180°C 200-210°C
2 Time 30 min 30 min 5-20 min 120-130 sec
3 Pressure 1-2 bar
Ingredients Quantity
1 Disperse dye 3-5 gm 3-5 gm 3-5 gm 3-5 gm
2 Urea —– —- 2 gm 2 gm
3 Carrier 1 gm
4 Acid donar 1 gm 1 gm 1 gm 1 gm
5 Water 5-10 ml 5-10 ml 5-10 ml 5-10 ml
6 Sodium chlorate 1 gm 1 gm 1 gm 1 gm
7 Thickener 85-90 gm 85-90 gm 80-85 gm 80-85 gm
Total 100 gm 100 gm 100 gm 100 gm

The process sequence for different print fixation methods:

Atmospheric steaming Pressure steaming HT steaming Thermofixation

Printing

Drying

Atmospheric steaming at 102-105°C for 30 min

Wash

Reduction cleaning at 60°C

Wash

Drying

Printing

Drying

Pressure steaming at 125-130°C & 1-2 bar pressure for 30 min

Wash

Reduction cleaning at 60°C

Wash

Drying

Printing

Drying

HT steaming at 165-180°C for 5-20 Mini

Wash

Reduction cleaning at 60°C

Wash

Drying

Printing

Drying

Thermofixation at 200-210°C for 120-130 sec

Wash

Reduction cleaning at 60°C

Wash

Drying

2. Print the given polyester fabric sample with the above recipe

3. Dry the sample at 80°C

4. Carry out fixation by following methods:

  • Atmospheric steaming: at 102 to 105°C for 30 minutes
  • Pressure steaming: at 125 to 130°C for 30 minutes at 25 psi in a pressure steamer.
  • High Temperature steaming: at 180 0C for 7-8 minutes in a superheated steamer.
  • Thermo fixation- at 200-210°C for 30-60 seconds on stenter.

5. Rinse the fabric samples with warm water after fixation and perform a reduction clearing procedure at 60°C for 20 minutes using 2 GPL NaOH and 2 GPL Hydros.

6. Wash the sample with hot, cold, and dry water after this treatment.

Advantages & disadvantages of the process:

Atmospheric steaming Pressure steaming HT steaming Thermofixation
Advantages-

1. Disperse dye with low sublimation fastness can be used

2. This process has a High production rate

3. It is a continuous process

4. Bright prints with full-color yield can be

Advantages-

1. Disperse dye with low sublimation fastness can be used

2. No carrier we used

3. Bright prints with full-color yield can be

Advantages-

1. This process has a High production rate

2. It is a continuous process

3. Bright prints with full-color yield can be achieved

4. No Carrier is used

Advantages-

1. This process has a High production rate

2. It is a continuous process

3. No carrier is used

Disadvantage-

1. Carrier is required

2. Time consuming process

Disadvantage-

Lowest production rate

Required special machine

Disadvantage-

1. Low sublimation fastness Disperse dye can’t be used

2. Require special machine for high temperature

Disadvantage-

1. Low sublimation fastness Disperse dye can’t be used

2. Prints are not bright

3. 10-15% color yield is lost due to high temperature

Resultant samples fixation methods are:

Atmospheric steaming

pressure steaming

Thermofixation

Conclusion:
Above all these print fixation methods, the pressure steaming method gives the brightest prints. Every method has its advantages as well as disadvantage so, as per requirement we can produce prints with different methods.

You may also like:

  1. Pigment Printing on Polyester Cotton (P/C) Blended Fabric by Using the Direct Style of Printing
  2. Printing of P/C Blended Fabric Using Disperse-Reactive System

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