Here are the answers to the problems: 1. Textile printing is the localized application of dyes or pigments and chemicals by any method which can produce particular effect of color on the fabric according to the design. 2. I have already stated the functions of different print paste ingredients with examples in the previous content. 3. The various stages of textile printing are: fabric preparation, design selection, print paste preparation, printing, drying, steaming, washing and soaping, and final drying. 4. Oxidizing agents assist dye fixation and color development during steaming. Alkalis help develop and fix dyes permanently on the fabric. Urea absorbs moisture from air and assists dye fixation.

1. Mohammad Shohag
Lecturer, DoWPE
BUTEX
Email: sheikhshohagtex@gmail.com
WPE: 311
Wet Processing- II
Part-A: Textile Printing

2. Curriculum Details
- Credit of the course is 3.
- Hour/Week 4.
- Total Week 10.
- Total Hour 40 (Part-A 20 Classes & Part-B 20 Classes).
Part A(Textile Printing) Part B(Textile finishing)
1. Introduction to Printing.
2. Thickener
3. Style of Printing.
4. Printing Methods/techniques
5. Special printing method.
6. Printing with different
dyes/pigment
1. Introduction to Finishing.
2. Physical or Mechanical Finishing.
3. Chemical Finishing.
4. Special Finishing.
Part A: Mohammad Shohag
Part B: Humayra Akhter Himu

3. MARKS ALLOCATION
1.CLASS ATTENDANCE =8
2.CLASS TEST (5×4) =20
3.FINAL =72(Part A-36, Part B-36)
TOTAL =100

4. 1. Textile printing by Leslie W C Miles.
2. Principle of Textile Printing by Asim Kumar Roy Choudhury
3. Technology of Printing edited by Prof. V. A. Shenai.
Reference Book:

5. Chapter-1: Introduction to Printing

6. Table of Contents
• Definition of Printing
• Objectives of printing
• Difference between dyeing and printing.
• Chronological development of Printing machinery
• History of printing
• Steps of textile printing process using dye
• Functions of print paste ingredients with example.

7. What is Textile Printing?
Textile printing is the most versatile and important of the methods used for
introducing color and design to textile fabrics. The term ‘’textile printing’’ means
the localized application of dyes or pigments and chemicals by any method
which can produce particular effect of color on the fabric according to the
design.
In printing dye/pigment and chemical are applied in paste form, this paste are created
with dyes/pigments, thickener, other necessary chemicals etc.
Printed fabric can be identified by looking at back side of fabric where there is no design
or color as face side.

8. Objectives of Printing
⮚ To add color on localized area.
⮚ To produce various attractive designs.
⮚ Allows greater design flexibility over other system.
⮚ Inexpensive product compared to other system.
⮚ Combines art, engineering, and dyeing technology to produce images
that existed only in the textile designer’s mind.

9. Block Printing Technology

10. Roller Printing Technology

11. Screen Printing Technology

12. Transfer Printing Technology

13. Digital Printing Technology

14. Chronological Development of Textile Printing Machine
Method Period Origin
Block Ancient China
Roller printing 1785 Scotland
Manual Screen 1900 England
Auto flat bed Screen 1940 Switzerland
Rotary Screen 1963 Portugal
Transfer Printing 1968 France
Inkjet/Digital printing 1990 USA

15. Historical Perspective of Textile Printing
• Fabric printing is not a new process; in fact, it’s been around for many
centuries. Ancient civilizations used color and design to set themselves apart.
• Textile printing is an ancient art, from the 4th and 5th centuries BC. The first
commonly used textile printing method originated in China, where examples of
wooden block printing have been discovered.
• Block printing is the process of designing fabric using some form of carved
material generally been wood or copper, but on occasion rubber and even other
materials have been used, and are still using today.
• At the beginning of the 17th century, the East India Company began to ship block
printed cotton fabric to England. But they unable to produce the designs demanded
by British, so British people implement printing in their places with their own specific
patterns, It was near about 1676 they established the first print works in
England, near London.

16. Historical Perspective of Textile Printing
• Later, in the 18th century (near about 1785), a printing technique using rollers or
cylinders emerged. This is a process whereby the fabric is carried along a rotating
central cylinder and pressed by a series of rollers, each of which is engraved with
the design. Each roller is supplied with a different color through the feed rollers, and
some roller printing machines were able to print as many as 6 colors at a time,
making them much faster than the block printing process.
• The 20th century marked the arrival of the modern silk-screen printing process. In
the mid-20th century, multi-color rotary screen-printing enabled screen
printing on a large scale and at a faster rate, making it more economical.
• In 1750s Transfer printing invented for decorating pottery or ceramic items. In the middle
of 20th century it becomes enormously popular in other sectors like textiles, home album,
tourism etc.
• Today, we have digital textile printing, which uses computer-controlled lasers to
inject the ink directly into the fabric. This allows the printing of very detailed
designs extremely quickly and efficiently.

17. Printing
Dyeing
Steaming is not required on dyed fabric
Steaming is used in the printed fabric for
fixation
More time is required Less time is required
Whole fabric is uniformly covered with
one color
One or more colors are applied only to
defined areas to obtain the desired pattern.
No use of thickener Thickener is used
Huge amount of water is required Less amount of water is required
Fiber, yarn and fabric are dyed
Mostly fabric is printed but now a days yarn
are also printing.
Dyeing is a thorough coloration process of
textile materials in which dyes and pigments
are applied from a solubilized medium to the
textile materials.
Printing is the localized application of dyes and
pigments from a solubilized or a insolubilized
medium to the fabric surface.
Color is applied in form of solution Color is applied in form of thick paste
1
2
3
4
5
6
7
8
Difference between Dyeing and Printing

18. Grey Fabric
Preparation of Fabric
Design Selection
Preparation of print paste
Printing on the fabric by block, roller, screen
Drying of printed fabric
Steaming of printed fabric
Washing and Soaping
Final dry
Steps of Textile Printing Process
Artworks received from
buyer to follow design
Design transfer to
blocks/rollers/screens
manually or by exposure
of light sensitive coating
Color Separation

19. 1. Dyes or Pigments
2. Thickener
3. Wetting agents
4. Solvent/dispersing agents
5. Defoaming agents
6. Oxidizing agents
7. Reducing agents
8. Catalyst and oxygen carrier
9. Acids and Alkalis
10. Carrier
11. Swelling agents
12. Hygroscopic agents
Functions of print paste ingredients with example.

20. 1. Dyes or Pigments:
⮚Produce color effect on the fabric
⮚Achieve required shade
⮚Attraction of dyes to the fabric due to presence of auxochrome.
Example: Direct dyes, Reactive dyes, Vat dyes, Acid dyes, Basic dyes, Disperse
Dyes, Azoic dyes and Pigments.
2. Thickener:
⮚ To give required viscosity to the printing paste.
⮚ To prevent premature reactions between the chemicals contained in the print
paste.
⮚ To hold the ingredients of the print paste on the fabric.
Example: Starch, Na-Alginate, Guar gum, British gum, Locust bean gum, Gum
arabic, Gum tragacanth, CMC(carboxy methyl cellulose) etc.
Functions of print paste ingredients with example.

21. 3. Wetting Agents:
⮚ To reduce the surface tension of water allowing the dyestuff for easy penetration
into fabric.
⮚ To wet the fabric as well as dissolve the dyestuff in the paste.
⮚ To obtain smooth paste
Example: Turkey Red Oil(T.R Oil), Olive oil, Castor oil, Glycerin, Almond oil,
Lissapol N. animal oil etc.
4. Solvents or dispersing agents:
⮚To prevent aggregation of the dye molecules in the highly concentrated paste.
⮚To spread dye molecules evenly in the paste.
⮚To increase solubility of the dyes.
⮚To get bright and prominent print design.
Example: urea, Glycerin, di ethylene glycol, thio diethylene glycol, acetone, alcohol.
Functions of print paste ingredients with example.

22. 5. Defoaming agents:
⮚To prevent the foam generation during printing.
⮚To make proper printing shade.
Example: Silicone defoamers, Sulphated oil, Perminal KB, Emulsified pine oil.
6. Reducing Agents:
⮚To make the insoluble dyes to soluble form.
⮚Used for reduction of different dyes.
⮚Used mainly in discharge style printing.
⮚To destroy color from the ground of fabric.
Example: Rongalite C, sodium hydrosulphite..
7. Oxidizing agents :
⮚ To develop the final color during steaming or in the after treatment.
⮚ To assist dye fixation.
Example: Potassium chlorate, sodium chlorate, sodium nitrate, Na or K dichromate,
ammonium chloride etc.
Functions of print paste ingredients with example.

23. 8. Mild Oxidizing agents:
⮚In case steaming of azo dyes, the prints tends to reduce which may result in loss of color value and
destruction of dyes, to prevent this problem mild oxidizing agents are used.
Example: Ludigol, Resist salt.
9. Catalyst and Oxygen Carrier:
⮚ To prevent fiber damage during steaming.
⮚ Accelerate the final color development by oxidation.
⮚ Reduce the risk of oxidation.
Example: Copper sulphide, Potassium ferrocyanide, ammonium vanadate.
10. Acids and Alkalis:
⮚ To maintain PH
⮚ To develop the color on fabric
⮚ To fix dyes on fabric permanently
⮚ To fix pigments and binders on fabric permanently.
Example: Acids- organic acid, ammonium chloride, diammonium hydrogen phosphate,
ammonium sulphate, ammonium nitrate etc.
Alkalis- sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,
sodium bicarbonate, sodium silicate, trisodium phosphate, di sodium hydrogen phosphate.
Functions of print paste ingredients with example.

24. 11. Swelling agents:
⮚Helps to swell the fiber structure.
⮚To increase the intermolecular space of fiber.
⮚Helps to penetrate the dye molecule inside fiber space.
Example: Phenol, polyethylene glycol, Diethylene glycol diacetate(DEGDA), Ethyl
lactate[CH3CH(OH)COOC2H5].
12.Carrier:
⮚Works like swelling agents.
⮚Lowering the glass transition temperature(tg) thus promote molecular chain movement
and create free volume.
Example: phenol, ortho phenyl phenol, para phenyl phenol, dichloro benzene.
13.Hygroscopic Agents:
⮚ Absorb moisture from air.
⮚ To assist dye fixation.
⮚ Facilitate subsequent washing off.
Example: Urea, Glycerin etc.
Functions of print paste ingredients with example.

25. Problems:
1. What is textile printing?
2. State the functions of different print paste ingredients with example.
3. Write down the various stage of textile printing.
4. Mention the functions of oxidizing agent, alkali and urea in a print paste.
5. Differentiate between dyeing and printing.
6. Mention the functions of defoaming agents, hygroscopic agent and dispersing
agent in a print paste.
7. Mention the chronological development of printing era.