Introduction of printing in Textile
Introduction of printing :
Textile printing is a kind of localized dyeing that is dyes or pigments are applied locally or discontinuously to produce various design on textile fabric with a motif or motives in one more colors.
Also can be defined as : 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 .
Steps in Textile printing :
1.Grey textile raw materials
2.preparation of textile materials (Singeing , desizing , bleaching, scouring )
3.Preparation of printing paste
4.Printing with a certain style and method
5.Drying of the printed goods in dryer method
6.Steaming of the printed fabric (to transfer dye into fiber, 100-102 degree centigrade , 15 minutes as steamer .
7. After treatment (Soaping and washing )
Various design:
Natural item for print effect :
1. Flowers
2. Leaves
3. Fruits
4. Natural beauty
5. Animal print
6. Cats
7. Dogs
8. Tigers
9. Lion
10. Various birds
Artificial :
1.Mental creation
2.CAD
Printing ingredients :
There are some ingredients used to print of textile materials that are given below -
1.Dyes /Pigments
2.Wetting agent
3.Thickener
4. Solvents / Dispersing agents/Solution acids
5. Defoaming agent
6. Oxidizing and reducing agent
7. Catalyst and oxygen carrier
8.Acid and alkalis
9.Carrier and swelling agent
10.Misc agents
Function of Printing ingredients are given below :
1.Dyes /Pigments :
a)Attraction of dye stuff to textile fiber due to the presence of auxochrome
b)To achieve color effect on the textile material
c)To produce required shade
Example : Vat , Reactive and Direct .
2.Wetting agents :
a)To wet fabric as well as dyes
b)To reduce surface tension of water allowing the dyestuff for easy penetration into fibers.
c)To obtain smooth paste
d)To dissolve dyestuff in the paste
Example : Olive Oil , TR oil , Castor Oil
3.Solvents/Dispersing agents /Solution acids :
a)Make design brightness
b)Assist dye penetration
c)Assist dye fixation
d)prevent precipitation
e)To increase solubility of the dyes
f)To make proper printing shades
g)To spread dye molecules evenly in the paste
Example : Glycerine , Alcohol, Acetone , Di-methylene glycol.
4.Thickener functions :
a)To give required viscosity of the printing paste
b)to prevent premature reactions between chemicals in the printing paste
c)To hold the ingredients of the printing paste on the fabric .
Example : Na –Alginate , Fine gum , British gum .
5.Defoaming agents :
a)To prevent the foam generation during printing process
Example : Silicone , Defoamers , Sulphated oils , Perminol KB, Emulsified pine oil
6.Oxidizing and reducing agents:
Oxidizing agents functions:
a) Help to dye fixation
b)It helps to develop final color during steaming or subsequent after treatments.
For example : Potasium chlorate , Sodium Nitrate , Sodium chlorate , Resist salt , Amonium Chloride , Ludigol , Na or K dichromate .
Reducing agents :
a)Use for reduction of different dyes
b) Used for mainly in discharge print
c)To destroy color from the ground of fabric
d) To make insoluble dye to soluble
Example : Sodium hydro-sulphite , Stanus chloride , Rongolite –C
7.Catalyst and Oxygen carrier :
a)To prevent fiber damage during steaming
b) Accelerate the final color development by oxidation
c)Reduce the risk of oxidization
Example : Copper Sulphide , Ammonium vanadate , Potasium ferrocyanide
8.Acids/Alkalies :
a) To maintain PH
b)To develop the color of printed fabric
c)Dye fixation permanently
Examnple : KOH, NaOH, Na2CO3
9.Carrier and Swelling agents :
a) To create big size hole of the fiber
b)Helps to swell the fiber structure
c)To reduce crystallinity
d)helps to easy penetration of dye molecule inside the fiber polymer .
Example : polyethylene glycol , Phenols ,
10.Misc Agents :
a)Hygroscopic agents
b)Fixation of dyes
c)Absorb moisture from air
d)facilitate subsequent washing off
Example : Urea , Glycerine