What are the potential problem caused by acid & alkali in textile wet processing?

PROCESS	Problem
1. Desizing	De-active enzymes & insolubility size mtls, such as starch, PVA etc.
2. Scouring	Combine with soap, precipitate metal organic acids. Produce yellowing or off-white shades, reduce cleaning efficiency & reduce water absorption.
3.Bleaching	Decompose bleach bath. H2O2 → H2O + [O]
4. Mercerizing	Form insoluble metal acids, reduce absorbency & luster.
5. Dyeing.	Combine with dyes, changing their shades, insolubilize dyes, cause tippy dyeing & reduce dye diffusion.
6. Printing	Break emulsion, change thickness, efficiency & viscosity, Combine with dyes, changing their shades, insolubilize dyes, cause tippy dyeing & reduce dye diffusion.
7. Finishing	Interfere with catalysts, cause resins & other additives to become non-reactive break emulsion & de-actives soap.

Describe the effects of hard water in textile wet processing? | State the disadvantages of hard water?

1) SCALE FORMATION:

If hard water is used in boiler, then a layer is formed on the inner surface of the vessel or in the inner side of tube. This layer is very hard just like as stone which is not removed without hammer or chaser or tassel. This is called scale.

In boiler, temporary hard water produce CaCO3 & Mg (OH)2. The combination of CaCO3 & Mg(OH)2 is called scale.

Ca(H CO3)2 ∆→ CaCO3 ↓ + CO2 ↑ + H2O

Mg(H CO3)2 ∆→ Mg CO3 ↓  + CO2↑ + H2O

Mg CO3 + H2O ∆→ Mg(OH)2 + CO2↑

CaCO3 + Mg(OH)2 → Scale.

Process sequence of wet processing For knit fabric?

Define wet processing? | Its main divisions? | Process sequence of wet processing technology?

The process by which the textile materials are treated associated with water is called wet processing.

There are mainly 3 (Three) divisions of wet processing:-

’1)Pretreatment: The processes, which are done to make the textile materials, suitable for dyeing & printing, are called pre-treatment, Such as- DE sizing, Scouring, Bleaching etc.  

‘2) Dyeing & printing: The process by which the textile material are colored by different types of dye or pigments, related chemical related chemicals required water is called dyeing. Localized application of dyestuff or pigments on fabric according to the pre-determined design is called printing.