Q. What is preparation?
Ans: In simple way one can say that the process(s) that can be used to remove impurities from the textile materials (fibre/yarn/fabric/garments) to make them dyeable or printable or any other further use, is called preparation in the chemical processing.

Q. What types of impurities are present in the textile material?
Ans: There are mainly two types of impurities:

• Natural impurities
• Added impurites

Natural impurities: As its heading suggest, the impurities that are present naturally are come under this category. These impurities are present in the natural fibres (Vegetable and animal). Let us take example of Cotton fibre. Following figure indicates the composition of cotton:

From the above figure except cellulose all other constituents are considered as impurities.

To further understand each types of above impurities, let us discuss structure of cotton fibre. Following figure can explain cotton fibre structure:

Q. What is cellulose?

       Ans: It is an insoluble substance which is the main constituent of plant cell walls of vegetable fibres such as cotton. It is polysaccharide consisting of chains of glucose monomers. It is an organic compound with the formula (C6H10O5)n, a polysaccharide consisting of a linear chain of several hundred to many thousands f β(1→4) linked D-glucose unit              

 

          D- Glucose                            β(1→4) linked D-glucose unit