Basic concept and Objects of Dyeing

Dyeing :

The process by which a textile material is to be changed physically or chemically, so that it looks mono uniform colored is called dyeing. All commercial textile dyeing processes take place by the application of a solution or a dispersion of the dyes to the textile material followed by some type of fixation process. The dye solution or dispersion is almost always in an aqueous medium. A major objective of the fixation step is normally to ensure that the coloured textile exhibits satisfactory fastness to subsequent treatment in aqueous wash liquors. Dyeing is mainly depends on the type of fabric, structure of fabric and the properties of dyes.

Objects of Dyeing:

1. The textile goods are dyed uniformly with single color.
2. To increase the attractiveness of the textile goods.
3. To make the fabric suitable for various usages.
4. To make the textile goods suitable for decorative purposes.

Theory of Dyeing:

The procedure by which dye stuff enters into the textile goods is called theory of dyeing.

It is essential to have certain degree of fastness properties when a dye particle is applied

on textile goods.

The whole process of dyeing is completed by four steps as follows:

1. Dye molecules come to the fabric surface from the dye bath.

2. Fibre absorbs the dye molecule from the outer surface of the fibre to the internal

surface of the cellulose.

3. Migrates the dye molecules everywhere of the fibre molecules.

4. Anchoring or fixing the dye molecules to the fibre molecules by hydrogen or covalent

bond.