What is dyeing

Ans.: Dyeing is a distribution process in which dye-pigment is distributed into two phases or phase system that is the dye/ pigment solution or bath and the textile materials.

Fastness of dyes

The capacity of a dye on a textile material (after dyeing) to resist a bad or destructive factor is referred to as fastness.

There are various types of fastness of a dye on the textile materials, such as:

(1)  Color Fastness to light

(2)  Color Fastness to wash

(3)  Color Fastness to rubbing (dry + wet)

(4)  Color Fastness to perspiration

(5)  Color Fastness to hot pressing

(6)  Color Fastness to water (hot)

(7)  Color Fastness to acids

(8)  Color Fastness to alkalis

(9)  Color Fastness to solvents

(10)     Color Fastness to weathering

(11)     Color Fastness to gases

(12)     Color Fastness to bleaches

(13)     Color Fastness to oxidizing and reducing agents. etc

Textile dyes:

Dyes are coloring unsaturated organic substances have been used for the coloration of textile materials. Most of the dyes are water soluble. A dye molecule consists of there 3 parts such as:

(1)    Chromophore groups - Color bearing part or group of dye molecule

(2)    Auxochrome groups - Color helping group which determines the properties of dyes

(3)    Chromogen groups - Hold the structure of dyes