Reactive Dyes

Reactive dyes are basically used for dyeing cellulose fibers such as cotton and viscose, but they are more and more gaining importance for wool and polyamide. There is a wide range of reactive dyes is available and enables a large number of dyeing techniques to be used with it. In dyeing cellulose fibers with reactive dyes the following chemicals and auxiliaries are used:

• Sodium carbonate, bicarbonate, and caustic soda

• Sodium chloride and sulphate

• Urea is added to the padding liquor in continuous processes

• Sodium is to be added in the cold pad-batch method.

Direct Dyes

Dyes are water soluble substantive dyes. Dyes cover the entire shade gamut and are easy to apply. They have good levelling property and are cost effective. Dyes for cellulosics possess excellent light fastness properties. Certain dyestuffs within this range are suitable for high-temperature dyeing of cellulosic/polyester blends. In general, they may be applied on cotton by any method and most of the dyes in the range are even suitable for package dyeing of cotton yarn. Dyes can also be used to dye jute and coir.