What Are The Types Of Dyes?

Dyes are basically classified into seven broad categories, namely acid dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, sulphur dyes and vat dyes.

Acid dyes are water-soluble anionic compounds. Basic dyes are water-soluble dye. They are usually applied in weakly acidic dye-baths. They are very bright dyes. Direct dyes are water-soluble anionic compounds. They can be applied openly to cellulosics without using mordants or metals like chromium and copper.

Disperse dyes are not water-soluble. Reactive dyes are the largest class of dyes. They are water-soluble anionic compounds. Sulphur dyes are organic compounds containing sulphur or sodium sulphide. Vat dyes are the oldest variety of dyes. They are also chemically the most complex variety of dyes. They are water-insoluble dyes.

There are four methods used for the production of each of these dyes, namely exhaust, beck, continuous and cold bad patch. Reactive dyes can be produced using all the four methods.        

Categories of acid dyes