Acid dyes are a class of water-soluble dyes that contain acidic functional groups in their structures. The most of acid dyes exist in the form of sodium sulfonate salts, with a few in the form of sodium carboxylate salts. Initially, these dyes were used for dyeing under acidic conditions, hence the name "acid dyes."

Acid dyes are the largest category of dyes and are mainly used for dyeing and printing wool, silk, and other protein fibers, as well as polyamide fibers. They can also be used for coloring leather, ink, paper, cosmetics, and food colorants. Acid dyes have low direct affinity for cellulose fibers, with only a few structurally complex dyes being able to dye cellulose fibers.

Acid dyes are characterized by their complete chromatography and bright colors. However, their wet processing fastness and light fastness vary greatly depending on the dye variety. with those containing simple structures and more sulfonic acid groups exhibiting poor wet processing fastness.

Classification of Acid Dyes(Application Classification)

Based on dyeing properties and applications, acid dyes can be classified into three types: strong acid bath, weak acid bath, and neutral bath.

Application of Acid dyes

1. Exhaust dyeing

2. Jig dyeing

A. ACID LEVELING AGENT....................................................1-3%

   FOAM SUPPRESSOR AND WETING AGENT ...................0.2-0.5(G/L)

   AMMONIUM SULPHATE................................................1-2(G/L)

B. DYESTUFFS......................................................................X%

C. WASHING