SulfurDyes

Uses

Sulfur dyes are applied to cotton from an alkaline reducing bath with sodium sulfide as the reducing agent. These dyes are water-insoluble but they are soluble in their reduced form and exhibit affinity for cellulose. They dye by adsorption; but on exposure to air, they are oxidized to reform the original insoluble dye inside the fiber. The cost is low and they have good fastness to light, washings, and acids.