ABSTRACT
Abstract: Sulphur dyes are exclusively used in dyeing of cellulosic with deep black, navy blue, khaki, green and a few other shades at remarkably cheaper price along with excellent colour fastness except against chlorine. Sulphur dyes are nonionic and are applied in reduced and solubilised anionic state succeeded by oxidation to restore parent non-ionic dye structure when sulphur dye-cellulose physical attachment is established along with aggregation in situ. Produced shades lack tinctorial brilliance which may be modified by topping while brilliant red, orange and yellow are the limitations in this class. Excess free sulphur in dyed cellulose is liable to damage cellulose in moist atmosphere during storage forming tiny holes. Sodium sulphide – the most effective reducing cum solubilising agent – pollutes wastewater and corrodes concrete discharge pipes.
