Research on reuse of standing dye bath of reactive dye

Abstract

The aim of the work was to find out suitable method of dyeing so that costly reactive dye bath can be reused without draining them. Because of the hydrolysis of residual reactive dyes due to the fixation conditions and because of relatively large amounts of dyes and salts left in the effluent, reusing hydrolyzed reactive dyes is a challenge to dyers. Two reactive dyes were examined (reactive red, reactive yellow and two fabrics: nylon, silk as well as silk fiber and nylon yarn). When using suitable dyeing conditions by controlling pH and temperature, hydrolyzed reactive dye baths for silk and nylon dyeing showed very good wash and moderate colorfastness.