Oxidative clearing of polyester and post-bleaching of cotton : a novel shorter process with better fastness

Abstract

An oxidative clearing process for disperse dyes with hydrogen peroxide was applied, replacing a process that is usually applied, which is the reduction clearing done with sodium hydrosullphite. This is a very polluting process due to the high values of COD and conductivity obtained as a result of its application. An oxidative process is a more sustainable process, saving in water, by avoiding intermediate rinsing, and it less polluting by not using reducng agents and by using less alkaline conditions. It can also bleach the cotton component in PE/CO blends dpending on the peroxide used and the alkalinity of the liquor.