Peculiarities in the Apparent Fading Behavior of Some Reactive Dyes in Binary Mixtures

Abstract

This paper deals with studies of the lightfastness of reactive dyes in combination shades. In this work, fifteen commercially available reactive dyes are chosen to obtain both self and binary shades on 100% cotton fabric. Lightfastness of the dyed samples is evaluated by exposing them to a xenon arc lamp using a xenon Weather-O-meter (Atlas S-3000) and assessed subjectively with the Blue Wool Standard. Lightfastness is further confirmed objectively with the help of a spectrophotometer, when the total color difference (CIE-DE) between unexposed and exposed samples is 3.4 or more in CIELAB units. The study reveals that some reactive dyes, when used in combination shades, show lightfastness ratings that are even lower than the lowest values of the individual dyes constituting the mixture.