Studies on compatibility of selective direct dyes for dyeing of jute fabric

Abstract

Compatibility of binary mixture of direct dyes has been studied by conventional method as well as a new simplified and easier method for application of direct dyes combination on jute, and the findings of both the methods are compared. In conventional method of compatibility test, the study has been made using colorimetric method by comparing ∆C <em>vs </em>∆L and <em>K</em>/<em>S vs</em> ∆<em>L</em> for two sets of dyed samples, varying time and temperature profile in one set, and dye concentration in second set for dyeing jute fabric with binary pairs of dyes in equal proportion (50:50). In proposed method of compatibility test, the colour difference index (CDI) values are calculated for dyed jute fabrics using different proportions of binary mixture of dyes. Finally, from the difference of maximum CDI and minimum CDI, the relative compatibility rating is judged. In conventional method of compatibility test, Direct Red 12B + Direct Green YG and Direct Green YG + Direct T Blue 2R combinations show better compatibility, while Direct Yellow 5GL + Direct T Blue 2R exhibits worst compatibility amongst total six combinations studied. In case of proposed method, Direct Green YG + Direct Yellow 5GL and Direct Green YG + Direct T Blue 2R combinations show better compatibility ; Direct Red 12B + Direct Green YG combination shows fair compatibility ; and Direct Yellow 5GL + Direct T Blue 2R shows moderate compatibility. Thus, the results of two methods though are not exactly the same but are nearer and acceptable.