Characterization and comparison of salt-free reactive dyed cationized cotton hosiery fabrics with that of conventional dyed cotton fabrics

Abstract

Abstract One of the major problems in reactive dyeing of cotton goods is the usage of salt during the dyeing process. The treatment of coloured salt laden effluent is one of the scorching issues in the textile processing house as it significantly increases the cost of the dyed goods. The coloured salt laden effluent generated after dyeing is to be treated by an effluent treatment process before being discharged. Removal of salt from effluent significantly increases the cost of dyed goods. Cationization of cotton is an effective way to eliminate usage of salt in reactive dyeing process. The aim of this study is to carry out industrial scale cationization of cotton hosiery fabrics by exhaust method followed by salt-free reactive dyeing with ultra-deep jet Black dye of shade 9.95%. Fabric without cationization treatment was dyed by conventional dyeing route which involves usage of salt for the same shade percentage. The colour strength of cationized dyed fabric was found to be almost equal to the conventionally dyed fabrics. The total dye fixation (%) of cationized cotton dyed fabric was 58.2%, whereas for conventional dyed cotton fabric it was 51.7%. The effluent parameters of the both routes were compared and it was found that for salt-free reactive dyeing process, the total dissolved solid (TDS) value was four times lower than the conventional dyeing process. Based on the results obtained, the usage of salt can be eliminated for cationized cotton fabric during reactive dyeing process.