Simultaneous dyeing and finishing of cotton fabric using reactive dyes and citric acid

The efficacy of concurrent dyeing and finishing of cotton fabric with reactive dyes and citric acid has been studied. Factors affecting the process, such as alkali concentration and catalysts, were examined in two different process routes, i.e. simultaneous alkali addition and after development with alkali, for two dyes concentrations. Control samples were prepared by conventional two-step method. Evaluation of the simultaneously dyed and finished (SDF) fabrics was made with respect to colour strength (K/S), crease recovery angle (CRA), tensile strength and fastness properties, and the findings were compared with control samples. It is observed that the SDF fabric gives better K/S, CRA, tensile strength as well as fastness properties as compared to control samples; K/S and CRA increase with the increase in alkali concentration, whereas tensile strength decreases. Catalyst sodium hydrosulphite is found to give better overall results than sodium dihydrogen phosphate in case of SDF method as well as in control samples.