OPTIMIZATION OF REACTIVE DYEING PROCESS FOR CHITOSAN TREATED COTTON FABRIC

The colour of textiles plays an important role in the marketability of fabrics, due to its psychological and eye-catching effects on consumers. Synthetic dyes are widely used in the textiles industry due to their ability to reproduce different colours and shades, easy application method and huge production to fulfill the demands of ever-increasing population. Reactive dyes are most commonly used for cotton fabric, due to their brilliant colours and good washing fastness. However, the major problem with reactive dyes is that they consume huge amounts of alkali or salts as mordant for the fixation of dyes on cotton fabric. Most of the commercial dyeing units and textile export houses have started seeking possibilities to use safe synthetic dyes for dyeing different textiles for targeting the niche market. For that purpose, appropriate standardized scientific dyeing techniques and procedures need to be adopted. In the present study, the use of chitosan as mordant, instead of alkali or salt, was investigated for dyeing cotton fabric with reactive red dye, and the dyeing variables were optimized to attain the maximum colour strength value. The results of study showed that higher percent dye absorption (78.90%), colour strength (18.72) and good wash fastness rating (4/5) were achieved for the chitosan treated dyed fabric, compared to the alkali treated dyed sample (68.36% and 13.03, respectively).