Treatment of cotton with chitosan and its effect on dyeability with reactive dyes

Dyeing behaviour of chitosan pretreated cotton fabric with reactive dyes is the subject of this study. Cotton fabric is treated with chitosan using five different techniques, consisting of exhaustion, pad-dry, pad-batch, pad-steam and pad-dry-steam methods. To find the influence of concentration of chitosan on the dyeability behaviour, different amounts of chitosan were used and the suitable concentration was determined. It is observed that chitosan pretreatment increases the exhaustion of reactive dyes and the highest dye up-take is achieved for pad-dry method. The effect of the period of storage of chitosan treated sample before dyeing process on dyeability of fabrics is examined by comparison of samples which was dyed immediately after treatment with the one which was kept for 48 h after treatment. The results show that dyeing immediately after treatment leads to higher dyeability and the effect of treatment decreases for the samples which were pkept for 48 h before dyeing process. The light and wash fastnesses of treated samples are measured and some reduction in light and wash fastnesses were observed.