Innovative Approach for Effecting Improved Mordant Dyeing of Cotton Textiles

BLEACHED cotton fabrics were submitted to successive treatments, Viz., UV/O-3 irradiation and chitosan treatments. Thus obtained irradiated-chitosan treated fabrics form the base of innovations whereby high improvement in mordant dyeing as well as in antibacterial activity of the cotton fabrics could be achieved. Mordant dyeing was performed as per three methods: 1) Premordanting where the irradiated-chitosan treated fabric was mordanted prior to dyeing. 2) Meta-mordanting involved conducting dyeing to a mid-way point at which the mordant was added and dyeing continued till completion; and 3) Post-mordanting refers to complete dyeing followed by mordanting of the dyed fabric in a separate step. Two natural dyes, namely, curcumin and hibiscus were used. Mordants used were zinc acetate and cadmium acetate. As envisioned the UV/O-3 irradiation of cotton fabric causes profound changes in the physical and chemical structure of cotton. These changes are ameliorated by further treatment of the irradiated fabric by chitosan. UV/O-3 irradiation in combination with chitosan treatment plays a significant role in the mode of interactions of cotton with the mordant as well as with the dye itself during mordant dyeing.