Vat dyeing of lyocell fabric with high temperature dyeing technique

Successful dyeing of lyocell, a biodegradable regenerated cellulose fiber, in fabric form is still a challenging job. Here in, we report successful dyeing of lyocell fabric with vat dyes by conventional batchwise method. To assess the dyeability of lyocell fabric, a woven lyocell fabric was dyed with three different colorants (Blue Yellow and Red) of vat dyes by using previously determined procedure for vat dyeing on cellulose fabric. Dyeing parameters (temperature and time) were regulated to attain optimal dyeing conditions. Color yield of dyed lyocell fabric was analyzed using Kubelka-Munk equation, and durability of dyed fabric was examined by standard colorfastness properties. Lyocell fabric dyed with vat dyes displayed excellent color strength and remarkable fastness properties under optimized dyeing conditions. SEM results revealed smooth surface morphology after dyeing. The dye effluent analysis showed that dyeing of lyocell fabric with vat dyes is eco-friendly.