Improvement in Dyeability of Nylon 6 Fibers Using Lipase Enzyme

This study was carried out to improve nylon 6 fiber structure and to study different properties including dyeability, moisture absorption, surface changes and color fastness using lipase enzyme. For this purpose, nylon 6 fabrics were first treated with different concentrations of lipase enzyme in water solution including 1, 2, 4 and 6% o.w.f. The dyeing process was then carried out on the treated fabrics with disperse and acid dyes. The results of color measurement on enzyme treated/dyed with these two class of dyes showed that the L* of enzyme treated samples decreased and more decrease in L* was observed with an increase in the enzyme percentage. The results of acid and disperse dyes exhaustion on treated fibers showed higher absorption of dyes on fibers. Tensile strength studies indicated that enzymatic processing decreases tenacity, modulus and elongation at break of nylon 6 fabric. Thermal studies of enzyme treated sample did not show significant changes on orientation of fiber after enzyme treatment before the temperature of 300˚C. But increase in heating temperature of the sample to the range of 300-400 ˚C showed considerable decrease in thermal degradation temperature of enzyme treated sample compared to non-treated one. The wash and light fastnesses properties of samples were measured according to ISO 105-CO5 and Daylight ISO 105-BO1, respectively. Enzyme treatment before dyeing process improves wash and light fastnesses of samples which could be the result of dyes penetration into the fibers.