Single-bath-single-stage enzymatic treatment of denim

Abstract

Denim has been a popular choice of apparel worldwide, prized for its versatility and long-lasting qualities. Being a core part of fashion trends for ages, a variety of techniques are being introduced in the denim industry to create a diverse and aged look. This research investigates the application of a combination of amylase, cellulase, and laccase at different temperatures on denim to achieve desired aged or faded appearance. The samples from 9 different washing recipes were analyzed properly for tensile strength, seam strength, color changes, back staining, stiffness, and chemical oxygen demand (COD). The results led to the finding of an optimal washing condition. An aged look on denim fabric can be varied by varying washing temperatures and amounts of laccase enzyme. The highest fading of denim garment was obtained when washed at a temperature of 65 °C for 45 min using 1.5 g/L of amylase, 1.5 g/L of cellulase, and 2 g/L of laccase enzyme. This was confirmed by the lowest whiteness index of the pocketing fabric (70.1) with an improved fabric feel as evident from the lowest bending length of 2.254 cm. The enzymatic process was found to be significantly environment-friendly as generated wastewater required almost 4 times less oxygen to degrade than the wastewater from the conventional process. Notably, this temperature selection did not negatively impact the fabric's tensile strength and abrasion resistance, emphasizing the efficiency of enzymatic processes. It further strengthened the position of single-bath-single-stage enzymatic treatment of denim as an alternative to conventional denim washing.