Combined Scouring and Bleaching of Cotton/Linen Blends by a Near-Neutral Activated Peroxide System

Abstract

The simultaneous scouring and bleaching of cotton/linen blends was performed in a near-neutral activated peroxide system (pH = 7.2). A response surface quadratic model (RSQM) based on the central composite design (CCD) was established to investigate and optimise the bleaching performance. Research results showed that hydrophobic impurities in the blends had little impact on the bleaching. Temperature was the most significant factor affecting the fabric’s whiteness index (WI), followed by the concentration and duration of the activator tetraacetylethylenediamine (TAED). The optimised process was performed at 70 °C for 40 min, incorporating 20 mmol/l of TAED and 42 mmol/l of H2O2. Compared with the conventional process carried out at 95 °C for 60 min and adding 80 mmol/l H2O2, the activation process provided the fabric with comparable WI and wettability, a smoother and cleaner microcosmic surface, as well as the advantages of saving energy and preserving fabric. This study confirmed the feasibility of an efficient one-step process for neutral scouring and bleaching.