Enzymatic One-bath Desizing — Bleaching — Dyeing Process for Cotton Fabrics

Abstract

The objective of this study was to develop a new process to desize, bleach, and dye starch-sized cotton fabrics in one bath using enzymes. Desizing was performed with an amyloglucosidase/pullanase enzyme (Dextrozyme DX, manufactured by Novozymes) instead of a conventional amylase enzyme in order to hydrolyze starch into single glucose units. Multifect GO 5000L (Genencor) glucose oxidase enzyme was used to yield hydrogen peroxide from the glucose generated during desizing; bleaching was performed by this enzymatically generated hydrogen peroxide. Decomposition of hydrogen peroxide after bleaching was done with Terminox Ultra 10L (Novozymes) catalase enzyme. The fabric was dyed in the same bath with the selected monochlortriazine reactive dyes (DyStar). The amount of glucose generated during desizing was 4000 ± 135 mg/l and it yielded 765 ± 15 mg/l hydrogen peroxide during glucose oxidase enzyme treatment. The whiteness index of the enzymatically bleached fabric was 71.0 ± 1.2 stensby degree. The color yields of the enzymatically treated samples were comparable to the conventionally treated samples. All enzymes used in this study were commercial grades having the advantages of easy storage and supply compared to the pure enzymes used in earlier studies. The advantages of the new one-bath process were: less auxiliary demand; lower environmental impact; and energy and water savings compared to the conventional desizing, scouring, bleaching, and dyeing sequence.

Laccase-mediated system pretreatment to enhance the effect of hydrogen peroxide bleaching of cotton fabric

“…Materials treated this way have enhanced wettability, retained tensile strength and acceptable white index values. Though the effect of the "green" short-flow process is not as good as that of conventional chemical process, the former is also sufficient for the fabric to be dyed [27]. Meanwhile, the "green" short-flow process presents an economically attractive alternative for the textile industry due to its relatively low consumption of energy and water.…”

Sustainable textile dyeing processes

“…The excess peroxide present after bleaching can be decomposed by catalase enzyme. Catalase enzymes split H 2 O 2 into oxygen and water to avoid interference of H 2 O 2 during dyeing (Eren et al 2009). …”

Combined one-bath desizing–scouring–depilling enzymatic process and effect of some process parameters

“…The water absorbency and whiteness index values were increased without any fabric damage with this combined process. Eren et al (2009) conducted a study about combined enzymatic desizing ? bleaching and dyeing in the same bath in two steps.…”