Enzymatic scouring and low-temperature bleaching of fabrics constructed from cotton, regenerated bamboo, poly(lactic acid), and soy protein fibers

Abstract

In the present study, fabrics constructed from cotton, regenerated bamboo, poly(lactic acid), and soy protein fibers were scoured with pectinase enzymes, bleached with different bleaching processes using peracetic acid (PAA), and conventionally bleached with hydrogen peroxide (HP). The enzymatic scouring and bleaching with PAA have been chosen in order to minimize fiber damage and to perform the processes in more benign conditions. PAA was added to the bleaching bath in the form of a commercial solution or it was produced in situ in the presence of HP with the addition of a bleach activator, tetraacetylethylenediamine (TAED), or arylesterase enzymes. The conventional process was performed at 90 °C in highly alkaline pH media, and the bleaching processes with PAA were performed at 65 °C in neutral to slightly alkaline pH media. The results revealed that after the enzymatic scouring, the hydrophilicity of the fabrics is adequate. Compared with the cotton fibers, the regenerated bamboo and especially the poly(lactic) acid and soy protein fibers are significantly damaged during conventional HP bleaching. By contrast, bleaching with PAA revealed a strong whitening ability that is comparable to that of conventional bleaching with HP but with substantially reduced fiber damage.