Finishing of denim fabrics with ozone in water

Abstract

The wet processing of denim jeans is required to achieve comfortable touch and versatile appearance for the final product. The finishing of denim jeans with ozone offers ecological and economic advantages by decreasing rinsing times, water and energy consumption. Ozone, a selective oxidant with high reduction potential, has proven to decolorize textile effluents and it is especially capable of reacting with indigo. In this study, the effect of ozone on the color change of denim fabrics and on the backstaining of the pocket fabrics was studied. Seven different denim fabrics, dyed with the indigo and mixture of indigo and sulfur dyes, were desized and bio-stoned and thereafter treated with ozone in aqueous medium. The response of the color of the indigo dyed denim fabrics to ozone was stronger in comparison with the fabrics dyed with the mixture of indigo and sulfur dyes. The pocket fabrics backstained during the desizing and bio-stoning and subsequent ozone treatment was able to decrease the backstaining. Ozone was able to bleach the denim jeans and decreased the backstaining without the significant loss of the strength of the fabrics. The combined desizing and enzyme wash followed by the ozone wash is thus a promising finishing treatment for denim jeans.