Bleaching terry fabric in supercritical carbon dioxide medium: A sustainable solution

Abstract

The textile industry consumes substantial amounts of chemicals, water, and energy, particularly in finishing processes. As sustainability gains increasing importance in the sector, cleaner production approaches are being adopted to develop technologies that minimize the use of these resources. One such innovation is supercritical carbon dioxide (scCO(2)) technology. In this study, the bleaching of terry fabric was performed in a supercritical CO2 medium under specific temperature, time, and pressure conditions. The whiteness index was optimized using the Box-Behnken experimental design. Optimal bleaching conditions were determined to be 83 degrees C, 10% H2O2, 12 MPa, and a processing time of 20 min. Under these conditions, effective bleaching of 100% cotton terry fabric was achieved using only hydrogen peroxide in the scCO(2) medium.Post-bleaching evaluations included tensile strength, pile loop strength, softness assessment, color measurements, and fastness tests. Mechanical tests revealed a reduction in fabric strength following scCO(2) bleaching. Additionally, SEM and FTIR analyses were conducted on the treated samples to investigate morphological and chemical changes. Subsequent dyeing trials demonstrated comparable colorimetric and fastness properties to conventionally treated fabrics.