Optimizing Ozone Gas Bleaching for Interlock Knitted Fabric:A Comprehensive Study on pH, Flow Rates, and Ozonation Durations

Abstract

In this study, the bleaching of interlock knitted fabric using an innovative and environmentally friendly method involving ozone gas was explored. The bleaching processes were conducted under varying conditions: different pH levels (pH 7 to pH 12), ozone gas flow rates (2 L/min to 6 L/min), and ozonation durations (20, 40, and 60 minutes). Fabrics treated with ozonation were compared to those subjected to conventional bleaching methods. Assessments of the samples were performed for whiteness, bursting strength, color measurements, and fastness properties. Additionally, Chemical Oxygen Demand (COD) tests were conducted on wastewater from both conventional bleaching and ozonation processes. Optimal conditions were determined to be at pH 7, with a 6 L/min ozone flow rate, and a 60-minute duration. Under these conditions, the whiteness index reached 80 Stensby, and the yellowness index was 7.6. Furthermore, a reduction of approximately 90 % in COD values was observed, indicating a significant decrease in environmental impact. However, a decrease of about 30 % in burst strength was also noted. This study highlights the potential of ozone technology to replace traditional chemical-intensive methods, offering a more sustainable solution for the textile industry.