Performance of Low-Temperature Bleaching Techniques for Cotton Fabrics Using Hydrogen Peroxide Activators.

Cotton fibers contain impurities that must be removed before dyeing/printing. Traditional hydrogen peroxide bleaching is energy- and time-intensive, requiring near-boiling temperatures and over 60 min. This study evaluates triacetin, peracetic acid, and performic acid as hydrogen peroxide activators to lower the temperature and process time in cotton bleaching. The best results were achieved with 0.9 g·L triacetin and 1.0 g·L peracetic acid at 80 °C for 30 min, reaching 61.1 Berger whiteness. Subsequent tests revealed a slight color difference in dyeings with triacetin (0.5 Δ CMC2:1) and high dye affinity (103% tinctorial strength) compared to conventionally bleached samples. Lighter colors showed a greater bleaching influence. This result is 97% similar to that of conventional bleaching, suggesting a promising alternative for sustainable textile production. This approach stands out for its ability to reduce processing temperatures and times, resulting in lower energy consumption and greater efficiency while maintaining nearly the same fabric whiteness and dyeing quality as conventional methods. It also provides insights into color sensitivity during bleaching.