Investigation and Optimization of a New Bleaching Process for Sulfur-Dyed Denim Fabric

Bleach method is among the most popular washing techniques in the textile industry, especially for washing jeans, to achieve the desired color shade. This process is mostly carried out using hypochlorite and other bleaching agents, which are strongly associated with harmful effects on the environment and human health. Therefore, more environmentally sustainable processes should be created and developed. In this paper, we present an experimental study on the effect of a new bleaching process on the color of a sulfur-dyed black denim fabric. The new process is eco-friendly, because it does not use chlorine. Color degradation (D) was studied to evaluate the color changes. In the first part, a preliminary study was carried out to visualize the field of study of the bleaching treatment parameters (concentration of hydrogen peroxide, temperature, and duration). In the second part, the influence of the chosen parameters on the color degradation was studied using the MINITAB software. Then, a mathematical model was implemented to study the effect of different bleach treatment parameters on color changes, which is required by industrialists in the textile sector. Finally, the best combination of bleaching parameters to obtain an optimal value of color degradation (D) was determined.