Modeling the Fading Kinetics of Textile Dyes during Washing

The textile industry faces increasing pressure to minimize its environmental footprint, particularly in terms of water use and chemical discharge during laundering processes. This study investigates dye fading in cotton fabrics under conventional washing conditions to support the development of more sustainable textile maintenance practices. Eleven anionic and four nonionic dyes, representative of the most used in industrial applications, were analyzed. A response surface methodology (RSM) was employed to identify the washing parameters that most significantly influence color stability, including the temperature, pH, mechanical action, time, and detergent composition. A rate-based kinetic model was validated to describe the dye-fading process, providing a predictive tool to optimize washing conditions and reduce unnecessary chemical and energy consumption. The results show that temperature and bleaching agents, particularly hypochlorite, play an important role in accelerating dye degradation, with pronounced effects observed for direct yellow, disperse navy, and acid red dyes. For reactive dyes, the interaction between temperature and hypochlorite proved especially significant, highlighting the complex coupling of reaction kinetics and oxidative chemistry during washing. By quantitatively linking operational parameters to dye stability, this study provides a rate-based approach for optimizing washing processes and improving the chemical performance of textile and detergent formulations.