Employing response surface methodology in the production of sustainable PC yarn from recycled polyester and recycled cotton

The textile sector has been rapidly shifting toward recycled fibers, propelled by the growing ecological concerns, compliance requirements of the circular textiles strategy, volatile virgin-fiber prices, and a growing demand from eco-aware consumers for sustainable clothing. In light of these trends, this study aims to create eco-friendly and sustainable polyester-cotton (PC) yarns by optimizing the use of recycled fibers. Specifically, the research replaces virgin polyester entirely with recycled polyester and incorporates recycled cotton to reduce reliance on virgin cotton. An I-optimal mixture design, a component of Response Surface Methodology (RSM), was applied to determine the ideal blend ratio of recycled polyester, recycled cotton, and virgin cotton while satisfying the desired yarn strength and elongation required for fabric production. The design expert software recommended sixteen experimental runs with distinct blend ratios. The responses (quality parameters) of the sample yarns were evaluated, and regression analysis along with ANOVA was conducted to develop predictive models and response surface equations for each response. The analysis identified an optimal fiber blend consisting of 70 % recycled polyester, 18 % recycled cotton, and 12 % virgin cotton. Yarns produced using this optimized composition exhibited properties closely aligning with the predicted values, thereby validating the effectiveness of the I-optimal mixture design in optimizing fiber blends and reliably forecasting yarn characteristics.