Hybrid Taguchi–Composite Scoring Approach Framework for Multi-Objective Optimization of Ring Spinning Process: Yarn Tension, Cop Diameter and Yarn Breakage Rate

In this study, we investigate the optimization of ring spinning parameters affecting key yarn quality characteristics, including yarn tension, cop diameter, and end breakage. Experiments were conducted on cotton–polyester yarn using three process variables: traveler mass (60, 67.5, and 75 mg), spindle speed (12,900, 13,300, and 13,700 min⁻¹), and doff stage (43, 111, and 179 mm). A two-stage optimization method was applied: we used the Taguchi method to optimize individual responses, while a normalization-based composite scoring approach was used to integrate them to determine globally optimal ring spinning parameters under differing response-specific conditions. The results show that traveler mass is the dominant factor influencing yarn tension, contributing 65.48% and 73.29% of variation at the bottom and top ring rail positions, respectively. Cop diameter is primarily governed by doff stage, contributing 89.43% of total variance (ANOVA), with the intermediate level (111 mm) yielding the highest mean diameter and the most favorable S/N ratio. The yarn breakage rate is mainly affected by doff stage (57.26%) and spindle speed (41.89%), with minimum breakage observed at moderate spindle speed and mid-level doff stage. The global optimal parameter combination (60 mg traveler mass, 12,900 min⁻¹ spindle speed, and 111 mm doff stage) achieved balanced multi-response performance. The framework demonstrates strong predictive capability (R² > 0.991) and enables optimization.