Optimization of Thermoplastic Pultrusion Processing Parameters for Glass Fiber/Polyphenylene Sulfide Hybrid Commingled Yarn Composites Using Response Surface Methodology

ABSTRACT This study presents the optimization of the pultrusion process for high‐performance thermoplastic composites fabricated from glass fiber/polyphenylene sulfide (PPS) hybrid commingled yarns. The effects of key process parameters—die temperature (280°C–340°C), pulling speed (0.2–1 m/min), and number of fiber strands (4–6)—on interlaminar shear strength (ILSS) were systematically investigated. Characterization of the commingled fibers indicated tensile strengths of 1,691 MPa for glass fiber and 508 MPa for PPS, with a glass fiber weight fraction of 36.91%. A Box–Behnken design and response surface methodology (RSM) were employed to develop a quadratic regression model, which predicted ILSS with a high degree of accuracy (R ² = 0.9897). Analysis of variance (ANOVA) confirmed that all parameters significantly influenced ILSS, with die temperature being the most critical factor. The optimal pultrusion conditions were identified as a die temperature of 310°C, pulling speed of 0.2 m/min, and six fiber strands, achieving a maximum ILSS of 50.5 MPa. The validated model provides a reliable tool for predicting ILSS and defines an optimized processing window, facilitating the industrial‐scale production of thermoplastic composite profiles with superior mechanical performance. The physical and mechanical properties of the produced composite in the optimal state were also evaluated.