Influence of Structural Parameters of a Wide‐Width Die on the Performance of Short‐Fiber Reinforced Rubber Composites With Radial Orientation

ABSTRACT This study investigates the influence of die design parameters—specifically the flow‐blocking dam gap (2–8 mm), sizing section length (10–25 mm), and sizing section thickness (4–10 mm) of a wide‐width orientation die—on the microstructure and mechanical properties of short basalt fiber‐reinforced rubber composites for conveyor belt covers. A combined approach of finite element simulation (ANSYS) and experimental validation was employed to analyze the flow behavior (pressure, velocity, and shear rate fields) and its correlation with composite performance. The results demonstrate that optimal mechanical properties—including crosslinking density, tensile strength, tear strength, and wear resistance—are achieved with a flow‐blocking dam gap of 2 mm, a sizing section length of 15 mm, and a sizing section thickness of 8 mm. Mechanistically, these optimized die parameters generate a specific shear flow field that minimizes flow stagnation and aligns the short basalt fibers radially along the stress direction. This enhanced radial orientation, confirmed via SEM, significantly improves fiber–matrix adhesion and load transfer efficiency, thereby maximizing composite performance. This work provides practical guidelines for tailoring die geometry to achieve desired fiber alignment and property enhancement in short‐fiber‐reinforced rubber composites.