Study on the Effect of the Molding Process and Service Temperature on the Mechanical Properties and Low-Velocity Impact Performance of the Ultra-High Molecular Weight Polyethylene Fiber Laminates

The ultra-high molecular weight polyethylene (UHMWPE) fiber laminates were prepared by hot pressing at temperatures ranging from 120 to 140 °C and pressures of 15 and 25 MPa. Mechanical test results demonstrated that increasing the molding temperature improved the interlaminar shear strength, in-plane shear strength, and bending strength of the laminates. Additionally, the in-plane tensile properties of the laminate were influenced by both the positive effect of increased bond strength and the negative effect of reduced fiber strength. The mechanical properties of the laminate showed improvements at −50 °C but decreased at 70 °C. Low-velocity impact tests revealed that higher molding temperature and pressure enhanced the dynamic bending stiffness and peak force while reducing the bulge in the laminate's back. Remarkably different low-velocity impact performance was observed in the laminate at −50 and 70 °C compared to room temperature.