Optimization of Injection-Molding Process for Mechanical and Tribological Properties of Short Glass Fiber and Polytetrafluoroethylene Reinforced Polycarbonate Composites with Grey Relational Analysis: A Case Study

This study analyzes the mechanical properties and tribological behaviors of polycarbonate (PC) reinforced with 20% short glass fiber (SGF) and 6% polytetrafluoroethylene (PTFE), which is applied to the bottom cover of the card reader body. The specimens were prepared under different injection-molding conditions, by varying the filling time, the melt temperature, the mold temperature and the packing pressure. Grey relational analysis is then applied to obtain an optimal parameter setting. Plans of experiments via nine experimental runs are based on the orthogonal arrays to determine the optimum factor level condition. The mechanical properties of ultimate stress, and the tribological behaviors of surface roughness and friction coefficient variation are adopted as the quality targets. The tensile test were performed with a 25 kN computerized MTS. Simultaneously, friction and wear tests were performed with a Schwingum Reibung Verschleiss (SRV oscillation friction wear) ball-on-plane tester. Additionally, the worn surfaces were examined with scanning electron microscopy (SEM). Melt temperature was found to be the most influenced factor inultimate stress, surface roughness, and friction coefficient for the injection molding process in this study.