Optimizing Injection Molding Parameters for Enhanced Properties in Glass Fiber-Reinforced Polypropylene

Abstract

The mechanical properties of fiber-reinforced polymer matrix composites are largely influenced by the characteristics of their constituents, including the matrix and fibers. During injection molding, various process parameters such as thermal and pressure variations play a critical role in shaping the final properties of the molded parts. This study investigates the impact of key process parameters controlling the solidification of glass fiber-reinforced polypropylene (PPGF) plates, including injection temperature and packing pressure, on warpage, hardness, tensile strength, and flexural properties. To the best of the authors’ knowledge, studies on the characterization of changes induced in flexural properties by modifications to injection molding process parameters in fiber-reinforced polymers are limited. Through a statistical analysis, the relationship between process parameters and the contribution of fibers to the composite’s mechanical performance is assessed by comparing the properties of reinforced and unreinforced materials. While the addition of fibers tends to increase warpage, optimal combinations of process parameters significantly reduce warpage while enhancing mechanical properties such as tensile and flexural moduli. These findings offer valuable insights into optimizing injection molding conditions to minimize warpage and improve mechanical properties.