Mathematical modeling of temperature-dependent resin viscosity and fiber impregnation in GFPP thermoplastic composites

Advancements in high-performance thermoplastic fiber composites such as glass fiber reinforced polypropylene (GFPP) depend on achieving precise and effective fiber wetting and resin penetration. This study presents a temperature-responsive mathematical model that links resin viscosity, viscoelastic flow and thermal conduction in the melt impregnation process. The model helps predict and optimize impregnation quality. Experimentally, GFPP samples were prepared using a twin screw extruder with mold temperatures between 220 to 250 °C, and a constant velocity of 0.7 m/min. SEM and TGA analysis confirmed that GFPP produced at 250 °C showed complete impregnation with a precise void content. Moreover, the mathematical model applied in this study further strengthens the experiment results of how higher temperatures reduce the resin viscosity, thus, enhancing the impregnation and interfacial adhesion bonding within the fiber. These findings provide a strong framework for optimizing process parameters to enhance the thermal stability and mechanical properties of GFPP composites, supporting the production of advanced thermoplastic materials.