A Facile Molding Method of Continuous Fiber-Reinforced Thermoplastic Composites and Its Mechanical Property

The mechanical properties of continuous fiber-reinforced thermoplastic (C-FRTP) composites are commonly lower than those of continuous fiber-reinforced thermosetting plastic (C-FRP) composites. We have developed a new molding method for C-FRTP. In this study, pre-impregnated materials were successfully prepared by polymer solution impregnation method and, finally, C-FRTP was fabricated. The viscosity of the thermoplastic matrix was decreased to approximately 3dPaxs, the same level of epoxy, and the fiber volume fraction was increased from approximately 45 to 60%. The cross-section of specimens were polished by an ion milling system and impregnation condition was investigated by scanning electron microscopy (SEM). The micrographs suggested that thermoplastic polymer was impregnated to every corner of the fiber, and no void was found on the cross-section. It revealed that void-free composites with perfect mechanical properties can be manufactured with this new molding method. All specimens were submitted to a mechanical measuring equipment, and the mechanical properties of the composite specimens were investigated. Mechanical analysis revealed that tensile property and flexural property of C-FRTP were enhanced up to the same level with C-FRP.

Automated summary

A new molding method for C-FRTP has been developed to fabricate void-free composites with perfect mechanical properties. The study found that using pre-impregnated materials and a thermoplastic matrix with reduced viscosity can increase the fiber volume fraction of C-FRTP and enhance its tensile and flexural properties to the same level as C-FRP.