Evaluation of mechanical properties of press and injection hybrid molded products using CNT grafted plain woven carbon fiber fabric at rib roots

In the press and injection hybrid molding of CFRTP, thermoplastics are injected on the preheated continuous fiber-reinforced thermoplastics. Since the press and injection hybrid molded products fracture at the interface between the continuous fiber-reinforced thermoplastics and the injection material, improving methods of the interfacial properties are required. In the press and injection hybrid molding, when the continuous fiber-reinforced thermoplastics are preheated, the resin disappears by thermal decomposition and the carbon fibers are frequently exposed on the surface of the continuous fiber-reinforced thermoplastics. We reported that the interfacial strength between the fiber and the matrix is increased by grafting CNT on the carbon fiber. Therefore, by supplying the CNT grafted plain woven carbon fiber fabric into the interface between the continuous fiber-reinforced thermoplastics and the injection material, the improvement of the interfacial properties can be expected. In this study, to clarify the effects of the CNT grafted plain woven carbon fiber fabric on the mechanical properties of the press and injection hybrid molded products, resin impregnation of CFRTP laminates was evaluated and, the tensile test and the tensile shear test at rib roots were conducted. Grafting CNT on the plain woven carbon fiber fabric improves the resin impregnation due to the better wettability of CNT grafted plain woven carbon fiber fabric. Supplying the CNT grafted plain woven carbon fiber fabric into the interface between the continuous fiber-reinforced thermoplastics and the injection material results in the improvement of the tensile strength and the tensile shear strength at rib roots. © 2019 The Society of Materials Science, Japan.