Three-dimensional molding of carbon fiber reinforced thermoplastics by direct resistance heating of carbon fibers

Abstract

To mold carbon fiber reinforced thermoplastics (CFRTP), it is necessary to impregnate carbon fiber bundles with thermoplastic resin by heating the materials. A low cost CFRTP molding technique has been developed in which direct resistance heating is applied to the carbon fiber itself. When an electrical current runs through a material, it is heated by joule heat. Therefore this method can be run with simple equipment and low power consumption. In previous studies by the authors, flat plates and pipes of CFRTP were molded using direct resistance heating and the molding capabilities were evaluated. To use this molding method for manufacturing automobile components, it is necessary to apply it to three-dimensional molding. However, the temperature distribution of carbon fiber non-crimp fabric (NCF) has not been investigated when a direct resistance heating method is applied to three-dimensional molding. In this study, the heating properties of carbon fiber NCF formed by layers at 90o and 120o using direct resistance heating were evaluated, and angle plates were molded. Using direct heating to carbon fiber NCF, angle CF/PA6 plates have been successfully molded under the conditions of holding time of 1 minute, pressure of 2 MPa and heating temperature of 290°C.