Fine Punching of Carbon-Fiber-Reinforced Thermoplastic Sheets

Abstract

Press forming for the mass production of carbon-fiber-reinforced thermoplastic (CFRTP) sheets has recently been studied intensively in order to reduce the weight of transport machinery and to improve collision safety. The authors examined the possibility and practicality of the fine punching of CFRTP sheets using a press machine employed for press forming. The following results were obtained. (1) In the shave punching of CFRTP sheets, materials were separated by cutting them regardless of the relatively large shaving allowance, resulting in a smooth cut surface. Moreover, shave punching was also successfully applied to very thick sheets, with the increase in shaving load being extremely small even when the sheet thickness was increased. (2) In vibro-punching, a conventional punching die was attached to a numerical control (NC) servo press, and a vibrating punch was induced to cut into the materials during the process. With this vibration motion, fine punching became easier to perform than conventional vibro-punching．