Continuous Welding Behavior of Woven-CF/PPS Laminates Using 2MHz Band High-Frequency Induction Heating

This study aims to reveal the continuous induction welding behavior of CFRTP composites by high-frequency induction heating method. This welding system consists of a high frequency induction heating device (Frequency:1.8 ~ 2.2MHz, maximum output power: 3kW), induction heating coil (double D type coil) and pressing and cooling rollers. This induction heating device has a smaller impedance matching device compared to a self-excited matching device, so it is suitable for continuous induction welding equipment. The material used is woven CF/PPS laminates. The effects of high-frequency power, induction coil height, moving speed of induction coil and pressure of pressing and cooling rollers on continuous induction welding behavior of woven-CF/PPS laminates and single lap tensile shear strength were investigated. The temperature of laminates surface and joining part were measured by K type thin thermocouples. From this experimental result, it was found that the temperature was increased with increasing the high-frequency power, and also the joining part temperature decreased as the induction coil height and moving speed increased. From the result of tensile shear test, it was suggested that the tensile shear strength was influenced by the joining part temperature and the pressure applied by the pressing and cooling roller. Based on the results of this study, it is desired to develop the induction coil that can perform induction heating and pressurization at the same time.