Development of Wireless Self-heating Tooling for Polymer Composites Using Microwave Technology

Recently, self-heating tooling, based on embedded pipes or circuits, has attracted extensive attention in processing of polymer composites due to customized temperature fields, high efficiency, and low cost. In this paper, we developed a wireless self-heating tooling with good durability and low thermal mass using microwave technology. Specifically, a hybrid tooling structure including a metallic panel, electromagnetic resonators, and a wave-transparent composite backplane was proposed. For the first time, electromagnetic resonators were employed to realize wireless and rapid microwave heating of the metallic panel. Through optimizing the dimensions of the electromagnetic resonators, a complete microwave absorption in simulation and an absorbance of 81% in reality were obtained, which were robust against polarization and incidence angles. The heating performance of the self-heating tooling was verified, as well as a customized heating process. Experimental results indicated that the composite laminates cured by the self-heating tooling had comparable inner quality and mechanical performance to their thermally cured counterparts, but the energy consumption was reduced by 81.5%. Furthermore, a quick curing process with a heating rate of 10 °C/min was demonstrated, where the curing cycle and energy consumption were reduced by 45.9% and 84.6% compared with the thermal curing process. Our work may provide an easy and practical solution for the manufacture of polymer composites with customized temperature fields, short curing cycle, and low energy consumption.