Insights into Induction Heating Processes for Polymeric Materials: An Overview of the Mechanisms and Current Applications

In polymer systems, induction heating (IH) is the physical outcome that results from the exposure of selected polymer composites embedding electrically-conductive and/or ferromagnetic fillers to an alternating electromagnetic field (frequency range: from kHz to MHz). The interaction of the applied electromagnetic field with the material accounts for the creation of magnetic polarization effects (i.e., magnetic hysteresis losses) and/or eddy currents (i.e., Joule losses, upon the formation of closed electrical loops), which, in turn, cause the heating up of the material itself. The heat involved can be exploited for different uses, ranging from the curing of thermosetting systems, the welding of thermoplastics, and the processing of temperature-sensitive materials (through selective IH) up to the activation of special effects in polymer systems (such as self-healing and shape-memory effects). This review aims at summarizing the current state-of-the-art of IH processes for polymers, providing readers with the current limitations and challenges, and further discussing some possible developments for the following years.