Abstract
Recently, a new inductive heating method to process fibre reinforced polymer composites was introduced. This method uses particulate susceptors which are affected by an electromagnetic field. The innovative heating method can be used to heat up bulk as well as sheet like materials because the generated thermal energy is distributed intrinsically in the component. Since the heating performance was observed to be closely related to the used susceptor material, other important factors influencing the heating and polymer melting were investigated in an experimental series. The study comprised materials-related parameters, such as filler fraction and particle size, as well as process-related ones, like induction current, coupling distance, and frequency. High density polyethylene (HDPE) doped with different susceptor materials, ferromagnetic as well as electrically conductive, was used for the heating experiments.
The observed influence on the analyzed heating performance of some materials and process parameters could be derived from standard physical laws, in particular the dependence on coil current and the coupling distance. Other process parameters, like the susceptor size and the frequency, were identified to have a more complex relationship on the heating ability. Cast iron particles, which showed the best heating performance in the study, were able to melt the applied HDPE within 90 seconds at a filler fraction of only 5 to 10 wt.%. For future applications of this heating method, a theoretical approach was revealed to deliver a sufficient approximation of the inductive particulate heating in a finite element model.