Modeling microwave-induced heating of 3D-Printed Structures of Polypropylene filled with SiC Whiskers

One of the widely used methods of 3D printing of polymers is fused deposition modeling (FDM) or fused filament fabrication(FFF), which requires a thermoplastic filament to be directed toward a heating block and then deposited layer-by-layer to produce a finished part. Polypropylene(PP) is one of the widely used polymers due to its properties, processability, and low cost. Silicon carbide (SiC) whiskers dispersed within PP matrix absorb microwave radiation and generate heat. To model microwave-induced heating of PP-SiC composites, we solved a heat transfer equation within the cubic sample coupled with the electromagnetic wave equation within the entire microwave oven. We use COMSOL Multiphysics@ software to integrate this system of equations. The composite properties were assumed to be uniform on the length scale of interest. We varied the volume fraction of the SiC whiskers (from 0.3 vol % to 3.0 vol %) and calculated the temperature within the samples during the microwave heating. Our modeling results approximately captured the extent of heating observed in our experiments. Our concurrent experiments also showed (ELS Antonio et al, ACS Appl. Mat & Interf 15, 40042, 2003) that microwave heating of the 3D-printed sample significantly improves its mechanical properties.