Microwave-assisted 3D printing of epoxy resin ink using rectangular waveguide

ABSTRACTDirect ink writing of thermosetting materials, e.g. epoxy resin, is a promising technique for the rapid and low-cost fabrication of high-strength parts with complex geometry. In this study, a microwave-assisted 3D printer using rectangular waveguide (RWG) was developed to overcome the ink's low viscosity and slow curing speed. Microwave curing and ink extrusion are synchronous to improve shape retention of ink. The critical structure parameters of the RWG applicator were determined using the multiphysics simulation to achieve optimal microwave system matching and ink heating uniformity. Experiments were conducted to investigate the processing parameters and printability. At microwave radiation temperature 95°C, the extruded ink has a significantly increased storage modulus and presents a stable and continuous cylindrical gelatinous state. Filaments can be deposited with high-quality at screw rotary speed 70 rpm and printing speed 5 mm/s. The printed sample demonstrates the excellent printability of multiple layers of extruded ink.