Layer-wise compaction 3D printing: void reduction and interfacial enhancement for continuous carbon fiber–reinforced thermoplastics

This study incorporated a heating roller into a 3D printer based on fused filament fabrication to develop a layer-wise compaction 3D printer. The heating roller facilitates heat compaction during 3D printing to reduce voids and enhance the interface. Coupon specimens were 3D-printed using a continuous carbon fiber-reinforced nylon composite, and the effects of the process on the microstructure and mechanical properties were analyzed. The porosity was measured using X-ray computed tomography, which demonstrated an effective reduction due to the heat-compaction process. The enhanced mode-I interlaminar fracture toughness was assessed using a double-cantilever beam test. The reduced voids and improved interface led to enhanced bending properties of the composite. The bending fracture surface exhibited a reduced compression failure area as a result of the heat compaction process, indicating an improvement in the compression load-bearing capacity.