Fabrication and mechanical characterization of continuous carbon fiber-reinforced thermoplastic using a preform by three-dimensional printing and via hot-press molding

A new 3D printer equipped novel nozzle structure for continuous carbon fiber-reinforced thermoplastics (C-CFRTP) was developed and the suitable printing conditions were studied. C-CFRTP filament and additional matrix resin were supplied independently using each extruder, which is useful for variety printing and precise form control in 3D printing. To measure the mechanical properties, specimens for tensile strength testing were fabricated using C-CFRTP filament (Vf:50%) without additional matrix resin. The experimental results indicate that the tensile strength and Young’s modulus were approximately 700 MPa and 53 GPa, respectively. The recrystallization effect through annealing after 3D printing yielded no drastic improvement. The mechanical properties were considerably improved by a hot-press treatment after 3D printing. The tensile strength and Young’s modulus increased to approximately 1400 MPa and approximately 90 GPa, respectively. These results suggest that one of the useful applications of C-CFRTP 3D printing technology is preforming of small parts in industrial products.