Fabrication of a continuous carbon fiber-reinforced phenolic resin composites via in situ-curing 3D printing technology

An in situ-curing 3D printing technology was developed, which comprised resin impregnation, 3D printing/pre-curing and post-curing processes. Continuous carbon fiber-reinforced thermosetting phenolic resin (CF/PF) composites were fabricated based on that. The selection of pre-curing temperature was the key to successful printing. The deviation distances of prepregs during 3D printing, degrees of curing and defect volumes of the composites after 3D printing and post-curing were used to determine the pre-curing temperature. With the optimum pre-curing temperature of 260 °C, the deviation distance of the prepreg was 8.57 mm, defect volume of post-cured CF/PF composite was 12.1% and its mechanical properties were optimal. The degree of curing was 80.7% after 3D printing, which could maintain the structure integrity during the 3D printing and post-curing processes.