Investigation on process parameters of 3D printed continuous carbon fiber-reinforced thermosetting epoxy composites

Continuous fiber-reinforced thermosetting polymer composites (CFRTPCs) were prepared via three-dimensional (3D) printing in this study. The entire process was divided into impregnation, printing, and curing stages. The impregnation stage ensured a tightly bonded interface and uniform distribution of fibers and resin. The printing stage solved the great conveying resistance and poor adhesion caused by the addition of continuous fibers. The curing stage aimed to preserve the shapes of the pre-formed samples and completed the polymerization and crosslinking reactions. An investigation into the experimental design focused on optimizing the parameters of the manufacturing process, wherein printing speed, printing space, printing thickness, curing pressure, and curing temperature were selected as target variables. Finally, 3D printed CFRTPC samples with 58 wt.% fiber content exhibited maximum flexural strength and modulus of 952.89 MPa and 74.05 GPa, respectively. Moreover, complex CFRTPC components were fabricated to demonstrate the feasibility and generality of the proposed technique. These results may broaden the potential use of 3D printed CFRTPCs in aerospace, defense, and automotive applications.