Effect of Process Parameters on Tensile Properties of 3D-Printed Continuous Carbon Fiber-Reinforced PLA Composites

To improve the tensile properties of continuous carbon fiber-reinforced polylactic acid (CCF/PLA) composites fabricated by fused deposition modeling (FDM) 3D printing, this paper optimized process parameters including printing layer height, extrusion width, temperature and speed through single-factor experiments and an L9(34) orthogonal test, and obtained the optimal combination A1B3C1D2. Tensile tests show that the strength and modulus of the specimens under these parameters are greatly improved compared with neat PLA, and are superior to those of optimal groups from single-factor and orthogonal tests. Microscopic morphology reveals uniform fiber dispersion, favorable interfacial bonding and low porosity in the optimized specimens. The fracture is dominated by fiber-matrix synergistic load bearing, leading to better tensile properties and ductility. This work provides data and process support for the application of such composites in lightweight components.