A comparison of compression molded and additively manufactured short carbon fiber reinforced polyamide‐6 samples and the effect of different infill printing patterns

Abstract Tensile samples were 3D printed using a commercially available 3D printing material, and the same material was pelletized and hot‐pressed. The samples had a 0°, ±45°, and a 90° filling orientation and their tensile modulus and tensile strength of the samples were determined and compared between fabrication methods. A tensile modulus of 7.56 ± 0.35 GPa (0°), 5.10 ± 0.13 GPa (±45°), and 4.05 ± 0.13 GPa (90°) was found, and the same trend was found for the tensile strength, 92.0 ± 9.5 MPa (0°), 63.3 ± 8.3 MPa (±45°), and 58.7 ± 2.2 MPa (90°). The hot‐pressed samples possessed a tensile modulus of 8.13 ± 0.8 GPa and tensile strength of 98.3 ± 6.8 MPa, very similar to that of the 0° printed samples. These results could be attributed to the printing mechanism and poor adhesion between each deposited composite layer was observed, contributing to the depressed properties. Thermogravimetric analysis was conducted and the carbon fiber content per weight of the commercially sourced printing material was determined to be 13.9%, and the length of the filaments showed that more than 50% of all measured fragments were between 50 and 150 μm.