Abstract
The shell, as the main structure of 3D printed fused filament fabrication (FFF) models, plays a key role in the tensile strength of FFF models. In order to optimise the structural parameters of the shell and improve the tensile strength of FFF models, especially those printed with low-density infill. In this paper, polylactic acid (PLA) filament was selected as the printing material, and the influence of shell structural parameters (shell texture angle, shell layer height, and shell thickness) on the tensile strength of FFF models was investigated by one-way and orthogonal tests. The results of the one-way test show that the tensile strength of the FFF models increases as the shell texture angle decreases, the shell layer height decreases, and the shell thickness increases. Orthogonal test results show that the shell structure parameters affect the tensile strength of the FFF models in the following degree: shell thickness ] shell texture angle ] shell layer height. The optimised shell structure parameters are: shell texture angle of 0°, shell layer height of 0.1 mm, shell thickness of 2.0 mm, and the tensile strength of the FFF models is the largest with this optimised parameter, which is 19.68 MPa.
Keywords: Shell structure; 3D printing; FFF model; Tensile strength