Effect of Infill Density and Infill Pattern on Mechanical Properties of 3D-printed PLA Produced by FFF

With the rapid advancements in Additive Manufacturing (AM) technology, examining the mechanical properties of products utilized in this process has become increasingly important. The mechanical properties of 3D-printed products are significantly influenced by the choice of printing methods and printing parameters. Despite ongoing progress, research exploring these effects remains limited. Therefore, the aim of this study is to examine the effects of these production parameters on samples produced with PLA material with different infill densities and infill patterns using the fused filament fabrication technique, one of the AM methods. For this purpose, test samples with five patterns (cubic, tri-hexagon, octet, grid, and zigzag) and two densities (50%, 60%) were produced. In addition, 100% infill density was created with a solid infill pattern and selected as a reference. Mechanical tensile and Charpy tests were conducted on all samples. The results indicate that infill parameters have significant effects on the energy absorption and tensile strength of 3D-printed products. Printing patterns influence the tensile strength of printed structures, with octet-patterned structures showing the maximum tensile strength at 42 MPa and the highest energy absorption value at 16.94 kJ.mm-2. Furthermore, it was found that the tensile strength increases with increasing infill density. The values obtained from the mechanical tests in this study will serve as a reference for selecting the correct infill parameters in the slicing program for 3D-printed products requiring high-strength.