Investigation of the Effects of the Number of Shells, Raster Angle, Extrusion Ratio, and Path Width on Printed Polylactic Acid Parts with Fused Deposition Modeling 3D Printer

Additive manufacturing technology is a rapidly developing technology in parallel with technological developments. FDM/FFF technology, one of the additive manufacturing technologies, is widely used in many areas. In the study, the effects of the number of shells, raster angle, path width, and extrusion ratio parameters on the mechanical properties, mass changes, and dimensional integrity of the produced parts were investigated. Experiments were performed with seven different numbers of shells (1, 2, 3, 4, 5, 6, 7) and seven different raster angles (0, 45, 90, 0/90, 15/75, 30/60, 45/45). It was made using seven different path widths (0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) and six different extrusion ratios (80, 90, 100, 110, 120, 140%). It was observed that the tensile strength increased (7% change) as the number of walls increased up to a certain number (up to 5), and the lowest tensile strength (41.42 MPa) was obtained in samples with a raster angle of 15/75 degrees. Again, considering the extrusion width, the lowest tensile strength was 38.63 MPa in the samples with a 0.2-mm path width, and the highest tensile strength in terms of path width was 47.28 MPa in the samples with a 0.4-mm path width. Within the scope of the study, it can be said that the extrusion ratio is the most important parameter affecting the tensile strength. When the extrusion ratio is 80%, the tensile strength is 31.32 MPa, and when the extrusion ratio increases to 100%, it is 47.66 MPa. The ratio of change is approximately 34.28%. While the largest deviations in terms of dimensional accuracy occurred at the 140% extrusion ratio, the largest mass deviations occurred at the 80% extrusion ratio. It has been determined that the selected parameters have significant effects on mechanical properties and size and mass changes.