The effect of different building orientations and different filling patterns on the mechanical properties and building time of PLA using FDM technology

Abstract

Fused Deposition Modeling (FDM) is a Layered Manufacturing (LM) process in which progressive 2D layers of material are kept making a 3D part. To optimize the building operation, investigation is necessary to study the effect of process parameters. This study examines the impact of three filling patterns “Triangles”, “Cross” and “Cross 3D” with three filling densities (25%, 50%, and 75%) in three orientations (“Flat”, “on long edge”, and “on short edge”) on Ultimate Tensile Strength (UTS), hardness and the printing time of Polylactic Acid (PLA) material. In this work, tensile specimens were built according to ASTM D638 on an open-source 3D printer. The UTS were collected using WDW-2000 computer control electronic universal testing machine. Also, the hardiness value was measured using shore A hardness durometers DIN 53505 and ASTEM D2240. In addition, the building time was conducted by implementing “Cura 4.6.” slicer software. The results show that the filling pattern, orientation, and density, at which the part is built, have a significant effect on the strength, hardness, and building time of the part. for light structure parts 25% density, it is recommended to build part with “Triangles” “on long edge” to obtain the highest strength (31.02MPa) which improved by 74.3%, with (281HV) at min. time (1hr:10min) which reduced by 46.1%. For dense structure parts, “Triangles”, “on long edge” are recommended to give the highest strength (42.12MPa), which be improved by 69.8%, (282HV) at min. time (1hr:35min) which reduced by 36.2%. For medium construction 50% the parts can be built by the following parameters “Cross”, “on long edge” to obtain the highest strength (38.48MPa) with (283HV) at min. possible time (1hr:55min).