Effect of Infill Pattern on Flexural Behaviour and Surface Roughness Behaviour of 3D Printed Poly Lactic Acid (PLA) Material

This study aims to examine how the infill pattern affects the flexural behaviour of PLA objects that are 3D printed. Fused Deposition Modelling (FDM) was used to build polylactic acid (PLA) pieces at different infill patterns with a 100% infill density. Fourteen distinct infill patterns have been studied (Grid, Lines, Triangles, Tri-Hexagon, Cubic, Cubic Subdivision, Octet, Quarter Cubic, Concentric, Zig-Zag, Cross, Cross 3D, Gyroid, Lightning). Because of the increased strength of the strut connections in this pattern, the results demonstrated that the Tri-Hexagon infill pattern had the highest mechanical qualities, with 1088.24 MPa. Whereas Grid type infill pattern show minimum flexural strength of 296.79 MPa. There is a increase of 266.6% in flexural strength of Tri-Hexagon against Grid type infill pattern. This was due to the pattern's huge air gaps, which caused the pattern to fracture quickly during testing. Surface roughness of Zig-zag pattern shows the minimum value of Rq = 4.94 µm and Rz = 15.96 µm. It can be concluded that the Tri-Hexagon infill pattern is quite promising when considering the construction time and the amount of filament used whereas Zig-zag pattern can be preferred if surface finish is the concern. The results of this study will assist researchers and manufacturing companies in selecting the right infill pattern, enabling the fabrication of FDM parts with high mechanical qualities and low production costs.