Investigation of the Effect of Infill Pattern of 3D Printed PLA Components on Tensile and Flexural Properties through Experimentation and SEM

The study investigates the mechanical properties of the fifteen components having different infill patterns produced using Polylactic Acid (PLA) and Fused Filament Fabrication (FFF) technique. According to ASTM standards, the tensile and flexural testing were conducted, which showed that the honeycomb design has the best overall mechanical performance. Infill density, printing speed, layer height, and nozzle temperature are the factors considered for optimization through Response Surface Methodology. The optimal parameters resulting in increased tensile and flexural properties are infill density of 30%, print speed of 75.43 mm/s, layer height of 0.1029 mm, and nozzle temperature of 218.74 °C. The statistical models used are highly significant (R²>0.95). Further, Scanning Electron Microscopy (SEM) is used to provide insight into the fracture mechanism, which validated the behaviour of the materials observed during testing. This combined experimental/analytical methodology provides a valuable approach to identify the best combination of infill patterns to achieve the desired mechanical properties in PLA parts fabricated using the FFF technique.