Influence of Infill Ratio, Pattern and Orientation on Impact Resistance of 3d-Printed Pla, Petg, Pc

This study investigates the impact resistance of Fused Deposition Modelling (FDM) 3D-printed thermoplastics (Polylactic Acid, Polyethylene Terephthalate Glycol, and Polycarbonate) fabricated for comparative performance assessment under varying infill ratios (40%, 60%, and 90%), infill patterns (grid and gyroid), and print orientations. Impact strength was evaluated using a mini Charpy test to assess fracture energy trends specific to each material across all tested configurations. Results show that increasing the infill ratio improved impact resistance with the grid pattern generally outperforming the gyroid, although the gyroid pattern showed benefits for PLA at high infill densities. PLA was most sensitive to infill changes, PETG showed moderate improvements, while PC showed the most consistent improvement. Print orientation had a notable effect; flatwise specimens achieved the highest energy absorption, while edgewise and upright orientations showed reduced toughness. These findings confirm the critical role of infill and orientation in optimizing the mechanical performance of FDM parts.