Influence of infill pattern on tensile strength and material efficiency of fused deposition modelling (FDM)-printed polylactic acid (PLA) parts

This study investigates the influence of infill patterns and densities on the tensile properties of Fused Deposition Modeling (FDM) 3D-printed Polylactic Acid (PLA) parts, aiming to optimize material efficiency while maintaining structural integrity. Eight infill patterns—Cross 3D, Subdivision Cubic, Octets, Quarter Cubic, Concentric, Grid, Gyroid, and Zigzag—were tested at 45%, 55%, and 65% infill densities, with a solid specimen (100% infill) serving as a benchmark. Tensile testing revealed that the Quarter Cubic pattern at 65% infill density closely matched the mechanical strength and stiffness of the solid specimen while significantly reducing material usage. Statistical analysis using the Taguchi method and ANOVA identified infill percentage as the most influential factor (p = 0.003), while regression modeling (R2 = 91.88%) demonstrated robust predictive capability. This study contributes novel insights into the interplay between infill design and mechanical performance, guiding sustainable production of high-strength, lightweight PLA components for applications in aerospace, automotive, and consumer products.