Mechanical performance of FDM-printed PLA: a comparative study of single, double and triple infill pattern configurations

Purpose This paper aims to analyse the mechanical behavior specifically tensile, compressive and flexural properties of 3D-printed PLA components generated using various infill patterns by the Fused Deposition Modeling (FDM) process. By evaluating single, double and triple-pattern infill configurations, the study tries to understand how geometric complexity in infill structures effects mechanical performance. Design/methodology/approach A conventional FDM printer was used to create 12 different infill configurations with an 80% infill density and a 0.15-mm layer thickness. These configurations included four double combinations, four triple combinations and four single patterns (triangles, grid, lines and trihexagon). The samples were submitted to standardized tensile, compressive and flexural tests to measure their mechanical responses. Findings The Lines + Triangles + TriHexagon infill pattern exhibited the highest tensile strength of 99.24 MPa, while the Triangles + Tri-hexagon pattern achieved the highest compressive strength (58.3 MPa). In flexural testing, theline + Triangles pattern yielded the highest flexural strength (97.59 MPa), closely followed by the Triangles + TriHexagon + Cubic (96.88) patterns. Increased infill complexity correlated with improved mechanical strength in some cases but also resulted in extended printing times. Practical implications The findings highlight the importance of selecting appropriate infill patterns to enhance the structural integrity of FDM-printed parts without compromising printing efficiency. Designers and engineers can leverage this knowledge to optimize part performance in functional and load-bearing applications, particularly in prototyping and end-use scenarios. The very small number of specimens examined for each formulation is one of the study’s limitations, which might compromise the published findings’ statistical validity. Originality/value This study provides a comprehensive comparison of multiple infill pattern combinations in FDM-printed PLA components, offering novel insights into the influence of pattern complexity on mechanical performance. The systematic evaluation of single, double and triple infill structures contributes to the advancement of infill strategy optimization in additive manufacturing.