Optimizing 3D printing parameters for PLA and PETG: advancing high-quality skull implant production

This study investigates the mechanical performance of 3D-printed polylactic acid and polyethylene terephthalate glycol materials by examining the effects of three crucial printing parameters (layer thickness, infill density, and infill pattern). Each material was tested mechanically for impact toughness, flexural strength, ductility, and ultimate tensile strength (UTS) using a Box-Behnken Design (BBD) to create 15 samples. The statistical significance of each parameter's impact was evaluated using ANOVA. The findings showed that, for PLA, layer thickness had no discernible impact on impact toughness (p = 0.726), while infill density (p = 0.031) and infill pattern (p = 0.049) had the most significant effects. In PETG, layer thickness (p = 0.038) and infill pattern (p = 0.021) significantly impacted impact toughness. None of the parameters had a statistically significant impact on the flexural strength of either material.PETG was highly responsive to the same factor (p = 0.022), and PLA was highly sensitive to the infill pattern (p = 0.003) regarding ductility. Both materials' UTS were significantly impacted by infill density, and PETG showed a high sensitivity to the infill pattern (p = 0.004). The ideal parameters for polyethylene terephthalate glycol (PETG) were a tri-hexagonal pattern, a 0.3 mm layer thickness, and an 80% infill density; for polylactic acid (PLA), they were a 0.15 mm layer thickness, an 80% infill density, and a grid infill pattern. These optimized settings were successfully used to create a PETG-based skull implant and functional test prints, demonstrating the applicability of the optimization strategy in practical situations.