Multi‐Parameter Design of Experiments and Process–Performance Mapping for Flexural Optimization in Three‐Dimensional Printed Polyethylene Terephthalate Glycol

This study investigates the influence of key process parameters on the flexural performance of 3D‐printed PETG components fabricated via Fused Deposition Modeling (FDM). A Taguchi L18 orthogonal array design was employed to systematically explore the effects of five variables—printing angle, layer height, layer width, nozzle temperature, and print speed—on flexural modulus, maximum stress, strain at failure, deflection, and toughness. All specimens were produced using a Cartesian‐style FDM printer and tested under three‐point bending according to EN ISO 178:2003. Flexural properties were computed from stress–strain data, and toughness was evaluated through numerical integration. Statistical analysis, including signal‐to‐noise (S/N) ratios, revealed that printing angle and layer height are the most influential factors. Second‐order regression models were developed to predict mechanical performance, showing strong agreement with experimental results ( R 2 up to 0.91). Composite S/N metrics were introduced to simultaneously optimize multiple responses, and contour plots highlighted robust process windows with optimal parameter combinations. The results demonstrate that low printing angles (0°–18°), moderate layer height (0.2 mm), increased layer width (0.4–0.45 mm), and intermediate nozzle temperatures and speeds yield PETG parts with superior and consistent mechanical behavior. These findings provide actionable guidelines for tailoring FDM process settings in structural and biomedical applications. These results complement prior PETG research by providing a multi‐factor, robustness‐oriented framework that has not been previously applied to flexural performance.