Optimization of 3D Printing Parameters for Enhanced Mechanical Strength: Effects of Glass Fiber Reinforcement and Fill Ratio Using RSM and ANOVA

This research aimed to provide valuable insights for future studies and enhance manufacturing processes by investigating the effect of incorporating fibers into 3D printing to improve the mechanical properties of fabricated components. The experimental design was carried out using Design-Expert software, employing the Central Composite Design (CCD) methodology. Seventeen experiments were conducted, with predefined input parameters, layer height, filler ratio, and printing speed, analyzed through the Response Surface Methodology (RSM) using Design-Expert version 12. An Analysis of Variance (ANOVA) revealed that the filler ratio had the most significant effect on fracture strength. The influence of different printing parameters printing speed, layer height, and filler ratio on the mechanical properties and print quality was systematically investigated. The results indicated that the filler ratio was the most critical factor, with a 100% fill ratio yielding the highest tensile strength. Conversely, a 50% fill ratio significantly reduced production costs, but at the expense of mechanical performance. Thus, if strength is the primary requirement, a higher fill ratio is recommended. The effect of printing speed was found to be less significant compared to layer height and filler ratio. The maximum recorded tensile strength was 540.65 N, achieved with a layer height of 0.5 mm, a 100% fill ratio, and a printing speed of 8 mm/s. In contrast, the lowest recorded tensile strength was 389.93 N, observed with a layer height of 0.4 mm, a 50% fill ratio, and a printing speed of 4 mm/s. After applying a transformation function, the data showed good alignment with the normal distribution on the probability plot, indicating that the assumption of normality was satisfied. Additionally, the incorporation of glass fibers significantly enhanced the mechanical strength of the printed samples.