Impact of Printing Parameters and Post-Curing on Surface Quality in mSLA 3D Printing

This study experimentally investigates the effects of printing parameters and post-curing on the surface roughness of photopolymer-based parts produced using the masked stereolithography (mSLA) method. Parameters such as layer thickness (0.02–0.04 mm), exposure time (3–5 s), and printing angle (0–45°) were determined using an L9 Taguchi orthogonal design, and both as-printed and post-cured samples were produced for each combination. Surface roughness was measured in areal (Sa) format using an optical profilometer, and the data were evaluated using analysis of variance (ANOVA) and SN ratios. The findings showed that surface roughness was mostly affected by layer thickness, followed by printing angle, while exposure time had a limited effect. The lowest Sa value was obtained with a layer thickness of 0.02 mm, an exposure time of 3 s, and a printing angle of 0°. Post-curing reduced surface roughness by 8–11% in all groups. However, the magnitude of this improvement depends on the initial surface irregularity. Consequently, it has been demonstrated that both printing and curing parameters should be optimized in applications requiring high surface quality.