Improvement of surface finish in support-affected FDM-fabricated PC-ABS components using laser finishing technique

Fused deposition modeling (FDM) is widely used for fabricating polymeric components; however, surfaces formed in contact with support structures often exhibit poor surface quality due to irregular layer deposition and support-induced surface texture. This study investigates the effectiveness of CO 2 laser finishing for improving the surface roughness of support-affected PC-ABS components. PC-ABS specimens were fabricated using a Fortus 400mc FDM system and finished using a 30 W CO 2 laser. A Taguchi L9 orthogonal array was employed to investigate four laser parameters: resolution, engraving passes, grayscale (PDI), and engraving power, with three replications for each experimental condition. Surface roughness was measured using a profilometer, while cross-sectional microscopy was used to examine material removal. Signal-to-noise analysis and ANOVA were used to determine the optimal process conditions and parameter contributions. The optimum combination was 600 DPI, 2 engraving passes, 90 PDI, and 90 % power. The predicted surface roughness was 3.522 µm, while the confirmation experiment yielded 3.564 µm, resulting in a prediction error of only 1.178 %. The S/N ratio prediction error was 0.915 %. ANOVA revealed that resolution was the dominant parameter, contributing 69.63 % to surface-roughness variation, followed by engraving power at 8.60 %. The findings demonstrate that controlled CO 2 laser finishing provides an effective non-contact approach for improving support-affected FDM surfaces and provides a quantitative basis for optimizing laser-finishing parameters.