Investigating the impact of laser polishing parameters on surface roughness, mass ablation rate, and optical transmittance of 3D‐printed PLA substrates

Abstract

AbstractLaser polishing technique is one of the most effective post‐processing methods for 3D‐printed Polylactic acid (PLA) substrates and has gained significant interest of scientific research community in past few years. This paper aims to investigate the effect of fill density, laser power, and scanning speed on the polishing responses of 3D‐printed PLA substrates. These include surface roughness, mass ablation rate, and optical transmittance of PLA substrates printed using the fused deposition modeling technique. The optical transmittance was measured using Fourier‐transform infrared spectroscopy technique and surfaces were characterized using scanning electron microscope, and optical microscope. Minimum surface roughness of 1.04 μm was achieved at 5% laser power and 55% fill density constituting a decrease of 61.8% from unpolished PLA (2.735 μm). The lowest mass ablation rate (0.015 μg/pulse) was observed for the specimens with 40% infill density. Higher scanning speed enhanced the molecular bonding in PLA‐55 specimen indicated by increased peak transmittance ratios of CH bonds at stretching (1.021) and bending modes (1.045).