Leveraging CO2 laser cutting for enhancing fused deposition modeling (FDM) 3D printed PETG parts through postprocessing

In this study, the experimental investigation of the laser cutting process of polyethylene terephthalate glycol (PETG) sheets fabricated by the fused deposition modeling (FDM), was studied. The PETG sheets, with dimensions of 50 x 100 mm and thicknesses of 2.5, 5, and 7.5 mm, were fabricated using the FDM technique. Then, postprocessing laser cutting of the PETG sheets was undertaken by utilizing a 120-watt CO2 laser cutting. Response surface methodology was used to evaluate the influence of laser power (75-105 W), sheet thickness (2.5-7.5 mm), and cutting speed (4-10 mm/s) on the upper kerf width (UKW), lower kerf width (LKW), the ratio of UKW to LKW (ratio), and upper heat affected zone (HAZ) of the cutting kerf wall. The kerf wall was photographed byusing an optical microscope; and the kerf geometry dimension values were measured by ImageJ software. The results showed that all three parameters of sheet thickness, cutting speed, and laser power have impact on the kerf geometry characteristics. The reduction in the cutting speed and rise in the laser power increased the UKW and LKW, due to the increase in laser input heat. Furthermore, by increasing the sheet thickness and laser power and decreasing the cutting speed, the ratio decreased. Considering the minimum speed of 4 mm/s and maximum power of 105 W in the PETG sheet with a thickness of 7.5 mm, the highest values of the UKW and LKW were 336.6 and 582.2 mu m, respectively. The HAZ decreased as power was reduced and speed was increased. The minimum HAZ value of 118 mu m was achieved at a maximum speed of 10 mm/s with a sheet thickness of 7.5 mm.