Influence of post-processing CO2 laser cutting and FFF 3D printing parameters on the surface morphology of PLAs: Statistical modelling and RSM optimisation

This study investigates the optimization of 3D printing and CO2 laser cutting parameters by the design of experiments (DOE) and response surface methodology (RSM). In fused filament fabrication (FFF) process, the surface quality of printed curves is poor due to the stairstep defects. The aim is to determine how the laser cutting parameters affect the surface morphology of surface finishing polylactic acid (PLA) samples. A total of 13 cube shape samples are 3D-printed with a cone-shaped hole in the middle. Then, post-processing CO2 laser cutting with a maximum power of 1 kW is used to cut the 3D-printed products. Infill percentage (IP) and extruder temperature (ET) in 3D printing, and laser power (LP), scanning speed (SS), and top edge in CO2 laser cutting are the main parameters in this study. Regression equations are obtained by doing an analysis of the experimental findings using statistical software to examine the impacts of process factors on surface conditions. Results show that the infill percentage and extruder temperature have an extraordinary effect on 3D-printed products' surface quality. 30% infill percentage and 190 °C extruder temperature result in the lowest surface quality with a value of 2.151 μm using DOE and RSM optimization. Also, the lowest value of the top edge is achieved at 275 μm with 300 W laser power and a 5 mm/s cutting speed. The proposed methods can be used to reduce material consumption in the product development.