Experimental and statistical evaluation of laser beam machining of additively manufactured polylactic acid/wood composites

Additive manufacturing (AM) via fused filament fabrication (FFF) has gained widespread adoption for fabricating polymer components. However, parts produced by FFF frequently suffer from relatively poor surface finish and limited dimensional accuracy. Therefore, the application of appropriate post-processing techniques has become essential to enhance the surface characteristics and dimensional integrity. Among the available methods, laser beam cutting (LBC) has emerged as a promising non-contact post-processing technique, capable of improving cutting precision and surface quality. This research outlines post-processing techniques for polylactic acid–wood (PLA–wood) composites fabricated by FFF using LBC. The impacts of input parameters—laser speed (LS: 10, 15, and 20 mm/s), laser power (LP: 60, 72, and 84 W), and infill percentage (IP: 10, 50, and 90%)—on the upper kerf width (UKW), lower kerf width (LKW), ratio of UKW to LKW, and heat-affected zone (HAZ) were investigated using a full factorial design. The relationships between the input factors and response variables were analyzed using multiple regression models, and the reliability of the resulting regression equations was evaluated through analysis of variance (ANOVA). The results indicate that LP is the most influential parameter affecting both the UKW and LKW, while the IP has the strongest influence on the kerf ratio and the HAZ. UKW and LKW decrease with increasing LS and IP, while they increase with higher LP. The most uniform kerf, defined as the ratio UKW/LKW closest to 1.0, was obtained with a ratio of 0.921 at an LS of 20 mm/s, an LP of 84 W, and an IP of 90%. The maximum HAZ of 481.601 µm occurred at the lowest LS of 10 mm/s, the highest LP of 84 W, and the highest IP of 90%.