Poly(lactic acid) (PLA) is the most widely used feedstock in material extrusion (MEX) 3D printing. In this study, PLA was combined with 0-40 wt.% of poly(butylene adipate-co-terephtalate) (PBAT) to improve its ductility. The resulting blends were processed into filaments suitable for MEX 3D printing and used to fabricate specimens for mechanical characterization using three distinct raster angles (RAs; 0°, ±45°, and 90°) to statistically evaluate the individual and joint effects of blend composition and raster orientation. Melt flow index (MFI) measurements showed that increasing PBAT content reduced the MFI from 40.4 g/10 min to 34.4 g/10 min, which led to weaker bonding between printed beads, as shown in scanning electron microscopic images. Tensile strength, modulus, and impact strength were evaluated using tensile and Charpy tests. Statistical analysis showed that RA, PBAT concentration, and their interaction all significantly influenced (p 2) was found at 40 wt.% PBAT content and ±45° RA.
Jakab et al. (Tue,) studied this question.