Three-dimensional (3D) printing is an emerging technology that is transforming manufacturing
technology due to its unique advantages such as freeform fabrication, sustainability, and
efficient manufacturing. In this study, we developed a wood flour (WF)/polylactic acid (PLA)
composite filament for fused deposition modeling (FDM) 3D printing and analyzed its composite
properties. Results showed that the tensile strength of the WF/PLA composite was considerably
less than that of neat PLA. By adding 10 wt% of thermoplastic polyurethane (TPU) as a toughening
agent, the elongation-at-break value of the WF/PLA composite was greater than that of neat
PLA. This shows that the toughening agent could increase the ductility of the WF/PLA composite,
leading to a better printing experience. We found a significant relationship among extrusion temperatures
and dimensional stability of printed objects, whereas the surface roughness of specimens
increased as the extrusion temperatures increased. A higher infill rate and greater extrusion layer
height were both shown to give the printed object better dimensional stability.