Characteristics of Unidirectional Green Wood Fiber/Polylactic Acid Composite Parts Printed with Various Layer Thicknesses by Fused Filament Fabrication

3D Print Addit Manuf. 2021 Oct 1;8(5):322-330. doi: 10.1089/3dp.2020.0210. Epub 2021 Oct 8.

Abstract

In this study, the effect of layer thickness on the physicomechanical properties of the wood fiber-polylactic acid composite (WPC) part obtained by fused filament fabrication (FFF) was investigated. The results showed that most of the characteristics of the FFF-printed WPC part significantly depended on the printing layer thickness. As the layer thickness increased, the density of the printed WPC part decreased significantly, while the dimensional stability of the water-immersed WPC part decreased. In addition, specific tensile properties increased and the other specific mechanical properties (flexural, compressive, and shear properties) decreased with increasing layer thickness. Furthermore, scanning electronic microscopy micrographs illustrated that the number of voids and defects was more often observed on the surface of the WPC part printed with higher layer thickness. Therefore, these results indicated that the different layer thicknesses in FFF manufacturing have a substantial impact on the dimensional stability and specific mechanical properties of the FFF-printed WPC part.

Keywords: dimensional stability; fused filament fabrication; layer thickness; mechanical properties; wood fiber–PLA composite.