Comparison of mechanical properties of 3D-printed and compression-molded wood-polylactic acid (PLA) composites

Abstract

Mechanical properties of materials obtained by compression-molding were compared with three-dimensional (3D) printed materials. Firstly, wood flour was added at different levels (0, 5, 10, and 20%) to polylactic acid (PLA) polymer to produce filaments. Then, mechanical test samples were printed from the produced filaments with a 3D printer. The produced filaments were made into pellets, and sheets were obtained by compression molding. According to the mechanical test results, it was observed that the tensile strength of the 3D-printed and compression-molded materials were close to each other, and the elasticity modulus of the compression-molded samples was higher than the 3D-printed samples. In the hardness comparison, the compression-molded specimens exhibited higher hardness values than the 3D-printed specimens. When the morphological properties of the materials were examined, it was seen that the cross-sections of the compression-molded materials were smooth and had less void than the 3D printed ones. The glass transition, crystallization, and melting temperatures of the materials did not change much with the processing methods. Only the 3D-printing process increased the crystallinity percentages.