Effect of wood content in FDM filament on properties of 3D printed parts

The effect of wood content in 3D printing materials on the properties of 3D printed parts was investigated. Six filaments using polylactic acid (PLA) with varying loading levels of wood particles from 0% to 50% by weight were produced and used for 3D printing. The density of the filaments and 3D printed parts used in this study slightly decreased with increasing wood content. The tensile strength of the filaments increased from 55 MPa to 57 MPa with an addition of 10% wood, but decreased with higher levels of wood content to 30 MPa for filaments with 50% wood content. The surface of the parts printed from the filament without the addition of wood was smoother and the printed part had no voids within the structure. With increasing wood content the surface becomes rougher, more voids were present, and had visible clusters of wood particles (due to wood particle clustering and clogging in the printer nozzle). Higher wood content in 3D printed parts decreased the storage modulus. measured with torsional loading on a rheometer, but did not change the glass transition temperature.