Effect of infill pattern and filler ratio on the mechanical properties of 3D printed eco-friendly wollastonite/polylactic acid composites

The present study aims to study the effect of various infill patterns (Rectilinear, Triangular, and Honeycomb) on the mechanical properties of 3D-printed polylactic acid (PLA) composites by reinforcing the wollastonite mineral fillers at 2, 4, and 6 wt% ratios. The triangular infill pattern printed samples displayed the highest tensile and flexural properties due to the fact that trigonal unit topologies exhibit more serrated cycles than rectilinear ones. Units with a triangle infill pattern are stiffer and less ductile than those with honeycombs. Tensile and flexural modulus values are therefore shown to increase in tandem with an increase in the filler ratio. The impact strength analysis showed that the rectilinear pattern performed better regarding energy absorption. The hardness values were found to increase as the filler ratio due to the particle’s rigidity, which made it impossible to resist the indentation deformation on the surface. The triangle pattern samples show no signs of deformation fracture, and appeared with smooth fractured surface in the morphologies. Comprehensively, this study confirms that the triangular infill pattern outperformed in mechanical properties as compared to honeycomb and rectilinear patterns in 3D printed wollastonite reinforced PLA composites, and could be suggested for lightweight frictional materials applications.