Development of short basalt fiber reinforced polylactide composites and their feasible evaluation for 3D printing applications

The objective of this work is to develop KH550-treated basalt fiber (KBF) reinforced polylactide (PLA) composite as a potential 3D-printed feedstock. Herein, physical (thermal, mechanical, and rheological) properties and the feasibility of PLA/KBF for 3D printing are investigated. KBF is found to be oriented-dispersed along the printing direction in printed specimen, in contrast with randomly-distributed KBF in casting counterparts. Mechanical tests, rheological behavior and microstructure observation of PLA/KBF filaments are performed to compare with carbon fiber (CF) reinforced counterparts with the same fiber weight fraction. The results suggest that PLA/KBF exhibit comparable tensile properties and superior flexural properties to those of PLA/CF control, which can be attributed to high complex viscosity of PLA/CF affecting the interlayer adhesion. Furthermore, the printing feasibility of PLA/KBF filaments are evaluated. With increasing fiber length and weight fraction of KBF, low infill and micro-defects are shown in CT scans, which explain the deterioration in mechanical performance. The present work proves PLA/KBF as a mechanical-improved and low-cost feedstock for 3D printing applications in complex design and variable sizes.