Effect of raster angles on mechanical properties and failure analysis of 3D printed Tamarindus indica seed powder/ polylactic acid (PLA) biocomposites

The concern of fruit wastes, deteriorating environmental condition, exhausting natural resources and high-cost of conventional materials are the global worriment. The recycling of fruit wastes in the development of biocomposites promotes circular economy in modern industries. 3D printing or additive manufacturing (AM) is a cutting-edge technique for the development of complex and customized components with minimal wastage of material and requires less production time. The workability of additively manufactured products can be improved by suitable printing parameters. This research aimed to explore the effect of 3D printing parameter namely, raster angle on the mechanical performances of biocomposites. 3D printed specimens were developed by the reinforcement of 20 wt.% of tamarindus indica seed powder as biofillers with 80 wt.% of polylactic acid (PLA) having raster angles of 0°, 30°, 45°, 60° and 90°. The investigation on mechanical properties such as flexural strength, tensile strength, stress-strain behavior of the specimens were performed. The tensile and flexural strength and stress-strain responses of the biocomposites was found to influence by the change in the raster angles. The experimental results has showed a significant increase in tensile strength at 45° and 60° raster angles of 22.1 ± 1.502 MPa and 22.2 ± 1.554 MPa respectively while the optimal flexural strength was found to be 41.0 ± 2.870 MPa at 45° raster angle. The analysis of stress-strain behavior has observed ductile failure patterns characterized by an initial linearity followed by non-linearity and steeper slopes with increasing raster angle. The consistent slope without sharp fluctuations shows a stable yielding and subsequent failure. The minor stress fluctuations were attributed to micro-crack initiation, filler-matrix debonding and void coalescence during loading. The research highlight the significance of raster angles and stress-strain responses in optimizing the flexural and tensile strength of 3D-printed composites under flexural and tensile loads. • Tamarindus Indica seed powder and Polylactic acid in biocomposites. • Valorization of fruit waste into efficient biofillers with a biodegradable polymer. • Effect of raster angles on mechanical properties of 3D-printed biocomposites. • Stress-strain response of biocomposites at different raster angles. • Morphological analysis of the fractured surfaces.