Comparative Performance Analysis of Polylactic Acid Parts Fabricated by 3D Printing and Injection Molding

Abstract

In the present experimental investigation, the specimens were fabricated using 3D printing (fused deposition modeling) and injection molding techniques. The process parameters were optimized to fabricate the good quality polylactic acid (PLA) specimens as per ASTM standards. The effect of variation (80, 90, and 100%) of the infill density on the mechanical performance of developed specimens was analyzed. The mechanical behavior of the fabricated specimens was compared in the context of tensile, flexural, and impact properties. The thermal stability and crystallinity of the PLA specimens have been investigated using thermogravimetric and XRD analysis, respectively. After tensile testing, the surface of the fractured specimens was observed using a scanning electron microscope. The tensile and flexural strength of the 3D-printed specimens was superior to the injection-molded specimens. An improvement in stiffness of the 3D-printed specimens has been observed. Moreover, the printed specimens showed better thermal stability than the molded specimens. There was no significant variation in the crystallinity of the printed and molded specimens. It can be concluded that the tensile, flexural, and thermal responses of the 3D-printed specimens are better than injection-molded specimens at the optimal combination of process parameters. © 2021, ASM International.