Comprehensive study of PLA material extrusion 3D printing optimization and its comparison with PLA injection molding through life cycle assessment

The rapid growth of additive manufacturing has been instrumental in advancing science and technology. Material Extrusion (ME) 3D Printing is a widely used additive manufacturing process, offering satisfactory results through parameter optimization. This process, known for its cost-effectiveness and ability to produce complex geometries, is widely used across various industries, from automotive to biomedical applications. In this study, we focus on analyzing key ME 3D printing parameters. Polylactic acid (PLA) is an ideal choice for 3D printing due to its renewable nature, low melting point, and minimal carbon footprint, ensuring stable and predictable mechanical properties for industrial and medical parts. PLA's biodegradability and availability as a filament make it a popular choice in the additive manufacturing industry. Our goal is to establish correlations between material characteristics, mechanical properties, and printing parameters using PLA as the base polymer through ANOVA analysis. The results show that optimized parameters, including a printing temperature of 220 degrees C and specific post-processing conditions, yield impressive outcomes. The ME 3D Printing machine achieved a 98 %-dimensional accuracy and enhanced strength, with PLA exhibiting a tensile strength of 38.9 MPa, which further increased to 55.9 MPa during post-processing (heating at 60 degrees C). Additionally, we provide a detailed mechanical and morphological properties comparison between ME 3D printed and injection molded samples. Life cycle assessment (LCA) analysis of optimized 3D printed PLA was compared with its injection-molded counterpart to evaluate their environmental sustainability and identify potential areas for improvement in manufacturing processes and resource utilization. Furthermore, we emphasize the importance of standardized terminology in the ME 3D Printing process.