State-of-the-art review on fused deposition modeling (FDM) for 3D printing of polymer blends and composites: innovations, challenges, and applications

Fused Deposition Modeling (FDM) is a critical technology in Industry 4.0, offering sustainable solutions for manufacturing engineering products, agricultural tools, biomedical implants, and packaging. However, the mechanical performance of 3D-printed parts, particularly those made from polylactic acid (PLA) and its blends, often lags behind conventional materials. This review critically examines the key parameters affecting PLA's mechanical behavior and its FDM blends. We explore how material modifications and advanced additive manufacturing techniques can improve complex geometries' functionality, mechanical properties, and environmental adaptability. While numerous studies exist on PLA blends, a comprehensive review of design, modeling, and evaluation strategies remains lacking. This paper addresses that gap, providing an in-depth analysis of recent advancements in PLA blends, their applications, and challenges in fields like biomedical devices, soft robotics, and food packaging. Our findings highlight the transformative potential of PLA blends and propose future research directions to enhance FDM-printed composite structures.