Enhanced Performance 3‐D Printed PLA Parts through a Photo‐Initiator Mediated UV‐Curing

Abstract The fused deposition modeling or three‐dimensional (3D) extrusion fabrication of material parts from thermoplastics, including poly(lactic acid) (PLA) usually results in inferior mechanical performance due to weak inter‐layer bonding compared to injection molded parts. In this work, a solvent‐free, effective, and inexpensive method is developed by incorporating photo‐initiators during a 3D extrusion fabrication followed by a post‐process UV treatment to improve the 3D‐printed PLA part's performance. This developed method addresses key challenges of 3D printed PLA parts, such as poor toughness and UV sensitivity, while enabling its use in high‐performance additive manufacturing (AM) processes. The UV‐curing process enhances PLA's suitability for 3D printing, supporting complex geometries and custom designs by enhancing the crosslinking between adjacent PLA chains, under UV exposure. The solvent‐free nature of the developed process aligns with sustainable manufacturing, strengthening PLA's role as an eco‐friendly alternative to petroleum‐based polymers. A standout result of this approach is the 64% improvement in tensile properties of PLA with the photo‐initiator and UV treatment samples compared to untreated PLA, achieved through UV‐curing. This advancement overcomes the persistent issue of weak interlayer bonding in the 3D printing of PLA and positions PLA as a viable material for sustainable and high‐performance applications.