A Critical Review of the Discrepancies in PLA Recycling for 3D Printing

This review examines the recycling of Polylactic acid (PLA) filament for 3D printing, focusing on mechanical and chemical property retention after repeated reprocessing. The study evaluates PLA waste from diverse sources, including PPE production, analyzing mechanical strength, molecular weight, and crystallinity changes across extrusion cycles. PLA recycling challenges include chain degradation, decreased tensile strength, and increased fluidity with repeated heating, though properties may be improved through polymer alloying. A detailed recycling system design is also proposed, incorporating temperature control, stepper motor regulation, and quality monitoring for efficient filament production. This system supports sustainable, high-quality PLA recycling for 3D printing applications.