Energy-saving approach for mechanical properties enhancement of recycled PET additively manufactured by MEX

This study investigates the recycling of polyethylene terephthalate (PET) water bottles by material extrusion (MEX), an additive manufacturing (AM) technique, with a focus on characterising energy consumption and mechanical properties throughout the recycling process. The process encompasses shredding of the bottles, filament production, and the printing of tensile specimens. A full factorial design of experiment (DoE) was used to investigate the impact of various process parameters on product quality from an energy-saving perspective. The results provide important insights into energy efficiency and mechanical performance, identifying the optimal production conditions that balance environmental sustainability and material functionality. The results show that by optimizing printing parameters, energy consumption can be reduced by up to 30%, while the tensile strength of the printed samples can be increased by 20%. This research contributes to a broader understanding of the potential for AM in PET recycling, providing a pathway towards more localized and sustainable manufacturing practices.