Environmental, Technical, and Circular Assessment of the Integration of Additive Manufacturing and Open-Loop Recycling of PET

Polyethylene terephthalate (PET) is one of the most widely used plastics globally, and its poor post-consumer management poses serious risks to the environment and human health. Tackling this issue requires innovative strategies that combine recycling and sustainable manufacturing with the principles of the circular economy. This study addresses this challenge by investigating the use of recycled PET, along with reverse logistics, to produce a cell phone holder through additive manufacturing (AM). Characterization was performed using differential scanning calorimetry, thermogravimetric analysis, intrinsic viscosity measurements, and mechanical tensile tests. Environmental and circular performance were evaluated using Life Cycle Assessment (LCA) and the Material Circularity Indicator (MCI), comparing production with 100% virgin PET resin and 100% recycled PET resin. The results showed that the recycled route achieved a tensile strength of 37.7 MPa, with 7.6% strain before rupture, and thermal analysis confirmed its stability during processing. The LCA revealed a 12% reduction in overall environmental impacts when recycled PET replaced virgin resin, with electricity consumption identified as the main critical point. The circularity assessment suggested potential savings of up to 70% if recycled PET products are reprocessed at the end of their life cycles. These findings demonstrate that combining open-loop recycling with additive manufacturing (AM) can effectively turn waste into high-quality, value-added products, advancing circularity and sustainable material innovation.