Advancing Circularity in Additive Manufacturing: Life Cycle Assessment of Post-Consumer PA12 Recycling

Resumo

Additive Manufacturing (AM) has emerged as a transformative technology in industrial production, enabling the fabrication of complex geometries with reduced material waste compared to conventional methods. Among its techniques, Powder Bed Fusion (PBF) is widely applied to polymeric materials such as polyamide 12 (PA12), producing durable components that eventually reach end-of-life. The growing volume of discarded AM parts highlights the need for sustainable end-of-life strategies, with mechanical recycling offering a promising pathway to close material loops within a circular economy. This study evaluates the environmental performance of post-consumer PA12 recycling from prototypes and parts manufactured via PBF using the HP Multi Jet Fusion 5210 printer. The assessment followed ISO 14040 and 14044 guidelines, adopting a cradle-to-gate boundary and a functional unit of 1 kg of recycled PA12 pellets (PA12r). Data were based on primary measurements at SENAI/CIMATEC’s facilities, complemented by secondary datasets from Ecoinvent 3.10.1. The product system comprised five stages: Cascalheira Milling, Cimatec Park Milling, Manual Washing, Drying, and Extrusion/Pelletizing. Life Cycle Impact Assessment (LCIA) results, focused on Global Warming Potential (GWP100, IPCC 2021), showed PA12r achieved a 10% carbon footprint reduction compared to virgin PA12. Drying was the most impactful stage in total emissions, while Extrusion/Pelletizing had the highest hourly rates, underscoring their critical roles in optimization. Electricity consumption was the dominant contributor, influenced by equipment demand and Brazil’s energy mix. Findings show the technical and environmental potential of scaling PA12 recycling for additive and
conventional manufacturing, while addressing a literature gap and supporting recycling integration in AM supply chains to boost circularity and reduce impacts.