Assessment of 3D printing using fused deposition modeling and selective laser sintering for a circular economy

Plastic today is commonplace. Products and parts made with plastic have short life cycles, ending up in landfills not long after manufacture. Finding new pathways for plastic waste has become a critical focus of sustainability efforts, especially within manufacturing. Thus, research in this field continues to grow in order to determine the feasibility of reclaiming post-consumer plastic for reuse. This paper evaluates the potential for a sustainable, circular pathway for end-of-life plastic material using 3D-printing techniques. To do this, the work investigates two prevalent industrial 3D-printing technologies: selective laser sintering (SLS) and fused deposition modeling (FDM) of polymers. Material-flow and economic models are developed to outline how plastic parts at the end of their life cycle can be processed and reused. Prior works on fundamental material degradation are integrated into mathematical models of cost and operation. This enables mapping of how multiple reuse cycles affect two prevalent industrial polymers: acrylonitrile butadiene styrene (ABS) and polyamide 12 (PA 12). The mapping identifies there is significant opportunity for improving both SLS and FDM 3D-printing technologies when it comes to economic viability and sustainability. Comparison between reuse of FDM using ABS and SLS using PA 12 shows the former costs 82% less than the latter, while also producing 87% less waste than it. While the study established that available industrial 3D-printing technologies can help to reduce plastic waste within manufacturing, a fully circular economy demands materials with less thermal degradation than the primary industrial 3D-printing polymers.