Sustainable additive manufacturing: A review on 3D printing using recycled waste polymers

The exponential increase in polymer waste, which is a result of the widespread use of plastics in various sectors, has resulted in severe environmental issues due to the fact that polymers are not biodegradable. This research focuses on the development of sustainable bio composites that are made from natural waste materials and recovered polymers. Additionally, it investigates the most recent developments in the recycling of polymer waste through additive manufacturing (AM) and 3D printing (3DP). A mixed-methods approach, which encompassed expert interviews and a comprehensive literature review, was employed to identify current practices, challenges, and opportunities. The research addresses a variety of significant challenges, such as thermoset reprocessing, contaminants, additives and coatings, ineffective separation, complex chemical compositions, and mechanical, chemical, and thermal recycling methods. The paper emphasizes the potential of recycled polymers to be employed in additive manufacturing processes, such as fused filament fabrication (FFF), as well as their application in healthcare, building, and consumer goods, in order to produce affordable, environmentally responsible products. This investigation advocates for decentralized recycling systems that facilitate local production, reduce resource extraction, and mitigate environmental damage by aligning AM with circular economy principles. The final section of the report identifies the areas that require additional research and provides suggestions for the development of sustainable 3DP technologies to facilitate the transition to a zero-waste future.