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The objective of this work is to evaluate the reprocessing of PLA 3D printing waste from different origins, into filaments and films, and without the addition of any additive. Two types of waste were considered: a blend of different printing wastes (masks, visors, other components) of personal protective equipment coming from an association of Spanish coronamakers, and PLA waste from a single known commercial source. Both types of materials were subjected to repeated extrusion cycles and processed into films by compression molding. Samples were characterized after each cycle and their mechanical and viscosity properties evaluated. Diffusion-ordered NMR spectroscopy (DOSY) experiments were also carried out to estimate molecular weights. The results show a better performance for the PLA waste from the known origin, capable of withstanding up to three re-extrusion cycles per two for the waste blending, without significant degradation. Additionally, a model to address collection and mechanical recycling cycles under two different scenarios (full traceability and not full traceability) was proposed.

3D printing PLA wastes were recovered from a well-known reference grade and from different sources. The recovered wastes were subjected to an energic washing step and then reprocessed into films by melt-extrusion, followed by compression molding to simulate the industrial processing conditions. The obtained materials were characterized and the optical, structural, thermal and crystallization behavior are reported. The mechanical recycling process leads to an increase of the crystallinity and a decrease of the intrinsic viscosity of the formulations, particularly in the sample based on blends of different 3D-PLA wastes. Moreover, the obtained films were disintegrated under composting conditions in less than one month and it was observed that recycled materials degrade somewhat faster than the starting 3D-PLA filament, as a consequence of the presence of shorter polymer chains. Finally, to increase the molecular weight of the recycled materials, the 3D-PLA wastes were submitted to a solid-state polymerization process at 110, 120, and 130 °C, observing that the recycled 3D-wastes materials based on a well-known reference grade experiences an improvement of the intrinsic viscosity, while that coming from different sources showed no significant changes. Thus, the results show that 3D printing PLA products provides an ideal environment for the implementation of distributed recycling program, in which wastes coming from well-known PLA grades can successfully be processed in films with good overall performance.

Textiles waste is relatively small in terms of weight as compared to other waste streams, but it has a large impact on human health and environment, and its rate is increasing due to the 'fast fashion' model. In this paper, we examine the French national programme for managing post-consumer textiles and clothing through a case study research. To date, France is the only country in the world implementing an extended producer responsibility (EPR) policy for end-of-use clothing, linen and shoes. The case highlights the benefits of using an EPR policy and provides interesting insights about the challenges faced by the textiles waste sector. For instance, the EPR policy has contributed to a threefold increase in the collection and recycling rates of post-consumer textiles since 2006. In addition, the material recovery rate of the post-consumer textiles can reach 90%, 50% of which can be directly reused. However, the 'reuse' stream is facing some challenges because its main market is in Africa and many African countries are considering banning the import of used textiles to encourage a competitive textiles industry locally and internationally. The EPR policy shows a great potential to identify new markets for 'reuse' and to improve the textiles waste sector. Such an EPR policy also could drive societies to financially support innovation and research to provide feasible solutions for fashion producers to adopt eco-design and design for recycling practices. This paper provides guidance for policy makers, shareholders, researchers and practitioners interested in diverting post-consumer textiles and clothing waste from landfills and promoting circular textiles transition.