A SUSTAINABLE APPROACH TO RECYCLING WASTE: EXAMPLES OF THE APPLICATION OF 3D PRINTING TO EXTEND THE LIFE CYCLE OF MATERIALS

Abstract

The environmental questions emerged in recent decades have caused a transition from a linear economy, which involves the extraction of raw materials, production, distribution, consumption and final disposal of a good, to a circular economy (CE). CE is based on the reuse of materials in subsequent production cycles by extend-ing their useful life, with the aim of reducing and if possible, eliminating any waste. Fused Filament Fabrication (FFF), a 3D printing technique, has emerged in recent years as a promising methodology for green and sustainable purposes. The use of natural and biocompostable materials for the production of filaments for FFF, such as poly(lactic acid) (PLA), has made this 3D printing technique one of the most promising in several fields. Furthermore, scientific research is focusing on improving the sustainability of primary materials used in 3D printing, through the development of composite filaments from green or recycled materials. This paper presents some applications concerning the development of innovative and sustainable materials focused on reducing the environmental impact of conventional FFF materials, car-ried out in recent years in our laboratories. In particular, various composite filaments incorporating poly(lactic acid) (PLA) and different handicraft or agro-industrial waste materials, including olive wood waste (OW), cocoa bean shell waste (CBSW), ce-ramic waste (CW) and Lecce stone waste (LSW), have been produced by extrusion. A comprehensive analysis was conducted on the innovative biocomposites devel-oped, including structural, morphological, thermal and mechanical evaluations, and the comparison of the results obtained with the different subproducts is presented in the paper. Finally, some simple real objects first reproduced manually, were later 3D printed using the developed biocomposite filaments, demonstrating the effective-ness of FFF in successfully recycling artisanal and agro-industrial waste within the same production company, reducing costs and supporting the CE.