Indirect 3D Printing of recycled glass fibres from end-of-life products: towards a design engineering approach to circular design

Sustainability is increasingly becoming a key aspect for the design of new products and services. Within this context, digital technologies represent a reliable way for the development of new circular economy models. Basically, Additive Manufacturing (or 3D printing) allows to implement not only distributed production strategies but also the reuse and recycle of products at their end of life. In the last years, the development of new recycled materials for additive manufacturing has received much attention from both industry and academia, especially considering the most common materials (i.e. thermoplastics). Only few studies are actually focused on the recycling of less conventional products and wastes, as in the case of glass fibre composite materials. Since recycled fibres shall often fulfil specific requirements for the development of a new 3D printable material, coarse recycled fibres are not generally considered for the design of new products with additive manufacturing. Furthermore, designers are not fully aware of the existence of these new recycled materials, and their potential use for new applications may not be completely figured out during the design process. Especially for recycled composites, new materials are usually developed considering quantifiable physical properties as a priority at the expense of expressive-sensorial qualities related to human perception. How could the use of these circular materials be encouraged for the design of new products? Is it possible to develop new recycled materials for real applications by considering a different approach to additive manufacturing? The aim of this work is to define a strategy for the design and production of new products from recycled composites through low cost and accessible 3D printing technologies. 20th European Round Table on Sustainable Consumption and Production Graz, September 8 – 10, 2021 Firstly, a new thermally-curable epoxy-based material filled with coarse shredded end-of-life wind blades was characterised taking in consideration both physical and expressive-sensorial qualities. At this purpose, a preliminary mechanical characterisation was performed, as well as different samples were created and compared according to the main visual and tactile properties. Contemporarily, a suitable process for the production of customizable pieces was defined through an indirect approach, which means by pouring the material in moulds made from a Fused Filament Fabrication 3D printer (Indirect 3D Printing). Afterwards, the whole experimentation was validated thanks to the design and prototyping of a product for temporary exhibitions and stands, which can be reused as urban furniture or interior design element after its life cycle. To conclude, this strategy allows to design and produce customized long-lasting products from a waste-based material with an accessible technology, giving to the designer more flexibility for the development of new sustainable solutions. Further efforts should be done in order to better define an integrated approach for the development of new circular materials merging product design and material engineering expertise. In addition, other end-of-life products and materials could be potentially considered, as well as the use of biobased matrixes. Finally, the use of low-cost additive manufacturing technologies may lead to new bottom-up circular economy models for real applications from end-of-life products and common wastes.