Managing challenging waste fractions: Mechanical recycling of router housings from WEEE and environmental assessment

Waste streams consisting of various materials pose significant challenges for mechanical recycling processes. Discarded router casings are a relevant example of this, as they are typically processed via conventional waste electrical and electronic equipment (WEEE) recycling channels, which often involve the energy recovery of mixed plastic fractions. This study assesses both the technical feasibility and the environmental sustainability of the mechanical recycling of real router casings. A recycling process was developed comprising pre-shredding, shredding, pelletisation and extrusion to produce an acrylonitrile-butadiene-styrene and polycarbonate (ABS/PC) recyclate. The material was compared with commercially available recyclates of the same polymer type in terms of melt flow rate and mechanical properties, including tensile strength, tensile modulus and impact strength. The results show that the recycled material exhibits suitable melt flow properties and comparable or improved mechanical performance. Furthermore, a life cycle assessment (LCA) was carried out to compare the environmental impacts of the proposed recycling process with conventional treatment routes, such as incineration with energy recovery. Whilst conventional treatment methods may have a lower net impact due to energy credits, mechanical recycling can achieve a negative net environmental impact if the recycled material replaces virgin polypropylene in suitable applications. Overall, the results demonstrate the technical feasibility and environmental potential of recycling router housings, but also highlight limitations regarding the variability of product design, data availability and the transferability of the approach to other plastic fractions from waste electrical and electronic equipment.