Review of physical and solvent recycling of automotive plastics underlines complexity of sorting and technical challenges. An average car today in 2019 contained already c. 160 kg of plastics (nearly 9% of its weight), of which around 50% in the car interior, nearly 30% under the hood and electrics and 20% vehicle exterior. The EU End-of-Life Vehicle (ELV) Regulation sets a recycling target of 85% of vehicle weight. Sorting of ELV plastics is complicated because a range of polymers are used, parts are often bonded to other materials, and composites contain fibres and different additives (stabilisers, antioxidants, antistatics, colours, fillers, flame retardants). Current automatic sorting methods only enable separation into groups of similar materials and manual sorting is prohibitively expensive. Pre-treatment before recycling also involves shredding to small particle sizes and washing to remove contaminants (dirt, fuels and fluids). Physical recycling is discussed, noting that mechanical properties tend to deteriorate with breakage of the polymer molecules and fibres. Examples of solvent recycling are presented, noting that to date these tend to target recovery of carbon fibres rather than plastics.
“A mini-review of the physical recycling methods for plastic parts in end-of-life vehicles”, V. Martinez Sanz et al., Waste Management & Research 2022, Vol. 40(12) 1757–1765, https://dx.doi.org/10.1177/0734242X221094917