Remanufacturing using end-of-life vehicles and electrical and electronic equipment polymer recyclates - a paradigm for assessing the value proposition

Abstract

Over 400 million tonnes of plastics are produced on earth every year and are the most used materials on the globe. As a result, polymeric material-based waste has been accumulating, and now can be found not only in designated waste tips on land, but also as pollution all over the world. Therefore, it is timely to accelerate global recycling plans to minimize the use of natural resources. At present, end-of-life vehicles (EOLV) and electrical and electronic equipment (EEE) are two major sources of waste. Such waste includes a combination of polymers, which are hard to separate. Because the properties of blends of polymer are not well-understood, the recycling opportunities for such wastes are hindered. Hence, this paper aims to extend the knowledge concerning the re-processing of such recycled polymers, as a first step towards developing a more effective circular manufacturing economy. Three types of recycled polymers were tested under various processing conditions, and the effects of six different process parameters were investigated, including chip size and morphology. The results confirm that properties and processing behaviour of recycled materials can be highly variable, and hence difficult to predict. This highlights the importance of better selection and screening of scrap polymers, to remove undesirable content from the material batch. Knowing the exact constituents of each batch of material to be recycled means that appropriate process settings can be selected, to achieve better material properties in the recycled end product. In addition, energy and materials costs can be reduced by optimizing process parameters such as the set temperatures, pressures, and product dimensions. Tests carried out with different recycled polymer chip sizes indicate that size grading would be worthwhile, as would the reforming of chips to flattened discs or strings. Such additional processing could represent considerable value proposition to the recycled material preparation industry.