ABSTRACT
It is generally recognized that the use of physical and digital information-based solutions for tracking plastic materials along a value chain can favour the transition to a circular economy and help to overcome obstacles. In the near future, traceability and information exchange between all actors in the value chain of the plastics industry will be crucial to establishing more effective recycling systems. Recycling plastics is a complex process that is particularly complicated in the case of acrylonitrile butadiene styrene (ABS) plastic because of its versatility and use in many applications. This literature study is part of a larger EU-funded project with the acronym ABSolEU (Paving the way for an ABS recycling revolution in the EU). One of its goals is to propose a suitable traceability system for ABS products through physical marking with a digital connection to a suitable data-management system to facilitate the circular use of ABS. The aim of this paper is therefore to review and assess the current and future techniques for traceability with a particular focus on their use for ABS plastics as a basis for this proposal. The scientific literature and initiatives are discussed within three technological areas, viz., labelling and traceability systems currently in use, digital data sharing systems and physical marking. The first section includes some examples of systems used commonly today. For data sharing, three digital technologies are discussed, viz., Digital Product Passports, blockchain solutions and certification systems, which identify a product through information that is attached to it and store, share and analyse data throughout the product's life cycle. Finally, several different methods for physical marking are described and evaluated, including different labels on a product's surface and the addition of a specific material to a polymer matrix that can be identified at any point in time with the use of a special light source or device. The conclusion from this study is that the most promising data management technology for the near future is blockchain technology, which could be shared by all ABS products. Regarding physical marking, producers must evaluate different options for individual products, using the most appropriate and economical technology for each specific product. It is also important to evaluate what information should be attached to a specific product to meet the needs of all actors in the value chain.
ABSTRACT
Polyethylene is a commonly used polymer in plastic products and is often found as marine litter. Nevertheless there is limited knowledge about what happens to the material when it ends up in the sea. Polyethylene films were therefore thermally oxidised to four different levels of degradation. The films were then placed in stainless-steel cages in the sea off the Swedish west coast for 12 summer weeks. Subsamples were analysed with respect to biofouling, degradation and buoyancy. All levels showed a continued oxidation in the field. The pre-degraded films started fragmenting and the non-degraded films showed a decrease in tensile strain. All levels showed increased biofouling with higher presence of filamentous algae and bryozoans on pre-degraded materials. The density (kg·m-3) of the films was seen to increase slightly, and the apparent density for the pre-degraded films (density of the films with biofilm) showed a strong increase, which resulted in sinking.
