Plastic is a synthetic material, made from organic polymers, that has become essential in current supply chains due to its beneficial properties – light weight, durable and easily shaped – and low cost.
Since the 1960s, plastic production has increased by 20 times, with a global manufacture of 360 million tonnes in 2018, 40% of which were used for packaging (PlasticsEurope, 2019). Accordingly, plastic waste has been also increasing. In EU27, plastic waste almost doubled since 2004; with a total amount of 17 million tonnes in 2018 (EUROSTAT, 2018). The global concern of plastic waste pollution has been growing, and political actions have been taken to reduce it, such as the approval of the EU Directive 2019/904 to ban some single-use plastic products from July 2021 and the European strategy for plastics.
Including circular strategies when designing plastics is essential. In this regard, Bocken et al. (2016) defined three key strategies: (1) slowing resource loops, by extending the product-life (reusing); (2) closing resource loops through the recycling of resources; and (3) narrowing resources flows, by enhancing resource use efficiency. While the third strategy is not strictly considered as a circular strategy, since it can be applied to linear models, the other two are circular-based approaches. Focusing on the case of Reusable Plastic Crates (RPCs), they are already designed for extending their product-life, by being able to be reused, maintained and repaired; but little has been published on their design to close resource loops. Hence, this article will focus on the recycling strategy when designing RPCs.
As defined by the European Commission, recycling is “any recovery operation by which waste materials are reprocessed into products, materials or substances whether for the original or other purposes”. Based on the quality of the final product, four types of recycling can be defined (Merrington, 2011): (1) Primary, or closed-loop, recycling, in which the recovered material has the same function as the virgin one, and it is used for the same purposes; (2) Secondary, or open loop recycling, where the recovered material is used to produce other products with lower properties than the original one; (3) Tertiary, or chemical, recycling, where chemicals from the plastic waste are extracted and used to produce goods of the same properties, and (4) Quaternary recycling, which is related to energy recovery. However, the recycling of waste in the EU does not consider the tertiary and neither the quaternary.
Moreover, based on the source of the material, the recycled plastics can be classified by the source of the material, as post-industrial (being collected at the manufacturer) and post-consumer. Recycling postindustrial plastics have more advantages since they are cleaner, homogeneous and controllable, while the postconsumer plastics are a mix of plastics that must be sorted between recyclables and non-recyclables, and properly cleaned to the able to keep a good quality to make new products. This is even stricter when the recovered material is used for food packaging, especially for those that are in contact with the produce, as reviewed by Matthews et al. (2021).
In the case of the RPCs of pooling systems for fresh foods, such as the one integrated by ARECO, crates are recycled once they (or parts of them) are damaged and arrive at the end of their life. However, different post-industrial recycling systems exist. One system consists of an open-loop recycling, where the crates are sent back to the manufacturers, who recycle the RPCs and use the secondary granulates to produce other type of products. The second system consists in the poolers sending back the crates to the manufacturers for closed-loop recycling; so the secondary granulates are used to produce, partially (with virgin material), new crates. The third case is the in-house closed-loop, meaning that the pooler is capable to recycle and fully reuse the recovered material to produce 100% new crates, with no involvement of third parties. In this case, the amount of the secondary granulates that substitutes the virgin material (substitution ratio) with the same quality is very high (i.e., 97% for IFCO, 2017). However, the scientific literature (i.e. Abejón et al. (2020) and Tua et al. (2019)) has commonly used an average value of substitution ratio of 70%, as published by Albrecht et al. (2013), who assumed an open-loop recycling. Moreover, all closed-loop recycling systems have fully food grade application, as reported by EFSA, since they use closed and controlled chains.
In 2018, the European Union established the goal that “by 2030, all plastics packaging placed on the EU market is either reusable or can be recycled in a cost-effective manner”. In this regard, it is worth mentioning that the current RCPs pooling systems are already in line with this strategy by manufacturing reusable and recyclable crates, and really advanced to meet this goal.