Money doesn’t grow on trees, as they say, but often it lies right in front of us: every carelessly discarded PET bottle is a loss of valuable resources. That said, however, collecting these PET bottles and reintroducing them into the material cycle is well worth the effort. Purifed polyethylene terephthalate (PET) is the perfect starter material for high-quality products such as bottles, film or fibres.
Collect and recycle
Despite the rising proportion of regenerative resources in polymer material, it is still predominantly made from crude oil. Thermal recovery of PET after its life cycle is a tried-and-tested approach, but it releases emissions that are harmful to the environment – as is the case with conventional combustion processes. This method also wastes valuable material that could be put to much better use by the industry. In contrast to other plastics, which are copolymers, PET is a monopolymer with high-quality properties and is, as such, almost unique in its perfect suitability for recycling.
The German population’s passion for collecting PET bottles was triggered by the introduction of a deposit return system, which led to a highly successful return rate of up to 98 %, according to a publication by Forum PET. About one third of the returned bottles is reused to make new PET bottles, another third is used for industrial film and about one fifth goes into the production of textile fibres. The use and deployment of recycled PET products obviously inspires new ideas among companies, namely to reuse PET bottles for the production of school bags, jumpers and trainers, as well as film for furniture and car parts.
Preparing the ground
The thriving business with disposable PET bottles is supported by the introduction of central collection hubs, where manually introduced bottles are crushed and compressed by a compactor. At the recycling plant, the material is sorted and cleansed, then shredded into fingernail-sized pieces, which can be plasticised and turned into pellets – the starter material for the production of new, high-quality plastic products. Other industrially endorsed collection systems are also in place for recycling plastic window profiles and used agricultural film.
Scientists are already working on the biotechnological optimisation of the plastics recycling process. They are conducting tests with bacteria and enzymes that digest and break down polymers into their basic constituents. This interdisciplinary approach holds potential for new jobs, which is likely to be put into practice. Plastics are materials with added value, which, when collected and segregated, can easily be reintroduced into the material cycle. Efficient recycling will become increasingly important – and will be a major issue at K 2019.