Why do plastic bottles have curves

Separate plastic bottle collection redefined

Studies show that it makes more economic and ecological sense to collect PET and plastic bottles separately than to collect all plastic waste in a mixed collection. In addition to the PET beverage bottle collection, Migros has therefore been consistently separating further plastic bottles since 2013. Their uniform type of plastic is ideal for the closed product cycle. Now a Migros industrial company is testing the production of cleaning agent packaging.

Andreas Renggli

The recycling walls of all branches have been designed uniformly so that when they are returned it is clear at first glance which bottles are going where. Source: Migros

Last year, in addition to the 9,400 tons of PET bottles, Migros also collected 2,800 tons of milk and other plastic bottles and recycled them. That's a new record. Since the company introduced the expanded plastic bottle collection across Switzerland in 2013, the number of plastic bottles returned by customers has increased by a total of 150 percent. And even in 2016 the increase compared to the previous year was 350 tons (+14 percent).

For Heidi Oswald, Environment Project Manager, the steady increase is a sign that the separate plastic bottle collection is establishing itself: “With the introduction of the plastic bottle collection, we have redesigned the recycling walls in all branches so that it is clear at first glance when they are returned which bottles go where. In addition, we have sensitized our customers to the expanded collection of plastic bottles directly at the collection points and via our communication channels. These measures have been well received. "

Current comparison of collection systems

The topic of plastics recycling is a controversial topic in the professional world and in cities and municipalities: How much collection and recycling is ecologically and economically sensible? Should every plastic film and every plastic tray such as meat packaging or yoghurt pots be collected together with plastic bottles? The "KuRVe" study published in July by the UMTEC Institute for Environmental and Process Engineering at the University of Applied Sciences Rapperswil (HSR) and Carbotech AG examined the environmental benefits and costs of collection and recycling systems for plastics from households in Switzerland. The clients were eight cantons, various associations and the Federal Office for the Environment (FOEN).

Poor environmental benefit from mixed plastic collections

The study shows that the mixed collection of plastic waste has only a relatively small ecological benefit, but at the same time causes high costs, namely around 750 francs per ton. According to the study, the costs of disposing in garbage bags are significantly lower at around CHF 250 per ton. The additional environmental benefit achieved is also very low because it is by no means possible to recycle everything that is collected in a mixed manner. The difficulty here is to cleanly separate the numerous different types of plastic from one another. A considerable part ends up in the incineration at the end and the promise of comprehensive recycling is usually not kept by mixed collections.

Problem of foreign matter in separate collections

Mixed collection solutions for plastics that are offered in some municipalities or by private companies also have a negative impact on the quality of the existing separate collections and thus reduce their ecological benefits: In view of these mixed collections, consumers sometimes no longer understand what can be disposed of and where therefore throw other plastic packaging into the purely separate collections of the retail trade.

Using the example of the separate PET beverage bottle collection, this means: One percent more foreign matter leads to additional annual costs of 300,000 francs for the collection system. In summary, it can be said that it makes more economic and ecological sense to only collect plastic bottles that can be recycled into new products due to the uniform type of plastic. The aim is to be able to feed as much high-quality recyclate as possible back into industrial production.

Recycled polyethylene for packaging of detergents

Migros is currently investing in a high-quality form of recycling - in closing the material cycle. She is developing solutions for using recycled polyethylene (PE) from her separate plastic bottle collection in her own industrial operations. At Mifa, the largest Swiss detergent and cleaning agent manufacturer, tests are currently being carried out on the use of recycled polyethylene in cleaning agent bottles. One challenge, for example, is the smell of the recycled material. It is difficult to extract the strong smells of lactic acid in milk bottles and of perfume in detergent and cleaning agent bottles so that the material can be used again in an odorless form for packaging.

(Andreas Renggli is a communications consultant and editor at polarstern.ch)


Short report of the “KuRVe” study at carbotech.ch and for the Migros Recycling Guide: