While Switzerland’s citizens avidly collect their used PET beverage bottles, a clear decline in segregation quality has come about of late, resulting in an increased quantity of foreign substances in the collections. This is what Swiss association PET-Recycling Schweiz (PRS, Zurich; www.petrecycling.ch) is complaining about in a statement it has just published. Contamination by foreign substances is endangering this “highly ecological bottle loop” and making PET recycling more expensive, the criticism continues. The sorting technology employed cannot solve this problem alone and the entire population is called upon to act.

Since PET recyclate requires a purity level of 99.96% at the end of the recycling process, PRS is calling for stringent requirements on the cleanliness and purity of PET beverage-bottle collections in Switzerland – something that can only be achieved if the bottles are collected separately. And, as they further set out, the Swiss Federal Food Safety Office (FSVOV) is even demanding that only PET beverage bottles from unmixed collections be permitted to enter the bottle loop, to the exclusion of other PET bottles. Other plastic bottles are recycled by the Migros and Coop supermarket chains in Switzerland, employing a collection and recycling process that is separate from PET.

If contaminants like shampoo and cleaning agent residues are introduced into the PET collection, then, according to PRS, even the two new sorting facilities in Frauenfeld and Grandson, which rank amongst the most modern in the world, cannot subsequently do anything about it. In extreme cases, the operating speed of the sorting plants has to be reduced by up to 25% and more handsorting must be performed in order to remove the impurities. Disposing of the contaminants also entails high costs, placing a burden on the entire recycling system.