The recycling of multilayer films is said to work - even on an industrial scale.

 

This is reported by the project's cooperation partners BASF, Krones, Südpack and Tomra. The beginning of 2021 was the project start . Because of the different materials, recycling of multylayer film is considered difficult. However, it has been shown that PET/PE multilayer packaging can also be separated and recycled on an industrial scale under certain conditions, the project participants report. In the first industrial trial in a pilot plant at Krones in Flensburg, they succeeded in separating 69 percent of the PET/PE components completely and 12 percent partially. One advantage of the approach is said to be that the multilayer packaging can be recycled in the existing infrastructure. In the project, the separation of the packaging layers worked after packaging manufacturer Südpack processed the PET/PE trays with a "debonding adhesive" from BASF, is said. "With our water-based Epotal adhesives, we have already achieved very good results in the laboratory when separating multilayer packaging," explains Kresimir Cule, Commercial Marketing Industrial Adhesives at BASF. "We consider the fact that we were able to completely separate 69 percent of the packaging right from the first industrial trial a great success. This can certainly be further expanded by optimizing our debonding adhesive system." Südpack managing partner Carolin Grimbacher adds, "Thanks to our special know-how in water-based lamination, we are able to produce multilayer films that can be separated by basic hot washing." The recyclable PET/PE trays were then separated from non-recyclable trays in a Tomra sorting facility using autosort technology. "We were able to do this with the help of our NIR technology. This allows us to identify PET multilayer trays that contain the BASF adhesive, so we can subsequently pull them out of the waste stream and send them for recycling," says David Rüßmann, manager of special projects at Tomra. Krones, a supplier of recycling systems, has been involved in the project since September 2022 and has made its pilot plant available for this purpose. There, he says, trials were conducted using a hot-washing process commonly used for PET recycling to separate PET and PE from the composite films on an industrial scale. In the process, the materials were successfully separated, according to the company. "In our line, we have proven that delamination of multilayer films works, and the separation of the films can be further increased by optimizing individual process parameters and also, for example, the particle size of the flakes," explains Thore Lucks, Head of Technology Recycling Solutions at Krones. The project will be continued, he adds, and the recycling rate of plastics is to be increased even further by adjusting various process parameters in the recycling process and by further developing the laminating adhesive used. The quality of the recyclate is also to be improved. "The aim is to use the PET again for the production of food packaging. The PE fraction is also to be used as a raw material for new packaging in the non-food sector," emphasize the project partners.

 
Further information: www.basf.com, www.krones.com, www.suedpack.com, www.tomra.com
 

Sources:

• Plasticker (May 5, 2023)
• Photo: © BASF