As part of our Innosuisse project, we are investigating the feasibility of a closed-loop system for polypropylene (PP) food packaging in Switzerland. Together with our research partners, KATZ (Plastics Training and Technology Center) and the Institute of Technology Management at the University of St. Gallen (HSG-ITEM) and our industrial partners BASF Schweiz AG, Coop Genossenschaft, Emmi Schweiz AG, Greiner Packaging AG, InnoPlastics AG, Migros Industrie AG, Silac AG and Säntis Packaging AG, we are developing a value chain for post-consumer PP that meets the high food safety requirements. Closing the loop would not only conserve valuable resources and support net-zero targets, but also strengthen the resilience of the Swiss economy.
The project builds on the findings of the successful Innovation Booster project "Circular Economy for Polypropylene (CE4PP)", in which we investigated the theoretical recyclability of PP packaging.
Simulation of the PP cycle in Switzerland
As part of the project, we simulated and experimentally tested the first Swiss value chain for secondary PP for food packaging. The main focus was on practical implementation, food conformity, the quality of the recyclate and the ecological and economic viability.
Our implementation partners are represented along the entire value chain, we at realcycle bring the partners together and ensure successful and sustainable implementation with our expertise in sustainable circular economy, ecological assessment and project management.
Figure: Overview of the work steps of the project "Development of closed loops for food contact rPP".
Implementation and process optimization
To simulate the PP cycle, the collected materials were subjected to extensive technical tests at KATZ. A central process step is the sorting of the post-consumer material, as packaging must be separated according to its area of use (food/non-food applications) and its production technology (injection molding or thermoforming) in order to obtain a high-quality recyclate. Sorting by application is carried out using artificial intelligence and near-infrared spectroscopy. However, there is still no established technology for sorting by production technique. In the project, high levels of purity were achieved through manual sorting; however, further technological advances are required for industrial scaling. After sorting, the packaging was shredded into flakes, washed and deinked. The post-consumer PP was then processed into regranulate.
By March 2025, the recycled material obtained for the first demo packaging made from recycled PP will be tested in industrial processes at Greiner Packaging AG, Säntis Packaging AG and Silac AG. Emmi Schweiz AG will then examine the filling and sealing behavior of the recycled packaging. At the same time, initial migration tests will be carried out to determine where we stand with the recyclate in terms of food conformity.
In addition to the technical investigations, HSG-ITEM carried out a systemic economic analysis to assess the economic viability of the project. These findings support the companies in sustainably integrating the newly acquired knowledge into their processes. We at realcycle also examine the ecological impact as part of a comprehensive life cycle assessment.
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