As part of the ISPT CP-50-02 project: Towards improved circularity of polyolefin-based packaging, the sortability of 16 packaging materials to create 2 dummy benchmark streams selected by Amcor, Unilever and Nestlé was determined.
The first benchmark dummy stream represents the composition of nowadays (2020) household plastic packaging waste, whereas the second benchmark dummy stream represents the 2025 household plastic packaging waste. All the studied packaging material were made of multilayer material and the majority of the packaging was flexible material.
Results show that in general, all the packaging ends up in the 2D stream, only two materials (M- 769 and M -762) will not end up in the 2D stream. A detailed optical sorter analysis of all packaging was performed. The major results are:
- Multilayer material that contains a metallic (Al) layer cannot be sorted well due to reflection by the metallic layer as only the external in the polyolefin (PO) stream.
- If the packaging has several non-PO layers above the PO layer, the probability that the optical sorter can classify as the major plastic content and sorted as PO is reduced.
- Multilayer material containing PVC is sorted as PO, which might not be acceptable.
Assuming a sorting towards flexible PO streams, dummy streams for pyrolysis experiments should be prepared the following way:
- Shred the packaging materials separately (both clean and contaminated), leading to 32 batches of material.
- Compose four (4) mixtures based on the individual packaging material composition and use these in lab scale pyrolysis:
- 2020 dummy, clean
- 2020 dummy, contaminated
- 2025 dummy, clean
- 2025 dummy, contaminated