Emmi AG is one of the leading Swiss companies for high-quality dairy products. As part of the Swiss Resource Efficiency Network (Reffnet.ch), we advised Emmi in the areas of packaging design and circular economy and supported them in finding a sustainable strategy for packaging films for cheese, so-called tubular bag films. To this end, tubular bag films made from two different material blends were examined and compared with each other in order to develop recommendations for improvements. One of the two films, which consisted of polyethylene terephthalate (PET) and polyethylene (PE) (hereinafter referred to as "PET-PE film"), was in use at the time of the analysis. The other film consisted of two layers of differently treated polypropylene (PP). One layer, so-called oriented PP (OPP), was specially prepared and stretched to be resistant and stable. The second layer was conventional PP. In the following, this film is referred to as "OPP-PP film". In addition, the second film was optimized with regard to its recyclability (hereinafter referred to as "optimized OPP-PP film"). In the analysis of the two film types, the aspects of recyclability and environmental impact were compared.
Evaluation and optimization potential of recyclability
When assessing recyclability, both theoretical and actual recyclability can be considered. Theoretical recyclability only refers to compliance with the technical guidelines. It alone does not provide any ecological benefit. Only the high-quality recycling and reuse of the recyclate, i.e. the actual recyclability, creates this benefit. Actual recyclability relates to a specific market area, as it depends on the conditions available in the given system, such as collection and sorting and recycling facilities.
The recyclability was assessed according to the criteria of the Recyclability Rate Assessment of RecyClassTM criteria. The final recyclability rate is made up of the following criteria:
- Basic suitability for material recycling,
- Existence of recycling streams, i.e. local collection and corresponding sorting and recycling infrastructure in the country,
- proportion of recyclable plastics,
- Sortability of the packaging materials,
- Compliance with the Design for Recycling guidelines,
- Easy to Empty Index and
- Compliance with REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)
Da in der Schweiz im Jahr 2021 keine flächendeckende Sammel-, Sortier- und Recyclinginfrastruktur vorhanden war, wurden die Folien als nicht rezyklierbar eingestuft. Zudem enthielten die Laminataufbauten der Verpackungsfolien einen für das Recycling noch nicht freigegebenen Klebstoffanteil. Wenn sowohl die technische Infrastruktur als auch die Zertifizierung des Klebstoffanteils vorhanden gewesen wären, hätte die PET-PE-Folie immer noch mit 0% Recyclingfähigkeit abgeschnitten. Grund dafür war der Laminataufbau PET-PE, der zur Disqualifikation führte. Besser schnitt die OPP-PP-Folie mit 18 bzw. die optimierte Folie mit 52 % ab. Optimierungsmöglichkeiten bestanden in der Reduktion des Ethylen-Vinylalkohol-Copolymer (EVOH) -Anteils auf ein recyclingverträgliches Mass (< 5 %) und in der Minimierung der bedruckten Fläche.
Consideration of the environmental impact
We determined the environmental impact using the ecological scarcity method. This comprises various criteria such as climate impact, damage to human health and the ecosystem, and resource requirements. The environmental impacts are summarized in a single indicator. This indicator is expressed in environmental impact points [UBP]. In addition, the CO2-footprint was calculated using the IPCC 2013 method.
The OPP-PP film also performed better than the PET-PE film in terms of environmental and climate impact. The optimized OPP-PP film had a comparable environmental and climate impact to the non-optimized OPP-PP film. In order to achieve the lowest possible environmental and climate impact in combination with high recyclability, the increased use of optimized OPP-PP film was therefore recommended. Based on this, Emmi has developed the corresponding concepts with its suppliers.
It is fundamentally important that the collection and recycling of plastics in Switzerland is set up in a comprehensive and uniform manner. Only then can the film actually be recycled.