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 on packaging design and circular economy, supporting them in finding a sustainable strategy for cheese packaging films, known as tubular bag films. For this purpose, tubular bag films made of two different material mixtures were examined and compared 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 called «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.
Assessment and optimization potential of recyclability
When assessing recyclability, both theoretical and actual recyclability can be considered. Theoretical recyclability refers only to compliance with technical guidelines. It alone does not bring any ecological benefit. Only high-quality recycling and the reuse of the recyclate, i.e. the actual recyclability, create this benefit. The actual recyclability refers to a market area, as it depends on the conditions existing in the given system, such as collection, sorting and recycling plants.
The recyclability was assessed according to the criteria of the Recyclability Rate Assessments of RecyClassTM. The final recyclability rate is composed of the following criteria:
- Basic suitability for material recovery,
- 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, Authorisation 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 environmental impacts
We determined the environmental impacts using the ecological scarcity method. This includes various criteria such as climate impact, damage to human health and the ecosystem, and resource requirements. The environmental impacts are summarized in a single key figure. This indicator is expressed in environmental impact points [UBP]. In addition, the CO2 footprint was determined 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 showed 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 the optimized OPP-PP film was recommended. Based on this, Emmi has developed the corresponding concepts with its suppliers.
In principle, it is particularly important that the collection and material recovery of plastics in Switzerland is established comprehensively and uniformly. Only then can the film actually be recycled.