Focus and key questions
The focus is on polyethylene (PE) and polyolefin (PO) films.
Although recycling of mainly PE films continues to increase, there are still a number of challenges and hurdles that need to be overcome in order for the economy to succeed with sustainable closed loop recycling. This is especially true for post-consumer waste, which is difficult to collect and recycle due to high geographic dispersion, higher organic contaminants, extensive printing on packaging, moisture and UV barriers, and multi-layer packaging that makes recycling difficult.
Increasingly complex packaging entering the marketplace is a major challenge of this material stream. For example, multilayer packaging (e.g., laminates or composites) typically contain barriers that are incompatible with the chemical properties of LLDPE/LDPE and have a negative impact on the color and purity of the final recyclate during the recycling process. This leads to a reduction in the scope and value of the recyclate. Furthermore, the combination of LLDPE/LDPE with other materials (typically paper or aluminum) and polymers makes recycling difficult or impossible. Poorly designed packaging that cannot be easily emptied and is therefore often heavily contaminated with organic matter also has a negative impact on the technical performance and visual aspect of the recyclate. Packaging made of multiple materials can be discarded during the sorting phase (and is usually incinerated) or, if sorted correctly, negatively affects the input material intended for the recycling process and the quality of the output. Paper, aluminum, or other polymers welded to LDPE cannot be separated during sorting or pretreatment steps of the recycling process and consequently are extruded together with LLDPE/LDPE.
Constant quality variations in the properties of the recyclate de facto change its performance and increase the processing costs of recycling. This consequently affects the price and the fluctuations in the qualities as well as the quantities available on the market. LDPE is already used today in closed loop systems, which means that it can be recycled into the same or similar applications (e.g.: shrink films, carrier bags). Nevertheless, significant amounts of rLDPE are used in niche applications such as street furniture (benches) and in various shelving and drainage systems that have less stringent requirements on the properties of the recycled material. It is estimated that about 50% of the rLDPE/LLDPE put on the market today could be used in film applications if there were sufficient demand for it.
The following points are in focus:
- How large is the volume potential available in Switzerland to enable actual recyclability of flexible packaging according to the current state of the art, taking into account current aspects of "design for recycling"?
- Is mechanical recycling possible and reasonable (type of film, processing technology, ecological benefit)? Are there ecologically and economically sensible alternative recycling technologies to mechanical recycling?
- How can efficient collection logistics for flexible packaging from households (post-consumer waste) be established?
Aim of the pilot project
Flexible plastic packaging is one of the most widely used materials of various products, ranging from food to numerous non-food applications. A plastic film has an ideal strength-to-weight ratio, which makes it a popular packaging material. In order to minimize material consumption, thinner and thinner films are being demanded and manufactured. However, to ensure that the strength of the packaging and the protection of the contents can still be fully guaranteed, specific barriers and/or other protective layers are required for many applications (especially in the food sector). In contrast to monomaterial films, the recycling of such composite films is considerably more difficult from a technical point of view and makes recycling economically unattractive as well as ecologically questionable.
What we are currently working on
In the current project phase, mainly basic information and data are being compiled in order to create the relevant facts and necessary conditions for implementation in practice:
- Volume flows and potentials (plastic types, volumes, system limits) taking into account the main criteria of the "Design for Recycling" for flexible packaging:
Unfortunately, no usable data are currently available for the Swiss market in order to be able to make a real statement on the existing volume flows and recycling potentials. The data situation in the EU also does not allow extrapolation to the Swiss market. For this reason, no current data collection is being carried out at the moment. Based on figures from 2011, it is still assumed that annual film consumption in Switzerland is around 50,000-60,000 tons (main plastics: PP, PE(L)LD and PEHD).
- Collection logistics (point of return, aspect volume vs. weight, selective vs. mixed, infrastructure, capacities logistics):
As part of the project team "Collection 2025" (project of the Drescheibe Kreislaufwirtschaft, start January 2022) REDILO/realCYCLE will explore and work on this topic, in cooperation with actors of the value chain.
- Infrastructure and technology (availability CH/EU, trends, mechanical processes, sorting):
Information is currently being compiled in this topic area and the relevance and opportunities for Switzerland are being assessed (critical success factors, hurdles).
- Available infrastructure and technologies
- Capacities, sorting depths and qualities
- Processing and recycling processes
- State of the art (?)
- Recyclate qualities, secondary markets (potentials, availability)
- Innovations (e.g. HolyGrail 2.0, R-Cycle)
Pilot Project Partner
- UAS East (Buchs Campus)
- MIGROS Industry
- Nestlé Suisse SA
- O. Kleiner AG
- POST CH AG
- Semadeni Plastic Group / kunststoff.swiss
- Wipf AG