Creating cycles for flexible packaging (films)

This pilot project, part of the realCYCLE project made possible by the Migros Pioneer Fund, was designed and implemented in collaboration with stakeholders in the plastics value chain. The overarching theme of realCYCLE was to understand and organize the entire value chain of plastic packaging as a cycle. The systemic requirements and framework conditions for scalability were examined and concrete possibilities were identified that would enable a comprehensive and sustainable plastic recycling economy in Switzerland.

Focus and Core Questions

The focus is on polyethylene (PE) or polyolefin (PO) films.

Although recycling is continuing to increase, mainly of PE films, there are still a number of challenges and hurdles that need to be overcome in order for the economy to succeed in closing the loop in a sustainable manner. This is particularly true for post-consumer waste, which is difficult to collect and recycle. This is due to high geographical dispersion, higher organic contamination, extensive printing on packaging, moisture and UV barriers, and multi-layer packaging.
Increasingly complex packaging coming onto the market is a major challenge for this material stream. For example, multi-layer packaging (e.g., laminates or composites) usually contains 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 of application and value of the recyclate. In addition, the combination of LLDPE/LDPE with other materials (typically paper or aluminum) and other polymers makes recycling difficult or impossible. Poorly designed packaging that is not easy to empty and is therefore often heavily contaminated with organic matter also has a negative impact on the technical performance and visual appearance of the recyclate. Packaging made of multiple materials can be discarded during the sorting phase (and is usually incinerated) or, if sorted correctly, has a negative impact on the input material intended for the recycling process and the quality of the output. Paper, aluminum, or other polymers that are welded to LDPE cannot be separated during sorting or the pre-treatment steps of the recycling process and are therefore extruded together with LLDPE/LDPE.
Constant fluctuations in the quality of the recyclate de facto alter its performance and increase the processing costs of recycling. This consequently affects the price and fluctuations in quality as well as the quantities available on the market. LDPE is already used in closed-loop systems today, which means that it can be returned to the same or similar applications (e.g., shrink wrap, carrier bags). Nevertheless, significant quantities of rLDPE are used in niche applications such as street furniture (benches) and various shelves and drainage systems, which place less demanding requirements on the properties of the recycled material. It is estimated that around 50% of the rLDPE/LLDPE currently placed on the market could be used in film applications if there were sufficient demand for it.

The project therefore focused on the following points:

• • What is the available volume potential in Switzerland to enable flexible packaging to be actually recyclable according to the current state of the art, taking into account current aspects of «Design for Recycling»?

• • Is mechanical recycling possible and practical (film type, processing technology, ecological benefit)? Are there ecologically and economically viable alternative recycling technologies to mechanical recycling?

• • How can efficient collection logistics for flexible packaging from households (post-consumer waste) be established?

Objective of the pilot project

Flexible plastic packaging is one of the most frequently used materials in a wide variety of products, from food to numerous non-food applications. Plastic film has an ideal strength-to-weight ratio, making it a popular packaging material. In order to minimize material consumption, increasingly thinner films are in demand and are being produced. However, in order to ensure that the strength of the packaging and the protection of the contents are fully guaranteed, specific barriers and/or other protective layers are required in many applications (especially in the food sector). In contrast to mono-material films, the material recycling of such composite films is technically much more difficult and makes recycling economically uninteresting and ecologically questionable.

What was worked on

The project primarily involved compiling basic information and data so that the relevant facts and necessary conditions for practical implementation could be established:

• • Quantity flows and potential (types of plastic, quantities, system boundaries) taking into account the main criteria of "design for recycling" for flexible packaging:
    At the time of the project, no usable data was available for the Swiss market to make a realistic statement about the existing quantity flows and recycling potential. The data available in the EU also did not allow for extrapolation to the Swiss market. Therefore, data collection was not carried out. Based on figures from 2011, it was assumed that annual film consumption in Switzerland amounts to around 50,000-60,000 tons (main plastics: PP, PE(L)LD, and PEHD).

• • Collection logistics (point of return, volume vs. weight, selective vs. mixed, infrastructure, logistics capacities):
    As part of the"Collection 2025"project team (a project of Drescheibe Kreislaufwirtschaft, starting in January 2022), REDILO/realCYCLE has been researching and working on this topic in collaboration with stakeholders in the value chain.

• • Infrastructure and technology (availability in Switzerland/EU, trends, mechanical processes, sorting):
    Information on this topic has been compiled and its relevance and opportunities for Switzerland assessed (critical success factors, obstacles).
    – Available infrastructure and technologies
    – Capacities, sorting depths, and qualities
    – Processing and recycling processes
    – State of the art (?)
    – Recyclate qualities, secondary markets (potential, availability)
    – Innovations (e.g., HolyGrail 2.0, R-Cycle)