A recent peer-reviewed study conducted by the Polymer Engineering Department of the University of Bayreuth provides new, robust evidence on the recyclability of expanded polystyrene (EPS) bead foams. Published in Polymer Engineering & Science, the research evaluates EPS recycling performance under conditions explicitly aligned with the EU Packaging and Packaging Waste Regulation (PPWR).
By simulating ten consecutive mechanical recycling cycles with a constant recycled content of 35 by weight (wt%), the study offers one of the most detailed assessments to date of how EPS behaves when repeatedly reprocessed. Its conclusions bring important clarity to ongoing discussions on recycled content targets, material performance and the practical implementation of circular economy requirements for EPS packaging.
In this context, EUMEPS has interviewed Dr Ingo Bellin, Head of Process Development and Quality Control Styrenics, BASF SE, on his views about the study’s main findings. Ingo is a long-standing polymer chemistry expert with 20 years of industry experience and was one of the experts involved in setting up the tender for the study.
Ingo, from your perspective, why is this study an important contribution to the discussion on recycled content requirements under the PPWR?
It is important to know that, for a polymer, EPS achieves quite an impressive recycling rate of roughly 40% already today. The recycling predominantly takes place via converting EPS packaging waste into construction products, which have a lifetime of several decades. Thus, the recycled products are typically not recycled again.
With the introduction of the 35% recycled content quota for protective packaging products, our industry will have to recycle the EPS packaging waste into packaging products with lifetimes of roughly one year only. This means, from 2030 onwards, recyclates will face the challenge to maintain quality levels with each recycling cycle that will take place roughly every year.
Now, the great news is that the study was able to show that in the investigated repeated mechanical recycling steps (10 cycles in total), the EPS typically used in protection packaging showed only limited degradation of mechanical properties. We knew already that EPS can be efficiently mechanically recycled, but the study provides further evidence of how well the EPS industry is positioned to fulfil the PPWR quotas.
What do the study’s conclusions tell us about the long-term reliability of EPS when it is mechanically recycled and blended with virgin material?
As explained, the study demonstrates that EPS polymer is, in principle, very well positioned to fulfil the challenging PPWR targets. However, in real recycling scenarios, waste management will also have a significant impact on the number of maximum possible recycling cycles and, consequently, how much research is required to counteract quality deterioration during recycling steps. Therefore, sorting and mechanical recycling technologies need to be further developed to ensure that our entire industry will be able to achieve the challenging recycling targets.
Our industry can be optimistic to overcome the challenges, since the study also provides valuable insights for future improvements of EPS recycling, such as that EPS recycling performance is not constrained by recycling itself, but by specific processing steps that simply require careful process control.
And what conclusions doesn’t the study allow us to draw?
The study focused on the mechanical recycling of EPS. While I am very happy that the results support strong developments in this area, it would be premature to ignore the role of chemical recycling technologies. I believe chemical recycling (predominantly depolymerisation and pyrolysis) will also be an essential technology for EPS packaging recycling going forward.
Firstly, in the short-term, fulfilling recycled content targets for food contact packaging relies on chemical recycling as it delivers virgin-like products, which allow for meeting the strict quality requirements.
Secondly, as the recycled content quotas will rise significantly in 2040 (65%) and require much greater amounts of recyclates, more and more recycling of low-quality or dirty EPS waste streams will likely be necessary to close the recyclate gap.
And thirdly, chemical recycling technologies will also play a role in “resetting” the qualities of recycled materials back to virgin materials, both in terms of mechanical properties and regarding chemical contaminants.
Which practical lessons should industry and policymakers take from this study on recycling and what are your thoughts more broadly speaking?
The study proves scientifically that EPS packaging can be mechanically recycled with minor deterioration of mechanical properties over 10 recycling cycles. The material is therefore very well positioned to meet the challenging recycled content quotas for protective packaging.
Based on the excellent study results, I am also confident that the already impressive recycling rate for EPS packaging in the EU will further increase in the coming years. Policy makers should consider this when developing EPR schemes or promoting bans of certain packaging formats based on common allegations such as low-recyclability, which obviously is not true for EPS.
Nevertheless, additional EPS packaging waste streams will need to be exploited to increase overall recycling rates, because available recyclates will, in the short-term, simply be redirected to the packaging sector (instead of the construction sector as today). Here, policy makers can support, e.g. by incentivising the use of recycled products in the construction sector.
While mechanical recycling is crucial for recycling of EPS, the long-term PPWR targets will require very high recyclate demands, which will unlikely be covered by mechanical recycling alone. Thus, development and investment in chemical recycling or other technologies allowing the recycling of low-quality waste streams is also needed, such as solvent-based recycling. Policy makers need to develop a regulatory framework that enables companies to make these investment decisions.
Unfortunately, only slow progress was made on regulatory acceptance of chemical recycling and relevant issues and thus has been a significant factor in slowing down progress in this important field of recycling.
Ingo Bellin’s interview places the study’s results in a clear industrial and regulatory perspective. While the research confirms that EPS can be mechanically recycled over multiple cycles with limited and predictable changes in performance, it also highlights that future PPWR targets will require continued improvements across the value chain.
As he underlines, maintaining quality over time will depend not only on the material itself, but also on effective sorting, recycling technologies and careful control of key processing steps. The study therefore provides a solid scientific basis to support informed policy choices and further investment in EPS recycling solutions.