In the interview, Prof. Dr.-Ing. Achim Grefenstein talks about the goals he associates with his new position as Scientific Director at the IKV.
© IKVYou have been a lecturer at IKV for over 25 years. How does the new task that awaits you now differ from your previous work at IKV?
Grefenstein: In addition to teaching, the new role is also about advancing research in the field of recycling even further. As a plastics industry, we are currently facing unprecedented challenges, such as the new EU Packaging Directive. We must therefore recycle more in any case and also recycle to a higher quality. IKV has already addressed this topic in several joint research projects. Nevertheless, I still see great potential in the area of advanced mechanical recycling to recycle material back to virgin material level or at least close to virgin material level. To be honest, today’s recyclates are still far too far removed from most requirement profiles in demanding applications such as food or pharmaceutical packaging. And who, if not Europe’s largest plastics institute, should investigate such new recycling processes?
The circular plastics economy is a wide-ranging topic. Some focus on avoiding microplastics in the environment, while others investigate global material flows. Then there are experts who deal with the legal requirements. You have just mentioned advanced mechanical recycling as an area that you are working on intensively. Are there any other topics that you focus on in your work?
Grefenstein: In addition to the further development of recycling technologies, I am committed to ensuring that representatives of the plastics industry speak with one voice. As Chairman of EuPC, the European Association of Plastics Converters in Brussels, I have noticed that the plastics industry is struggling with precisely this. The recycler, converter and raw material producer associations have sent out very different messages in the past. We have slowly come together, but there are still some differences of opinion, for example with regard to the new standards that are to define what is recyclable: What is recyclable? It is clear that a company that manufactures a potentially non-recyclable material is sometimes pursuing different interests than the plastics industry as a whole should be aiming for. And the task of a neutral institute here should be to determine on a scientific basis what really interferes with recycling, even if it is an uncomfortable message for some industrial companies.
Do you also see it as IKV’s task to mediate between the various interest groups?
Grefenstein: Also to communicate, of course. There are a few people in our industry who were still saying a few years ago: The new recycling technologies solve everything, we’ll just carry on as before. The majority of companies have now recognised that, in addition to better recycling technologies, we also need sophisticated design-for-recycling. This means that it is now largely undisputed that we need mono-material concepts, i.e. one main material and as few “impurities” as possible. The producers of these materials, who make recycling more difficult, may see things a little differently, but you have to be honest.
Is the industry suffering from cost pressure? Quality can certainly be improved, but recycling and the use of recyclates becomes all the more expensive – doesn’t it?
Grefenstein: That’s exactly the problem at the moment. If we really want to have high-quality recyclates at reasonable costs, we need both: better recycling technologies and consistent design-for-recycling.
In the past, there have always been periods in which the topic of the circular economy has gained in importance. But even then, interest in them flattened out again. What makes you optimistic that the current attention to the circular economy, which is manifested not only in research but also industry-wide, in the trade press and in the general public debate, is more sustainable and will lead to real, effective change?
Grefenstein: We have reason to be optimistic because the majority want uniform EU regulation, i.e. binding legislation and not a non-binding directive, as was the case with the Single Use Plastics Directive, for example. The thing that would disrupt industry and an effective circular economy the most today would be a European patchwork quilt. If we manage to create truly binding, uniform standards in Europe – because physics is not different in Germany and Belgium – then this could also become an export hit. Countries such as India, Indonesia and China are watching us very closely in this respect. I am also optimistic that the plastics industry has been under so much pressure for years that things have changed that were previously unthinkable. However, we must continue along this path consistently. And other materials such as paper composites also have to keep up. Too much is still accepted when it comes to design standards for paper recycling, for example. Papers in supermarkets that protect the contents against oxygen and water vapor always contain plastics, which is why the claim “plastic-free” is scientifically untenable. The consequence of this is that if I throw paper packaging into the forest, then I have microplastics in the forest.
If you had the opportunity to formulate a new legal requirement and implement it immediately, what direction would it take?
Grefenstein: There are several passages in the Packaging Directive that discriminate against plastic in comparison to other materials. To give an example: There are only binding quotas for the use of recycled materials for plastics. I would like to see more material neutrality from the legislator here. Furthermore, the Packaging Directive will not define what is recyclable, but will refer to European standards. I would like these European standards to be both ambitious and realistic enough to be achievable for the industry. This is what is currently being discussed, and I wish those who sit on the committees much wisdom.
At the moment, recyclates are expensive, which means that if you want to act in the spirit of the circular economy, you pay extra if you want to maintain the standard at the same time. What needs to change so that you can earn money with it?
Grefenstein: I know recycling companies that are already working very profitably today. However, I also know recycling companies that have got into difficulties for various reasons – especially in phases when the price of virgin plastic is falling but the recyclate has more or less the same production costs. However, those who are already working with advanced recycling methods can earn good money despite a difficult overall environment. This makes me optimistic that recycling will continue to be an interesting business model in the future – not only for the recyclers themselves, but also for the recycling machine manufacturers, most of which are also Central European companies.
If the circular economy is the declared goal, can development be left to market mechanisms or does it need to be controlled by politicians? After all, virgin material is usually cheaper than recycled material.
Grefenstein: That’s not absolutely true, because recycled materials are not inherently more expensive than virgin material. Mechanically produced recyclates in particular are generally cheaper than virgin material, but their properties are significantly worse, they have specks, etc. The closer recyclates are to virgin material, the more expensive they become. However, the closer recycled materials come to the level of virgin material, the more expensive they become. And then we quickly get to the point where they are more expensive than new goods. And let’s talk about chemical recycling, which allows me to achieve exactly the same properties as virgin material. This is significantly more expensive, simply because it is a high-energy process. In the case of advanced mechanical recycling, on the other hand, I see the potential to produce recyclates at virgin material price levels so that it is equal in price for the converters. And yes, that must be the goal.
At IKV, the topic of the circular economy is always closely linked to the topic of digitalization. Is it the case that these two areas of research are currently fuelling each other, i.e. that digitalization is providing new methods and thus taking the circular economy to a new level? Perhaps two things are coming together that could actually bring about a leap in innovation that would have been unthinkable 20 years ago?
Grefenstein: Yes, digitalisation will definitely play a role. With today’s modern sorting technologies, different types of plastic can be easily separated from each other using simple spectroscopy. What you can’t do, however, is separate food packaging from non-food packaging and thus separate food grades or potential food grades from non-food grades, because you can’t physically see it in the material. However, modern image processing technologies can very well recognise whether it is a yoghurt pot or a bucket of paint, for example. This is an example of what will definitely happen, as all experts agree. Others even go so far as to include a digital product passport with every product, detailing exactly what it is made of. Whether we will ever get that far and whether we have to get that far is still a bit of a question for me. Because then we would also have to give up some of the protected know-how of companies in the value chain. How this is done without revealing company secrets is still a challenge.
To what extent would you support the thesis that there are enough good approaches in research to realise a functional circular economy, but that there is a lack of practical implementation?
Grefenstein: In my opinion, the topic of plastics recycling has not yet been sufficiently addressed by many research institutes. There are institutes that deal with topics such as food law, for example, i.e. how to make recyclates suitable for food. The topic is examined from the release perspective, so to speak. However, research into recycling aggregates, recycling machines and new recycling concepts is currently hardly taking place in the university sector, apart from initial approaches at IKV. And this is precisely the task that IKV, with its tradition of plastics processing machinery, will take up even more intensively. The developments and processes, some of which are still very new, are largely driven by smaller start-ups. I consider it an essential task of the IKV to investigate and evaluate on a scientifically neutral basis what the new processes can and cannot achieve.
When you look back, do you see any particular milestones in the development of plastics recycling?
Grefenstein: In the mid-1990s, during my time as head of the extrusion department, we were involved in research work for the Federal Environment Agency on both mechanical recycling and chemical recycling, which was also launched at the initiative of Professor Menges as so-called degradative extrusion. One of my colleagues was doing research in this field at the time, and we realized that, for example, in chemical recycling, a wild mixture of different plastics has significantly lower yields than a pure polyolefin mixture, for example. Such findings are already decades old. However, as we all know, chemical recycling did not prevail with the Green Dot, as there were already contracts with mechanical recyclers. When I started at BASF in 1996, we had a large pilot plant for chemical recycling in our application technology department. BASF was already willing to invest at that time, but we were unable to obtain the necessary volume commitment from the Green Dot because the contracts with mechanical recycling had already been concluded. For years I had to tell my students: Chemical recycling has not caught on. I only mentioned it in the lecture for the sake of completeness. Five years ago, I learned from chemical recycling companies that they were using exactly the same extruder process that we were researching at IKV at the time. Some things, as we can see here, simply take time.
In any case, the prevailing opinion is that all recycling processes – both mechanical and chemical – should be used in parallel.
Grefenstein: Exactly. And new processes and new ideas are constantly being added. I am convinced that if you set people challenging goals with the packaging directive, then there will certainly be the creativity to solve the problems. This brings me to one last point, which will certainly be one of my tasks somewhere down the line: Because the IKV also has problems with young talent.
Are you referring to the declining numbers of students in mechanical engineering and plastics technology?
Grefenstein: Yes. It’s important to show people during their bachelor’s degree that plastic is not “bad”, but offers great opportunities.
As someone who works for a company that works with several materials, I can only say that: In terms of life cycle assessments, plastic doesn’t have to hide behind other materials, if only because it allows me to pack with the lowest packaging weight per kilogram of contents compared to other materials. This means that if politicians are serious about reducing packaging, then it cannot be done without plastic, but only with plastic – but more intelligently than before.
Yes, the public’s focus is one-sidedly on the problems that plastics cause when they enter ecosystems. On the other hand, too little attention is paid to the potential of plastics – especially with regard to the circular economy.
Grefenstein: That’s exactly the issue. One example: Constantia, the company I continue to work for, has several locations in India. India is the first country where we have introduced our mono-material concept, where even demanding high-barrier and ultra-high-barrier packaging is mainly made of polyethylene. We have found that the waste pickers there only collect what has value, e.g. polyester bottles or polyethylene milk cartons. Such polyethylene bags also used to exist in Europe before they were replaced by Tetrapacks. They didn’t catch on back then because the plastics weren’t good enough and the bags often burst. But with today’s metallocene polyethylene, we no longer have these problems. It is used in India and the waste pickers even collect it. That led us to the conclusion: “Hey, if we want to get this stuff off the beach, we have to give it a value, so it has to become mono-material.” And it must also be possible to process it using less advanced mechanical recycling methods, because a recycling extruder located in an emerging country may look a little different to the modern machines here in Europe.
A clear example of how the circular economy can be set in motion through the use of monomaterials. But let me come back to the problem of young talent at IKV: I don’t think that students are naïve enough to think that plastics are “bad”, especially when students – like here in Aachen – come from the field of mechanical engineering and can only decide on this specialisation later in their studies. Nevertheless, we find that it is often the application that determines whether or not an interest in plastics is aroused: our events on medical technology, for example, are packed because in this context there is no question as to whether the use of plastics is correct and appropriate. Packaging is a different story.
Grefenstein: I can only emphasize this: Every young person who has a technical talent and who cares about the environment is well advised to go into the plastics industry and especially into the packaging industry. Because we will only be able to overcome the huge challenges with the creativity of young people. To do this, we need more young talent to solve the current exciting tasks. I also believe that the vast majority of companies are now pursuing a really serious sustainability strategy. You have to convey that to young people. In the medium term, those companies that only do a little greenwashing superficially will have a major problem recruiting new talent.
What excites you most about your new role at IKV?
Grefenstein: To be honest, when the idea came up in conversation with Christian Hopmann that I should cut back a bit in industry in order to invest more time here at IKV, it really appealed to me. Also because I personally owe a lot to the institute as a training center. I have never regretted studying here and can only recommend it to young people.
Does this also mean that you are now working more scientifically again?
Grefenstein: Yes, absolutely, and I’m looking forward to it.