You have been a lecturer at IKV for more than 25 years. How does the task you will now be tackling differ from your previous activity at IKV?
Prof. Grefenstein: In addition to my lecturing activities, the new task also involves driving research further forward in the field of recycling. In the plastics segment, we are at present subjected to unparalleled challenges, for example through the new EU packaging directive. It is therefore imperative that we recycle more, and also that we recycle at a higher level. IKV has already addressed this topic in a number of joint research projects. Nevertheless, I still see considerable potential in the field of 'advanced mechanical recycling' to be able to recycle material to match the quality of virgin material, or at least close to it. To be quite honest, many present-day recyclates are still nowhere near meeting the requirement profiles for more demanding applications such as food and pharmaceutical packaging. And who, if not Europe's biggest plastics institute, should study such new recycling processes?
The plastics circular economy is a highly diversified topic. Some studies focus on avoiding microplastic in the environment, and others investigate global material flows. Then there are experts who deal with the legal regulations. You just mentioned 'advanced mechanical recycling' as a segment with which you are intensively occupied. Apart from that, are there any other topics on which your work is currently focused?
Prof. Grefenstein: Apart from the further development of recycling technologies, I strongly support the idea that all representatives of the plastics segment should speak with one voice. As the Chairman of EuPC - the European association of plastics converters based in Brussels - I can see that the plastics industry is finding it difficult to do precisely this. The recycling, converting and raw material producing associations have, in the past, sometimes sent out very diverging messages. Although we have slowly come together, there are still some different viewpoints, for example with regard to new standards that aim to define what is recyclable. It is clear that a company which produces a potentially non-recyclable material will sometimes have different interests than those that the plastics industry as a whole should aim for. And the task of a neutral institute here should be to determine on a scientific basis what then really hinders recycling, even if it may then be an uncomfortable message for many industrial companies.
Do you also see it as a task for IKV to play a mediating role between the interest groups?
Prof. Grefenstein: Definitely. There are a few people in our industry who were still saying a few years ago that the new recycling technologies would solve everything, and that we should simply carry on as we have been doing up until now. In the meantime, the majority of companies have recognised that not only do we need better recycling technologies, we also need ambitious "design-for-recycling". It is thus now largely undisputed that we should work with monomaterial concepts, in other words, one main material and as few "contaminating" subsidiary materials as possible. Manufacturers of these latter products, which make recycling more difficult, may perhaps see things a little differently, but we need to be absolutely honest here.
Is the industry suffering from cost pressure? It is certainly possible to increase the quality, but then the recycling and the use of the recyclate become all the more expensive - or not?
Prof. Grefenstein: That is at present precisely the problem. If we really want to have high-quality recyclate materials at acceptable cost, then we need both: better recycling technologies and consistent design-for-recycling.
In the past, there were often times in which the circular economy topic gained importance, but then interest in it faded again. What makes you optimistic that the present awareness for the circular economy - which manifests itself not only in research but also throughout the industry, in the trade press and in general public discussion - is more sustainable and will lead to real, effective changes?
Prof. Grefenstein: We have reason to be optimistic because the majority of people want a regulation that is uniform throughout the EU, in other words, binding legislation and not a non-binding directive as was the case, for example, with the single-use plastics directive. What would be the biggest problem for the industry and for an effective circular economy today would be a patchwork of measures across Europe. If we succeed in creating truly mandatory, uniform standards in Europe - because physics in Germany is no different than it is in Belgium - then this could also become an export success. Countries such as India, Indonesia and China are watching us very closely in this respect. What I am also optimistic about is that the plastics industry has been under such great pressure for many years that things have started moving that would not have been conceivable before. On the other hand, we need to continue moving consistently along this path. And other materials such as paper composites must also go along with this. In the case of the design standards for paper recycling, for example, far too much is still being accepted. Paper in supermarkets that protects the contents from oxygen and water vapour still contain plastics, which is why the claim to be "plastic-free" is scientifically untenable. The consequence of this is that, if I throw away a piece of paper packaging in the countryside, we then have microplastic in the countryside.
If you had the possibility to formulate a new legal regulation and to implement it immediately, in which direction would you go?
Prof. Grefenstein: In the packaging directive, there are some passages in which plastic is discriminated against in comparison to other materials. To name one example: Binding quotas for the use of recyclate exist in the directive only for plastics. Here, I would wish for greater neutrality on the part of the legislator as regards the materials. Apart from that, the packaging directive does not define what is recyclable, but makes a reference to European standards. What I would like is that these European standards are not only ambitious but are also realistic enough for them to be practicable for the industry. This is what the struggle is about at present, and I wish every member of the committees the patience and wisdom to get things sorted out.
At the moment, recyclate is expensive, so that if we decide to act in the spirit of the circular economy, we have to pay something on top if we want to maintain the standard at the same time. What needs to change in order to be able to make money from it?
Prof. Grefenstein: I know some recycling companies that are already working very profitably, but I also know of other recycling companies that have, for various reasons, got into difficulties - especially in phases in which the price of virgin plastics declines but the price of recyclate remains more or less at the same level as the production costs. However, companies that are now already working with advanced recycling methods can earn good money despite a difficult overall environment. That makes me optimistic that recycling will also be an interesting business model in the future - not only for the recyclers themselves, but also for the recycling machine manufacturers, which are also mostly central European companies.
If the circular economy is the declared aim, can we then leave it to the development of market mechanisms, or do we need control through politics? After all, virgin material is in most cases cheaper than recyclate.
Prof. Grefenstein: That is not absolutely correct, because recyclates as such are not more expensive than virgin material. Especially mechanically produced recyclate is generally cheaper than virgin material, but much inferior as far as the properties are concerned - they have specks etc. However, the closer the recyclate comes to the level of the virgin material, the more expensive it becomes. And then we very quickly reach the point where it costs more than virgin material. And now let us talk about chemical recycling, through which I can obtain exactly the same properties as with virgin material. That is significantly more expensive simply because it is a high-energy process. With "advanced mechanical recycling", on the other hand, I see the potential to produce recyclate at the same price level as virgin material, so that there is no price difference for converters. And yes, that must be the aim .
At IKV, the topic of circular economy is always linked closely to that of digitalisation. Can we say that these two areas of research actually fire up each other, in other words that digitalisation supplies new methods and thus lifts the circular economy to a new level? Perhaps two things come together here that can really bring about a leap in innovation that would not have been conceivable 20 years ago?
Prof. Grefenstein: Yes, digitalisation will definitely play a role. With today's modern sorting technologies, it is possible to easily separate different types of plastic through a simple spectroscopic process. What it is not possible, however, is to separate food packaging from non-food packaging and thus to separate food grades or potential food grades from non-food grades, because it is not possible to recognise this physically from the material. Modern imaging processing technologies can, however, easily recognise whether the product is, for example, a yoghurt beaker or a paint bucket. That is an example that will definitely come, and all experts are basically agreed on this. Others, in turn, go so far as to provide every product with a digital product passport, which states precisely what it is based on. Whether we will ever go that far and even need to go that far is for me perhaps rather questionable, because we would then sometimes also have to disclose the patented know-how of companies in the value chain. How that can be done without betraying company secrets remains a challenge.
To what extent would you support the theory that an adequate number of good approaches exist in research to bring about a functional circular economy but that there is something lacking when it comes to its implementation in practice?
Prof. Grefenstein: In my opinion, the subject of plastics recycling has so far not been tackled enough by many research institutes. Although there are institutes that, for example, deal with topics such as food legislation, in other words how recyclate can be made food-compatible, they study the topic, so to speak, from the perspective of approval for use. Yet research on the subject of recycling equipment, recycling machines, new recycling concepts etc. is at present hardly being carried out at all in the university segment, except, of course, in the initial stages at IKV. And this is precisely what the task is for IKV, which, with its tradition of plastics processing machinery, it will tackle even more intensively than before. The sometimes very new developments and processes are being driven mainly by small-sized start-ups. Here, I consider it to be an important function for IKV to carry out studies on a scientifically neutral basis and to evaluate what the new processes can do and what they can't.
When you look back, are there for you any special milestones in the development of plastics recycling?
Prof. Grefenstein: In the mid-nineties, in my time as head of the extrusion department, we were involved with research projects for the Federal Environment Agency on the subject of both mechanical recycling and chemical recycling. Chemical recycling was initiated at that time as degradative extrusion, also on the initiative of Professor Menges. One of my colleagues was then carrying out research in this field and we recognised that, for example with chemical recycling, a wild mixture of various plastics has much lower yields than for example a pure mixture of polyolefins. Findings such as this are already decades old. But then, as we all know, chemical recycling did not manage to establish itself with the green dot, because there were already contracts with the mechanical recyclers. When I then started in 1996 at BASF, we had a large pilot plant for chemical recycling in the technical service department. BASF was at that time willing to invest, but we did not receive the promise of the necessary volume from the green dot because the contracts had already been concluded with mechanical recycling. For many years I had to tell my students that chemical recycling had not been able to establish itself. In the lectures, I only mentioned it for the sake of completeness. Five years ago, I then learned from chemical recycling companies that they were using precisely the extruder process that we at IKV had researched at that time. Many things, as is evident here, simply take time.
In the meantime, the opinion prevails anyway that all recycling processes - both mechanical and chemical - should be used in parallel.
Prof. Grefenstein: Exactly. And there are constantly new processes and new ideas coming along. I am convinced that, if we set the people challenging targets with the packaging directive, then the creativity will certainly also be there to solve the problems. That brings me to a final point I would like to mention. It will also certainly become one of my tasks along the line - that IKV has a problem recruiting a sufficient number of new students.
You are talking about declining numbers of students in mechanical engineering and in plastics technology?
Prof. Grefenstein: Yes. It is important here that we convey to the students doing the Bachelor course that plastics are not "evil", but that they offer plenty of big opportunities.
As an employee of a company that handles several different materials, I can only say that, as far as life cycle assessments are concerned, plastic has no reason to hide behind other materials. Quite simply, this is because, compared with other materials, I can, by using plastic, pack something with the lowest packaging weight per kilogram of contents. This means that, if the politicians seriously want to reduce the amount of packaging being used, it will not work without plastic, only with plastic - but in a more intelligent way than at present.
Yes, the eyes of the general public are directed one-sidedly at the problems caused by plastics when they get into the eco-systems. On the other hand, the potential of plastics is not adequately perceived - precisely with regard to the circular economy.
Prof. Grefenstein: That is exactly the problem. Let me give you an example: The company Constantia, for which I still work, has several production sites in India. India is the first country where we introduced our monomaterial concept in which demanding high-barrier and ultra-high-barrier packaging also consists primarily of the material polyethylene. We have observed that the waste pickers in India collect only what is of value, for example polyester bottles or milk cartons made of polyethylene. Formerly, we also had polyethylene bags such as this in Europe before they were replaced by TetraPaks. At that time, they were unable to establish themselves because the plastics were not yet good enough and the packs often burst. However, with today's metallocene polyethylene, we do not have this problem any more. It is used in India and the waste pickers even collect it. This led us to the conclusion that, "if we want to get the stuff off the beaches, we must make it worth something, in other words it must be a monomaterial." Nor must it be processable with quite such advanced mechanical recycling methods, because a recycling extruder of this kind standing in a newly industrialised country can look a little bit different from the modern machines here in Europe.
That is certainly a graphic example of how the circular economy can be brought to life through the use of monomaterials. But getting back to the problem of the shortage of new recruits at IKV: I do not believe that students are so naïve that they think plastic is "evil", particularly when they - as here in Aachen - come from the field of mechanical engineering and can only decide later during their studies to opt for the specialist subject of plastics. Nevertheless, we find that it is often the application that decides whether interest is aroused for plastics or not: Our events on the subject of medical technology, for example, are full to bursting point because, in this context, no-one casts doubt on whether the use of plastic is correct and appropriate. Things are very different with packaging.
Prof. Grefenstein: I can only emphasise that every young person who has technical talent and cares about the environment would be well advised to get into the plastics segment and especially the packaging segment, because we can only master the enormous challenges with the creativity of young people. For this, we need more upcoming students to solve the current difficult tasks. I also believe that the vast majority of the companies now pursue a really serious sustainability strategy. In the medium term, it is precisely the companies that only superficially carry out a bit of greenwashing that will have the biggest problem finding new recruits in the future.
What appeals to you particularly about your new task at IKV?
Prof. Grefenstein: Well, to be quite honest, when the idea was born during a talk with Christian Hopmann that I should spend a little less time in the industry in order to invest more time here at IKV, it appealed to me very much. This was also because I personally owe a lot to the Institute for my training. I have never regretted studying here and can only recommend it to young people.
Does that also mean you will now be working more scientifically again?
Prof. Grefenstein: Yes, definitely, and I am looking forward to it.