“What we urgently need is a less emotionally charged debate on plastics”

Plastics are at present the subject of intensive public controversy. But what exactly are the current prospects for the future sustainability of PET & Co.? Some illuminating answers to this question are provided in an interview with three of Krones’ plastics experts: Dr. Thomas Friedlaender, Head of Plants PET Recycling, Jochen Forsthövel, Product Manager Plastics Technology, and Simon Fischer from the Plastics Application Technology Department.

An increasingly controversial attitude towards plastic packaging can be observed among the public. What is your take on this?

Jochen Forsthövel: A vast majority of the criticism being voiced relates to two aspects: firstly to the littering of our environment, and here especially to marine litter, and secondly to excessive resource utilisation, i.e. our throw-away mentality. Both problems do not relate to plastics alone, though they are overly manifest with this material at the moment, so that plastics are currently assuming a kind of scapegoat function. And here it’s not the material itself that poses the actual problem, but its often excessively thoughtless use.

According to the EU’s plastics strategy, the aim is for PET bottles to contain at least 25 per cent of recycled material by 2025. How realistic is this target?

Simon Fischer: As far as processing is concerned, this is most definitely realistic. Rather more difficulties, as things stand at present, are being encountered on the supply side, i.e. assuring a stable flow of adequate-quality input material. You see, it’s not just bottles that are produced from recyclates, but also films and fibres, for example. This is why there is already some competition between the various user industries as to who can purchase the material needed at an appropriate level of quality.

There would in fact be enough material for recycling available if only it were to be collected …

Thomas Friedlaender: Yes, sure, this is where it all starts. But with the material collected, what I’m holding in my hand is a bottle that someone else has thrown away – so nothing gained at this point.

Jochen Forsthövel: What I have actually gained is that every single bottle collected is prevented from ending up unsupervised in the natural environment. It doesn’t matter whether I manage to recycle it into a new bottle, whether I use it for producing polyester fibres or whether it is made into trays – or (if very severely soiled) passed to the refuse incineration plant. All of these packages that are collected no longer contribute to littering our environment.

Simon Fischer: And it’s here that the politicians, too, are called upon to put in place appropriate collection systems. In Germany, things have really moved forward since the introduction of the bottle deposit. Through the reverse vending machines, around 97 per cent of the empty PET bottles are being returned to the cycle of re-usable materials. These systems will presumptively be adopted in other countries as well.

This would in fact create attractive opportunities for companies wishing to enter the recycling business, wouldn’t it?

Simon Fischer: You’re right, because not only do collection systems boost the material flow, they also result in the material being available in better starting quality.

Thomas Friedlaender: On the other hand, deposit schemes are also always viewed with a rather critical eye, because they tie up large amounts of money in the closed cycle. This is not the only way to do things, as can be impressively observed in Switzerland: there, the citizens dispose of their PET bottles voluntarily (meaning without the pressure of a deposit) at around 50,000 collection points in schools, local council facilities, offices and sports grounds. The return ratio achieved is just as high as in Europe’s most successful deposit nations. This is doubtless influenced by the national character, too; after all, the Swiss are generally regarded as extremely disciplined. The main reason, however, is in my opinion the very skilful marketing involved, which repeatedly motivates consumers to bring back their bottles after drinking the contents. So it’s definitely possible to put in place a smoothly functioning closed-cycle system without mandatory deposits.

Switzerland is also a role model as far as recovery is concerned, since the PET beverage bottles collected are returned to the recycling circuit and are made into new bottles – from both an ecological and economic viewpoint, this bottle-to-bottle approach is ideal.

Krones is also adopting the bottle-to-bottle approach with its MetaPure lines. What is the target group for this technology: beverage bottlers or rather the recovery sector?

Thomas Friedlaender: Definitely both. Our customers include both traditional-type recycling firms and bottlers who want to handle their material production in-house. These are typically clients who also blow-mould their own preforms. For them, recycling is then the logical completion of their value added chain. Our first MetaPure client Akij Food & Beverage from Bangladesh is basically self-sufficient. The only thing they were lacking back then was an in-house PET production capability. By installing our recycling line, they finally achieved a completely autonomous set-up.

From what demand level is a MetaPure line financially viable?

Thomas Friedlaender: Particularly when I’m self-sufficient as a bottler, all I really need is the output from two blow-moulding machines – then it’s already worthwhile doing your own recycling. What’s more, if I don’t sell the recyclate obtained as a raw material, but process it directly to create a customised product, I gain an additional advantage: I can eliminate pelletisation, which is the most energy-intensive step of the process. Our client rPlanet Earth in the USA is doing precisely this: the recyclate is processed directly on site to make preforms, for example. This means the pellets are eliminated as an intermediate step, since the flakes go directly into the preform mould.

In what output ranges do Krones’ MetaPure lines operate?

Thomas Friedlaender: When we entered the field of recycling technology eleven years ago, the lines we conceived were still relatively small – simply because we were primarily targeting the self-sufficient companies. A line of this kind then needs about 5,000 tons of input material per annum. Meanwhile, though, we’ve long since begun to build lines for large recyclers as well. These then recover 40,000 to 50,000 tons a year – almost 10 times as much. Generally, our experience is that the lines clients want us to build are becoming progressively larger. The best example here is a customer who has been highly successful in Japan for many years now with our technology: his first two MetaPure lines were rated towards the lower end of our output range. Lines Three and Four were then in the middle of this continuum. It wouldn’t surprise me if the next lines were to be in the upper output range. You really notice how the trend is moving progressively upwards.

Jochen Forsthövel: In Japan, the starting conditions are in any case ideal for bottle-to-bottle recycling, because the PET beverage bottles there are all transparent.

Thomas Friedlaender: That’s right: the beverage world in the Japanese supermarkets is garishly colourful, sure. But differentiation there is effected solely through the sleeves, while the bottles themselves are clear – and can thus be 100 per cent recycled.

Recycling PET is one thing, its re-usability is another. How well suited for stretch blow-moulding is recycled PET?

Simon Fischer: On Krones’ stretch blow-moulding machines, recycled material can be handled in just the same way as new merchandise – irrespective of the order of magnitude involved. And many of our lines have been handling it for a long time. The most important stipulation here is a supply of homogeneous, consistently high-quality input material – but that applies equally to new merchandise. The larger the scale on which recycling is operated, the easier it will be to produce uniform quality.

Jochen Forsthövel: Some of the properties exhibited by recycled PET are even beneficial to its processability, chief among them the somewhat darker colour created by multiple recycling: this ensures that the material accepts the thermal energy better in the heat-up process, thus reducing both the heating time before stretch blow-moulding and the energy consumption.

What do things look like quite generally for the amount of energy that’s required for PET bottle production?

Jochen Forsthövel: Most of the energy hidden in a package is contained in the material itself. But there is, of course, a certain amount of leverage in the machine technology for designing everything to be eco-friendlier. At Krones, we have our enviro programme for this purpose, under whose aegis Plastics Technology also has its machines certified. In terms of energy consumption, we can confidently assert that with the Contiform series we have the best-in-class solution in-house. And we still have a long way to go on this journey, so we are working continually on becoming even better.

Another way to reduce resource consumption is the lightweighting of PET bottles. Have the limits of the possible already been reached there?

Jochen Forsthövel: This is rather like asking whether we have reached the limits of what’s humanly possible in the 100-metre sprint. Yes, there are doubtless ranges that will always be closed to us, but I don’t believe we will no longer be able to change the status quo. I think that the bottles will become a bit lighter in the future, too, but certainly not in the sizeable steps we’ve achieved in the past ten years. There are markets in which lightweight bottles have not yet gained real acceptance, because they run counter to consumers’ quality preferences. But there, too, sooner or later, for reasons of cost alone, demand for lightweighting will emerge. And so it’s a good thing that we at Krones have the requisite skills in-house for developing together with our customers bottles that are light in weight and economical in material consumption while still being easy to use and to process.

Besides the recycling of PET, its replacement by alternative material is being discussed with increasing frequency – above all by bio-plastics. What’s your take on this?

Jochen Forsthövel: When it comes to bio-plastics, you have to draw a general distinction between two different types of plastic: biodegradable plastics on the one hand, and bio-based plastics on the other. PET can – at least in some cases – also be produced as a bio-based substance, meaning from renewable raw materials instead of oil. Even if the source of the material is different: its chemical properties are identical to those of conventional PET. So bio-based PET can be processed just as well in existing lines as its oil-based equivalents.

In the case of biodegradable plastics, by contrast, entirely different materials are usually involved. So far I know of no biodegradable plastic that possesses a profile of properties comparable to PET and would thus be suitable on a large scale for packaging beverages.

Simon Fischer: There are currently two bio-plastics that are at the forefront of discussions when it comes to superseding PET as beverage packaging. One of them is PEF, which is polyethylene furanoate: it can be produced as a bio-based material, but it’s not biodegradable. And the other is the PHAs, meaning polyhydroxyalkanoates. Though these are genuinely biodegradable, about at the level of hardwood types, they are at present still very much more expensive than our standard packaging plastics, and (a weightier consideration) so far it has not proved possible to produce beverage packages from them on a large scale. So whether this is a good, practicable option for the future cannot as yet be estimated with the present state of our knowledge.

Jochen Forsthövel: It’s also important in this context to remember that biodegradation usually takes place in conditions exhibiting a certain degree of humidity and temperature. When packaging damp products like beverages, the use of appropriate bio-plastics is thus in general significantly more difficult than producing a carrier bag. Biodegradable beverage bottles would be the premier league, so to speak, and present definite technical difficulties.

Thomas Friedlaender: Polylactic acid, or PLA for short, is a bio-based plastic that is perfectly well suited for still beverages with a relatively short shelf-life. Over the product’s entire life-cycle, though, PLA also has a disadvantage: because the material is not as thermally stable as PET, it should not be allowed to get into the PET flow during recycling, since otherwise it would impair the latter’s quality. This is quite generally the major challenge entailed by a comprehensive closed-cycle economy: the material flows have to be precisely matched to each other. So if you’re going to introduce new material in sizeable quantities, you have to ask yourself what the long-term effect will be on the system as a whole.

That means that from a recycling viewpoint it would be more sensible to stick with one material than to continually expand the spectrum in a search for alternatives?

Jochen Forsthövel: Absolutely correct. This is also precisely the thinking behind the EU Directive that’s currently on everyone’s lips and that is set to be incorporated in national legislation within the next few years. When the binding stipulation comes into force that PET bottles have to contain 25 per cent recyclate, then that means straight away the end of the road for all other materials for which there are no recycling flows. Whether this was intended by the EU or not: for recycling it is definitely advantageous if you only have a few different types of plastic, but these are being used in large quantities. Because then the sorting losses decrease, and the material purity involved is improved.

Thomas Friedlaender: We have to state quite clearly, though: bio-based PET is not a problem in terms of recycling. As Jochen Forsthövel has already pointed out: no matter what source of raw material I’m using – when the end-product is a PET, then in terms of processing and recycling it will have precisely the same characteristics as oil-based PET. It’s quite different with biodegradable plastics or substitute materials. From a recycling viewpoint, to start with, these constitute a contamination of the PET flow. Not only that: the label “biodegradable” suggests that the materials concerned will, as it were, conveniently lose themselves in the natural environment. But let’s assume that all the plastic ending up in the sea would in some form or other degrade into nutritional hydrocarbons: what specific consequences would ensue for the ecosystem is unforeseeable. So when it comes to the possibilities involved in degradation, we have to ask ourselves the general question: what ultimately happens with the degraded materials?

Jochen Forsthövel: The idea’s already been put forward of admixing degradability additives to various mass plastics, so as to reduce the waste problem. But this is something that needs to be viewed very critically, since most additives of this kind merely cause a fragmentation of the material concerned. After two years, I may then perhaps see no traces of the material in the natural environment. In actual fact, though, it has only disintegrated into minuscule particles, and no one can say with certainty how these are going to affect the ecosystem in the long term.

PET is in terms of market share the most important packaging plastic in the beverage industry – but it’s by a long way not the only one. What do things look like for the recyclability of other materials, used for lids and secondary packages, for example?

Thomas Friedlaender: In Krones Recycling Technology, we are totally committed to a holistic approach. We insist on recycling the entire plastic package, meaning the non-PET plastics as well. Here, the same applies as what we said previously about PET: here, too, it would be ideal if the industrial sector were in future to manage with fewer specialty plastics, so as to put a bit of a restriction on the quantity of materials that are mutually incompatible. Above all, it’s important to think beyond the first recycling process: if I get a mixed plastic as the end-product of recycling, then this can perhaps be used again once, but that’s as far as it goes. Our goal is closed cycles – so recycling should be performed with all due care and attention.

Krones’ MetaPure lines are based on a mechanical recycling process. What’s your take on the future of chemical recycling?

Jochen Forsthövel: Chemical recycling is an obvious option for materials that can no longer be sorted or for other reasons can no longer be mechanically processed – principally for mixed plastics.

Is this currently an issue of interest for Krones?

Thomas Friedlaender: No, because with chemical recycling, as the name implies, the basic product created is a chemical one. This is a long way away from us and our sector. We shall stick with mechanical recycling and preserve the polymer.

Simon Fischer: Which is definitely sensible when you look at the sheer amount of energy and processing history that’s stored in plastic. There’s a lot of work being done at present on chemical recycling, but I would also suspect that it’s primarily of interest for difficult-to-recycle fractions – such as difficult-to-separate composite materials or dyed fibres.

Thomas Friedlaender: Chemical recycling does entail a major disadvantage: all the outlay originally expended on polymerisation is lost again. Thus chemical recycling is a useful supplementary technology, but it should certainly not play a leading role.

What would you like to see in regard to plastics for the future?

Jochen Forsthövel: I would like to see a recovery system in which all plastics used can be appropriately recycled. Either in a closed loop or in some other way. And in which the effects of the materials that leave the ordered system – whether due to unfortunate accidents or for other reasons – cause as little damage as possible.

Thomas Friedlaender: I would like to see more emphasis on what functionalities plastic packages can have: above all, that they protect foods and beverages from spoilage, that they reduce the transportation weight, and that they make drinking water available in regions where the supply is problematic. Regrettably, these advantages are far too often ignored in the ongoing debate. I personally would also welcome more binding regulations on recycling quotas and similar arrangements – even if this may not win me any new friends.

Simon Fischer: I thoroughly concur. What we urgently need is a less emotionally charged debate on plastics. The demonisation of plastics neither gets us any further nor does it do justice to the properties of this material that’s so important for our society. Ultimately, all of us – consumers, manufacturers and politicians alike – are equally called upon to deal responsibly with the material.