Recyclates: What is possible in medical technology?

Recyclates for medical technology? „The pressure on medical technology manufacturers to use recyclates in their products is increasing from the EU as well as from clinics and care facilities“, says Dr Julian Lotz, Managing Director of the young Darmstadt-based compounder Biovox GmbH. „Most hospitals will be obliged to report on sustainability in the coming years in accordance with the Corporate Sustainability Reporting Directive (CSRD) reporting of sustainability . This also includes CO2 corporate emissions. To reduce these, they will pass on the pressure to act sustainably to their suppliers.“

The CSRD also applies to the medical technology manufacturers themselves. „With our plastic parts, we are very quickly on the radar within the Group when it comes to the sustainability targets because we are one of the main contributors to Scope 3 emissions“, confirmed Dr Martin Halter, Head of the Consumables division. Martin Halter, Head of Consumables Manufacturing Science & Technology at Roche Diagnostics, at a medical technology event at machine manufacturer Engel in spring. „The journey must therefore clearly be towards the processing of recyclates.“ However, the Swiss company will not start the recyclate journey with its diagnostic products he said. Halter: „Packaging is a good first step, as it is the least critical 

Arno Pfaff, Vice President Business Development & Strategy at Barnes Moulding Solutions, notes that companies in the plastics industry have been preparing strategically and technically for the processing of recyclates for years: „In recent years, implementation has been difficult because recyclates were not available on the market in sufficiently large quantities available. At present, their prices are still an obstacle compared to new goods.“

Medical technology: No chance for recyclates in direct contact with patients

Add to this: „For all products with direct patient contact plastics with recyclate content are very difficult to use. As a rule, this also applies to primary packaging of medicines“, Pfaff clarifies. Paulo Cavacas, Business Development Manager Healthcare at plastics manufacturer Borealis, is particularly dismissive of mechanically recycled materials that are available on the market: „The waste streams from mechanical recycling are not always controlled. Therefore, they cannot be used for medical applications due to the risk of contamination or impairment of product quality and therefore patient safety . Only in a few exceptional cases can mechanically recycled materials be used in the healthcare sector.“

Lucas Pianegonda, Managing Director of Gradical, a Swiss consulting company for plastics in medical technology, cites as examples casing for ventilators or mechanical components on wheelchairs. „The quality of materials that come from mechanical recycling has improved significantly in recent years: there are practically odourless recyclates, as well as transparent ones. So it is no longer only possible to produce flowerpots and park benches with them," says Pianegonda. „It is also possible to manufacture products on the injection moulding machine using the sandwich process which are made of virgin material on the outside and recycled material on the inside.Pfaff still sees great opportunities for transport materials in diagnostics and drug delivery, as well as for pharmaceutical secondary packaging, which therefore does not come into contact with medicines.

The opportunities of mechanical recycling for medical technology

Pianegonda and Pfaff have observed that companies are currently looking for ways to incorporate mechanically produced post-industrial recyclates (PIR) plastics production into their production processes– not least to save money. This means that parts produced during injection moulding production are separated according to type, crushed cleaned and melted on site . „I see great potential for this type of mechanical recycling on site in the factory, for example in the case of intermediate plastic products that are produced for the manufacture of the end product,„ says Pfaff. „The material is still largely sold to recycling companies today. A few times this granulate can be processed on the injection moulding machine without any problems, but in continuous processes they require sophisticated control technology due to the large fluctuations in the material.“

Just like mechanical recycling, solvent-based recycling is a material recycling process. This makes it possible to selectively separate polymers in mixed plastic waste. However, this requires the appropriate chemical process engineering, which separates liquid and solid components from plastics in a multi-stage process. „For example, colour can be removed or multilayer films can be separated“, says Pianegonda. „The advantage is that the quality of the recyclate is better than with mechanical recycling– and the environmental impact is lower than with chemical recycling. The disadvantage is that there are hardly any companies that use this process on an industrial scale. And I have not yet seen any application of these recyclates in medical technology.“ The Merseburg-based company APK and Purecycle from the USA are among the few players in this field. They extract pure polyolefins from packaging waste for reuse in packaging.

Depolymerisation: Another route to recyclates for medical technology

In addition to the mechanical recycling of plastics, there is also the chemical recycling of plastics. And here, too, there is depolymerisation a process that is still in its infancy, but according to Biovox boss Lotz „in principle is even suitable for human products“. During depolymerisation, plastics are enzymatically, catalytically or with water vapour broken down into their components .Depoly, a spin-off of the Swiss Federal Institute of Technology Lausanne (EPFL), uses the highly energy-efficient process for PET, which takes place at room temperature.

The only chemical recycling process that is technically mature is currently pyrolysis. This is used to extract pyrolysis oil from plastic waste at very high temperatures. Plastics manufacturers feed this oil into their composite production at the beginning of the value chain. „It is a transformative technology solution that gives a new life to polyolefin-based post-consumer waste,“ explains Cavacas, Borealis. „This allows us to obtain materials in new product quality and create high safety– and performance qualities&ät for demanding applications.“

Chemical recyclates: designed for use in medical technology

Chemically recycled grades would be suitable for new polymers, but the range of chemical recyclates

on the market is currently very limited. As soon as they are available, Borealis intends to offer its so-called Borcycle-C plastics – where C stands for chemical recycling  for use in medical technology . „This will be done üvia mass balancing“, says Cavacas.

„The chemical recycling is the only one that currently fulfils the requirements of the VDI guideline Medical Grade Plastics from 2017“, says Pianegonda. The VDI guideline is currently being revised, but it will not contain any explicit specifications regarding recyclates either. Instead, the same requirements apply to them as to virgin material. This also applies to the Medical Device Regulation (MDR), which generally describes the requirements that risk management for materials must fulfil.

In the race for the first chemically recycled medical-grade plastics that are not mass-balanced Biovox wants to be one step ahead. In the foreseeable future, according to CEO Lotz, it is primarily polyester that will be available. A disposal company will collect contaminated products from clinics and then decontaminate them. A partner will then recycle these products via depolymerisation for Biovox.

High CO2 footprint for pyrolysis recyclates

With chemical recycling by means of pyrolysis the same product properties as with new material are achieved,„the recyclates can therefore be used without revalidation or recertification of the production processes,„ says Biovox CEO Lotz. But it is not just the product properties that are the same as those of virgin materials - the carbon footprint is also the same. „That's actually contradictory. Recyclates are used to protect the environment, but ultimately the recycling process with the worst environmental balance wins, because the CO2 footprint of pyrolysis is significantly greater than with the other processes," Pianegonda complains.

If you have to use more energy for recycling than is produced by incineration in residual waste-to-energy plants, then you have to say clearly: burn the plastic waste.

Article from "medizin & technik" from 21/09/2023