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Interview with MKV Managing Director Rainer Zies on avoiding pellet losses

Rainer Zies is Managing Director of MKV GmbH Kunststoffgranulate, a medium-sized family-run company in the German Bundesland Hessia. It is specialised in the recycling and compounding of waste plastics from technical applications. As a member of the board of the TecPart association for technical plastic products, Rainer Zies plays an active role for the industry and represents the industry’s interests in public and in politics and also on national and European committees. Apart from that, Rainer Zies is a member of the Technical Committee of BKV GmbH and of the sustainability committee of IHK Frankfurt. Finally, he works on normative basis for the mechanical recycling of plastics in a working group of the plastics committee within DIN, the German Institute for Standardization. There, he is one of the co-authors of DIN SPEC 91446, which describes the quality levels for plastic recyclates.

The background
The EU Commission recently submitted a draft regulation to combat pellet losses, about which we report elsewhere in this newsletter (see section: "From politics and industry"). The aim is to reduce discharges of plastic pellets from industrial plants into the environment throughout Europe, and to prevent microplastic being released unintentionally into the environment. We asked Mr. Zies about the challenges and concrete implementation measures with which a recycler is confronted when it is a matter of preventing the discharge of plastic pellets into the environment. We also asked him for a recommendation for recyclers and compounders against the background of study results, according to which some of the microplastic released into the environment actually originates from the recycling of plastic waste (see section "From science and research").

Mr. Zies, your company has been involved for over 60 years with the production of recyclate and compounds, so the handling of pellets is part of your everyday business. What are the biggest challenges in a company like yours when it comes to the prevention of pellet losses?


In our company, pellet losses are not really the main problem for us. Instead, we are involved with the compounding, which covers the steps leading up to the pellet: we process engineering plastics in the form of sprues and faulty parts as waste or by-products into regrind and agglomerate. Both the regrind we produce ourselves by grinding and the regrind we buy must be handled within the framework of our internal logistics in order to produce pellets again from this material. As far as the grinding is concerned, the important thing is to ensure that as little material as possible is lost during the grinding processes. Because the grinding is carried out indoors, the amount of material discharged into the environment is extremely small.
The main problems arise during the delivery and storage of the plastic waste, because contamination can arise here through material dropping out or falling off, for example when tiny plastic particles fall onto the ground from the delivered grid boxes. This material is, however, picked up again through regular cleaning measures. As part of our audit in accordance with DIN/EN/ISO 14001, we have also equipped the inlets in the work yard with sieve inserts that retain particles larger than 5 millimetres. In this area, there are also requirements from the approval and monitoring authorities, such as that the work yard must be kept clean and is to be cleaned periodically.
According to the results of the BKV’s "Special report pellet losses" compiled in 2022, plastics recyclers in Germany come up against pellet losses above all in the processes of filling recyclate into transport containers and, in internal logistics, on the company site (loading and unloading areas). What concrete internal measures do you have at MKV Kunststoffgranulate to ensure that no plastic granules are released into the environment? What in your opinion are the most effective measures?
MKV strives to minimise the losses of pellets during grinding and internal logistics, and also during production, as much as possible. Because the grinding and pelletizing processes take place indoors without any wastewater system, there can be no discharges of pellets into the water. Apart from that, the employees are trained to keep the working areas clean, something that is also illustrated by the environmental management system audited to DIN/EN/ISO 14001.
According to a study from Scotland, in which microplastic concentrations in the washing water were measured in a recycling plant, microplastic is also produced during the recycling process – above all during the shredding of the plastic waste – that can be released into the environment. What, in your opinion, is the most urgent need for action in the industry, and what recommendations do you have for plastics recyclers and compounders?
I can only comment on the topic of "Microplastic in the washing water" as Chairman of the compounders and recyclers in the TecPart industry association. As already mentioned, MKV does not use any washing water, but even the companies that do operate a washing facility are subject in Germany to the legal regulations of the Federal Immission Control Act, and thus have to comply with unambiguous regulations governing wastewater treatment. Every recycling begins with pretreatment of the waste, which mostly involves some kind of shredding. The recycler is required to keep the working areas as clean as possible and to ensure that, during transport, no damage occurs to the containers from which the regrind material or pellets can leak. It is important that both the supplied waste fractions and also the materials that are handled in recycling plants are carefully managed and that no part of it can be released into the environment.
Mr. Zies, many thanks for the interview!

(December 2023)

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