Extrusion International 5-2022

87 Extrusion International 5/2022 PLASMA TECHNOLOGIES – FROM THE RESEARCH ing conventional joining procedures, the process can be carried out with- out any interruptions. To develop the complex sluice and vacuum systems, the required pump performance is currently being evaluated and a seal- ing concept is being devised (see pic- ture 1). Reusable and recyclable design in the deep tech startup company IonKraft The potential and innovative strength of the plasma technology for the circular economy is shown in the founding of the deep tech startup, IonKraft, which has its roots in the Institute for Plastics Processing. Ion- Kraft transfers scientific findings from plasma research to industrial produc- tion technology. Based on research and development work carried out in the 1980s at IKV, which has now led to marketable products in the form of interior coatings for PET bottles, Ion- Kraft is focused primarily on develop- ing a systems technology for the coat- ing of large-volume blow-moulded parts. After all, this type of packaging, which is frequently used, for example, in agricultural technology, also needs – for various reasons – to have barrier properties. Before now, this was only possible with multi-material systems that are unsuitable for recycling. The scaling-up of the process to larger vol- umes certainly makes fresh demands on the coating machine technology, which have to be met through new constructive modifications in the vacuum technology and also in the microwave technology. Furthermore, the sometimes aggressive agricultural products also make new demands on the PECVD barrier coat, which must also have media-specific resistance properties for this (see picture 2). The business project is being funded by the EXIST research transfer program of the Federal Ministry for Economic Affairs and Energy. Use of post-consumer polypropylene for food-contact applications The reuse of high-grade recycled plastics in packaging that comes into contact with foodstuffs is – with the exception of PET – not yet properly es - tablished. One of the main reasons for this is the authorisation regulations of the European Food Safety Author- ity (EFSA), which makes strict require- ments on the permitted migration of foreign substances from the packag- ing into the food. Plasma technology is also an obvious candidate for solving this problem: The good barrier prop- erties that are known to exist against water vapour, oxygen and carbon di - oxide should also provide very good resistance to the residual foreign sub- stances from recyclate material (see picture 3). The development and test- ing are being carried out on standard post-consumer recyclate (PCR) from the DSD (Duales System Deutschland). In the first step, the contamination of the recyclate and its absorption by foodstuffs is simulated with the aid of test substances. In a second step, suit- able coating systems are developed that may have to be coordinated to the specific substances. These coat - ing systems are subsequently tested for their suitability for reducing mi- gration. The research work is being supported by the partners Gizeh Ver - packungen GmbH & Co. KG and the Green Dot – Duales System Deutsch- land GmbH. The University of Pader- born is also providing assistance with its expertise in analytics. The approach being pursued can be applied to both rigid and flexible packaging. The research project described here offers enormous potential for achiev- ing the targets of the European Com- mission, namely to recycle 55 % of plastic waste by 2030, and thereby substantially increase the proportion of recyclate material used in plastic products. Institute for Plastics Processing at RWTH Aachen University (IKV) Seffenter Weg 201, 52074 Aachen, Germany Prof. Dr. rer. nat. Rainer Dahlmann, Rainer.dahlmann@ikv.rwth-aachen.de Picture 2: Schematic representation of recyclable barrier packaging for the chemical industry | Picture: IonKraft Picture 3: Development of migration barriers for treating post-consumer recyclates