Extrusion International 5-2022

86 Extrusion International 5/2022 PLASMA TECHNOLOGIES – FROM THE RESEARCH Recyclable Barrier Systems for Sustainable Packaging Plastics in the action plan for the circular economy Plastic products, especially in the packaging sector, are at the focus of attention in the transition to recy- clable product cycles. The quantity of resources used for packaging and, at the same time, the quantity of plas- tic waste is constantly increasing and will continue to rise in the coming years without intervention by indus- try, politics, research and consumers. For this reason, the fundamental re- quirements made on packaging ap- proved for the EU market are to be made stricter by 2030. The emphasis is being placed on the following as- pects: • Reducing the quantity of packag- ing and packaging waste by lowering the complexity of packaging – includ - ing a reduction in the number of ma- terials used • Encouraging the reusability and recyclability of packaging through suitable design • Fixing rules for the safe and reli - able recycling of plastics other than PET for use in food contact applica- tions These areas of focus lead on to technical issues that can be tackled with the help of plasma technologies. The Institute for Plastics Processing at RWTH Aachen University (IKV) has been carrying out research for many years in this field, and is currently de - veloping highly functional coating systems for various specific fields of application in the field of packaging: Reduction of complex (multi-material) packaging through plasma technology Complex multi-layer composites consisting of different plastics that in each case fulfil a necessary packag - ing function are currently still heavily represented in packaging technol- ogy. At the end of their useful life, these composites can be used only for energy recovery because they cannot be segregated into their vari- ous constituents. With the help of the Plasma Enhanced Chemical Va - pour Deposition (PECVD) technol - ogy, plastics can be provided with a high-quality gas barrier that does not impair the recyclability of the plas- tic. In the discussions on the circular economy, the plasma technology has developed into a highly dynamic area of research with a broad relevance and key innovative force. The market for flexible packaging is facing major changes because of the challenges that will come about in the transition to the plastic circular economy. Although plastic film is now already being successfully provided with a barrier coat in discontinuous "roll-to-roll" coating processes, there is at present still no continuous pro- cess variant that eliminates the non- productive times that are unavoidable in present batch processes and hinder the overall aim of improving the eco- nomic efficiency of the process. The target is therefore to overcome this problem with the help of an innova- tive machine development for con- tinuous PECVD film coating. Here, the film is unwound under ambient pres - sure and passed through a sluice sys- tem into a vacuum chamber, in which a SiOx coating is efficiently applied through a so-called "in-plasma con- cept". Subsequently, the film is again passed through a sluice system at ambient pressure and wound up. Us- Picture 1: Experimental setup for the pump design IKV develops recyclable packaging solutions with the help of plasma technologies With the European Green Deal, the European Commission also approved inMarch 2020 a new "Circular Economy Action Plan – for achieving a cleaner andmore competitive Europe". The aimof this action plan is to encourage the use of sustainable products, business models and services, to adapt consumption patterns with the target of avoiding or reducing waste, and to establish in the EU a well-functioning internal market for high-grade secondary rawmaterials. Products should then in future, through a circular economy system, be of better quality, more resource-efficient and energy-efficient and, as part of this process, be designed for reuse and repair and for high-quality recycling.