Participants from industry, research and development discussed new approaches for technologies such as PVD, CVD and plasma nitriding at the workshop "Circular Economy - Strategies for Sustainability & Efficiency in Surface and Thin Film Technology" on December 3 and 4, 2024. In addition to enriching discussions and new contacts, the successful workshop provided in-depth insights into the energy intensity of coating processes and innovative solutions for conserving resources.
Energy-intensive processes as a starting point
The central topics of the workshop were the high energy intensity of coating processes - around 80% of the process output goes into the cooling system alone - and the recycling of materials. This fact underlines the urgency of more sustainable approaches in coating technology and provided the basis for the discussions and presentations.
Introduction to the circular economy
Sustainability andCO2 balancing: Prof. Dr. Markus Michael, Texulting GmbH, opened the session with the basics of sustainability and its anchoring in the three pillars of ecology, economy and social issues. Michael placed current developments in the context of political objectives and legal regulations, such as the EU action plan for the circular economy. Prof. Michael paid particular attention toCO2 balancing. Within Europe, this is easy to implement thanks to the existing regulations, but it remains a major challenge outside the EU. The long-term goal of the circular economy is the provision of equivalent materials with consistent quality and a reduction inCO2 emissions. Michael sees a key to this in product design: it must be geared more towards reusability, but this is a lengthy process.
Energy efficiency in surface technology:
Dr. Marcus Hans, RWTH Aachen University, looked at sustainability specifically in the context of surface technology. He pointed out that the term sustainability was first coined in 1713 in forestry and is more relevant than ever today. In his presentation, Dr. Hans analyzed the process control of PVD technologies (physical vapour deposition) and showed the energy requirements of the individual process components. He drew attention to the high energy requirements of PVD systems in standby mode - a system in standby mode consumes around 90 % compared to a processing system. Hans presented possible strategies for the use of recycled materials. As a solution, he suggested the use of material targets from metal returns, which, depending on the required coating properties, could have a high potential for coating applications despite atomic impurities. Resource-conserving processes with regard to global sustainability goals are an important lever for future-oriented material developments.
Legal framework conditions and recycling strategies: Gregor Dietz, SEW-Eurodrive GmbH + Co KG, looked at the legal aspects of sustainability and linked these to the topics of digitalization, supply chain and safety. Among the numerous directives and regulations - including REACH, RoHS and CSRD - he focused on those that are relevant to the circular economy. Particularly noteworthy is the so-called "R-concept", a collection of circular strategies that address different phases of the product life cycle: Refuse, Rethink; Reduce by design; Reuse; Repair; Refurbish; Remanufacture; Repurpose; Recycle; Recover. These strategies aim to reduce the use of energy and resources and extend the service life of products.
" Within Europe, the circular economy is easy to implement thanks to existing regulations, but it remains a major challenge outside the EU. "
Sustainability through plant retrofits
In the plant retrofit session, experts presented key aspects for extending the service life of existing plants and promoting sustainability in coating technology and discussed various approaches, challenges and potential for making existing plants not only more efficient but also more sustainable.
Longevity as the basis for sustainability: Andreas Böhm, Plasmanitriertechnik Dr. Böhm GmbH, opened the session by stating that thin-film and surface technology systems can be used for decades - up to 50 years - if they are well maintained. This longevity is sustainable per se and only requires regular maintenance and the replacement of wearing parts. At Plasmanitriertechnik Dr. Böhm GmbH in particular, where systems are designed and manufactured in-house, compatible connection concepts ensure central visual process monitoring.
Preventive maintenance can be optimized through networking and continuous data recording, which increases the availability and productivity of the systems. Andreas Böhm shared a practical experience: replacing an air conditioning compressor with a second external cooler reduced his company's energy requirements by 100,000 kWh per year - an impressive example of the impact of small, pragmatic steps. His conclusion: sustainability does not always have to be achieved through complex measures, but can often be improved through targeted optimization.
Digitalization and modern control technology: In his presentation, Frank Geißler, Kontron AIS GmbH, highlighted the diversity of systems and the resulting connection concepts and data volumes. While wearing parts need to be replaced regularly, control and regulation technology also requires regular upgrades to ensure the long-term availability of the systems. Modern control systems offer intuitive operability, facilitate the interpretation of system reactions and improve cybersecurity - an increasingly important aspect in view of regulatory requirements such as NIS-2 and the EU Cyber Resilience Act (CRA). These laws not only affect large companies, but also indirectly smaller suppliers, which makes the entire supply chain responsible.
Sustainability through automation: Aaron Strobel, LSA GmbH, recommended that sustainability measures should not be controlled by regulations alone, but should be based on the three pillars of ecology, economy and social responsibility. He posed the question of whether energy-intensive vacuum coating systems can be sustainable and gave a differentiated answer: The resource balance of a product depends on many parameters (such as logistics), not just the energy consumption of the production system. Thanks to increased productivity, automation offers enormous potential for reducing downtime and thus conserving resources. Strobel argued that effective automation not only benefits large companies, but also small and medium-sized enterprises.
Intelligent material design for the circular economy: Dr. Stefan Facsko, Helmholtz-Zentrum Dresden-Rossendorf, presented the EU project ReMade@ARI. It supports scientists in developing reusable materials that are more durable, easier to repair and easier to recycle. ReMade@ARI provides access to over 50 European research institutions and thus promotes the transition to a genuine circular economy.
" Sustainability measures should not be controlled by regulations alone, but in terms of the three pillars of ecology, economy and social responsibility "
Sustainable process management through retrofitting
Speakers in the session "Retrofit for process control" presented innovative approaches to increasing efficiency and sustainability in thin-film and surface technology.
Improved yield through tubular magnetrons and process monitoring: Thomas Vartiainen, Avaluxe International GmbH, opened his presentation with a problem diagnosis: classic sputtering and evaporation processes are characterized by a low material yield. However, tubular magnetrons increase the yield to an impressive 70 to 80 %. This technology also offers a four times longer service life compared to flat targets. Vartiainen also emphasized the importance of optimized process monitoring. Unwanted water residue during vacuum drawing, for example, can have a negative impact on coating quality. Improved monitoring makes it possible to minimize such effects, increase reproducibility and ultimately reduce energy consumption. Another promising approach for the future is so-calledCO2 tools, which make the ecological footprint of processes visible. However, Vartiainen also pointed out the challenges: a large proportion of the coating material is not deposited on the component, but on the system surfaces. Although recycling measures for the remaining target residues are important, these are often not implemented for economic reasons. The speaker emphasized that higher material utilization and the integration ofCO2 savings potential could create significant added value here.
AI-supported process control for plasma nitrocarburizing: Henrik Zimmermann, neoplas control GmbH, continued the discussion with a look at active process control. This is where modern AI methods for optimizing plasma nitrocarburizing processes come into play. Direct surface measurements in such processes are often impractical, which is why new approaches focus on monitoring molecular plasma process variables in real time. The combination of continuous gas injection and intelligent process control makes it possible to increase energy efficiency and improve process stability at the same time. Zimmermann presented how a retrofittable trace gas sensor can be tailored to specific customer requirements. This not only optimizes process stability and reproducibility, but also shortens process times and increases overall functionality.
Thomas Vartiainen, Avaluxe International GmbH, spoke about the improved metal yield in classic sputtering and evaporation processes - Photo: EFDS
Recycling and environmental technology
The "Recycling & Environmental Technology" session focused on innovative approaches to promoting sustainability in the production and use of resources in PVD technology and in the solar industry. Experts presented strategies and technologies that not only improve resource utilization, but also drive the transition to a circular economy.
Simulation and process design for sustainable PVD processes: Rolf Schäfer, robeko GmbH & Co KG, took a comprehensive look at the entire cycle - starting with simulations and ending with recycling in PVD technology. He presented two software solutions that calculate optimized process control based on specified layer properties. A central point of his presentation was the future integration of simulation and hardware. This combination should extend the service life of systems and improve process stability at the same time. In the second part of his presentation, he focused on the design aspects of target and magnet systems. He showed how the selection of the sputter source and geometric adjustments can influence the utilization of materials. By optimizing campaign life and taking waste and recycling capabilities into account, economic efficiency can be significantly increased.
Strategies for a sustainable material cycle of sputtering targets: Dr. Ruben Wagner, GfE Fremat GmbH, introduced the strategies of a sustainable material cycle in his presentation, with a special focus on sputtering targets. He shed light on the entire material chain - from the provision of raw materials to target production and the requirements of the recycling process. He showed how close cooperation between target manufacturers and users can optimize the geometry of targets and increase material utilization. His presentation emphasized that efficiency in the use of raw materials is crucial to achieving both economic and environmental benefits. One important aspect was the development of concepts for returning remaining waste products to the raw material cycle. Wagner presented various approaches on how used sputtering targets can be reused and explained the associated technical and economic challenges.
Challenges in the circular solar industry: Jan Bargel, Solar Materials GmbH, gave an insight into the challenges and potential of a circular solar industry. The economic drive is based on the recovery of silver - the most valuable material in solar modules. This was demonstrated using the recycling strategy of complex solar modules. The increasing demand for efficient recycling processes was identified as a key challenge for the coming years. The presentation emphasized that it is not only a matter of recovering materials, but also of reintroducing them into the production cycle in a meaningful way.
" The optimization of PVD processes, efficient recycling strategies and the promotion of circular approaches in the solar industry illustrate the synergy between sustainability and economic efficiency."
Sustainability and innovation in coating technology
The workshop highlighted a variety of approaches, challenges and opportunities for promoting sustainability in surface technology. Technological, economic and ecological aspects were considered comprehensively. The implementation of sustainability strategies requires technological hurdles to be overcome and economic framework conditions to be taken into account. In particular, the recovery of materials in an equivalent state remains a challenge that requires innovative approaches such as the use of less pure materials. The determination and future integration of theCO2 footprint into production processes could also give companies a competitive edge by opening up transparency and optimization opportunities.
Retrofit measures and simulation technologies have been identified as key factors in extending the service life of equipment, minimizing downtime and increasing added value. Even small advances in efficiency improvements can bring significant benefits in practice and emphasize the need for realistic innovation management.
The technical modernization of existing systems - combined with targeted automation and intelligent material design - offers a sustainable solution for combining ecological and economic goals. Pragmatism, such as the replacement of individual components or the optimization of existing systems, can have a major impact here.
The potential of the circular economy was particularly emphasized in the "Recycling & Environmental Technology" session. The optimization of PVD processes, the development of efficient recycling strategies and the promotion of circular approaches in the solar industry illustrate the synergy between sustainability and economic efficiency.
The EFDS workshop highlighted the enormous challenges facing companies in the surface and thin-film industry. It showed that the challenges of implementation can also be seen as opportunities. Cooperation, innovative approaches and close integration of research and industry can not only achieve ecological goals, but also secure competitive advantages. The strategies and technologies presented lay the foundation for sustainable, efficient and future-oriented surface technology.
Due to its topicality, the EFDS will address this complex of topics in the workshop "Raw material supply of the future - circular economy: challenges and opportunities for thin-film technology materials" on April 8 and 9, 2025 in Kempten. In addition, the international conference V2025 from October 13 to 16, 2025 in Dresden will deal intensively with the topics of sustainability, resilience and the circular economy.
