Light, fast and a real technological advance from Chemnitz!

Prof Dr Lothar Kroll

The MERGE Lightweight Structures Research Centre has been located directly behind the lecture theatre building for a year now. The Chair of Lightweight Structures and Polymer Processing (SLK) recently celebrated its 10th anniversary there. We spoke to Professor Lothar Kroll about the rapid growth of his professorship and the unique cutting-edge research in Chemnitz.

You celebrated the 10th anniversary of your institute. When you think back. How did you feel when you started here in 2006?
Prof Dr Lothar Kroll: When I started here in June 2006, the future topic of lightweight construction was being established at the same time. My team consisted of around ten employees who had previously worked in mechanical engineering and design. However, we quickly realised that the topic of lightweight construction was gaining momentum and was of interest to many industries: the aim everywhere is to reduce material and production costs.

The research idea behind lightweight structural design is to save materials and make products more efficient and, above all, lighter. Where is this particularly interesting for you?
We primarily develop technologies for mass production. We are not primarily interested in composites that are used in small series, e.g. in aeroplanes. Not even a thousand of these are produced in Germany every year. In car production, we are talking about 500,000 units in some cases. If we manage to save material costs and weight in this large-scale production, we will ultimately achieve a much greater reduction in CO2 emissions.

So you are entering completely new territory with your research?
Definitely. To utilise lightweight construction in a mass market, you need completely different technologies. These are quite complicated. On the one hand, we rely on injection moulding with plastics, which enables very fast processes. On the other hand, we use technical textiles, as textile processes are also very fast. And now it's a matter of marrying these materials again in short cycle times.

Where have you already succeeded in doing this?
In the Audi R8, we reduced the weight of a battery tray, which is otherwise made of aluminium, by 40 percent and the production time by 30 percent. The VW Board of Management then nominated us for the Innovation Award and we won this prize, which includes all VW locations worldwide.
Another example: a current component is a motor mount for the e-Golf 7, where we can show that our technology works on the mass market. We reduce the weight by almost 40 per cent and the costs by 35 per cent. These are complicated process steps, because the devil is usually in the detail. Sometimes it's the little things that you haven't thought of, but which make the process impossible. Not only for us, but also for others. The difference is that we find a solution. This is real technological progress from Saxony. So complex that the Asians have not yet been able to copy it. That is an absolutely unique selling point. I see this as a special opportunity for Saxony.

200 employees now work at the SLK professorship. "We are now one of the largest professorships in Germany," says Prof Kroll with pride. In 2012, MERGE was established in Chemnitz as the first and only federal cluster of excellence in the field of lightweight construction research. MERGE is now part of a network of lightweight construction institutes that unites the Institute of Lightweight Structures, the affiliated institute Cetex and the Fraunhofer Research Centre STEX at IWU. In addition to the SLK professorship, the Institute of Lightweight Structures also includes the professorships of Sports Equipment Technology, Textile Technologies and three endowed professorships. Around 400 employees work on the topic of advanced lightweight construction technology in this lightweight construction network.

How important is industry for your research projects?
We have built a stable bridge between science and industry. Right from the start, we have tried to address questions from industry. The first two years were very tough. We didn't yet have any machines or flagship products. Back then, I used my contacts with companies to acquire third-party funding. This enabled us to almost double our team every year at the beginning. Today, we work very closely with our many industrial partners, especially those in Saxony. We discuss things on an equal footing. If the interfaces work well on a human level, then innovations are almost a sure-fire success. We don't do research in the Eiffel Tower here, but take our industrial partners with us.

To what extent are there advantages in the Chemnitz economy? Do you benefit from traditional mechanical engineering or machine tool manufacturing?
Chemnitz definitely has a strong mechanical engineering sector. What is even more decisive for us is the textile expertise at the location. With CETEX, STFI and Karl Mayer, there are traditional textile machine manufacturers and research institutes in Chemnitz. In order to turn carbon fibres into our fibre composite systems, for example, we need the textile technology processes that these partners have mastered.

Prof Kroll's list of functions and tasks is long. He is not only a university professor, but also Director of the Cetex An-Institute for Textile and Processing Machinery non-profit GmbH, Coordinator of the Federal Cluster of Excellence MERGE and the Chemnitz Alliance for Lightweight Textile Construction (ATL), Head of the Fraunhofer Research Centre STEX at IWU and Vice Dean of Research, International Affairs and Equal Opportunities at the Faculty of Mechanical Engineering. In his view, further proof of Chemnitz's strong textile research is the involvement of CETEX and Fraunhofer STEX in the VW research project Open Hybrid LabFactory, a unique industrial lightweight construction campus in Wolfsburg. "Industrial research for the lightweight construction of tomorrow is being driven forward here, and we are responsible for the entire textile production chain because the special textile machines from Chemnitz are needed here. We are proud to be at the forefront of this globally important development."

You also have the support of politicians. Your MERGE research project was set up as part of the Federal Excellence Initiative.
Politicians around the world are concerned about climate protection and resource efficiency. We fit in perfectly with this. The Saxon ministries have recognised the huge potential here. Thanks to the Federal Excellence Initiative, we have been able to employ staff and purchase equipment. The infrastructure was financed by the state. We can develop prototypes through to series components in our hall.

What does the MERGE machine do?
The basic principle is that it is an injection moulding plastic machine that can produce plastic parts in large quantities. We have now configured it so that it can do much more: it can marry materials such as plastic, textiles or even metal, it can mould metal in the plastic tool and we can embed sensors. We can produce complicated parts in one shot, which are then extremely light. We don't want to weld, screw or rivet. These processes take a long time. Everything should be automated and run in a single process. We want to shorten existing lightweight construction processes. An ICE coupling made of carbon fibre that we developed for Deutsche Bahn is half the weight of the original, but it takes almost a week to produce. That's too slow for the automotive industry. The aim is to have just a few process steps, otherwise you have to keep heating up and cooling down, which costs time and energy. We want to place textiles, metals and sensors in a mould and embed everything in the plastic in one shot.

The MERGE machine is located in a twelve metre high hall. "It can inject three different plastic components," explains the professor. And he and his team still have many ideas for expansion. "For example, we want to inject foam in addition to the hybrid components. The machine is unique in the world," the researcher is convinced. "And it comes from Chemnitz, you have to imagine that!" A second and third construction phase for the Lightweight Structures Centre is still to follow, when a laboratory and office building will be built next to the existing hall. The total investment will amount to around 30 million euros.

You are working on your dream of building the largest lightweight construction centre in Europe here.
We will succeed. And I have even more plans. We want to establish a new Fraunhofer Institute for Textile Engineering here. This will allow us to utilise the expertise that has grown from our history. This could be the renaissance of textile technology in Saxony. Not for clothing, however, but for high-performance components. The textile machines required for this are already being developed and tested. Some of them are world firsts.

How are you coping with the rapid growth?
It's a lot of pressure, and it's a challenge for all of us. I am glad that the university management is supporting this growth, although the structures are not designed for this. The administration is very challenged by our numerous projects, if only in terms of billing. But it is important to be visible. Without the help of the university, the ministry and the industry partners, we would never have managed to build something like this. It's a joint effort.

You also want to become more internationalised. What are your plans?
Of the 43 federal clusters of excellence, only our MERGE cluster was selected by the BMBF for internationalisation. And we are now involved with MERGEurope. We are now involving international partners and are starting with the neighbouring countries of Poland and the Czech Republic. We are already tackling our first industrial projects with Poland. We have also founded a European lightweight construction alliance, of which MERGE is a co-founder and will be appointed coordinator in a few weeks' time. If that works out, we will lead the European Lightweight Construction Alliance from Chemnitz.

What do you see as the great advantage of Chemnitz as a location?
What characterises Chemnitz is its strong SME sector. Here, friendships develop from the projects. Trust also leads to follow-up projects. It's a very uncomplicated way of working together. Many family businesses are more flexible when it comes to making decisions. It's like a family. And I didn't know that from my previous work with large companies.

Do you have to encourage the people of Chemnitz?
Yes, the people of Chemnitz don't communicate enough about what they can actually do. There are many hidden ideas and potentials here. In other locations, small things are marketed. And here in Chemnitz, great things are being created, but hardly anyone talks about them. The people of Chemnitz don't have to be a bunch of foaming at the mouth. It's enough for them to say what they can do.