Fraunhofer-Business Area CleaningIn our new “ExpertTalk” interview series, a colleague from the Fraunhofer-Business Area Cleaning presents an innovative cleaning technology in more detail. What competencies, possibilities and limits the technology has and where it is used. Of course, there will also be one or two amusing anecdotes from our everyday life in the development of these technologies.
This time we interviewed:
Daniel Weile from the Fraunhofer FEP's Cleaning and Hygiene Technologies Group
What specific cleaning technology does your institute offer?
A particular highlight of our technological equipment is the vacuum suction blasting process. This system from the range of blasting processes with solid blasting media does not use compressed air to accelerate the blasting media to the component surface, but instead generates a vacuum in the treatment chamber on the object, through which the blasting media is first accelerated to the component and then directly extracted.
Which competences of your institute do you use to offer the technology?
Our expertise lies primarily in the adaptation of this process to very specific applications, including the development of technology for very specific blasting media. For example, in the field of restoration and conservation, depending on the cleaning task (and thus also the task of preserving cultural heritage), a different blasting medium with the right processing parameters must be used in order to selectively remove the contamination while leaving the sensitive and very fragile surfaces untouched in their historically valuable condition. Not only do we have a selection of almost 50 different abrasives, from very hard (corundum) to partially elastic (nutshell) to extremely fine (polyurethane foam), but we can also set any desired abrasiveness through targeted fine adjustment and monitoring of the process parameters. The development of online monitoring of the processing status during processing is already planned.
Why people should choose you instead of a solution from the market? What advantage does it offer the customer?
The vacuum suction blasting technology is available on the market, so anyone is free to use it. Typical application scenarios are, for example, graffiti removal and floor renovation - both applications with high area performance and robust surfaces. By using the well-known basic principle, our development aims at the locally very precise processing of very sensitive surfaces combined with our expertise in process control and monitoring.
Where is the technology mostly used, in which industry and for which cleaning tasks?
The system was developed and tested on highly sensitive cultural assets and surfaces of historical objects. That is why this is currently the preferred application. However, other sensitive surfaces such as optics or medical products as well as biomaterials, mechanically sensitive functional surfaces and coatings can also be cleaned with this system. In particular, local areas on large components, systems, ships, vehicles or buildings can be processed with blasting media without the blasting media and detached contamination contaminating the working environment, as the local work area is always encapsulated and extracted due to the principle. In general, this technology can be used wherever a layer needs to be removed but the layer underneath needs to remain protected.
Were there any funny or interesting incidents during the development or application of the technology?
An interesting aspect of this system is the observation of the beam particles in microscopic dimensions. Although a soft material cannot ablate a harder one, as has been shown several times in SEM images, “soft” jet particles can also penetrate other materials. For example, microcrystalline cellulose leaves tiny imprints on stainless steel, and once we even found a particle that was still “spiking” the stainless steel.
What does the future of this technology look like, where is it heading and what will come next?
In the future, the main focus of this technology will continue to be on preserving cultural heritage and treating historical objects. However, we do see potential in the local mechanical cleaning of metal components. Components with chemically sensitive functional surfaces are a field that has not yet been explored, as this is where the full potential of the technology could be unleashed.
What specific services do you offer in the field of cleaning technology? (Seminars, service, development of customer-specific process technology, ...)
Our activities are divided into 2 main areas:
Firstly, customer-specific (cleaning) process development along the entire process chain. This includes, for example, cleanability analyses, process optimization and process planning.
Our other pillar is training in the field of industrial cleaning of surfaces. We offer basic courses (3 days) or on-the-job training (just under a year) as well as customized training on specific issues.
What was the most interesting project you worked on in this area?
All projects are actually interesting, as they always provide new insights into other systems and technologies. It doesn't usually matter which industry you work for, as each company and each production facility has its own special features that need to be rediscovered every time.
From a technical point of view, the most exciting projects are currently those in the semiconductor industry. Particles have to be removed that make a human hair look like a skyscraper next to them, particles that are so small that they can no longer be seen with any form of visible light, and yet they still interfere with a process. This presents a real challenge that gets the mind racing.
Projects with a clear ecological focus (e.g. reducing water and electricity consumption, switching to more sustainable products, ...), on the other hand, are the most fulfilling projects, as you can pursue your work with the satisfying feeling of being able to contribute something good.