Innovative industrial cleaning
All of us are faced with the same daily battle against the build-up of dirt. But while vacuum cleaners, dishwashers and washing machines can all quickly restore order to our homes, keeping industrial plants and equipment clean is an altogether different kind of challenge. Remarkable progress has been made in recent decades in virtually all industrial sectors in terms of the ecological efficiency of production processes. A great deal remains to be done, however, before we will have achieved full sustainability. We need to reduce atmospheric emissions - in particular those contributing to climate change - along with water pollution, energy consumption, the use of toxic substances and the quantity of non-recyclable waste. One of the key methods for meeting these challenges is through technological development. This involves improving the capacity of industry to innovate. The German Fraunhofer Institute for Surface Engineering and Thin Films IST has been looking closely into this issue and has come up with a solution for dealing with industrial plant cleaning. The challenge here is often in the detail, for example in the case of milk pasteurisation processes. Dissolved milk proteins tend to build-up in the pipes, boilers and heat exchangers of the equipment being used. After one working shift, they can be soiled to such a degree that the entire plant has to be shut down for cleaning. This translates into huge costs for manufacturers. Such deposits are referred to by experts as "fouling", and can severely disrupt production processes, costing between 5 and 7 billion Euros per year in Germany alone. To prevent fouling within plants, special coatings are needed to prevent proteins, salt crystals and calcium carbonate deposits from sticking to the surfaces of plants or system components. The difficulty in achieving this is that the types of deposits vary depending on the materials used and the liquids used. Scientists however have now found a way to adapt the coatings to a wide variety of different industrial applications and loads. They have achieved this by "custom tuning" the structures and surface energy of the coating surfaces. One important variable in this innovative solution is the surface energy of the coating. It determines to what extent deposits are able to cake on. "The range of properties relating to these layers range from high wear protection through to an extreme anti-fouling effect. With the help of special process technology, we are now able to create practically any desired property," explains Dr. Martin Keunecke, Head of Department for New Tribological Coatings at IST. The coatings are made up of carbon and other elements and are just a few micrometres thick. That corresponds to approximately 50 times thinner than a human hair. Both extremely hard and durable, carbon layers are characterised by excellent anti-corrosion and anti-wear properties. Their surface energy, and thereby cohesive properties, can be further reduced by integrating non-metallic elements such as fluorine and silicone. This leads to an additional anti-fouling effect. "Depending on the type and quantity of the elements used, we are able to control the properties of the coatings in a targeted way," explains Dr. Peter-Jochen Brand, Head of Department for the Tribology Transfer Centre at IST. "This is necessary because industrial plants are subjected to a wide range of differing stresses resulting from liquid substances. Just consider milk processing or fruit juice manufacturing in the foods industry, paint production in the chemical sector, production of medications in the pharmaceuticals industry or the transportation of crude oil." Industry currently uses carbon-based coatings primarily in order to reduce friction and wear. Although already in great demand, anti-fouling applications are still in their infancy. For this reason, Keunecke and Brand are anticipating fresh momentum from the market as a result of their innovation. Scientists will demonstrate the versatility of their new anti-fouling coatings at the Hanover trade fair by way of a recreated fountain. Here, water runs over the variously tuned surfaces and forms - depending on the degree of the anti-adhesive effect - different droplet patterns. "Now that we understand how to individually configure the layers, the next stage involves tackling the question of how to most efficiently produce the coated equipment. Anti-fouling already works extremely well for external surfaces, however, internal coating, for example for pipes, is anything but straightforward. For this reason, we are now collaborating with industry and research partners to create new manufacturing processes," concludes Keunecke. The Fraunhofer Institute for Surface Engineering and Thin Films IST will be exhibiting the anti-fouling application at the Surface Trade Fair in Hanover, Germany next month.For more information, please visit: Fraunhofer Institute for Surface Engineering and Thin Films ISThttp://www.fraunhofer.de/en/press/research-news/2013/march/tuned-coatings-ensure-cleanliness.html
Countries
Germany