Tuned coatings ensure cleanliness

Since contaminated industrial plants cost billions every year special coatings are needed to prevent the build-up of contaminants. Researchers can now adapt ultra-thin coatings for an extremely wide range of applications.

All of us are faced with the same daily battle against dirt. Nevertheless, once  laziness is  overcome, vacuum cleaners, dishwashers or washing machines can restore order in our homes relatively quickly. However, keeping industrial plants and equipment clean is a different kind of challenge entirely.

In such cases, the devil is often in the detail, as is the case in, for example, milk pasteurisation processes. Dissolved milk proteins tend to build-up in pipes, boilers or heat exchangers of the equipment being used. After one working shift they are already 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, that are referred to by experts as ''fouling'', can disrupt production processes. Studies suggest that this results in costs of between €5 and €7 billion per year in Germany alone.
Tailor-made for every requirement

At the Surface Trade Fair (8 to 12 April, Hall 3, Stand D25) in Hanover, Germany, the Fraunhofer Institute for Surface Engineering and Thin Films (IST), based in Brunswick, Germany, is exhibiting a range of technologies that prevent fouling within plants in the first place.

Special coatings 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 to manufacture the plant and the liquids used.

Scientists have now found a way to adapt the coatings for a wide variety of different industrial applications and loads. They achieved this by ''custom tuning'' the structures and surface energy of the coating surfaces. One important variable in this formula 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).