Researchers are working on turbo skis

Novel waxes and pads make the equipment of racers even better

A transponder on the skier's leg measures the exact speed. This is how the researchers find out which wax makes skis faster. © Fraunhofer IWM
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In skiing, often only fractions of seconds decide on victory and defeat. The right material can therefore play a major role. Fraunhofer researchers have now simulated friction phenomena and gliding effects between skis and snow, developing novel waxes and rubbers - creating super-fast skis.

It could not be a better day of competition: the sun is shining at minus five degrees, the wind is still, the snow is perfect, and the biathlete is in top form. He is one of the best, he can win the race. Victory and defeat are often determined by just tenths of a second - making the ski very slippery. It depends on several factors, such as whether the wax mixture fits the snow cover.

Slipperiness of skis examined

Who wants to have the optimal ski, must understand the physical laws of friction. For this reason, wax and ski flooring manufacturers rely on the expertise of researchers from the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg. They have examined the slipperiness of skis and know how to make the athletes very fast.

"Snow, surface and wax are one unit, " says Professor Matthias Scherge from the new MikroTribologieCentrum Karlsruhe. "We can not change the snow, but we can adapt both the wax and the surface to the respective snow conditions."

Sliding effects on the track

Friction phenomena and gliding effects are analyzed by the researchers using a special method: using an apparatus, they simulate the contact between a single snow crystal and the coating. They measure the friction occurring as a function of the temperature. "The slip effects occur in the first ten to fifty nanometers of the pavement surface, " explains Scherge. display

In addition, the researchers have another device in use: the Skitribometer. On it, a piece of ski on a snowy disk drives in a circle. This allows engineers to test different combinations of waxes and linings and optimally adapt to conditions such as temperature.

Novel waxes and super fast coverings

The final rehearsal takes place in the ski hall. There, biathletes perform gliding tests on a 100-meter test track with a defined gradient. The time is measured - a transponder on the driver's leg ensures accurate results. This is how the researchers find out how many thousandths of a second the right combination of wax and coating makes the ski faster.

Together with the company Holmenkol and other partners, the researchers are thus developing novel waxes and superfast coatings. "We also spoke with athletes and with technicians who grow skis ahead of every competition, " says Scherge. Only with their knowledge and experience is it possible to make the perfect sliding ski.

(idw - Fraunhofer-Gesellschaft, 06.01.2010 - DLO)