The objective of developing novel coatings for jump skies is to reduce the friction between the ski sole and the ice surface of the inrun in order to increase the jump speed. It is known that an increase in speed leads to further jumps (rule of thumb: 1 m/s faster correlates to about 10 m). A problem consists in the objective measurement of the coefficient of friction under competition conditions (100 m inrun, acceleration from 0 to 100 km/h in about 5 seconds, same surface pressure). All known ice-tribometers use small-sized sample with too high surface pressures or accelerate much faster.
The base material of jumpski soles is defined by the International Ski Federation (FIS). Thus, it is compulsory to use an ultra-high-molecular-weight polyethylene (UHMW-PE) to manufacture jumpski soles. At the University of Applied Sciences Kaiserslautern, a procedure was developed to joint UHMWPE-tapes to rings without ridges. These rings are measured against the sliding partner ice on a test-rig (works like a belt sander) also developed at the University of Applied Sciences Kaiserslautern. The friction force is due to the deflection of an ice-sheet being form-fitted in a flat dish. The migration of coating particles can be eliminated by replacing the dish after each test run. The test-rig is situated in a cooled chamber at -8° C, the temperature defined by the FIS for the inrun.