In order to avoid the inward heat flow, which occurs in every clutch, the inner discs are coated with special sinter material. This sinter material has an insulating effect due to its specific consistency. Therefore the occurring heat must flow outwards, towards the larger cooling surface. Heat accumulation in the shaft and bearings is avoided. 

Usually the carrier of the inner disc is driven. In this case the moment of inertia of the outer parts and the housing is not increased by the mass of the coating which, of course, also has to be accelerated respectively decelerated all the time. 

Continuous temperatures of 150° C are admissible with temperature excursions of 200° C - 300° C in dry operation, as are continuous temperatures of 200-300°C, with temperature excursions of 400-