Process for the production of undersurfaces of skis, ski-undersurface prefabricated with a so produced undersurface as well as a ski with such an undersurface or undersurface prefabricate

摘要

For producing an undersurface for skis, a material is produced in band form from a polyethylene having an average molecular weight (weight average) in the range between 5.105 and 8.106 by a ram extrusion process, a relief-like surface structure being formed on at least one of the surface sides of the said material before it cools, the said structure being intended to improve the sliding properties on the snow on the running side and improve the bonding properties of the undersurface on the bonding side. This surface structure, the roughness height Ra of which lies in the range of just a few mu m, is impressed in the material to create fine surface grooves or ribs by corresponding shaping of the contour of the die orifice at the extruder output or, for example, in a band press by the structure of a fabric running along with it. This undersurface is preferably produced in ski production in the form of an undersurface prefabricate on which the undersides of the steel edges of the ski are flush with the upper edges of the ribs of the said undersurface. IMAGE