Cross-country ski sole

A ski sole comprising a composite polyethylene film having embedded therein a plurality of polyethylene particles having a higher hardness than the polyethylene film, and having surface characteristics to reduce the adhesion between the particles and the film base which would normally be obtained, said hardness of said particles being sufficiently high and the adhesion being sufficiently reduced such that when the surface of the composite is abraded under skiing conditions, a plurality of fibrils extending from the surface of the composite film are developed at the interface of the particles and the film.

A ski sole comprising a multi-phase composite structure comprising a polyethylene film base having embedded therein a plurality of non-film forming polyethylene particles having a higher hardness than the polyethylene film base, the difference in hardness between the particles and the film being sufficient to create frictional discontinuities and the adhesion between the film and the particles being sufficiently reduced so that abrasion of the multi-phase structure under skiing conditions causes the formation of a plurality of fibers at the interface of the particles and film which fibers extend from the surface of the multi-phase structure.

A method for making a multi-phase polyethylene structure comprising film-forming polyethylene and polyethylene particles having a higher hardness than the film-forming polyethylene and which polyethylene particles will not form a film under film-forming conditions which comprises:

• (1) treating at least part of the surface of the polyethylene particles with a material which is incompatible with polyethylene or which will reduce the adhesion of the particles to the film-forming polyethylene,
• (2) mixing the treated polyethylene particles with the film forming polyethylene, and
• (3) forming a film of the mixture so that the treated polyethylene particles remain substantially intact to produce a multi-phase structure having polyethylene particles embeded in a film of polyethylene.

A method for making a multi-phase polyethylene composite comprising a film-forming polyethylene and polyethylene particles having a higher hardness than the film-forming polyethylene and which polyethylene particles will not form a film under the film-forming conditions which comprises:

• (1) treating at least part of the surface of polyethylene particles with a material which is incompatible with polyethylene or which will reduce the adhesion of the particles to the film-forming polyethylene,
• (2) mixing the polyethylene particles with the film forming polyethylene, and
• (3) forming a film of the mixture so that the treated polyethylene particles remain substantially intact to produce a multi-phase structure having polyethylene particles embedded in a film of polyethylene, said film forming polyethylene having sufficiently reduced adhesion to the embedded polyethylene particles of higher hardness so that a plurality of fibers are formed extending from the interfaces of the particles and film of the multi-phase structure when the surface of the structure is abraded on snow.