Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-05-15
2001-12-25
Medley, Margaret (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S428000, C524S437000, C508S155000, C508S172000
Reexamination Certificate
active
06333376
ABSTRACT:
The invention relates to a plastic ski coating with a particlelike filling material addition improving the sliding characteristics.
For plastic ski coatings preferably materials with a hydrophobic character are applied, such as for example polyethylene.
The sliding mechanism on snow or ice with skis to which here are also counted “snowboards” is a complex procedure and is not known in every detail. One always assumes that roughness peaks of the running surface come into contact with the snow crystals and the frictional heat produced with this leads to their melting. The water which with this is produced locally between the running surface and the snow leads to hydrodynamic lubrication conditions, by which means the low kinetic friction coefficients of about 0.02 to 0.05 may be explained. The kinetic friction coefficients with solid body friction without hydrodynamic lubrication measured on skiing lie about
10
times higher.
Furthermore it has been shown that with higher speeds the locally formed melting water has the tendency to widen out over the whole running surface which leads to an undesired “suction effect” negatively influencing the sliding speed. By way of admixing materials such as for example carbon in the modifications of soot and/or graphite, which with respect to the non modified polyethylene matrix have a high heat conductability, this negative “suction effect” may be prevented or reduced (cf. e.g. CH-A-657993 or CH-A-660018).
The superiority of running surface materials of C-modified PE with respect to the sliding speed has in the last years led to the fact that they make up the greatest part of the ski coating used in ski manufacture. These ski coatings contain the filling material carbon in a relatively large quantity. Caused by the intrinsic colour of carbon in the modifications soot and graphite, these fast-sliding ski coatings have a black colour.
The object of the invention lies in providing a filling material addition which for the desired sliding properties may be added to the ski coating in a significantly lower quantity than the usual carbon and with which the black colouration may be avoided so that the ski coating may be formed with regard to colour by the addition of suitable colourants.
The plastic ski coating according to the invention with which the object is achieved is characterised in that the filling material addition contains at least one of the following substances: boron, at least one boron compound, at least one nitride.
As a nitride the filling material addition may usefully contain boron nitride.
In the preferred embodiment form the filling material addition thus contains at least one of the following substances: boron, boron nitride, aluminium nitride.
The filling material addition may additionally also yet contain carbon in the form of soot and/or graphite.
The quantity of the filling material addition is as a rule 0.2 to 20, preferably 0.5 to 3 parts by weight to 100 parts by weight of plastic. The used plastic may usefully be ultra-high molecular low-pressure polyethylene with a molar mass of 4 to 12×10
6
g/mol, which is processed in a press-sintering method, or low-pressure polyethylene with a molar mass of 200,000 to 600,000 g/mol, which is processed in the extrusion method.
REFERENCES:
patent: 5409622 (1995-04-01), Chapman et al.
patent: 66193A (1986-02-01), None
patent: 657993 (1986-10-01), None
patent: 660018 (1987-03-01), None
IMS Kunststoff AG
Medley Margaret
Shoemaker and Mattare
LandOfFree
Plastic ski coating does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plastic ski coating, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plastic ski coating will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2574271