| 摘要 |
The invention is directed to a sports board ( 15 ). In the preferred embodiment, the board comprises an expanded polymer foam core ( 16 ), an extruded thermoplastic polymer outer layer ( 20 ) having an inner surface ( 21 ) and an outer surface ( 22 ), an expanded polymer foam intermediate layer ( 19 ) between the core and the outer layer which is laminated to the inner surface of the outer layer, the outer surface of the outer layer being substantially planar and having at least one series ( 23 ) of longitudinally extending, parallel and alternating grooves ( 26 ) and ridges ( 27 ), the series having a width ( 28 ) and the grooves and ridges spaced across the width so as to provide from about ten to about eighty grooves per inch of the width. The grooves may be spaced so as to provide about forty-five grooves per inch of the width. The grooves may have a depth ( 33 ) of from about 0.05 mm to about 1 mm. The depth may be about 0.4 mm. The core may be polyurethane foam, polyethylene foam, polypropylene foam or polystyrene foam, the outer layer may be polyethylene or polypropylene, and the intermediate layer may be polyethylene foam or polypropylene foam. Each of the grooves may have a width ( 34 ) and the combined width of all the grooves in the series may be from about twenty percent to about eighty percent of the width of the entire series. The combined width of all the grooves in the series may be about fifty percent of the width of the series. The width of the grooves may be uniform. The core may comprise two polymer foam outer layers ( 51, 52 ), a polymer inner layer ( 53 ) between the two outer layers, the inner layer having a density greater than the two outer layers. The core inner layer and the two core outer layers may be polyethylene or polypropylene. |
