| 摘要 |
PURPOSE:To offer a racket frame which has sufficient high strength as well as flexibility, as a whole, by reinforcing at least a part of a fiber reinforced plastic constituting racket frame with fused quartz fiber. CONSTITUTION:Plural kinds of wet prepreg are properly combined and are wound into a tube shape; after being set on a metal mold, the tube shaped is formed into a racket frame 10, by means of the so-called internal pressure forming method, under which materials are hardened with an internal pressure given in a high temperature. Thereupon, the whole racket frame 10 is made of fiber reinforced plastic and, for the intermediate part (part of throat B) between the part of head A and the part of grip C, fused quartz fiber reinforced plastic is principally used. Fiber reinforced plastic using the fused quartz fiber has elastic modulus as high as that of ordinary glass fiber but sufficiently lower than that of carbon fiber and its breaking resistance is as big as that of carbon fiber reinforced plastic. |
