A composite material body (10) includes a first material layer (20) and a second material layer (30) overlapping the first material layer (20). The first material layer (20) and the second material layer (30) are wound to form a flexible and circular rod. Impact absorption is effectively improved and impact resisting strength is enhanced because energy-absorber or damping material or its composition is attached into the composite material body (10). Technical characteristics, effects and objects of this invention are achieved thereby.

A composite material body (10) includes a first material layer (20) and a second material layer (30) overlapping the first material layer (20). The first material layer (20) and the second material layer (30) are wound to form a flexible and circular rod. Impact absorption is effectively improved and impact resisting strength is enhanced because energy-absorber or damping material or its composition is attached into the composite material body (10). Technical characteristics, effects and objects of this invention are achieved thereby.

The invention relates to a frame for a ball game racket comprising a handle region and a head region with a bridge, wherein a part of the head region and/or the handle region comprise(s) a carbon fiber composite material and wherein the bridge comprises magnesium and is formed as one part.

A tennis racket includes throats. Each throat includes a fiber reinforced layer and a vibration damper. The vibration damper is surrounded by the fiber reinforced layer. The fiber reinforced layer includes a plurality of reinforcement fibers and a matrix. The reinforcement fibers are typically carbon fibers. The material of the matrix is a resin composition whose base material is an epoxy resin. The vibration damper is formed of a polymer composition. The polymer composition contains a base polymer. The base polymer is preferably a styrene-isoprene-styrene block copolymer or an acrylic elastomer.

A tennis racket includes throats. Each throat includes a fiber reinforced layer and a vibration damper. The vibration damper is surrounded by the fiber reinforced layer. The fiber reinforced layer includes a plurality of reinforcement fibers and a matrix. The reinforcement fibers are typically carbon fibers. The material of the matrix is a resin composition whose base material is an epoxy resin. The vibration damper is formed of a polymer composition. The polymer composition contains a base polymer. The base polymer is preferably a styrene-isoprene-styrene block copolymer or an acrylic elastomer.

A method of manufacturing a string 10 for use in a racket includes: (A) preparing an untreated string; and (B) irradiating the untreated string with radioactive rays. Preferably, the untreated string is irradiated with gamma rays. A preferable irradiation amount of the radioactive rays is greater than or equal to 250 kGy but less than or equal to 2000 kGy. Preferably, a material of the untreated string is polyester. Alternatively, the material of the untreated string may be nylon.

The inventive fiber manufacturing process is particularly adapted for demanding applications such as sports racquets, including tennis racquets, badminton racquets and other sports applications. Because of the improved strength to weight ratio of components formed using the inventive method, a wide range of flexibility is achieved, allowing use of the inventive process to manufacture, for example, a fiber reinforced (for example, graphite) modular sports racquet, optionally provided with user-selectable weights and/or handle replacements. From the standpoint of the player, this allows a racquet frame featuring self customization. From the standpoint of a retailer, the benefit provided is reduction of inventory. The inventive fiber, for example graphite fiber) racquet frame is filled with a plastic foam and is formed using, for example, microencapsulation technology to time, generate and apply the pressure used to form the graphite composite material of which the racquet is comprised. Advantageously, inner and outer tubular members may be used to form the racquet frame, with the inner tubular member extending around the head of the racquet frame. This compares to the standard industry technique of air injection. The racquet is thus not hollow like conventional graphite racquets, and the walls therefore can be made thinner than those of existing graphite racquets still being of the same strength or being stronger, which gives the racquet exceptional performance. In addition, the overall dimensions of, for example the cross-section, of the racquet can also be reduced while still maintaining performance characteristics.

Biodegradable handgrips, for example, for use in racquet sports, baseball bats, golf clubs, fishing poles, bicycle handlebars, and hand tools, are described. The biodegradable handgrips includes a petroleum based material and a biodegradable additive blended with the petroleum based material. The petroleum based material may be nylon, polyester, or polyurethane, and the biodegradable additive may be less than 5% of the handgrip by weight. The biodegradable handgrip may be shaped as a tape that is wrapped around a handle or a sheath that slides over a handle.

Biodegradable handgrips, for example, for use in racquet sports, baseball bats, golf clubs, fishing poles, bicycle handlebars, and hand tools, are described. The biodegradable handgrips includes a petroleum based material and a biodegradable additive blended with the petroleum based material. The petroleum based material may be nylon, polyester, or polyurethane, and the biodegradable additive may be less than 5% of the handgrip by weight. The biodegradable handgrip may be shaped as a tape that is wrapped around a handle or a sheath that slides over a handle.

A racquet including a frame including a head portion, a handle portion, and a throat portion. The head portion is a tubular structure including inner and outer peripheral walls, each having inner and outer surfaces. The head portion of the racquet being formed of a fiber composite material. The fiber composite material includes a plurality of ply arrangements. Each includes a pair of plies defining first and second angles with respect to a composite axis. A section of the outer peripheral wall from the inner surface to the outer surface includes at least three ply arrangements overlaying each other, and the first and second angles of at least two of the at least three ply arrangements being at least 35 degrees. When the racquet is tested under a racquet torsional stability test, the racquet has an angular deflection of less than 5.5 degrees about a longitudinal axis.