Method of making golf club of plastic composite material

Claim 1

A method of making a golf club of plastic composite material, in which a thermoplastic plastic material is used as a matrix, and in which a long fiber material is used as a reinforcing material, comprising the steps of: (a) making use of a tapered mandrel; (b) using an inner tube of an elastic and refractory material to fit over said mandrel; (c) wrapping orderly onto said inner tube with at least a matrix layer of said thermoplastic plastic material, and with at least a reinforcing layer of said long fiber material; (d) withdrawing said mandrel from said inner tube so that said inner tube having a laminated outer shell formed by said matrix layer and said reinforcing layer becomes a hollow tubular body, which has an end that is sealed and which is subsequently arranged in a molding tool; (e) heating said molding tool up to a temperature corresponding to the melting point of said thermoplastic material so that said thermoplastic plastic material becomes a molten thermoplastic plastic material; (f) introducing, under the condition that said temperature is maintained, a pressurized gas having a pressure into said tubular body in such a manner that said pressure of said gas is increased progressively and stepwise so as to force said molten thermoplastic plastic material to permeate uniformly the interstices of fiber bundles making up said long fiber material; (g) cooling said molding tool to bring about the completion of a curing process of said molten thermoplastic plastic material which fills the interstices of said fiber bundles; and (h) opening said molding tool to remove therefrom said golf club.

Claim 2

A method of making a golf club of plastic composite material, in which a thermoplastic plastic material is used as a matrix, and in which a long fiber material is used as a reinforcing material, comprising the steps of: (a) making use of a tapered mandrel; (b) using an inner tube of an elastic and refractory material to fit over said mandrel; (c) wrapping orderly onto said inner tube with at least a matrix layer of said thermoplastic plastic material, and with at least a reinforcing layer of said long fiber material; (d) withdrawing said mandrel from said inner tube so that said inner tube having a laminated outer shell formed by said matrix layer and said reinforcing layer becomes a hollow tubular body, which has an end that is sealed and which is subsequently arranged in a molding tool; (e) heating said molding tool up to a temperature corresponding to the melting point of said thermoplastic material so that said thermoplastic plastic material becomes a molten thermoplastic plastic material; (f) introducing, under the condition that said temperature is maintained, a pressurized gas having a pressure into said tubular body in such a manner that said pressure of said gas is increased progressively and stepwise so as to force said molten thermoplastic plastic material to permeate uniformly the interstices of fiber bundles making up said long fiber material; (g) cooling said molding tool to bring about the completion of a curing process of said molten thermoplastic plastic material which fills the interstices of said fiber bundles; and (h) opening said molding tool to remove therefrom said golf club.

Claim 3

A method of making a golf club of plastic composite material, in which a thermoplastic plastic material is used as a matrix, and in which a long fiber material is used as a reinforcing material, including the steps of: (a) making use of a mandrel having a tapered end; (b) wrapping orderly onto said mandrel with at least a matrix layer of said thermoplastic plastic material, and with at least a reinforcing layer of said long fiber material to form a tubular body provided with said mandrel and a laminated outer shell which is formed by said matrix layer and said reinforcing layer; (c) putting said tubular body into a mold cavity of a molding tool in such a way that said mandrel can be moved in a direction opposite to an axis of said tubular body; (d) heating said molding tool up to a temperature corresponding to the melting point of said thermoplastic plastic material; (e) moving stepwise said mandrel in a direction toward said tapered end of said mandrel, under the condition that said temperature is maintained while the process of moving said mandrel is in progress; and (f) allowing said molding tool to cool so as to remove said golf club from said molding tool.

Claim 4

A method of making a golf club of plastic composite material, in which a thermoplastic plastic material is used as a matrix, and in which a long fiber material is used as a reinforcing material, including the steps of: (a) making use of a mandrel having a tapered end; (b) wrapping orderly onto said mandrel with at least a matrix layer of said thermoplastic plastic material, and with at least a reinforcing layer of said long fiber material to form a tubular body provided with said mandrel and a laminated outer shell which is formed by said matrix layer and said reinforcing layer; (c) putting said tubular body into a mold cavity of a molding tool in such a way that said mandrel can be moved in a direction opposite to an axis of said tubular body; (d) heating said molding tool up to a temperature corresponding to the melting point of said thermoplastic plastic material; (e) moving stepwise said mandrel in a direction toward said tapered end of said mandrel, under the condition that said temperature is maintained while the process of moving said mandrel is in progress; and (f) allowing said molding tool to cool so as to remove said golf club from said molding tool.