Method of producing a golf ball
View Patent ↗There is provided a method of producing a golf ball, capable of forming a cover to have a uniform thickness to produce a golf ball excellent in resistance to abrasion. The method includes a step to subject a cover material mainly composed of a thermoplastic resin to heat and compression molding to form a half shell, and a step to allow two such half shells to be arranged on a core or an intermediate layer, joined together, and heat and compression molded to mold the cover to have a thickness of 0.3 to 1.5 mm.
1. A method of producing a golf ball, including molding a cover material mainly composed of a thennoplastie resin into two half shells in turn arranged on a core or an intermediate layer and joined together and ten introduced into a mold formed of semispherical pieces, and heat and compression molded to allow a cover to cover the core, the method comprising:
a first step to form the half shells by a heat and compression molding process, and
a second step to allow the two half shells to be arranged on the core or the intermediate layer, joined together, and heat and compression molded to mold the cover to have a thickness of 0.3 to 1.0 mm, and wherein
in the second step, if the mold has a temperature T 1 ° C. and the half shells start to flow at a temperature T 2 ° C. T 1 minus 2 is set within a range of −3° C. to 10° C.
2. The method of claim 1 , wherein the half shell is molded to allow the two half shells to have a volume in total of 105% to 120% relative to that of the cover of the golf ball.
3. The method of claim 1 , wherein the second step includes a low pressure molding step exerting a pressure set within a range of 0.5 to 5 MPa and a subsequent, high pressure molding step exerting a pressure set within a range of 10 to 15 MPa.
4. The method of claim 1 , wherein the cover is made from thermoplastic polyurethane elastomer.