Mold for forming golf ball and golf ball manufactured using the same
A mold for forming a golf ball makes it possible to form minute dimples, and to improve mold release properties of the mold and wettability of the mold by a material when a urethane material is used for a cover layer. A mold according to the present invention is a mold for forming a urethane cover as an outermost layer of a golf ball, and includes: at least two split molds that are separably joined with each other, and that includes a cavity formed therein by the joining, the cavity being for forming the urethane cover; protrusions that are formed on a cavity surface of the split molds to form dimples of the golf ball; and a composite plating film that covers the cavity surface of the split molds, that comes into contact with a material of the urethane cover, and that contains a nickel-based matrix and fluororesin particles dispersed in the nickel-based matrix.
1. A mold for forming a urethane cover as an outermost layer of a golf ball, comprising:
at least two split molds that are separably joined with each other, and that include a cavity formed therein by the joining, the cavity being for forming the urethane cover;
protrusions that are formed on a cavity surface of the split molds to form dimples of the golf ball; and
a composite plating film that covers the cavity surface of the split molds, that comes into contact with a material of the urethane cover, and that contains a nickel-based matrix and fluororesin particles dispersed in the nickel-based matrix,
wherein the cavity surface which is covered with the composite plating film has a Vickers hardness of approximately 200 to approximately 400.
2. The mold according to claim 1 , wherein a base material of the split molds is made of pre-hardened steel.
3. The mold according to claim 1 , further comprising a support pin that supports a core of the golf ball in the cavity, wherein a surface of the support pin is also covered with the composite plating film.
4. The mold according to claim 1 , wherein the ratio of a surface of the protrusions for forming dimples with respect to the cavity surface of the mold is at least 70%.
5. A method of manufacturing a golf ball, comprising the step of forming a urethane cover as an outermost layer of a golf ball by using the mold according to claim 1 .
6. The method according to claim 5 , wherein the urethane cover has a thickness of approximately 0.2 mm to approximately 0.3 mm.
7. The method according to claim 5 , wherein the urethane cover has a Shore D hardness of approximately 30 to approximately 50.
8. The mold according to claim 1 , wherein the composite plating film is formed by being subjected to heat treatment having a temperature from approximately 330° C. to approximately 500° C.
9. The mold according to claim 1 , wherein the cavity surface which is covered with the composite plating film has a water contact angle of approximately 95° to 120° .
10. The mold according to claim 1 , further comprising a gas vent pin, wherein a surface of the gas vent pin is covered with the composite plating film.
11. The method according to claim 5 , wherein the composite plating film is formed by being subjected to heat treatment having a temperature from approximately 330° C. to approximately 500° C.
12. The method according to claim 5 , wherein the cavity surface which is covered with the composite plating film has a water contact angle of approximately 95° to 120° .
13. The method according to claim 5 , wherein the mold further comprises a gas vent pin, a surface of the gas vent pin covered with the composite plating film.