| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to well supply a molding material and to surely mold a golf ball with good moldability even if a relatively thin cover layer is formed around a core by providing this golf ball with a prescribed number of pieces or above of gate part. SOLUTION: The metal molds for injection molding are constituted by separably joining a pair of split molds (e), (e) and forming a spherical cavity (f) and the plural tubular gate parts (d) existing at the joint surface parts of both split molds (e), (e) and communicating with the cavity (f). The molding material is injected and supplied into the cavity (f) through the gate parts (d), by which the cover layer is molded around the core (g) arranged in the central part of the cavity (f) and the golf ball is produced. The golf ball is provided with >=10 pieces of the gate parts (d). As a result, the region to be packed with the molding resin from the one gate part (d)is made smaller and the sure and good supplying and packing the molding resin are made possible even if the gap between the core (g) and the cavity (f) arranged to form the thin cover layer is extremely narrow. |
