MOLD ASSEMBLY FOR MOLDING OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To make it possible to discharge the air in a product cavity to the outside from the gap between retaining molds at the time of filling of the cavity with a resin to prevent the protrusion of the resin from the gap. SOLUTION: The gap S between an outer periphery ring 52 and a stamper 27 and the gap S1 with the core block 46 of the outer periphery ring 52 function as gas vents when the product cavity 3 is filled with the resin but, when the mold clamping force of a fixed mold 1 and a movable mold 2 is increased, an annular groove part 58 is filled with the commpressed resin to prevent the protrusion of the resin from the gap S1. The projection d1 formed to the outer peripheral edge of an optical disk (d) by the annular groove part 58 gets away from the annular groove part 58 by the shrink of the resin and the projection d1 is not hooked with the outer periphery ring 52 at the time of release of the optical disk (d).