| 摘要 |
PURPOSE:To prevent the generation of voids by providing a projection in a runner in a mold apparatus wherein runners, the cavities formed in close vicinity thereto and the gate connecting both of them are provided to the parting surfaces of both upper and lower molds. CONSTITUTION:The resin flowing through a main runner 16 is separated into the resin flowing through the central part of the main runner 16 and the resin flowing along side surfaces of the main runner 16 by fins 20a, 20b. The flow passage of the latter resin is closed by the dams 21a, 21b positioned on the downstream side of the fins 20a, 20b and the resin is cured in this state. That is, the initial resin receiving heat history most largely to be increased in its viscosity is blocked by the dams 21a, 21b before reaching the branch points C, D of cavity runners 17, 17 and the resin low in its viscosity is turned in front of the initial resin increased in its viscosity at the branch points C, D to suppress the involution of air and the generation of voids. By this method, the flow of the resin corresponding to the heat history of the resin flowing through the runners is controlled to prevent the generation of voids and the humidity resistance of a molding is enhanced. |
