| 摘要 |
PURPOSE:To eliminate defective molding by preventing the resin left at former molding from mixing with the resins for forming core layer and layer by a method wherein the resins left in the inner tubular nozzle hole of an inner tube and in the nozzle hole of a nozzle tip at former molding are removed by advancing a needle fittingly inserted in the inner tube. CONSTITUTION:A nozzle hole 4a is shut off from outside passage 15a by abutting the tip face 2a of the inner tube 2 against the inner face 4a at the tip of a nozzle tip 4 through the advancement of both the piston 7b of a first cylinder 7 and the piston 8b of a second cylinder 8, which is produced by supplying pressurizing fluid to the shown right side chambers of the first cylinder 7 and the second cylinder 8 respectively. In succession, only the piston 7b of the first cylinder 7 is advanced further so as to advance a needle 3 through a rod 7a in order to touch the tip of the needle 3 with the tip of the nozzle hole 4a. As a result, the inner tubular nozzle hole 2a is closed and, at the same time, molten resin left in the nozzle hole 4a at former molding is ejected so as to push the resin left in the runner sprue of a mold into the mold and, at the same time, remove said molten resin left in the nozzle hole 4a. |
