| 摘要 |
PURPOSE:To arrange so that resin leakage from an extended nozzle gate and a sleeve gate may be prevented and at the same time, resin coagulation inside a hot runner is also prevented by building a needle valve mechanism into an extended nozzle on a core plate side and the inlet of a hot runner on a cavity plate side. CONSTITUTION:After the completion of filling resin, the pressure of resin in a hot runner 10 is reduced by sucking it back. In addition, needles 15, 21 are advanced with time differential resulting in the closing of a gate 20 for an extended nozzle 19 and a gate 16 (inlet of the hot runner) for a sleeve 13. Under this condition, the gates 16, 20 are completely sealed and resin leakage does not occur during die opening. Further, it is possible to adjust temperature arbitrarily by a band heater thus eliminating resin coagulation. |
