| 摘要 |
PURPOSE:To keep the interior of a mold under vacuum condition and consequently prevent the external appearance of a molded part from being marred by a structure wherein a heat-resistant sealing member is provided between a nozzle part, through which molten resin is injected, and the nozzle abutting part of the mold. CONSTITUTION:An annular sealing member 9 is fitted in the inner peripheral part of a nozzle abutting part 8. A tubular sealing member 10, the outer diameter of which is allowed to fit into the inner periphery of the sealing member 9 as tightly as possible, is fitted onto the outer peripheral part of a nozzle part 6 so as to seal between the nozzle part 6 and the nozzle abutting part 8 by closely contacting the nozzle part 6 with the inner periphery of the nozzle abutting part 8. The sealing member 9 consists of elastic material such as Teflon, silicone rubber or the like. The sealing member 10 consists of heat- resistant, comparatively hard material with low heat conductivity such as polyimide, ceramic or the like. Accordingly, no reduction of the degree of vacuum occurs when a mold 7 is evacuated and the vacuum is generated in the mold. In addition, no suction of the air in a cylinder occurs. Consequently, a molded part is perfectly prevented from being married its shape due to air pressure. |
