| 摘要 |
An injection molding system for molding a hollow plastic article employs a hollow mold core having a longitudinal axis and a core runner cavity that has a uniform cross section throughout and which extends to the open end of the mold core. The mold core includes at least one core ejection gate and at least one core inlet gate leading from the outer surface of the core wall to the core runner cavity. When molding is performed in stages, there is it least one core ejection gate for each stage of molding. The core is clamped in between separate sets of molding blocks for each stage of molding. A core end closure cap having a core extension cavity aligned with the core runner cavity is used to close the open end of the mold core. A molten plastic is injected into the outer molding blocks and is confined to travel through the core inlet gate of the core without entering the mold cavity directly so that the molten plastic is forced to pass through the core runner cavity in order to reach the core ejection gates. Upon cooling, the core runner solidifies and is gripped and pulled longitudinally out of the core mold without leaving any residue of the plastic whatsoever.
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