| 摘要 |
PROBLEM TO BE SOLVED: To produce an ultra-thin-walled molded part having a scarless ring formed to its gate area by injecting a molten material in a cavity for molding an ultra-thin wall with specific wall thickness at a high speed and further axially inserting a core pin in the cavity. SOLUTION: An ultra-thin-walled part having a scarless opening formed to its gate area is molded. This part has a wall thickness of about 0.05-0.5 mm, more pref., about 0.1-0.4 mm so as to have uniform thickness within a deviation range less than about +1-0.00127 mm over the whole of the molded part. The opening formed to the ultra-tin-walled part is formed to an annular area. In an injection molding system, a molten material is injected at a considerably high speed to perfectly fill a mold and the valve member of a core pin 8 excludes the molten material in the gate area to form a scarless gate and a slit-free or scarless gate area. |
