| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection molding method and an injection molding mold for turning a molding defective of the first shot at the beginning of starting molding production into a conforming article in regard to the injection molding mold having a hot runner structure. SOLUTION: The injection molding mold includes: a back flow prevention valve 7 disposed on a resin flowing-in port 6 of a hot runner of a stationary mold 1; and a valve gate 9 or a back flow prevention valve disposed on a resin flowing-out port 8 of the hot runner, whereby, before a resin extruder is separated from an injection mold when injection molding production is ended, all of the resin flowing-in port 6 of the hot runner of the stationary mold 1 is closed, thereafter, all of the resin flowing-in port 6 is closed by the back flow prevention valve 7, thereby, a resin pressure in the hot runner is retained in 40 Mpa to 80 Mpa by the resin extruder, the resin extruder is separated from the injection molding mold, the injection molding mold is cooled, thereby, the pressure in the hot runner is reduced and, as the result, the degree of volume contraction of the resin in process remaining in the hot runner is reduced to minimize a clearance developed in the hot runner. COPYRIGHT: (C)2009,JPO&INPIT
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