| 摘要 |
PURPOSE:To fix a stamper at the time of injection molding and prevent the stamper from being damaged, by a method wherein two kinds of flow paths are connected with each other through a valve which is opened only when the degree of vacuum of a cavity becomes higher than that of the flow path attracting a rear side of the stamper. CONSTITUTION:When a movable mold 40 is moved to a stationary mold 10 side and a cavity 30 is made, the cavity 30 is deaerated through a stationary mold outer circumferential flow path 14. Then a movable mold flow path 46, movable mold inner circumferential flow path 44 and movable mold outer circumferential flow path 45 are deaerated and a rear side of the stamper 20 is attracted to the stationary mold. At this time, when the degree of vacuum of the cavity 30 becomes higher than that of the flow paths 44, 45, 46, a valve 450 is opened and the degrees of the vacuum become identical with each other. On the one hand, when the degrees of the vacuum of the flow paths 44, 45, 46 attracting the rear of the stamper 20 is higher than those of the cavity 30, the valve 450 is closed. Namely, when resin is cast into the cavity 30 from a resin flow path 12, the stamper 20 is attracted to a cavity 30 side and does not rise from the movable mold 40. |
