| 摘要 |
PURPOSE:To prevent molten resin sufficiently from leaking by drawing a screw in the direction opposite to the direction in an injection molding time and at the same time rotating the screw in the direction opposite to the direction in an plasticizer metering time. CONSTITUTION:When the screw 1 is drawn and sucked back at the end of plasticizer metering by the screw 1, the molten of the barrel 2 to the screw 1 is shown by a vector 11, and when the screw 1 is rotated in the direction opposite to the direction in the plasticizer matering time, the rotation of the screw 1 is shown by a vector 12, and the partial forces of a vector 13 obtained by synthesizing the vectors 11 and 12 are given by 13a and 13b. The partial force 13a acts along the screw flight 1a. When this is compared with the partial force 10a or 10b, that direction is clearly opposite to each other. Therefore, the pressure of the molten resin around the screw 1 is lowered by the back-flow valve 3, the entry of resin through the back-flow valve 3 is reduced remarkably, therefore, the leakage can be prevented. |
