| 摘要 |
PURPOSE:To prevent the deformation of an unevenly thick-walled molded article and to make a uniform transfer of a mold surface to a molded article by a method in which a mold cavity is filled with a synthetic resin at a high speed, the operation is switched over to a dwell process and the dwell pressure is increased stepwise according to the state of cooling. CONSTITUTION:The injection filling speed of a synthetic resin into a mold cavity is preferably kept as high as possible with a resin temperature kept, unless flash, burning, jetting, etc., are caused. It is preferable to change over the stage from injection to dwell operation just before the generation of surge pressure. During the dwell period, the pressure is increased stepwise according to the state of the resin being cooled. Otherwise, in the course of the solidification of the molded article from a thin-walled part to a thick-walled part in sequence, when a resin temperature detected by each temperature sensor has reached a desired point between the flow stop temperature and the glass transition temperature of the resin, the dwell pressure is increased stepwise to control the pressure in the cavity detected by each pressure sensor at a specified value. |
