| 摘要 |
PURPOSE:To enable the title method to enlarge a projection area of a molding without generating a flash, by increasing gradually resin pressure in a mold at the time of dwell so that it may become maximum prior to completion of the dwell. CONSTITUTION:When resin pressure is set up sufficiently low at the time of filling of cavities 3... with molten resin A, and a quantity of mold break is made about zero, then a sink C is generated as the molten resin A does not spread to the corner of a cavity 3 sufficiently. When the resin pressure is raised a little and restored immediately to the former state, the cured layer B is not destroyed as the cured layer B is spread out by the molten resin, the sink C is eliminated and a quantity T1 of the mold break is little. When the resin pressure in a mold at the time of filling is increased gradually after the same has been maintained for a fixed period of time t2, though the quantity of the mold break also is increased, as the cured layer B also is increased, it does not happen that the cured layer B is destroyed through the resin pressure in the mold. Although the quantity T2 of the mold break also becomes maximum when the resin pressure in the mold becomes maximum, as the molten resin A is almost cooled and solidified, the molten resin A will not entered the gap between a stationary mold 1 and movable mold 2. |
