| 摘要 |
PURPOSE:To constitute the title method that neither molding strain is generated nor a matter wherein a warp or crack is generated on a molded article does happen even if a large-sized and flat article is molded, by a method wherein mold clamping force at the time of cooling after injection and filling is controlled according to properties of molten resin. CONSTITUTION:Although injection and filling are completed at the time t2, a movable mold 10 keeps forward movement on at low speed and arrivew at l3 at the time t4. Under the above-mentioned state, at the time when the movable mold 10 has arrived at the time t5, an instruction signal is sent cut to an electromagnetic pressure control valve 30 for mold clamping force presetting through a control circuit 34, hydraulic pressure to be applied to a mold clamping cylinder 22 is controlled so that mold clamping force becomes of p3, the movable mold 10 is pushed back a little and arrives at a position p4. When the movable mold arriaves at the time t6, the instruction signal is sent out to the control valve 30 through the control circuit 34 again, the hydraulic pressure to be applied to the mold clamping cylinder 22 is controlled so that the mold clamping force becomes of p4 and the movable mold 10 is advanced a little and arrives at a position l5. When the movable mold 10 arrives at the time t7, the hydraulic pressure to be applied to the mold clamping cylinder 22 is controlled so that the mold clamping force is restored to the p2. |
