| 摘要 |
PROBLEM TO BE SOLVED: To certainly prevent the damage of a heating barrel and a screw by appropriately detecting an unusual supply condition of a resin by the screw in the heating barrel. SOLUTION: In conducting molding operation or purge operation the back pressure of the screw 7 and the number of revolutions of the screw are set. Immediately after the start of the molding operation, since the pressure of the molten resin having been supplied to the head side of the heating barrel 6 is low and the retreat speed of the screw 7 is slow, the screw 7 is revolved in a low revolution mode. By the revolution of the screw 7 the pressure of the molten resin supplied to the head side of the heating barrel 6 becomes high, and the screw 7 retreats by accompanying this. The pressure of the molten resin supplied to the head side of the heating barrel 6 and the retreat speed are monitored, and when either of them reaches a set, predetermined value the control means 20 switches over the screw 7 from the low revolution mode until then to a usual revolution mode. By this the damage due to metal-to-metal contact between the inner wall of the heating barrel 6 and the screw 7 can be prevented. COPYRIGHT: (C)2009,JPO&INPIT
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