| 摘要 |
<p>PURPOSE:To prevent the failure of molding by automatically controlling the plasticization condition of resins by a method in which a preset pattern or speed of plasticization is compared with actual plasticization condition detected by a sensor and adjusted by a keyed sleeve device. CONSTITUTION:A raw material resin is supplied to a screw cylinder 2 through a keyed sleeve device from a hopper 4, plasticized and melted by a screw 3, and fed forwards. In this case, the speed of the screw 3 retracting as the rotation proceeds is detected by a speed sensor 9 and compared with a preset retraction speed of the screw 3 by a comparator 10. Then, the key 11a of the keyed sleeve device is radially moved in and out inside the groove of the screw cylinder 2 by means of a solenoid valve 12a and an oil-pressure cylinder 13a on the basis of the output from the comparator 10, and thereby the biting action of resin is regulated. Thus, failure of molding, such as silver streak failure, color dispersion failure, short shot, etc., can be prevented.</p> |
