| 摘要 |
PURPOSE:To prevent mixing of oxygen from outside into an extruding machine upon sucking by vacuum by a method wherein an air feeding and discharging port, provided near the connecting part of a loader and a hopper, is opened to feed the material of plastics into the loader by vacuum feeding under introducing atmosphere. CONSTITUTION:The openable air feeding and discharging port 16 provided near the connecting part of the loader 19 and the hopper 12. The material of plastics is fed into the loader 19 from a material feeding port 23 by sucking the material from an air discharging port 24 by vacuum under a condition that the air feeding and discharging port 17 is being opened. Subsequently, nitrogen is flowed into the hopper 12 through a nitrogen gas feeding pipe 10 by opening the air feeding and discharging port 17 in order to remove the air containing oxygen, which is remaining in the hopper 12, and, then, said air feeding and discharging port is closed after the inside of the hopper is replaced by the nitrogen perfectly. Air tries to flow into the system from sealing sections 25-28 and deteriorate molten resin by oxiding it upon vacuum feeding, however, the evacuation is effected under introducing atmosphere from the air feeding and discharging port, therefore, the air will never flow into the system. |
