Why does the screw of the injection molding machine lock up?

Update:30 Dec 2020

In the injection molding process, the screw of the injection molding machine is often stuck and does not rotate. Usually, if the screw protection device of the injection molding machine does not work, the operator should stop it immediately. In many cases, the screw of the injection molding machine can still rotate, but the speed is much slower. At the same time, there is a harsh metal grinding sound, and the current rises sharply.
There are probably several reasons for this situation:
1. The thermal expansion coefficient of the material used in the screw and barrel of the injection molding machine is too different. When heating, the feeding seat of the injection molding machine barrel is cooled, and if the screw is not cooled, it may lock up.
2. The design of the screw and barrel of the injection molding machine is unreasonable. It is easy to happen that the compression ratio of the screw design is too large, and the screw deforms during use.
3: The barrel temperature is too low, or the filter plate is blocked, causing the barrel pressure to rise sharply, causing the screw to deform.
4. The screw or barrel is deformed.
5. Foreign matter enters the barrel and jams the screw. If it is a ferrous metal foreign matter, it will cause great damage to the screw and the barrel.More about:screw barrel for Injection molding machine

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