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Fracture analysis and preventive measures of injection molding machine screw

The fracture of the screw of the injection molding machine is also related to temperature, but it is rare. Most of them are due to the poor toughness of the material of the screw itself, or the operation time is long, and the screw needs to be refurbished.

The original roughness, such as the raw material with glass fiber, is the most waste screw and machine. This raw material has poor fluidity and requires a fast shooting speed. If it is not well controlled, the rocket head and the reverse finger ring will be broken in the light case, and the broken screw will be multi-section in the severe case. The fracture of the screw can be prevented. During the use of raw material addition, if the shutdown exceeds 3 minutes, the raw material in the material tube should be cleaned when the machine is turned on. It is best to use PP with high viscosity to clean the screw to prevent the decomposed raw material from wrapping the screw and the rocket head.

When cleaning, the speed is reduced so that the raw material is fully melted when heated and rotated. Cleaning the screw is better for pin-point molds to prevent the glue path from sticking to the static template and using hot materials for production when the machine is turned on.

When the work order is full, the machine is stopped. The workload is enough. Clean the screw immediately after the shutdown to discharge all the residual raw materials of the screw. When using PP or cleaning the raw materials of the screw.

Process problems, back pressure and screw breakage are also related. If the back pressure is too large, the screw back force will increase when adding materials, which can also cause the screw to break.

The injection end point cannot be zero, especially when the injection is carried out with a high-speed injection machine accumulator, which is easy to damage the rocket head. The injection residual volume needs to be controlled well. Remember, the most critical thing is that the holding time must be adjusted to zero during manual injection.

The molding temperature should be controlled well. When starting the machine, pay attention to loosening and then shooting, because when there is no loosening, the rocket head is wrapped with raw materials. If the material is washed or shot directly, it can directly cause the rocket head to break and the reverse ring to rupture. Remember to loosen and then shoot, so that the raw materials of the rocket head are separated from the rocket head. Remember that no matter what raw materials are used, the machine should not be stopped, and all the residual raw materials must be discharged to prepare for the next production.