Views: 0 Author: Site Editor Publish Time: 2022-08-27 Origin: Site
In the mold injection molding industry, trapped air is one of the frequently encountered injection defects. When the injection molded parts have trapped air problems, they usually appear insufficiently filled or scorched, whitish, and coarse air-entrapped lines are generated. In actual production, if there is a problem of trapped air in the injection molded parts of PP material, if effective exhaust measures are not taken, it is difficult to solve the problem by adjusting the machine, either insufficient filling or burning or whitening.
When the two streams are fused, and the gas mixed in the middle cannot be discharged, it will cause injection defects such as lack of gas, scorching of gas, and gas streaks. The pictures below show the lack of vadose material, the scorch of vadose gas and the vadose gas pattern.
2: Air trapped at the end of the deep rib stream
After the parting surface of the mold has been sealed by the rubber compound, when the material flow is still flowing in the vertical direction to the parting surface, the gas can no longer be discharged from the parting surface, which will cause injection defects such as trapped gas, lack of material, trapped gas and scorch.
3: Poor exhaust on the parting surface
Poor parting surface exhaust is the most common injection molding defect in some companies that do not pay attention to exhaust. The parting surface itself is the place where the exhaust groove is easy to open, but the gas is not completely discharged from the parting surface, causing trapped air to burn. This is mainly because the overall exhaust of the mold is not sufficient, and a large amount of gas is simultaneously compressed to a certain caused by the location.
It is impossible to completely avoid trapped air in the injection molding industry, so in the development stage of new products, the phenomenon of air entrapment should be avoided through mold flow analysis; strengthening the exhaust capacity of the mold can greatly reduce the resistance caused by air pressure, which is not conducive to the solution of the central thin film. Difficulty filling the wall can be of great help.