The air trapping position in cavity and exhaust method
The air trapping in cavity is usually in the following places:
1. Thin-wall structure cavity, the end of melt flow;
2. The junction of two or more melts;
3. The last area where the melt in the cavity reaches;
4. The bottom of the blind hole of the mold cavity is mostly the end of a solid column in the part;
5. Reinforcing ribs of molded parts and the bottom of screw pillars;
6. Dead corners of complex mold cavities.
Exhaust method in injection mold include as following:
1. Parting surface (including venting slot);
2. The fitting surface of insert;
3. The fitting surface of the push rod or pipe with inner mold insert;
4. Exhaust from side core pulling mechanism;
5. Add a vent needle or insert to vent the air in the trapped area;
6. Breathable steel exhaust;
7. Air valve exhaust;
8. The mold is evacuated and exhausted.
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