[China Aluminum Network] Sometimes our extruded products will always have air bubbles, but also from the skin, what is going on here? Xiao Lu arranged for some reasons for your reference:
1. Squeeze the barrel, the wear of the squeeze pad is poor, the size of the squeeze tube and the squeeze pad is not properly matched, and the difference in the diameter of the gasket used exceeds the allowable value;
2. The squeeze tube and the pressing pad are too dirty, with oil, moisture, graphite, etc.;
3. Lubricating oil contains water;
4. There are too many troughs on the surface of the ingot, too deep, or there are pores, blisters on the surface of the ingot, loose structure, oil stains, etc.;
5. When replacing the alloy, the inside of the barrel is not clean;
6. Extrusion barrel temperature and extrusion ingot temperature are too high;
7. Ingot temperature, size exceeds allowable negative deviation;
8. The ingot is too long, the filling is too fast, the temperature of the ingot is uneven, and the non-drum filling is caused, so the exhaust in the cylinder is incomplete, or the operation is not proper, and the exhaust process is not performed;
9. Improper design of die hole, improper cutting of residual material, diversion hole and diversion hole