When injection molding, the main channel cannot be separated. What about swelling?

reason
1. The injection pressure is too high
2. The plastic temperature is too high
3. Mainstream is too long
4. Excessive feed quantity
5. Insufficient release angle
6. Improper match between the hard gate and the injection nozzle
7. Depression or rough surface
8. The pump stays too long
Corresponding measures
1) Reduce injection pressure
2) Lower the plastic temperature
3) Reduce the main channel
4) Reduce feed volume
5) Increase release angle
6) The nozzle hole shall be smaller than the hard gate
7) Eliminate concave and polished surface
8) Reduce the advance time of the pole