Weld line
Causes:
1. The product design is unreasonable.
2. The injection speed is too slow.
3. Injection pressure is too low.
4. The injection time is too short.
5. The mold surface temperature is too low.
6. Insufficient exhaust.
7. The gate position is unreasonable.
8. The melt temperature is too low.

Solutions:

1. Increase the material temperature.
2. Improve injection speed.
3. Increase the mold temperature.
4. Increase exhaust.
5. Increase packing and holding pressure.
6. Increase the time of packing and holding pressure.
8. Reduce clamping force.
9. Change the size or position of the gate.
10. Adjust the proper holding pressure conversion position or holding pressure conversion method.