1. Check the gap between the stretch rod and the bottom mold, and verify it with random tooling.
2.Whether the bottom temperature of the bottle is too high.
3. The pre-blowing flow is too large.
4. The pre-blowing pressure is too high.
5. The pre-blowing time is too early.
6. The pre-blowing time is too long.
7. The heating temperature is not suitable.
8. Check whether the stretching rod is bent.
9. Check whether the preform is eccentric.