PET bottle preform blowing mold common problems and solutions
1. Thick and lower thin:
Delays the pre -blowing time, or reduce the pre -blowing pressure and reduce air flow.
2. Thick up and thin:
Pre -blowing time in advance, or increase pre -blowing pressure to increase air flow.
3. Wiring under the bottleneck:
Preform-blowing too late or pre -blowing pressure is too low, or the blank is not cooled here.
4.Black bottom:
The bottle blank is too cold; excessive stretching; pre -pre -blowing too early or pre -blowing too high.
5. Bottle bottom magnifying glass phenomenon:
There are too many bottle bottoms; the pre -blowing is too late, and the pre -blowing pressure is too low.
6. There are wrinkles in the bottom of the bottle:
The temperature at the bottom is too high (the cooling at the mouth is not good); the pre -blowing pressure is too low, and the flow is too small.
7. The entire bottle is turbid (opaque):
Cooling is not enough.
8. Local whitening:
Excessive stretching, the temperature here is too low, or the pre -blowing is too early, or the stretch rod is encountered.
9. Bottle bottom eccentric:
It may have something to do with the temperature, stretching, pre -blowing, and high pressure blowing.
Reduce the temperature of the bottle; speed up the stretching speed;
Check the gap between the tie rod head and the bottom mold;
Delays pre -blowing, reduce pre -blowing pressure;
Delays high pressure blowing; check whether the bottle blank is eccentric.