Common technical problems of blow molding machines

The blow molding process of the blow molding machine is a two-way stretching process. The chain is extended, oriented and arranged in both directions to improve the tensile, tensile, impact strength, and air tightness. In the production process, the stretching and inflation are well controlled. than to avoid quality problems.

The blow molding process can be divided into three processes: stretching, primary blowing, and secondary blowing. The three actions have a short time, but they must be well coordinated, especially in the stretching and primary blowing stages, which determine the overall distribution of the material. The final product is good or bad, so it is necessary to adjust the starting timing of stretching, the stretching speed, the starting and ending timing of pre-blowing.

The more common blow molding machine technical problems we made a summary

1. Thick on the top and thin on the bottom: delay the pre-blowing time or reduce the pre-blowing pressure to reduce the air flow.

2. Thicker at the bottom and thinner at the top: the opposite of the above.

3. There are wrinkles under the bottle neck: the pre-blowing is too late or the pre-blowing pressure is too low, or the billet is not cooled well here.

4. White bottom: the preform is too cold, overstretched, pre-blowing too early or pre-blowing pressure is too high.

5. There is a magnifying glass phenomenon at the bottom of the bottle: there is too much material at the bottom of the bottle, 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 bottom temperature is too high, the cooling at the gate is not good, the pre-blowing pressure is too low, and the flow rate is too small.

7. The whole bottle is cloudy: opaque, not enough cooling.

8. Local whitening: excessive stretching, the temperature here is too low, or the pre-blowing is too early, or the stretching rod is touched.

9. The eccentricity of the bottom of the bottle: it may be related to the temperature of the preform, stretching, pre-blowing, high-pressure blowing, etc. Reduce the temperature of the preform, speed up the stretching speed, check the gap between the tie rod head and the bottom mold, delay the pre-blowing, reduce the pre-blowing pressure, delay the high-pressure blowing, and check whether the preform is eccentric.