Phenomenon 1: Bottle mouth of bottle blowing mold swells, and bottle blowing runs out

Reason: As the temperature of the surrounding space gradually increases, the cooling effect of the air flow passing through the oven is reduced. As a result, the temperature of the core rod rises and then passes to the thread area.

Treatment method: external cooling can be used to control the temperature of the thread area and the core rod of the preform when passing through the oven; adjust the position of the cooling plate so that it can better protect the thread area of the preform. In addition, a well-planned cooling plate may be a better countermeasure.

Phenomenon 2: Bottom of blow mold is broken

Reason: The temperature at the bottom of the preform is relatively low, and a micro-crack is formed when the stretching rod is pressed against the bottom of the mold.

Treatment method: The best way to do this is to make the end of the preform neither too cold nor too hot between stretching and breaking. In addition, the gap between the stretching rod and the bottom of the mold is also critical. Only by using the necessary large gaps can the door be positioned.

Phenomenon 3: Transition

Cause: The problematic cavity may be caused by a lack of air blow. If the temperature of the preform during blowing is lower and the film bubble blows more slowly, the problem will be more obvious. The lighter bottom together means that the material has reached its natural stretch limit before the entire container is formed.

Treatment method: make sure that all the ventilation holes on the bottle blowing mold are not blocked; ensure that the blowing can be completed in a short time, otherwise, the PET material will be cooled when blowing; check the working conditions of the road valve to Ensure accurate positioning during blow.

Phenomenon 4: neck twists

Reason: This problem is usually caused by mechanical operation, and the neck material is too thick to cause deformation after clamping.

Treatment method: The bottle neck is too thick, and the bottleneck will be distorted when it is touched by the mold. In addition, the alignment of the conveying arm and the blowing center is also a cause of this problem.

Phenomenon 5: The screw part of the bottle mouth is damaged

Reason: The preform is fed into the mold cavity by the conveying arm. When clamping, the thread side must be stressed. When the position of the conveying arm is inaccurate, when it lifts the preform ring from above the mold, if the weather is cold, the core pressure is It will exert a compaction effect on the closed surface of the preform, and will not cause damage. Unfortunately, in hot climates, the exhaust of the threads is subject to tensile forces, because the preform is forced to be aligned by the blow core that is punched down.

Treatment method: Make sure that the adjustment of the conveying arm is accurate; also, the alignment of the mold in the core area is also related.