Reasons and solutions for common problems of PET preform molds

The preform mold manufacturer will explain the common problems and solutions of PET preform molds to everyone, hoping to be helpful and for reference only.

Phenomenon 1: Bending of preform after demolding

Reason: Eccentricity of the sprue hole and uneven cooling can cause the preform to bend after demolding.

Solution: When this situation occurs, some measures need to be taken. When the sprue hole is eccentric, the mold can be corrected; In addition, reducing the holding pressure, increasing the injection rate, extending the cooling, cleaning the waterway, and increasing the cooling water pressure and volume can all solve this bending phenomenon.

Phenomenon 2: The bottle body is not fully blown in the vertical direction

Reason: When such a situation occurs, it may be caused by insufficient temperature control of some preforms, cold blocks in some preforms, insufficient air pressure and volume, poor exhaust of the blowing mold, high blowing mold temperature, thin preform wall, and insufficient longitudinal stretching ratio of the bottle.

Solution: Adjust the temperature of the PET preform, do not touch the heated preform and check whether the cold hard block has been touched, increase the gas storage pressure and volume, increase exhaust, add cooling water to the blowing mold, correct the mold, and increase the longitudinal stretching ratio can all solve this problem.

Phenomenon 3: Poor vertical bearing capacity of the bottle

Reason: Uneven wall thickness, high heating temperature of the preform, and poor bottle shape can lead to poor vertical bearing capacity of the bottle.

Solution: To solve such problems, it is necessary to improve the uniform thickness of the bottle wall, form at low temperature and high pressure as much as possible, and improve the bottle shape design.

When problems arise, customers who use preform molds should not worry. They can first identify the root cause based on the problem and then solve it accordingly. The above three situations should have corresponding solutions, hoping to be helpful to customers who use preform molds.