In the production process of PET preforms, the performance and condition of the mold directly affect the quality and production efficiency of the product. As a professional manufacturer in the field of preform molds, Heyan Mold is committed to providing customers with high-quality and efficient mold solutions. Below, we will share the reasons and solutions for several common problems with PET preform molds.
1, Bending of preform after demolding
Phenomenon description: The preform bends after demolding, affecting the shape and appearance of the finished bottle.
Cause analysis:
The eccentricity of the sprue hole causes uneven stress on the preform.
Uneven cooling, with some areas experiencing excessively high or low temperatures.
resolvent:
Correct the mold to ensure accurate positioning of the sprue holes and avoid eccentricity.
Adjust the cooling system to ensure even cooling of all parts of the preform. The customized cooling system provided by Heyan Mold can effectively solve the problem of uneven cooling.
2, The bottle body is not fully blown in the vertical direction
Phenomenon description: The bottle body is not fully blown in the vertical direction, resulting in dents or voids.
Cause analysis:
The temperature of some bottle preforms is too high, resulting in poor material fluidity.
There are cold lumps in the preform, which affect the blowing effect of the bottle.
Insufficient wind pressure and volume, insufficient blowing force.
Poor exhaust of the bottle blowing mold results in the inability to smoothly release internal gas.
The temperature of the bottle blowing mold is too high, causing excessive softening of the material.
The preform wall is too thin to withstand sufficient tensile force.
The insufficient longitudinal stretching ratio of the bottle results in insufficient height of the bottle body.
resolvent:
Adjust the preform temperature to ensure it is within the appropriate range.
Check and clean the cold blocks on the preform to ensure that it is clean and free of impurities.
Increase the gas storage pressure and volume, and enhance the blowing force.
Improve the exhaust design of the bottle blowing mold to ensure smooth gas discharge.
Reduce the temperature of the bottle blowing mold to avoid excessive softening of the material.
Revise the mold, increase the wall thickness of the preform, and improve its ability to withstand tensile forces.
Adjust the stretch ratio to ensure that the bottle can be fully blown in the vertical direction. The customized service of Heyan Mold can accurately adjust mold parameters according to customer needs, ensuring product quality.
3, Poor vertical bearing capacity of the bottle
Phenomenon description: The bottle has insufficient vertical load-bearing capacity and is prone to deformation or breakage.
Cause analysis:
Uneven thickness of the bottle wall leads to uneven stress distribution.
The heating temperature of the preform is too high, resulting in a decrease in material properties.
The bottle shape design is unreasonable, resulting in uneven force distribution.
resolvent:
Improve mold design to ensure uniform thickness of bottle walls. With advanced design concepts and manufacturing technology, Heyan Mold can provide customers with high-precision and high-quality mold products.
Reduce the heating temperature of the preform to ensure stable material properties.
Improve bottle shape design, optimize load-bearing structure, and enhance vertical load-bearing capacity.
Summary:
Encountering problems during the use of PET preform molds is not scary. The key is to identify the root cause of the problem and take corresponding measures to solve it. As a professional manufacturer of preform molds, Heyan Mold will provide you with comprehensive technical support and solutions to ensure the smooth progress of your production.
