【 Flying Pigeon Union 】 Technical Tips | Uneven Thickness of Blowing Bottle Body? 3 adjustment techniques to quickly solve!

In bottle blowing production, uneven wall thickness of the bottle body is the most common problem of defective products, which not only affects the appearance and structural strength of the product, but also directly increases production costs.

Jiangsu Feige Youlian has been deeply involved in the industry for many years, adhering to the original intention of craftsmanship research and quality, focusing on the fields of blow molding, filling, and extrusion equipment, and providing one-stop solutions for customers in various industries with high output, low energy consumption, multiple adaptability, and low lossPETProduce a comprehensive solution that fully adapts to the production needs of scale, standardization, and intelligence. Our core competitiveness lies in our solid technological foundation, mature production line solutions, good market reputation, and reliable service system. In the future, Jiangsu Feige Youlian will continue to deepen technological innovation, optimize production plans, and create greater production value for customers. It is your high-quality and trusted choice for laying out PET blow molding and filling production and long-term cooperation.

Today's article teaches you how to quickly adjust from the three core dimensions of temperature, blowing, and stretching. With just three steps, it can be efficiently improved, and frontline operators can directly get started.

　　01

　　Partition adjustment of oven temperature

　　Improve unilateral/local thickness

Uneven heating of the preform is the primary cause of abnormal thickness of the bottle body.

　　01. Phenomenon

The bottle body is thicker or thinner on one side, or the upper and lower parts are poorly fixed.

　　02. Adjustment method

Observe the defective position of the bottle and adjust the corresponding oven temperature zone accordingly:

-Thick area of bottle body:Reduce the corresponding lamp power/temperatureReduce material accumulation

-Thin area of bottle body:Appropriately increase the heating temperatureMake the preform soften more fully and stretch more evenly

-Inconsistent thickness of upper and lower walls: Adjust the upper and lower temperature zones of the oven layer by layer to ensure balanced heating of the entire preform

　　03. Attention

Avoid excessive local temperature, prevent secondary defects such as whitening of the bottle wall, excessive stretching, perforation and bursting of the bottle.

　　02

　　

　　Optimize blowing parameters

　　Correct the overall wall thickness of the bottle body

Improper combination of pre blowing and high-pressure blowing can easily cause unevenness and disorderly wall thickness in the middle of the bottle body.

　　1

　　Pre blowing air

-Local accumulation of thick bottle body: slightly increase the pre blowing air pressure to evenly spread the bottle preform in advance

-Local thinning and excessive stretching: appropriately reduce the pre blowing pressure

-Fine tune the blowing delay to makeSimultaneous matching of stretching action and pre blowing actionTo avoid pulling before blowing and forming disorder

　　2

　　High pressure blowing

-The whole bottle is too thick and the molding is not full: increase the high-pressure air pressure or extend the holding time

-Ensure that the preform is completely adhered tightlymoldThe cavity has an overall uniform wall thickness and a standard full bottle shape

　　03

Adjust the speed and stroke of the stretching rod

Resolve longitudinal wall thickness deviation

The stretching action determines the material distribution of the bottle body from top to bottom, and is often used to improve uneven longitudinal wall thickness.

　　01. The upper part of the bottle body is thin and the lower part is thick

Accelerate the downward speed of the stretching rod to complete the axial stretching ahead of schedule.

　　02. The wall thickness at the junction of the bottle bottom and body exceeds the standard

Moderately increase the stroke of the stretching rod to ensure sufficient stretching at the bottom.

　　03. Supplement

Regularly check the operation status of the stretching rod, promptly correct and lubricate any jamming or deviation.

　　Quick troubleshooting tips

Debugging in the order of "temperature → blowing → stretching", from simple to complex, test the machine and observe the effect; If there are repeated thickness issues at the same fixed position, check for hardware problems such as mold exhaust and preform positioning.