What to do if there is excessive friction between the blower's bubble tube and the herringbone splint?

During the blowing process, the friction between bubble tube and the herringbone splint is too much, which is a headache for many operators. The problem not only affects product quality, but also reduces productivity and increases costs. Below, we take a closer look at the problem and its solutions.

When there is too much friction between the bubble tube and the herringbone splint, the stability of the film bubble is affected first. Too much friction causes the bubbles to oscillate abnormally during operation, making it impossible for them to pass through the herringbone splint area. It's like when a person walks, their feet are constantly pulled, causing their gait to falter. This unstable bubble results uneven film thickness, too thick or too thin an area. This uneven film can easily lead to inconsistent strength in subsequent applications, such as in packaging bags. In the process of use, it is easy to appear weak links, affecting product performance. From a production efficiency perspective, bubble instability forces operators to frequently adjust equipment parameters and may even suspend production to address bubble anomalies. This inevitably wastes a lot of time, reduces output per unit of time and increases production costs. In addition, the bubble flow is not good, will lead to excessive or uneven film tensile process, further affect product quality, may lead to scrap and waste of raw materials.

Adjust the Herringbone Clamp Angle
Increasing the herringbone clamp angle is a relatively straightforward and effective solution. Increasing clamp angle can reduce the contact area between the bubble and the clamp. This is analogous to the contact area between the object and the ground: when tilted, the contact area decreases. In the case of bubbles and fixtures, the smaller contact area, the less friction. In general, without affecting quality of the membranes, try increasing the clamp angle by 5°-10° and observing the properties of the bubbles. For example, if the original angle is 30 degrees, it can be adjusted to 35°-40°. During the adjustment process, the stability of the bubble through the film is closely monitored, and the quality of the film is affected. It is important to note that the angle should not be too large, otherwise it will lead to poor folding of the film, affecting the smooth processing of follow-up. The appropriate herringbone angle will depend on the type of blower and the film specification produced. This requires operators to explore and adjust to actual production conditions.
Improved contact between bubbles and the herringbone splint
It is also possible to apply the right amount of lubricant to the surface of the bubble. Lubricant forms a lubricating film between the bubble and the herringbone splint, similar to lubricant between mechanical parts, reducing friction coefficient between them. Common lubricants include silicone oil and paraffin. When applying lubricating oil, use professional spray equipment and spread the lubricating oil evenly over the bubble surface. However, be careful how much lube you use. Too little may not provide significant lubrication, and too much may contaminate the film and affect subsequent processing properties, such as printing and laminating. The surface of the herringbone splint can also be treated to improve its finish. For example, polishing can be used to create a smoother surface and reduce friction as bubbles pass through. Some manufacturers polish the herringbone splint to mirror finish, greatly reduce friction between bubble and splint, effectively improve bubble performance.
Optimizing Production Process Parameters

The problem of excessive friction can also be alleviated to a certain extent by reducing the explosion rate appropriately. Blowout ratio is the ratio of bubble diameter to die diameter after blowout. When the explosion rate is high, the bubble wall is relatively thin and friction is more likely when it comes into contact with the splint. Reducing bubble bursting rate can thicken bubble wall, enhance the strength and stability of bubble wall, and reduce friction induced oscillation. For example, if the original blowing ratio is 3:1, try to reduce it to 2.5:1 or 2:1 and then look at bubble performance and film quality. However, reducing the blowout ratio may affect the transverse tensile strength and other properties of the film, so it must be adjusted while ensuring the quality of the film. Adjusting the pull speed also affects friction between the film bubble and the herringbone splints. If pulled out too quickly, the film bubble tension at the herringbone splint increases, increasing friction. A proper reduction in the pull out speed can make the film bubble pass through the herringbone splints more smoothly and reduce friction caused by the speed too fast. However, the pulling speed must not be too slow, otherwise it will affect productivity. Finding the suitable balance is crucial.

Excessive friction between the blowpipe and the herringbone splints is an important problem that requires attention. By adjusting the angle of the herringbone splint angle, improving contact conditions and optimizing production process parameters, this problem can be effectively solved and the quality and efficiency of blown film production can be improved. In practice, operators should apply these methods flexibly according to specific situation, constantly explore and learn lessons to ensure smooth production of the film.