Sealing film misalignment is usually caused by the following factors:

1. Improper Film Roll Installation

This is one of the most common causes. If the film roll is not installed centered on the shaft, or if it wobbles after installation, the film will gradually shift during operation. When installing the film roll, ensure it fits snugly against the shaft and rotates smoothly without wobbling.

2. Fixing Clamps Too Tight or Too Loose

If the fixing clamps (butterfly clamps) for the sealing film are too tight, they increase rotation resistance, potentially causing the film to jam or stretch and deform. If too loose, the film roll will wobble, also leading to misalignment. The correct tightness allows the film roll to rotate gently by hand — with some resistance but smooth movement.

3. Unbalanced Tension

Improper tension adjustment along the film path, resulting in uneven pull on the left and right sides, can cause the film to shift to one side during operation. Adjust the tension control rods or springs to keep the film flat without slack.

4. Photoelectric Eye (Registration Sensor) Issues

For automatic sealing machines, the photoelectric eye detects registration marks or positioning indicators on the film. If the sensor is dirty, mispositioned, or has incorrect sensitivity settings, it can lead to inaccurate cutting and sealing positions, resulting in skewed patterns.

5. Excessive Heat Sealing Temperature

Temperatures that are too high can cause uneven shrinkage of the film, leading to warping or skewing. This is especially true for multi-layer composite films, where excessive heat can cause different layers to shrink at different rates, resulting in distortion.

6. Roller Problems

During operation, if certain rollers rotate unevenly, have dirty surfaces, or are coated with adhesive residue, they can affect the smooth movement of the film and cause misalignment.

Leadtra Packaging — Focused on sealing technology, ensuring every seal is perfectly aligned. If you encounter difficulties adjusting your sealing film, or need sealing film products with more stable quality and smoother operation, feel free to contact Leadtra Packaging. We're always here to provide technical support.