Reasons for Uneven Shrinkage of Steam Shrink Tunnel

The problem of uneven shrinkage in steam shrink tunnels may be caused by a variety of factors, including temperature settings, conveying speed, air volume and direction, and characteristics of the product and packaging film.

details as follows:

1.Temperature setting

Make sure the temperature is suitable for the type of material used. For example, POF film is suitable for use at a temperature of 150 to 180 degrees, PE film is around 170 degrees, PVC80 is around 80 degrees, and PET is around 100 degrees.

2. Conveying speed

Adjust the conveying speed according to product type and packaging needs to achieve the best shrinkage effect.

3. Air volume and direction

Ensure that the air volume is sufficient and the air direction is adjusted appropriately to heat the product evenly and avoid uneven shrinkage due to uneven heating.

4. Characteristics of products and packaging films

Consider factors such as the size, shape of the product and the thickness of the packaging film to select the appropriate packaging film and ensure that its quality meets the requirements.

5. Mechanical failure

Check whether the thermometer and thermocouple are working properly and whether the heat sealing pressure is uniform.

In addition, for all-inclusive POF films, some small holes need to be drilled on the surface of the shrink film to discharge the gas in the film during shrinkage and avoid expansion. By adjusting these factors, the shrinking effect of the steam shrink tunnel can be significantly improved, ensuring more uniform shrinkage.