Food packaging bags often experience curling, unevenness, and deformation after packaging products. What causes these phenomena? How can bag manufacturers avoid this situation? Many food manufacturers have likely encountered this issue to some extent: after packaging products in plastic food bags, the packaging surface curls, the bag twists and deforms, and the packaging becomes uneven. What are the main causes of these problems, and how can we solve them? Let's analyze the main reasons for curling and deformation of food packaging bags:

1. The surface substrate film has poor heat resistance, causing the edges to curl up when exposed to high temperatures.

2. Improper tension matching control of the composite substrate during the lamination process leads to residual stress after curing and setting, especially when the composite film is thinner.

3. Inconsistent thickness of the composite film.

4. Insufficient cooling; the temperature has not reached the setting temperature.

5. Insufficient curing time.

6. The trajectory of the composite film is not straight in the longitudinal heat-sealing section.

7. The heat sealing temperature is too high or the heat sealing time is too long.