Zhejiang Ente Packaging New Material Co., Ltd. explains the reasons why transparent food bags may have quality problems. We are all familiar with food packaging bags, encountering various types in our daily lives. Of course, various factors can cause quality problems in transparent food bags during the production process.

1. Inappropriate Adhesive Selection.

The adhesive itself is dark in color; the adhesive lacks fluidity and flattening properties, failing to spread sufficiently on the base film.

2. Process Issues.

a. The inlet temperature of the drying tunnel is too high or there is no temperature gradient. Excessive inlet temperature and rapid drying cause the solvent on the surface of the adhesive layer to evaporate quickly, forming a skin. Then, when the heat penetrates deeper into the adhesive layer, the solvent beneath the skin vaporizes, breaking through the adhesive film to form ring-shaped structures like volcano vents, making the adhesive layer opaque.

b. Defects in the composite rubber roller or scraper, resulting in gaps in adhesion and opacity at certain points.

c. Too much dust in the ambient air, including dust in the hot air blown into the drying tunnel after adhesive application. This dust adheres to the adhesive layer and gets trapped between the two base films during lamination, creating numerous small dots and resulting in opacity.

d. Insufficient adhesive application, leaving gaps and small air bubbles, forming mottled or opaque patches. The amount of adhesive applied should be checked to ensure it is sufficient and even.

e. No spreading roller or an unclean spreading roller.

3. Problems with the base material itself, such as tension issues in the food packaging bag, or insufficient adhesive wetting of the packaging bag.

These issues require manufacturers to pay attention during production, strictly adhering to relevant industry standards and national laws and regulations at every stage of production. Only in this way can the pass rate of the produced packaging bags be improved, ensuring the health of users.