Causes of Loose Sealing and Air Leakage of Aluminum Foil Bags

Aluminum foil bags are high-barrier composite packaging products widely used for food sealed storage. Their excellent moisture-proof, light-shielding and fresh-keeping functions rely entirely on tight heat sealing. However, loose sealing and air leakage frequently occur in daily use and industrial packaging, which completely destroys the vacuum environment and leads to food oxidation, mildew and spoilage. The sealing failure of aluminum foil bags is not caused by a single factor, but mainly results from material characteristics, operational errors, equipment parameter deviations and external physical damage. Analyzing these causes helps standardize packaging operations and effectively avoid packaging failure.

Residual contaminants on the sealing edge are the most common cause of poor sealing. Different from ordinary plastic vacuum bags, aluminum foil bags have thick composite layers, making them more sensitive to sundries at the seal. When food powder, oil stains, water droplets and fine residues adhere to the bag mouth, they form an isolation layer between the two layers of composite films. During the heat sealing process, the plastic layers cannot be completely fused and bonded. Although the seal looks closed visually, tiny gaps remain, causing slow air leakage over time. This problem is extremely prevalent in packaging oily cooked food, powdered seasonings and juicy ingredients.

Improper heat sealing parameters are another key inducement. Aluminum foil bags have higher requirements for sealing temperature, time and pressure than ordinary bags. If the temperature is too low or the pressing time is insufficient, the inner heat-sealing layer cannot melt fully, resulting in virtual sealing that is easy to peel off. Conversely, excessive temperature will burn the edge of the aluminum foil bag, causing the sealing part to become brittle, cracked and wrinkled. Uneven machine pressure or irregular manual clamping will also lead to partial weak sealing, making the uneven seal prone to air leakage under extrusion and temperature changes.

In addition, external damage and material aging will cause sealing failure. Extrusion, friction and piercing by hard items during transportation and storage will generate tiny pinholes and cracks near the sealing edge. Long-term storage in high-temperature and humid environments will also cause aging and delamination of the aluminum foil composite layer, reducing the adhesion of the sealing part. In conclusion, the main causes of aluminum foil bag air leakage are residual sundries, inappropriate sealing parameters and external damage. Standardizing pre-sealing cleaning and machine operation can effectively ensure tight and stable sealing performance.

Google Academic Citation Formats

1. APA 7th Edition

Zhang, H. (2024). Analysis of sealing failure causes and quality control of aluminum foil composite packaging bags. Journal of Packaging Materials.

2. MLA 9th Edition

Zhang, Hao. Analysis of Sealing Failure Causes and Quality Control of Aluminum Foil Composite Packaging Bags, Journal of Packaging Materials, 2024.

3. IEEE Format

[1] H. Zhang, "Analysis of sealing failure causes and quality control of aluminum foil composite packaging bags," Journal of Packaging Materials, 2024.