Many people know that food aluminum foil packaging bags will leak more or less. Therefore, many friends will wonder what causes the food aluminum foil packaging bags to leak. Reasons for air leakage of food aluminum foil packaging bags 1. Bacterial reproduction in food aluminum foil packaging bags often produces gas, which is one of the reasons for food aluminum foil packaging bags to expand. Therefore, the product must be thoroughly sterilized before leaving the factory. The second reason for the leakage of food aluminum foil packaging bags is the tightness of food aluminum foil packaging bags. After the food is bagged, the last process is to heat-press the packaging bag, and the quality of this process will directly affect the sealing performance of the food aluminum foil packaging bag. If the final edge is not tightly sealed, the food aluminum foil packaging bag will leak air, and the air will penetrate into the vacuum packaging bag from the leaking part of the food aluminum foil packaging bag. This is another cause of food bag swelling. If the food bag leaks due to the sealing performance of the food aluminum foil packaging bag, the packaging quality can be detected and controlled in time by means of testing. It can be tested with a seal tester. If the food aluminum foil packaging bag is not well sealed, air bubbles can be observed to leak from the sealing edge of the food aluminum foil packaging bag during the test. The test results can help quality control personnel to adjust production parameters in a timely manner, so as to strictly control the safety of ex-factory food. Composite packaging bag, plastic packaging bag