Requirements for surface quality of aluminum foil bags for food

1. The surface shall be clean and flat, free of corrosion scar and bruise, and free of serious wrinkles and folds. It shall be soft, not easy to break when folding, and has good flexibility. The purchased aluminum foil shall be stored in a dry condition, and shall not be left for too long. It shall be used as early as possible. 2. The aluminum foil surface shall be clean, free of obvious yellow oil stains formed after the burning of lubricating oil, and free of oil smell. The aluminum foil surface shall reach Grade A or Grade B after the water brushing test. The surface tension shall be high, and shall reach above 72Mn/m. A simple method is to use distilled water for inspection. The distilled water should be completely soaked on the aluminum foil surface. If the aluminum foil surface is seriously greasy, it will affect the fastness of the aluminum foil and other materials, especially the peeling of the packaging bag after high-temperature cooking. 3. Oil stain and pinhole are the main detection indicators of the product. Pharmaceutical aluminum foil materials have high requirements on the physical, mechanical and chemical properties of aluminum foil. The number of pinholes in aluminum foil should be small. No matter how thick the aluminum foil is, the pinhole aperture should not be greater than 20um.