There are many materials for food packaging bags, and the uses of each material are different. The main materials for food packaging are: PVDC (polyvinylidene chloride), PE (polyethylene), PA (nylon), EVOH ( Ethylene/vinyl alcohol copolymer), aluminized film (aluminum + PE) and other materials have different properties and uses. Generally, food packaging bags are not made of a single material. Generally, the red casing of multi-layer composite ham sausage is a single material of PVDC. But the packaging bag is not a single material. Generally, the inner layer is PE, the outer layer is PA, and some may use aluminized film such as EVOH or PVDC in the middle. Reason: PE has better heat sealing performance, that is, it is easy to seal PA, which has better printing performance. When used in the outer layer, it can print beautiful pictures. PVDC and EVOH have better barrier properties and prevent oxidation. The aluminized film has good light blocking properties, which is suitable for products that are difficult to see light. The specific material uses and compounding issues are more professional, so I will not introduce them one by one. If you want to know more about food packaging bags: www.yltpacking.com Customized food packaging bags