The most important food packaging is PP and PE, that is, polypropylene and polyethylene plastics. There are two types of safety performance that can satisfy food packaging. The issue of bisphenol A has been vigorously debated on the issue of child development. Some countries have banned the use of bisphenol A in food packaging plastics. Compared with non-food packaging, PP and PE are free of plastic additives and do not release toxic substances during use. PE is softer and has poorer mechanical properties than PP, which means that the products include general supermarket shopping bags, plastic wrap, garbage bags and so on. PP is hard, anisotropic (it is easy to tear if there is a gap), good mechanical properties, and high temperature performance is better than PE, which means it is a bread bag. Generally according to the material structure, the inner layer is PE or CPP, the outer layer is PA, PET, the middle may be EVOH, or PVDC, etc., and some use aluminized film or aluminum foil. Aluminum foil bags, plastic bags Reason: PE and CPP have better heat sealing properties, that is, they are easy to seal. PA and PET have good printability and are used in the outer layer to print pictures. PVDC and EVOH have better barrier properties and prevent oxidation. Aluminized film and aluminum foil have good shading properties, which are suitable for products that are not easy to see light. Tea packaging bags and composite packaging bags have different properties and uses of various materials. General food packaging bags are not a single material, generally multi-layer composite. For dry and frozen goods, PET/PE is generally used. Like high-temperature cooking, nylon composite CPP, or other composites are generally used. The red casing of the ham is a single material PVDC. Candy and chocolate generally use transparent paper/PP, kraft paper/PE/Al/PE, Al/PE, etc. Vacuum packaging bags 1. The materials used in common food packaging bags are divided into six categories: 1. Material: BOPP/LLDPE two-layer composite characteristics: moisture-proof, cold-resistant, low-temperature heat sealing and strong tensile strength Uses: instant noodles, snacks, frozen snacks, powder Packaging, etc. 2. Material: BOPP/CPP two-layer composite Features: moisture-proof, oil-resistant, high transparency, good stiffness Uses: instant noodles, biscuits, candy, all kinds of light food 3. Material: BOPP/VMCPP composite Features: moisture-proof, oil-resistant, Oxygen barrier, shading, good stiffness Uses: all kinds of dry food, fried food, potato chips Snacks, tea 5. Material: PET/CPP two-layer composite Features: moisture-proof, oxygen barrier, fragrance preservation, high temperature resistance Moisture-proof, high-temperature resistance, easy to seal Uses: powder packaging, soy sauce, liquid, shampoo 2. Food packaging bag specifications: Different manufacturers have different requirements, maybe the same size products, some customers need to be looser and some want to be more compact , the size is customized, the customer needs to communicate with the manufacturer and then choose the most suitable specification. Customers choose general specifications, transparent vacuum bags and other products. .packaging bag