What kind of material is for food packaging bag?
The food packaging bags are mainly made of PVDC (polyvinylidene chloride), PE (polyethylene), PP (polypropylene), PA (nylon), EVOH (ethylene/vinyl alcohol copolymer), aluminized film (aluminum + PE) and other major laminated film. The laminated film is produced by dividing the film and blowing the film.
The main components used in food packaging today are PP and PE, which are polypropylene and polyethylene plastic. Compared with the safety performance, both of these can meet the food packaging requirement. For now, there is no report on the issue of PP and PE products in the world. Polycarbonate used to be issue debate on the bisphenol A in children’s reproductive development, and some countries have banned the use of bisphenol A in food packaging plastics.
Compared with non-food packaging, PP and PE are plastic-free additives, and will not release toxic substances during use. Previous cling film was made of PVC, but because of its unsafe nature, it is now being replaced by PE cling film. PE’s softness and mechanical properties are worse than PP, which generally used as supermarket shopping bags, plastic wrap, garbage bags and so on. PP is hard, anisotropic (it is easy to tear when there is a norch), good mechanical properties, high temperature performance is better than PE, like bread bag.
Generally, according to the material structure, the inner layer is PE or CPP, the outer layer is PA, PET, intermediate may be EVOH, or PVDC, etc., and some are used for aluminized film or aluminum foil.
Reason: PE and CPP have better heat seal ability and are easy to seal. PA, PET has good printability and is used in the outer layer to print beautiful images. PVDC and EVOH have good barrier properties and prevent oxidation. Aluminized film, aluminum foil has good light-shielding properties, and is suitable for products that are not easy to see light.
Various materials have different properties and different uses. Generally, food packaging bags are not a single material, and are generally multi-layer laminated. Dry foods, generally used PET / PE. Like high temperature cooking, nylon laminated CPP is generally used, or other laminated packaging. The sausage using single material PVDC. Candy chocolate is generally made of transparent paper/PP, Kraft paper/PE/Al/PE, Al/PE, and the like.