Food-grade plastic bags are generally divided into ordinary food packaging bags, vacuum food packaging bags, inflatable food packaging bags, boiled food packaging bags, retort food packaging bags and functional food packaging bags. The materials are also diverse, and common food Grade plastic bag materials include: PE (polyethylene), aluminum foil, nylon and composite materials, etc. In order to ensure that food is fresh and free from rot, food-grade plastic bags have some common characteristics regardless of category and material. First, they are required to completely block organic solvents, grease, gases, water vapor, etc.; second, they have excellent permeability resistance, It is moisture-proof, cold-resistant, heat-resistant, light-proof and insulating, and has a beautiful appearance; third, it is easy to form and has low processing cost; fourth, it has good strength, and the strength performance per unit weight of the plastic packaging bag is high. Impact resistant and easy to modify.