2, plastic film refers to the use of polyvinyl chloride, polyethylene, polypropylene, polystyrene and other resins made of film, used for packaging, as well as used as a laminating layer. Plastic packaging and plastic packaging products in the market accounted for an increasing share, especially composite plastic flexible packaging, has been widely used in food, medicine, chemicals and other fields, including food packaging accounted for the largest proportion, such as beverage packaging, frozen food packaging, steamed food packaging, fast food food packaging, etc., these products have brought great convenience to people's lives.