heat shrinkable film is widely used in the outer packaging of various products such as food, medicine, sterilized tableware, cultural and sports supplies, craft gifts, printed matter, hardware and plastic products, telephones, electronic appliances, etc., especially in the combined (bundled) packaging of irregular articles or commodities, which can not only meet the functions of moisture and dust prevention, touch-stealing prevention and transparent display of commodities. But also can increase that attractiveness of product appearance, and can also be used for replace various paper boxes, which not only saves the package cost, but also conforms to the packaging trend. Shrinkage films (bags) can be processed into special-shaped bags such as flat pocket, arc-shaped bags, trapezoidal bags, three-dimensional bags and the like.