There are many factors affecting the self-adhesive film, there are two main points: first, the crystallinity of PE material, the lower the crystallinity, the better the adhesion, the higher the crystallinity, the worse the adhesion. The degree of crystallinity reflects the density of PE material from another angle. Second, the flexural modulus of PE material is related to the flexural modulus, which represents the degree of softness of PE material. The lower the flexural modulus, the softer the PE protective film, and the easier the low molecular weight of PE is to immerse in the surface of the object, and the stronger the bond is.