The protective film performs well in the middle after a period of use, but the wings are raised at both ends. The main reason for this phenomenon is that the protective film is stretched more during the pasting process with the protected profile. In the future, in the high temperature environment, there is an unnecessary retraction phenomenon. This problem occurs mostly in the products of southern customers. Therefore, PE protective film should pay attention to the influence of environmental temperature difference on the use of the product during the production process. Avoid unnecessary surface stretching.