The phenomenon that the two ends are warped mostly occurs on the aluminum foil film. The main performance is that the protective films at both ends are raised. The main reason is that during the compounding process of the aluminum foil film, the tension between the BOPP and PET layers is inconsistent, and the tension of the BOPP layer is too large. After the compounding is completed, the BOPP layer retracts due to the tension and temperature changes, resulting in lifting. It is recommended not to use this kind of film in areas with high ambient temperature and high wind and sand.