The main purpose of conducting salt spray testing on Pet protective film is to simulate the transportation environment at sea. Sea freight has always been a relatively inexpensive transportation method, so it is also favored by many protective film manufacturers. However, sea freight generally takes a long time, and a transportation may take 1-2 months. The protective film material floats to the sea for a long time because the seawater contains salt, and the humid air at sea is afraid of chemical reactions after contact with the protective film, which may cause corrosion of the protective film. Therefore, as long as the protective film needs to be transported by ship, salt spray testing is required.