Peelable protective film is a kind of plastic film which has been pre-coated with adhesive on the back by cold pressing. It is directly compounded with the coated plate through a pair of composite rollers at room temperature. The film is a transparent,
thin plastic protective layer which can be peeled off after finished products. The bonding of strippable protective film and steel strip is a solvent-free composite process. This process does not have the problem of exhaust gas emission. It does not
need a huge and complex heating blast exhaust gas treatment device. The equipment is simple, the raw material is saved, the energy is reduced, and the maintenance cost is low, so the benefit is remarkable. Peelable membrane equipment covers a large
area, and the film layer is liable to damage the coating when peeling. However, due to its mature technology, simple operation and abundant material sources, it is still the preferred protection mode for most color coating plants.
Wax coating is another construction form of peelable protective layer. The peelable protective layer and wax layer are complementary in function. Peelable film can protect the surface of coated plate from damage caused by abnormal factors such as transportation, environment, shear and simple bending. But for the color coated sheet after roll forming, the strippable film is a little weak. During the cold bending process, the roll is easy to damage the protective film because of the pressure applied on the surface of the coated sheet. Especially when the shape of the cross section of the formed product is complex, because the linear velocity and deformation of each part of the cross section are different, the protective film is easy to be damaged. The film is more likely to be torn. At this time, if the wax coating is used instead, not only the above situation will not occur, but also a lubrication film can be formed between the surface of the color coating plate and the roller. Wax spraying equipment occupies a small area, and the wax layer has no damage to the coating surface. However, the spraying temperature is difficult to control, especially when used in northern areas, because the air temperature is low, it is easy to cause spraying difficulties due to solidification. And before each use, the nozzle must be cleaned. Because the wax is solidified at room temperature, it is difficult to clean the wax spraying mechanism.