Under the effect of corona treatment, the surface of the plastic PE protective film will be activated, and then, it will increase on the surface. With corona treatment, the surface wet tension of the PE protective film will reach 52~56mN/m or even higher. The surface wet tension of the corona treatment PE protective film has a great relationship with the voltage applied to the electrode or the distance between the electrode and the corona treatment roller.
However, the corona treatment should be moderate, not to say that the higher the corona treatment, the better. It is worth noting here that the PE protective film and the corona treatment roller should be taken to avoid air trapping. If air is trapped between them, it will actually be to a large extent. It may directly cause the reverse side of the protective film to be corona treated.
Immediately afterwards, in terms of the consequences caused by the corona on the back of the black PE protective film, it actually includes the anti-sticking phenomenon that may produce ink printing, and in another aspect, it actually refers to the aluminum plating At that time, the transfer of the aluminum-plated layer will occur. Therefore, the transfer of the glued layer will occur when the glue is applied.
The main measure to prevent corona on the reverse side of the PE protective film is to adjust the pressure of the rubber pressing roller before the corona treatment roller, and, in terms of the pressure at both ends of the pressing roller, it must be consistent and The pressure must also be appropriate.
In addition, in terms of the corona roller and the pinch roller, it must be noted that strict dynamic and static balance tests must be carried out, and the radial runout requirements must also be less than 0.05 mm. It is to ensure that the PE protective film can enter the corona roller smoothly, and then, it can prevent air from being trapped. In this way, for the PE protective film, the phenomenon of reverse corona can be avoided.