Since the cover film PI smooth surface, combined with the poor PP, may be present during the uncovering and covering with a PP film delamination, leading to the appearance of white.
Because the cover film PI surface is smooth, and PP binding force difference, there may be PP and covering film layering phenomenon in the process of exposing, resulting in white appearance.
Due to the smooth surface of PI and poor binding force between PI and PP, there may be delamination of PP and PP during the uncovering process, resulting in white appearance.<br>