The coating edge surface is larger and evaporates faster, so the temperature drops, the surface tension rises, and the nearby coating spreads to it automatically, thus forming a phenomenon of edge thickening.
Foggy phenomena:
The foggy phenomenon is that the protective film is blurred, opaque and shaded. For oily adhesives, one is that the ambient humidity is relatively high, the glue is mixed with more water vapor, and the glue layer becomes foggy and white during the drying process; the other is that if the protective film after gluing passes through the high temperature channel, the temperature setting is not appropriate, it may also produce fogging phenomenon.
Bernal's swirl nest:
During the drying process, with the evaporation of the solvent, the surface concentration increases, the temperature decreases, and the surface tension increases. Because of the difference in surface tension between the surface and the bottom layer, there is a driving force that causes the glue to move from the bottom layer to the upper layer, which leads to local eddies and the formation of the so-called Benar swirl chamber. In the paint industry, if the paint leveling is not good, this phenomenon is more common in the film after drying, will leave a bumpy orange peel.