When pasting waterproof and breathable film, bubbles are sometimes found on the surface, and bubbles become larger and larger, forming shadows. Shadows will affect the aesthetics of the object and make it inconvenient to use. How are shadows created?
The first is temperature. Due to the action of air bubbles, it is supported by air bubbles at 80℃, which means that the protective film begins to crack slowly at high temperature. If the adhesive of waterproof and breathable film is not good in heat resistance or binding force, it is easy to appear residual glue or shadow around its bubbles. Usually, where shadows appear is where bubbles form.
Another reason is that this usually happens with waterproof, breathable membranes that contain emulsifiers. When the emulsifier moves, it creates a shadow. The surfactant will act as an external plasticizer to make the film soft and elastic. If the plasticizer is evenly distributed during the coating process, the effect is better. However, due to the surface activity of surfactants, molecules migrate from the bulk phase to surface aggregation and tend to aggregate at the membrane-air interface, thus forming shadows.
The longer the time goes by, the larger the contact surface between the ordinary bubbles and the air, the higher the probability of forming a shadow. Therefore, please try to prevent the formation of small bubbles, use good quality waterproof breathable film, so as to delay the appearance of dark shadows.