When using the hot melt adhesive film, we often encounter some problems. For example, air bubbles are generated at the adhesive layer after the hot melt adhesive film is hot pressed. Because the air bubble cannot be excluded from the adhesive layer, the air bubbles remain between the adherend and the adhesive layer. Between.
On the one hand, the residual air bubbles will affect the aesthetics of the material surface, and on the other hand, it will also reduce the bonding area and reduce the bonding strength. Therefore, when the bubble problem occurs after the hot pressing compound, we need to pay attention to it.
So, how to prevent the hot melt adhesive film from generating bubbles?
First of all, we should check whether the hot melt adhesive film contains too much water before using the hot melt adhesive film. If the surface of the hot melt adhesive film contains too much water, water vapour will be generated during hot pressing. When the water vapour cannot be excluded, bubbles are formed. Therefore, under normal circumstances, we should also pay attention when storing the hot melt adhesive film, the air humidity in the storage place should not be too high, and good ventilation conditions should be maintained so as to prevent the moisture content of the hot melt adhesive film from being too high.
In order to better discharge the air in the adhesive layer during hot pressing, we should try to use a roller-type hot pressing method, which can effectively discharge the air in the adhesive layer. If there is no roller-type equipment, when using the flat-plate hot-pressing method, we should adopt the method of segmented pressurization, which can also effectively discharge the air and reduce the chance of air bubbles.