When we use hot melt adhesive film, we often encounter […]
When we use hot melt adhesive film, we often encounter some problems. For example, after hot melt adhesive film is hot-pressed, air bubbles are generated at the adhesive layer. The air bubbles remain between the adherend and the adhesive layer because the adhesive layer cannot be removed. between.
On the one hand, the remaining air bubbles will affect the aesthetics of the surface of the material, 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 draw our attention.
So, how can we prevent the hot melt adhesive film from generating bubbles during hot pressing?
First of all, we must check whether the hot melt adhesive film contains too much moisture before using the hot melt adhesive film. If the surface of the hot melt adhesive film contains too much moisture, water vapor will be generated during hot pressing. When the water vapor cannot be removed At that time, bubbles will be generated. Therefore, under normal circumstances, we should also pay attention when storing hot melt adhesive films. The air humidity in the storage area should not be too high, and good ventilation conditions must 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 rubber layer during hot pressing, we should try to use a roller-type hot pressing method, which can effectively discharge the air in the rubber layer. If there is no roller-type equipment, when using the flat-plate hot pressing method, we should adopt the method of stepwise pressurization, which can also effectively discharge the air and reduce the chance of air bubbles.