Bubbles in Middle of Safety Laminated Glass of CNC-Shield® Polyvinyl Butyral PVB
Reason Possibility 1:
In the procedure of roller exhausting air, it’s too early to seal the edges of the pre-laminated glass, so the air can not be exhausted out completely in the second roller.
Adjust the speed and temperature in the pre-laminating procedure, make sure the pre-laminated glass is not sealed before the second roller exhausting air stage. Or adjust the speed of and temperature of the silicone rubber ring, to make sure the air is totally exhausted out.
Reason Possibility 2:
The Polyvinyl Butyral PVB interlayer film already absorbed too much moisture.
Check the moisture of the Polyvinyl Butyral PVB interlayer film, and the humidity of the laminating room and glass surface.
The plainness of the tempered glass is not good enough.
Choose good quality tempered glass, or use thicker Polyvinyl Butyral PVB interlayer film.