Double acoustic membrane on laminate glass

[nikossyg]

The salesman at the glass company that I went today suggested that it's better with 2 pvb acoustic membranes for one laminate glass. Does that make much of a difference?

[gullfo]

generally speaking, you want each layer in an isolating window to have a mass similar to the surface mass surrounding it. so if you have a wall with 2x 16mm gwb that is about 20kg/m2. so you would want the interior glass to match or slightly exceed that. so using laminated glass - you get the mass fairly easily, and the laminate helps to damp the resonances. if 12mm thick glass was required, then consider using 3x 4mm with 2 laminates, or 2x 6mm with 1 laminate layer, to achieve that. repeat the math for the other side.
if both sides needed 12mm, then consider 1 side with the 3x laminated panes, and the other 2x, as this changes their resonant characteristics and can reduce coincident frequencies which can reduce the isolation.

[nikossyg]

Τhank you very much for the response!
As far I understood, he suggested 6mm+2 pvb membranes+6mm . ( for the 12mm laminate glass that I want)
Is that even possible?

[gullfo]

i guess it depends on the thickness of the polyvinyl butyral (PVB) materials, maybe he meant 0.2mm pvb? but it seems ok.

[nikossyg]

He said both pvb membranes will be 0.76mm total thickness.

[gullfo]

ok