Hi, everybody. I see quit often that some acousticians are using PMMA for membrane absorbers. This material looks pretty interesting but, unfortunately, there is almost no any information! Who have some information about it or maybe even expirience, can you share it?
Scan down to the part that says: "modification of properties". That only hints at the range of property modification that manufacturers practice. The point I'm making is that PMMA can be very different from plexiglass. Then again, maybe plexiglass would work in a panel absorber?
When you look at PMMA membranes, a whole bunch of other properties begin to kick in because blends such as PMA with PMMA and the addition of a dense filler can yield a rubbery product that could easily be mistaken for a filled vinyl like LMV, just based on handling it. Much of the research over the last 15 years on PMMA membranes have involved chemical modification that leads to controlled porosity and other treatments that affect the hydrophylic/hydrophobic balance, behavior in acidic environments, etc.
There is available some materials Acoustic PMMA/PETG
But almost no information about using it in studio design.
I'm pretty sure the "PETG" in that is glycol modified polyethylene terephthalate. The PET part of that is basically a polyester. The material in the link looks like a rigid polymer so the PMMA part makes sense but I don't know what properties they are going for. I don't think of the material in that image as a flexible membrane as much as a rigid panel.