Recycled Plastic insulation as acoustic treatment

[dayna]

Hi
Looking for thoughts on Recycled Plastic insulation as acoustic treatment for a home studio. I suffer bad reactions to rockwool and variants of that, but have no problem with Plastic insulation. I can obtain it in rolls as far as I know, and have considered full rolls as bass traps stood in corners, and filling for overhead panels. Looking for feedback on this.
Many thanks
Mike

[Wonks]

Can you give a specific brand, or provide a link to what you were thinking of using?

[Wonks]

The first example I came across for Thermafleece - SupaSoft Polyester Insulation, had a density of 13kg/m3. Rockwool RW3, the one normally recommended here, has a density of 60kg/m3. So less than 1/4 the density

I fear that it will just be far too light to provide much acoustic treatment (except at the high end) unless you use very thick panels indeed.

[DanDan]

Autex, they have a UK operation. https://www.masacoustics.it/wp-content/ ... -Sheet.pdf

Caruso Isobond, sorry probably only EU https://www.don-audio.com/Caruso-B100-B ... er-Isobond

[Wonks]

That Autex looks interesting. Scaling up the weight to 1m3 of it, it comes to 96kg/m3, so is a lot denser than the loft-insulation style products.

That's denser than the recommended rockwool density for bass traps, but it is a different material, so needs to be looked at for its own properties.

Any info on sound absorption for thicker panels e.g. 2x 50mm thick panels? the Autex site seems to have lots on their ready-made architectural products, but short on the basic material properties e.g. at at what point does increasing the thickness stop providing increasing low frequency absorption benefits?

[Dynamic Mike]

If you're constructing your own traps then perhaps consider increasing the density of something like Thermafleece by fitting a baffle & containing it under compression? Surely if you halved the depth then you'd double the density. With it essentially being plastic fibres I suspect if you overdo it then it might become increasingly reflective but it looks loose enough to allow some compresion.

[Drew Stephenson]

Making dual density absorbers is also worth considering, with the lower density side facing the room.