Corner bass traps in plastic stretch wrap foil?

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ancanar

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Hello. I want to build corner bass traps from Isover's PT-80 tech slabs.
I wont to just cut them into triangle shape and put in the corners.
However i am highly allergic and would like to ensure they will be safe for my health.

Will it affect their functionality if I'd wrap them with plastic wrap foil like the one here that is used to wrap packages?


And if it would harm the traps' effectivity could You suggest other material that will asure no particles from the mineral wool will go into air?
 
I can't say for sure if the plastic would change the effectiveness, but I suspect it could impede the sound waves from reaching the rockwool (where the sound energy is absorbed and trapped), and may flap or vibrate depending on how tight it is.

Once you have the mineral wool built into the bass trap, there should be zero particle generation if you simply cover it with a suitable fabric. It's only in the cutting process that you generate any dust. If you build the trap to use a whole sheet, then you have no cutting. If you are concerned about creating dust, wear an N95 mask while assembling, including cutting any wood.

The mineral fibers are encased with a bonding resin which will prevents them from migrating. The resin system is stable. It's doesn't melt or evaporate. To degrade it you literally need to burn it at about 390F, at which point it degrades. In addition, the fibers themselves are inert, they don't react, but are mechanical irritants. They aren't classed as carcinogenic. If you read the safety data information, you need to realize that this if for people working with this material every day, as in someone who is installing insulation 5 days a week. Even then, rockwool insulation isn't even regulated by the US OSHA as a hazardous material. Safe n Sound (a brand sold in the US for sound insulation is actually certified GREENGUARD GOLD status for indoor air quality. You should be able to look at Isover's information to see if it is similar.

Greenguard Gold certification is from Underwriters Labortory in the US. You can read what this means here:

www.ul.com

What Does "GREENGUARD Certified" Mean?

If you’ve shopped for paint or bought a crib or mattress or new flooring, you might have seen a GREENGUARD Certification mark on the product packaging. But what does it mean, exactly, and how can it help you enjoy cleaner indoor air?
www.ul.com www.ul.com
 
For a project many years ago, I had some thin waterproof covers for some speakers made out of thick vinyl type material, and found the practical result was all the HF vanished totally, but the low bass was virtually unchanged. One design of bass trap uses thick roofing type material to soak up the bass energy. My guess is that covering them will just change the properties of what the traps do. They might even remove more bass, but this is an experimental thing. The tightness of the membrane will change what happens.

What I do know is that rockwool is a great absorber, but that it does it's job by moving. Incoming energy is mechanically converted into heat. I pulled out some rockwool filled acoustic panels from a BBC studio, intending to repurpose them. timber frames, hardboard rear panel, and decorative fabric on the room side. Probably been in place 20 years? At the bottom was plenty of rockwool dust. Rich's info above might help you establish how dangerous to you the dust is. Look inside your studio computer to see the amount of dust already in the air. I've often wondered where that comes from,
 
Thank You for the info. What type of fabric would be good and safe replacement for that plastic foil?

EDIT:

Some of You spoke about membrane but I just want to simply wrap them from all sides with the foil not build some kind of wood casing and cover the front with tense foil membrane. I don't have the skill to build a casing.
 
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What size are the particles you are allergic too? If the idea is to trap dust you could react to, the idea is to let audio through and be a barrier to physical particles. Your wrapping is a barrier to both. Nylon mesh - as in what they use to make tights and stockings (is that what the US call panty-hose?) has a variety of mesh sizes from very fine to very coarse. Loudspeaker grill fabric has the same requirements - be invisible to sound, but stop light.
 
rob aylestone said:
What size are the particles you are allergic too? If the idea is to trap dust you could react to, the idea is to let audio through and be a barrier to physical particles. Your wrapping is a barrier to both. Nylon mesh - as in what they use to make tights and stockings (is that what the US call panty-hose?) has a variety of mesh sizes from very fine to very coarse. Loudspeaker grill fabric has the same requirements - be invisible to sound, but stop light.
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Would something ike that work https://www.ripstop.pl/en/produkt/ripstop-poliester-300d-ciemno-szary/? Or classic bylon would be better? I found nylon of 70 DEN but i am not sure how the scale works beside that higher den means heavier yarn.
 
I think that simply wrapping the panel would be more likely to cause the possibility of breaking the rockwool down inside. It makes it possible to crush corners when moving, and if it gets bent, it's more likely to break apart. A simple frame made of something like a 1x4" (20x90 mm) board is very easy to make. A saw, drill, a screwdriver, some screws and a staple gun is all that is needed. Since you'll cover it in cloth (a stretch polyester fabric would work) things don't need to be pretty. It allows you to secure the fabric more securely as well.

A frame would also make it easier to stand unless you use really wide panels.
 
TalismanRich said:
I think that simply wrapping the panel would be more likely to cause the possibility of breaking the rockwool down inside. It makes it possible to crush corners when moving, and if it gets bent, it's more likely to break apart. A simple frame made of something like a 1x4" (20x90 mm) board is very easy to make. A saw, drill, a screwdriver, some screws and a staple gun is all that is needed. Since you'll cover it in cloth (a stretch polyester fabric would work) things don't need to be pretty. It allows you to secure the fabric more securely as well.

A frame would also make it easier to stand unless you use really wide panels.
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The boards have to be specific ones or only the front covered in cloth is what matters? I have a lot of around 4mm thick HDF boards left. Would they be ok or to fragile?
 
4mm would probably be too thin. I don't know how you could fashion a frame out of that, except to glue it.
 
I have read a few times that you can leave GF in its plastic bag and it works just as well as bass absorber.

This seem entirely logical to me as we all know that LF is very penetrating, a 2 layer stud wall won't stop it so I doubt a fraction of a milimeter of flexible plastic will have much effect?

Dave.
 
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