Question about Mineral Wool

rob aylestone

Well-known member
I'm guessing that the rigid construction probably accounts for the lower attenuation figures at the bottom, but interesting stuff, none the less.
 

jimmys69

MOODerator
From what I understand, higher weight/density rockwool can be good for low end absorption, but at the expense of high end reflectivity above 1000hz. Seems that thicker low density products like the pink fluffy, require more depth, but result in better broadband control and even lower frequency absorption at the cost of intrusion into room. Then there is the limp bag theory of containing the fluffy sealed in a bag, and then facing with layer of low density fiber in front to absorb the high end. Have not seem testing of the two types HD Rockwool and fluffy stuff used in combination. Nor have I really heard anything about polyester fiber panels. I suppose we are all guinea pigs if we don't now the details and testing results...

I do know from experience that egg cartons are useless!!! LOL
 

witzendoz

Senior Member
Polyester is the only sound absorber that can be used in hospitals and public venues in Australia for sound control. Its a no brainer to use, no fibers is so good to work with and be around and the stuff works as good as or better than fiberglass. My studio was the fourth I built and I said to myself no more fiberglass when building it, I even used it inside the walls and ceiling.

Cheers
 

Ed Fones

Well-known member
About 15 years ago I purchased some polyester house insulation made from recycled plastic bottles. I still have a roll or two left over. For sound insulation it is dire and completely ineffective. Maybe its how they weave the stuff together?

People always asked on its fireproof properties. It does actually melt away from the flame but will burn eventually.

I think it would work better as a sound treatment more than a sound insulator. But then I know nothing.
 

Ed Fones

Well-known member
Polyester is the only sound absorber that can be used in hospitals and public venues in Australia for sound control. Its a no brainer to use, no fibers is so good to work with and be around and the stuff works as good as or better than fiberglass. My studio was the fourth I built and I said to myself no more fiberglass when building it, I even used it inside the walls and ceiling.

Cheers
I am in no way arguing what is right or wrong, but just offering some food for thought.

Billions of tons of asbestos used mostly in western countries until it was banned 20 years ago. A lot of that stuff was used in brake and clutch linings. That dust spread around the roads, villages, towns and cities you inhabit. It was also used in roof slates and corrugated roofs, pipes, guttering's, paints, panels, heating appliances, cooking appliances, plumbing fittings, electrical wiring and fittings, oven gloves, protective clothing, just about everything in your home, workplace and life. The dust is still there. It does not dissolve over time. It stops in its present form. It is so fine it passes through filters unless specialist ones to capture it. The roofs of buildings are still covered in it today in nearly every town and village and city in your country. All slowly emitting fibers into the air around you every second of the day as the elements break the roofs down. It is a natural rock found in most countries and must degrade into the environment same as other rocks?

Glass fiber and mineral wool. This has been around for nearly 200 years. It has been used in conjunction with the above and in just as many things. Its dust is everywhere. It doesnt burn. I think it actually degrades into a dust. It too is used in roofing and breaks down daily.

Plastic and more importantly plastic fiber. Polyester, nylon etc are just a few names we know of from our clothing. These materials have been used in clothing and all sorts since they have been invented. Tens of millions of tons are produced and used annually. In a normal household wash, hundreds of thousands of minute particles are released into the water which they have now found is causing micro particle pollution and getting into our food. The effects we still do not know about. As you wear your clothes, the rubbing and wearing of that plastic material breaks down into what must be millions of particles daily off nearly every single person on the planet. Added to this. vehicle tyres are made from plastic and every time a vehicle moves, it grinds those tyres into nano particles which join the other dust all around you.

Maybe when they start looking if they havent already, they will find lots of the stuff inside us..........together with the formaldehydes, pesticides, herbicides and every other poison on the planet. As Dylan said..........'It's blowing in the wind.'

I'm sorry its too late. If your worried about dust, we are already f***ed.
 
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Ed Fones

Well-known member
The stuff I talking about is not recycled plastic bottles it is professional sound treatment. 🤦🏻‍♂️
Point taken, but polyester is just plastic. Whether its recycled or new raw stuff, it is just plastic. The house insulation which you can still buy is made into a fleece type of material as in clothing. How is your sound studio stuff made?
 

Monkey Allen

Fork and spoon operator
The rest of the answer, it does cost more than fibreglass, however when making traps and gobos you don’t have to cover it. It will absorb 100hz if you build it into a bass trap, just like high density fibreglass. I live in Australia.
So you used the acoustisorb 3?
 

rob aylestone

Well-known member
Professional doesn’t have anything to do with using virgin material. The factory want a specific grade of polyester. They source it from the most appropriate source. Who cares if it comes from waste plastics, if it’s chemically the right stuff.
 

rob aylestone

Well-known member
There's a great video on rockwool manufacture here
Then there's this Australian video about the polyester stuff - which is indeed 80% recycled -
 

Ed Fones

Well-known member
Here's the stuff I bought and for sound its no good. I remember it was terrible to cut.

 
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Ed Fones

Well-known member
Just looked at the Acoustisorb 3 spec and thats 80% recycled plastic. So if it aint recycled milk bottles its some other kind of recycled plastic.
 

Monkey Allen

Fork and spoon operator
Here's the stuff I bought and for sound its no good. I remember it was terrible to cut.

I thought you said the stuff you used did a good job?
 

jimmys69

MOODerator
From what I have found and understand, the polyester stuff is in testing is not worth the cost, nor the performance abilities. I suppose if you wish to work in a hospital environment , then you must.
The data even supplied by manufacturers of this type of product shows that it is not good for low end frequencies. Hell, without taking a good chunk out a room, none of them are. Most rockwool products are reflective above 1k, so you have to add another layer on top of things like superchunks or 4" panels to work with the upper end reflections effectively.

I am looking at 28" deep for my control room back wall that also includes 13" of limp bag low end absorbers, 8" of fiberglass broadband, and a line of 6" membrane traps for the sub 100hz frequencies to make my room as good as it can be. Oh, also an array of diffusers on top. This is all with the pink fluffy stuff involved that does perform much better than all other types and is way cheaper.

That is not to say that other designs and lesser degree of control is not effective in the majority of home studios. I am just going for the best I can get for my particular space. That being done with testing and accurate design for the size and needs of my space by a competent designer. I am just giving advice that is basic to the full design of my space.

I however, am in no way concerned about the airborne fibers. It is all contained. Worked with it all of my life, and am still kicking.
Just my personal input. I am not arguing anything here. None of us know until we know in our own space what actually works for what we need.
 

witzendoz

Senior Member
I thought you said the stuff you used did a good job?
The acoustasorb 3 is so dense you can’t roll it up, if you stand it up against the wall it will stay there. Yes I have used it throughout my studio builds as sound proofing, building bass traps and making gobos.

The fluffy stuff you have is normal home thermal insulation. Acoustasorb products is made for acoustic treatment.

Cheers
Alan
 

Ed Fones

Well-known member
The acoustasorb 3 is so dense you can’t roll it up, if you stand it up against the wall it will stay there. Yes I have used it throughout my studio builds as sound proofing, building bass traps and making gobos.

The fluffy stuff you have is normal home thermal insulation. Acoustasorb products is made for acoustic treatment.

Cheers
Alan
Now that is different than the stuff I purchased for house insulation.
 
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