sound attenuator/absorber material with high thermal conductivity? 1

[Zakal]

I am sorry if this is coming to the wrong forum;
Anyone ever heard a sound attenuator/absorber material with high thermal conductivity?

 

[MikeHalloran]

Concrete works well along highways, probably because of its mass.

That probably wasn't what you were looking for.

My goto guys for sound issues are Soundown.

http://www.soundown.com

All of their stuff I've used uses a thin mass-loaded layer of solid-ish plastic between layers of plastic foam, but they may have other stuff that will work in your world.



Mike Halloran
Pembroke Pines, FL, USA

 

[IRstuff]

Perhaps some background information would be useful, i.e., what will the thermal conductivity be doing for you?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Zakal]

MikeHalloran, thank you very much, I am checking them right now,

IRstuff, I am afraid I am not permitted to provide intimate details since this is a research for a new project, I apologize. I can tell that the I need an attenuator/absorber which does not obstruct the cooling process… In other words, it must help dissipation of the heat produced by the component which causes unwanted noise.

 

[btrueblood]

Helmholtz resonators are used in jet and rocket engines, and can be made from almost any solid material, including copper or aluminum.

 

[Zakal]

btrueblood, thanks a lot, yes, we are using them too.

Your post just reminded me what I forgot to mention initially:

We need it in foam form, if possible, max 1 millimeter thickness.

I think what we need is an thermally conductive open cell foam..

Can anyone recommend a source?

 

[btrueblood]

You want a high conductivity polymeric material...any unobtanium coating on that?

There are reticulated aluminum and carbon foams available for sale today...but bring your wallet. And they won't have the viscoelastic damping properties of elastomeric foams.

 

[Zakal]

"...any unobtanium coating on that?" !

btrueblood, is it that hopeless?! ))) See what I just found (attached pic, it is from 3M, thermally conductive interface pad…), if provided at reasonable cost, this will do.. Do you have any idea who else has this at a reasonable cost? (Max continuous working temperature will be 100C)

 

[btrueblood]

Sil-pads are another make.

http://www.bergquistcompany.com/thermal_materials/sil-pad.htm

 

[Demon3]

Sound deadening is often achieved using a soft, lossy polymer filled with a high density mineral. Companies like BMW, Volvo, GM and many more use such materials. That means you'd need a high density mineral with high thermal conductivity. High density minerals include barium sulfate, magnetite and hematite. Of those hematite has by far the highest thermal conductivity of 12.5 W/m.K and a density of 5.2 g/cm3. It's hard to find it in pure form and milled to the right size to be a filler so I actually helped create that product and it was launched last year under the DenzFlex tradename. Note, I do not sell the product, nor do I make any money on sales. Magnetite has the same density but only half the thermal conductivity.

By using a high loading, typically 60-80 weight% of filler you should be able to get a thermal conductivity of the composite over 1 W/m.K. That's not a guess, it's what's been reported in articles.

Chris DeArmitt PhD FRSC
President

Plastic materials consultant to the Fortune 100

http://www.phantomplastics.com

 

[Zakal]

Dear Demon3,

Very good info, thanks a lot,

I will check every info you mentioned,

In the mean time, as silicone is very expensive and the max continuous working temp in our application is around 100C, I am looking for alternative base materials, can you think of any candidates to fill?