aerogel thermalwrap by cabot

[Jeff Cadorin]

http://www.cabot-corp.com/Aerogel/Apparel

this looks very interesting. I am going to write them and see about samples

*edit*
here is the email I sent.

In researching new ultralight technology in outdoor fabrics, I was pleased to find your website. I am specificaly interested in the weight per square yard, thickness, drapeability, and clo value of your three fabrics? What roll sizes are available and how much it costs? How can I recieve some samples of this material for new product research? All inf on your Thermal Wrap material is greatly appreciated.

Wait and see what they respond with

[Colin Krusor]

You may have found this already, but Cabot Thermal Wrap is almost identical to Aspen's aerogel blanket materials (the patent expired). This is the same material as the stuff used in Toasty Feet insoles, POE aerogel sleeping pads, and Burton ski jackets. I've used it to make experimental sleeping pads and insoles, and I've used it at work to insulate cryogenic vessels.

I think it has some potential for sleeping pad and apparel applications, but not to the extent that some imaginative members of the MYOG crowd might hope. It has several shortcomings.

The product is a polyester felt mat filled with aerogel dust. It is extremely dusty (this is why Aspen and Cabot both advertise that their products are "less dusty"). Any flexion of the blanket causes large quantities of fine aerogel dust to be lost, eventually leaving only a polyester mat. This isn't a problem for insulation of pipes or cryogenic vessels, but it is a problem for apparel.

It is very heavy compared to typical apparel insulation (very low insulative value per unit mass). I think Richard Nisley calculated that, per unit weight, high fill power down is 52 times warmer than pure aerogel (and the Cabot and Aspen blankets are not pure aerogel). It only excels as an insulator when low volume and resistance to compression are important, not low mass. An aerogel jacket or sleeping pad could be extremely thin, but also be very heavy. One of the materials I have used is Aspen's Spaceloft 6250, which is 6mm thick (about 1/4 inch) and it weighs over two pounds per square yard.

So, for applications where low volume and compression resistance are important and the required quantities are small (like gloves or insoles), aerogel blanket encapsulated in plastic film could prove serviceable. For other kinds of apparel or in sleeping pads, it's just too heavy.

Aerogel granules under soft vacuum (10 torr) in metallized barrier film envelopes have much greater potential, in my opinion. Panels of vacuum-sealed aerogel granules are half the density of aerogel blanket and their insulative value per unit volume is five times greater. An inch-thick piece of eva foam can achieve R5, an inch-thick piece of aerogel blanket can achieve R10, and an inch-thick aerogel granule vacuum panel can achieve R50.

[Jeff Cadorin]

Colin. I had read some of that info. The page linked to I thought was a new impregnated product. Lots of good info you supplied. I would still be happy to mess around with s ome samples.

[Nick G]

I hate to bump an old thread, but I ran across the same product as Jeff and the numbers don't seem to quite match up with Colin's conclusions for the materials. Maybe it's best to give this a little more thought.

First, the data sheet I'm working off of:
http://www.cabot-corp.com/wcm/download/en-us/ae/Data%20Sheet%20Thermal%20Wrap%20TW350_600_800_4_2011_FINAL.pdf

The densities that Colin mentioned aren't matching my calculations. At the Cabot listed density of 70 kg/m^2, then an 8 mm thick blanket should weigh 20 oz per square meter, or about 18 ounces for a standard size pad (183 cm x 51 cm). If the R Value is as high as it ought to be, then this would make for a very nice pad indeed.

I'm still struggling with how to convert the thermal conductivity performance listed on the datasheet to an R-Value that we can recognize. Does somebody know how to do that sort of calculation?

It seems like the issues with toxic dust and loss of aerogel could be taken care of by a simple outer layer of polycryo or some similar fabric.

If the final pad comes out to 22 oz, then an R value of 5 would make it the most weight efficient full length pad on the market. It would need an R Value of 8.5 to beat out the Neoair X therm for the best pad overall (I believe the r value is much lower than this, but I don't know).
See my calculations of market pads here: https://docs.google.com/spreadsheet/ccc?key=0AoQR5Mz_cmEudGlZcW1hNUg0OHd2ZGZmSWdOT2lvd1E#gid=0

Maybe I'm completely off track here or unable to do math. I honestly wouldn't be surprised.

[David Franzen]

conversion of units: http://en.wikipedia.org/wiki/R-value_(insulation)#Units

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