Hi everyone, I am working on a new design with insulated clothing and I was hoping for some product selection assistance.

I am looking for a insulation that is designed to work while under compression. I know thinsulate works on this concept and I have found lamalite by wigley's. I was wondering are there other insulation brands that are designed to be under compression like one would expect in footwear?

I would also consider other insulations that meet the following when compressed:

1 need 2mm and 3mm of compressed insulation.
The insulation will be under roughly 15lbs a square inch of pressure at worst case senerio and must remain at desired thickness.
It must be flexible enough to be used in clothing.

I am looking for the lightest material with the given thickness of 2mm and 3mm. So any help with some names or suggestions.

Adam

Closed cell foam. Do you need compressible and pliable as well?

Closed cell foam. Do you need compressible and pliable as well?

Sorry, I need to read more carefully. As far as I know, Thinsulate is the best on the market. I've heard of something else recently, but not THAT recently (must've been hype).

Sorry, I need to read more carefully. As far as I know, Thinsulate is the best on the market. I've heard of something else recently, but not THAT recently (must've been hype).

Just thinking (excuse me??????????:eek: ) - could you use closed cell foam in high pressure areas (top of shoulders, back) and other insulation elsewhere?
Just a thought.

It is not necessarily that simple.

http://en.wikipedia.org/wiki/Thermal_insulation

Ah you are thinking of this by conventional standards. I don't really mind sharing, I am going to be vaccuum packing the insulation into it's shell. The point is too remove all the air and this is impossible with closed cell. Using an open cell foam is a poor choice because it offgasses and will destroy the seal with a few years. In this case the major factors influencing preformance will be tranferance, resistance and maintaining the seal.

I believe I have solved the technical part of maintianing the membrane and seal and now am identifying potential insulation materials. Foam is really out of the running. Compression and pliability is critical as I am using this clothing. Any places that are capable of ridge insulation will be done using my homemade aerogels.

Sorry about the double post, if someone wants to delete the other posting go right ahead. I just can't myself.

Adam

Well, if you have a way to maintain a sealed membrane, a vacuum works pretty well at preventing heat transfer.

But you may want to take moisture under consideration.

Two other very important characteristics for insulation in a clothing application is its breathability and weight.

Egads

AT- I am using getters that absorb gases and decisents that absorb moisture.

Egads- my design for this calls for near unlimited vetilation but no breathability through materials. If it is too hot fully vented it is too hot to wear. Weight and warmth are determined by how much material to make it keep a min thickness. The numbers say that 1mm of this material is equal to the warmth of 3oz of PL1. In theory 1 inch is capable of acheiving an R-value of 250. So basically for the weight saving to be useful, I need to use less insulation then 2oz PL1.

So at the root of my question what insulations will compress very little and at the same time are as light as possible. For instance 3.6oz PL1 will compress to roughly three quarters of 1mm. I have the clo values for different insulations and with that can figure out which is giving me my best options. I know older insulation didn't compress well so perhaps the older ones are my better choice.

Lamilite doesn't work well while under compression. The loft created by insulation like this is what creates the microclime to store heat. It's the air inside the insulation that provides warmth for light weight. Not sure how you're designing you project, but I'd research how microclimes affect compressible insulation and see if your plans still work.

According to Wiggy, Lamilite is the only insulation that can be STORED vacuum packed and reloft to its original thickness. But the insulation it gives while compressed is not equal to the insulation it gives when lofted.

I think thinsulate works the same way but I'm too lazy to research it...every compressible insulation I can think of works that way. :D

Good luck with your project. And you can call Wiggy for some advice on Lamilite if you have enough time - that dude likes to talk about his insulation! The number is on his website www.wiggys.com

I suppose that neoprene would be useless to you since it doesn't breathe, but neoprene is what they make diving suits out of. It compresses somewhat as you decend, but it is still the air bubbles trapped within the neoprene that act as the thermal barrier. (And yes, it comes in all thicknesses, including 2 and 3 mm.)

I have a pair of neoprene gloves that I now have to use in the winter due to some nerve damage in my fingers - the gloves are great, but don't take them off: the sweat inside the gloves chills rapidly, and it takes a long time to re-warm them! (They have to be turned inside-out to dry.)

Fleece is a pretty good insulator even under compression...mainly b/c it doesn't compress much.

i'll second the neoprene option. although i don't have any experience using it in dry or trail conditions, i surf year round in temps as low as 34 water/-10air and a good 6 mm suit keeps me toasty. it is really amazing how warm it will keep you, better than any other material i have ever worn. it does compress a bit but nothing like regular materials.
a bit on the heavy side compared to PL1 :(
anyways, it might be an alternative.... however i do not know specs on it since diy/gear addictions tend to run a bit less rampant in the surf world..

Shelter Builder; neoprene was something I thought about and it does come by thickness which is an advantage that isn't found in other materials. The problem is that neoprene is a closed cell foam and as such it is impossible to remove the air retained within those pockets. Since the way that I am hoping to decrease weight and size is by relying on the vaccuumed space for insulation I would just be adding weight to the neoprene with out seeing any of the benefits. The breathablity of the material is inconsequential because it will be air tight. I do enjoy neoprene and just bought a pair for my mother who has renyold's syndrome.

Just Jeff- You are right under normal circumstance air and the accompaning loft is critical for insulation. Compressing normally has an effect of lessen clo but that is only true if the material is not placed under vaccuum. Once that occurs the warmth is determined by core materials innate heat transferance and thickness and the level of vaccum. A true vacuum (like a flask) can provide r-values in excess of 250 an inch. Basically the insulation or core in this case is only keeping the vaccum from calasping into itself. It is the opposite of compressible materials.

So I am really looking for something light, flexible and when compressed will be said thickness. I was going to call wrigley on Monday with the holidays I haven't had much time.

Not sure I understand. If you vacuum pack the material, as in you compress it, conduction through whatever material is inside will be the primary mechanism for heat transfer...meaning that the vacuum won't really have an impact.

But I'm no thermo expert so maybe I'm missing something. Either way, looks like you just want something flexible with low heat conductivity. Why limit yourself to compressible insulations? Aerogel comes to mind.

In a vaccuum, the air that's trapped within the neoprene would expand somewhat but its pressure would decrease (because it cannot escape the neoprene); this is the opposite of what happens at depth, where the neoprene compresses and the volume of the air pockets decreases, while the pressure within those pockets increases. But in both cases, the weight remains the same; only the volume changes.

Good luck with your project.

I was wondering are there other insulation brands that are designed to be under compression like one would expect in footwear?

Some form of CCF is generally used as footbeds in footwear - they insulate while under compression b/c they barely compress. Thinsulate insulates the sides/back/tongue/toebox of footwear...where it doesn't experience that kind of compression. Thinsulate operates on the same principle of loft as other compressible insulations (they even have Thinsulate LiteLoft).

From the Thinsulate for Footwear (http://solutions.3m.com/wps/portal/3M/en_US/ThinsulateInsulation/Insulation/Thinsulate-Products/Thinsulate-Insulation-Footwear/) page (emphasis added):
Boots are a unique part of the outdoor wardrobe because of the pounding they take. Each step exerts tremendous pressure on every boot component. This harsh treatment is especially hard on insulation, which can become compacted. And since all insulations work by trapping microscopic pockets of air in their fibers, compacted insulations lose their effectiveness.

The qualities that make Thinsulate™ Insulation ideal for boots are its compression resistance and durability. It can take a beating and still retain those little pockets of air so important for keeping feet warm.

I'm not trying to talk you out of your project, and I'm still not sure I understand what your design is...just passing on info as I understand it. Best of luck with it - hopefully you get rich and become the new Patagucci!!

I'm still trying to understand what it is that you're trying to do. If I remember my basic theory on thermodynamics correctly, it is not only the trapped air within the insulating material that provides insulation, it is the material's ability to keep that air as motionless as possible that works toward heat retention. The fibers in traditional materials have the ability to trap (by fraction, I believe) a "boundary layer" of air - a layer of air that is only one molecule thick and is incredibly important to the whole process of heat retention. Strip away this boundary layer (say, with a good, stiff breeze), and you wipe away much of the fiber's ability to retain heat. The more fibers within the insulation, the more boundary layers will be present, and the more the pockets of "still air" will tend to remain still.

At least, that's the way I remember the conventional theory. And that's why I'm having trouble seeing where you're going with this. If you remove ALL of the air, won't the remaining material act as a thermal conductor, wicking away the heat?

Maybe I'm missing something obvious....:o

If the space is compressed, the material will conduct just as you say.

A thermos/flask uses a vacuum as an insulator b/c there's nothing between the two layers to conduct heat...not even air. That's b/c it doesn't compress so it's a true vacuum (or as close as we can get to one).

The effect of trapping air inside the fibers is a microclime. Look at a down cluster...it traps a bit of air inside the cluster. Your body heat then heats this air. As long as the cluster keeps the air from circulating with the cooler air outside, you'll stay warm...that's a microclime. Add thousands of microclimes to a certain thickness and you have insulation. Synthetic insulation does the same thing, just with threads instead of clusters. Some synthetic insulations even have hollow core threads to trap even more heat.

Interestingly, Thinsulate claims to have 1.5x insulating power than down for the same thickness. But they didn't say what fillpower down or give a weight comparison.

I will respond tomorrow in more depth but just to say that you are all right in a way. At the end of the day Jeff I am trying to maintain a vaccum with a controlled space like the flask. I would be replacing the metal with a membrane that service this purpose better but is missing the ridgity needed. This means that I need a core material with a poor ability to conduct heat and to maintain the vaccuumed space. This method works and has been used extensively for insulation. I am suggesting making clothing and sleeping gear using this principle.

As for aerogels, I haven't perfected my aerogel but right now it is roughly twice the weight of the current comercial aerogel and I am not sure what I am missing. None the less anytime I can I have used it as my primary insulation because it truly is amazing but there are too many times that a hard flat insulation pannel isn't effective or useful. The company who is helping me can only provide so much space in their machines and I haven't stock piled much either. I figure that about 35% of my overall insulation is an aerogel but I don't really see how to increase that. Any how I am too tired to type straight. Btw Jeff you gave me many interesting ideas for my hammock and shelter system through your website. thanks

Adam