The D prize: for 1st synthetic down cluster

Would a light weight open cell foam that doesn't loft itself be available? I've been trying to build a quilt with inflatable battens that lofts the non self lofting insulation. Best of both worlds is my idea, fast drying and light weight. This may get the weight down. The battens in kites I build are inflated and work GREAT, reducing weight over titanium/carbon poles and other methods.

Anything synthetic that retains loft w/out assistance seems to be an uphill battle against weight savings. A quilt where the insulation weighs less than the shell would be something.

Would something like this be worth of the D prize? Or would synthetic down absolutely have to act like natural down? Kind of already covered that it would due to the uses of down in manufacturing. Is something else available to reduce loss of heat through convection that doesn't self loft, yet is still compressible many times over?

> Also, the misnomer that "synthetic insulation is effective when wet" is just wrong.
> Yes it may insulate more than none, but less bad doesn't equal good.

+1 Javan! I've been waiting for a thread where I could toss this in. I've seen numbers before, but can't find them- IIRC, down loses 40% of its insulation capabilities when wet, PrimaLoft 20%, and some other synthetics 30%+. It's a shame more of this information is available, similar in form as Richard's CLO charts.

why should a synthetic down process be expensive: the process hasn't been invented, so its a bit pointless and defeat-ist to claim it would be too expensive.

If the process is cheap, then the market could be as large as the synthetic wadding market, so why shouldnt it occur.

Also, I thought my idea of molten plastic into a vacuum would suit cheap mass manufacture.

"down loses 40% of its insulation capabilities when wet". How wet is wet in whatever study that was? When down has the potential to lose 100% of it's insulation value and at the same time the potential to not be able to dry out quickly in a practical way, I call into question the 40% claim above. Just saying. I'm not taking a side either way – am just looking at the what is possible.

Yeah 40% seems a bit low. After washing my down bag is was 100% delofted and took about 3 days to dry fully. I know washing is an extreme case but the down really does become a sort of mud when soaked.

i hope the quest for this continues. there could be some sort of event happen on our planet and all the geese may die. what then?

warm when wet is a misnomer … water conducts away heat 24x more effectively than air … so if its wet, then yr just going to suffer … the proper statement would be that no insulation is comfortable when wet … but given a choice between wet down and wet primaloft, the latter will still provide you with some insulation

the difference is that for thicker clothing, synth will dry much faster …. dont believe me? … soak a thicker down jacket or bag of equivalent weight as a primaloft one … and hang it till it dries .. yes i know BPL did some test which showed that some down sweaters dry as fast as synth ones, but those are THIN sweaters with lesser amounts down … try it with a thicker down jacket or bag, in fact try doing it with body heat at 40-50F temps, just make sure you have a heater near by so you dont end up hypothermic

as to "better" down … there will likely come a point when the gains in down fill power wont be possible anymore … already were seeing "900 fill" down acting as 700 fill or so in a 50% humidity environment … as check the weather right now, i wonder how much "fill" my MB EXL will give me this weekend in 90% humidity

give it a decade or two i predict that for all practical purpose synthetics will overcome all but the highest fill power down products …. already it doesnt make much sense to choose any 600 fill or less down products over the best synth … in a decade that number will probably move up to 700-800+

i remember reading in history books that all those english experts predicting that the longbow was and would be superior to firearms …. they were right for awhile, though no one really used longbows … but they failed to anticipate the rate of change and improvement of technology

in a decade or two, down will be a luxury product, used more for its cachet than its practical use … of course there are always people who still claim their wool mitts are the best for mountaineering =P

The 24x difference in conductivity between water and air is an irrelevant factoid

The problem is that it loses loft as the fibers get wet. The volume of the bag will still be mostly air. There won't be much water in it to conduct heat.

I guess my comment about 24x difference being an irrelevant factoid is an irrelevant factoid because everything else people have said is good

and the other bad thing about being wet is that your body heat will start drying it out

takes much more than 24x to evaporate water

jerry .. its very important

if a person is hypothermic you strip out all wet clothes and out them in a dry bag, or under dry clothes with someone if possible naked, you dont leave them in wet wool/fleece/primaloft … as anyone who has gotten soaked, moist, damp knows, anything that is wet will transfer heat away much faster than something that is dry

the bottom line is that wet clothing sucks … so make sure you dont get it wet … or it dries quickly

http://www.backpackinglight.com/cgi-bin/backpackinglight/00184.html

Warm When Wet?

While there are both natural (e.g., wool) and synthetic fibers (especially, relative to down) that are more resistant to the fiber structure collapse induced by the presence of liquid moisture, there is no fiber in existence, be it natural or manmade, that can fairly make the claim that it is warm when wet.

I agree that wet is bad, nothing really to argue about

I should quit being an engineer and just blank out when I read about the 24x conduction

If the volume of your sleeping bag insulation became filled with water, then the 24x conduction factor would predominate, but that's not what happens

It's that your sleeping bag is thinner because of fiber collapse (after your point #3)

and the evaporative cooling (your point #3)

When synthetic insulation gets wet in realistic situations, most of the volume is still air

Even if you totally dunk it in water, then take it out, most of the water will quickly drain away, and you'll be left with mostly air, so it won't have 24x conduction

> though no one really used longbows …
Tell that to the French who were slaughtered by the thousands at the Battle of Agincourt. OK, the British tactics had something to do with it as well, but their weapon was the longbow.

Cheers

jerry ,,,

there is still enough moisture that the higher conductivity of water is a factor … as anyone who has worn a wet base layer in the rain can attest to … wet clothes that are wet against the skin will conduct heat away faster than dry clothes … which is why you want wicking base layers … wet rain jackets in the rain "feel" colder than dry rain jackets at the same temp

if the difference between water and air was not an issue … you would be able to wear that wet cap4 (dont see much collapse in that when wet) all day long and still feel as comfortable as warm as with a dry one … unfortunately anyone who has worn on soaked knows differently

yes evaporative cooling is an issue …. but how about when its raining in high humidity environments … how much evaporation is there .. i can tell you its still darn cold all that moisture when yr wet

as to loft loss … with primaloft it should be "minimal" if you believe them

from the same mr jordan article as above …

Conduction is also a major source of heat loss in wet clothing, due water’s excellent conductive properties.

http://www.backpackinglight.com/cgi-bin/backpackinglight/00184.html

as to longbows … once firearms came into widespread use, know of anyone who used longbows against them successfully?

im sure that when people saw the first horseless carriages, some said to themselves …. "horses are and will always be much better"

Ryan, in his article, states points 1, 2, and 3, and the part after 3 without any supporting references to any data or anything. He did refer to a 1992 Mountaineers article.

But that's okay, I am just stating my opinion without any data.

There is so much anecdotal information out there and it is so difficult to get realistic data.

For example, the primaloft loft retention data chart said this was after 1 minute of immersion in water. I wonder how that correlates with real world getting wet in the rain and sweat?

I think that if primaloft retains it's loft when wet then it should be a lot better.

I just got several yards of primaloft so I'll have to check it out.

Sorry to be so skeptical : )

lol … nothing wrong with skeptical

what i do know is being wet sucks … but eventually youll get something wet sooner or later … just make sure you can dry out

I've been there before – wet definitely sucks

The whole 'warm when wet' thing was just a poor choice of words by the industry. It's more like 'it still will work and insulate even after it WAS seriously wet. About all that will be wet in a synthetic bag after being totally soaked and then hung for a few minutes is the lining and the shell and if those are repellent then it's good to go. Even if the shell and lining are still damp or wet, survival is assured.

It should be pretty apparent to anyone that it is impossible to even soak a synthetic bag and get it to hold water like a down bag will. All a person has to do is a comparative washing. The first thing a person will notice there, though, is just how difficult it is to completely soak a down bag quickly, but it is even more difficult to dry it once it is completely soaked. Most of the stories I have heard regarding down becoming worthless are climbing stories, especially climbing on big walls where people get trapped, end up in waterfalls and etc.

I am an advocate of using at least some synthetic. Everyone carries synthetic layering these day. I no longer use down sweaters as nice as they are. I prefer the security of synthic fill even though it's a bit bulkier to get the same warmth. If the rain gear fails for any reason in a trapped type situation or whatever, the water does not accumulate. In a big Fall Sierra storm a few years ago, me and my partner did not know what the outcome was going to be. It was getting pretty nasty, so the first thing I did late in the night in my Integral W/B tent was put one of the Western Mountaineering bags away in the stuff sack to preserve it, and use the other as a quilt for both of us. She liked it! I would not have worried so much if I had Event on the outside of my bag like I do now. It's always good to think in terms of the days ahead in case things don't improve. I'm not preaching to the quire here, but to those that are reading that may be less experienced.

I suppose to win: product would need to be as long lived as down (keeps performance), as compressable, mass manufacturable, as warm for weight, etc