Polartec Alpha

[Moondog55]

Has anybody here yet worked with it?
I know that it has mixed reviews on BPL but the stuff is intriguing as a possible blanket fabric substitute at a tenth of the weight
Mill Yardage has a sale on second quality 90GSM stuff at the moment and only $9.99USD a yard
It has been suggested as filling for a bivvy sleeping bag my UnderclingMike but I was thinking of the insulation for a big pullover parka or camping quilt that may get a lot of abuse
Just another thought experiment at the moment due to the cost of postage

[wayno]

alpha?
it usualy has a highly breathable knitted style fabric on the inside, doesnt retain heat as much as standard quilted materials. was designed originally for the military to avoid overheating in cool conditions so they could wear it under their webbing and not have to remove it too often...

[Moondog55]

Yes Alpha
I just noticed the mistake and corrected it.
I ask as it have a very high Clo value for the weight
And despite being usually used with highly permeable fabric as the shell I would have thought it would work equally well using windproof shells.
Underclingmike directed me to a Japanese bivvy sleeping bag using it as the thermal insulation with WPB outer and it made me think
I'm working on a fantasy project for our next trip to the USA, trying to get up to the Arctic Circle that trip

[wayno]

the outer shell is windproof, the inner material is the more breathable one, its easier to spill heat out of it when you unzip it because it doesnt get retained as easily with the highly breathable inner fabric...

[Moondog55]

The outers on the jackets I looked at in America were far from windproof Wayno, only moderately wind resistant, I think there are many ways of using the stuff

[wayno]

i own one, its pretty windproof, if there air trapped in it when i wash it it keeps floating on the surface because the air doesnt get out easily

[Moondog55]

Wayno the style of parka I'm thinking of making is in this link below although I'll probably use a raglan sleeve and no zipper at all, just a simple gusseted neck pullover

https://www.uaf.edu/files/ces/publicati ... -00072.pdf

All of my current deep cold gear tops have full length zippers and I want to try something different

[wayno]

so are they just selling the insulation? its like a very low density fleece with a string vest type backing to hold the fleece on.
its up to the clothing manufacurers to decide what shells they put on it and they can vary. but they usually opt for highly breathable because thats the advantage of polartec compared to traditional synthetic fillings as those would escape through an open knitted fabric whereas the alpha is held in place by its backing marix material

[Moondog55]

Yes I'm thinking of just getting some 90GSM seconds from MillYardage in the USA and combining it with the 40GSM thinsulate I got super cheap from Spotlight. Clo value of Alpha is similar to the Thermal Pro, being 0.34Clo per ounce
90GSM would have a Clo value close to 1, I thought coupled with the Thinsulate which has a Clo value of 0.84 it would be both relatively lightweight and warm enough as a primary shelled layer

[undercling-mike]

Just popping in here to say I don't really know anything about Polartec Alpha and perhaps it came up in a conversation with someone else Moondog?

[Moondog55]

Hmmm Maybe I thought is was when we were talking about fabric for sleeping bag shells
Looking back it seems I was confused; it was Neoshell you gave me the link to when I was asking about the scrap of Robic fabric
Anyway I thought somebody somewhere in Japan had used it as sleeping bag insulation for mountain bivvies, and actually I'm surprised somebody hasn't