Made in the USA

Earlier, Paul Tomblin wrote:

Some people I know who build canoes say that it's hard to get kevlar these
days because the military is buying it all up. Kevlar makes good light
structures for canoes, you'd think it would make good LSAs as well.

Well, it depends. Aramids like Kevlar are strong stuff, but at issue is
the fact that it isn't very stiff. So it adds a lot of toughness to
composites, but isn't all that useful for adding strength or stiffness
to primary structures. Glider manufactuers will tell you that they add
aramid to the cockpit in order to improve crashworthiness, glider
pundits will often joke that the aramid is just there so they'll find
all the parts in the same hole. I add Kevlar to some of my cockpit
parts to make them tougher and less likely to produce pilot-impaling
splinters.

BTW, the same "Military is hogging it all" stories are circulating
regarding ultra high molecular weight polyethelene (UHMWPE) products
like Spectra and Dyneema.

Bob K.