How long do the protective qualities of Kevlar last and does sweat affect it?

Answer 1

The protective nature doesn't suddently stop. It will likely erode with time. They are just made out of layers of polymer (I think polyamide or maybe some polyester too). Those polymers are subject to slow decomposition which is accelerated by acid. Although the decomp is a very slow process. So, would a 20 yr old vest still protect? Probably. But to the extent of a new one? Probably not.

Answer 2

Not sure how much sweat affect kevlar but as I understand it Kevlar is a bundle of fibers going every which way and the structure breaks down over time with exposure to the elements to accepted replacement is every two years but do to costs and hassle there are vests that have been in service 5+ years that have worked just fine. At two years there is some break down in the structure and so weak points begin to appear.

Spectra Shield another type of vest material is more sensitive to moisture I beleive and I think the public is unaware of anything that is not Kevlar.

Answer 3

I work in law enforcement and we are supposed to be given new kevlar vests every couple years although it takes longer to actually get them.

Answer 4

It last until it wears out and sweat does not affect it

Answer 5

2 years and sweat does affect it.