Please visit www.toyobo.co.jp for more information on zylon fibres and their grades. It is being regarded as an easy replacement for Kevlar in ballistics but there are issues. Can you throw some light on this ?
Probably Zylon is not popular due to fact that policeman was hurt although he had a vest made of Zylon. After that NIJ suggested to remove vest made of Zylon. Here you can find more info: http://www.nytimes.com/2003/12/26/us/company-s-bulletproof-vests-are-questioned.html