|Quoting Tdscanuck (Reply 4):|
Kevlar has an extremely high toughness, unlike glass or carbon. As a result, you effectively can't pull it or bend it apart, you have to shear it. If your cutter damages the matrix to the point that the fiber is "free", it'll just flop around forever and never get cut. Imagine trying to cut limp fishing line with a knife...you need to get the fiber in tension to stabilize it before you can cut it.
I'd imagine Kevlar is much tougher, but I wonder if it's conceptually similar to machining FR
-4, which I had to do a fair amount of at my last job. Although, even though FR
-4 has woven fibers, they are encased in an epoxy or whatever. But many times, you'd end up with tons of little strings hanging off of a machined edge.
Not to mention, I had to use end mills with the titanium-nitride coating - they could resist higher temperatures, and that FR
-4 got HOT
if you machined too deep at once (not to mention, the machine I was using didn't have coolant). I ended up machining in depth cuts, probably 0.02" at a time or so.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".