machining Kevlar

[WoodChuck34]

So here's a new one. My sister is a jeweler and apparently one of the machines she uses does some sort of pressing and requires 3" x 3" x

1/4" squares of Kevlar.

Anyway, I told her I would try to cut some with a very expendable saw blade. Kevlar does not have any metal in it, but does anyone out there know:

1. Is cutting this stuff going to kill my machinery. I used the mitre saw in the test, but if possible, would cut it on the tablesaw.

1. What kind of blade should I use? I cut it with a 32 tooth carbide in the mitre saw, but it was a very old blade. There were some sparks flying, which I assume was from the blade. Would an abrasive blade be a better idea?

I did a rec search and couldn't find anything. If I am able to cut this stuff, it would be great for things like a router table insert, because this stuff won't bend.

Chuck

[Hitch]

Try asking at rec.crafts.metalworking. Those guys know a LOT.

[Eric Johnson]

My only experience with it we used the router bits we have for solid surface counter tops without any problems but that was just for shaping. I didn't do any straight line cutting.

EJ

[Young_carpenter]

Funny I was wondering about that too. If it works anything like SS then a good sharp HQ blade will cut it fine. I didn't know that Kevlar was a solid material, I thought it was like cloth.

[Rich]

Is the Kevlar by any chance steel mesh reinforced? I have this in a bullet resistant vest. But the some of the panels in one of my vests are not and can be seperated then cut with scissors. How compressed is the Kevlar? Sounds like it is solid too me and I would think that would make it easier to cut with something high speed. Maybe a dremel tool?

Rich

[Rich]

Well it is actually fiber woven into strands that is then woven into a cloth, but like fiberglass matt it can be made into solid very hard sheets. Thats what I am thinking. Several layers impregnated with a type of resin then compressed. But it shoudl be able to be cut without difficulty I have a good bit of Kevlar thread which I can easily cut with scissors but when woven into cloth and layered it is very strong. A bullet can and will pass through Kevlar. I know first hand I have a small cal. bullet lodged in the very last kevlar panel in one of my vests.

Rich

[GTO69RA4]

Isn't Kevlar just a plastic like any other, just stronger? It's popular in fiber form, but I'm pretty sure I've had stuff that was made from the solid material.

GTO(John)

[Andy Dingley]

What form is the Kevlar in ? Fabric, or laminated up as a rigid sheet?

I sew, and I often sew Kevlar (or aramid, to use the non-brandname). It's not magic.

If it's fabric, then any large sewing shears will cut it (in single layers). It's not good for them, so either don't use your best pair, or get a pair of Kevlar shears (harder edges, PTFE coating). You don't need ceramic edged shears, they're hugely expensive and yet also damage prone.

For 1/4" sheet, that's a few layers of Kevlar fabric quilted together. It sews easily, as it's usually loosely woven.

If it's rigid sheet, then use a hacksaw and a HSS blade (or bimetal blades are generally better). Wear on the teeth will be rather high, but it will hacksaw easily enough.

[John Crea]

Would think an abrasive wheel/blade would be best, as Kevlar is very CUT resistant and could jam a toothed blade.

Have you contact the MAKER of the kevlar and asked about what they recommend???

John

[Yitah]

My advice - don't use a blade you like

I Just cut holes in some carbon fiber, a 1/8" thick woven mat with PEEK matrix using a HSS flycutter.

Had to sharpen it about 5 times. Aramid (Kevlar) is also very abrasive and is likely to put some serious hurt even on carbide.

Y

[Hylourgos]

I've worked with Kevlar rope a little, but that experience won't help you with the cutting question. The many questions I did have were quickly answered by Dupont, whose techies are pretty sharp.

Try them.

H.

[WoodChuck34]

Wow, thanks for the quick responses. Just to clarify, this Kevlar come in

6" x 6" tiles that are 1/4" thick and its very hard. I found a Freud blade designed to cut Corian type laminates, but that's as close as I got. I'll try contacting the manufacturer and let everyone know what I find out.

thanks

[Young_carpenter]

as rich said it is used in conjunction with other materials to make it strong. As I understand it it is the weave that has alot to do with it. I worked with a guy who helped build some of the first Kevlar Boats for the Coast Guard. I guess fiberglass boats are built backwards in this case the paint/epoxy is put in the mold and the Kevlar Fibers are then sprayed on or something, then the fiberglass. Kevlar isn't so much bullet proof as bullet resistant. It takes a tremendous amount of energy to pierce it so that if it does the bullet has worn down and can no longer continue on its path. That is why you have varying degrees of vests for different powers of bullets.

[Bridger]

I suspect you will have better luck with a blade designed for cutting non ferrous metals. they have harder carbide ground at more obtuse cutting angles. feed slowly.