Milling polypropylene opaque colored sheet thickness 0.5 mm


When I mill polypropylene sheets, (Polypropylene opaque colored sheet thickness 0.5 mm × 3), with a flat U Single Flute bit (1.5mm cutting diameter), even if I have a dust collection system (that works perfectly for the other materials), I get a lot of tiny residues that do not get collected and most of the parts where the cut has been made have this problem:

Any suggestions as how to avoid this and get a clean cut? Is there a better bit to use?


material this thin? A vinyl cutter would probably work better. Or a laser cutter if that specific material is safe. Maybe make a pen holder, trace the art and then cut with an exacto knife.

Vinyl Cutter doesn’t work. I tried. Too dense of a material.

Tracing with a pen, and then using an exacto knife is not as exact. I need intrincate cuts. And, in my experiencie, an exacto knife is not as exact ;).

But thanks anyway :).

Looks like static.

Hi Martin,

We cut .020 (.5mm) polystyrene on a vinyl plotter all the time for making stencils. If you use a 60 degree blade and all the force the machine will give, you should at least be able to get it to the point that you can pop out the pieces. Sometimes we’ll run it with a double cut (two of the shapes right on top of each other) if we’re really worried about getting intricate pieces out.

We’ve tried routing it, but ran into the same issue you had. little pieces that flew everywhere because of static. A light mist of soapy water helped, but didn’t alleviate it to the point where we stopped using the plotter.

edit I just remembered that Donek has a drag knife for CNCs- that might be perfect for what you’re trying to do.

I see, thanks. That is what I am using it for: Stencyls. But I also wanted to cut some squares for a card-like setup.

What is weird is that I have a dust collection system, but it seems not to catch most of them. Static force must be strong…

Any way, in this photo:


The problem is not static, because those wire-chips that you see on the edge are actually attatched to the material .

I don’t have access to a high-pressure plotter. I just have a small Cameo for Vinyls and not so thick materials.

Thanks for the link, I will check it out!

You should check out a drag knife.