Suggestions for a Plastic Material

[Tim Goldstein]

Need some suggestions for a plastic material that is all the following:
0.020" - 0.040" thick
Rigid
Laser cuttable & friendly
resistant to oils and fluids that would be around a metal cutting mill and lathe
Reasonable cost so nothing exotic

I know PVC is out, but any suggests as to what is in? I am thinking no on acrylic because a lot of chemicals/oils/etc make it craze and crack.

Thanks in advance,

[Joe Pelonio]

Both ABS and Polycarbonate should suit the bill, and are approved by
Epilog as laser cuttable. Cutting ABS does make a stink, and cutting Polycarbonate is smoky (yellow) though. You could also use a high pressure laminate, such as Wilsonart or Formica. Takes more power and less speed but does cut smoothly.

[Richard Rumancik]

Is this for a machine guard? If so you would probably want clear. That probably rules out ABS. Polycarbonate will laser cut in thin gauges but it leaves a charred edge that you need to sand down a bit. It is not very chemical resistant. Some people get pretty alarmed when they see the green-yellow smoke during laser cutting. Use proper ventilation.

Take a look at PET-G. You don't say what you are making - PET-G will not cut with a beautiful edge like acrylic, but it will laser cut. The edge turns whitish and is somewhat raised. If this is okay get a scrap and experiment with it before buying a sheet.

It is probably fine with machine oils but if you get a sample you can immerse and see the effect.

[Joe Pelonio]

Is this for a machine guard? If so you would probably want clear. That probably rules out ABS. Polycarbonate will laser cut in thin gauges but it leaves a charred edge that you need to sand down a bit. It is not very chemical resistant. Some people get pretty alarmed when they see the green-yellow smoke during laser cutting. Use proper ventilation.


I've gotten nice smooth edges with 1/8" and below, only found the charred edges on 1/4". Could be an issue of the settings? And yes, the yellow smoke is what made me contact Epilog to be sure it was OK. Run it at night so your neighbors don't see it or they'll no doubt call the fire department.

[Jim A. Walters]

Here is a chemical resistance chart for polycarbonate from K-Mac Plastics.

http://k-mac-plastics.com/data%20sheets/polycarbonate_chemical_resistance.htm

Maybe consider Polyethylene or Polypropylene? Different grades will have different stiffness properties. If it was .020 or .040" I would think you could cut it.

[Kim Vellore]

How about Delrin?

Kim

[Martin Reynolds]

Delrin is about the best combination of stiffness and strength that you will get in that thickness - but of course, it is not clear. The black type cuts very nicely.

Acrylic is stiff and clear, but fragile in that thickness.

PETG and polycarbonate are tough and clear, but relatively flexible. PETG and polycarbonate bith cut well at that thickness, but PETG will give a nicer edge.

[Scott Loven]

How about phenolic or Epoxy-glass?

[Michael Kowalczyk]

Need some suggestions for a plastic material that is all the following:
0.020" - 0.040" thick
Rigid
Laser cuttable & friendly
resistant to oils and fluids that would be around a metal cutting mill and lathe
Reasonable cost so nothing exotic

I know PVC is out, but any suggests as to what is in? I am thinking no on acrylic because a lot of chemicals/oils/etc make it craze and crack.

Thanks in advance,

Tim how about lexan?
I have played around with some thin stock. Takes more power to cut but is almost indestructible.

[Brian Robison]

I haven't tried to laser cut it yet but Polypropylene and Polyethylene are the most chemical resistant. Hope this helps.

[Tim Goldstein]

Thanks for all the suggestions. I should have said that it does not have to be clear. It is protecting gears and such on the back side of a lathe. Tried the suggestion of Delrin and like the way it works out. Like the idea of phenolic as the linen fill stuff should cut nice. But have not laid my hands on some to try.

Delrin version is mailing out to the customer for evaluation.

[Martin Reynolds]

I'd stick with the Delrin, it is just about perfect for this application.