Another Plastic-cutting Question

[Lee DeRaud]

Several questions actually...
1. Is Lexan polycarbonate "laser-safe"? (As in no toxic fumes etc)
2. Assuming the answer to #1 is 'yes", can Lexan be cut with a 25W laser?

3. Same questions for the UHMW plastic jig stock such as http://www.rockler.com/ecom7/product_details.cfm?offerings_id=1580&filter=UHMW
(I have a bad feeling there is Teflon involved here, but can't be sure. Some of the hits on Google describe it as "polyethylene", but I've also seen Teflon descibed that way. Note: I'm a software geek, not a polymer chemist.)

[rich shepard]

You asked Is Lexan polycarbonate "laser-safe"?
Can't say if it's safe or not but can say it will engrave but don't try to cut the stuff. I tried a peice just to see how it would do and as it started to cut it just started to burn, as my rep said when I told him "that's why the top is Lexan".
rich

[Brent Brod]

Generally, the acronym UHMW is used in conjunction with polyethylene in the plastics business. It means "ultra high molecular weight" and means it is denser and more rigid than LD (low density) polyethylene that is typically used for things like trash bags.

I expect the material you are looking at is polyethylene. Teflon is Dupont's brand of PTFE (poly tetra floro-ethylene). Perhaps you may have confused PTFE with UHMW at some point? PTFE is significantly more expensive in similar stock as you can see here (http://www.thomasregister.com/olc/SmartCat.aspx?az=24229601&template=http://www.fluoropolymerproducts.com/temp.htm&advancedsearch=no&header=PTFE+Plate:+.500%22+%281/2%22%29&backlink=http://www.fluoropolymerproducts.com/molded.htm&type=list_order&sort=list&stripecolor=99ccff&show=part_number+part_name+list_price+unit_measure&ptno=VS1%2F2X12A+VS1%2F2X12B+VS1%2F2X12C+VS1%2F2X1 2D+VS1%2F2X24A+VS1%2F2X24B+VS1%2F2X24C+VS1%2F2X36A +VS1%2F2X36B+VS1%2F2X48).

I'm no polymer chemist either, but I stayed at a Holiday Inn Express last night :)


3. Same questions for the UHMW plastic jig stock such as http://www.rockler.com/ecom7/product_details.cfm?offerings_id=1580&filter=UHMW
(I have a bad feeling there is Teflon involved here, but can't be sure. Some of the hits on Google describe it as "polyethylene", but I've also seen Teflon descibed that way. Note: I'm a software geek, not a polymer chemist.)

[Michael McDuffie]

Lee,
I've tried cutting polycarbonite and it just burns. When I worked for a CD pressing facility, we used a 10w galvo system to put a serial number on each disc and it worked quite well. In fact thats what sent me down the path toward laser ownership.

I've tried some of the dense white plastics and they don't cut well at all. There is a problem with remelt, meaning that the cut edges rebond, making a mess.

Teflon will probably be the same with the added problem of a nasty chemical release.

Vinyl and things with PVC as ingredients should also be avoided. The acid released when these are cut will damage your machine. I've got a ruler I can no longer read and the table springs are quite rusted on my machine.

Michael