PEEK Plastic Cutting

[Pat Dowdel]

Does anyone have experience with cutting PEEK Plastic (PolyEtherEtherKetone)? I was approached by a small company who was planning on using a water-jet cutter but are concerned with the amount of lost (1/16th) per cut. And at $300 per square ft, they are wanting to get the most out of the product.

I do have a small 3x2 piece to test and at 20% speed/100% power on a 45w I got a lot of flare up, burn marks on the material, no smell and a slight depth of maybe 1/16th deep.

Do I keep trying at 10% with multiple passes or conceed to the water-jet.

Thanks
Patty

[James Stokes]

Patty, Let them have the waterjet people have it. If they are worried about losing the 1/16 they will not pay for your time.

[Joe Pelonio]

I will always require the MSDS for a new product, or at least ask the laser manufacturer if they know it to be safe to cut. If it's flaring up I'll try different settings but if I can't stop it I pass on the job.

This is from the MSDS for one brand of PEEK that I found, sounds OK on the emissions with no Hydrochloric acid release as in PVC, pretty much everything releases carbon monoxide and dioxide.

UNUSUAL FIRE, EXPLOSION HAZARDS: PRODUCT WILL BURN. SMOKE EMISSION IS LOW.
HAZARDOUS DECOMBUSTION PRODUCTS: CARBON MONOXIDE AND CARBON DIOXIDE.
SPECIAL FIRE FIGHTING INSTRUCTIONS: FIRE FIGHTERS AND OTHERS EXPOSED TO PRODUCTS OF COMBUSTION SHOULD WEAR FULL PROTECTIVE CLOTHING INCLUDING SELF-CONTAINED BREATHING APPARATUS. FIRE FIGHTING EQUIPMENT SHOULD BE THOROUGHLY DECONTAMINATED AFTER USE.

[Bernhard Rameder]

Hi,

a laong time ago i amde some engraving tests on PEEk, but for cutting i am sure you have to use a air compressor with a nozzle to cool the cutting edge.

[Pat Dowdel]

Invaluable advice Joe! I have decided to pass on this, I'm too much of a novice at this time. I would be sick if the flare-up damaged the lens or something else. Thanks for the input.
Patty

[Lee DeRaud]

HAZARDOUS DECOMBUSTION PRODUCTS: CARBON MONOXIDE AND CARBON DIOXIDE.
SPECIAL FIRE FIGHTING INSTRUCTIONS: FIRE FIGHTERS AND OTHERS EXPOSED TO PRODUCTS OF COMBUSTION SHOULD WEAR FULL PROTECTIVE CLOTHING INCLUDING SELF-CONTAINED BREATHING APPARATUS. FIRE FIGHTING EQUIPMENT SHOULD BE THOROUGHLY DECONTAMINATED AFTER USE.That simply Does Not Compute: obviously something else hazardous (besides CO/CO2) is coming off the stuff.

[Joe Pelonio]

That simply Does Not Compute: obviously something else hazardous (besides CO/CO2) is coming off the stuff.

Lee,

I agree, but yet I see that line all the time, it's almost like a disclaimer, better to be safe and not get sued.

Pat,

The flareups are not as likely to damage the lense, unless the flames go really high, as to melt a belt or wiring. I think you made the right decision.

[Barbara Sample]

Hello,
I just did a job for a sign company. They came in and asked me if I could cut some letters out of 1/4 inch acrylic. I said sure. and they came in with the acrylic. three of the sheets were quarter inch and they also had two sheets of 1/8 inch (some kind of acrylic) seemed like rowmark or something like it.
They put on a shiny glue tape to the backs of the 1/4 inch stuff, and on both sides of the thin stuff.

Well, I have never cut acrylic and gotten fire flareups the way this did. I was so scared of it, I never left it alone. I called them up and told them that I was having trouble, but kept on trying for them. I kept lowering the power and speed, and kept watching it. To make a long story shorter, I completed the 1/4 inch stuff, but some of the pieces didn't have that polished look to the edges. and as far as the 1/8 inch stuff, that was horrible. The heat was melting it, flaring up etc, so I got some of it done, but stopped with that one.

They called me the day after they picked up the stuff, and asked me to cut some of the ones that didn't come out nice on the edges over again, and I said yes, but that I wouldn't do it with the tape on it. They said ok, and the ones that I did over again, came out very nice.

So to all of you. If a sign company askes you to cut with a shiny sticky tape added to the back of the acrylic. Watch out for fire. I will not ever do it again. It's just not worth it to me. I would only do it without the tape for them.

Has anyone ever had a problem like this?
Barb:D

[Joe Pelonio]

Different adhesives cut differently, and sometimes it's the release liner
that causes trouble. The 3M laminating film seems to be OK, as is the
"banner tape" that's very thin, clear, and has a plain white release liner.
The 3m VHB foam tape flares a little but is thicker and it's hard to find settings that will go all the way thru it without too much power to the acrylic.

I did a small job just now for a guy's car, using acrylic carbon fiber, that had a really wierd adhesive. It was left over from a car dealer carbon fiber trim kit. The release liner was like rubber and the adhesive a thicker foamy
stuff. It flared up pretty good but it was very small so not a big deal. The acrylic carbon fiber itself came out with a nice edge though.