Clean cutting with PVC on bottom

[fab3]

I recently started clean cutting with our old Mazak that has a 1500 watt PRC resonator. I have been cutting only 14ga. and thinner so far but with mixed results. We do a lot of food grade work so we have always cut our stainless with pvc on both sides (when using oxygen). As of right now I can clean cut stainless with pvc on the top and it cuts great without any problems but if it is on the bottom I get dross all over (on any thickness). Is this a power issue or possibly gas pressure? Can it be done at all? We are currently pushing 150 psi out of the head but are in the process of upgrading our system to get 250 psi.

 

[Foostrap]

Food grade stainless should not be cut with oxygen. You should you nitrogen to avoid oxidation.
When cutting with nitrogen, it is normal to have a small burr when the plastic is at the bottom. Not much you can do about that.

 

[rambynas]

I was getting better results reducing NO2 pressure from recommended 8 to 7 or 6. Try focus right in the middle of material.