Help with PVC covered SS

[sabjr]

We are tring to cut 3/16" SS with a PVC cover that says "for laser cutting". If we remove the pvc we get a better cut. Also, is it possible to get a dross free edge everytime? Can anyone help me? My machine is a 4K Mazak(only 2 months old)
Thanks

 

[QSF]

MOST GENERALLY WHEN I AM CUTTING STAINLESS WITH A PVC COATING, I WILL CUT THRU THE ENTIRE PVC FIRST (WITH AN ETCH PROGRAM) BEFORE CUTTING THROUGH THE STAINLESS. I HAVE NOT YET USED THE LASER GRADE PVC ON STAINLESS, WHICH SOUNDS LIKE WHAT YOU ARE DESCRIBING, BUT I BELEIVE YOU SHOULD PROBABLY CUT THRU IT FIRST ALSO.
AS FAR AS YOUR CUT WITH DROSS ON IT...WITH A 4K LASER IT SHOULD BE CUTTING LIKE A HOT KNIFE THRU BUTTER...

Gary L. Ellis Jr.

 

[scottyfireman]

i run a Trumpf L6030 4000watt on this machine i have process called vaporizing which i can use to do this it is basicly the same settings as the marking (etich) but with the head at a higher stand off and more speed. This works well for us. As far as the dross goes yes you should be processing this material with a very smooth and dross free cut. check the nitrogen pressure try adjusting that on my machine on .187 ss i run at about 16to18bar pressure also it is impertive on stainless for the machine to be level have a near perfect nozzle allignment and correct focus. Feel free to e-mail me at any time if you have any questions. I have been operating this machine 2years now.

 

[chadxyz]

Try this, use a large orifice nozzle(2.5 to 3 mm) and a 7.5 focal lens. Take the focus 2 to 3 mm below the nozzle. To get rid of the PVC coating run your parts with the laser head anywhere from 4 to 7 inches above the sheet. Use lower power (500 to 1000 watts) and higher pressure (200 psi Nitrogen ) gas. Your mileage may vary on speed, but what you are looking for is about a 5 to 8 mm removal of PVC coating. However, you need to watch out for reflections. The more power used = higher intensity reflections. This can melt nozzles or have other nasty side-effects. So you should check your nozzle through out the process, watch out for overheating components. Once you have removed the coating you should be able to cut normally. Usually I run the standoff very close (> .5 mm) , turn up the gas (350 psi), and I can achieve clean cuts in 3/16" S.S. at about 2m/min with a 3500W laser. Hope this helps.

 

[fredlai]

Sabjr: Try etch the PVC first and then cut.We have a 3200W Trump and it cuts beautifully on thin gauage material without etching.

 

[Co2Laser]

SABJR:

Are you sure that that is "laser vinyl"? All the laser vinyl I use has zero adverse effects on my cut quality or speeds and feeds. While etching is a solution, it is expensive to run the program 2 times. Do a little more research with your material supplier, you would be surprised what kind of garbage they try to push on us.

Or, if you're desperate, mirror your part in CAD, and cut it with the vinyl opposite the way you're cutting it now. Before "laser vinyl" I would cut my material vinyl side down.

Good Luck