Laser spatter

Hello, fabricators. Boy was I wrong thinking a laser will always deliver on expectations. Currently cutting and bending 1.5mm pre-ground stainless on a trumpf fiber. While cutting holes in the piece approximately 20-30mm from the bend spatter appears, probably because of pierce. After bending the product on a press brake and removing the foil on the ground side it becomes apparent the little spatter spots get pressed between the punch and die and become pimples on the outside of the part ruining the finish. Have you encountered laser spatter and what you can do to prevent it without slowing the machine down? Are there anti-spatter sprays like those used in MIG welding and do they work?

Best regards.

Besides the obvious optimization of the laser cutting process. Are you using a urethane die film between you work-piece and lower die? It might also provide some improvement.

Clean the bed bars on the laser but stainless is a bear to get realy clean, a very thin coat of anti splatter on the bottom of the sheet is the best we ever found, but its gotta be real thin and a mist, think spray gun fine, just enough to do the job and no more or you bugger up the cutting. In some ways its what makes stainless the worst stuff to laser cut.

Cleaning the bed bars is not practical because after two days it's like they haven't been cleaned at all and they are full of deposits again. What spray do you use? @jmullett when we bend them on a press brake we do, however sometimes we bend them on a folding machine. I've been also looking at copper slats at 85$/piece. Let's say there are 50 in a table and this particular laser has two tables meaning 8500$ just for slats, not accounting eventual downtime for installing them and since I haven't seen anyone using copper slats makes me wonder if they are worth it. Also, like 6 grand for a slag removal tool.

^ No cleaning the bed bars off is what you have to do don't have to be spotless, but you don't want any real big chunks - large masses. Just go over them with a chipping hammer. You need that molten spray to go down into the bed, not get bounced off crap back onto the bottom of the sheet. Also greatly helps to cut your own slats and have the points as pointy as possible and further apart and also as few a points as you can get away with, if your cutting big bits, you can easily remove 2 out of every 3 slats and just a point every say 6". Equally if your only doing thin sheet, make the points a lot steeper than the typical 90 degree saw tooth patten and make the gullets a bit deeper, only cut them in 2-3mm thick material too.

Am not a believer in copper slats, yeah there more resistant to the metal spray and beam damage especially on a co2, but that spray bouncing back onto the sheet is the real issue.

With 2 beds if your cutting mixed work its not all wrong to set them up with differing slats and be selective as to what work gets cut on which if your doing mixed stuff.

If you want quality cutting off a laser you have to get the basics right and that means frequent bed bar cleaning and slats to suit your work and even possibly changeing them from one type to anouther to suit your cutting. Way too many laser places are shit because all they focus on is through put and rely on the big spend on the laser to make great parts and fail on the basics.

We use to just use a water thinable anti splatter, its not perfect, but it sure makes part clean up a lot lot easier.

Thank you for your comprehensive answer. We'll start by cleaning the bed more often while the machine cuts on the other table, spraying the bed and parts with thin film of anti-spatter and see how it will affect the product. Setting apart the slats is out of question I think because from time to time the need to cut 10-12mm appears and the table should be able to support the heavy sheet, cutting new ones with acute angles is something we can also try.

Change your pierce.

We routinely cut 12 gauge stainless on our 20 year old CO2 laser and even when piercing over a slat we never get any spatter on the top or bottom of the sheet, unless our machine is cutting bad.

Are you saying the foil is on the top? And spatter gets blown under the foil during pierce?