Vector cutting anything black

[Jiten Patel]

Hey guys. Hope 2011 is treating you well.

Quick question about cutting things that are black. Now my galvo cuts card like butter. 1 or 2 very fast passes is all it takes. But for the first time i tried black card and it took 8-9 fast passes. Just wouldnt cut through. It ended up warping the card so I got double cut lines, which ruined the card stock.

I also have trouble cutting through some thick matt board with was black.

Do you think it's just the material, or it is in fact the colour that is affecting the cut?

[Mike Null]

Jit

Not having any experience with your type of machine I can only guess but I find that I need to slow my cutting speed for black engraver's plastic. Perhaps slowing your speed might help.

[Frank Corker]

Jit I think it must have something to do with the makeup of the card. Possibly the material itself is more robust as a result of the use of dyes to make it that colour. If they are all from the same supplier then it must be that. I don't see how the colour itself would affect the laser beam, if it does than other darker card (not black but say dark blue) would also have the same issues. With a regular laser cutting through material relies on the frequency settings, wood takes less than acrylic, if you cut wood with acrylic settings you end up with a very charred piece, if you cut acrylic with a wood setting you end up with heavy striations.

[Jiten Patel]

Frank,

Thanks for that. The black card belongs to a collection which has many colours and they cut just fine. Even dark blue. So I'm guessing it is in fact the die or the make up of the card. I will try playing around with the frequency and see what happens.

[David Fairfield]

Agree with Frank, probably something to do with the chemical make up of the dye. I imagine black could have a high carbon content. I failed High School Chemistry (actually was thrown out by the teacher:o) but I figure since carbon is whats left after you burn something, carbon itself probably more burn resistant than other dyes.

Dave

[Richard Rumancik]

This is an unexpected result as usually black will absorb the laser energy better than light colors. Ask the manufacturer what they are using to create the black pigmentation. It could be that they are using an "iron oxide black" pigment which may reduce the speed at which it can be cut. Just a guess. Does it spark more than the other papers? Carbon black or iron oxide might increase sparking when cut. In any event I think you are going to have to search for a different paper that uses an alternate pigmentation.

[Robert Walters]

Jit,

You just got a lemon galvo is all. I'll do YOU a favor and take it off your hands for $20.

I was always under the impression the black absorbs all light (depending on the wavelength),
but if it's due to the pigment you might try lower power and slower speed and see if that does anything.

[Dan Hintz]

I was always under the impression the black absorbs all light (depending on the wavelength)
All visible wavelengths, but the laser is at the near-IR end of the spectrum (hence its inability to do much damage to metal).

[George D Gabert]

Jit

Could you see if you can send a sample of each paper color to Fank or someone else on that side of the pond, to test cut each sample to see if there is a difference on a x-y machine.

GDG

[Jiten Patel]

I've tried slower, and its too slow for the level of detail and I end up with just a pile of black ash rather than card. It does spark, but saying that, I've got a few other colours which spark quite a lot too, but they cut through like butter. It is much brighter though, so bright that it hurts to look at it.

Robert, call it 30 bucks and we got a deal! lol

I dont mind sending a sample to some over here.....just send me a message with contact details and i will send out a few samples from the same family of card, in a few different colours.

Bloody annoying though. I mean matt board (mount board here in the UK) in black took 50 passes to cut through. And some black boxes I use for packaging took 30-35 pases which is crazy as say pink card take 1-2 passes to go through. Considering the board is 5 times as think, one would assume 10 passes tops. Hopefully no one will order anything that is black.

[Michael Hunter]

Jiten

I would be happy to have some samples and confirm (or not) your findings. Contact details via "Friends" link.

There must be more than one place making mount board - it is probably worth trying to get some samples from other suppliers to see if they perform better.