Laser cutting paper question

[Brian Queen]

Has anyone been able to laser cut paper without leaving a burnt edge? I have a Rabbit 80 watt HX1290SE and whatever combination of power and speed I use I get a burnt edge. I can get it down to minimum but it’s always there. If I stack my cut sheets (which I cut one at a time) you can really see the burnt edge and it can be messy in that the carbon gets on your fingers and contaminates the white paper.
I always turn the sheet over, printed side down, as most of the burning occurs on the top side of the sheet. After cutting I apply 2” wide painters masking tape over the whole sheet and when I peel that off it picks up most of the carbon. I’ve also noticed that the amount of burning varies with different types of paper and the thicker the paper the more burning.
Since I plan on doing a lot of laser cutting of paper for some architectural origami structures I’d like to hear how other people deal with this problem.

Brian

[SkipW]

Hi Brian,

I have a similar 80w laser from WK Laser. I have only cut paper a few times but with the focus set correctly and the air assist on, I don't get any burnt edges at all. I'm using a 2", or 54mm FL lens which puts the air cone pretty close to the material for better results. Maybe that's the difference.

Are you running air also? Are your lenses and mirrors due for a cleaning by any chance? Are you using more power than is necessary?

Sorry I can't be of more help.

Skip

[rikolaser]

Dear Skip:
You are very professional with laser machines and have lots of experience! Are you the dealer or user?
Alice

[SkipW]

Dear Skip:
You are very professional with laser machines and have lots of experience! Are you the dealer or user?
Alice

Hello Alice,

Is this Alice from http://www.sukelaser.com/ ?

I'm not very professional and I have just enough experience with lasers to be dangerous. :-)

Skip

[MacGyver]

Brian,

Are you using air assist? If not, I suggest doing so. A reasonably strong gust of shop air should be adequate, but you can also try nitrogen for the nastiest of cases.

[LaserImage]

Brian,
I cut lots of paper, and tons of other stuff, with my 30 watt laser. I started with 100% speed and 5% power and just increased power by 5% until it cut. then I started 5% below that speed and increased by 1% until it cut. I use this method to determine power/speed for almost any material. Paper cuts very cleanly if you are using full speed and the least power necessary.

Gary

[rikolaser]

Dear Skip:
Yes,this is Alice from www.sukelaser.com

[rikolaser]

Dear Brian:
Did you use the air assist system when cutting? The air pump?
Alice
sukelaser@yahoo.com

[Brian Queen]

Thank you all for your responses. Laser cutting is new for me and the documentation that came with my Chinese machine is poor - you get what you pay for, in this case practically no support. If I try to vector cut at a high speed as Gary suggested the cut lines are all jagged as the head shakes as it moves from one position to another. No doubt this is due to incorrect settings which I’ve fooled around with not knowing what I was doing until I had to slow the speed down considerably which it sounds like it increases the likelihood of singed edges. I will have to try to understand the settings; does anyone have one of these Rabbit lasers? I do have the air assist if you are referring to the stream of air that pushes smoke away from the line of laser cutting.
Brian

[LaserImage]

Brian,
If the head shakes at full speed then you have some big problems. I would get that resolved first. If that's "just the way it is" then I would find the speed that it stops shaking and use that as your "100%" level. Run at that speed and reduce power until you eliminate the charring. There will be a power setting that will accomplish that result, you just need to experiment until you find it.

Gary

[SkipW]

80W laser power is not suitable to cut paper, it is too strong, and laser beam is too big. I suggest you use 40W or 25W laser to make it, at most 60W , i think, not 80W anyway, it will burn the paper/.

I cut this with my 80w LC6090 WK Laser. It is manila folder paper. It is a little thicker than standard copy paper, but no burning. I used a 54mm focal length lens, 25 power, 25 speed, and air assist. It can be done.

Skip

[LaserImage]

80W laser power is not suitable to cut paper, it is too strong, and laser beam is too big. I suggest you use 40W or 25W laser to make it, at most 60W , i think, not 80W anyway, it will burn the paper/.

That is only true on the Chinese lasers because they don't have the fine control of speed and power. Most other mainstream lasers are very suitable for paper