Minimizing Hazing and Dust When Cutting Styrene

[Doug Fisher]

I have read the old threads in the forum and just wondered if anyone had come up with a new method to minimize the dust and hazing when cutting black styrene (HIPS) in .020" and .040". I cut some fairly large pieces in fairly large quantities so I would like to avoid the expense of release paper if possible

I have tried high speed with lowest power required to cut. Both full air assist and down to almost no air assist. I realize the underside is probably always going to have marks due to the trapped heat/gasses but it would be great if the top side could come out unblemished. At this point, it seems I am getting some heat damage (glossing and A in the pictures below) plus hazing clouds (B in the pictures below). Masking tape worked but is a real hassle even with the 2-3 inch wide version. Wetted newspaper worked and had faster cleanup but application was slow and subject to bubbles (fast "cleanup" though).

If release paper is the best option, I would appreciate a recommendation. Will a low tack version work with styrene? It has got to reliably form a seal without bubbles.

Thanks in advance.

At "A", the matte finish has been turned to gloss. At "B", there is lots of haze.

Styrene Glossing and Hazing 1.JPG

Same test piece but at a different light angle
Styrene Glossing and Hazing 2.JPG

This white piece of paper was used as a mask. You can see the black soot that is being fuzed to the styrene during cutting. Acetone and MEK won't wipe it off.
Styrene Glossing and Hazing 3.JPG

[Bill George]

I would experiment with your exhaust air flow and are you cutting on a honeycomb where air can be pulled down?

[Scott Shepherd]

Only way I've found is to take multiple light cuts instead of one pass to get through. Of course, with that, and your shapes (straight line), you could go quite fast.

[Doug Fisher]

Thanks for the replies.

Yes, Bill, I am using a honeycomb table. I was wondering about exhaust but I don't really have any way to modify the flow/direction.

Scott, I will try the multiple pass method. Those were just test cuts so my design is quite a bit more complex with curves and relatively small holes so we will see how fast I can actually run the cutting. Maybe it will still be faster in the end if I don't have to deal with the masking.

[Tony Lenkic]

Doug,

Premask transfer tape is not to expensive. Roll of 100 yards by 12" wide can be found for 40 under 50.00 bucks. this roll will cover lots of work pieces.

[Bert Kemp]

my laser has a flip door on the 6" exhaust hole on the back. I can move the door for top or bottom air extraction . Maybe you could make something up. looks simple enough.

Thanks for the replies.

Yes, Bill, I am using a honeycomb table. I was wondering about exhaust but I don't really have any way to modify the flow/direction.

Scott, I will try the multiple pass method. Those were just test cuts so my design is quite a bit more complex with curves and relatively small holes so we will see how fast I can actually run the cutting. Maybe it will still be faster in the end if I don't have to deal with the masking.

[Gene Uselman]

Bert I would love to see a pict of that feature, I am working on the extraction on my machine and that sounds like a nice feature. Thanks Gene

[Joe Pelonio]

Doug,

Premask transfer tape is not to expensive. Roll of 100 yards by 12" wide can be found for 40 under 50.00 bucks. this roll will cover lots of work pieces.

I agree, cheap and a great tool that you must have. I always have a roll of 12". Check your air assist, I cut black abs and it will scorch at 25lbs. of air assist, at 40 it cuts nice and clean with transfer tape on the top, textured surface. Because of the texture I use high tack.

[Kev Williams]

One neat thing my LS900 has, but I've never used, is an exhaust hose attachment that attaches to the gantry right behind the lens-
9e1.jpg
the other end goes into a tube at the back of the machine...
9e2.jpg9e3.jpg
the other end of this tube right against a flat plate on the exhaust blast door,
9e4.jpg
which when closed, exposes a hole that fits directly below the tube (I left part of the hole showing)
9e5.jpg
Now, all of the blower's vacuum is focused on this tube, AND to the hole in the table next to the piece of Rowmark...
9e6.jpg
fed by this hose...
9e7.jpg
When used with the cutting table designed for this machine, the table hole draws all of the cutting smoke from below the cut,
and the lens hose sucks up all the smoke at the surface of the cut. Note that I'm missing a bracket that holds the tube and funnel in the correct position, I have it hung with a rubber band

I set this up just for these pics, and gave it a go, and it REALLY sucks up the smoke! I'm half tempted to try cutting some un-taped Rowmark just to see if it will reduce the edge soot and such...
I've never used it because (a) I don't have the cutting table to make use of the table draw, and (b) all the cutting I ever do is just 1/16" Rowmark pieces, and the normal exhaust works just fine.

I mention all this because I also connect plain old wet-dry vac's up to 1/2" clear rubber hoses to suck up engraving chips all the time around here. I don't think it would be all that hard to rig up a bracket that would hold one of these hoses near the point of cut, and run the other end to a vac-- use a vac with a blow side, that you can exhaust outdoors.

Cheesy? who cares, as long as it works! (my whole operation is 'cheese')

[Bert Kemp]

Bert I would love to see a pict of that feature, I am working on the extraction on my machine and that sounds like a nice feature. Thanks Gene

ok I'll get on that.Yikes now I have to clean my vents LOL IMG_20170612_194437100 - Copy.jpgIMG_20170612_194444081 (Copy).jpgIMG_20170612_194448230 (Copy).jpgIMG_20170612_194452459 (Copy).jpgIMG_20170612_194501127 (Copy).jpgas you can see easy to make and controls where the exhaust draws from . top , bottom or both.

[Dave Sheldrake]

2mm exit hole on the cone, 25 psi of air

3mm standoff from the job = flawless cuts in styrene