Help with cutting styrene

[Thomas Wynn]

Using a M-25 to cut 1 and .5 mm styrene. I get a raised melted edge at the cut, sort of melt back. I've tried many different setting without much luck for a cleaner cut. Any tips would be great.

thanks

Thomas

[Joe Pelonio]

Stryene is soft and will do that, I know of no perfect way around it. The thicker it is the worse the melt. Your best results are low power fast speed and several passes, with moistened transfer tape on both sides,
but it won't be perfect.

[Rodne Gold]

On our 25 W mercuries when we had em , we used to cut 1mm styrene at about 10-12% speed , 100 power and 500 ppi (used it extensively for paint stencils). Air assist at max. Used the cutting grid.
We dont get raised edges or sticky melt back at all , it produces a sort of white powder in the machine if you do a lot of it. ABS on the other hand tends to do what you are getting. Check your supplier of styrene or change to a different mnfgr of the sheeting and try that.

[Joe Pelonio]

Rodne,

That's really funny, I cut a lot of ABS and have never had that problem with it. Maybe there is a great amount of difference between manufacturers/density. BTW we use the thin flexible polycarbonite for paint stencils, paint seems to pop right off after they use it and it dries on.

[Dave Jones]

Last week, I tried engraving some ABS enclosures for electronic devices and they all ended up with those raised edges around everything I tried engraving (shapes, letters, etc...) I tried lots of settings, multiple passes, etc... but each ABS box I tried had that meltback on the edges of the lasering.

[Rodne Gold]

Probably so , Joe , we have local mnfgrs here and their offerings differ albeit they supposed to be exactly the same.
I use the styrene cos its real cheap and most of the orders for these are like 200 stencils all the same sent out to various stores for instore ad type painting (like frosting on windows sort of thing) and are used a few times only , so price is an issue to the customer , Styrene is like $1.75 a sq meter here.

[Thomas Wynn]

Thanks all for the tips. I'm going to try a different supplier to start. Then on to taping/wetting.

Thomas

[Jim A. Walters]

ABS is a combination of Acrylonitrile, Butadiene, and Styrene. By adjusting the percentages of the 3 components, they can make drastic differences in the properties of the ABS. If you find an ABS that lasers or cuts like you want it to, make sure you get the manufacturers grade and specifications. Listing the grade and specifications would make a good thread for the rest of us to reference.

There are also many different properties to Styrene. Super Tuff, Hi-Impact, and different melt flow rates could affect how the Styrene cuts and engraves.

Jim Walters
former injection molder

[Ian Malings]

i have cut thousands of .015" styrene sheets for a customer and found the only times i have problems is when my honeycomb grid gets pitch buildup.
i have a 45w machine and i run full power full speed with rarely a problem.
air assist is a must with thicker material.

As for a supplier, I buy from Primex Plastics. Good prices and they manufacture their own products.

good luck

[Joe Pelonio]

Last week, I tried engraving some ABS enclosures for electronic devices and they all ended up with those raised edges around everything I tried engraving (shapes, letters, etc...) I tried lots of settings, multiple passes, etc... but each ABS box I tried had that meltback on the edges of the lasering.

I'm doing exactly that right now, 1/4" Black ABS with the "pebble" finish on one side, and it's cutting beautifully at speed 5 power 100 freq 4000 on my Epiolg 45 watts with air assist on and misted transfer tape on top.
My supplier for it it Tap Plastics (WA, OR, CA)

[Dave Jones]

I wasn't working with sheets. I was working with pre-made boxes that electronics projects get mounted in. And I wasn't cutting, I was trying to engrave text on it.

Here's a couple of pics. The text is about 1/8" tall in each pic.

The first one was text lightly engraved:

http://www.redtengu.com/images/raw/ABS_1.jpg

The second one was reverse engraved (engraved a block around the letters. THe letters themselves were not engraved):

http://www.redtengu.com/images/raw/ABS_2.jpg

You can see in both of them how there were ridges around the areas engraved.

[Mitchell Andrus]

Looks to me like the material being hit by the beam isn't leaving the surface, it's just cooking and re-depositing. Perhaps the variety of plastic you're working with is too 'gummy'.

Mitch

[Joe Pelonio]

I wasn't working with sheets. I was working with pre-made boxes that electronics projects get mounted in. And I wasn't cutting, I was trying to engrave text on it.

You can see in both of them how there were ridges around the areas engraved.

Ah, I thought you were talking about cutting. I found abs to engrave with a rough surface but no ridges. On this car stereo bezel I used outline letters:

[Dave Jones]

Since it sounds like there are a lot of variations of ABS I'm going to have to try some more tests using boxes from other manufacturers.