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David C. Smith
06-12-2008, 8:18 PM
Greetings Creekers,

I've been lurking on the creek for months now and have learned so much from all of you. My Accuris Powersharp is one of my most prized tools, and I owe my ability to make it run you all, thank you.

After a few months using the laser for personal projects, we are finally starting to take on outside work. One client is interested in creating a part for an exterior application. He liked the 1/4" Black ABS sample we cut for him but we are concerned about ABS's poor UV stability. My plastics supplier recommended Acrylic as a valid alternative but I'm worried it might be too brittle for the application.

Can anyone recommend a material that combines the strength and flexibility of ABS that is UV stable and can be cut on a 30W laser?

We have discussed painting the ABS as a last resort.

Scott Challoner
06-12-2008, 8:33 PM
You can also get high impact acrylic. I think it's also known as impact modified among other names.
I regularly cut 3/32 Lexan (Polycarbonate) with 30 watts. You can get it with a UV coating.
Given a choice, I would rather cut the acrylic.

Bill Cunningham
06-12-2008, 11:39 PM
Theres a big thread on here someplace about the pros and cons of cutting polycarbonate.. Anything that smokes that bad, and turns such a ugly shade of yellow can't be good for you :confused:

David C. Smith
06-13-2008, 7:16 AM
Yeah, I tried some polycarbonate once, and think I'll stay away.

We are looking at Corian as a possibility, how strong is it in 1/4" thickness, is it even available that thin?

Spencer Hochstetler
06-13-2008, 7:27 AM
You might have a look at Spectar UV.

http://www.eastman.com/products/producthome.asp?product=71015119&SelectorUrl=%2fProducts%2fproductSelector.htm&ListPath=%2fProducts%2fProductList.htm&sSelectorType=Generic&sCategoryName=SPECTAR+copolyester

Scott Challoner
06-13-2008, 11:10 AM
The Spectar is PETG which I haven't had much luck with. It tends to melt itself back together. Maybe with more air assist or different settings, but I don't know if anyone else has had any better luck.

I don't think you can cut even 1/4" Corian with 30 watts. Otherwise, It would probably work great.

I read all of the posts about polycarbonate and agree it isn't fun stuff to work with. I leave the mask on both sides and cut with as low power as possible. I have been experimenting with 20% power at .5% speed lately and it smokes much less. The thing with polycarbonate is it melts at around 400F but the temperature of degradation is around 715F. I'm trying to hit the window between melting and degradation. A good exhaust system is also a must.

David Fairfield
06-13-2008, 11:39 AM
I had a job making a sunshield for an outdoor industrial gauge. Their engineers left a plastic window open to sunlight which cooked the electronics inside. According to their research, black sheet rubber would outlast the entire product and was totally impervious to sunlight or weather.

I made several hundred of these shades on the laser for them. The rubber cut fine, but it was the dirtiest sootiest job I ever did, and I would be hesistant to take more rubber cutting work due to the cleanup involved.

Dave

David C. Smith
06-13-2008, 2:42 PM
Thanks for all of the help,

The client has decided to go with Black ABS which I am told has some inherent UV resistance due to the carbon content that makes it black, and we are going to paint it with Krylon Plastic Spray for good measure. Looks like it's going to be a messy weekend!

I'll let you know how it turns out.

Any ideas on doing a 2nd color logo? Since I have to paint anyway, I was playing with the idea of painting white first, then black. Then kiss cutting through the black to reveal the white logo. Would this be more or less consistent/efficient then the typical mask cut and color fill route.

Any experiences is greatly appreciated.

Thanks,
David

Bill Cunningham
06-14-2008, 9:42 PM
I had a job making a sunshield for an outdoor industrial gauge. Their engineers left a plastic window open to sunlight which cooked the electronics inside. According to their research, black sheet rubber would outlast the entire product and was totally impervious to sunlight or weather.

I made several hundred of these shades on the laser for them. The rubber cut fine, but it was the dirtiest sootiest job I ever did, and I would be hesistant to take more rubber cutting work due to the cleanup involved.

Dave

That reminds me of last summer walking by some fellows car at the marina. He (or she!) had left their Blackberry on the dashboard.. The temp outside was 95+, and the sun was beating down on it through the windshield.. No point in looking for him, the LCD was a nice shade of black already.. Probably burned the hand that picked it up. At least it wasn't his dog or kid!:eek: