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Dave Kurt
04-29-2008, 12:24 PM
I just received a quote request for material I have never worked with before:

"We are interested in laser engraving simple text about 0.15” high by 1” long on a 4x12” piece of polycarbonate. Can you please quote about 200 units?"

Should I get more information? Any machine or health implications I should be aware of? Any quote amount suggestions?

Bruce Volden
04-29-2008, 12:33 PM
It engraves similar to acrylic, just don't "dwell" too long (go fast) as it will puddle?? In other words depth is hard to achieve in a single pass.

Bruce

Scott Shepherd
04-29-2008, 12:47 PM
Find out what name polycarbonate they want. Prices can be very different. I had a quote come through the other day for a sign and it said "Lexan" as the material. It was a large sign that would be mounted to the wall. I called the customer and asked why Lexan. He said "I don't know, I just picked one". I informed him that Lexan was 3 times the cost of acrylic and it's properties gave him no advantage for a sign that would be screwed to the wall.

He then said "Maybe that's why my last quote for it was so high".

It never hurts to asks about the material. It can save the customer a lot of money, which will gain you a tremendous amount of credibility when it comes to doing their work.

Richard Rumancik
04-29-2008, 1:32 PM
If it is "decorative" text you might not have good results on polycarbonate. If just a part number or identification it might be adequate. Ask for a sample to test. Acrylic lasers much better than PC as it vaporizes.

You may see some yellow/green smoke. With engraving, it might not be that noticeable. Make sure you use air assist, good exhaust and ventilation. Keep your face above the lid when possible when opening the laser so you don't breathe the fumes.

Some polycarbonates have different additives, flame retardants, surface hardeners, etc. so you need to test what you are actually going to work with. Even color can have a factor as color is generated by chemical additives.

Doug Bergstrom
04-29-2008, 2:32 PM
Lexan is a polycarb and will take a lot more force to break than acrylic. Be careful on your sign quote, you are not quoting apples to apples. There are other polycarbs that are a little less but not 3 times less than Lexan.

As other have stated when lasering polycarb watch your times. Polycarb tends to melt rather than etch.

Scott Shepherd
04-29-2008, 2:56 PM
Thanks Doug, good points. I've worked with Lexan for about 15 years or so, that's what red flagged it for the sign I quoted. Just total overkill for what they wanted to do. Imagine an oval, maybe 36" wide, 10" tall, painted on the backside and lettered, then mounted directly to the wall behind a desk. I couldn't see how it would be possible to put any amount of force on it and break it since it's against the wall.

Just no need for Lexan in that case, in my opinion.

Jack Harper
04-29-2008, 6:15 PM
Lexan is a brand of GE and actually comes in many flavors. Some are stronger than others and others are more optically clear than others. The optically clear, at all angles, are the most expensive. I use this for my tree harvester to see through without distortion and yet have full protection against flying debris or the occasional saw chain. So if they say Lexan, you are still going to need to know which Lexan.

Bill Cunningham
04-29-2008, 11:12 PM
The lexan I am familiar with, will take massive impacts, but scratches easy, and yellows outside over time..

Doug Bergstrom
04-30-2008, 1:32 PM
They now have a non yellowing version as well as fire retardent