Template cutting problems

[Joe Peacock]

I am cutting 3" x 5" templates on my new 12" x 16" VersaLaser 30 watt. Each template will have various shapes like hearts, circles, squares...etc. on them. I am cutting .062 acrylic with thin blue plastic on both sides of it. Each template needs to be engraved with the part number and company logo on them (hopefully).
If I cut with the plastic removed from either surface I get smoke stains on the surface without the plastic covering on it. If I leave the plastic cover on both surfaces then there are no smoke stains but.......I need to engrave one surface with the part number and logo so I am kind of stuck about what to do. I have the plastic elevated over the honeycomb about 1/4". I have tried a lot of power/speed/dpi combinations on the cutting and I can't escape the smoke stains.
I had a thought this evening before I left work that since there are no problems with cutting when both sides are protected by the film why not just cut out the part number too! I can always buy a sticker for the logo. I am not sure this is going to work because the space for the part number is real small and I am afraid that cutting the part number is going to get messy since the plastic covering will not vaporize and just end up being a balled up mess down in the cut out number. This is what happened when I tried to engrave with the covering still on. The logo was full of melted plastic from the protective covering.
This is a production situation and I need to develop a procedure and settings that gives the cleanest product without a lot of hassle for the operator like removing parts after cutting and then engraving them or cutting them out engraved without the protective coating on one side and then having to clean the smoke residue off somehow.
I am using 100% power and 9% speed and 1000 DPI for the cutting and 50% power and 100% speed and 1000 dpi for the engraving. Both cutting and engraving work good at these settings but to get good clean parts I have to leave the plastic on and to get good (or any) engraving I have to remove the plastic covering.
Any suggestions would be greatly appreciated.
Thanks,
Joe

[Rodne Gold]

Are you using air assist? If not do so and up the flow and pressure.

[Joe Pelonio]

Paper transfer tape, it protects from scorching and staining, engraves through it, and peels off very easily after. For some of the more stubborn materials like ABS I'll mist it with water before cutting, it still stays on but keeps it cooler.

[Joe Peacock]

Paper transfer tape, it protects from scorching and staining, engraves through it, and peels off very easily after. For some of the more stubborn materials like ABS I'll mist it with water before cutting, it still stays on but keeps it cooler.

Joe,
I thought about the transfer tape but it would have the same effect as the blue protective covering when I engrave. The letters in the logo and the part number are so small that when I peel the protective covering (or the transfer tape) off, the little bits in between the letters and part numbers that wern't rastered would have to be removed and it would take a small pair of tweezers (and a lot of time) to remove them!!
I may have to go to a label for the part number and the logo.
Thanks for your input.
Joe

[Dan Hintz]

Joe,

A quick rub with a Magic Eraser will get rid of all of the little tiny bits of left-over masking... even your finger may do the trick if they're small enough or the adhesive on the transfer tape is weak.

[Richard Rumancik]

If you don't want to pick at the individual letters, would they allow you to scribe a rectangle around the logo/part number? Apply paper mask, cut out shapes, scribe a box in graphics area (this will show on the acrylic). Then stop and weed off the rectagular paper bits while still in the laser. Then send the file (layer) with the part number & logo.

However, I have done what was suggested - it might not be as bad as you think. You will not have good results lasering acrylic (cutting or marking) with poly. Sometimes you can get the acrylic with paper masking suitable for lasering but not in every color, grade etc. in which case you need to peel the poly and remask with paper. Poly will lift off and the acrylic vapor will get underneath making a stain. Once poly lifts off an edge, it won't stay down anymore as it looses it adhesive property immediately.

[Joe Peacock]

Thanks to everybody! I will give your ideas a try.
Joe

[donald bugansky]

Joe,

If I understand your issue

I ran into the same thing doing 1/4" Christmas ornaments which had engraving on them. Here's what I did - basically I did it 2 different ways.

1) I engraved all the items on the sheet first and then covered the sheet with mask. I then ran again, this time only cutting the vectors. Pulled the mask which was very easy since the engraving was already done. I tried it with engraving with the mask on but it wasn't as clean.

2) I ordered some pin tables from Epilog which raised everything about 3 inches. I cut the same items without masking and to my amazement, it was a very clean cut. You just build the grid in Corel so you know where to place the pins so they don't interfere with your cuts.

Lastly, be careful what you use in trying to clean off the smoke residue -don't use brake fluid - (don't even ask). Look for post by Rodne Gold for what not to use for cleaning acrylic.

Hope this helps. Bugs