laser on CD

[Dave Jones]

I tried searching, but the search here says "CD" is too short. I thought I saw some posts somewhere about trying to laser engrave CDs.

Anybody tried it? Is it possible/not possible?

My brother was interested in maybe having a commercial CD made with laser etched surface instead of a silkscreened label. I thought I had read here or somewhere else that the laser would cause stress fractures on a CD, but wasn't sure. Maybe the metal layer in the CD would cause a reflection problem too.

[Joe Pelonio]

I have both engraved and cut CDs on my laser. In the case of the engraving the CD still worked fine after. In the case of cutting, obviously
not. I was surprised that there was no problem with reflection, as mirror-like as they are.

[Lee DeRaud]

Joe, I'm guessing those were CD-R's you engraved, not commercial printed-foil CD's, right? The information layer on most commercial CD's is a thin metal foil up at the top, just under the label: doesn't take much to bugger it up. On a CD-R, there's a thin layer of polycarbonate before you get to the dye layer where the bits are.

[Joe Pelonio]

Right you are Lee, they were CD R's with no label. Actually that's why they wanted me to engrave them. Never tried on a commercially mass
produced CD.

[Dave Jones]

This would be on commercial pressed CDs, in 1000+ piece batches.

One thought I had was that they could silkscreen a solid black label and then I could laser off the ink. But I think they were interested in a more subtle label with just engraved plastic surface.

As far as I know CD-Rs and pressed CDs have more in common than you would think. My understanding is that pressed CDs are injection molded polycarbonate with the pits molded into them. The pits are then coated in metal (usually aluminum) and a layer of acrylic is molded over them. That's the label side.

CD-Rs are made in a similar way except the molded surface is flat (no pits). They are then coated with a dye, and then that is coated with a metal layer (usually gold or silver). And then that is covered with a thin layer of acrylic. (label side)

Burning a CD-R changes the state of the dye so the laser, when reading the disc, reflects off the metal layer under the dye.

Of course, I could be wrong about all this.

[Joe Pelonio]

Dave,

What you'll have to do it dig out one of your disco CD's from the glove compartment or steal a Hilary Duff CD from a kid and give it a try. I'd still guess that if the surface is polycarbonate or acrylic and you don't go too deep it should work. Let us know.

[Rodne Gold]

You wont have any success with trying to engrave cds unless you do it on the inner hole edge where there is no info.
A better plan would be to laser cut the sleeve or the insert that goes into the jewel box with some design or motif.

[Lee DeRaud]

This would be on commercial pressed CDs, in 1000+ piece batches.

One thought I had was that they could silkscreen a solid black label and then I could laser off the ink. But I think they were interested in a more subtle label with just engraved plastic surface.

As far as I know CD-Rs and pressed CDs have more in common than you would think. My understanding is that pressed CDs are injection molded polycarbonate with the pits molded into them. The pits are then coated in metal (usually aluminum) and a layer of acrylic is molded over them. That's the label side.

CD-Rs are made in a similar way except the molded surface is flat (no pits). They are then coated with a dye, and then that is coated with a metal layer (usually gold or silver). And then that is covered with a thin layer of acrylic. (label side)

Burning a CD-R changes the state of the dye so the laser, when reading the disc, reflects off the metal layer under the dye.

Of course, I could be wrong about all this.We both might be wrong.:p

Your overall analysis of the construction is correct. But the impression I had is that the dye/metal layers in a CDR are located about where the bottom of the pits are in a CD, i.e. the label-side acrylic top layer is thicker on the CDR. Probably not much, but it does seem like pressed CDs are easier to damage from the label side than CDRs are. It may also have to do with the different metal used in the coating.

[Lee DeRaud]

...steal a Hilary Duff CD from a kid and give it a try.But then he'd have to actually play it to find out whether it got damaged...it's just not worth it.:eek: :cool:

[Dave Jones]

A better plan would be to laser cut the sleeve or the insert that goes into the jewel box with some design or motif.

I like that idea better myself, but I think he was wanting to go for something really unusual.

Or better yet, maybe laser engrave the jewel case itself?

[Lee DeRaud]

Or better yet, maybe laser engrave the jewel case itself?You can do it, but they seem to break easily enough as it is without weakening them with the engraving.

[Dave Jones]

Hmmm... here's another hair brain idea. How about placing a mask on the disc, engrave that, and then hit it with a quick blast from a sand blaster?

[Michael McDuffie]

I worked for a CD-ROM manufacture for 6 and a half years as a maintenance technician. I've personally shattered several thousands of CDs.

I would not do anything to damage the integrity of a disc. We had some come back that had blown up in a high speed drive, ejecting material out the front of the drive.

We did engrave a serial number on the hub, the clear central portion, with a 10 watt galvo system.

For something different, ask the replicator if they will master the image he wants onto the stamper. That way, it is molded into the disk and it looks really cool. Our mastering department didn't sell this as well as I thought they could.

Another way is to print the image with flat clear. It won't have a lot of contrast against the gloss of the lacquer but will show up when held at an angle.

The disc from the mold is about 1.19mm thick, the aluminum layer is measured in angstroms and the lacquer layer is in microns.

Michael

[Lee DeRaud]

Another way is to print the image with flat clear. It won't have a lot of contrast against the gloss of the lacquer but will show up when held at an angle.I've seen that done on a couple of commercial music discs. If your eyes aren't perfect, it's completely useless IMHO, not to mention annoying.

[Dave Jones]

Interesting suggestions. I'll pass them along.

[Michael McDuffie]

I've seen that done on a couple of commercial music discs. If your eyes aren't perfect, it's completely useless IMHO, not to mention annoying.


True, but you should see some of the really strange and indecipherable artwork that some people think looks really cool. I've no idea what they were thinking.

The art in the stamper itself looks really neat but the only time I've seen it commercially was an AOL disc about 5 or 6 years ago.

Michael

[Ray Palleschi]

I haven't tried them on a laser engraver but LightSribe makes CD's and DVD's that can be printed on using the CD/DVD writer in the computer. After you finish writing the disk, you flip it over in the drive and it prints the other side. It will print bitmaps and text but the text capability is somewhat limited. Blank Disks are available at Staples store.

I'll give it a try on our laser and post the results ASAP.

Ray Palleschi
A&R Engravers, Inc.

[Dave Jones]

Laserscribe isn't really an option for a high production CD. They are going to want to have them professionally duplicated by the thousands and I doubt I could convince them to go with CD-Rs. Engraving would already push the budget pretty high, but CD-Rs would probably raise it too high.

[Hugh Jassle]

My first post, and instead of asking for help, I am providing it... this is a first...

Have you looked into "Lightscribe" technology? This is where the laser unit in a CD-R can remove material on the label side of a CD... you burn the CD as normal, then flip it over and use their software to draw pictures on the flip side.

http://www.lightscribe.com/

It beats masking tape and a sharpie...

More Pics:
http://images.google.com/images?q=lightscribe

This would be for lower volume runs, as the media is a touch more pricey than standard CD-R media.

Hope that this helps!

-J