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I am curious to know if any screen printers have tried using a CNC laser engraving machine to fuse the screen mesh together with heat in areas where it should be blocked out, instead of the typical methods involving photo-emulsion? My understanding is that the majority of screen printing mesh is made from woven nylon, and nylon is easily heat-welded. A laser engraver should be able to handle this task, with the right adjustment of output power etc.

Is this idea worth pursuing?

  • I suspect that simply trying to fuse the threads is going to warp the warp and weft. However there is such a thing as laser-welding of fabrics, and I also suspect one might be able to replace the standard photo emulsions with a UV-laser and a UV-curing varnish or ink. (the standard emulsions are typically very slow-curing; not very UV sensitive). – Yorik Jan 10 '17 at 22:06
  • Where i live laser engraving is charged by square centimeter so, if this works, it could be a lot more expensive than the traditional process. – Lucian Jan 10 '17 at 22:14
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I've actually tried this.

I worked from 2008-2010 as one of the primary Laser Technicians at the Gulfstream Center at Savannah College of Art and Design. I would operate and maintain the Laser for student work requests. I was asked on a few occasions to try this out on some pre-stretched screen.

We ruined a few screens getting the technique down to something that would work. Ultimately, the student decided that the process was too labor intensive to work for their purposes.

There are two primary modes for the laser I worked with:

  • One was a vector mode that would follow a path from a vector file. Since the laser would follow each path in the design (Engraving or cutting), this method could take a very long time to recreate complicated designs.

  • The other mode was a raster mode where the laser would track left
    to right etching the design from the top down in rows about one
    millimeter at a time. This was the setting that ultimately worked for their silkscreen.

Additionally, I had found that the actual engraving surface gets hot enough to warp thin and fragile materials - so I masked it (you could use Frisket, contact paper or even blue painter's tape) and avoided the issue of heat warping.

To answer the question - yes, it's possible (depending on how well acquainted you are with the machine's settings) but It might not be worth perusing based on your individual needs.

Edit Trying to recall, I seem to remember now that what wound up working best was a hybrid of the two - a simple vector outline around the edge of the shapes before rastering made a very smooth, clean edge to constrain the material when heated by the laser raster process. IIRC, rastering alone left a "pixellated" edge as a result of the characteristics of the material.

I'd like to reiterate that this could only have been done during the quiet season (not midterms or finals) and likely took 24+ hours of work and testing to determine with my solid knowledge base and experience.

  • Well basically you proved my speculation, thanks for sharing. The idea that you'd use a low every setting with laser on the photo polymer is interesting though. Not necessarily worth the time and effort but still – joojaa Jan 11 '17 at 17:33
  • Great. I'm emboldened by your successes. For a while now, I've been wanting a good excuse to build a small CNC laser engraver using the diode from a Blu-Ray writer. Since this can burn/engrave into wood and can cut vinyl clean through, I think it should be quite possible to use it for "engraving" into screen mesh. – cathode Jan 12 '17 at 1:58
  • There's a wealth of things you can do with even a low-powered engraver (given enough time and ingenuity) . The substrates you mentioned are definitely great options. Formica engraves fantastically and holds a great edge if you can get a big enough laser to cut through it - you can do some amazing engraved inlays. It goes without saying, but whenever working with a laser make certain you take the following precautions: Eye protection, Proper Ventilation and a fire suppressant system that doesn't conflict with ventilation (I learned that the hard way). – Joshjurg Jan 12 '17 at 14:14
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Having been a couple of years in a factory that cutted sheet metal by laser, I must say that scanning over an silk screen would be nonprofitable work to a machine which is designed to split steel. You can cover maybe one square centimeter at the same cost that is needed for one meter long slit.

A specially constructed low power machine would be a better choice - something that can splice only thin plastics and that machine just now hasn't something to cut. To increase the speed some unfousing should be possible to be able to have larger spot. Then there' a need for the software for this, too.

If ordinary pretensioned screen is used, irreversible streching when the screen is melted can be a problem. I believe that after 2 seconds your screen looks out anything but a perfect plane. I have no idea, how the screen can be planar enough when not uder a tension.

Of course it can be under a glass and pressed against a rigid plane. But the glass can absorb the laser totally and both surfaces can eat the heat in case the laser happens to be a visible wavelegth one.

Maybe you find a partner who lets you put your screen into his laser cutter. Testing reveals.

To see, how the screen behaves when melted needs no laser. Any heating, if controlled, can answer.

Assuming that the screen looses its shape as soon as it's melted, it's still possible that some at lower temperature fluid enough plastic material can clog the screen as wanted. Or laser makes the inserted material non-soluble. These both seem to be like a 2D version of 3D printer.

Etching by laser cutter probably can be used to expose the photosensitive coating on the screen. No need to be stucked to small sizes. That I also see worthy enough to be tested.

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This reply is very late but as a warning please do not lasercut vinyl as cathode mentioned above.

Even with proper ventilation the fumes produced are dangerous to breathe and very harmful to the lasercutter itself!

There are some vinyls that are lasercutter safe but they will be marked as such.

  • Welcome! Can you please explain, what you mean with above, for example by specifing the user you mean? – Mensch Dec 28 '18 at 21:41
  • The question is about welding, not cutting. If I use a candle to bend a small piece of plastic or my hot-air-gun to shape book-stands from sheet-plexi, then the just melting temperatures do not produce any fumes at all. There will be sets of parameters for testing, but the final production (if it can be done) will probably need to stay well below "fumes level". – Martin Zaske Dec 29 '18 at 8:45

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