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Thread: 352nm UV laser: will it cut scotch tape?

  1. #11
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    Hi Viktor,

    Quote Originally Posted by VDX View Post
    ... I've done cardboard ablating, engraving and cutting with blue 2W, 3.5W and 6W laserdiodes or 85Watts CW- or 20Watts pulsed (20W averaged from 10kW pulse peak power) fiberlasers - the more power, the faster.
    Speaking about the 20W pulsed fiber laser: which wavelength? I did try using 1065nm 20W Q-switched fiberlaser to no availability. It would not cut tape or paper at all. At best, I could burn paper (very slowly).

    Same question about laser diodes: which wavelength?

    Also, if you happen to have any photos of the results, I would be very grateful if you can post them.

    What's another problem with "undefined" materials -- if you cut through, theres's noting, what will stop the beam from burning the space inside too!!
    This is true. The hope is to use camera perception and only cut where it still needs it; not guaranteed to work, of course.

  2. #12
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    IF THAT IS aLL your fiberlaser did at 20 watts, it sounds like it was not programmed correctly, set up properly, damaged, or driven with the wrong signal. Was there an F1 lens in front of the fiber to focus the light?

    STEVE
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  3. #13
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    Quote Originally Posted by mixedgas View Post
    IF THAT IS aLL your fiberlaser did at 20 watts, it sounds like it was not programmed correctly, set up properly, damaged, or driven with the wrong signal. Was there an F1 lens in front of the fiber to focus the light?
    The fiber laser itself is fine; I have no problems engraving steel / aluminum / brass.

    As for parameters, it's certainly possible that I just failed to find the right combination of frequency / power / speed. If anyone has a hint, I will very much appreciate it.

  4. #14
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    ... the 2W to 6W laserdiodes were blue 445nm-diodes, focussed on spot diameters around 0,1mm.

    The fiberlasers were at 1064nm and cuts coloured/dark paper or adhesives without problems, but could be problematic with white or transparent materials.

    For samples/images -- read through this thread pretty big thread: https://photonlexicon.com/forums/sho...ng-and-marking

    Viktor
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  5. #15
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    Quote Originally Posted by VDX View Post
    ... the 2W to 6W laserdiodes were blue 445nm-diodes, focussed on spot diameters around 0,1mm.
    Got it, thanks! These 445nm diode modules are amazing.

    The fiberlasers were at 1064nm and cuts coloured/dark paper or adhesives without problems, but could be problematic with white or transparent materials.
    Yeah. In my case, there are three primary materials:

    - corrugated carton; light brown. I kind of able to get through it with my fiber laser, but it mostly burns than ablates.
    - thermal shipping labels. Bright white. It's extremely hard to even make a mark on it. And if going with full power / very slow, it starts a fire from under paper.
    - scotch tape. Transparent for anything except UV and far-IR.

    So, for my experiment I either need to get a galvo-driven CO2 laser (preferably pulsed, but I have no idea actually) or a true UV laser, like these 352nm lasers that can be found on eBay: https://www.ebay.com/itm/3W-UV-Laser...r/114124665349

    In both cases, it does not seem wise spending money without better understanding if my goal is even feasible with these options, or if I am missing something completely.

    For samples/images -- read through this thread pretty big thread: https://photonlexicon.com/forums/sho...ng-and-marking
    That's a great thread! I just spent almost an hour reading it / clicking on the links. You have done some impressive art, Viktor! I am also impressed that you designed your own driver for a galvo head.

    By the way, which laser did you use for this experiment? https://vimeo.com/324298550

  6. #16
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    Quote Originally Posted by fuzzy View Post
    By the way, which laser did you use for this experiment? https://vimeo.com/324298550
    ... this was a 200W@975nm laserdiode, with some microsecond long pulses (IIRC 3µs), at below 100 Watts of power, on a spot of maybe 0.2mm.

    Here its burning through a tile - https://www.youtube.com/watch?v=nVsZ07bP-AM

    Have some of them to combine up to 1.2kW on a 0.4mm-spot

    ---

    For the CO2-route -- I've sourced a galvo-head and optics for the CO2 wavelength - and a small RF-CO2-laser with 10Watts ... want to build a galvo-CNC-combi with them (100x100mm galvo on a 500x500mm CNC) - but could need some months until running ...

    Viktor
    Aufruf zum Projekt "Müll-freie Meere" - https://reprap.org/forum/list.php?426
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  7. #17
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    Quote Originally Posted by VDX View Post
    ... this was a 200W@975nm laserdiode, with some microsecond long pulses (IIRC 3µs), at below 100 Watts of power, on a spot of maybe 0.2mm.

    Here its burning through a tile - https://www.youtube.com/watch?v=nVsZ07bP-AM

    Have some of them to combine up to 1.2kW on a 0.4mm-spot
    Looks terrific!

    For the CO2-route -- I've sourced a galvo-head and optics for the CO2 wavelength - and a small RF-CO2-laser with 10Watts ... want to build a galvo-CNC-combi with them (100x100mm galvo on a 500x500mm CNC) - but could need some months until running ...
    galvo + CNC is a great combo. Recently, an even better one has become somewhat affordable: laser + 6 degrees-of-freedom robot arm. That allows to go beyond x/y/z and beyond flat objects, but more heavy on software.

    galvo + XArm6 is the route I am currently seriously considering, so that I can cut boxes from all sides.

  8. #18
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    To the main topic: I just bought some cheap 352nm torchlight and will be testing if scotch tape is transparent at this wavelength.

    If it's fully transparent at 352nm, my only remaining option would be galvo CO2.

    If it's absorbing a reasonable amount, I will consider buying a galvo 352nm laser.

    Will update this thread when I have the torchlight. Ideas on how to measure absorbtion are welcome. As a reminder: I am a total noob in optics;

  9. #19
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    ... some sort of sensor/detector (e.g. camera, photo-transistor or some "sensitive" material for "burning tests"), measure signal with direct illumination an then put your test-sheet between -- and look, if the signal lowers significantly

    Viktor
    Aufruf zum Projekt "Müll-freie Meere" - https://reprap.org/forum/list.php?426
    Call for the project "garbage-free seas" - https://reprap.org/forum/list.php?425

  10. #20
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    Quote Originally Posted by VDX View Post
    ... some sort of sensor/detector (e.g. camera, photo-transistor or some "sensitive" material for "burning tests"), measure signal with direct illumination an then put your test-sheet between -- and look, if the signal lowers significantly

    Viktor
    Makes sense, thanks. I will try to go with a camera module that allows for fixed exposure and then integrate across the frame.

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