Author Topic: Led exposure unit?  (Read 24832 times)

Offline sweetts

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Led exposure unit?
« on: November 21, 2012, 03:34:06 PM »
I saw on another site that people are building exposure units with Cree LEDs looking at the ranges it looks like you could get one In the wavelength needed. Anyone play with this here?
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Offline blue moon

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Re: Led exposure unit?
« Reply #1 on: November 21, 2012, 04:01:08 PM »
in the end you are really looking for a point light source. Having a lot of LED's would not be very different from black light fluorescent bulbs. . .

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Offline Screened Gear

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Re: Led exposure unit?
« Reply #2 on: November 21, 2012, 04:24:36 PM »
That's interesting. I think Pierre is correct about the point light source but I am sure you could build a point light source of sorts with a cluster of them in a shutter type fixture. I just can't imagine you would get faster than metal Hydride exposure times so the time spent messing with them would be a waist.
« Last Edit: November 21, 2012, 04:46:47 PM by Screened Gear »

Offline sweetts

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Led exposure unit?
« Reply #3 on: November 21, 2012, 04:34:01 PM »
I guess they have some that are equal to a 10k watter with 120+ degrees coverage so would more than one be needed? With it pulling 3 watts imagine the savings, no heat issues and they should last forever with minimal degradation, I am just thinking if this could be on the horizon for the industry. With variable wavelengths you could in affect dial in you wavelength to match your emulsion, then change the settings of voltage and boom you have a light table. 
« Last Edit: November 21, 2012, 04:38:35 PM by sweetts »
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Offline Binkspot

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Re: Led exposure unit?
« Reply #4 on: November 21, 2012, 04:38:53 PM »
They use UV LED's to cure UV inks so I would assume (hate assuming) they would work fine for exposing. Heat would be a non issue, and the life cycle would be huge. Again with an assumption but clusters could be set up as a single light source using reflectors to concentrate the UV energy to a single point.

Offline Rockers

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Re: Led exposure unit?
« Reply #5 on: November 21, 2012, 04:48:53 PM »
Such an exposure unit would be very expensive. Probably a lot more then any other unit out there.

Offline Itsa Little CrOoked

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Re: Led exposure unit?
« Reply #6 on: November 21, 2012, 07:29:44 PM »
The LED game is changing RAPIDLY and I'd just be VERY reluctant to say it isn't ever going to happen.  It maybe not quite ready for our application yet, but stay tuned.

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Offline sweetts

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Led exposure unit?
« Reply #7 on: November 22, 2012, 12:46:43 AM »
Wow thanks for sharing those are bright
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Offline RichardGreaves

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Re: LED exposure unit?
« Reply #8 on: November 22, 2012, 12:28:14 PM »
I saw on another site that people are building exposure units with Cree LEDs

looking at the ranges it looks like you could get one In the wavelength needed.

Anyone play with this here?

Please share where and what you found.

For year friends have shown & brought small UV LEDs for curing adhesive & thin deposits of ink.

Penetration through the large surface area & thickness of stencils & mesh is more difficult.

Cree does mention their blue and royal blue LED components (450-485 nm dominant wavelengths) but in the 30 minutes I spent prowling, I found no specifics so your sightings may help target some viable info for screen makers.

Don't get me wrong, I understand LEDs are the next HUGE thing when it arrives, but we still live in a DIY world where inefficient US$1 incandescent quartz halogen work lamps & low energy diffused fluorescent lamps are popular with textile printers.

I'm interested in testing lamps with strong UV-A OUTPUT.

Stronger means better penetration to cure the entire stencil.
« Last Edit: November 22, 2012, 12:31:16 PM by RichardGreaves »
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Offline sweetts

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Led exposure unit?
« Reply #9 on: November 22, 2012, 12:32:37 PM »
It was a post on t-shirt forum.com (hope it's ok to mention them here) a guy built one and is having good results after that post it put me on the road to researching the Cree LEDs and what they are capable of.
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Offline Frog

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Re: Led exposure unit?
« Reply #10 on: November 22, 2012, 01:34:25 PM »
I know that in the more enlightened states like California which have decriminalized medicinal marijuana, the grow supply shops have LED UV lights.
For those remaining to appear inconspicuous, the lower power use could be a real plus.
That rug really tied the room together, did it not?

Offline sweetts

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Led exposure unit?
« Reply #11 on: November 22, 2012, 02:03:25 PM »
Now all we need is good air filter to hide to smell lol
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Offline RichardGreaves

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Re: Led exposure unit?
« Reply #12 on: November 22, 2012, 02:39:46 PM »
It was a post on t-shirt forum.com (hope it's ok to mention them here)

a guy built one and is having good results after that post it put me on the road to researching the Cree LEDs and what they are capable of. 


http://www.t-shirtforums.com/screen-printing-equipment/t189229-2.html#post1197853
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Offline Frog

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Re: Led exposure unit?
« Reply #13 on: November 22, 2012, 03:20:23 PM »
Yep, but unfortunately, one has to sign in (and if also necessary, sign up) to see images there.
That rug really tied the room together, did it not?

Offline ScreenFoo

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Re: Led exposure unit?
« Reply #14 on: November 26, 2012, 02:23:27 PM »
IMHO, using the larger higher power LED's with higher divergence would not show the strengths of the technology--as mentioned, it would turn into a Fluo UV type unit.


I spent more than a few hours looking into this, and I believe it will be quite promising--in the future.  There are suppliers who deliver 370 nM (as well as 350 nM and 400 nM) 5V 20 mA LED's that are extremely efficient, and I've seen packages that keep the angle down to seven degrees.  Seems to me that would be 'collimated' (My bad SP or the dictionary?  :o ) so the real question would be how many you need for a full size grid--As the cheapest of the cheap still come in right around a buck each, and the answer I came up with was "too many".