Brown led exposure system

[Steve Harpold]

Hey All,

While I was discussing the Fire Fly system i saw a lot of comments regarding LED exposure systems. Below is the stats on the Brown LED system released nearly 3 months ago.

Standard Led unit:
Size: 1 - 23x31
Photopolymer: 15-25 seconds
Dual cure - 1:30 - 2:00 mins

Also available 2- 23x31

LED X Series
Size: 1 - 23x31 or 2- 23x31 or size 48" - 48" and 48" x 72"
Photopolymer- 3-12 seconds
Dual cure - 30 - 1:10

The Brown led exposure were designed using a light modeling software to eliminate/reduce undercutting. The led light sources are 4" away from the glass (will solve the issues of heat on the glass the others have experienced) The system is built on a 4" x 4" grid allowing for it to deliver a even light across any size frame.

This system will also be at ISS Atlantic city show

Again thanks and I look forward to demonstrating The Fire Fly, Dragon Air and Led exposure system at the Show.

[TCT]

You got any pics you can post for those of us not hitting the east coast next week?

[Steve Harpold]

Pictures and details can be found here: http://brownmfg.net/p/372/led-exposure-system

The LED system also has:
10 programmable pre-sets
Delay vacuum draw down
And Amber safety lines on a separate channel.

Brown mfg is achieving some of the fatest exposure times in the industry with only 42 leds total, to expose a 23x31 screen.

What this does:
Reduces the number of failure points by nearly half competitors
Speed: fatest times reported
Heat: removes the issue of heat at the glass
Undercutting: similar to old style black light or flourescent bulbs putting them directly next to the surface and not specifying the angle of light ( buying bulbs of the shelf and placing them in a exposure box) will result in the same performance issues commonly referred to before.

 We have procurred custom proprietary LED's which are ordered at a specific angle and wave length. It allows us to put the LED's 4" from the surface and maintain the angle of light desired, eliminating undercutting issues. The custom power and wave length maintains speeds from that distance away.

Thanks for the interest 

[jvanick]

Can you comment on the wavelength of the leds?  Are they multi-spectral?

[Steve Harpold]

I guess the best answer is no I cannot elaborate on that as these items are proprietary to Brown Mfg
I can only prove thought testing and trials.

Thanks for the interest

[Steve Harpold]

Stop by the Atlantic city show and I can better answer all questions.
I also sent a machine to SPSI for their open house March 17-19

The race is on, I can confidently quote all emulsion types under 1:00 minute!!

[TCT]

What's list price?

[Steve Harpold]

Lowest cost unit handles one 20x24 screen
Image area: 16x24 
Photopolymers- 25 seconds
Dual cure -  1:30 - 2:15
2,495

Low power unit
Image area: 23x31
photopolymers - 25 seconds
Dual cure - 1:30 - 2:15
4,295


High power
Image area: 23x31
Photopolymer - 5-12 seconds
Dual cure 35 -1:15
5,995

Recommended unit
Image area: 23x31
Photopolymers: 2-12 seconds

[sben763]

Here go again. Eliminates the under cutting.  Please post some data  to support the claims.  They are using blue LEDs. The spectrum will be in the higher end of the spectrum. They are also cheaper then the violet LEDs not that matters as long as they work. My guess is they are using 15 degree beams at 4" but maybe 30 degrees. Didn't want to do the calculation.   If they are 3w at 42 it would be 126watts and 5 watts 210 watt total. 

I have a DIY unit that I am willing to put against any of these commercial units. I know though everyone isn't willing to do a DIY.  Right now it's only 100w soon to be 200w.  Maybe I should talk to one of these manufactures. I haven't seen I manufacture with my design. I've tried the way the manufactures are doing LED and the results are definitely different. Although I don't have a densitometer I have compared at 500x magnifaction screen to exposed film and have done several other comparisons with other manufactures units. 

Willing to expose a screen for me with either supplied screens and film or supply a exposed screen and film, I'll pay for the materials and shipping.  If it's everything you say I'll support the claims.

[balloonguy]

Here go again. Eliminates the under cutting.  Please post some data  to support the claims.  They are using blue LEDs. The spectrum will be in the higher end of the spectrum. They are also cheaper then the violet LEDs not that matters as long as they work. My guess is they are using 15 degree beams at 4" but maybe 30 degrees. Didn't want to do the calculation.   If they are 3w at 42 it would be 126watts and 5 watts 210 watt total. 

I have a DIY unit that I am willing to put against any of these commercial units. I know though everyone isn't willing to do a DIY.  Right now it's only 100w soon to be 200w.  Maybe I should talk to one of these manufactures. I haven't seen I manufacture with my design. I've tried the way the manufactures are doing LED and the results are definitely different. Although I don't have a densitometer I have compared at 500x magnifaction screen to exposed film and have done several other comparisons with other manufactures units. 

Willing to expose a screen for me with either supplied screens and film or supply a exposed screen and film, I'll pay for the materials and shipping.  If it's everything you say I'll support the claims.

Would you share some pics/specs. I would to try a DIY project like this!

[Steve Harpold]

Hey,

I am sure by your quick response that you like me live and breathe this stuff (Probably a little to much)
Below is a quick explanation or our exposure unit, let me know what you think, thanks

1. Angle
       A. We have selected and specified a specific angle. Yes you could calculate this angle with the proper information. We used a light modeling software to come to our conclusion. We chose a distance of 4" from the glass. Consider a cone shape, place it to close and the light in the center is more intense than the outer light. Place it to far away and the outside light will tapper off our cross paths with another source. With a proper angle and distance we can prevent undercutting. (Similar to the thoughts behind a single point source *For science majors, I know single points don't truly exist but for sake of demonstration) I am not sure how competitors are handling this from .25" away from the glass?

2. Proper Wave Length
      A. Ignore photo polymers as we had to tapper the power supply back to publish reasonable results. 1-5 seconds is to fast.
      B. Testing 15 different diazo/dual cure emulsions selected a wave length that would respond to all

3. LED Testing
       A. Though we purchase a LED built for Brown MFG, we test all LEDS Coming in the door for the selected wave length
       B.  Rejecting nearly 30% of all entrants

4. Power supply
       A. 700 MA, we could drive the LEDS harder as they would respond and perform better. However it is important to guarantee life span than push the LEDS beyond specs.

These are the specs I am willing to share,
As Brown Mfg continues to push the limitations, there is no doubt in my mind that there are other minds pushing the same. Some days DIY guys are just flat better at it. (I am/was/and will always be on of these guys striving to push the limitations)

So....Let see whose science is better,
                    A. Select a trade show close to your location
                    B. I will provide booth space, power. You bring you DIY unit, I will bring my LEDX 2331 unit, the specs are listed above
                    C. I am sure we can find 3 members of this board to judge the challenge
                    D. Dual Cure Emulsion (Your choice) let me know ahead of time
                    E. Coated 1  x 1 with the round edge
                    F.  Artwork 75lpi

10. If you win i will give you the LEDX2331 unit. (which of course will need work as your was faster)
11. If I win you purchase the the demo unit at (5,995 less 1,500 = $4,495)

I am always willing to stand behind my products even it means I have to admit someone else can do it better!

[sben763]

I would agree to most of that. A few things I am not. 1 dual cure that maybe negotiable though. It's been 6 or 7 years since I've touched the stuff. Judge. What judges. It would have to be based on the actual results. That can be compared by a scoring system. Dots lost, dot size compared to the film,   Why stop at 75 LPI. This was 85 LPI on a 272.  Although a very simple graphic and not a great one for fine detail, I am going to redo a film and screen, line them up and take some photos from the microscope.

I am sure you products are just fine. Maybe I came off wrong but every manufacture claims this undercutting fixed while I just don't see it.  You have a multi source light and it's going to be there in some fashion, I did gain some respect though cause your statements about the single point.  That's all you ever hear about but yet with reflectors installed as there is in all exposure units which causes your light to bounce.   Although single source light is still the sharpest no matter what type of light. 

I'd be willing to take the challenge but there would be some changes to the challenge.  Heck I might have to go get some dual cure to test since suppose to be better for detail work I have always just stuck with the photopolymer since since switching. 

[TCT]

Do you guys make a unit for 25*36 frames?

What's list on it?

What exposure times are you guys seeing with Murakami SP-1400?

How are you determining your screens are exposed/crosslinked/cooked fully? For me this is huge, if you are just printing plastisol you can underexpose tremendously and a screen will still work. Waterbase or HSA inks reek havoc on underexposed screens.

[Steve Harpold]

Hey,

A photopolymer is a very fast exposure and will expose with several wave lengths. Many of which are commercially available. Dual cure emulsions are not as sensitive to such a large band of wave lengths. They preform the best when exposed to a wave length shift the NM up by 10 and they will no longer perform at all!!!! Many of the led EXPO units have a disclaimers, they will expose a photopolymer in 30 seconds or less. And for some emulsions it could be 1-5 minutes or higher.  These exposure units are using commercially available sources. Simply upping the wattage without the correct wave length will not help.

Under Cutting:
The use of reflectors is counter productive to this concept.  The goal is to get the cleanest light and not bounce light all over a enclosed box.  However in the chase for speed many have chosen to bounce the light of reflectors as to not waste any energy. We used s light modeling software placing a led in a pattern taking into account the angle and cone that the LED produces the each beam of light covers a 4" x 4 " area. Of course there is always a small overlap, with the modeling software we are able to ensure that where that small overlap occurs the intensity of light is +/- 10%.  I will post the graph on what it looks like once the light is measured.

Side note: The wattage of our system to expose a dual cure that fast is: 560 watts (in this case you have worry about proper heat sinks. Try a diazo, let me know how fast you can expose it and how clean.

Also send me a message with your info and I will send you a screen back exposed.  Please mail the art with the below picture to:
Brown Manufacturing
Attn : Steve
4661 Stafford
Grand Rapids, MI
49548

Thanks

[blue moon]

Hey,

A photopolymer is a very fast exposure and will expose with several wave lengths. Many of which are commercially available. Dual cure emulsions are not as sensitive to such a large band of wave lengths. They preform the best when exposed to a wave length shift the NM up by 10 and they will no longer perform at all!!!! Many of the led EXPO units have a disclaimers, they will expose a photopolymer in 30 seconds or less. And for some emulsions it could be 1-5 minutes or higher.  These exposure units are using commercially available sources. Simply upping the wattage without the correct wave length will not help.

Under Cutting:
The use of reflectors is counter productive to this concept.  The goal is to get the cleanest light and not bounce light all over a enclosed box.  However in the chase for speed many have chosen to bounce the light of reflectors as to not waste any energy. We used s light modeling software placing a led in a pattern taking into account the angle and cone that the LED produces the each beam of light covers a 4" x 4 " area. Of course there is always a small overlap, with the modeling software we are able to ensure that where that small overlap occurs the intensity of light is +/- 10%.  I will post the graph on what it looks like once the light is measured.

Side note: The wattage of our system to expose a dual cure that fast is: 560 watts (in this case you have worry about proper heat sinks. Try a diazo, let me know how fast you can expose it and how clean.

Also send me a message with your info and I will send you a screen back exposed.  Please mail the art with the below picture to:
Brown Manufacturing
Attn : Steve
4661 Stafford
Grand Rapids, MI
49548

Thanks

Steve,

of the two commercially available units I tested (with spectrometers), light field was at 5% and 1% fluctuation. If you are saying that you have a 10% variance in the strength of your light field on the glass, that is too much. Did I misunderstand something?

pierre