"He who marches out of step hears another drum." ~ Ken Kesey
Ok, so I just got off the phone with 2 Saati guys....Danny, is yours more of a circular unit vs. rectangular? They were thinking you may have the "100" unit, which is more of a circle and they said has been used for post exposing with CTS units.The "300" unit @ 44" from the glass they said was equivalent to a OLIX(sp?) 3000 watt unit. Exposure times vary depending on placement from the glass, mesh, emulsion, yada, yada, yada... But they said a safe or common range they were seeing was 17-27 seconds.The 300 unit is made up of 3 actual lights focused, the 100 is 1 light and they are working on a 500 unit but are having hurdles keeping it cool enough. They were actually in the airport on their way to a company that makes exposure units to work out a deal. Sounds like they would IDEALLY down the line like to have a whole unit with vacuum blanket timer and all for under $3K in the future. They are getting me a handful of contact info for current US users that I can talk to and see what they think....
OK, light energy in the correct wavelengths is what exposes emulsion. How many watts? At what distance? 300w compared to a 5,000 watt Metal Halide? Proximity to the screen is what helps the Starlight and other LED's to expose emulsion, and most have limited multi spectral capability that dual cures love. I'd love to hear tests. Here is the acid test: Coat a 110 1:2 with your emulsion. Expose it for the same time at the same distance as you are using now. I doubt the emulsion will stay on the screen without a far longer exposure using a 300w LED than the 1k and 5k units. Even the difference between an Olec 8k and 5k is quite a lot as far as emulsion durability. Weak light = weak screens. Maybe Ok for plastisol and small runs, but a long discharge run, or worse a long High Solids Acrylic ink run? no way. LED's conjure up all sorts of savings in electricity and lamps, but image quality and reject rates, especially on discharge could be painful. We have experimented with a variety of LED's from a major LED manufacturer. We have tested some so strong they burnt holes in the mesh due to being so close. The best times we came up with in a scanning LED had times equal to the 5k metal halide in the lab, but did not pass a simple ink test with Matsui 301 whereas a multi spectral MH 5k bulb exposure showed no breakdown of the emulsion. We have seen good results with the Starlight in our tests and it is due to how close the lights are to the screen. You will see emulsion manufacturers coming out with LED emulsions. Trouble is they need to be tuned to the wavelength of the sensitizer. Diazo likes 360 nanometers, SBQ likes 380, 420. So if the lamp has only a single spike wavelength in the histogram it may not fully expose a dual cure. It may appear to be fully exposed, even without slime on the inside, but the cross linking going on in the emulsion will be partial and not as complete as a 5k-8k fresh Metal Halide. Call the emulsion what you will, diazo is the magic ingredient that helps with water resistance and it likes 360nm so how will a 405nm light expose that completely?LED is in it's infancy. It's only going to get better. Anyone with results on any LED lamps using Discharge would be appreciated. If the screen can hold up to a long discharge run and hold good tonals then the LED light has benefits. Printers make money when the presses run, if the light source doesn't shoot durable screens the profits suffer. Short runs, probably won't matter, for the long runs? I have seen disasters and major headaches at shops running longer discharge and HSA ink print runs suffering screen failure and with plastisol showing major pinhole issues. Al
Had a demo of the single unit last week and for the money looks like great results in our CTS shop.I think we will be going forward with the triple soon, although the concept of no integrator is a bit counter to my upbringing.Sent from my iPhone using Tapatalk
contrary to popular belief, LED's do deteriorate with time, but significantly slower than the MH bulbs. It is possible that there would be no difference after a year, but I would imagine 5 years would be a different story. This is just a guess on my end based on what I've heard.also, heat is significant factor in the life and output of the LEDs. So there will be variations from shop to shop.pierre
I was surprised at this-mk162-here's the thing...LED's are only about 11% efficient.Why so much waste?
Quote from: blue moon on November 13, 2014, 12:12:15 PMcontrary to popular belief, LED's do deteriorate with time, but significantly slower than the MH bulbs. It is possible that there would be no difference after a year, but I would imagine 5 years would be a different story. This is just a guess on my end based on what I've heard.also, heat is significant factor in the life and output of the LEDs. So there will be variations from shop to shop.pierreThis was my thinking on deterioration. So a unit like the Starlight contains no integrator? I guess I should've asked! That seems like a no-no to me. I'm not nearly as old as some of you ancients on here talking about stat cameras but I'm in the camp, it really goes against my basic understanding of exposure to not have an integrator. I suppose one could be added and wired into the controls....seems like that should be included with the units for the price. Clearly nobody has done a 5yr test on any of these yet.
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Topic: Single point LED.... (Read 15298 times)
