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screen printing => Screen Making => Topic started by: Doug S on August 21, 2013, 12:26:12 PM
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I've been little busy lately so I haven't had much time to experiment much until this morning. I'm attaching the test I've done this morning with the chromaline blue. Also I ran an extra positive of black percentages from 90% down to 3% but the 3% isn't happening. I've also exposed a 230 with the time in the attachment and was able to hold down to the 7% at 56 lpi. I may have held down to 5% with a 305 but I will have to find time to test that. I know Alan is going test the Vastex with dual cure and will probably beat me to it but I'm going to expose the CCI WR-25 probably next week.
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I've been little busy lately so I haven't had much time to experiment much until this morning. I'm attaching the test I've done this morning with the chromaline blue. Also I ran an extra positive of black percentages from 90% down to 3% but the 3% isn't happening. I've also exposed a 230 with the time in the attachment and was able to hold down to the 7% at 56 lpi. I may have held down to 5% with a 305 but I will have to find time to test that. I know Alan is going test the Vastex with dual cure and will probably beat me to it but I'm going to expose the CCI WR-25 probably next week.
is this a dual cure emulsion?
pierre
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If I'm not mistaken, I believe Alan was only testing the HVP, right, and not a diazo/dual cure (I don't think he adds the diazo to his HVP)? I guess we'll find out. Those Chromablue #'s are virtually the same time that I'm getting already on our 40-1ks unit. Hopefully, the LED unit will blow the WR-25 out the water though with great times. I think we were at something ridiculous, like 7-9 minutes (can't recall exactly) and it still was breaking down on press with the WR-25 + hardener, so it must've been underexposed still.
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I've been little busy lately so I haven't had much time to experiment much until this morning. I'm attaching the test I've done this morning with the chromaline blue. Also I ran an extra positive of black percentages from 90% down to 3% but the 3% isn't happening. I've also exposed a 230 with the time in the attachment and was able to hold down to the 7% at 56 lpi. I may have held down to 5% with a 305 but I will have to find time to test that. I know Alan is going test the Vastex with dual cure and will probably beat me to it but I'm going to expose the CCI WR-25 probably next week.
is this a dual cure emulsion?
pierre
No it's photopolymer. By the way, I forgot to mention that I was using the ulano step wedge test and although I can't see as well as I use to those times are fairly close. I could probably tweak a couple of seconds on either side of those exposures and maybe get a little better results. Also, I was coating with the sharp edge of the coater. I'm anxious to see how the wr-25 exposes but I'll have to wait until I have more screens ready. I've been using the heck out of them lately.
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Here you go
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If I'm not mistaken, I believe Alan was only testing the HVP, right, and not a diazo/dual cure (I don't think he adds the diazo to his HVP)? I guess we'll find out. Those Chromablue #'s are virtually the same time that I'm getting already on our 40-1ks unit. Hopefully, the LED unit will blow the WR-25 out the water though with great times. I think we were at something ridiculous, like 7-9 minutes (can't recall exactly) and it still was breaking down on press with the WR-25 + hardener, so it must've been underexposed still.
The chromaline actually exposed slower with the nuarc 3140 I had than the Aquasol HV by about 20%. I just have a couple of gallons that I'm using so they won't go to waste. The main thing I like about the led is that it doesn't get hot so I can keep my films without losing all of the ink to the back of the screen due to sticking. That would always happen about 8 to 10 screens into exposing with the nuarc so I know it was due to the glass getting hot.
I'll post those numbers on the wr 25 as soon as possible. I may only have time to expose a 156 for an exposure test but I will get it done.
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Ok here we go. I used CCI WR25 and coated 2/1 but will probably have to go to 2/2 for plastisol. The attached are the exposure times I've come up with so far. The 230 held 5% halftones and the 150/48 held 10%. I doubled the recommended times from the tech sheet on the Chromaline site for a 5000 watt halide and the exposure didn't come out to half so it's not comparable to a 5000 watt halide but imho it's a darn site faster than the 6 to 8 minutes I would have to expose on my 1000 watt nuarc 3140 for water resistant emulsions. Of course I don't have anything to test at the moment for durability, but I can tell you that it's almost impossible to get the emulsion to blow out from the squeegee side with a pressure washer after the exposure.
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Wow. This may be off-topic, but I still say a converted Nuarc flip top is the best bargain going. My 3000 watt unit with a 8 year old bulb does a 2/3 156 dual-cure in 37 seconds, and used 6000 watt units regularly go for ~$1250 and often much less.
Since my flip top only fits smaller screens I have a wall mount vacuum frame with an Olec 8000 watt Trilite. And the Fliptop is over twice as fast. Had I known before I just would have bought a used, bigger, 6000 watt fliptop which fit 23 x 31 and bigger with no problem. I bet it would do the same 156 dual cure in under 30 seconds.
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Here's the problem, I bought a 7500w Amergraph. It's a sweet unit. exposures are under 30 seconds, fits 2 auto frames, fast draw blanket.
I paid $1600 for it, plus $900 for wire, conduit and a junction box to wire it in. This thing sucks 55A, that's some serious power. If you are cutting a lot of screens, LED is the way to go, but you would need more than 1. The power savings alone would easily offset the cost of a huge unit like the Amergraph.
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Also, it's not fair to compare the cost of a new LED unit with an older, used MH which are much more plentiful and will remain so for some time.
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well, yes and no, you do have to look at what the market has, and LED does have to compete with used MH units. if the price of used gets dirt cheap, it's devalues new units....and vice-versa
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well, yes and no, you do have to look at what the market has, and LED does have to compete with used MH units. if the price of used gets dirt cheap, it's devalues new units....and vice-versa
But I see it a bit like (more than) a few years back when folks may have been comparing new MH units with used carbon arcs.
Of course, often, cost and savings is the bottom line.
I remember once choosing between having a great deal on a car that got relatively poor mileage, and a more expensive one with better milage. When figuring out actual use and actual gas consumption cost, it was still determined to be the better deal over a few year period.
Good handling as well ( '74 Skylark I think)
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Hi,
I am a newbie here. And I would like to buy a LED exposure.
After reading many posts, I can't figure out what difference among Vatex E-2000, M&R starlight, Lawson LED-5000.
Exposure time, vacuum time, screen exposure quality.
If I can't figure out the difference, maybe the price is the reason to buy one.
For exposure time, starlight and E-2000 are short, E-5000 is longer after I read some posts.
For vacuum time, no big difference.
For quality, I don't find related post.
I am not in America, hope to get some advices, thank you very much!
Earl
ps. There are other LED exposure like baby joe and lightspeed, too.
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Different emulsion different time. Please check cci hxt.
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Hi,
I am a newbie here. And I would like to buy a LED exposure.
After reading many posts, I can't figure out what difference among Vatex E-2000, M&R starlight, Lawson LED-5000.
Exposure time, vacuum time, screen exposure quality.
If I can't figure out the difference, maybe the price is the reason to buy one.
For exposure time, starlight and E-2000 are short, E-5000 is longer after I read some posts.
For vacuum time, no big difference.
For quality, I don't find related post.
I am not in America, hope to get some advices, thank you very much!
Earl
ps. There are other LED exposure like baby joe and lightspeed, too.
I believe Vastex bought the Baby Joe design.