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screen printing => Screen Making => Topic started by: mimosatexas on December 11, 2016, 02:10:34 PM
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low on emulsion and working over the weekend. Have a quart sample of the CP Tex I just sensitized. Wondering if anyone has any idea how exposure time would compare to the SP1400 (more? less? same?). Going to do a stouffer strip test, but would love to not "waste" too many screens trying to nail down exposure if someone can give me a general idea. Thanks!
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We used it last a couple of years ago, and from what I remember the exposure times are faster then the ones of the 1400.
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looking at their tech sheet suggested exposure times, the only identical examples that could be used for comparison would be
110 white with a 5k MH
CP tex - 60-90 sec
SP1400 - 120-150 sec
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So after testing, same exposure time for both gets me a hard 7 on the SP1400 but only a hard 6 on the CP Tex and a "soft" 7. Increasing the exposure time around 25% gets me the hard 7 on the CP Tex, so it is actually taking longer to expose. No clue why...
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hit up alex, TCT, as he swears by sp1400
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screw all that, go with Chroma line Chroma tech wr, fast exposing, give it a post expose, no need for diazo, no need for hardener. I get 1 second exposures on the starlight on 305-280, 2 seconds on 230 or 225 s mesh, 150 s, 3 seconds. Post exposures are a minute "over doing it" on the starlight. ZERO break down issues. Awesome halftone emulsion for sim process jobs, it's the bomb!!!
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hit up alex, TCT, as he swears by sp1400
SP1400 has been my go to daily emulsion for probably a year and a half or more. I love it, but ran out and had to make do with whatever I had on hand in a pinch: the CP Tex. After testing, I definitely will be sticking with the SP1400.
Was mainly curious why it was taking longer to expose vs shorter since it seems like it "should" take less time.
A bit more about my side by side comparison:
-the SP1400 is harder to wash out than the CP Tex when both are exposed to a hard 7. the CP Tex basically falls off the screen coming out of the post expose tank vs the SP1400 which is just softened up.
-the CP Tex seems to stain a bit from waterbased inks. With the SP1400 I can pressure wash the ink off completely, no need to scrub AT ALL and all that's left is emulsion. The CP Tex required a little scrubbing, and even that wouldnt remove a bit of the pigment. This is not in the image area, but rather on the surface of the emulsion around the stencil. It isn't a huge deal for me, but is a difference and if you didnt reclaim screens quickly might lead to haze?
-CP Tex is a bit stickier when it comes to the film. Required a little baby powder to keep from pulling ink off the film.
-CP Tex costs more (SP1400 is dirt cheap)
-CP Tex has an ugly brown/purple color vs the pretty green (this doesn't actually matter obviously :D)
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screw all that, go with Chroma line Chroma tech wr, fast exposing, give it a post expose, no need for diazo, no need for hardener. I get 1 second exposures on the starlight on 305-280, 2 seconds on 230 or 225 s mesh, 150 s, 3 seconds. Post exposures are a minute "over doing it" on the starlight. ZERO break down issues. Awesome halftone emulsion for sim process jobs, it's the bomb!!!
not interested in post exposure. Just adds a step and a variable that I don't want to deal with. The SP1400 is pretty close to fast enough for my screen cycle right now with the 5k MH. When I used HVP I post exposed and hardened and blah blah blah. No thanks!
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Sounds like the CP has lower solids content than the SP which will cause the easier wash out as there's not as many links in it.
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What on earth is the benefit of a 1 second exposure if you have to come back, after it dries, and hit it again for another minute?
Sounds like a 61 second exposure to me, plus an additional loop in the process.
Been on the 1400 for 4-5 years now and you can pry it from my cold dead hands.
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Sounds like the CP has lower solids content than the SP which will cause the easier wash out as there's not as many links in it.
I believe they are both 42%.
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screw all that, go with Chroma line Chroma tech wr, fast exposing, give it a post expose, no need for diazo, no need for hardener. I get 1 second exposures on the starlight on 305-280, 2 seconds on 230 or 225 s mesh, 150 s, 3 seconds. Post exposures are a minute "over doing it" on the starlight. ZERO break down issues. Awesome halftone emulsion for sim process jobs, it's the bomb!!!
not interested in post exposure. Just adds a step and a variable that I don't want to deal with. The SP1400 is pretty close to fast enough for my screen cycle right now with the 5k MH. When I used HVP I post exposed and hardened and blah blah blah. No thanks!
The post expose time is still less time than it takes to expose the cp tex or sp 1400, Ive been there too, but what ever someone is comfortable. No hardener or diazo needed in the chromatech wr. One emulsion for everything with that one. 5k lamp will expose it in probably under 30 seconds, even if you aren't CTS. It's really nice stuff.