CCI White still eating emulsion

[mimosatexas]

So I have tried all sorts of stuff with my Aquasol HVP and nothing is helping it stand up to the CCI discharge white for longer than a few dozen prints.  I bought SP1400 locally to try instead, added diazo, and began testing.  So far it is also failing pretty miserably, though the detail it holds compared to the AqHVP is surprisingly good.  I am holding literally every single dot my printer outputs at 55lpi.

Here is what I have tested so far:

Exposing 225S and 160 mesh, coated 2/1 for 4:45 and 5:20 respectively, based on a stouffer step test to hard 7 soft 8 for each mesh count.  Both are yellow mesh.

I have tried no post exposure, 10 minute post exposure, 10 minute post exposure with MS hardener.  I have also tried, quick air dry by fan and overnight dry in the dry box, both post exposure.  All screens are dried overnight after coating.

No matter what, the CCI is making the emulsion tacky, then breaking down, then when washing out almost every dot under 5% is simply going away.  Clearly the emulsion is breaking down.  I have done 30-50 strokes on each test.

I have done similar tests with Matsui and Magna discharge whites and even just exposed, air dried, and put on press the SP1400 is holding up perfectly fine for 50 prints with those.

Any ideas?  I will likely be getting one of the CCI discharge emulsions next, but I really don't understand why it is so much more caustic than the matsui and magna that I have one hand.

[ericheartsu]

So I have tried all sorts of stuff with my Aquasol HVP and nothing is helping it stand up to the CCI discharge white for longer than a few dozen prints.  I bought SP1400 locally to try instead, added diazo, and began testing.  So far it is also failing pretty miserably, though the detail it holds compared to the AqHVP is surprisingly good.  I am holding literally every single dot my printer outputs at 55lpi.

Here is what I have tested so far:

Exposing 225S and 160 mesh, coated 2/1 for 4:45 and 5:20 respectively, based on a stouffer step test to hard 7 soft 8 for each mesh count.  Both are yellow mesh.

I have tried no post exposure, 10 minute post exposure, 10 minute post exposure with MS hardener.  I have also tried, quick air dry by fan and overnight dry in the dry box, both post exposure.  All screens are dried overnight after coating.

No matter what, the CCI is making the emulsion tacky, then breaking down, then when washing out almost every dot under 5% is simply going away.  Clearly the emulsion is breaking down.  I have done 30-50 strokes on each test.

I have done similar tests with Matsui and Magna discharge whites and even just exposed, air dried, and put on press the SP1400 is holding up perfectly fine for 50 prints with those.

Any ideas?  I will likely be getting one of the CCI discharge emulsions next, but I really don't understand why it is so much more caustic than the matsui and magna that I have one hand.

The reason we switched over to the NOVA emulsion is because it had ZERO problems like this. We use CCI White discharge more than any other ink in our shop, so for us it was worth the extra price to have no problems with screens.

sorry that doesn't help you now, but at least it's something to think about. I'm going to try some of the CCI emulsion this summer as well.

[Underbase37]

That does sound weird.....have you tried the CCI WR-14 others here have suggested this & we have had good results with it across several WB & DC inks runs 600pic. & up. With hardener longer runs like 1200, wash out & use again. Quick burn times for us too. If we rush it doesn't seem to last as long though. This is just us & I'm sure others have had different results.

Murphy37

[mimosatexas]

I long ago stopped caring about price for products that "just work".  I'll pick up some Nova asap.  Do you do anything special or just expose and go?  If I can cut out the post expose, overnight drying, hardener, etc. it would be awesome.  I just want to speed up turnaround on screens while using the CCI if possible.  It has such better dry in time and is so creamy out of the can vs the Matsui.  It is not quite as white/opaque, but those factors make it worth using to me.

I'll pick up some of the WR-14 as well.  Does it require any of the post expose, overnight drying, hardener, etc.?  Most of my runs are around 100-250 right now.  The AQHVP holds up fine at these quantities with post expose and hardener when using Matsui, but it fails on press in like 25 prints with the CCI.  The SP1400 is failing on press at around 25 with just expose and go, 30 with post-expose, and 50-55 with post-expose and hardener.  All are losing every dot under 5-10% on washout.  All of this is unacceptable.

[ericheartsu]

I long ago stopped caring about price for products that "just work".  I'll pick up some Nova asap.  Do you do anything special or just expose and go?  If I can cut out the post expose, overnight drying, hardener, etc. it would be awesome.  I just want to speed up turnaround on screens while using the CCI if possible.  It has such better dry in time and is so creamy out of the can vs the Matsui.  It is not quite as white/opaque, but those factors make it worth using to me.

I'll pick up some of the WR-14 as well.  Does it require any of the post expose, overnight drying, hardener, etc.?  Most of my runs are around 100-250 right now.  The AQHVP holds up fine at these quantities with post expose and hardener when using Matsui, but it fails on press in like 25 prints with the CCI.  The SP1400 is failing on press at around 25 with just expose and go, 30 with post-expose, and 50-55 with post-expose and hardener.  All are losing every dot under 5-10% on washout.  All of this is unacceptable.

This is what we do with the nova

1. open diazo
2. pure in WARM distilled water, about 1/4 of the container
3. shake diazo for about 5 mins
4. open up Nova Gallon
5. Mix in Diazon
6. Let sit for 2 hours
7. Coat screens 205 and under 1 pass on outside and inside, 230 and over, one pass on the substrate side, with the round edge of the scoop coater

*we might change step 7 to do it 1 pass on the outside and inside on all screens as we've been moving alot of our darker discharges to higher meshes.

No hardener. We post harden in the sun or in our exposure unit if we have a really big run.

We've been using the emulsion for about 2 years and have run into only one issue, when the temps. were changing alot we got a bad 5er from Xenon. that messed up some screens, but they were great about it. You can also tell the difference when coating right away.

Also we only had one screen breakdown, and that was earlier this week. For some reason the same ink/image broke down 3 different screens all coated the same way...so i'm looking into that this week.

[Underbase37]

We have run orders that size with no post-exposer or hardener but dry in the sun so if you don't have the sun you might want to post-expose. It seems like a good emulsion for lower wattage exposure units. But that's just us......also l have had good luck with being able to wipe the screen & things not being soft.

Murphy37

[Underbase37]

I still need to try the Nova & the few times I have talk to Sonny he is super helpful and a very friendly guy.

Murphy37

[ZooCity]

Nova could well be as close to bulletproof as it gets.  Hard telling for sure as we have 3 more to test before concluding.  Yes the cost is high and burn times are epic next to HVP but it sure is nice to be able to just wipe a DC screen with halftones on press after 100s or 1000s of DC/WB prints and not be scared shitless that the stencil is going to delaminate.  We add all the water to the diazo (too dry here to do the 1/4 or 1/2 water in the bottle, the emulsion will crack without enough water in there) and do pretty much like Eric.  Still narrowing down the coating thing but coating with it kinda throws out all the normal rules.  Doing coats from the substrate side only right now, considering drying ink side down for a better emulsion "sandwich" *another topic really.  It's not an emulsion for thicker stencils due to it's viscosity, flows too much after coating.  We still have to harden Nova but don't need to post expo it. 

You shouldn't be seeing these issues with the HVP. It's not as tough as some other emulsions but is good for many prints, it tends to just squeak by for most longer runs but hangs tough through most.  First thing I would look at is drying, the screens need to be uber dry before coating, after coating before shooting, after shooting.  Like bone dry.  If screens are in an environment where they could absorb ambient humidity before going to press, cook 'em again before going to print.

Do you have diazo in the HVP?  Are you coating that 225 with the thin edge of the coater?  What do you burn with?

I would def talk to Alan at Murakami as well, he's to Murakami what Richard Greaves was to Ulano in the past and has a very solid understanding of the emulsion all the way to a production level. 

[mimosatexas]

No diazo in the HVP.  Screens are as dry as I can make em at each step of the process (in a drying cabinet with dehumidifier and lots of airflow over night).  I am using the monster max coater, and both sides are rounder than the sharp side on most coaters, but sharper than the round side, if that makes sense.  I am burning with a 1k MH diy unit.

The part that is baffling to me is the difference between the CCI and the Matsui/Magna/Sericol/Jantex discharge inks and TW/Speedball/etc waterbased inks I've used without issue on the HVP (post exposed and hardened).  Nothing eats at it like the CCI...

The SP1400 with diazo only held up marginally better.

[Printficient]

Glad to help any who need it.  Nova is $82 per gallon.  404-895-1796

[blue moon]

No diazo in the HVP.  Screens are as dry as I can make em at each step of the process (in a drying cabinet with dehumidifier and lots of airflow over night).  I am using the monster max coater, and both sides are rounder than the sharp side on most coaters, but sharper than the round side, if that makes sense.  I am burning with a 1k MH diy unit.

The part that is baffling to me is the difference between the CCI and the Matsui/Magna/Sericol/Jantex discharge inks and TW/Speedball/etc waterbased inks I've used without issue on the HVP (post exposed and hardened).  Nothing eats at it like the CCI...

The SP1400 with diazo only held up marginally better.

it sounds like you are not properly exposing. After you burn the screen leave it out in the sun for a while and test again. It should be nice and sunny just to make sure you are getting enough UV. If the results are the same it's the exposure. . .

pierre

[Orion]

Murakami recommends adding the diazo and using either one of their hardeners for discharge/waterbase. When coating screens for dc/wb we use a thin 1 over 1 coat of emulsion, sharp edge of the coating trough. Try a thinner stencil, you may have a lot of moisture content in the emulsion, even with an environmentally controlled drying area, with your stencil thickness. HVP is 42% solids, it can make a thick stencil.  With the long exposure times you posted I would be concerned with what type of light source you are using. HVP is a pure photopolymer so it will benefit from post exposure, but if the initial exposure is insufficient then you will losing emulsion on the squeegee side of the screen during washout, which could lead to delamination.

[ebscreen]

What's your ambient humidity like? I'm guessing you're in Texas somewheres, and that ranges from bone dry to bayou.
Completely dry emulsion, both pre and post exposure is extremely important.

What kind of exposure unit? With SP1400 we're at roughly those times, and maybe longer (LU's, but they are roughly 1 second)
on a 3140 and a Photosharp. (1200 watt MH)

When we used to use Aquasol HV we'd post expose, wipe on hardener on long runs, and use the same screens several days in a
row on super long discharge runs. Never gave us any issues.

[CCI TECH]

Try WR-14 or TX-Discharge for short to medium run discharge ink jobs. Try our C-Tex for long run waterbase / discharge runs for bullet proof stencils. When used with our PermX hardener we have had customers print 150,000 imprints of white discharge ink. We also make a reclaimable hardener called HardenX. The key to hardeners is to let them sit after you wipe it on. Over night dramatically increases the resistance, than just wiping it on and going to press. The hardeners need time to crosslink and it takes hours to do this. Try that next time you make a waterbased screen. Put the hardener on the night before.

Let me know if you have any questions.

[alan802]

Try WR-14 or TX-Discharge for short to medium run discharge ink jobs. Try our C-Tex for long run waterbase / discharge runs for bullet proof stencils. When used with our PermX hardener we have had customers print 150,000 imprints of white discharge ink. We also make a reclaimable hardener called HardenX. The key to hardeners is to let them sit after you wipe it on. Over night dramatically increases the resistance, than just wiping it on and going to press. The hardeners need time to crosslink and it takes hours to do this. Try that next time you make a waterbased screen. Put the hardener on the night before.

Let me know if you have any questions.

We've never waited long after applying hardener before going to press and we've had mixed results so this will probably help us tremendously.  There have been times where we've been on press within 5 minutes of applying hardener and only on a few occasions do I remember having the screen ready a full day before the run.  It makes perfect sense but I never really put much thought into it needing time for crosslinking.  With that said we have tried out a few DC/WB emulsions but have settled on HVP due to it working well with plastisol and others' having success with long DC runs without diazo.  We've done a few runs of 1-2K with the stencils holding up and post exposed along with hardener, no diazo.  I'd love to have an emulsion that we could use for all our plastisol as well as DC jobs and it not need all the extra work prepping the screen but the HVP has done well for us after we figured out the exposure issues.  We were underexposing and couldn't really figure it out since all the physical signs of underexposure were not there at all, they seemed like they were bordering on overexposure if anything.  After learning the exposure times needed the HVP with hardener holds up to whatever we throw at it.