Help me understand why my emulsion is locking up

[ericheartsu]

Emulsion: Xenon Nova (dual cure, with diazo)
Chemistry: CCI HR-30 for plastisol, CCI eco wash for waterbased/discharge inks
Dip Tank: Easiway Easi-strip (in the past we used cci genzyme)

We keep getting locked up screens when we are reclaiming them, and we cannot figure out why!

Our screens are kept around 30ns, we are using shur loc and new man panels. Plastisol is never left on screens longer than a day, and waterbased is washed out immediately.

 We have light staining on our mesh, but it's taking about 20 mins to spray out a screen, even after soaking in a dip tank for 5 mins.

I've talked to Sonny about this for a long time. He suggested our dip tank chemicals got trashed, so we tossed our CCI genzyme, and switched to Easi Strip. it helped, but only for a week. now we are back at the same problem.

CCI suggested that it could be the HR-30 that we use to reclaim our plastisol screens, which it might be. I believe it's a solvent based cleaner, and it's possible this emulsion is not solvent resistant.

I have my guy trying some screens with citra paste as I type this! so hopefully that's the cure all, but this is our second wind of a busy season, and we are washing out about 30 screens a day. So any suggestions would be awesome!

[Frog]

In the old days, we actually hardened some emulsions by wiping with our cleaner, Xylene.

Underexposed screens are even more susceptible to this effect.

[starchild]

I would also take a look at my emulsion curing area and recheck my exposures..
Heat is what locks emulsion, mainly the ones that did not properly crosslink..

[jsheridan]

this sounds like under exposure and or you are using the stain remover before reclaim.

check for proper exposure
reclaim the screen first, then use the stain remover and final degrease step at the end.

[ericheartsu]

i'm going to check our exposure this weekend, but we had it pretty dialed in with the i-image. at least i thought we did.

And typically we'll clean off all the ink, put in the dip tank, spray with liquid renuit, then degrease if needed

[Homer]

reading the description of the CCI HR-30, it says it can be used as a haze remover. I would toss a bet that this is the culprit and it may be killing your tank fluid.

[Binkspot]

Aerosols like screen opener or mineral spirits used on press to clean an image area will harden emulsion making it difficult to remove in reclaim. Take note how the emulsion comes out of the screen, areas that have been cleaned with one of these products will come out in stringy sheets, the unaffected area should just wash out.

Killing the tank is one reason we go straight from press to the dip tank, adding another chemical to the tank could kill it. If you do want to remove the ink before hand make sure the remover is compatible.

[Frog]

i'm going to check our exposure this weekend, but we had it pretty dialed in with the i-image. at least i thought we did.

And typically we'll clean off all the ink, put in the dip tank, spray with liquid renuit, then degrease if needed

Liquid Renuit functions as a degreaser (though expensive if used for only that, LOL!)

All symptoms seem to lead back to a possible combination of a solvent ink cleaner and underexposure, and possibly the emulsion itself, as when I used Nova one part, it reclaimed more like bubble gum than actually dissolving.

[mimosatexas]

have you tested exposing a screen and putting it directly in the tank? no ink or cleaning before dipping.  That would narrow down the issue.  You could also clean little areas with different chems on a single screen and see if any areas are harder to remove post dip.

[Printficient]

have you tested exposing a screen and putting it directly in the tank? no ink or cleaning before dipping.  That would narrow down the issue.  You could also clean little areas with different chems on a single screen and see if any areas are harder to remove post dip.

The only way this would narrow down the issue would be a brand new screen.  One that hasn't had any chemical on it.  I am doing some r&d at a shop here in town that uses Nova the way Eric does.  I am trying to replicate the issue.  I'll post results.  On a side note Nova is a photopolymer not a dual cure.  The diazo is added to make the stencil hold up to WB Discharge ink with no added steps.  Eric call me today and let me know the parameters you are doing.

[Frog]

have you tested exposing a screen and putting it directly in the tank? no ink or cleaning before dipping.  That would narrow down the issue.  You could also clean little areas with different chems on a single screen and see if any areas are harder to remove post dip.

The only way this would narrow down the issue would be a brand new screen.  One that hasn't had any chemical on it.  I am doing some r&d at a shop here in town that uses Nova the way Eric does.  I am trying to replicate the issue.  I'll post results.  On a side note Nova is a photopolymer not a dual cure.  The diazo is added to make the stencil hold up to WB Discharge ink with no added steps.  Eric call me today and let me know the parameters you are doing.

Sonny, do you, or others, see the Nova bubblegum effect I mentioned? (btw, I don't dip)

[ericheartsu]

Sonny thanks for the info! sorry I posted it wrong! I'll call you on Monday!

Andy we've only ever gotten the stringy effect when it's been bad emulsion. Typically it just washes off, but it comes off in layers. For instance the ink side of the screen typically comes out with a single spray of our pressure washer, but the garment side takes several short blasts over and over again to really get it off.

[ericheartsu]

Also we tried some citra paste yesterday, and it didn't really seem to help.

Another thing we do, once screens are exposed they sit out in the sun to post expose. Sometimes for 15 mins, sometimes for 4 hours. Would it be hardening the emulsion to much that it can't strip down?

[Gilligan]

Also we tried some citra paste yesterday, and it didn't really seem to help.

Another thing we do, once screens are exposed they sit out in the sun to post expose. Sometimes for 15 mins, sometimes for 4 hours. Would it be hardening the emulsion to much that it can't strip down?

We do this... Probably not 4 hours.

Cross linked is cross linked I would think... At least when it comes to straight emulsion and exposure.

[ericheartsu]

when we coat our screens, we do 1/1 on the sharp side. I do the garment side first, then flip it and start from the bottom on the ink side.

Thats the correct way to do it right?

When we wash our screens out they aren't slimey on the ink side at all. They wash out with no issues at all