films leaving printer ink on screens

[Stinkhorn Press]

film output setup: accuink on imagestar (cheap nazdar) film. accurip single channel 720x720 at 15 weight or 1220x1440 if detail wanted

screens sit in heated vastex drying cabinet (low setting, 2/3) before being exposed. are in a heat/humidity controlled room before that.

exposure unit 5K MH. emulsion ulano proclaim diazo. roughly 40 sec to expose 110s. 30 sec for 200s. 70 and 80 sec if screens have face coats (new to us).

we can only expose about 4-6 screens at a time before the exposure unit gets too hot (it IS in the dark room, it's moving OUT in the next month or so).
and by too hot i mean it destroys the film by moving the accuink from the film to the emulsion. accuink is also a bit of a pain to wash out of a screen.
really really bad example attached (4th screen at 70+ seconds per, total destruction).

I know I could reverse my film output so the waterproof side touches the emulsion, but that seems like a bad idea, having the art the thickness of the film hanging away from the screen surface.
I could switch to a faster exposing emulsion, PP or some such.
those both seem like bandaids, not solutions.

would a higher quality film fix this?
anything else?

MH gets HOT. do you have a fan dedicated to cooling it down? i can't until i get the expo unit out of the darkroom, i don't much like fans in there.

[screenprintguy]

before we went CTS, this would happen when emulsion wasn't bone dry and the residual moisture in the emulsion would pull that ink off. Cranked our dehumidifier up and as long as we weren't rushing the drying of screens, like say at least over night for the coating to dry, it stopped. Could just be something simple like that. It was a pain though I know for sure.

[Stinkhorn Press]

before we went CTS, this would happen when emulsion wasn't bone dry and the residual moisture in the emulsion would pull that ink off. Cranked our dehumidifier up and as long as we weren't rushing the drying of screens, like say at least over night for the coating to dry, it stopped. Could just be something simple like that. It was a pain though I know for sure.

that's easy enough to try
we run a dehumidifer, but it's not cranked. unless it's even drier outside, usually hold 30-35% humidity in there. not good enough?

[cbjamel]

Reduce ink lay down percentage, to dry in winter. Put back up in summer.
I do, solves problem along with dry screen having some humidity in them.
Shane

[ebscreen]

Cool your unit down. I think the vast majority of exposure units aren't ventilated well enough.

If it's an Olec they have an optional ventilation setup they sell. We have a 6" inlet/exhaust with
inline fan on our 8K. Goes through the ceiling of the screen room, so no air/dust blowing around.

Of course none of this matters if your screens aren't fully dry as mentioned.

[mooseman]

Simply dust the screen with some baby powder and your sticking problems will go away.
Mooseman

[screenxpress]

Simply dust the screen with some baby powder and your sticking problems will go away.
Mooseman

^^^^^^

[DCSP John]

^^  talc will get rid of the tac.  ^^

[Prince Art]

...And reverse-printing so that ink is away from the emulsion instead of against it isn't a good fix. The thickness of the film creates enough of a gap between ink & emulsion that it can mean fine halftones won't blow out. (Learned this a long time ago when a film was accidentally burned wrong side down. All of the other screens in the 4cp job washed out perfectly, the reversed film wouldn't.)

[Frog]

...And reverse-printing so that ink is away from the emulsion instead of against it isn't a good fix. The thickness of the film creates enough of a gap between ink & emulsion that it can mean fine halftones won't blow out. (Learned this a long time ago when a film was accidentally burned wrong side down. All of the other screens in the 4cp job washed out perfectly, the reversed film wouldn't.)

Adding the thickness of the film chokes the dots. Trick we used to sometimes use on purpose when working with real films, generally when making contact prints of positives and negatives.

[Dottonedan]

before we went CTS, this would happen when emulsion wasn't bone dry and the residual moisture in the emulsion would pull that ink off. Cranked our dehumidifier up and as long as we weren't rushing the drying of screens, like say at least over night for the coating to dry, it stopped. Could just be something simple like that. It was a pain though I know for sure.

that's easy enough to try
we run a dehumidifer, but it's not cranked. unless it's even drier outside, usually hold 30-35% humidity in there. not good enough?

Don't trust the readings on the dehumidifiers. I've been in screen rooms that were large enough that they had 3 of them in there, (all the same) and each had different readings that were as much as 25% off from each other. Then we tested these, and sent them side by side. Same readings.
They do their job of removing the water in the air well enough, but they don't read accurate on the humidity.

I'll bet I've only seen one out of 50 be within 10% of accurate. It seems they put something in there that is about equal to a $5.00 item at Wal-Mart. The one I carried around with me wasn't even right. I quite trying with that after one or two times of finding out it wasn't even close. That was about a $20.00 item.

The ones I've seen work well and consistently, the shops had spend in the area of $50-$60.00 on at a Grainger or Home Depot. It's only a one time buy, every 5 years or so, so don't go cheap on it. And keep in mid, it's only going to be accurate within close proximity of where it's located. Not the whole room. Small rooms of 10x15 or less can sue one. Larger than that, get another.  Keep one near the drying area and one near the storage area.

In best scenarios, there is a coating room, a forced drying area such as a cabinet (inside) or separate from... a storage area, but I realize most don't have that room available.  It's defeating the purpose of having a storage area...if you introduce new wet screens into the same room. This is where people have issues with really old screens of 2 wks old or using screens that are not fully dried (due to not letting them dry long enough because they keep getting wet screens introduced. It should be at least an hour for drying well. If you need to use them faster. then you have too little numbers of screens. You can avoid that by using a drying cabinet and dry them faster so you can sue them faster....or, you can buy more screens.

[ebscreen]

Just yesterday finished an Arduino controlled temp/humidity gauge/controller for the exact reasons Dan outlines above.
Our commercial dehumidifier is sketchy at best in terms of accurately reading/maintaining humidity levels. I mean with
a knob you turn to dry/dryer/driest how do you really know? It's like the turtle and rabbit on ride-on lawn mowers.

I think Gilligan here did something similar and had it send data back to his computer which I'll get around to, someday.

[Prince Art]

Adding the thickness of the film chokes the dots. Trick we used to sometimes use on purpose when working with real films, generally when making contact prints of positives and negatives.

Yes, I've since encountered mentions of manual choke (is that the term?) being used back in the day. My own inadvertent experience taught me early on just how important it was to have good glass/film/screen contact. Helpful, since I was working with pro equipment at the day job, but cobbling together DIY equipment on my own... and trying to get "pro" results with it!

[Stinkhorn Press]

before we went CTS, this would happen when emulsion wasn't bone dry and the residual moisture in the emulsion would pull that ink off. Cranked our dehumidifier up and as long as we weren't rushing the drying of screens, like say at least over night for the coating to dry, it stopped. Could just be something simple like that. It was a pain though I know for sure.

cranked the humidifier, screens are exposing a bit faster, so there is definitely a change.

between that and the baby powder, the problem has been reduced greatly.

though as soon as i get the expo unit moved to the hall (waiting on guy to move the electric) i'll look into venting the olec bulb box - their way or kludged together with bits.

Don't trust the readings on the dehumidifiers. I've been in screen rooms that were large enough that they had 3 of them in there, (all the same) and each had different readings that were as much as 25% off from each other. Then we tested these, and sent them side by side. Same readings.
They do their job of removing the water in the air well enough, but they don't read accurate on the humidity.

I'll bet I've only seen one out of 50 be within 10% of accurate. It seems they put something in there that is about equal to a $5.00 item at Wal-Mart. The one I carried around with me wasn't even right. I quite trying with that after one or two times of finding out it wasn't even close. That was about a $20.00 item.

The ones I've seen work well and consistently, the shops had spend in the area of $50-$60.00 on at a Grainger or Home Depot. It's only a one time buy, every 5 years or so, so don't go cheap on it. And keep in mid, it's only going to be accurate within close proximity of where it's located. Not the whole room. Small rooms of 10x15 or less can sue one. Larger than that, get another.  Keep one near the drying area and one near the storage area.

In best scenarios, there is a coating room, a forced drying area such as a cabinet (inside) or separate from... a storage area, but I realize most don't have that room available.  It's defeating the purpose of having a storage area...if you introduce new wet screens into the same room. This is where people have issues with really old screens of 2 wks old or using screens that are not fully dried (due to not letting them dry long enough because they keep getting wet screens introduced. It should be at least an hour for drying well. If you need to use them faster. then you have too little numbers of screens. You can avoid that by using a drying cabinet and dry them faster so you can sue them faster....or, you can buy more screens.

good stuff. apparently there isn't much in terms of decent hygrometers (humidity readers).
http://www.bovedainc.com/store/tobacco/hygrometers/ - this one is digital and cheap and ADJUSTABLE. but so far i've only heard (online talk) that most hygrometers suck at accuracy below 40% (and that ALL cheap ones suck at the low ranges).
for total bonkers cost and accuracy you have http://www.abbeoninstruments.com/tools/item.cfm?code=1566&catid=518  ISO-9001 checked and it still comes with the disclaimer: Because these are mechanical instruments, they will not hold the ± 3% accuracy on the far ends of the scale (below 20% and above 80%).

next question - assuming a person COULD measure and maintain temp and humidity -
for a screen storage room (coated, ready to burn) what are the desired TEMP and HUMIDITY?

[Maxie]

I was told
Temp between 72-80
Humidity under 40.