Author Topic: Films sticking to screen after exposure  (Read 10361 times)

Offline ZooCity

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Re: Films sticking to screen after exposure
« Reply #15 on: May 14, 2015, 10:30:32 PM »
For the first time ever, we are dealing with this now.  It's actually ripping emulsion off outside the image area so wrecking the screen and the film...ugh.

It's too dry here for it to be environmental, screen cab is easily 14% humid most of the time and overnight drying the films has not improved it.  I think it happens when we're 10 screens in on burning.  It's the LED unit ironically.  I temped it today at 104˚ on the outside of the rubber blanket.  Having our screen tech watch temp tomorrow and find the point where it's tipping over from "a little warm" to screen/film bummer. 

So my guess is look at the heat first but absolutely +1 to everything else mentioned. 

This is dual cure or, diazo added PP by the way.  Our current PP emulsions are actually a little more 'matte' in finish.


Offline Binkspot

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Re: Films sticking to screen after exposure
« Reply #16 on: May 15, 2015, 05:41:39 AM »
For us the only time we have the sticking issue is the humid summer on days it's almost humid enough to rain but doesn't or if I forget to empty the dehumidifier and only on screens we are using PHU or Kiwo Discharge. We use WP film from Spot Color or Nazdar and Cobra ink, films are usually at least an hour old drying in the office. That being said our screen closet is kept at 90-100 degrees and 30% humidity year round.

Offline mk162

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Re: Films sticking to screen after exposure
« Reply #17 on: May 15, 2015, 08:26:39 AM »
brian...why are you emptying a dehumidifier?  I would figure somebody as carfty as you would figure a way to fix that.  Ours drains into an HVAC condensate pump, which in turn pumps it up to an overhead condensate line that was running from a different suite to the back of the building.

Offline Binkspot

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Re: Films sticking to screen after exposure
« Reply #18 on: May 15, 2015, 08:35:43 AM »
Figured someone would call me out on that, I'm too cheap to buy a condensate pump plus it's about a 100' run around the shop for the hose to reach the slop sink.

Offline mk162

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Re: Films sticking to screen after exposure
« Reply #19 on: May 15, 2015, 09:21:12 AM »
i figure it's easier than depending on somebody to remember...or a spilled bucket of water...either way, it's a pain.

Offline Itsa Little CrOoked

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Re: Films sticking to screen after exposure
« Reply #20 on: May 15, 2015, 09:39:25 AM »
I've done 7 years coating 2 over 2 with the SHARP edge and I had almost no problems with sticking.

I also had ZERO EOM...or none to speak of!

Now that I have an auto I'm trying for the elusive One Hit White because otherwise I'm stuck in revolver mode on some jobs. I have one flash and only 8 heads, so I REALLY need to get my EOM up. But this sticking thing is new, and it's driving me nuts.

Before I had a dehumidifier in my screen closet, I used to spray the Fixxons films with Krylon Matt Clear during rainy weather. I may have to go back to that, but I'm not even sure that will work, its been so bad lately!

And it's raining AGAIN this morning in Wichita.  !@#$%^&*!!

I've got to try either that whole cumbersome Matt Clear thang again, or new emulsion or give up on EOM. Or get my NuArc 2125 cooler somehow.

Or drive to Arizona to expose my screens.

I'm not big enough for a CTS or DTS or whatever the name is this week.
« Last Edit: May 15, 2015, 09:43:10 AM by Itsa Little CrOoked »

Offline Orion

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Re: Films sticking to screen after exposure
« Reply #21 on: May 15, 2015, 10:04:53 AM »
Anyone here have their exposure unit housed in a climate controlled screen room? Ours is. Back when we used films we did not have the "sticking" problem.
Dale Hoyal

Offline mhprinting

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Re: Films sticking to screen after exposure
« Reply #22 on: May 15, 2015, 10:29:19 AM »
I've done 7 years coating 2 over 2 with the SHARP edge and I had almost no problems with sticking.

I also had ZERO EOM...or none to speak of!

Now that I have an auto I'm trying for the elusive One Hit White because otherwise I'm stuck in revolver mode on some jobs. I have one flash and only 8 heads, so I REALLY need to get my EOM up. But this sticking thing is new, and it's driving me nuts.

Before I had a dehumidifier in my screen closet, I used to spray the Fixxons films with Krylon Matt Clear during rainy weather. I may have to go back to that, but I'm not even sure that will work, its been so bad lately!

And it's raining AGAIN this morning in Wichita.  !@#$%^&*!!

I've got to try either that whole cumbersome Matt Clear thang again, or new emulsion or give up on EOM. Or get my NuArc 2125 cooler somehow.

Or drive to Arizona to expose my screens.

I'm not big enough for a CTS or DTS or whatever the name is this week.

I'm in the same situation you're in.  Ever since with the auto, my films have been sticking.  Would a drying cabinet help?

Offline Binkspot

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Re: Films sticking to screen after exposure
« Reply #23 on: May 15, 2015, 10:48:23 AM »
All our screen making is out on the production floor, screens are kept in a light safe environment

Offline Itsa Little CrOoked

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Re: Films sticking to screen after exposure
« Reply #24 on: May 15, 2015, 11:16:49 AM »
I'm in the same situation you're in.  Ever since with the auto, my films have been sticking.  Would a drying cabinet help?

Nope.

I already use a drying "closet" for storage. They dry in there and just stay in racks until I need them. I can push it down into the low 20% RH range or even mid teens if I want (although the temp approaches 100º if I'm not careful) It makes no difference.

This is just a last few days phenomenon for me, just since I'm trying to get some EOM.  If I went back to sharp edge coating 2 over 2, I'm golden...with my current setup. After seeing Kitson's setup, my whole gig is decidedly "ghetto" and I'm not going to keep making the same mistakes over and over and over. I'm inspired to streamline and improve. Determined, really.

I told Greaves I DON'T have 7 years of experience. I've had 1 year of experience, 7 times.

Them's the facts.

All our screen making is out on the production floor, screens are kept in a light safe environment

Yeah Brian, me too. I'm cramped for space. I had to snicker when I read Brad's "different suite" comment above. I call my print floor a dungeon. I wish I EVEN HAD a suite! All in jest, Brad!  :)  If I had room, I'd copy Kitson's screen loop, except I am pretty much stuck with films.

Until the emulsion is dry, there is zero problems with exposing them with all the UV energy you care to muster. I think you can probably spoil diazo powder with UV energy, but that's a different topic.

Stan

Offline Gilligan

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Re: Films sticking to screen after exposure
« Reply #25 on: May 15, 2015, 11:19:15 AM »
Hey Stan, what emulsion are you using?

We saw sticking with Chromaline Chromablue... less so with Kiwo Onecoat... though I noticed more sticking when we started playing with longer exposures and my bulb is getting old... so I think heat is starting to create part of the issue for us as well.

Offline Itsa Little CrOoked

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Re: Films sticking to screen after exposure
« Reply #26 on: May 15, 2015, 11:33:48 AM »
Kevin, I'm using WR 25  (CCI) and my blub is getting old too. I've got a new one in stock, so what is my excuse?? Dunno.... Busy texting to convince a self-diagnosed Arrhythmic Musician not to give up maybe? Ahem.

But I digress.....

I think heat is definitely part of my predicament. That and I'm basically starting over dialing in exposures. And trying to hold low percentage dots.

I wish I could see a video of someone using a Stouffer 21 Step Exposure Guage who knows how the heck to use it properly! Cause I can't figure it out. I wash out WR-25 from both sides and it utterly destroys any information the Stouffer might lend.

Offline dj

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Re: Films sticking to screen after exposure
« Reply #27 on: May 15, 2015, 01:51:21 PM »
Try this, first when you print your film print a mirror image. This allows you to put the slick (non printed) side of the film against the screen. Then lay a clear sheet of plastic film slick side up on your exposure glass, this allows the ink to be in contact with slick side of film facing light. This has worked for us for years.

Offline Frog

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Re: Films sticking to screen after exposure
« Reply #28 on: May 15, 2015, 02:54:57 PM »
Try this, first when you print your film print a mirror image. This allows you to put the slick (non printed) side of the film against the screen. Then lay a clear sheet of plastic film slick side up on your exposure glass, this allows the ink to be in contact with slick side of film facing light. This has worked for us for years.

Though not huge, this will cause a little choke on positive dots and spreads in the voids. No biggie once you figure it into your dot gain calculations.

We old timers have, more than once brought up these stoneage camera techniques for pre-computer era film output and screenmaking.
That rug really tied the room together, did it not?

Offline Gilligan

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Re: Films sticking to screen after exposure
« Reply #29 on: May 15, 2015, 03:56:46 PM »
Kevin, I'm using WR 25  (CCI) and my blub is getting old too. I've got a new one in stock, so what is my excuse?? Dunno.... Busy texting to convince a self-diagnosed Arrhythmic Musician not to give up maybe? Ahem.

But I digress.....

I think heat is definitely part of my predicament. That and I'm basically starting over dialing in exposures. And trying to hold low percentage dots.

I wish I could see a video of someone using a Stouffer 21 Step Exposure Guage who knows how the heck to use it properly! Cause I can't figure it out. I wash out WR-25 from both sides and it utterly destroys any information the Stouffer might lend.

I'm gonna forward you an email I had about that stouffer strip the other day... Still no real answers that we have acted on, but some more insight.