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The last few screens I've made, I've had a problem with the ink from the transparency sticking to the screen while removing the transparency from the screen after exposing it. I haven't changed the way I'm doing anything, at least nothing I'm aware of.

Now, I'm still able to use the screen.. I just have to scrub the printer ink off with a paper towel before I wash out the design, and then if I use enough water pressure, I can get the rest out. The few spots remaining can be removed after the screen has dried.

Of course, this means I can't reuse the transparency. Any ideas? After coating the screens in emulsion, I'm drying them for about 2 hours in front of a fan at high speed.

stumped :confused::confused:
 

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Are your transparencies completely dry?

Try drying your screens longer too. Overnight if possible. Humidity, especially this time of year with all the rain we've had, will have an effect on drying times of your emulsion.
 

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Couple things it could be that have happened to me.

1) One of the sides of some transparencies holds ink better than the other side (on some brands). Usually says on the packet.

2) I use an epson 1400. I usually have it set to Dark. Sometimes if the areas that it is printing are big, I need to turn it down because the ink tends to puddle a little.

I don't even think you need to wipe of the emulsion. I've always just developed it and washed it out and the ink comes right out with the undeveloped emulsion that it was sticking too.

Good luck!
Nick
 

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This has happened to us as well. We couldn't allow our screens to dry any longer, nor the film, we don't have that luxury most of the time. I got some baby powder and sprinkle it on my fingers and lightly rub the area of the screen that the film is going on and it won't stick. This problem comes and goes at our shop, most likely humidity and not enough drying time, although we have a dehumidifier and a heated dark room it still happens to thick stenciled screens.
 

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I've recently switched over to Ulano's new orange emulsion from QX-1... I love it. Exposes quicker & the stencils appear to be stronger, but I notice some ink from my film to be sticking to the emulsion. I've dried both my screen & positive overnight, but I live in Hawaii, so it's pretty humid. Would slightly over-exposing my screen possibly be the cause?
 

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I too have used baby powder to stop having this happen, the thicker the emulsion the tackier it gets. Be careful not to over do it though or you'll be using the block out pen for awhile.
 

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This is one of the many reasons I went to vellum. Printing out on vellum is just like printing on paper, the ink is dry right out of the printer. Added two minutes to my exposure time and it works great.
 

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I print with more ink on waterproof film then most and don't have any problem with ink coming off and I can print and expose within a few min. The ink is coming off cause emulsion is not properly dry. If you don't have a dehumidifier or AC to keep the humidity lower the 40-45% it don't matter how long you dry the film ink will transfer. The humidity soaked emulsion will take longer to expose and a higher chance of image blowout.

I expose @ 45 sec-1:30 with photopolymer on a blacklight unit and wash out with a power washer. With vellum it increases to 3:00 and still slightly under exposed as the the extra opacity of the vellum and have to wash out with a hose as emulsion isn't fully cross linking as not enough UV light is getting though. I'd like see a photographic or very detailed image exposed at 65-75 LPI and washed out with power washer with vellum.
 

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Also, what exp unit are you using? The heat from a 500w halogen will cause this if you don't use a fan.

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You should reverse your design before you print. This way the ink of the transparency will not be against the screen. Ive had the same issue before.

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You should reverse your design before you print. This way the ink of the transparency will not be against the screen. Ive had the same issue before.

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This creates a gap between the emulsion and film which can promote under cutting. Not a huge problem with spot colors but with halftones you can loose a lot of detail.
 

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I've started having this issue since using a different emulsion to my norm. Not just films sticking to the emulsion but also the emulsion sticking to the glass. Pinned it down to excessive heat, keeping a fan running on the lamps/glass seems to alleviate the issue.
 

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Hi

Have to say guys I have been in this industry for 27 years, I have in that time seen the development of Positives from cameras to inkjet printers.

I have also used many varities of Diazo emulsions for my screens, and I would like to make it perfectly clear that if the screen has been properly cleaned and coated, that once it is thoroughly dry the positive should not be sticking to the screen. If it is, the fault lies entirely with the positive, look at the printer, the ink and the film used.

Coated screens do not have to stand for a period of time before being used.

Debbie
 

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This is a problem with inkjet films in conjunction with pretty much any photo-polymer emulsion. Photo-polymer emulsions dry very smooth and flat on the screen so when you go to burn your screens with the blanket forcing down on the screen, any moisture left in the screen will be pressed against the positive causing the ink to transfer to the emulsion and the sticking.

There several ways to address this:
1. Use a dual cure diazo emulsion.
2. Slight bit of baby powder on the positive (ghetto, but works)
3. make sure you screens are as dry as possible
4. invest in a dehumidifier (may only help though)
5. Make sure your ink droplet is not set too dense and is fully dry

:)
 

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The baby powder trick has worked perfectly for me. Just dust a little over the screen surface then wipe away with a dry tissue. It reduces the emulsion surface friction just enough to solve the problem without interfering with tape adhesion. :)
 
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