TSB
screen printing => Screen Making => Topic started by: rmonks on November 19, 2012, 07:30:06 PM
-
Anyone use two dip tanks one for the ink removal and the other for the stencil. Just curious, looks like you could get more mileage out of the chemicals but just asking.
-
I asked this a couple of months ago, and I think that eb said he was considering it since he had a spare tank. (either that or using his second tank for pre-soaking before development rinse-out).
Let's see what he decided.
-
..I use two tanks, but one is used the standard way while the other is a development pre-soak, as frog described.
..I really doubt a tank devoted to ink removal would do anything. The ink removal requires some mechanical agitation. The trick with dip-tanks used the normal way, is that the ink is sitting ON the emulsion, and gets carried away when the softened stencil is blasted from the screen. In fact, my dip-tank has NO ink removal content whatsoever; I use the crystal concentrates to make my own. Why ship water?
...I think that, without that physical agitation, the extra dip in a ink-remover-only tank would not save the stain removal step afterwards, which I assume is what you are trying to accomplish.
-
I am wanting to eliminate the spraying ink degrader and scrubbing process I thought I might soak screens in ink degrader and then power wash then dip in stencil remover.
-
I have the second tank and the solution to set this up, but have not had the time to get it going.
First tank will be the ink degrader, then a quick power wash, than Supra. The idea is that the first tank will remove 99% of the ink, then a dip in the second one will eliminate the need for the 701 scrubbing.
We tested several chemicals to fill the first tank and RTU from Nazdar is going to be our first try.
One of the reasons we are looking to do it this way is to save the potency of the Supra. It should also be a little cheaper as RTU is much less money. On top of it all, I am hoping to see some time savings too.
Might not get to it until Jan though . . .
pierre
-
I do ink removal from a pour spot and scrub it, blast off, into the tank to strip emulsion.
We have a plain water tank for resolving. Highly recommend.
I doubt the efficacy of an ink remover dip, you just gotta scrub.
-
We use 2 dip tanks.
one tank is filled with water, and our screens go right into it after we expose them, then we pressure wash them out.
the other is emulsion stripper.
solid plan
-
How long can a screen sit in there till its time To develop?
Walt at Murakami recommended against this as he thought the emulsion would get to soft and suck up to much water.
On a side note I've been tinkering with adding an air hose with a small amount of air to our reclaim dip tank to add Agitation thus making the spray out faster.
-
How long can a screen sit in there till its time To develop?
Walt at Murakami recommended against this as he thought the emulsion would get to soft and suck up to much water.
On a side note I've been tinkering with adding an air hose with a small amount of air to our reclaim dip tank to add Agitation thus making the spray out faster.
Totally depends on the stencil but if it's gets soft in the tank it was in there too long. This is probably a bigger ROI than a chem tank, it's worth checking out. I won't ever go back to standing there hosing a screen again. We dunk in the water tank up to four at a time, pull them out and use the press washer on fan spray. Rinse with hose, soak up excess water and back in the dry box. It's all done stupid fast in comparison. Big benefit on all screens from the 90/71 coated 2/2 round edge to the 330/30 1/1 thin edge with 60lpi 'tones. I don't know Walt, but he oughta know better- he's right in that some emulsions are too "soft" for this but Aquasol HV is perfect for it. A big part of why I use Aquasol is that I can dunk tank it and use the press washer on it.
The CCI Gemzyne in our strip tank would be too damn fast with agitation, I don't like to let any solids actually slough off the screen in the tank. It knocks it down pretty quick. I see there are some units out there with agitation but I think they are for super-high throughput shops with a crew working all day on the task. It's likely overkill outside an environment like that whether it's for stripping emulsion or resolving stencils.
-
It's already been said but I think the second dip tank would be better served as a stencil developing tool than an ink degrader. We remove ink from screens before we dip and it works so much better than not doing it. Our chem has lasted twice as long since we've done it this way. I guess the ultimate would be 3 dip tanks!
-
I've tried the "ink degrading tank" waste of time, money and chemicals. We do use 2 tanks, one like others is plain water for developing right out of the exposure unit. We de-ink with beeniedoo and then screens are staged for the diptank for final reclaiming. For instance, my guy last week did 44 screens in a 5 hour shift, that was from carding off inks into the proper pails, re-shelving the pails, de-taping, de-inking, dip tanking, pressure washing, and final de-hazing, degressing, and racking. For us, that's pretty good. We still use squirt bottles for ink degrader, stain remover, and de-greaser, but have been thinking about an albatross 3 stage spraying system.
-
It's already been said but I think the second dip tank would be better served as a stencil developing tool than an ink degrader. We remove ink from screens before we dip and it works so much better than not doing it. Our chem has lasted twice as long since we've done it this way. I guess the ultimate would be 3 dip tanks!
we do have a 3rd tank for developing. Just like the 2nd it is sitting and waiting for us to get our s@$%$ together!
pierre
-
I've tried the "ink degrading tank" waste of time, money and chemicals. We do use 2 tanks, one like others is plain water for developing right out of the exposure unit. We de-ink with beeniedoo and then screens are staged for the diptank for final reclaiming. For instance, my guy last week did 44 screens in a 5 hour shift, that was from carding off inks into the proper pails, re-shelving the pails, de-taping, de-inking, dip tanking, pressure washing, and final de-hazing, degressing, and racking. For us, that's pretty good. We still use squirt bottles for ink degrader, stain remover, and de-greaser, but have been thinking about an albatross 3 stage spraying system.
what did you use for ink degrader? we tested several chemicals and most of the cheaper ones did not work very well. I guess we could always go to two tanks of Supra (since it works well as degrader), but that's expensive.
pierre
-
I think that you guys looking to partly automate the process with cleaner/degrader tanks may want to look into the next level, the recirculating units that actually do something with the crap.
-
when we did that,we used the EasiSolve 701. Filling a tank with that is super expensive. Now don't get me wrong it loosened up the stuff a bit, but too long in that will jack up any emulsion if soaked too long, had that happen, and in the end, we still had to scrub hard and use more spray on with any heavier inks, like white, or any max opaque type inks. Thinner inks that leave little to no residue behind weren't such an issue, but even if you use those thinner inks mostly, 2 squirts and a quick scrub and they come right off with something like beenie doo. It's just what we have worked out to be a nice productive flow back there.
-
I'm glad to hear about the developing tanks being a good step. I'll get the guys setup with that when we
get back next week.
I had the same concern as Jamie, leaving it in too long and softening the emulsion. Seems like
it could still happen but that would be on us and not the process.
-
yeah the develop tank is awesome, when I got the Richmond, my screen exposures got so fast, I'd out pace my wash out, so now, I drop them in the tank right next to the exposure unit, if a couple of them are in there is fine, when I get to rinse them out, if the emulsion didn't already fall out of the image, normal water pressure will get it. I still use the washer, real light and quick. It's great for sim process screens, you don't have to beat on your emulsion to wash out the image, makes it faster and cleaner all around for us.
-
I noticed a huge improvement in the halftone resolution from using the water tank. Even with the good backlighting in our "clean" booth it's pretty hard to gauge what's going on in all areas of a higher lpi screen. Using a controlled amount of pressure washing after the soak helps you get it all resolved without reefing on one particular area and blowing it out and without screwing around for 10 minutes with it.
I'm brutal about screen resolving- if you can't dunk it in a soak tank, blast it with the washer for 30 sec and have it come out perfect, something needs adjusted until you can. There's no sense in messing around here.