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screen printing => Screen Making => Topic started by: TCT on September 04, 2013, 07:47:57 PM
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How often are you guys degreasing your screen? After every wash? I just had a sales guy tell me that the only real time you need to degrease a screen is right after they've been stretched. Sounds odd to me.
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De-ink
Emulsion Remover
dehaze as needed.
We never use degreaser.
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Every time.
It's certainly not always necessary, especially when using certain haze removers, but I consider it the last line of defense and cheap insurance.
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Drop it from a few screens on the next run, rinse well and see if you have problems after coating, we did and never looked back.
We actually use dehaze on new mesh rather than degreaser, but emulsion still doesn't hang on 100% until the second run sometimes.
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Every time.
It's certainly not always necessary, especially when using certain haze removers, but I consider it the last line of defense and cheap insurance.
same here....it's cheap and easy to apply, not a big deal for peace of mind. from what I understand, dehaze actually removes a small amount of the mesh and makes it weaker so we only haze when needed. proper rinse seems to help the most...atleast the sales guy didn't tell you to use mesh abraider. ::)
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The simple answer is every time with a caveat. Use a "neutralizing" degreaser. This neutralizes the chemistry and returns the screen to a "Virgin" state. The simple truth of the matter is that most people really do not degrease properly. To really do it right you should rinse your degreased screen about 15 minutes. Not gonna happen. Inkwerks what will happen is in the future at some point your screen will not "Clear" on a print and all sorts of blame will be spread around. Truth is if you take a loupe and look at the mesh you will find it "blocked" by a chemical haze that is invisible to the eye. Granted this can take some time to show itself but it will happen.
Another major help is to always dry a wet screen horizontally mesh down.
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NEVER! what a waste of time! Dehaze only as needed.
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15 years plus now without degreaser, any build-up is handled by dehaze. We run two different dehaze, mild and, well, not so mild, as we use some nasty inks like epoxy and other solvent based stuff on occasion. A surfactant probably isn't going to remove chemical buildup anyway. Need for a degreaser would probably manifest in fisheye and the like in emulsion after coating.
The only problems we've ever had is with screens where the emulsion was treated with permanent fixer for wb/dc, and only if they sat un-reclaimed for a very long time. We've moved to Aquasol HVP and it's much better for reclaim so far.
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Looks like it is pretty well split. We use haze remover for stubborn stains but rarely besides that. The degreaser is cheep enough, but I was thinking more of the time aspect. Yes, it is not a whole bunch of time per screen but if it were to be eliminated along with not buying as much product, in a year I may save enough to buy a cigar, not a nice one, but who can turn down a Swisher Sweet :P
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We only degrease when a new screen is put into production. We used to do it religously at the end of the reclaim process but during the training of a new screen guy the degreasing step was left out, well, it was forgot about and after a few months I finally noticed my guy wasn't degreasing the screens and that's when we realized that it hadn't had any affect at all on our screens that was noticeable. So then I started testing and analyzing and I found nothing different between screens that had been degreased and those that had not. Even at 80X magnification there was nothing. True, it's cheap and it only takes a minute to apply and if you think it helps your screens then by all means do it. It would add 15-25 minutes a day to our production and I honestly tried really hard to figure out if it helped our screens even the slightest bit because we would continue to use it, but I couldn't see anything.
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I think it really depends on what you last step is before you would normally degrease. Some chemicals (dehazers specifically) have a degrease effect built in. HR6 supposedly does, but we don't like that product.
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Never. IMO unnecessary chemistry that has long since been outdated.
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Dip tank, spray out, easisolv 701, rinse, done.
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Our stencil remover has a degreaser. We use diluted simple green if clean screens sit around on the rack and gather dust, keeps the fisheyes away.
Never. IMO unnecessary chemistry that has long since been outdated.
Back when I was in the printmaking studio, we used diluted vinegar to 'neutralize' any residual chemicals. I skipped it more than once and never had problems--that I could tell. Of course, in comparison to now, I couldn't tell much back then. ;D
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I only degrease new screens to remove oils left by the manufacture, and sometimes after I dehaze...I think I have a gal that I bought 5 years ago.
Darryl
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i degrease after EVERY screen cleaning...i dont use haze remover unless i have a serious haze image in the screen which is next to never...I was taught, told and read that u MUST degrease after every reclaiming of the screen.
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Not necessary. Sometimes what we are "taught" is not necessarily accurate. Doesn't hurt but why bother?
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I have been told this recently also...So, what causes, and wadda y'all do about "fisheyes" ?
My reclaimer is having a serious on-going problem with this (amongst her other job quality issues)
I tell her to make absolutely sure that no drips are coming from "ceiling" of washout tank, or to hold it out to front of tank (past "drip line") while doing final rinse. I think a lot of the problem is her lack of attention to detail, I never had this many problems when I was doing it. Ideas?
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we have not degreased in years. was told we do not have to.
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Along the same lines, what are y'all using for pressure washers? (brand, psi, gpm) I have been kvetching for years about the cheap, low gpm flow units, the cheap bosses keep bringing in every 10 months or so.
I keep burning them up, and they keep on a' buyin em! "It's ok, we got an exended warranty!"
AAARGH!
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The most common cause of fisheyes is backsplash. More common with single sink scenarios. If one has the luxury of multiple sinks then a simple water rinse should eliminate the issue. In the screen room less chemicals=better.
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Along the same lines, what are y'all using for pressure washers? (brand, psi, gpm) I have been kvetching for years about the cheap, low gpm flow units, the cheap bosses keep bringing in every 10 months or so.
I keep burning them up, and they keep on a' buyin em! "It's ok, we got an exended warranty!"
AAARGH!
AR620, not a big fan of the wand, but it works well.
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We are pretty small 1 person shop, we reclaim about 6 - 10 screens at any time and always degrease, simply enough we use Dawn dish soap & water and a car wash brush that we keep away from other contamination. Takes only seconds to soap them up and hose them off, we do not get fish eyes unless we post wash splash the screens.
Also we also have found that when we have to spot hit a washed screen with the pressure washer to blow out a stubborn spot there is a noticible difference in the way the water drains off the reblasted area....we hit it again with the soap brush.
i have been thinking about testing Cascade dish washer soap for my degreasing stage just to understand the benefits offered there relative to draining / drying but have not got to try that out yet.
PS my pressure washer is a couple years old so it is not a result of contamination from a new machine and we are on municiple water.
mooseman
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We degrease EVERY time. Many years ago I was having trouble exposing low mesh screens. I was burning Ulano ProClaim for 40+ minutes on my 40w BL exposure. My screens were still showing signs of under exposure. I spoke to tech support from all the chemical companies that I was using, tested the bulbs and timer... I was going crazy. Doug Grigger asked me what I was using as degreaser. Well I wasn't. I never knew I should. Next screen exposed at 6 minutes and it have been smooth sailing for the last 10 years.
In my opinion it is well worth the extra 1 minute per screen.
Matt
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I think it's cheap insurance. I don't degrease if I'm reclaiming and screens are going right back to be coated, but once they sit for a day, they've turned into pumpkins as far as I'm concerned. A couple of specks of dust, and your halftone screen is a reject--and you may be contaminating your emulsion as well, if you don't run two buckets.
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Our screen rack/drying box blows filtered air into the box creating positive pressure so any door opening results in air coming out, not dust going in.
Zero fish-eyes here, but then we have a meticulous screen guy.
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We only seriously, actually degrease when mesh is brand new. There are lanolins/conditioners that need stripped off.
After that, we just spritz 'em with degreaser and rinse it around on the mesh right before final flood rinse and going in the box to dry, no scrubbing. Takes about 5s and less than a penny's worth of degreaser.
I don't see a need to scrub the screen with degreaser every time if the reclaim is done right. I do see a need to soap up a little and ensure the reclaim chem's are neutralized and rinsed clean of the mesh. The milder dehazers we use all seem to "stick around" a little in the mesh, especially since we rest them overnight with dehzer on. Also, screens stored out on the floor need a rinse/dry again before coating anyhow from the dust/lint accumulation.
So that's why we do it. I say if in doubt, degrease. If you test and you don't need it then screw it, rinse and straight to drying. We've always seen fisheyes when not doing it.
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I think it's funny, some guys -HELL NO, and others -all the time...haha. very last step for us is a mist of simple green or this other stuff called white lightning or some damn thing. deluded by 75% water and it takes all of 5 seconds to spray it on. we do a heavy rinse anyway so why not. I was reading some labels the other day and I do see that a ton of the haze remover are also a degreaser but we don't always haze...
after degreasing, we were hitting with compressed air and that stopped the fuzz but my in-line filter got a bit of oil in it...guess how awesome that batch of screens looked?! ...
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Dip tank, power wash, haze remover, power wash, rinse, coat (cap film) in the drying cabinet.
We have used degreaser in quite a long time. And we use capillary film. I haven't noticed any issues. We use either easisolv 701 or Franmar dehazer.
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We get fisheyes when we don't degrease, regardless of how carefully we rinse. I literally never dehaze though as no amount of ghosted image has ever affected one of our prints. Any idea why?
We use aquasol hv, easiway 500 to reclaim, pink stuff to degrease.