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screen printing => General Screen Printing => Topic started by: Gilligan on October 18, 2011, 11:32:43 PM
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Ok, attached is a couple of pics.
One is of the 2nd screen, what you are seeing is the results of ink pickup from printing wet on wet (the black was printed first).
This is mostly one stroke and as consistent as my newbie ass can be. I reduced the off contact to probably under 1/4 of an inch, as little as I felt I was comfortable with.
This is a pretty new Pocono Mt. 158 screen coated 1:1 by a buddy's guy (professional).
The other picture is of the last print I made... this was a run of about 60 shirts... so not a lot but still a fair amount of buildup. My main concern/question is why does it always seem to creep in the same direction. The prints look good... but I can't help but know that I'm screwing up and I should be seeing this.
FYI, what you are looking at (if you can't tell by the fibers) is about a 1.5" by 1" graphic.
This is printed on an Antec Legend... using only one station and THAT station is fairly well setup (as good as my newbie self could do it.)
Any opinions, critics, words of wisdom, hand slapping would be appreciated.
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It actually looks like your screen moved.
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Hmm... now that you say that, I do notice that the screen comes out of the registration gates with an odd movement with that screen. I'll have to pay more attention tomorrow when I go out there.
It's always as I'm moving on so I don't think to pay attention.
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From the looks of your screen I am pretty surprised that you did not have ghosting of your print
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Agreed... granted, that is an extreme close up... but I think it was light enough not to really "stick" to the next shirt.
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The slightest off registered offset ink can ruin the next print. Most common when registration is changed mid run, and brain farts cause forgetting to wipe every other screen that have ghosts that now will not line up. Apparently not the case here.
But yes, it looks somewhat like your screen or the shirt moved.
As for wet on wet buildup, that's where the tightest screens really pay off, along with inks specified as wow. The standard band-aid fix has always been silicone spray or for you, and your usual choice of the cheapest, Pam.
It all goes to hell though if your screens or shirts move.
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I'm hurt Andy, really hurt. ;)
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When troubleshooting mis-registration close observation is the key to proper diagnosis. There is a definitive shift to the right which clearly indicates a screen shift. If for instance, the smear was equal in 360 degrees, then ink deposit issues would need to be looked into.
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Like others have said, it looks like your screen moved. But one other thing I'd like to mention that causes lots of ink spread at the edges of your stencil. That happens when you don't have proper EOM. I know that screen that was coated 1/1 doesn't have sufficient EOM to give the stencil a good edge to keep the ink in place. It spreads out causing ghosting in the direction mainly of your print stroke but you'll see it at the edge of the entire image as well.
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Also, if you push too hard you can get the same result.
I tried to show my brother how to push a squeegee (6'4" and 300 pounds) and he got the same result. I was afraid that he is going to break my pallet arms.
Off course, I have told him that he does not need to push hard (I can not imagine what would happen if I did not).
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anyone mention adhesive yet? could also play a roll.
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also when your put too much softhand in the ink to make it soft in the winter months
can cause this problem
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Some inks are just sticky as hell and the emulsion loves to catch ink as well....I know wipeing screens down is a pain but hey for a short run go for it. Oh yeah, you are looking to stop this problem, got an answer yet? and your not likely to get one but many many answers to many to even start trying... good luck. Ink build up is just one of those things that happen the only thing I know that stops ink build up is to flash every color and who in the world wants to do that, but some do that can.
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In this particular case however, as Tony pointed out, the "build up" does not seem to be normal build up since it is shifted to the side. Build up should be symmetrical on all edges.This looks much more like the screen or wet pint on the shirt shifted, and then the shifted image transferred to the screen.
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Sometimes a flood stroke (bad squeeze angles, etc.) can cause the ink to ooze from the other side of shirt side of stencil.
Does the problem go away after wiping the screen?
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Something like this happens to me when I'm flying through an order too fast, my screen will come down and instead of coming down between the the 2 nylon bolts (not sure how an antec works) I'll bring the head down and lay it on top of one of the nylon regi bolts and I'll make the print. This is on my RJennings press.
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well here comes that tension issue again, if your screens are loose and you push (or pull) with too much force you will actually "push-stretch" the mesh in a way that it actually shifts in the same direction as your print stroke printing the image a little off. You can check this by looking at the upper part of the design print closest to you starting point of the print stroke. Compare that to the lower part of the design print at the end of your print stroke. If the "off print" image is greater at stroke end than stroke start then you are "push-stretching" the mesh as it is too loose. If the print is equally off all arount , that is top & bottom then your equipment, screen, head, pallet, shirt or something is just plain moving bending or flexing .
You image looks like it is not very tall but you should still should be able to make a judgement as to the off print image relative to the intended actual image.
Hope this makes some sense......I am not know for making too much sense too much of the time :P
mooseman
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Also, if you push too hard you can get the same result.
I tried to show my brother how to push a squeegee (6'4" and 300 pounds) and he got the same result. I was afraid that he is going to break my pallet arms.
Off course, I have told him that he does not need to push hard (I can not imagine what would happen if I did not).
Problem is, I don't know what "too hard" is. I don't THINK I'm pushing too hard... I've always read about just "kissing" the shirt... and I TRY, but I'm sure I'm doing it much harder than that... but how much I don't know. :(
anyone mention adhesive yet? could also play a roll.
I use TexTac and rarely have issues... it was getting a little build up on it... but I had just put down some fresh tac before starting the job.
also when your put too much softhand in the ink to make it soft in the winter months
can cause this problem
I'm using straight Union Soft Ultrasoft HS.
Sometimes a flood stroke (bad squeeze angles, etc.) can cause the ink to ooze from the other side of shirt side of stencil.
Does the problem go away after wiping the screen?
No, it seems to consistently come back little by little and in the same direction. So I'm sure it's a shift of some sorts.
Something like this happens to me when I'm flying through an order too fast, my screen will come down and instead of coming down between the the 2 nylon bolts (not sure how an antec works) I'll bring the head down and lay it on top of one of the nylon regi bolts and I'll make the print. This is on my RJennings press.
Not possible... for two reasons... A. The Antec uses a dual gate system and bearings so if it misses the gate it won't even be close. B.) I can't "fly through" anything at this point. ;) I was able to print a shirt a minute (tiny bit faster) when I was timing myself for a few shirts just to see.
So, to touch on what I had mentioned earlier... I went look at how it was coming up in a strange way and it might be that I need to grease the floating point on that head... it's not causing the problem though. It comes straight up but then rocks a little (one side slides back then the other of the head). So obvious there is some consistent shift whether it is equipment fine tuning or human error (at least I'm consistent if it is).
Mooseman, I don't know about tension, these are wooden screens but they are pocono mt screens and they are fairly new. My understanding is that these are some of the better pre-stretched screens, but I have very little experience with these things.
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This is where side clamps could help...maybe? Whipping around screens too hard on a rear clamping system can push the screen out of registration. How smooth does it turn? Maybe you have the center shaft tightened too much?
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..
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It's beautiful... but I'll have to check it carefully.
Maybe I'll shoot some video of me printing so you guys can see.
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EOM... WOW... just exposed my 2:1 rounded edge coated screens and I'm just blown away of how much of a gasket I have on there.
I can REALLY feel the EOM on the shirt side... my buddy's 1:1 sharp edge stuff doesn't even really feel like there is a difference really.
I'm just amazed at how much difference that made!
Now, I can't wait to print on them!!
Gonna bring home the DSLR and see if I can't shoot some EXTREME close ups of the screens tomorrow.
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I do the glisten method and on a 158 mesh that would usually be 3 to 1 coating on the rounded edge. Basically on the shirt side you coat your screen until it shines on the other side and finish off with 1 coat on the ink side.
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Not enough spray tac, pushing to hard, loose palette, loose micro knobs.
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Well, I did another set of these shirts (youth and toddler)... at first I had problems and I knew I would. THAT pallet arm (not the same one) isn't very tight on the bearing gate. Not sure how I can adjust that. Might just see if there is some fudge room on tightening those bearing bolts. I printed essentially one shirt and knew I had to do something. So I put some aluminum tape on the flange that goes in that gate and that tightened things up well and I never had an issue on the entire run 60 shirts. So I'm guessing I'm getting a little wiggle on the other arms too.
Not sure what I should do about that as there are no adjustments. Antec Legend. Guess I'll have to give those guys a call once I really get setup and have all my arms on and know what is what.
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Well, I did another set of these shirts (youth and toddler)... at first I had problems and I knew I would. THAT pallet arm (not the same one) isn't very tight on the bearing gate. Not sure how I can adjust that. Might just see if there is some fudge room on tightening those bearing bolts. I printed essentially one shirt and knew I had to do something. So I put some aluminum tape on the flange that goes in that gate and that tightened things up well and I never had an issue on the entire run 60 shirts. So I'm guessing I'm getting a little wiggle on the other arms too.
Not sure what I should do about that as there are no adjustments. Antec Legend. Guess I'll have to give those guys a call once I really get setup and have all my arms on and know what is what.
The arm should be held by 4 bolts, I do not know how you have any wiggle room.
Mine do not move at all.
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No, not the arm itself but the flange or tang? that drops into the bearings. There is space in between the bearings and the metal tang (is that even right?) that slides between them. Granted not much, but as we know it doesn't take much down there to produce too much further down the arm.
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No, not the arm itself but the flange or tang? that drops into the bearings. There is space in between the bearings and the metal tang (is that even right?) that slides between them. Granted not much, but as we know it doesn't take much down there to produce too much further down the arm.
You might need a new set of bearings :(
Does that "flange" thing look worn out?
Call Dave Paterson @ Antec, he will help you out.
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Hard to tell... it's definitely seen some wear but there is gunk buildup that doesn't like to come off of that thing.
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Are the bearings eccentric? IE if you undo a set screw on the mounting and rotate them they offset one direction
or another?
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Hell, if the press operator had money, he'd be labeled as eccentric!
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Wouldn't we all.
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That's what I was thinking... And I'm referring to both of you guy's comments.