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screen printing => General Screen Printing => Topic started by: im_mcguire on March 01, 2018, 02:34:18 PM
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So this is my Workhorse Cutlass:
My specs are as follows:
Pneumatic Head at 85 on the regulator
New 70/90/70 squeegee at 10-15 degree
156 mesh with tight tension streteched from Spot Color Supply
White ink Warmed up for 15-20 minutes
IC Blaze cotton white
I need 3 strokes to clear this thing...
any help is appreciated.
https://youtu.be/WTihy60AgBY
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looks like your squeegee is dull? or your screens are not clean enough
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Flood slower and lower the flood bar to fill the image.
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Flood slower and lower the flood bar to fill the image.
about to say this too...stand that blade up a bit more. looks like you're not filling the ink well and using the squeeegie to fill the screen and pump the ink through.
* the small text "Credit Union", is that the way the font is or is the screen not washed out properly?
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Flood slower and lower the flood bar to fill the image.
about to say this too...stand that blade up a bit more. looks like you're not filling the ink well and using the squeeegie to fill the screen and pump the ink through.
* the small text "Credit Union", is that the way the font is or is the screen not washed out properly?
The small text has a slight stroke on it, and should look like that. Ill try and fill it more, and post results here in a minute.
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Also, is there a physical depth adjustment on your squeegees?
85 psi would bend a 90 duro squeegee in half.
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Looks to me like shitty ink, either partially cured or with pigment clumping together. Can you print the exact same ink and screen manually without any issues? Like literally take it off the cutlass and put it on a manual press and print it.
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I know you said you mixed it good. But the ink is still not flowing. You need to use a reducer by 5-10 %.
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Also, is there a physical depth adjustment on your squeegees?
85 psi would bend a 90 duro squeegee in half.
This is a picture of the depth settings. The squeegee is maxed out, and we typically adjust the regulator as needed
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Your angle might be off.
Also, your flood isn't that great, and could be causing some of that issue.
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Looks to me like shitty ink, either partially cured or with pigment clumping together. Can you print the exact same ink and screen manually without any issues? Like literally take it off the cutlass and put it on a manual press and print it.
This is a new 5 gallon I got not too long ago. Trust me, I know I am not looking to do 1 hit whites, but even with the Wilflex Lava white, I have had these same issues.
I even use 150 S mesh, and have issues with 2 strokes, sometimes not clearing all of the way.
Ill take this off press now, and see what it does on my manual. This has been a fighting issue since we got this press, and just hearing everyone and how they run, it makes me think there is something I am doing that is wrong.
My flood bar if I lower it any more, it will scrape against the shirt, so if I had to double stroke the white, it would blur the first image.
Maybe the reducing of ink is whats needed.
I have tried a 5 gallon of the following inks, with each at least needing 2 hits, most of the time 3 strokes:
Rutland Cotton and Low Bleed Street Fighter 2
Wilflex Lava White from Ryonet
Rutland Peak White
IC Blaze Cotton White
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it seemed in the video that the print is not peeling. not sure if that just looked that way, but if it is the case, you would need more off contact.
also, just to be on the safe side, get some Joe's ink. If you can't get that to clear, it is not the ink.
pierre
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It may not pertain to this particular problem.... but I've switched over to exclusively S-mesh and find I get much better clearing.
And, I think, smoother prints due to less lifting of the ink when the mesh snaps back up.
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It may not pertain to this particular problem.... but I've switched over to exclusively S-mesh and find I get much better clearing.
And, I think, smoother prints due to less lifting of the ink when the mesh snaps back up.
Us also on the s mesh and what a difference. It was well worth the switch, when i had standard mesh, a 156 would always take 2 strokes and now a 150 is one and done.
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First, I would suspect a bad screen. Second, I personally hate triple durometer blades for White.
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85PSI is more than enough energy to push that ink around. I agree with ebscreen, that's enough pressure to fold the blade in half and be gouging the aluminium squeegee profile through the rubber on the plattens.
I'd be inclined to back the air pressure off to 40PSI and adjust the physical height of the squeegee back off and start lowering it so it's hitting nice. 40PSI for what it is, is well more than enough to print with, especially that image, there's practically nothing to it. Depending on the image itself I don't see any wrong in a first up double stroke, but I don't see a situation where you'd ever need anymore than that - Having to hit something 3 times says there's something wrong.
I can see more ink film left on the stencil surface than I would expect to see out of a new squeegee too. Not drastically more but I'd be expecting less.
It seems to me there's a whole excess of pressure that isn't balancing right.
The "max out squeegee depth and rely on pressure alone" isn't something I personally agree with. I'd given it some thought in the past and figured it was a way around getting uneven pressure from uneven pallets. It's probably a sound theory but I instinctively go the other way - Level/even pallets, consistent air pressure and adjust squeegee depth to be printing + a touch more. But that's the graphic/flat sheet printer in me.
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Your 70/90/70 squeegee is bending plenty. Its not a chopper issue.
As long as you have off contact and your screen is snapping back right behind your squeegee, everything is fine there. The comments about procedure with whites inks are always good to follow.
Are you having this issue with EVERY white you use?
Looking at how the ink is clearing on each print stroke..... My thoughts are that you are not fully exposing your image and getting a bit of scumming in the image area, but the "over exposure" look of credit union makes me think otherwise.... Unless you exposure unit has a weaker light source.... White mesh screens?
What is your exposure unit? Solid films? Do you have a perfect vacuum or do you have air leaks?
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Try Hard Flood? Make your squeegee almost vertical. Got any 65/90/65?
Rutland premier white
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Im calling it a day for today, but I will have a job tomorrow that is set up on a 150-s mesh base, and 180 s-mesh top white.
Ill post details of what I am expierencing, with those mesh, and Ill switch my ink to my only other white I have in the shop (QCM Creamy Glacier White)
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I print manually, but for my whites on 135S and 150S I can literally fully clear my ink with just enough pressure to touch the shirt, like barely any at all. Unless your inks suck or you have crap in the mesh you shouldn't need much pressure at all to clear the ink in a single hit. I almost wonder if the pressure is so high that the squeegee is bending to the point of skimming over the image and not actually pushing or sheering ink through it.
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I almost wonder if the pressure is so high that the squeegee is bending to the point of skimming over the image and not actually pushing or sheering ink through it.
This was my initial thought...too much pressure, maybe stand the blade up more, and too slow.
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My first thought was off contact. Next thought is shitty ink. We got a 5er of Sprint white that is just poo. Can`t print with it proper as it stays thick no matter what.
I would probably make the ink a little thinner and work on the off contact.
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Here's my take...
1. Your ink seems fine. If you are having problems with all different types, it's not the ink.
2. Speed that squeegee up. That is way too slow. I would increase by at least 50%.
3. Take out some pressure. Cut that at least in half.
4. Stand your squeegee up more. It should be more vertical than that. I would say 5% angle range.
5. Take off some squeegee depth when you do that.
6. Check your off contact. It may be too high and you are warping the holes in the mesh and not allowing the ink to travel through easily. Or it's too low nad you aren't peeling the ink film cleanly.
Your screen should be cleaner when the press prints. I think your pressure/squeegee depth is way out of whack.
Sonny always jokes that if you think you know what to do to fix a print, try the opposite and that usually works. Even now I still apply that guideline and I surprised how often it works.
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For everyone mentioning the pressure, when workhorse installed our machine they mentioned to me that white inks should be about 80 and everything else about 60. I'm not sure if it's the way they set up the machines that it doesn't transfer over to the same pressures on an M&R machine. Sounds goofy, but my M&R buddies told me to try it at 30psi and it looks like the squeegee just wipes over the screen.
I've always wondered about that as well.
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For everyone mentioning the pressure, when workhorse installed our machine they mentioned to me that white inks should be about 80 and everything else about 60. I'm not sure if it's the way they set up the machines that it doesn't transfer over to the same pressures on an M&R machine. Sounds goofy, but my M&R buddies told me to try it at 30psi and it looks like the squeegee just wipes over the screen.
I've always wondered about that as well.
That may be true but it seems that 80 psi would throw your pallets out of whack on being level.
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I'll toss in another guess. How well are you washing out your screens? I mean, could there be any haze left over? Excessive ghosting and buildup? Might want to look at the mesh opening under a loop on a dry screen (all over the print image area). If you see a lot of gunk in the cracks/knuckles combined with a slight haze, could be blocking mesh opening a tad.
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Ok. So I think we had a combination of poor ink, and improper screen selection. With everything that was being said, we looked at every suggestion.
We finished this job, and moved on to our next one that was set up as a 1 color white on the front.
We ran a 150 S mesh for the base and a 180 S mesh for the top white.
Though I could have got it pretty close with 1 stroke, my ink laid better with 2 strokes on the Tri Blend shirts we were printing.
I’m now a firm believer of all bases on S mesh screens now.
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What Brad said. Also a double bevel squeegee. This falls under my "Physics of Screen Printing" course. Your issue is improper use of the ink to screen.