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screen printing => Newbie => Topic started by: Racer Tees on November 24, 2014, 03:54:47 PM
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Been having an issue when trying to run some prints wet-on-wet. The first color printed on the underbase looks fantastic, but each color after begins to stick the screen to the shirt and the print becomes blurry. It is a 5 color job, all screens are between 23-26n except for the 3rd screen which is at 15n. I dont think that lower tension screen is causing the problem as it sticks worse through each color.
I can flash between each color and the prints come out very nice, but I don't want to be flashing between every color as I have a few 4-6 color jobs coming through and that would kill my efficiency.
I've been using Texsource inks as they are only about 10 minutes from me and I can get anything I need first thing in the morning on the way in.
Garment - 100%
Off-Contact - 3/16"
Underbase - Tex Cotton White (not reduced) - 80dur squeegee - 160 mesh
Other Colors - Tex GEN Series - 70dur squeegee - 305 mesh
Texsource has a Fine Wet on Wet Base as well as a Halftone Base. Would using either one of these help my situation?
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I have never used those ink before so I will tell you what you can check for without the ink.
make sure the white base is cooled down before the next color goes on top
make sure your under base is fully gelled before printing the next color.
I will notice that the ink when flash will go from wet to tacky to gelled. make sure it is past the tacky part but not cured
those are some issue you may want to consider if you have not already
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Only time I remember that happening is when I 'did' flash between.
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Make sure the pallet temp is not too hot where it's curing the inks from the inside of the shirt out. That will cause inks to get tacky and start building on screens next in the order. Do you have a picture of the artwork you can post?
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I never thought about pallet temp. But now that I think about it, they do somewhat stick if I flash between each color. The prints still come out perfect if I run them this way, but it just never dawned on me.
Have checked the flash time multiple times on this one. Getting them just past tacky, but not fully cured.
I run aluminum pallets without any rubber material on them, but I have 6 stations so it has time to cool. I leave a station between me and the flash so that I don't get cooked. but that still leaves 3 stations before it gets back to me. Would it help the heat soak in the pallet if I were to get the rubber material on them?
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try this:
lower your off contact a little, move the 15N screen to the front, speed up the stroke and flash longer (maybe even twice as long). Then grab 20 blanks/scrap shirts and run them through. By the time you get to the last one, it should start working. Let us know if you if it does not.
Also call TEX and confirm the inks are WOW compatible. Many inks out there just can't do it. You will want something that is designed specifically for WOW printing. They might also have an additive to make it work better, but in the end you should use the WOW inks as it makes a huge difference.
pierre
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Also call TEX and confirm the inks are WOW compatible. Many inks out there just can't do it. You will want something that is designed specifically for WOW printing. They might also have an additive to make it work better, but in the end you should use the WOW inks as it makes a huge difference.
This is the reason I chose their GEN series inks. Reasonable price, and designed for WOW printing.
Going to try to do a little R&D before heading out of here for the day.
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I just popped off a few on white without the underbase. They printed amazing. The 15n screen does attempt to stick, so I stuck it at the beginning of the print order and I couldn't be happier with the print... on white that is... without the underbase.
As I said earlier, my platens are aluminum and covered in platen tape, but do not have any platen rubber. I never paid much attention before, but they retain a LOT of heat. I hit my underbase, flashed, and let it sit for a minute or so with a fan blowing on it and it was still hot to the touch. Top colors still stick once printed on the underbase. Underbase is flashed until dry to the touch, just past tacky. It sticks so bad that the entire image area of the last screen doesn't come up until I lift it.
Hard to see in the picture, but you can tell that the ink is pulling up on the back side of the screen.
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Sounds like the Tex Cotton White isn't a good white for an underbase, at least unmodified.
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Any suggestions for an underbase white ink? I'd be willing to try a few different inks to find one that I like.
I'm printing this design on 100%, but I'm split between 100% and 50/50 in my typical jobs.
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What kind of press?
Pierre
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Is the underbase a solid layer of white or is it halftoned?
The underbase does not have to be solid layer. Just solid enough to provide sufficient opacity.
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What kind of press?
6 color, 6 station, Brown Master Printer
Is the underbase a solid layer of white or is it halftoned?
Solid
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If you are on a manual press, do yourself a favor and get some Meteor White by Galaxy Ink. Spoiled is the word I use to describe my printer now.
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I hate to be the bad guy here but if your printing on a manual you got to rotate anyway...you might find flashing each color might be best and I don't think it will kill your speed that much if any. Once you get moving your pallets want be that hot, you would be very surprise at how printers flash every color, they might not admit it but it happens.
darryl
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I hate to be the bad guy here but if your printing on a manual you got to rotate anyway...you might find flashing each color might be best and I don't think it will kill your speed that much if any. Once you get moving your pallets want be that hot, you would be very surprise at how printers flash every color, they might not admit it but it happens.
darryl
1 Flash/2 Rotations OR 4 Flashes/5 Rotations
I may have only been printing in house for 4 months, but I can surely say that flashing once and printing WOW will be twice as efficient as flashing between every color. I'll ship the job out the door flashing between every color, but I would like to learn to do the job more efficiently.
Time = Money
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How are your rotations changing so much based on flashing vs no flashing? I rotate my platens one full rotation before I rotate my screens regardless of the print. Even if you are printing top colors wet on wet, you will be flashing your base, so the only way you would change rotations would be not rotating the platens after the fourth print for each color, which would save you at most a bit over a single rotation of the platens in total during a 5 color job with a base (1/4 rotation per top color for 1 1/4 rotations of the platens after the base is flashed). That may seem substantially more efficient, but you are still rotating your screens during that fourth shirt, and you can rotate both at the same time in essentially the same amount of time, meaning you aren't actually saving any time by doing it that way. If you are rotating your platens only twice in total (once during the flash, and 1/4 per shirt then printing all top colors one shirt at a time), it means you are rotating screens a ton more times than necessary which is far less efficient than doing all of a single color at a time on all shirts, then moving to the next color. I have done time tests on this, and in every scenario it is much faster to rotate shirts printing a single color at a time than it is to print multiple colors per shirt then rotate shirts. This makes the flash vs no flash point moot.
Moving the platens more is faster/better than moving the screens more for a lot of reasons. First, you are putting sideways pressure on your screens fewer times during a run, which lowers the probability of moving one out of registration. Second, it allows you to use one hand to hold the screen slightly up and one to turn the platens in a method that minimizes the up and down motion of your screen and speeds up the time between print strokes. Third, you are trying to get the screens lined up to the registration gate for every print of every color instead of just the first print of each, which inevitably will cumulatively take longer than having those screens already in place vertically. Fourth, the rhythm of your process doesn't change depending on the number of colors or type of ink etc. which means you simply get better at it in the long term due to muscle memory and the ability to tweak the fine movements of the process. This last one has been huge for me, and I have really seen it come into play recently as my jobs have gotten larger and more complex.
I only do wet on wet when it aids in the blending of the colors for art reasons, or when doing waterbased prints where I simply don't even have the flash turned on.
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How are your rotations changing so much based on flashing vs no flashing? I rotate my platens one full rotation before I rotate my screens regardless of the print. Even if you are printing top colors wet on wet, you will be flashing your base, so the only way you would change rotations would be not rotating the platens after the fourth print for each color, which would save you at most a bit over a single rotation of the platens in total during a 5 color job with a base (1/4 rotation per top color for 1 1/4 rotations of the platens after the base is flashed). That may seem substantially more efficient, but you are still rotating your screens during that fourth shirt, and you can rotate both at the same time in essentially the same amount of time, meaning you aren't actually saving any time by doing it that way. If you are rotating your platens only twice in total (once during the flash, and 1/4 per shirt then printing all top colors one shirt at a time), it means you are rotating screens a ton more times than necessary which is far less efficient than doing all of a single color at a time on all shirts, then moving to the next color. I have done time tests on this, and in every scenario it is much faster to rotate shirts printing a single color at a time than it is to print multiple colors per shirt then rotate shirts. This makes the flash vs no flash point moot.
Moving the platens more is faster/better than moving the screens more for a lot of reasons. First, you are putting sideways pressure on your screens fewer times during a run, which lowers the probability of moving one out of registration. Second, it allows you to use one hand to hold the screen slightly up and one to turn the platens in a method that minimizes the up and down motion of your screen and speeds up the time between print strokes. Third, you are trying to get the screens lined up to the registration gate for every print of every color instead of just the first print of each, which inevitably will cumulatively take longer than having those screens already in place vertically. Fourth, the rhythm of your process doesn't change depending on the number of colors or type of ink etc. which means you simply get better at it in the long term due to muscle memory and the ability to tweak the fine movements of the process. This last one has been huge for me, and I have really seen it come into play recently as my jobs have gotten larger and more complex.
I only do wet on wet when it aids in the blending of the colors for art reasons, or when doing waterbased prints where I simply don't even have the flash turned on.
I'll second this. You are not adding any extra time if flashing between every color on manual.
Print one color at the time, move the pallets at all time, colors only after you printed all the shirts with a previous color. Print all white underbases, print second color on all, move to the third color, print third on all, move to the fourth color, ....... and so on.
If the colors are WOW compatible, you should not be doing this. If not, still better that struggle with a blurry prints.
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The large open areas you're trying to print WOW aren't doing you any favors, and everyone has already mentioned the most important factors but there are several causes to buildup. The biggest one is the ink itself. I've been told so many times that an ink was WOW compatible, especially the brands that aren't named Rutland, Wilflex, QCM, One Stroke, WM Plastics and a few others, but the inks that are made and then rebadged have proven in my experience to be much less WOW compatible than the major players. Second issue which Danny mentioned is HEAT. It's your enemy in WOW printing. The third is screen tension, the fourth is mesh count, and if you have all those ducks in a row, you're good to go.
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You know how I'd do it! Another reason we hate plastisol.
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Like I said once you get going flashing between every color you'll be just as fast, I've had to do that using my auto...sometimes things just want work right and I have to band-aid it LOL.
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I've already sent this one out band-aided, but I'd like to not have to band-aid it in the future.
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The large open areas you're trying to print WOW aren't doing you any favors, and everyone has already mentioned the most important factors but there are several causes to buildup. The biggest one is the ink itself. I've been told so many times that an ink was WOW compatible, especially the brands that aren't named Rutland, Wilflex, QCM, One Stroke, WM Plastics and a few others, but the inks that are made and then rebadged have proven in my experience to be much less WOW compatible than the major players. Second issue which Danny mentioned is HEAT. It's your enemy in WOW printing. The third is screen tension, the fourth is mesh count, and if you have all those ducks in a row, you're good to go.
I'm starting to think it's a HEAT issue. The print runs perfect on white without any heat on the platen.
1. Should I be halftoning the underbase to help with the heat issue?
2. Will adding the rubber top from action help with the heat soak in the aluminum platen?
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Turn off that flash ;)
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FYI, Tony is saying you should switch to discharge. It is not an option for everybody or every job. . .
I am more inclined to think that you are not flashing enough. How long are you flashing, what's the distance to the flash and what is the platen temp?
pierre
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I am more inclined to think that you are not flashing enough. How long are you flashing, what's the distance to the flash and what is the platen temp?
I run a 15 second flash normally. Tried this one at 15,20,25,30 and longer. Print acts the same every time. 15 gets us just past tacky.
I'll put the temp gun on the platen itself here after a while.
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what mesh count for the top colors?
pierre
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160 base. 305 top colors
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Top coat mesh count is a bit high for vector
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What would be your mesh recommendation?
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Possible that he does not have enough emulsion/stencil EOM on the screen itself, and combined with possible excessive squeegee pressure that he's blowing the ink out of the stencil gasket making it blurry. Just something else to look at. I think without seeing what's going on in person it's a bit hard to say what's going on unfortunately.
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15 seconds to flash??
Isn't that a bit excessive? I flash maybe 4-5 secs, at the most. And that is with flash about 4" of the pallet.
I have an air forced flash, that might make a difference, but I do not think it should be that much
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When I printed on my manual I would flash each color because I didn't have a fancy auto rotating flash. At most I'd flash for about 10 seconds. You try to time the flash for the same amount of time it takes you to print the next pallet. Lower the flash over the garment until it flashes that fast. I have a GEN series purple from texsource and my first impression pulling it out of the bucket is it's REALLY thin, which should be ok for wet on wet. I haven't printed it wet on wet yet as the job didn't need it.
Like Alan said, those large open areas you're trying to lay a top color on really hurt when printing wet on wet. Maybe try a very quick push stroke. Seems like that used to help the blurring on a manual press.
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I'm nowhere experienced as TonyPep, but on a manual with vector art, top colors 160,200,230 mesh count, I found it hard as the devil manually printing through a 305 all day. RacerTee your getting some good advice from some of the top notch in the biz here ( nope not talking about me LOL) your going to pick up on a lot of good stuff, I know I have.
darryl
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I am a manual printer and have run wet on wet fine with normal inks on some jobs, but this job screams for a flash on each color. There is no benefit at all to not simply flashing them all, especially since you will be flashing the base anyway.
Generally speaking, I run 180S or 225S for all bases these days. I do not halftone bases usually, especially when the art has something like yellow like you posted. I run top colors on either 225S or 280 (standard mesh thickness). I pretty much reserve the 225S for colors that need the bump in opacity or colors that are inherently gummy (like a lot of flourescents). I REEEAAAALLLY like 280 mesh for top colors. 300/305 is just too hard to print manually, and doesnt offer much over a 280. Anything under a 225S/230 would make for a thicker than necessary print in my experience. The only time I use those meshes any more are for waterbased when it's all I have laying around unexposed, or when doing one hit dark on light stuff that has minimal detail.
A push stroke will also clean up your prints A LOT when used with a triple duro squeegee.
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I have to agree, this is screamin' for flash between colors....if it's a plastisol base. On a DC base this may go down very smooth printing the top colors wow. Generally speaking though, we don't wow print big spot color fills. By the time you dial it all in and print those 2 dozen or more testers you may as well have revolved it and flashed where you wanted, the job would have been done or near done in the time a wow setup might take, depending on order size of course.
Really though, try the DC UB, you'll get those WOW results from the top plasti colors just like you saw printing on white.
As far as mesh counts go I find it hard to have a consistent reference when printing manually v. auto, you can do so much more on the manual to adjust ink deposit that it can very so much in what those screens are letting down. If we were printing this manually I would be using a 180 or 150 for the UB and then probably 225 or 270 for the top colors, all thin thread S mesh. I like to keep our mesh as open as possible for any job, especially those going on the manual. It's less work for both man and machine and more ink on the garment v. in it when discussing plastisol. You can also print faster with more open mesh.
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Platens staying right at 95deg and the ink cools to 125 in normal rotation. Would you consider this a heat issue Danny?
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is that 195 or 95? one is too hot the other is too low. Your ink needs to hit mid 200's to gel, maybe even high 200's. Ask TEX about the gelling and curing temp of the ink then go 20-30 degrees below it.
pierre
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Those aren't my flash temps. Actual temps of the platen surface. During a production run tonight doing PFP on another job platens were consistently 140 degrees. No issue printing white ink, PFP. Same white ink used in this job.
The back side of the screen isn't sticking to the already printed ink as much as the open area of the mesh is sticking to the ink just printed. Could I not be sheering the ink correctly?
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The back side of the screen isn't sticking to the already printed ink as much as the open area of the mesh is sticking to the ink just printed. Could I not be sheering the ink correctly?
This sounds like peel.
Try a bit more off contact. Or tighter screens. Or some mesh with more open area
Murphy37
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I haven't read all the responses to this thread but it sounds like you're using a very opaque series of ink or they're a bit to thick and might need to be reduced a bit. Pick off and orange peel effect are notorious of trying to print opaque inks WOW or the inks being not viscous enough.
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Decided to revisit this today since I had some downtime. Tried Union Ultrasoft SO White and every screen in the batch is 26n. WOW on white is better than last time, and it doesn't stick as bad when printing on the UB.
I'd like to try a discharge underbase and/or some wet-on-wet base mixed in the top inks. Never done any DC printing. Can anyone shoot me in the right direction there?
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I know someone
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Decided to revisit this today since I had some downtime. Tried Union Ultrasoft SO White and every screen in the batch is 26n. WOW on white is better than last time, and it doesn't stick as bad when printing on the UB.
I'd like to try a discharge underbase and/or some wet-on-wet base mixed in the top inks. Never done any DC printing. Can anyone shoot me in the right direction there?
hmmm, Ultrasoft white? What is that? If going with Union product, try premium bright cotton white or EZ Print White (we used the EZ for many years and it worked great for underbasing).
As far as DC, order a couple of samples and give it a try. Get a white and a color like orange. burn on a 110 without the registration marks and then close all the pinholes or openings with emulsion. Let it dry and leave out in the sun or post expose. Add 6% activator and make sure your screens are flooded while not printing (so the ink does not dry in the openings). Slow down your dryer to a crawl and you should be good to go.
pierre
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I wondered about the Ultrasoft SO white myself. I use the Union Bright Cotton White for underbase.
Lee, I know you've been back at this trying again with a little more success, but did you ever get a halftone underbase or is it still a solid underbase?
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I printed a halftone underbase film, but haven't burned it. Tried some WOW base, first mixed in at 15%, then at 50% just to exaggerate, nothing. Same problems.
Got my hands on some Union Ultrasoft inks for the top colors. Much better, but still sticking slightly. The buildup isn't as bad, and it may be doable after a few strike offs.
I can say for sure it is not a heat issue. Print/flashed an underbase right before packing up to come home for the night. Let it sit after I shut everything down and prepared to head home. Same problem as before.
Since trying out the Ultrasoft ink for top colors we have less stick issue if I get the off contact up above 1/4". Every screen is 26n on the nose. May need to dial the press in better. Will go over that sometime tomorrow.
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I'd be really interested to find out if any change with the halftone underbase.
Let us know.
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My concern with the halftone underbase is losing opacity of the top colors. I have to PFP the base to get the top color opacity that I would like to see.