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screen printing => General Screen Printing => Topic started by: mimosatexas on August 08, 2016, 10:56:00 AM
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This might fall under the newbie section, so move it if necessary...
I have only recently started getting busy enough where ganging screens made sense due to the volume of jobs enough art of the same ink color at the same time or art that is small enough to mask off and use different ink colors on the same screen. The "issue" I'm having is figuring out how to mask off the first image when switching to the second image. I have tried taping the substrate side, but have run into issues where the ink mixes with the tape adhesive and causes a mess during reclaim. I have tried using paper and extra films and taping those over the image area on the substrate side, but on certain jobs have ended up needing to print over those areas a bit and that causes a lot of ink to go through the screen in those areas, and again a mess during reclaim. I have not cleaned and tapes the squeegee side as that seems like it negates a bit of the benefit of the ganging in the first place (added time and chems). Anyone using a tape that doesnt react with plastisol when taped on the shirt side, or have any other general tips. Really the main issue is when trying to gang images that are borderline and probably too close together. Any help is appreciated. Thanks!
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Are you, by any chance using a tank with an ink degrader/reclaim combo?
I tape the already used image on the shirt side with my usual rubber based adhesive packing tape, and have no issues with reclaiming, but do not combine the two procedures.
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When ever we have done it we just go under with the same tape we block out the screen with and tape out the done image. Ganging seemed to make sense for a while, but testing time in reclaim vs time on press, burning the indipendant screens wins big time. I thought I was saving us time and money, and stopping to tape out, flip, move ink, register, ect isn't really worth the the extra hour or two of weekly reclaiming for the additional screens, at least for us. Funny my wife and I were just talking about it this weekend and going over the recorded numbers. Especially with the GT 3, I set up multiple jobs/ or sides at once, then hop from job to job. If I gang'ed a screen set, that time because a huge waste at the end of the week, then multiply that over a month vs the extra screens, at least for us the ganging stops. But if you are going to do it, for years of me doing, I just used the same 3" tape. Now if you are doing a wb / discharge set up, I wouldn't really think about ganging, that's too much of a chance of a leak through the used image, just my 2cents ;D
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Pallet tape on the print side solves this problem. (if printing manually)
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when we were manual, at first i did that. but then when i got a screen cleaner, it was wayyy faster to just set up the independent screens and go. I was tired of all that messing around, and i was not saving time by no means. I think just setting up and going pays for itself.\
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Another note on ganging screens.
I rarely gang the front and back of the same job, especially multicolor. This is because it pains me to no end to have to go back and clean and reposition the screen(s) for a make-up when I discover a bad shirt when folding and packing.
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Are you, by any chance using a tank with an ink degrader/reclaim combo?
I tape the already used image on the shirt side with my usual rubber based adhesive packing tape, and have no issues with reclaiming, but do not combine the two procedures.
Not sure what you mean about the tank. Not taking off, cleaning ink, and putting back on press. Just flipping the screen around in the same head.
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When ever we have done it we just go under with the same tape we block out the screen with and tape out the done image. Ganging seemed to make sense for a while, but testing time in reclaim vs time on press, burning the indipendant screens wins big time. I thought I was saving us time and money, and stopping to tape out, flip, move ink, register, ect isn't really worth the the extra hour or two of weekly reclaiming for the additional screens, at least for us. Funny my wife and I were just talking about it this weekend and going over the recorded numbers. Especially with the GT 3, I set up multiple jobs/ or sides at once, then hop from job to job. If I gang'ed a screen set, that time because a huge waste at the end of the week, then multiply that over a month vs the extra screens, at least for us the ganging stops. But if you are going to do it, for years of me doing, I just used the same 3" tape. Now if you are doing a wb / discharge set up, I wouldn't really think about ganging, that's too much of a chance of a leak through the used image, just my 2cents ;D
Not ganging waterbased as I found it had issues like you mentioned. Typically not ganging anything multicolored either at this point unless it is small art like a left chest. Usually these are White or black ink 1 color jobs, often a front and back of the same job. For me it is definitely saving time, even with the issue I am having of the ink-adhesive goo, but would love to figure out how to avoid the goo.
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Pallet tape on the print side solves this problem. (if printing manually)
Haven't tried pallet tape yet, but I will.
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Are you, by any chance using a tank with an ink degrader/reclaim combo?
I tape the already used image on the shirt side with my usual rubber based adhesive packing tape, and have no issues with reclaiming, but do not combine the two procedures.
Not sure what you mean about the tank. Not taking off, cleaning ink, and putting back on press. Just flipping the screen around in the same head.
You stated that you have a problem reclaiming the area that was taped due to reaction with your ink.
I merely wondered if, in your cleaning and reclaim procedure, you combine the two actions with one of the combo products, or if you use two separate chemicals.
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Ah, gotcha. I do use a combo, but the reclaim chemicals aren't part of the problem as the ink-adhesive goo is on the screen prior to reclaim. I have tried both the supra and using 701 by itself, and both will loosen it enough to be pressure washed off the screen without issue, but instead of truly being broken down. To clarify, I end up with little goo balls on the back of the washout booth, which is what I'm mainly trying to avoid.
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We gang about 80% of our stuff, and maybe because we do it differently we save the equivalent of a part-time employee in labor hours hours per week versus not ganging. For about 3 months last year we stopped doing it so I could get an accurate comparison and on paper it looks like we'd save around 15-20 minutes for every ganged screen but in reality it came out to be...13-15 minutes. On top of the labor savings we average 140-150 screens per week instead of 250 if we didn't gang them up. No doubt my press guy would rather have one screen for each image but the few minutes we spend dealing with two images per screen are worth it HERE. It obviously doesn't work well everywhere, for whatever reasons I don't really know.
We try to put a left chest or other small logo of similar color (those are key so you're not wasting your time cleaning, therefore eliminating the time you're supposed to be saving) with a larger logo. We print the small logos first on most occasions and we use our clear, rubber based 3" tape and put maybe 2 strips of that tape over the opposite image closest to the other image, on the squeegee side. So when we're tearing down a job with another image on the screen we tape up the image just printed on the shirt side (that's why we try to do the smaller image 1st due to having to tape up larger images then de-taping them for reclaim). And the few strips of tape on the squeegee side when we're taping them up before they go to the press added to the just-mentioned taping does add a minute or two, maximum, to the process at the press during setup/teardown. Then during the reclaim process there is a few seconds added to pulling that tape off the shirt side of the 1st image printed on that screen, but it's seconds and not minutes. At some point, if we ever get so efficient that we could make so much more money with those few minutes versus saving them by our pre/post press actions then we might change. But at this point, I'll take the 15 minutes labor saved total versus the minute or two per job that ganging adds on the other end.
That's just how we do it and the reasoning behind it. Shops that don't bother with it have their reasons I hope, and most of the members here know their shops way better than I do and should have at least done the comparison on paper at a minimum or like us, done a real world comparison. For anyone who doesn't know if it would save them time or not I would highly recommend trying it, and doing it the most efficient way possible and see if it's something that would benefit your production loop.
Pics of a few screens, before and during:
This first screen really doesn't need the tape on the squeegee side because the sq/fb won't go down and contaminate the stencil, most likely, but usually the guys will put it on there if it's possible to touch.
(http://i485.photobucket.com/albums/rr211/alan802/IMG_20160808_130922_zpsti02ejnd.jpg) (http://s485.photobucket.com/user/alan802/media/IMG_20160808_130922_zpsti02ejnd.jpg.html)
These were ganged even though they aren't part of the same job but after we printed the 1st the screen goes back to an area where screens are waiting for press. It could add some confusion if you've got a crew that can't keep their heads right but we've never really had a problem with ganging completely different jobs. We just try to keep the colors the same or very close so we don't have to do any color changes. I hate color changes and we only do them when we have to.
(http://i485.photobucket.com/albums/rr211/alan802/SRI%20Pics/IMG_20160808_130644_zpso4tcsza2.jpg) (http://s485.photobucket.com/user/alan802/media/SRI%20Pics/IMG_20160808_130644_zpso4tcsza2.jpg.html)
This is the other side of the screen shown above with the image taped up.
(http://i485.photobucket.com/albums/rr211/alan802/SRI%20Pics/IMG_20160808_130719_zps1d87xqjn.jpg) (http://s485.photobucket.com/user/alan802/media/SRI%20Pics/IMG_20160808_130719_zps1d87xqjn.jpg.html)
(http://i485.photobucket.com/albums/rr211/alan802/SRI%20Pics/20160808_130509_zpsfugaa6lf.jpg) (http://s485.photobucket.com/user/alan802/media/SRI%20Pics/20160808_130509_zpsfugaa6lf.jpg.html)
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third image: no adhesive-plastisol goo or yall just deal with it? otherwise you're doing exactly what I'm doing when it comes to trying to gand left chests or short art with longer art when possible and taping shirt side of the first after printing and squeegee side of the second when printing the first.
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We have a stack of the trimmed off parts of carrier sheets that we lay over the image and then tape. Keeps all the crud out of the ganged image. You can use anything here really.
We do also gang wb/dc screens but you need enough room and good stroke control on the auto.
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third image: no adhesive-plastisol goo or yall just deal with it? otherwise you're doing exactly what I'm doing when it comes to trying to gand left chests or short art with longer art when possible and taping shirt side of the first after printing and squeegee side of the second when printing the first.
The tape comes off clean (relatively meaning no leftover adhesive or goop) but we don't really have the tape contacting the ink directly, it is on the shirt side after a print run. What tape are you using? We're using the 3" stuff from Uline.
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third image: no adhesive-plastisol goo or yall just deal with it? otherwise you're doing exactly what I'm doing when it comes to trying to gand left chests or short art with longer art when possible and taping shirt side of the first after printing and squeegee side of the second when printing the first.
Using rubber based adhesive tapes I've had the same experiences as Alan and you--if the ink doesn't hit the open area that's taped off, not a pain in reclaim. If the squeegee (or auto flood) goes over it and fills it, it starts that nasty reaction.
If I'm ganging screens that get close together, I clean the screen so I can tape off the printed side on the inside of the screen.
Tried more than a couple different brands and types of tapes that were claimed to not make such a residue when the adhesive hits the inks and sits there for a few hours, but I found none that pulled clean.
Pretty sure that brown tape you wet with a sponge would work, but I can't imagine it'd save time.
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Do you guys use squeegee bars?
We are a manual shop and we gang every screen we can. We use 20x24 frames and typically gang a small design on one side with a medium size design on the other.
We almost always use squeegee bars on these screens, this way we keep ink and contact totally away from the other side. (it's also nice to keep the squeegee close to the design this way). When we flip the screen around after printing one side, we cover up the screen on the shirt side with any random sheet of heavy paper (junk mail flyers work great) we just tape the paper up on the 4 corners. The paper is really there just for precaution since the squeegee bar keeps away all the contact with that area. No tape residue or junk gets caught in the screen this way... For us
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We use these as squeegee bars for our manual.
http://www.lowes.com/pd/IRWIN-QUICK-GRIP-Clamp/50160691 (http://www.lowes.com/pd/IRWIN-QUICK-GRIP-Clamp/50160691)
There are cheaper ones out there, but the ones from Harbor Freight won't clamp tight enough to hold more than a small squeegee blade. The Dewalt ones at Zoro look good and cheap. We use the clamps for all kinds of things, like holding paper towel rolls around the press and as mentioned above to hold squeegees.
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exact same ones I use Alan. Have a set of 6 of the longer version. Have a bunch of the shorter ones too, but i use those for wood working projects now since getting the longer ones. I didn't even thing of using it as a paper towel holder, but that is an excellent idea.
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I have been doing almost the exact thing alan is doing. Usually just left chest images on either end. Sometimes it is a nice horizontal back of front that lends itself to being ganged.
The kicker for me here was to burn both ends of the screen at the same time. I used to block off one end while exposing the other...but figured out how to get multi colored images to keep in register on both ends.
We don't usually use multiple strips of tape to mask the second half while on press. I tend to use films from jobs that are a one time thing or dated events. Then just one strip of tape and i can have the entire second half of the screen covered. This helps for when the ink colors are not the same. Then when doing the second half I tape the bottom as alan does and if the colors are different I use another old film and strip of tape to mask the inky half.
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We have always ganged up screens, going back to the '70's. Why wouldn't you? And yes, tape on the squeegee side keeps ink from softening the tape adhesive, and is a no brainer as far as cleaning goes.
Steve
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We gang most of the time but we try not to gang the same job if it is front and back, so we can setup both sides at the same time. This is one of the main reasons we went to a 10 color auto. It is really nice to have a 2 color front 4 color back and a couple of 1 color jobs all setup at once. That is where we have found a lot of our efficiency. When ever we gang up a screen and the images are close enough that the ink will touch open area of previous run we always clean the screen and cover the finished image with red water soluble block out fluid. Still requires tape on shirt side to ensure no breakouts but it makes reclamation much easier, no nasty tape residue, and no chance that tape if used on ink side to block off will be picked up. If we have a 2 left chest prints and we are sure squeegee or floodbar will not touch the open area we just tape off from the back shirt side.
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We use a piece of cut lumber for our squeegee bars. It's 3/4x3/4 ply. We use cheap spring clamps to clamp them to the frames, one on each end. Works great and CHEAP.
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A little late, but another option to avoid ink-meets-tape goo is to trim a piece of used pellon/test square to fit the area, and run the tape across that. Make sure tape covers the entire image area to avoid any possibility of bleed-through. (Which is most likely if you have to rest your squeegee in the "used" image area.) I've found that to be a quick, easy to clean solution for print/flip/print gangs.
And squeegee bars are great. I discovered them by accident and wondered why no one ever told me about them.