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screen printing => Screen Making => Topic started by: alan802 on September 26, 2014, 10:04:03 AM
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Of those watching this thread, who gangs up images on screens? We have 2 images on most every screen we expose but it seems like it's not quite as popular a method as I thought. We'll never change that technique but I'd like to hear comments on why it's not done or why others like to do it.
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We just did 3 left chest AND a full back on one screen yesterday... Running the job today, I'll snap a pic.
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Most of my designs are 10x10 or 12x12 or smaller. So yeah, gang them. Seems such a waste when only doing one!
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Of those watching this thread, who gangs up images on screens? We have 2 images on most every screen we expose but it seems like it's not quite as popular a method as I thought. We'll never change that technique but I'd like to hear comments on why it's not done or why others like to do it.
when we were doing film we would gang as much as we could. With the I-Image, we dont gang more than 2. We also don't gang images on long runs, or discharge runs longer than 60pcs.
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Almost every shirt back we do is 15x17 inches, so no ganging those. Fronts are so all over the place many are center chest, some are vertical, left chest is less common here. When we can we do it of course, but its always logistically hard to at times remember to stick a left chest from Tuesday with one from Friday at times.
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We gang screens all day long.(film) I feel like I'm wasting screens when I can't, but sometimes it just can't happen.
Murphy37
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We just moved to auto sized frames so when my guy ganged his first job (and for a contract customer), it clicked and he proclaimed, "I just doubled our money on screen charges!" lol
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our processes are setup to where we don't have to gang. I can and do, but it adds extra time on press with taping and whatnot so we just don't do it.
I find it's quicker to pull a screen and put in a fresh clean one.
i'm not trying to save a screen or save room, i'm saving time on press so my guys have maximum use of the minutes in a day to be productive.
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our processes are setup to where we don't have to gang. I can and do, but it adds extra time on press with taping and whatnot so we just don't do it.
I find it's quicker to pull a screen and put in a fresh clean one.
i'm not trying to save a screen or save room, i'm saving time on press so my guys have maximum use of the minutes in a day to be productive.
This is where we are headed as well. It's tough to force yourself to leave all that usable real estate but in the end it's faster.
Every time I see them wiping ink, de-taping, etc. it's a reminder that it takes 5 minutes of non-press time to clean a screen.
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I agree with John. We don't do it often at all, but if an order calls for a color change, it's a new screen for us. Faster to swap out than to clean, dry, re-tape. But that for me, not for everyone.
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But to put an additional screen into the rotation it's 20 minutes for the average shop. I'm sure there are shops that can do everything a screen needs in 15 minutes but less than that and I'd have to see it in person. And there are shops that probably can't do a screen in less than 25 minutes. A new screen has to be reclaimed, coated, taped, setup, torn down, de-taped, etc. and I'd say on the worst case scenario we'd spend 7-10 minutes dealing with a ganged image and on average it's probably half of that. I'm not trying to change anyone's mind, just giving the logic I use to decide how to do it. I know the labor is spread around so that it may not seem like 20 minutes but that's what I get when putting times to every process.
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Maybe I'm not looking at this through the right glasses, that's why I asked the question.
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But to put an additional screen into the rotation it's 20 minutes for the average shop. I'm sure there are shops that can do everything a screen needs in 15 minutes but less than that and I'd have to see it in person. And there are shops that probably can't do a screen in less than 25 minutes. A new screen has to be reclaimed, coated, taped, setup, torn down, de-taped, etc. and I'd say on the worst case scenario we'd spend 7-10 minutes dealing with a ganged image and on average it's probably half of that. I'm not trying to change anyone's mind, just giving the logic I use to decide how to do it. I know the labor is spread around so that it may not seem like 20 minutes but that's what I get when putting times to every process.
Alan you are right on with the 20 minute number for screen cycle time in an efficient shop. You are also correct that it can be much more but the real question is how fast can you do press changeover? You are not making money unless the press is making noise.
I've said it a million times, most of us are more screen makers than screen printers.
In our workflow ganging screens causes people to ask unnecessary questions and slows things down, therefore 1 screen with 1 image makes the press make more noise which in turn makes more money. Yep we are accepting increased time in the screen loop but the dollars support the decision. The bigger the shop the more this makes sense.
~Kitson
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I'd say it is undoubtedly more efficient to gang on a per screen basis, but honestly I rarely do it either as it seems to interrupt my flow to clean screens or worry about inkwell taping and contamination etc. I am a small shop and I much prefer to do work in chunks rather than in the middle of a random day. Burn screens for the day in the morning or for a few days, print all the jobs, clean and coat all at once.
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But to put an additional screen into the rotation it's 20 minutes for the average shop. I'm sure there are shops that can do everything a screen needs in 15 minutes but less than that and I'd have to see it in person. And there are shops that probably can't do a screen in less than 25 minutes. A new screen has to be reclaimed, coated, taped, setup, torn down, de-taped, etc. and I'd say on the worst case scenario we'd spend 7-10 minutes dealing with a ganged image and on average it's probably half of that. I'm not trying to change anyone's mind, just giving the logic I use to decide how to do it. I know the labor is spread around so that it may not seem like 20 minutes but that's what I get when putting times to every process.
Alan you are right on with the 20 minute number for screen cycle time in an efficient shop. You are also correct that it can be much more but the real question is how fast can you do press changeover? You are not making money unless the press is making noise.
I've said it a million times, most of us are more screen makers than screen printers.
In our workflow ganging screens causes people to ask unnecessary questions and slows things down, therefore 1 screen with 1 image makes the press make more noise which in turn makes more money. Yep we are accepting increased time in the screen loop but the dollars support the decision. The bigger the shop the more this makes sense.
~Kitson
That's why I asked, this is why this forum is what it is...which is great for anyone with an open mind and a willingness to learn. I'll go back and see what the affect is on press downtime and put that into the equation more than looking at it from the narrow standpoint I was. It still might not add up but it's worth a look.
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Maybe I'm not looking at this through the right glasses, that's why I asked the question.
put your money glasses on and think cost per minute.
an 8 hour shift only has 450 minutes to be productive
labor hour in the screen room = $11.00 = $.18 cents per minute
labor hour on press = $250 = $4.16 per minute
to clean a screen on press is both a time and money loss.
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I suppose for us it's just that the press is typically stopped while we're waiting on that screen to be wiped or re-taped
or whatever. And it crosses that dangerous threshold of 5 minutes or so where if we aren't printing the press ops and pullers
and catchers start wandering around and forgetting what it was they were doing before we stopped. Plus like John says,
one employees time costs less than 4 or 5 employees time.
Also, I find not ganging makes organization soooooo much easier.
Do automated screen cleaning machines actually work?
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I gang, but not for the same job.
Back of one job, small front of another, same color = no brainer for me
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Unfortunately I don't have enough screens to even try to not gang images right now. I've got 130 in production and if we got from 30 screens per day to 60...I'm gonna have to hire another person to clean screens so my money glasses are on and there is definitely a lot more to this than what I was looking at, but I'm still not sure there's a clear answer for our situation. I'm going back and forth on this and whenever I think I've got it figured out another number enters the equation and sways it back the other way. If hiring another person keeps the press downtime from 1 hour a day to 15 minutes then there should be enough profit in those shirts coming down to make up the additional payroll, but those numbers change a lot depending on a lot of different factors I don't have a handle on right now.
Great discussion.
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O also, I had a spare 48" metal wire rack sitting in the back of my shop waiting for a purpose (picked it up for $20 at an estate sale a few weeks ago, little rust on the bottom shelf) so I just built one of these drying racks. Took $25 of pvc, some bolts and zip ties I had laying around, and about 30 minutes this morning. Holds 18 screens vertically. Here's a few crappy pics, ignore the clutter and random doors and drywall from my screen room build out :D
Classy looking piece of equipment, you officially get to join the tighta$$ fraternity.
~Kitson
I "appropriated" that fantastic design as well, though mine doesn't look as nice. I placed the whole thing in a big
rubbermaid under the bed container in a vain effort to keep the floor a bit dryer.
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We still gang about 80% of our screens around here even using our dts but the more and more I study this in MY shop I realize we are better off when we do not gang screens. I absolutely hate watching my guys de tape a screen, clean it, put pallet tape over the previous image, etc..... We are pretty efficient at reclaim/processing screens and even more efficient with press setups so the time we lose by ganging screens is not worth it for me. Over the next few weeks I'm going to try and compile some data to support this, but again might only apply to MY shop. I have a feeling the data is going to tell me we need to stop ganging screens
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I've never done time studies or anything but we don't gang anything. Thought about trying to gang same color LC designs. Ganging just seems like a huge pain. Plus I like to have jobs tied up into a nice little package before press. Just grab and go.
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We gang almost every job and there is no way we could cycle the screens to keep up if we didn't. Most of the time they are for the same job and same or similar ink color so without a doubt it is much quicker for us. Two guys on the press spinning a few screens around is much quicker than a reclaim guy and a screen guy essentially remaking those same screens.
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We gang almost every job and there is no way we could cycle the screens to keep up if we didn't. Most of the time they are for the same job and same or similar ink color so without a doubt it is much quicker for us. Two guys on the press spinning a few screens around is much quicker than a reclaim guy and a screen guy essentially remaking those same screens.
Great conversations on the logic of decision making on the production floor. Whenever you ask yourself why you do something, if the answer is "because....we have always done it that way" you almost always have room for improvement.
Andy/Pierre/Dan can you split this 'ganging' conversation into a new thread with a proper heading so everybody can benefit from the discussion.
~Kitson
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We gang almost every job and there is no way we could cycle the screens to keep up if we didn't. Most of the time they are for the same job and same or similar ink color so without a doubt it is much quicker for us. Two guys on the press spinning a few screens around is much quicker than a reclaim guy and a screen guy essentially remaking those same screens.
Great conversations on the logic of decision making on the production floor. Whenever you ask yourself why you do something, if the answer is "because....we have always done it that way" you almost always have room for improvement.
Andy/Pierre/Dan can you split this 'ganging' conversation into a new thread with a proper heading so everybody can benefit from the discussion.
~Kitson
I will say that this current turn in the conversation has me thinking differently. As someone who has always ganged screens, I'm having a d-uh moment...
Steve
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I'd say we gang maybe 40% of the time. Usually only left crests or prints less than 6" tall. Our screens are 25*36's and about half are double pinned for ganging. But by only ganging the smaller designs on our size screens, we actually don't even tape off the old design. Just the shirt side gets taped. There is enough clearance that we don't need to fuss with taping inside the screen.
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our processes are setup to where we don't have to gang. I can and do, but it adds extra time on press with taping and whatnot so we just don't do it.
I find it's quicker to pull a screen and put in a fresh clean one.
i'm not trying to save a screen or save room, i'm saving time on press so my guys have maximum use of the minutes in a day to be productive.
bingo. we gang once in a while with crests but it slows down the entire process. I used to think we saved money by ganging but one day, I stood in the back and watched...I'm not saving a dime. the time it takes to prepare a screen to be used properly -twice- I could have had a new one in place and printing. with all the blocking out with old film and taping and junk, waste of time in my book.
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I think some of the responses are missing a couple things.
If there is no ink change the ganging up is pretty awesome and no time is really lost. Throwing 2 pieces over a left chest design to do the small back design right after is obviously worth doing...
The size of the shop and how busy they are will also affect this greatly. A 1 person shop should obviously gang up even more.
We just gang up same ink color (typically same job) and that 'additional' setup is very minimal. 20 seconds a screen maybe. We don't remove screens, ink, use screen or press wash and return to press...that wouldn't be worth it for us.
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I think some of the responses are missing a couple things.
If there is no ink change the ganging up is pretty awesome and no time is really lost. Throwing 2 pieces over a left chest design to do the small back design right after is obviously worth doing...
The size of the shop and how busy they are will also affect this greatly. A 1 person shop should obviously gang up even more.
We just gang up same ink color (typically same job) and that 'additional' setup is very minimal. 20 seconds a screen maybe. We don't remove screens, ink, use screen or press wash and return to press...that wouldn't be worth it for us.
+ One.
If I'm ganging it's same color. No way I would gang if I had to do a color change. And I'm a one person manual shop. And I'm sure this will get some raised eyebrows, but I don't even tape my screens most of the time.
I can see the argument either way though. If I had someone else making my screens I'd be more inclined to not gang, but when it's just me, the less screens I use the MORE I can keep the press spinning.
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We try to gang same color and so that there is plenty of room in between the images and it takes about 15-20 seconds to put a couple strips of tape over the second image (not the whole image, just the first few inches usually) on the squeegee side to keep ink from the ganged image if any were to get to it. Then we take the first image off the press, tape up the shirt side which is about 20-30 seconds, pull the tape off the squeegee side over the second image to be printed and put the screen back on press. Maybe others are doing this differently and it's taking up more time? I spent all weekend going over this and I think I'll do a video today of the typical screen changeover so we can analyze it and see what I'm missing.
I've never been one to harp on keeping the press moving at all times but rather keeping quality as high as possible and never missing a deadline. I remember conversations back in the day where people would talk about how they keep the press spinning and shirts on the belt at all times and although that's the goal, we went after it indirectly by making sure we were efficient at everything we did and not wasting time double stroking or using revolver mode. Really taking a look at this over the weekend I have played with both scenarios and walked the processes through my head numerous times and today I'll be back there putting a stop watch to everything involved in ganging images and comparing that to the 20 minutes standard and how much time the press is stopped because of the pulling of tape and taping up the used image.
We don't do color changes often, I typically only do it when we're short on screens and we need every screen in house for something so it's mainly the extra time to tape up a portion of the second image then putting tape on the shirt side of the image already printed, then I'll add in the extra time it takes to pull the extra tape during reclaim. Doing a complete color change for us is under 5 minutes and probably closer to 3 because we have screen opener and rags at every turn of the shop and it's a pretty quick process but I still don't like to do them if we don't have to. Obviously we're not making money if we're not printing shirts but we charge for setups and screens so technically we do make money the more jobs we print in a day. We are only just now getting into maxing out our production capabilities so the press has been spinning a lot more the last few months than average.
I'll spend the next few days breaking this down as accurately as I can and I'll share everything and try my best to show how everything is done here at our shop. I'll be interested to see how the stopwatch compares to what I've done in my head and I'll make sure there are no biases or pride that gets in the way of the final numbers. However this turns out is fine with me, I've always only been about running the most efficient shop possible and if I've been wrong in my thinking then I'll own up to it and change the way we do things.
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Very interested to see what you come up with.
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Ganging screens sometimes is a production killer unless it's small jobs I can toss on the manual press as well. I have a bunch of 18x20 screens from my old Hopkins press dam near new so I decided I would use those for left chest imprints, less emulsion use on those. I hate to use a full 20x28 screen for a left chest, so here is a question if you could buy left chest screens or small imprint screens would you and would that save you production time and emulsion tape etc.
darryl
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We have toyed with the idea of keeping our 18x20 mzx's for left chest and small designs... probably wouldn't be worth it and will likely sell them.
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we try and gang for a couple reasons...mainly I don't feel like nearly doubling our screen inventory. I try not to gang on the same job, but if we do you just dry wipe the screen and flip it and you're set.
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Maybe I'm not looking at this through the right glasses, that's why I asked the question.
put your money glasses on and think cost per minute.
an 8 hour shift only has 450 minutes to be productive
labor hour in the screen room = $11.00 = $.18 cents per minute
labor hour on press = $250 = $4.16 per minute
to clean a screen on press is both a time and money loss.
I can do the simple math here, but I'm wondering how the labor costs are so dramatically different, $11.00 vs. $250.00... I'm missing something I think.
Steve
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Yeah Steve, if it were really that black and white it would be an easy decision. Where I'm at so far this morning is I've got an average of 11 seconds to tape up the second image on the screen so that it doesn't get contaminated with ink and I've got 2 seconds to pull off that tape before using it. I haven't had a chance to time the screen switch-over where we tape up the shirt side of the image we just got through printing. And then I'll look at the differences in reclaim between a 2 imaged screen and a single, along with the time it takes to peel the tape off the shirt side of the first image. Can anyone else think of other things I need to look at with the watch?
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Yeah Steve, if it were really that black and white it would be an easy decision. Where I'm at so far this morning is I've got an average of 11 seconds to tape up the second image on the screen so that it doesn't get contaminated with ink and I've got 2 seconds to pull off that tape before using it. I haven't had a chance to time the screen switch-over where we tape up the shirt side of the image we just got through printing. And then I'll look at the differences in reclaim between a 2 imaged screen and a single, along with the time it takes to peel the tape off the shirt side of the first image. Can anyone else think of other things I need to look at with the watch?
fixing the leaks.
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Leaks?
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when ink goes under your tape / block out and leaks out from the other design...aka "whatthefukisthis?"
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Watch in reclaim too, for us when we tape over an image and any ink gets in the open area it mixes with the adhesive and makes
a nasty mess, even with using pallet tape.
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Homer, what type of tape are you using? Not that it's never happened but rarely does ink work its way under our tape and we use the 2.0 mil rubber based adhesive clear tape. I think Intertape makes the one we've used the most over the years.
I've got some new tape coming in this week (at least it better be here this week or I'm going to be in trouble and so will my tape supplier) so do you want me to send you 50yds or so of the tape we use Homer?
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If it's the same color left chest and half-sized back I gang them 100% of the time. Pull the squeegee/flood, flip the screen, insert flood behind the ink, chopper down, and drag it up to the stopping point for the back print. If it's tshirts I don't tape off the left chest. If it's hoodies with a pocket you definitely need to tape or the pocket will pick up fuzzy ink in the open area of the left chest.
I also gang different orders with the same colors all the time. I try to avoid having to tape off the old design as eb said it gums up the ink. I can see the benefit of only one exposure per screen if you have a crew running and gunning all day and you load the back print and the front print on press at the same time, might save a few minutes which adds up. But most shops have to wait for the fronts to run through the dryer before the stack comes back around to print the backs. That's a solid 2 minutes for flipping a screen or plopping in a new one.
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But most shops have to wait for the fronts to run through the dryer before the stack comes back around to print the backs. That's a solid 2 minutes for flipping a screen or plopping in a new one.
That's actually a really good point I hadn't thought of.
How does everyone organize ganged screens? That's a major issue for us too. When we put a job on the job cart it can be hard
to be like "oh and the black screen for the back is with that other job over there" etc etc.
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But most shops have to wait for the fronts to run through the dryer before the stack comes back around to print the backs. That's a solid 2 minutes for flipping a screen or plopping in a new one.
That's actually a really good point I hadn't thought of.
How does everyone organize ganged screens? That's a major issue for us too. When we put a job on the job cart it can be hard
to be like "oh and the black screen for the back is with that other job over there" etc etc.
I think this is going toward, "it depends..." A really busy shop would have the screens ready to go with the job, just pop them in and print. A smaller, less busy shop has more time, and the change over in concert with the rest of the shirts going down the line works out pretty well. As I mentioned earlier, we've always ganged prints, with our thought being that we hate to waste the emulsion by not having a print on it. But in retrospect listening to the arguments of both sides, the extra production far outweighs cost of the screen. Perhaps it's wisest to gang jobs that don't go together but use the same mesh, this way they get get cleaned in the normal cycle, but come back to the press instead of the screen room.
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My take on this is no ganging if you want/need complete flexibility in scheduling. Becomes a lot more pertinent with multiple machines and/or shops pushed to the brink of their production capacity every day I think.
If total flexibility in scheduling isn't needed then I think ganging is good where appropriate. Same colors is a no brainer. Ganging different jobs on different screens can be ideal as well. 25x36 frames are ideal for this.
Where it sucks for us is when a screen has a problem and needs reshot. That could hold up two jobs for the day, not just one and I'm not keen on that.