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screen printing => Screen Making => Topic started by: alan802 on June 29, 2012, 11:30:14 AM
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(http://i485.photobucket.com/albums/rr211/alan802/SRI%20Pics/IMG_4184.jpg)
It's an 83, but I don't know what thread diameter. It's a shurloc EZ panel that's not quite 2 years old. I would guess this screen has not been used more than 6-8 times over the past 18 months and it's obviously done with it's useful life. Kind of dissapointing that something like this happened with a screen that's hardly been used. If my guys aren't busting them by being careless, something like this is happening. I am at my wits end with all these screens. I stretch them up, and at the same rate, they bust, I don't know what else to do. I'm thinking about going to all newman roller mesh. I have about 15 of them stretched up with all 205N, and not one of them has developed a hole or busted because of misuse.
I did buy some 102N panels from Ryonet that all 4 busted when I tried to retension back to 45 newtons. Strange thing about those panels is the 102N is supposed to be yellow in color, and mine were white. They stretched fine initially but during the first run of retensioning they all couldn't handle the strain of going back up to 45 newtons and busted as they were sitting in the corner waiting to be degreased and put back into production.
I've had some pretty bad luck lately with the panels, the bolt mesh is holding up ok, even the S thread screens but the screens that are a year or two old are dropping like flies. I'm afraid I'm going to blow up when I see a screen being mishandled and it's going to cause some problems. My guys just don't seem to "get it" and me being nice and calm about the problem is obviously not working. I screamed and threw things one time and that didn't work very well either, I don't know if I have the patience to deal with this much longer. I'm getting some relief by telling y'all about it so just bare with me while I vent.
All I know is when I was out there handling most of the screens we didn't have this issue. The screens were newer though, and we still had a large amount of statics in production so I know those don't bust as easy as a 150/48 at 30 newtons, but if the screen will last one run through production with no problems, it should make it 100 times through. I think it's a perfect storm of product failure, mishandling and bad damn luck. I've even tried backing off the tension levels and that hasn't worked yet.
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To me, it looks like a screen stretched past it's limit, and is self-destructing relatively evenly over the whole open area.
Have you contacted Shurloc?
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Haven't contacted them, most of the panels that are busting or failing have been in production for well over a year. Most of them look to be our fault, but there are several that have done weird things like this and I lean to it being product failure rather than us. This one has done it's job a few times and I didn't see any signs of failure but obviously this one has a problem and I am pretty sure it's not because of abuse. We can't overstretch the EZ panels.
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That is a little different, but I've seen it before. Usually, it's from rough handling like overly aggressive scrubbing. I used to see it with multifilament meshes back in the day, when the pressure washer was too close, but this is a monofilament...
Steve
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Although I can't be sure, and it looks a little different from what I've seen, my guess is that the direction the rips are going has been overtensioned and the threads are breaking.
I've never had one look that bad, but I've had similar looking screens before. If you only retension the 'weft' direction (since that's the direction that loses tension from printing) this will happen...
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That is a little different, but I've seen it before. Usually, it's from rough handling like overly aggressive scrubbing. I used to see it with multifilament meshes back in the day, when the pressure washer was too close, but this is a monofilament...
Steve
I've never seen that spread out so evenly
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I've seen it only on super tight low mesh screens. No idea how it happens, it was like that when I got here!
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we had something similar looking but much, much smaller in size on static frames with 83LX mesh. It was caused by the pressure washer being to close to the mesh in our case.
pierre
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Hey Alan,
I think you have two issues here from what you said:
- Not enough mesh safe spaces and/or improper handling.
- Imbalanced stress/strain and/or too high tension on some of your screens.
It's probably a combo deal causing all this. I say this because you mentioned panels popping. If you don't take a panel to very near the exact tension they intended for it when produced it's going to have poor properties. A hand loaded screen gives you the control to adjust to the tension you're going for and know that intuitively. I read some Joe Clark lit that illustrated a test where you take the meter, start at the corner and place it diagonally, at a 45, to the sides, parallel to the roller frame corner. Drag the meter diagonally across the screen to the other corner. Your tension should remain stable across the journey. If it doesn't, you're losing some healthy print characteristics and if it varies wildly, your screen is weakened.
Also- watch that tension on the S mesh. When they say 24n/cm max, they mean it. You can go higher but will absolutely experience premature failure if you do. Your 150/48 shouldn't be at 30, it's a little too high.
You need to get your guys on track with the handling and that might take some re-working of the path of travel for the screens. I agree, I almost never pop screens when I'm the one doing all the handling. But remember, we're telling staff to hustle them out but at the same time wagging a finger and telling them to handle everything delicately. Our shops need to be layed out to allow both of these things- speed and gentle handling and, most importantly, inspection. Get them setup so that every screen comes off press, goes through reclaim and is then checked for tension and inspected on the light table before degreasing and coating, no exceptions. It's going to up your labor slightly but drastically drop the crap screens that are making it to press. Giving your crew this inspection step lets them see their own mistakes. Instead of throwing a fit on 'em, give them some kind of reward for catching busted mesh while explaining that the goal is to decrease that issue.
The quickest fix for you might be going to roller mesh on roller frames that you load, no panels. Those were indeed the most durable screens I've ever had in the shop- tough as nails and capable of holding tensions beyond your wildest dreams if you really want them to but that would just bring you back to square one with popped screens so maybe try 40 n/cm as a baseline on the roller mesh.
You probably know all this stuff but figured I'd suggest incase you didn't.
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Let me guess? You made a really thick stencil and put it in the sun to dry? The damage looks to only be in the stencil area. That would make me think that the emulsion it self is at fault for the damage.
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Let me guess? You made a really thick stencil and put it in the sun to dry? The damage looks to only be in the stencil area. That would make me think that the emulsion it self is at fault for the damage.
How? It appears the areas that are not damaged are being held together by that emulsion!
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Let me guess? You made a really thick stencil and put it in the sun to dry? The damage looks to only be in the stencil area. That would make me think that the emulsion it self is at fault for the damage.
How? It appears the areas that are not damaged are being held together by that emulsion!
Its really a guess. With normal stencil thicknesses you don't see any manipulation of the mess but with thicker stencils you can feel a little pull from the emulsion on the mesh after dry. If the drying process took place at over 150 to 200 degrees like in the sun. I would guess that the expanding and then contracting would do this to the mess. Remember Alan likes to use really thick stencils so this is not a normal situation.
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Keep in mind some of the meshes in the 80s tpi range can have quite thin threads and they tend to walk around along the warp or weft I've found. I've received panels of very high open area low counts that already have these aberrations and unfortunately are pretty hard to correct before stretching. There's just a lot less 'structure' to the mesh when the tpi is low and/or the threads thin.
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Thanks for all the replies guys. One thing I always noticed with this particular screen is the size of the threads. It seems as if they are on the super thin side, around 60-70 microns if I had to guess. I'll look at them under the loupe when I have time and try to compare it to others and get the thread diameter. Don't get me wrong, I love the panels and the company and overall products they sell, but the first round of EZ panels I bought, with this mesh being in that, I had no idea what mesh count I was getting. I ordered 86's, 110's, 140's, 156's, 195, 230's and 305's in those first 3 orders, and there were panels of the same mesh count that were definitely not the same thread diameter and sometimes even the color would be off in the dye of the mesh. Granted, when I placed my orders back then, I wasn't very specific, I ordered 110's and 156's, not 110/81 or 156/64 like I would now, so whatever they sent me was probably exactly what I told them with the first number and I never specified thread diameter or even mesh manufacturer. Now I'm a very picky little bitch about it and I'd be able to catch it if something wasn't what I wanted.
This one hasn't seen any sun and is a fairly thick stencil, around 70 microns. I used this screen to do a one hit tan on military green Beefy T, and it worked perfectly for this so I really hated to see this screen die like it did.
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Ok let me take another shot at this one. I didn't know you printed with it. If the screen was fine before printing then the only answer is that you didn't have enough emulsion on the print side of the screen to protect the mesh while printing. This could be caused from a few things. The emulsion did not dry fast enough and moved to the bottom of the screen. (not likely guessing at how hot your shop is) Or the emulsion broke down on the print side during printing. This would allow the squeegee to pull the threads. (soft large threads of a low mesh screen) If you look at the screen all the mesh is pushed in the same direction. So my final answer is your emulsion was breaking down or not enough emulsion was on your print side to protect the mesh from the squeegee.
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A little more info about this screen might help shed some light on the subject. This was a screen that we would use, de-ink, de-tape, clean up and catalog until they ordered again. They ordered a few times a month. I developed this stencil about a month ago with Ulano Orange and we did the job I'm referring to 2 times so it's been cleaned (not reclaimed) twice and then goes into the dark room until it's time to use it. My printer pulled it yesterday to print the job and that's what he found. He said it was fine when he used it last, my newest screen tech showed me how he cleaned it and there wasn't anything out of the ordinary about his procedure, he did it just like I showed him.
Thickness gauge shows the screen is 100 microns thick, with emulsion it's 172 microns thick, the thread looks very thin, almost identical to a 110/71 S thread I have. I remember when I wrote the mesh count on the outside of the screen, it was stamped 83, but I can't find an 83 on any manufacturer's spec sheet that has thin threads. Sefar has an 83/120, but I don't think there is any way these threads are 120 microns.
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Perhaps it was the weight of all that emulsion........... ;D
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Also- watch that tension on the S mesh. When they say 24n/cm max, they mean it. You can go higher but will absolutely experience premature failure if you do. Your 150/48 shouldn't be at 30, it's a little too high.
I have been having excessive breakage with my Shurlocks as well. We have had way to many separate right in along the locking strip on the short side of the frame. These S panels are only a couple months, 150 and 225 mesh. Often they will pop after being degreased and in the drying rack, nothing like coming in the next morning and having 2 or 3 frames with broken mesh. All failures have been on the hsort side which I find peculiar. Shurelocks spec is 29n on the 225 S mesh which is the max specified by Murakami. I also have noticed a lot of small holes developing in the image areas of the panel. I like Alan feel a screen should last a very long time and am getting frustrated wit the Shurelock - S mesh product.
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Also- watch that tension on the S mesh. When they say 24n/cm max, they mean it. You can go higher but will absolutely experience premature failure if you do. Your 150/48 shouldn't be at 30, it's a little too high.
I have been having excessive breakage with my Shurlocks as well. We have had way to many separate right in along the locking strip on the short side of the frame. These S panels are only a couple months, 150 and 225 mesh. Often they will pop after being degreased and in the drying rack, nothing like coming in the next morning and having 2 or 3 frames with broken mesh. All failures have been on the hsort side which I find peculiar. Shurelocks spec is 29n on the 225 S mesh which is the max specified by Murakami. I also have noticed a lot of small holes developing in the image areas of the panel. I like Alan feel a screen should last a very long time and am getting frustrated wit the Shurelock - S mesh product.
I have seen that picture posted above in our shop. Not fun times. And yeah, when they say 24n or 29n they mean it. I did several well over to bring it up to our non s mesh and man they did great on the press (great prints, fast press time) but after just a couple of weeks - pop, pop, pop. We will be moving away from the product soon
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Did you check the ink for debris? Had a guy here who took ink he spilled off the floor and back into a bucket (luckily only a quart) and we ended up having to cure the rest of it and throw it out--although we didn't have this happen, it was all scratches and rips parallel to the squeegee stroke...
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Alan, I'm pretty certain it's an 83-70. Sent you a PM
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That's really weird breakup.
I'm kinda the same way, in that, me handling the screens, no problem.
Others..well.
Seeing as I'm the one fixing the stuff, I'd say I got a right to bitch.
I'll admit, I didn't read all the replies, just kida jumpin in here.
I use roller retens with bulk mesh, have been forever aside from our smaller, square static jobbers. ( ahem.. )
When retentioning them and bringing them up to 'proper work hardened status' after a job or two, I rarely go over 28n.
Many may balk at this, but they stay consistent around there for many, many consecutive beatings , and rarely get funky.
This is due to my own limitations/quirks/whatever, but it works, and it took awhile to get there.
Find your 'zone' where the new kids can't destroy everything but it works properly and consistently..and run with it?
Often times, many suggest 'perfect' variables, but in the real world, you must adjust accordingly.
It's just a gauge to be used as a reference. Kinda like zeroing in a scale..calibration stuff, but not set in stone.
Don't let anyone tell you otherwise.
Cheers.
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Kinda looks like a mouse head I have no idea what caused it though
Sent from samsung gem(the worst smart phone ever)