Let's Talk Tension

[alan802]

This has always been one of my favorite topics that has been hammered to death on forums since they were started, but we don't have a dedicated thread to that subject here yet, or that I can remember or find, so let's whip the proverbial ass of this topic some more.

I personally think it's one of the most important variables out of the several hundred that we deal with on a daily basis.  I think it's right up there with press calibration, stencil thickness/EOM, print pressure, separations, mesh specifications and a few others that escape my feeble mind at the moment. 

I used static aluminums for several years before we started to use the dozens of newman rollers we had laying around in the dark room collecting dust.  For the first 2 years I printed, I had no idea how tension affected the entire process so we used the statics instead of the newmans because they were easier to handle (how funny is that?).  With that being said, I can surely attest to the greatness of retensionable frames or for the sake of this argument, higher tension versus lower.  We don't necessarily have to get into newman roller versus static alum or wood, we can simply use low, mid, high and extreme tension levels as our arguing terms. 

Our static alums after several years of use were in the range of 10-21 newtons.  When I bought a tension meter I got to see just how bad our screen tension was and at that time I was starting to get into researching tension and it's importance.  I had noticed some time before I got our tension meter that the tighter screens were giving us better white prints.  In the time we used the statics, much like everyone else, we had somehow managed to print some really quality work.  That's not really the argument I want to get into per say, but feel free to throw in that disclaimer if you are one of those shops. 

Once we committed to using newmans and shurloc ez's I went with the more is better approach and I was stretching our screens to the absolute maximum that the manufacturer would recommend and sometimes I would go beyond that.  For example, there was a time when I was getting some of our 156 sefar past 60 newtons.  We were limited with our shurloc ez frames to the good people at shurloc deciding exactly what tension level they were going to be once settled and work hardened.  Within a couple months of running jobs with extreme tension, I noticed that those screens that I had "neglected" somewhat and allowed to get lower in tension were performing great, they were for example 156's in the mid 30's.  It took a lot of work to keep them screens at such a high level so I then decided to lower my tension levels to a more reasonable limit which was in the high 20's up to 48 on say a 102 Newman. 

I don't know what you would consider our shop in the tension argument, I would say we are proponents of high tension screens and not moderate.  We do have plenty of screens that are moderately tensioned, but for the most part, I put the mesh to the highest recommended level set by the manufacturer.  Since we've made the change to high tension, I cannot tell you how many of those weird ass "problems", or gremlins just went away.  There would be those Murphy's Law days in the static days where every damn job we set up was a PITA and screens were always popping on subsequent screens while printing (not popping as in damaging the screen), registration was hard to get perfect, setups were long and frustrating.  The buildup on the backs of screens was sometimes mind boggling and our ink usage was much higher per print than it is today.  Literally most all of the day to day headaches were a thing of the past.  Don't get me wrong, we still struggle sometimes and things will always be going wrong but I know if we use the right screens for a job and do all of the other things the right way, the day will be smooth.

Is there anyone out there that thinks that tension levels in the 12-20 range are great and some of us that "preach" about high tension are off our rockers?  Who out there has used both statics and newman rollers/shurloc ez's and still prefer statics?  If so, how and why?  Did you give the high tension frames a fair chance or did you give up on them too early?  Is there anyone out there that will argue that they can do the exact same quality print with 15 newton screens versus 30 newton ones?  What are y'all's thoughts about all the other supposed benefits of using high tension screens that I mentioned some of earlier?

What are your overall experiences with low, medium and high tension screens.  I welcome any thoughts from those who haven't ever used more than one type of frame as well.  I've used static aluminum, newman rollers, shurloc ez's and panel frames.   

[GraphicDisorder]

I really want to get into Newmans and shurlocs, but budget isn't there for it currently, I need another embroidery machine.  So that's where my extra money is going right now.

Most of our screens are probably in the 15-20 range and we are getting some pretty great results.  But yes I know it could be even better.

[Fresh Baked Printing]

I use only Newman's and only have a couple statics that I use for Shimmers and Crstallina inks.
Newman's are still only as good as the operator. If they're not maintained to tension, then whats the point of paying for them. Does everybody that uses Newsman's have a tension meter?
I hear (and have seen) stories of amazing prints that were done on 10 year old wooden statics.

I just think that nicely a tensioned Newman removes at least one variable when screen printing.

[alan802]

I do agree that people can do some great prints through low tensioned screens. 

Is there anyone out there that has a bunch of newman rollers and statics and choose to print on the statics every day?  If so, sell me the newmans.

[mooseman]

Mesh tension is a lot like sex, well not really but now that I have your attention I think too much value is being placed on screen tension IN ISOLATION.

If you look at the entire screen printing process as a chain and each operation in the process (example, tension, squeegee choice, mesh selection, and so on) as a link in the chain then there is no one link that is more or less important than any other link in the chain if the chain is to work as expected. A bad link will however fail the entire chain.

Screen tension is however (in our experience) a boundary element, I’ll explain in terms of riding a bike up a hill to the top and down the other side. Once you crest the hill well you know it all gets down hill from there and EASY.

Tension is the same kinda thing in as much as we believe the print result improves noticably at the tension crest we believe to be at @  33 to 35 Nm for the printing we do. We have found below this level we experience nunerous ink, registration, coating and other issues that all seem to go away or at least greatly diminish starting at  tension levels of 30Nm and above.

Especially in ink transfer from screen to garment and doubly so on fleece hoodies and the like. We find loose screens (for obvious reasons) push the garment more in front of a PUSHED squeegee. Not so much a problem on a one color hit but if we are PFP and on fleece we get a shadow or an out and out double hit. When changing only the screen to one that is at 30+ Nm we find the frequency and severity of this condition reduces greatly.

Coating, We use mostly 155 @ 40Nm, 195 @ 35Nm and 205 @ 30Nm minimum. We coat to the full shine condition and then  hit the opposite side 2 times. With tensions below the 33Nm area we find we get inconsistent EOM across the width of our 18 inch track.  Above 33Nm we get a far better result in terms of full width thickness of the coating. This is painfully apparent with a fully dry screen and a quick review in the light. We can easily see a difference in thickness across the width of the deposit from center to edge on lower mesh screens.

So for the printing we do we like to see a minimum of 33 Nm on all screens and will stretch any screen every time to every last Nm we think we can get but tension is only one note in the whole song.

mooseman

[alan802]

Awesome post Moose. I do take a slightly different stance on the different variables and their importance but I do understand why you feel that way about them as a chain. I very much agree on them each having a great affect on the next and the entire process. I just think that a small handful are maybe not more or less important but they may have a greater impact on the finished product.

[ZooCity]

Some of you all might've followed some of my posts and know that I went from statics in the early days and then, much like Alan, got a tension meter and confirmed that yes, that one screen the prints white real nice is at higher tension than the others.  From there I went to Newmans at first with 'standard' or 'T' mesh at 'medium' tensions, then with Roller Mesh at 'extreme' tensions (all were over 40n/cm with some much higher) and now I'm just tickled shitless with low-mid tension (around 26n/cm on average, some a bit higher) 'S' mesh or thin thread. 

Moose's post illustrates one of the things I really enjoyed with 'extreme' tension- consistency and repeatability throughout the chain as you called it.  High tension screens coat and print much more consistently than lower or mid tensioned screens do.

That said, this S mesh is the jam and I don't think I'm ever going back.  I printed a short job for and with friends for their non-profit the other night and used some of the 166 tpi roller mesh frames I had not been using in production.  They were probably around 45 n/cm.  I offered to let some of them print the Ts.  Well the print was white on black mostly and nobody could clear the mesh.  I got back on printing duty and found it to be brutal, I had to use a dry stroke to clear every pass.   With the thin thread meshes I could've been using a lower tpi that held more detail and cleared thick white ink like it was magic.  The Roller Mesh screen got the job done but that would've been half the physical strain and looked even better through a 150/48 S. 

S mesh is definitely trickier to coat consistently because of it's low tension and due to it's ability to let stuff just flow right through it.   It also take finesse and intuition to print with it manually- if the pressure and off-contact isn't very consistent and smooth yer going to see it. 

So, if we had an auto pushing ink around for us I might never have left the Roller Mesh and it's uber-tensions but as manual printers the ink clearing ability of thin thread meshes is really beneficial.   It's also taught me a lot about ink rheology and now, when we do ever get an auto I plan to stay with the S meshes. 

If the S mesh would stabilize at 24n/cm or above across the board of all mesh counts I'd have no problem using statics again, it'd be great.  As it stands, I find the roller frames to be critical in keeping this stuff as close to it's max tension as possible.  There's a monumental difference between 20 and 26 n/cm in terms of print quality in my opinion.  With the uber-tension mesh it would all stablize at not lower than 40 n/cm typically and there really isn't a huge difference between that and 55 n/cm. 

My 2 on it.  Good thread. 

[rmonks]

I  have both newman and aluminum static, I haven't had alot of time to test, and research the difference, but I do find that I am cleaning and reclaming more of the newmans than the static, it seems to be my frame of choice. I must admit I get an "F" when it comes to checking and keeping the tension up to par. I would like to know how many people that have newmans have the newman stretching table. I made a table to clamp them down but it seems i don't have time to rework them.

[Screened Gear]

How good are the panel Frames? I just watched the video. For the price they look cheap and really easy to set up (much like the Surlocks) How are the tension on the Panels???

[tonypep]

Well I've used just about everything over the years. Is tension overrated? By some I believe yes. Where does it matter most? In the underbase. Will you use less ink with higher tension? Doubtful. Does higher tension result in better registration? I've yet to see that. I've also yet to see that it increase set up times. Will higher tension allow you to print faster? Well you can usually speed up the stroke providing you have a well calibrated press but there are so many underlying constraints with regards to automatic production that you may find that, after admiring how quickly the squeegee travels you might still have to wait for that 3 second flash delay, operator fatigue, and dozens of other variables that can and often do restrict throughput (which by the way are so often overlooked while trying to obtain that perfect tension level). And with regards to print quality some of the best prints you will ever see have been printed with statics and I dare say I have seen some pretty substandard work on high tension  as well as lower tensioned screens. This enforces some of the above statements that while this is an important variable it is but only one of hundreds involved in the process.
So what is the least often mentioned benefit of higher tension? In my opinion it is smearing of successive colors when printing on solid plastisol underbases. There are others of course but I can tell you there are so many shops out ther that use roller frames and never re-tension; simply re-mesh as required. This is merely an observation; I do not by any means encourage this. Conversely whats the point of having re-tensionable screens if there is no time in the cycle to measure and adjust?

I've been considering my approach to increasing the quality of my screens for a while now. In the end I have decided to build a stretching table and start testing new fabrics. I'm in the vast minority here but I'm confident this will allow me to bring the variables back under control without causing delays in production. I'm going to get skewered for this but I am not in the screenmaking business I am in the screenprinting business.
Pierre is on his way here for a brief visit before leaving for New Orleans and I'm sure this topic will arise and he may wish chime in with his thoughts.

Finally kudos to those who have the time and inclination to keep pushing forward with this important but singular variable and continue to share their observations and experiences. It does not go unnoticed. We may agree to disagree with this sometimes sensitve subject but in doing so the learning process continues to improve.

[mk162]

Thanks, Pierre, for not stopping by my shop, it's ok.  I understand.   

[alan802]

I won't disagree with anything Tony said except the difference in setup times.  I stand by everything I've said about high tension but Tony has been at this way longer and I don't have concrete, measured evidence about ink deposit and stuff like that, just an overall inclination that high tension has done great things for us.  All of the "sales person claims" about high tension have turned out to be at least mostly true from what we can tell and I haven't seen anything that would lead me to believe that any of those claims weren't factual. 

We changed a few major variables and the way we did a few things all at the same time so I can't sit here and say that high tension is the only reason why our setups are much faster now, but I just "know" that it was the main reason why our setup times have decreased drastically.  I remember setting up a six color job with our statics and doing 20 test prints to get everything registered correctly and getting all of the print settings nailed down right so the ink deposit is quality.  Now, if I'm setting the job up, a six color might have 3 test prints done on it, and most times, 2 and we are running the job. 

And I know for sure that higher tension screens have allowed us to very rarely ever need to double stroke, along with many other advantages I've noticed, I just wish I could actually measure these results. 

[IntegrityShirts]

How good are the panel Frames? I just watched the video. For the price they look cheap and really easy to set up (much like the Surlocks) How are the tension on the Panels???

I have four panelframes with 230 mesh.  I would not buy them again.  Tightest screen was around 17nm stretched and then relaxed even lower.  My statics are better than these.  I tried researching them before I bought, read about bad mesh being replaced with good mesh, figured they had the kinks worked out (like testing each panel tension before shipping).  Then after I bought them they announced that the Chinese mesh supplier STILL wasn't cutting it with QC and they were reorganizing to use panels made here in the states.

If you do decide to buy some, make sure you confirm the source of the panels.  I'm going to try double-rolling one end and see if I can get over 20nm.  I'll put the tension meter on them as I do it and if they pop below 30nm I can blame the quality of the mesh in addition to poor construction.

They still print okay, but no where near their potential in my opinion.

[alan802]

I've got 4 panel frames and I bought them when they were new and the old china mesh.  I have been disappointed with many products over the years but this one was possibly the biggest.  I bought 10 panels for 4 frames and I ripped only 2 of the 10 panels when trying to stretch.  The tension levels I recorded were in the low 20's, I think 22 was the highest.  After a few hours they had relaxed to 17-18 newtons.  I've still got them out there and 3 of them still have mesh in them.  I may just go measure them real quick for shats and gaggles.

I tried the double roll technique and it added tension but it also added too much stress for that mesh to handle and most of the double rolled panels ripped.  I still maintain my stance that they could be a very good product, a possible game changer but it's been a year now and they've yet to reach that potential that I thought they had.

[Screened Gear]

So panels are out. Here is a my question. I use statics now. I get 18 to 22n on them. They print fine but i would like to be consistently around 25 to 35n.  I don't want to use Newmans. Is my only option Surlock frames and the conversions? Alan you never gave your feed back on the Conversions in that old thread. I am interested to hear about them.