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Aluminum frames are set in stone (glue) and can only be retensioned by taking out the mesh and redo them. They are sturdy and won't warp under heat. They also stand up well over time.

Roller frames take some time to be able to get the proces down correctly. They are nice because you can retention the mesh over and over. (I do not know much about the roller frames). From what I do know, they seem to be a good investment for the long run.
 

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Herbie:

Some thoughts to also consider is that unless you are doing a lot of high end work - simulated process, four color process, etc. - you can probably get by with using just standard aluminum frames and not go the roller frame route.

We outsource all of our frame remeshing to a company in Chicago - Graphic Screen Fashion. Frank does a great job, the frames have the right tension and hold up well. We also get them to apply a permanent block out around the exterior border of the frame and some special caulk where the mesh meets the frame. This allows us to print and use the frame without any masking tape at all.

We go through well over 150 frames a day (sometimes its double that), so this has saved a significant amount of labor and expense, and has added to our sustainability plan. We're still reclaiming and reusing the frames...but we skip the constant retensioning, and masking tape step.

Roller frames are great - (we use them too!) but they are a lot of work to keep up with, and if you aren't slated for high end jobs, they may be overkill.

Good luck,

-M
 

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I love roller frames, but still have more statics than rollers. Quality screens are essential for quality prints, as well as ease of set-up and use, no matter what style frame you go with.

Marshall makes a great point here--many people will post asking where to get the 'best deal' on screens, and it's often implied that this only applies to price. His is a post outlining a 'best deal' all the way around.
 

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What is the difference of Aluminum Frames and Roller Screen Printing Frames?

Everybody knows that tight screens print faster, thus better.

Higher tension means the mesh pulls itself out of the ink film.

Higher tension means you can print with lower off-contact, thus less distortion of the image as you bring the stencil in-contact with the squeegee blade.

Static or rigid frames can't retension mesh so your fresh, new, unstable mesh is continuously changing which may or may not frustrate your printing registration. Your critical first step in the judgement process is to buy a tension meter so you can learn how much your mesh is elongating from beginning to end of run.

Prepare for the shock as you find out hardly any static frame you use has more than 10 newtons of tension and know that snobs like me don't want to waste time fiddling with anything fewer than 25-35 newtons. Ask a friend or salesman to bring a tension meter to your shop so you can try, before you buy.

Roller frames do require more maintenance to keep the mesh "in tune" but that's the reason you would buy them. Increased production, easier printing and better registration will pay for the extra effort. If you don't want that, you've made your decision.

If you're having printing problems, there are lots of time consuming tricks you can use to avoid stabilizing or increasing mesh tension which won't fix or cure your problem, just prolong it like filling your car tire every morning before work rather than fixing the leak once and forever.

Manual Press
If you're a manual printer, buy aluminium frames because they weigh a pound less than well built wooden frames - so you have less weight to spin around, and stop as you print, each, color.

Automatic Press
If you have an automatic press, weight doesn't matter - so you'll find wooden frames just as stable as aluminium. They both support mesh as well as the other - it's the mesh that betrays you as it elongates with every stroke of your viscous squeegee blade.

Stop now if you don't want to spoil your read with details.




FATIGUE AND COLD FLOW
Even if stretched properly, polyester will gradually lose tension. This is due to 'cold flow' characteristics of synthetics which causes them to adjust to the stress, (tension) applied to them.

INITIAL TENSION
Tension loss after initial tension is always critical. If you stretch and glue, you'll see a drop in tension as you cut the mesh from the stretcher and transfer the force to the frame. On retensionable frames, the number of Newtons/cm lost and how long it took will determine how quickly you can re-tension and how much higher you can go above initial tension, into the stratosphere of high tension.

When a polyester filament relaxes, it gets longer, and it takes the stencil image right along with it. Too much tension, correct tension, and low tension all cause different problems, solutions, and results, but they all have one trait: the filaments will elongate during printing.

If the filaments get longer, they loose tension. If the screen loses tension, the stencil changes size by getting bigger. When the stencil gets bigger, the image won't match the positive and you are out of register. There is very little you can do to fix this at the press because the image no longer matches the positive.

TENSION LOSS OR ELONGATION FROM BEGINNING TO END OF RUN
When you push on unstabilized mesh with the squeegee (you brute) you stretch the filaments. As you print, the change is gradual from beginning to end of run. If you were printing a single, first color on paper, each image would be unique and different -microscopically larger every time.

This is why graphic printers might print the first sheet again at the end of the run to see how much the stencil changed. This is also why graphic printers will re-stack the job so they can print the second color, on the first sheet, hoping they will both grow at the same pace. This can work - IF both screens start at the same tension and elongate at the same rate.

Textile printers don't have this same problem because we print one shirt completely as we progress through the job.

TENSION METER TO CHECK LOSS DURING RUN
You should monitor this change with a tension meter or (the hard way) compare the positive to the screen after the run. If there is a substantial drop in tension there has been a substantial change in image size.


If you lost tension, the positive won't fit the image anymore and you might as well reclaim the mesh. You can re-imaged that same screen with the same positive and the stencil will match the positive again, but alas the screen will have lost tension and ink won't transfer as well.

Chart the life of your test mesh as you retention it by recording the number of prints and the tension loss in Newtons/cc. If you still use stretch and glue frames, write the date, tension and number of prints progressively on the mesh with a permanent marker every time you re-coat the mesh. Everybody knows that a tight screen prints better.


Low Tension Problems Like Blurs
Low tension prints worse. The lazy mesh doesn't want to pull itself out of the ink film and the force of the squeegee, will roll the mesh in front of the blade lip. The rolling action smears the print and changes the size of the image making it hard to achieve good registration.

Experienced printers know how to combat this problem. THEY SLOW DOWN THE PRESS, and stop to wipe the blurry screens more often. Ask yourself, why do I have to clean the bottom of even a one color print?

Wasted TIME
Slowing the press reduces image distortion and the slower press speed lowers production. (Take your time - we've got all night). This one of the greatest causes of waste in the screen printing business.
 

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Great info (as always) although I'd say the choice of wood vs. aluminum--auto vs. manual--as to whether or not you're dealing with spinning the extra weight goes further than that.

With wood you'll be dealing with the weight from stripping and reclaiming, degreasing, coating, exposing, and prepping again before they go back on press. The reclaimer and I both were very happy to relegate wood frames to random 1-C save screens only...

I love the last paragraph:

"Wasted TIME
Slowing the press reduces image distortion and the slower press speed lowers production. (Take your time - we've got all night). This one of the greatest causes of waste in the screen printing business."

Not to mention the image distortion brought on by the larger off contact necessary with poor tension.

If you are an owner, take heed. If you are on hourly, shhh... don't tell anyone. :rolleyes:
 

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Tyson:

Wasting time in production is serious business and can lead to higher operating costs. I've always looked for ways to lean up the shop and keep things moving for better throughput.

If you are interested in some thoughts I have on this subject check out an article I wrote for Impressions last year:

How to Build an Accurate Production Schedule - Impressionsmag.com

Good luck,

-M
 
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