The right squeegee?

[Prince Art]

We recently brought in a used Brown auto. Ran a job or two on the old 70 duro squeegees that came with it, had some problems clearing screens in one stroke. But the blades were dull, and we didn't really have all our other parameters dialed in yet. I've since replaced the blades with 70-90-70, and now I'm still having trouble completely clearing the screen with one stroke.

-We're using standard mesh, and the problem is in all mesh counts. Tension isn't great in some screens, but others are tight.
-Inks are mainly Quick White & Epic PC mixed colors, but that doesn't seem to matter. Same thing happens with Rutland M3 & One Stroke ELT-S
-Off-contact @ a little less than 1/8". (Estimated.)
-Pressure is really cranked down.
-Squeegee angles used have been between about 22-45 degrees.

So, could the squeegee duro be a contributor? Is there another option that might help correct the problem?

(While I'm at it, is there anything that would be a little more forgiving in subtle difference in pallet levels? We've also had some issues with getting consistent tones across all pallets when printing very large gradient halftones.)

[Admiral]

I would try less angle, if you are having to use a ton of extra pressure it is adding to the angle and possibly not making a good shear at all, skimming a bit instead of printing with the sharp edge.

I do know though that some presses are harder to clear ink with, smaller chopper cylinders and pneumatic stroke instead of electric.  I know the Brown is electric, I don't have experience with that specific press in production.

[Doug B]

  I would agree too much angle especially with 70-90-70.

[Atownsend]

My $0.02.... before you do anything level the pallets with a floodbar. And If you have bad pallet deflection even with minimal pressures like we do, consider adjusting your pallet level to compensate for the deflection. This will help with getting consistent gradients. We level to dimes up front and nickels in the rear to compensate. I move the flood bar and adjust the pallet until each side of the flood bar barely scrapes the top of the coin. Maintain this, or you will run into clearance / print quality / registration issues if it is real bad. Then check / set off contact. 70/90/70 squeegee @ 90 degrees or close to it. Dial your pressure in slow over a series of prints going from not clearing to just having the ink sit on the shirt. Consider using 150/48 or 135/55 for your base whites.

[Prince Art]

I'm sorry, I've probably described the angle incorrectly. I was thinking of vertical as Zero degrees. And even at that, I was wrong. If vertical=0, angles I've tried have been near vertical to a max of 45 degrees. If 90 degrees= vertical, the shallowest angle I've tried is still about 45 degrees. Does that make sense?

To my knowledge, close to vertical = better shear. Is that correct? If so, since I've combined that with a lot of pressure, I'm not sure angle is my problem. Unless I'm missing something.


And the Brown approach to squeegee pressure is pretty rudimentary. It's entirely mechanical; squeegee (and floodbar) height & pressure are controlled by a combination of spring & adjustable threaded rod. Left/right are independent of each other. A lot is left up to feel, and adjusting until you get acceptable results.

[Prince Art]

My $0.02.... before you do anything level the pallets with a floodbar. And If you have bad pallet deflection even with minimal pressures like we do, consider adjusting your pallet level to compensate for the deflection. This will help with getting consistent gradients. We level to dimes up front and nickels in the rear to compensate. I move the flood bar and adjust the pallet until each side of the flood bar barely scrapes the top of the coin. Maintain this, or you will run into clearance / print quality / registration issues if it is real bad. Then check / set off contact. 70/90/70 squeegee @ 90 degrees or close to it. Dial your pressure in slow over a series of prints going from not clearing to just having the ink sit on the shirt. Consider using 150/48 or 135/55 for your base whites.

I have levelled the pallets; but it's possible I haven't adjusted for pallet deflection properly. The Brown has side clamps, toward the rear of the screen. This allows more flex in the front end of the screen. So, I've adjusted screen angle higher in the front, with the idea that once squeegee pressure hits the front, off-contact is about right. (This was the same approach I took for setting OC my manual press, and it worked there.)

Have used 156 for base on multi-color, and 156 or 110 on PFP white. Still end up double-stroking. I think the only thing we haven't had to double-stroke has been spot colors over a smooth UB, through 230 mesh.

[Atownsend]

No experience with this press, but on ours we have a depth adjustment for the squeegee pressure. Is the "depth" the same from side to side on the print head?  Maybe one side is slightly lower or higher than the other throwing things off for you. If the pallets are level you could take a magnetic level and attach to the carriage where the squeegee sits to make sure they are equal on both sides. Some folks swear by double bevel squeegees, but I have yet to try one.

[TH Apparel]

Is it not clearing in certain spots?
Like the top of the prints don't clear, but the rest do?
We have some pallets that do not clear in spots, but it's because our pallet rubber has really small indents on a few.

[Prince Art]

No experience with this press, but on ours we have a depth adjustment for the squeegee pressure. Is the "depth" the same from side to side on the print head?  Maybe one side is slightly lower or higher than the other throwing things off for you. If the pallets are level you could take a magnetic level and attach to the carriage where the squeegee sits to make sure they are equal on both sides. Some folks swear by double bevel squeegees, but I have yet to try one.

The squeegees don't have a singular depth adjustment. Just right & left, which get screwed down or up to increase/decrease depth/pressure. There's no predictable way to guarantee even pressure. I just dial it down until the screen seems to be clearing evenly. The problem is that even with a lot of pressure, it seems to take 2 strokes for ink (plastisol) to fully release in all areas & leave an even coat on the garments.

I know the mention of double-bevel squeegees can elicit grins on this board - something of a running joke. But I know some people like them, and I've wondered if it would help in this situation.

Is it not clearing in certain spots?
Like the top of the prints don't clear, but the rest do?
We have some pallets that do not clear in spots, but it's because our pallet rubber has really small indents on a few.

Not sure how to answer this. It seems to be a side-to-side issue; it's not as though small pockets refuse to clear. The first head, at least, always needs more pressure on the right than the left. Which doesn't make sense to me, as I leveled to the first head. If any head should be consistent, you'd think it would be this one. Other heads may favor one side over the other, too, but I haven't really logged that carefully. Most of our work is 1 & 2 color, so some of the heads have only seen a little use since we got the press.

However, I've also experienced that sometimes the issue can vary intermittently - every so often a shirt will need a 3rd stroke to get full coverage. The pallet rubber, or possibly uneven pallets, could be a factor in that. I'll try to pay closer attention to that possibility when working on this.

[Atownsend]

Is your squeegee much wider than the image you are printing? I wonder if a shorter squeegee that isn't much wider than your image might help. The screen kind of acts like a trampoline so i wonder if a shorter squeegee with maybe 1/2" on either side might help maximize the force and help the mesh snap off the shirt better and release the ink better.

What are your pallets made of? We recently stripped off the rubber from ours as it was so old / domed / crapped out from over flashing etc. It made it difficult / near impossible to calibrate. It was so hard we might as well been printing on straight aluminum anyway. I have noticed better prints, but I'm sure fresh rubber would probably be superior to aluminum, but effed up rubber is definitely not superior to flat aluminum. As a bonus the pallets hold less heat so no more ink gelling in the screen when we are forced to send something around twice.

I downloaded a copy of Joe Clarkes "textile printers bible" and started reading though that last night. It looks like solid gold, lots of tips for press calibration. Not specific to your press but the principles should apply nonetheless. Maybe you can find something in there that is of use!

https://docslide.us/documents/textile-printers-bible.html

[Prince Art]

Is your squeegee much wider than the image you are printing? I wonder if a shorter squeegee that isn't much wider than your image might help. The screen kind of acts like a trampoline so i wonder if a shorter squeegee with maybe 1/2" on either side might help maximize the force and help the mesh snap off the shirt better and release the ink better.

What are your pallets made of? We recently stripped off the rubber from ours as it was so old / domed / crapped out from over flashing etc. It made it difficult / near impossible to calibrate. It was so hard we might as well been printing on straight aluminum anyway. I have noticed better prints, but I'm sure fresh rubber would probably be superior to aluminum, but effed up rubber is definitely not superior to flat aluminum. As a bonus the pallets hold less heat so no more ink gelling in the screen when we are forced to send something around twice.

I downloaded a copy of Joe Clarkes "textile printers bible" and started reading though that last night. It looks like solid gold, lots of tips for press calibration. Not specific to your press but the principles should apply nonetheless. Maybe you can find something in there that is of use!

https://docslide.us/documents/textile-printers-bible.html

Squeegees are 15"; prints generally max out around 12.5" (but we do that size all the time). I'll give shortening a few some thought.

Pallets are aluminum, but the top rubber is probably a valid concern. I don't think it's the cause of the problem, but I'm sure the level of wear isn't helping. Really don't want to have to strip 30 pallets (10 stations, 3 sizes) quite yet, though!

Thanks for the link. I'll look into that - I know Joe is a revered authority, but haven't read much of his stuff yet.

[RICK STEFANICK]

interesting? I would change the blades to 70/90/70. You know this sound stupid but we actually have had a similar problem on the older m/r's with too much pressure. ALSO if that press has head stands be sure they are secure in the floor and the legs are not popping out of the feet when printing. That my friend will cause exactly what's happening to you