# How to keep platens cool enough for waterbased...



## Kime (Aug 1, 2008)

We just printed our first job on our new used auto. The fronts were one color and we were able to print the Permaset gold ink on black shirts without needing a flash and got fine coverage. Printed 500 shirts with no loss of detail in the print. The backs were 2 colors and we had to flash after the first color to keep the ink from pulling up on the back of the second screen. We had 4 stations for cool down and put a fan on the station after the flash. We have a quartz flash and after the platens heated up we found that we could lower the flash time to about 4 seconds. The problem was that the platens still heated up enough to cause the fine lines in the print to dry and after about 100 prints we were having to keep stopping to try to get the screens clear. 

Does anyone have any suggestions on other ways to keep the platens cool? Would a forced air flash work faster without heating the platens so much? Has anyone done longer runs with permacet ink with a flash and high mesh screens (we were only using 156 mesh, but would like to be able to use higher mesh and be able to just have one cool down station) that can tell me how they keep the screens from drying? We are flooding, but I am using the squeegees for flood bars because the floodbars that come with the machine don't get the supercover ink down into the mesh and I had to use more strokes to get a good print. Maybe I need to go back to the old floodbars that leave a layer of ink over the whole screen instead of just in the design itself and use more strokes, but the extra strokes slow down the printing, but the drying problem slows down the printing, too, and causes more bad prints. 

Has anyone found out how to overcome these problems?

I want to mention that the supercover ink printed with no flash between the same color strokes came out fantastically soft with good coverage on black shirts (metallic gold and mid red), especially after washing.


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## mikelmorgan (Nov 1, 2008)

It sounds like the flash may need to be longer. When we get lines like your describing, it's because the ink is not dry all the way. The ink is dry where the bulbs are but not over the whole print. Good Luck


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## Kime (Aug 1, 2008)

It's the lines I am not getting that are a problem. It's because the ink is drying in the finer parts of the design in the screen.


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## splathead (Dec 4, 2005)

You may need to slow down your carousel and let the fan cool the print longer before the 2nd coat.

Is wet on wet printing an option?


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## tlbays (Apr 9, 2008)

Hi Kime

Are you currently using a Retarder Additive?
Here's an example link of what is available for your brand:
Permaset Aqua Ink Retarder - Water Based Screen Printing Inks
Although a guerilla tactic, it can widen adjustability of ink drying.

Joe's got a good point; one of the benefits of water-base is a normallly lower ink tack that permits w.o.w. more often.

Note that sharp squeegees are also very important to clean ink release and fine details.
More upright squeegee angle + slower print speed is often more beneficial than the opposite.

Regarding pallet temperature, many waterbase ink formulas actually perform best onto a warm surface.
It compensates for the cooling of the screen through evaporation, aiding ink flow.
Here's an example of a tech sheet suggesting 140F degrees:
[media]http://www.advancedscreenprintsupply.com/TechData%20Matsui%20301%20Series%20Overview.pdf[/media]

Happy trails!


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## Kime (Aug 1, 2008)

tlbays said:


> Hi Kime
> 
> Are you currently using a Retarder Additive?
> Here's an example link of what is available for your brand:
> ...


I forgot to mention that I *was* using retarder. I will experiment with squeegee angle and print speed more. The squeegees are new and sharp. The Permaset supercover inks are thick and not low tack. The regular colors work much better for wet on wet, but you have to print them on a flashed underbase on dark garments. 

The printing went great for the first 95 shirts or so, it was when the pallets got too hot that we started to have problems, but I don't know how warm they were. I didn't turn down the flash time soon enough because I was turning the wrong control for a while until I figured it out. (It was the first time I was in charge of the flash since we got it.) Maybe if I had turned it down sooner the screen wouldn't have gotten partly clogged.


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## Kime (Aug 1, 2008)

splathead said:


> You may need to slow down your carousel and let the fan cool the print longer before the 2nd coat.
> 
> Is wet on wet printing an option?


We tried wet on wet, but the ink was sticking on the back of the screens and leaving a blotchy print. If someone has figured out how to get good coverage with supercover inks on black without using a flash printing wet on wet I would love to hear about how they do it.


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## tlbays (Apr 9, 2008)

Hi Kime

Although I'm short on expertise regarding Permaset,
water-based inks evaoporate as they sit open in the screen, changing viscosity.

Perhaps your initial run success also lessened as the water component left.

You can do do things to rectify this;
-Keep ample amounts of ink in the screen to rewet throughly.
-Use a fine mist sprayer with water to _sparingly _add any moisture that has wicked off.

One more checkpoint.....make certain that your emulsion is not slowly degrading....
Often, this can appear as latent "clogging" when printing waterbase inks.

It sounds like you're pretty close to isolating the problem.

Happy trails!


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## ufc1972 (May 28, 2009)

I use permaset ink and found that that aluminium platerns with the rubber on top help to keep the temp down and also I poor a few litres of water on the concrete under my press to help get the humidity level up. Dont know if this really works but I print in a confined area so I really do think it helps. I have never needed print retarder either but the climate where I live is water based friendly. 
How do you get a good coverage with just one print of the gold I alway have to PFP to get a good coverage?


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## Kime (Aug 1, 2008)

ufc1972 said:


> I use permaset ink and found that that aluminium platerns with the rubber on top help to keep the temp down and also I poor a few litres of water on the concrete under my press to help get the humidity level up. Dont know if this really works but I print in a confined area so I really do think it helps. I have never needed print retarder either but the climate where I live is water based friendly.
> How do you get a good coverage with just one print of the gold I alway have to PFP to get a good coverage?


I didn't say I used only one stroke, but only that I don't have to flash to get good coverage. I do 2 or three strokes in a row without a flash, then flash if I have a second color. This didn't work when I was printing manually, only with the auto which has a much more consistent stroke.


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## ufc1972 (May 28, 2009)

I know you ment a few stokes, I meant just without the need for another print after the flash. How close to a PFP brightness is it.


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## Kime (Aug 1, 2008)

ufc1972 said:


> I know you meant a few stokes, I meant just without the need for another print after the flash. How close to a PFP brightness is it.


I am afraid I don't know anything about PFP brightness, but here is a closeup photo that gives a pretty good idea. From close up you can see a bit of the black coming through but from a couple of feet away it looks plain white. I am sure print flash print would be whiter, but I think this is an acceptable white for many images but maybe not for large areas of plain white.


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