TSB
screen printing => Waterbase and Discharge => Topic started by: andyandtobie on August 25, 2014, 12:15:35 AM
-
Hey guys, thanks for the help with the first couple of questions I posted on here, every tip we got was helpful! We're working through a 180 piece job that's a handful of shirts of almost every kind. There's cotton, 50/50, tri-blend, etc. Anyway, we're printing on a 6/4 manual, with static 230 screens coated 1/1- it's what we've got to work with for now. This is a five-color job with a big "slab" underbase of white. Underbase white is Green Galaxy Comet White, with Matsui top colors and Matsui undercoat binder in a 110 screen for the poly shirts to stop migration. The Green Galaxy seems to be printing well in our hot, dry climate. These prints were looking great until today, when we started printing on District DT1500 tank tops that are 3.8 oz ring-spun cotton. The white won't hardly clear the screen! Tried a P/F/P and most of the ink is still loaded in the stencil, leaving a white "ghost" of the print on the shirt and that's it. Any ideas? Is this a "hard flood soft stroke" thing? Money's tight for us, and my wife and I are desperate to get this job out the door and paid!
-
maybe too much heat on the flash..try a push stroke..
-
I am not in any way an expert in today's waterbase inks, but I'm curious as to if you were to print one of the other type of shirts that have been successful in the past, would it work?
I am guessing no, because it sounds simply to me that the ink has dried in the screen.
You say that in general, this ink performs well in your climate, but, there must be a tipping point.
-
I'm gonna agree with Andy on this one. Sounds like classic dry in. Modern inks or not, the result
is still the same.
-
I don't know the inks your using. I used Matsui a few times about 4 years ago and didn't like their products. I know they have got better since then but I just don't use them. The fabric will print a little different but not like your saying. It does sound like you have dried in ink in your screen. You said your printing a hard stroke and soft print? That is not how I print waterbase inks. I do a soft (just enough presure to cover the design. then a hard print stroke. WB inks need to be pushed into the fabric. A soft stroke does not do it. It will also leave ink in the screen. This ink will dry or clump in the screen if you don't hard stroke them out. Retarders and additional water will help.
-
WB inks need to be pushed into the fabric.
I agree with that statement concerning all wb inks except white (edit: and metallics), which should be printed on top of the fabric similar to plastisol for best results.
I haven't used the Green Galaxy inks, but I'd imagine that printing a 5 color job on white manually would leave a bit of time for the ink to begin drying in the screen between shirts. As others have mentioned, using retarder or wetting agent will help a bit, and if you aren't already, make sure to flood the image area of the screen when not in use.
-
Ha! Well it looks like my post from this morning didn't go through! :o I had said that maybe the P/F/P heat may have dried some ink in the screen, but sounds like everyone else has that covered! Take the ink out, wipe the screen with water well, and mix some water into the Comet white and give it another try.
-
Ha! Well it looks like my post from this morning didn't go through! :o I had said that maybe the P/F/P heat may have dried some ink in the screen, but sounds like everyone else has that covered! Take the ink out, wipe the screen with water well, and mix some water into the Comet white and give it another try.
I've had brain farts and hit the back button instead of post, and lost what I had, if I even noticed what I did.
-
I'm pretty sure it was because our WiFi wasn't working when I woke up this morning and I get pretty much zero cell reception! I can't tell you how many emails have gone unsent because of that!
-
Wow, thanks again guys, you're all a huge help! Boy, do I feel like a dope. Sure enough, it was just dry-in. Just happened to be that I'd already printed a shirt that looked fine, stopped to fix a registration problem, and when I started again, the next shirt just happened to be one of the ring-spun cotton pieces. I feel like a dork for not realizing that was all it was, but at least you guys kept me from running around in circles all day. Apparently the Comet White had been gradually loosing a little water over time, but hadn't shown any real sign of a problem until as Frog said, it reached a tipping point. We mixed a surprising amount of water back in, stirred like crazy, and went back to printing nice, smooth underbases. Thanks again, guys! This place is great!
-
Ha! Well it looks like my post from this morning didn't go through! :o I had said that maybe the P/F/P heat may have dried some ink in the screen, but sounds like everyone else has that covered! Take the ink out, wipe the screen with water well, and mix some water into the Comet white and give it another try.
I've had brain farts and hit the back button instead of post, and lost what I had, if I even noticed what I did.
When you have even the hint of a long reply, use Notepad to type it all out and then copy/paste.
-
I saw mention of a 230 mesh being used, if not a thin thread "S" mesh that may cause a drying in problem. Also, be cautious as to how much you may alter the chemistry of water based inks with any addition of water, retarders and/ or fixatives, it could lead to curing problems.
-
I definitely second using either S mesh or a lower mesh count. I have had ZERO drying in issues since switching to 225S for my waterbased prints.
-
Yes, I've been worried about causing trouble by adding the water, but our ink starts turning into cheese within twenty minutes. My wife and I have come up with a workaround, where we keep two small containers of each color. When the ink on the press starts to get dark and thick, I scoop it back out into its container and load the fresh ink from the second container. Then Tobie takes the cheesy used ink and sprays it will distilled water and stirs it like crazy, then puts the lid back on for another twenty minutes or so and then we switch again. Of course, with that happening in each screen, it seems like we're changing ink almost as much as we're printing, but at least we're moving forward this way and getting nice prints into the dryer. We've got some glycol retarder, but I'm hesitant to use it because our dryer is a silly little tiny thing. I'll probably try a little retarder in a test print soon and wash test it, to see if we can get away with using it.
As for the Murakami mesh, thanks for the tip! Wow, if it works that well in Texas, it's got to work here. We'll be ordering some immediately to try on our next job. Thanks again, guys!
-
Keep a spray bottle by the press. When we run Comet white we spray it while it is flooded every now and then, not a lot just 2 or 3 mists. Another thing we do is spray a good dozen mists in the bucket(5 gal) after printing at the end of the day before closing it up. If you use the Comet everyday I would spray it less though.
-
Thanks, Alex! When we ran Comet the first time, I was spraying it with a couple mists once in a while as you suggested. We'd flood, mist it a little on top of the flood, then let the squeegee mix the water in. Our problem was that the individual droplets from the mister would create tiny pinholes all over the print. Took us forever to figure out where the pinholes were coming from. We went to spraying in the bucket and stirring, and no more pinholes. Maybe that's just something that's been an issue for us?
-
I'm taking a fine mist, no drops or, well you found out :(
-
Yep...fine mist will work fine, have done that on the auto when it's flooded quite a bit. We get a couple water based jobs of over 1k shirts a year and need to do it during those runs.
As for your printing problem, lower the mesh count or get thin thread mesh. Keep moving quickly while printing, take a break with clearing out the whole image with wet rags at some point then continue later.
I'm a fan of 150S mesh for water based ink though, 225S for detail I suppose.
If you use 135S the ink drips through if left flooded for more than 15 seconds, we made that job work and it was easy but you had to keep moving fast otherwise the edges would be smeared from ink dropping through the screen lol.