TSB
screen printing => Screen Making => Topic started by: noortrd on July 25, 2014, 04:38:45 PM
-
Any body tell us the best emulsion for high density?
-
Cap Film. However Xenon does have a very "High" gasket emulsion called QXL.
-
I know I am plugging something I sell here; but the Murakami Aquasol HS.
https://www.youtube.com/watch?v=yfk1nOpbL0Q (https://www.youtube.com/watch?v=yfk1nOpbL0Q)
I have a couple customers using this for HD and they swear by it. Above is a great video Al made of how to coat with it.
-
I need to pick some of that up next week along with some HD clear if you can get it in :D
-
We looked at high density a number of years ago, did the experiments, showed it to the customers. Impressed, but would not pay for it. Tried the Fat film, multiple coats to build up liquid emulsion, exposure testing, all the rest, zero interest. Go figure... We bought some kind of clear ink and some new fat film about 4 months ago (not aware of this one, my partner wanted to try it) then got so busy we completely forgot about it. We just don't have any requests for special effects inks, other that regular metallics. I have not had one single request for foils ever, haven't done puff in over 10 years, maybe some glow in the dark every couple of years. I'm guessing they are cool
if you're selling a line, but offering it for contract purposes just seems to price it out of their comfort range.
Steve
-
Use cap film, 300 or 400 microns. Depending on inks / substrates and learning curve you will have amazing results.
In my opinion and that is all it is don't waste time "building up" your emulsion with coating. Get some cap film samples from your rep and then buy a pack of the desired micron thickness. Your coating will not work or match the cap film at all. Time is money and you will waste it.
The sad part is once you do that job unless you are a huge contract shop or that client moves serious numbers that pack of 400 micron cap film is going to sit there forever. Might as well do some cool shirts for your own shop!
-
On the topic of HD inks, does anyone have any experience or tips for doing a transfer using the stuff? I have a client that is interested in having an HD clear seal put on some caps. While I could direct print, I usually prefer pressing transfers on caps. I'm worried it won't cure properly or hold its shape/density properly with a press though. Just interested if anyone has tried this before.
-
Pressing HD basically just smooshes it down. Kind of makes it pointless, ya know?
-
We looked at high density a number of years ago, did the experiments, showed it to the customers. Impressed, but would not pay for it. Tried the Fat film, multiple coats to build up liquid emulsion, exposure testing, all the rest, zero interest. Go figure... We bought some kind of clear ink and some new fat film about 4 months ago (not aware of this one, my partner wanted to try it) then got so busy we completely forgot about it. We just don't have any requests for special effects inks, other that regular metallics. I have not had one single request for foils ever, haven't done puff in over 10 years, maybe some glow in the dark every couple of years. I'm guessing they are cool
if you're selling a line, but offering it for contract purposes just seems to price it out of their comfort range.
Steve
Goes under the category of can you vs should you.
-
Never tried HD but use Satti PHU emulsion which will build an incredibly thick stencil with ease.
-
We looked at high density a number of years ago, did the experiments, showed it to the customers. Impressed, but would not pay for it. Tried the Fat film, multiple coats to build up liquid emulsion, exposure testing, all the rest, zero interest. Go figure... We bought some kind of clear ink and some new fat film about 4 months ago (not aware of this one, my partner wanted to try it) then got so busy we completely forgot about it. We just don't have any requests for special effects inks, other that regular metallics. I have not had one single request for foils ever, haven't done puff in over 10 years, maybe some glow in the dark every couple of years. I'm guessing they are cool
if you're selling a line, but offering it for contract purposes just seems to price it out of their comfort range.
Steve
Goes under the category of can you vs should you.
Agreed! Live and learn
Steve
-
We use the Saati PHU for thick screens. Not much in the 3-400 micron thickness these days, but we coat out 83-70 mesh with it to make a fairly thick stencil for our bacon scented prints. We could get 300 plus microns coating wet on wet (no "face" coats) If you're CTS, consider the additional thickness in relation to your print head.
-
As Kevin mentioned, Aquasol HS can build thick stencils easily and yields a very flat print surface. Coated with dull edge very slowly: 2 on print, 6 on squeegee side achieves a 400 micron stencil, about the most you will ever need. You can drop the number of coats to achieve 200-300 micron stencils as well. Expose 1.5 minutes per hundred microns.
Coating - Yield
1:1 = 95 Microns
1:2 = 135 Microns
1:3 = 218 Microns
1:4 = 273 Microns
1:5 = 335 Microns
2:6 = 400 Microns
Usages: Glitter, Gels, Blister Puff, Puff, High Density
For High Density prints that are stacked, or need extremely sharp ink edges and flat print quality I recommend Murakami Thick Film, the original fat film. It has very sharp ink gaskets and vertical side walls for crisp print corners and details and provides excellent resolution for textured prints using HD inks.
-
Al: has anybody exposed this on a M&R Starlight? 1.5 minutes per 100 microns seems really long on a LED unit...
-
Yes the Starlight will have a shorter exposure. From my tests with emulsions it exposes a screen in about half the time. Notice I say expose, since there is a real misconception out there that a short exposure that achieves an image is a good exposure. Like a cake, you have to bake any screen completely for it to work. My guesstimate is 45 seconds per hundred microns. We should have one here shortly to run tests on. A step test with strong lettering or solid graphics would help dial it in at any shop. Based on the time above, if I had a 300 micron stencil the time should be two minutes, 15 seconds. So on the test I would run a 1 minute panel test to give me a step test of 1,2,3,4 minute exposures on one screen and evaluate edge quality, and the corner sharpness of letters along with how well cured the inside of the screen is during development. No slime, no soft emulsion.
Al
-
I don't know all the statistics for every emulsion but a quicker exposure is not always better.
We have printed hundreds of thousands (literally) of shirts with high density ink and I don't know why you would want to try and do it with liquid emulsion. Just figure out how to do cap film. We use Saati cap film and I'm sure a rep will show you how to do it. Murakami cap film is also good for printing HD. We have not found any of the others to work well in our shop and I think we tried them all.
There are a few situations that you would use a thinner stencil (liquid emulsion) and HD inks, but there are not many. 300 or 400 micron cap film is usually the way to go.
-
The difference between Murakami Thick Film and Aquasol HS is what are you printing. If you are printing High Density Inks and need vertical sharp prints with super sharp corners Thick Film is the way to go. If you are just printing Gels, Glitters, puffs, etc then Aquasol HS is a less expensive solution. It coats wet onto wet, its the dry time that is very different. I can make a thick film screen in about an hour with a good drying oven. Aquasol HS is overnight with a fan on. Both have to be dry to use propertly.
Al
-
Using cap film is definitely the way to go, that's the easy part. After that, finding the best HD ink brand will be another challenge. We always found International Coatings to work well for us. Art considerations, print/curing parameters are the next step. Good luck!
-
when printing HD inks I have had better results using 150 - 200 micron film and more layers. this will give you cleaner crisper edges. remember to slighty and I mean slighty choke your top layers to ensure clean edges. also bump your mesh up on the top layer to eliminate mesh marks giving you a nice smooth finished print. now with gels the 400 micron is my choice. alsowhen printing minimal flood pressure will save you lots of problems
-
Another trick we used was to attach a 3" tapered piece of wood to the bottom of the screen so the squeegee rides up on a ramp right after printing. This separates the mesh from the ink quickly to avoid ink points and to get a sharper edge to the print. Quite often the squeegee pressure would cause the bottom of the screen near the end of the print stroke to stay in contact with the ink. having the squeegee ride up a ramp separated the bottom of the screen far quicker than waiting for the print stroke to finish.
-
Another trick we used was to attach a 3" tapered piece of wood to the bottom of the screen so the squeegee rides up on a ramp right after printing. This separates the mesh from the ink quickly to avoid ink points and to get a sharper edge to the print. Quite often the squeegee pressure would cause the bottom of the screen near the end of the print stroke to stay in contact with the ink. having the squeegee ride up a ramp separated the bottom of the screen far quicker than waiting for the print stroke to finish.
YES Shimming the screens is necessary when doing multiple layers to keepe clean edges. also minimal to no flood. DO NOT FILL THE IMAGE ON THE FLOOD STROKE.