Tight Discharge Registration

[ericheartsu]

Hey All,
hoping you can help me with an issue that's been hurting my head all week.

Client ordered a pretty simple 2 color discharge print. Purple and White on a next level tee. We typically throw our discharge prints on 156 screens. Both screens are in the neighbourhood of 30n. Both colors were printing with the sharp side of a smiling jack squeegee, and both colors are printed with two passes. We tried getting it to clear in one, but the image was just to big.

What looks like is happening, is the print looks perfectly registered on press, and after the magic that happens in the dryer, it comes out with a weird purplish-y halo in the center of the image, around the dots and top of the building lines.

What is causing this to happen? Is it loose mesh? to much ink deposit? shirt pulling up?  We are still getting some zombie skin as well, and we still can't kick that either!

I even threw this design onto my manual, on a new set of screens, same specs, and although i was getting it a little less, it was still there, and still happening.


Print size is 12" wide x 14.5" tall.
Purple discharge is mixed from Texcharge fluorescent magenta and blue r/s. Added 6% activator, no retarder.
White is CCI white with 4% activator, no retarder.

[mimosatexas]

You could either add a gutter of 1 point and expect the bleed/blur, or even flash the white first, or up the mesh count on the purple.

[Evo]

You could either add a gutter of 1 point and expect the bleed/blur, or even flash the white first, or up the mesh count on the purple.

The gutter would help but yeah, too much deposit, the ink is bleeding together as it evaporates in the dryer. I'd print/flash the purple first (drive it into knit) and lay the white on a little lighter.

[Screened Gear]

What was the print order? If white then purple that is the problem. White always last.

If that is not it then check your off contact. Make sure that is at zero.

Another option is to make sure your not hard flooding a print with that much open area. It will over fill the gasket of the stencil giving you blurry edges. I like to soft flood so there is about a 16th to 18th inch ink on the design.

Those are what I would check. Flashing the purple would get you by but finding the reason will make you a better printer and save you time on the next job. Good luck.

[ericheartsu]

I started with the purple first than the white. History has always had me printing white discharge/wb last, as it's usually the tackiest of all the colors, in my experience. I also tried doing white than purple, and had gotten slightly better results.

On the manual i tried heavy flood, light flood, and even no flood. No flood yielded some good results, but eventually with two print strokes, it started popping up again.

I'm going to try upping the mesh count to a 230 on the purple over the weekend (i don't have any 200 manual frames), I'm just worried it's going to dilute the purple on the print.

i started with zero off contact, and worked it up to about 1/16th, which was giving me a little bit better prints as well.

Thanks for the help so far!

[Screened Gear]

I have to say, printing a big print with that much open area manually is going to cause problems. I don't want to be the one that tells people you can't print waterbase manually. You can. It is just a lot harder when printing multicolored tight registration stuff.

"No flood yielded some good results, but eventually with two print strokes, it started popping up again."
This makes me think your laying down to much ink on the surface of the shirt. Either your not printing hard enough, you have too much EOM on the screen or your flooding to hard.

I think your right to up the mesh count. That will make the printing and flooding easier to control on a manual press. It will also lay down less ink. This will make it harder for the colors to mix. I think 230 is fine. I've printed DC on 305 manually with no problems. DC is easy to print on higher mesh.  Make sure your purple ink is on the runny/wet (not sure how to communicate this: you want it so it will run off a goop scoop when vertical but not run when sitting on the screen). It will soak in easy that way. Do a nice hard print. Be very consistent with your print. Every few prints check the screen to make sure ink is not mixing on the underside of the screen. If it is then your not printing hard enough or your flooding to hard.


Flashing that purple is a good idea to get the job done.

I know I rambled on a little here. Screen printing for me is problem solving. To fixi the problem you have to try a lot of options. I am just trying to give you thinks to check.

[ericheartsu]

Jon, i truly appreciate all the advice!

I'm gonna try upping the mesh count and see what that does.

I switched it to the manual from the auto because i was getting frustrated, and wanted to free up the press to print other jobs. But i typically find it easier, or at least more consistent on the auto!

[ericheartsu]

Threw this up on the manual again today. put the pupre on a 230 screen, using the sharp side of a smiling jack manny blade. White through a 160, sharp triple duro.

Printed the purple (2 hits), flashed it, printed the white (1 hit), put it through the dryer

That halo affect is still there, not as present, but the inks are def. still blending. Should i try putting the white on a 230?

[mimosatexas]

build in a gutter of some kind.  There are a lot of possible reasons for the bleeding (flooding too much, angle of your stroke, the fabric, etc.) and you might just have to compensate by giving it a small gap to compensate, which will fill in when printed.  You shouldn't need two hits of any ink though (imo) if it has the proper water content.

[ebscreen]

I'd put the purple on 230 and the white on at least a 180 probably 230.

We don't flash between colors with discharge. Typically causes more problems than it fixes.
IE you can lose tack because it starts steaming off a bit, inside the shirt.

Put it on the auto with higher mesh, try a 60 blade, straight up and down, pressure to give you some angle
and funnel, and a superfast stroke, thick flood. That gives us the best penetration and least gain.

[Screened Gear]

Was this problem ever solved?

[JmanRT]

yeah i would say definitely up your mesh, 225-230 whatever in that range that you use. it seems like your getting saturation in the shirt you dont see on press but after its activated the purple is coming visible under the white.
we actually use our flash pretty often and we exclusively print with discharge inks at my shop,

-- this would be my print order
 white on a 225 x2
 flash
 purple on a 225 x2

i think that would work just fine

[ericheartsu]

We got pretty close. i don't know if it was perfect. We ended up putting a gutter in, upping the purple to a 230 mesh, flashing, then printing the white through a 205.