WOW discharge (walk me through it)

[ericheartsu]

We are gearing up to do a reprint of a design we've printed twice before, and both times had HORRIBLE zombie skin buildup, and caused a ton of problems. So i'm posting on the forum today, to ask for help so i don't have to deal with this issue!

I'm printing a three color discharge tee, on black next level 3600. Here is the image i'm printing:



I'm setting up and printing in this order:
1. Blue (166mesh)
2. Pink (166)
3. Yellow (205)

i am using sericol discharge and i used 3% activator for each. the blue and hot pink specifically had some mixing white in it. to be clear, NOT white. Xenon Nova Emulsion, that is exposed, and then post exposed (for 190 light units on a richmond screen maker) on each side.

Give me some tips, some advice so i don't have to deal with zombie skin! yuck! thanks in advance!

[ebscreen]

Higher mesh count, keep inks fluid (IE water) and keep moving. We find that we only
have issues if we stop for awhile for whatever reason, and the ink starts drying ON the shirts,
then it gets picked up on successive screens. Having screens set far apart on press (IE head 1 and 10)
will influence this as well.

Also, it's my opinion that screen quality will play a factor in this. If your screens aren't smooth
and hard they're more likely to start picking up ink on the back. We use hardener on both sides
of all screens for multicolor discharge.

[Inkworks]

And make sure you're driving the ink into the shirt, not laying it on top of the shirt.

[ericheartsu]

for all our discharge screens we coat 1/1 with the sharp side (per sonny's advice). We've never had issues with breakdowns with this emulsion.

We typically set up these jobs on head 1, 2, and 10. Should we keep them together? Typically we use smiling jacks, and print pressure is at 40

[ZooCity]

There's yer problem- when printing DC keep the heads right next to each other and move fast.  My printer setup a 2 color frequent repeat in heads 1 and 6 last week (so he could keep an eye on both screens easily running solo, makes sense) that is normally ran in consecutive heads and it was crazy how different the job ran v. having it in two consecutive heads.  Way more pickup, even a slight color shift on the first color down. 

So don't give the ink any time at all to dry between prints.  You're also dealing with some serious open area there so it might make sense to put the yellow down first, bump flash it and WOW the next two.

[ericheartsu]

I'll give the spacing a try for sure on this run. I believe we are printing it on Wed.

Whenever we flash it, i feel it loses the vibrancy, i'd also like to not flash it, as it's one more thing to keep an eye on!

[kingscreen]

If it were me, I'd print the yellow first, then WOW the blue and pink. I would likely run pink last. I'd put the blue and pink side by side. I'd print the yellow, quick flash it, and give it a cool down station. I'd go with all 180s. Also, I would use hardener on the bottom of the blue and pink screens.

That being said, I have no experience with Sericol so results may be different.

[ebscreen]

That yellow is a big area and gonna have a fair bit of white in it, I'd put it last.

Flashing can sometimes make this problem worse as it starts the drying process.

Tradeoff between printing blue or pink first, I'd aim towards the blue as the pink
probably won't like being stepped on.

Unfortunately pressure readings are dependent on physical height of the squeegee,
only way to measure saturation is to look on the inside of the shirt. I like to see at
least %50, on big ass areas like this I'd probably want to see more.

[Inkworks]

The only issues I've had with Zombie Skin is when the dry time between screens is just wrong. Move quicker and it doesn't skin over so it doesn't happen, move slower, or flash and it's too dry to pick-up on subsequent screens. I can't think of how a flash would make the colours less vibrant...?

[Evo]

I can't think of how a flash would make the colours less vibrant...?

Cause all the magic happens in the dryer. The discharge process needs water to work. The dryer heats the water, the reaction happens, the water is evaporated, the remaining small amount of ink resin is cured.

If you flash away most of the water, then the remaining reaction in the dryer can be less than optimum.


Keep the screens tight, the emulsion tough and move fast. Move all the screens to the end or the beginning of the press. Print with just enough pressure to punch the ink into the fibers of the shirt. Adding penetrant and retarder can help big time if it's dry and hot in your shop.

Keep screens flooded if stopping for more than a half a minute. If the press has a "front" position feature for the squeegees (flooded when stopped) then use it. Mist with water frequently but don't over mist or you'll get a puddled mess on the next print.

[ericheartsu]

Thanks EVO!

Those were my thoughts exactly as to why not flash. I'll report back in a day or two once this is set up and going. I'm actually thinking about printing it tomorrow.

[ericheartsu]

setting these up right now, will be printing in about 15 mins.

all screen info is the same, switched the smiling jacks to the sharper edge, to lay down not as much ink.

screens are in head 7, 8, and 9.

[ericheartsu]

40 shirts in, and so far so good. having a slew of other problems, but zombie skin doesn't seem to be one of them.

[alan802]

Well, what's the verdict?  Did everything go smoothly or were there issues?

[ericheartsu]

Sorry we finished towards the end of the day, so i got caught in answering emails.

All the tips that everyone gave us were super helpful! No zombie skin. Loading to the front of the screen helped a ton, and making sure the screens were back to back was what i feel the biggest help.

This order was just a bit over 100pcs. The one issue we have, particularly for this client, is making sure there is no lint blocking the prints. The blue and the pink were just fine, but because the yellow is such a wide, open space, we were having to stop every 4-5 prints to clean out lint.

These were being printed on next level 3600 tees, we had a freshly adhesived lint/roller screen up, and eventually reverted to even using a lint roller right after loading the tees.

again thank you everyone for chiming in with their help!