Discharge Woes

[ABuffington]

SP-1400 is an economical diazo emulsion for all ink systems.  Being a diazo emulsion it needs a little longer exposure.  If you have high volume screen production go with HVP plus diazo.  It is worth noting you can add 8 grams per gallon, or double it to 16 grams per gallon for added strength.  On 5k+ systems this often means you will not need a hardener.  We also have 2 new emulsions, Murakami T3, no hardener needed for dc and wb and Murakami TSR for High Solid Acrylics as well as dc and wb.  Too many are referring to high solids acrylics as a water base ink.  It is a co-solvent ink, so it requires different emulsions.  For discharge however a good exposure works wonders on either SP-1400 or HVP.

Happy New Year everyone, lets rock 2015 and all have our best year ever.

Al

[sqslabs]

I know it is not exactly close to you but these guys sell the 150LX and 180LX by the yard.- www.nwgraphic.com I have some too I could send you if you want. To each their own, but the only time we will use the 150LX for discharge is on hoodies. I know there is minimal difference but we found for us the 180S or 180LX leave a much softer hand.


You got much more intelligent responses here compared to my mumblings yesterday!  ;D

I didn't see it on their website, but will give them a call.  Any chance they sell S-Mesh by the yard in counts other than what River City carries?

And your "mumblings" were some of the best info I've received on the subject!  I even took notes!!   ;D

I'm sure all of these suggestions are valid but we do not use special mesh or squeegees. Could the Charleston climate which year round is either damp or humid.

Funny you should say that. I printed discharge without these issues for years using 158 statics at 12-15N with a 70 duro blade on a press without pressure adjustment or the ability to adjust off contact.  Maybe its time to get back to basics.  On the subject of humidity, we certainly aren't lacking that in Fort Lauderdale.  :o

[ABuffington]

You can order any of our meshes through our distributors and have it dropped shipped to your location.  This helps the local distributor see demand so they will stock it.  So many meshes, it's hard for a distributor to stock all of it.  LX Mesh is often not stocked by dealers, but it works well.

A couple of print techniques for discharge:

1. Try using a slightly thicker stencil. This helps hold more ink in the image area to transfer. 1 additional coat can do wonders, as can face coating print side. For durability face coating squeegee side as well and upping the exposure time also helps.
2. Try on contact printing.  A flooded screen on contact will start to wick into the fabric before the squeegee even makes the pass and the fabric will have time to soak up more discharge.
3. I liked a worn 70 durometer with a rounded edge at 5 degree more angle.  I would often save the worn plastisol base plate squeegee that couldn't cut plastisol anymore and use it for discharge and wb.  Watch for nicks though, they will affect the print.
4. Angle:  Most shops never change angle of squeegee, yet this is crucial for discharge IMO.  Bright color comes from loading the shirt fabric.  A fast moving vertical squeegee used for plastiosl overprints is nowhere near the quality of a rounded edge squeegee with a slightly slower squeegee speed with more angle.  Go ahead and crush the print with plastisol squeegee settings to drive it in, but this is best for short runs.  Long runs benefit from more angle and ever so slightly slower squeegee speed.  Slowing down the flood so it completes it's pass just as the head drops or pallets raise also helps fill the image area with a more complete load of ink.  You can still print fast with just slight adjustments of speed.
5. Localize your inks.  By that I mean use ink dams made of tape on all four sides of the squeegee path.  This limits the inks exposure to air which can lower the discharge effect and cause color shifts.  Run with a full blade of ink at all times, also keeps activators in balance with the bases, controls color well.  We had ink personnel who added a drop of ink about every ten to twenty prints who would simply walk back and forth over three presses to maintain ink levels.  Localizing ink also prevents dark ink ribbons in the open areas of the print when ink is pushed back into the print area after sitting exposed to the air.
6. Pillow flood higher mesh counts so you can't see the image.  On lower mesh counts with S mesh you may not want to pillow flood and leave a pile of ink on top of the image since it can drip through.  But for 180-225S it can help pop the color more.
7. If you see stripes in your print it is a mesh/shirt fabric interference pattern.  Consider going to a 22.5 degree bias stretch, or to the next S mesh count up or down.  Sometimes I have seen this with hard squeegees and too much squeegee pressure as well.
8. Put a flash in the last head.  This allows the unloader to catch pinholes that discharge faster than solid areas of discharge.
9. Use a black sharpie to cover discharge pinholes on black.
10. Only activate what the press can print in an hour.  We used master buckets of color for long runs.  keep a quart container by each color.  Activate a quart with pre-weighed activator in plastic cups with plastic wrap and a rubber band over them so it stays fresh.  When quart runs out, scoop out another quart, leave a 1/2 inch from top, add pre weighed activator, mix and add a drop every ten to 20 shirts.  We also set up hand pump dispensers zip tied to the press so it put a drop in every time it printed and a long tube into the activated quart  that sat in a welded cup holder on the head.  Takes some fine tuning to position the pump and locate it so it doesn't pump out on the image.  We only did this on 20k runs or higher.   

Perhaps the craziest thing we ever did was a run with large cookie trays of different fluo discharge colors and a bunch of different tires like small bike tires, car tires, all with crazy tread patterns.  Roll the tires in the inks then roll them randomly over spray tacked black shirts adhered to a clean floor.  3x3 set up of shirts on the floor to do nine at a time.  There are spray tacks for the shirt to floor as well as different spray tack on inside of shirt that keeps it all flat.  Some of the coolest prints were tires that didn't make it across and spun down on the shirt.  This idea came from a Hendrix song lyrics of 'tires tracks all across my back" and maybe a few beers.  The mess, is well a big mess.  When the trays are running out of inks you can take spatulas and brushes and fling the ink across the shirts as well.  Charlie Taublieb has tons of more cool effects with discharge if you can ever take one of his totally t shirt seminars at SGIA.

See you all at ISS for those coming.   

Al

[tonypep]

All good tips Al. We keep 50 duro sharp blades around they can do wonders. Medium to low tension. We now know how to stretch activated inks up to 10 hrs but have master color kitchen with about 80 colors kept in gallons and activate as needed with little waste. New color recipie books almost finished

[tonypep]

These were always fun. Found a way to keep the mess to a minimum using transfer paper

[Underbase37]

Ummm. Sweet info. Thanks...going out to the shed right now to get an old bike.

Murphy37

[ABuffington]

One more crazy trick we tried.  Wash the shirts in a washer.  Stop at spin cycle.  take Ketchup bottles and squirt multiple colors of discharge on them while they are in the machine. Start spin cycle.  Not recommended, but you can push a pencil in the lid to keep spin cycle on and spray some more.  Craziest looking shirts ever. with subtle tones and bright highlights if you spray at the very end of cycle.  Curing is a pain though, ten passes through the oven and we had a 20' gas oven with electric panels in and out.  We experimented with spininng them twice, which got a lot of water out of the shirts and made more vibrant areas.  Run many cycles afterword to avoid the wife confrontation however when her clothing gets fades marks all over.  The things I have put that poor woman through.

[sqslabs]

Wow, awesome posts Alan.  Thanks for taking the time to write all that up, it will definitely be going to good use in my shop.

As an update to my original post, I seem to have solved the issue one way or another.  I'm not exactly sure what exactly it was as there are so many variables involved, but I'm leaning toward an old batch of activator possibly being the culprit.  In any case, the following changes were made:

New batch of Matsui Discharge White
New batch of Matsui activator
Added 3% Rutland Penetrant
Added 3% Rutland Lubricant
Increased burn time by 85%!
Much more liberal use of hardner
Changed blade angle from 12 to 18/19
Increased pressure from 40 to 50psi
Moved pallets in toward the press
Moved image further down the pallet
Brought off contact a bit tighter to to .05, which feels pretty much like zero with a shirt on the pallet

These changes were all made on Monday and we ran discharge for two days straight without a hiccup, up to 200 pieces per run.  Thanks to everyone who wrote here and contacted me privately to help with the situation, it is GREATLY appreciated.  I can't thank you guys enough, this forum and its members are the freakin best.