Emulsion for Discharge

[Sbrem]

OK, I know this has been discussed to death, but I'm nutso busy like the rest of us and don't have time to search. We had a discharge job breakdown yesterday, halftone dots falling off the mesh, the emulsion was Autotype 8000. Our screen guy was told that this was the one used by Liquid Blue, who does very nice work of course, and are extremely well versed. Well, never listen to a salesman, always talk to the users, like our board members here. We do very little discharge, and this is the first time something like this has happened. I can think of a hundred reasons why, but I'd rather hear something short and sweet from the folks who do it all the time. So, favorite emulsion for Discharge? Thanks in advance...

Steve

[Colin]

Saati PHU is great with or without diazo.

We use Murakami T9 with Diazo.  We also have an iImage and Starlight.

I forgot what exposure unit you have.... Some of the water resistant emulsions will get tacky on hot glass.

The Saati does not which is why I used it for 4 years with a nuarc 3140.

[mimosatexas]

Still using sp1400 for everything

[zanegun08]

discharge job breakdown yesterday, halftone dots falling off the mesh, the emulsion was Autotype 8000.

It possibly isn't the emulsion that is the cuplrit.  Autotype says that is resistant to both waterbase and solvent emulsions.

We had that same issue for a while, turns out we were trying to image screens to soon without them being fully dry before exposing.

Also adding a post exposure, or if it is a large run a reclaimable hardener (don't get me started on how my guys were using an unreclaimable hardener for years by accident and wondering why the screens were so hard to reclaim)

It seems that the emulsion should be fine for discharge, may be something else in your process causing the breakdown.

Reclaim / Degrease / Drying Time / Exposure Time / Post Exposure, lots of places that could go wrong, don't just switch emulsions if the price is right.

We use Kiwo MultiTex for everything besides our number screens.  Post expose on water base jobs, and reclaimable hardener on large water base jobs and since figuring out our screens weren't totally cure before imaging we've had no issues.  Ended up building a new room and moving the coater into a better climate controlled area to speed up the process of drying.

[SI]

Saati PHU is great with or without diazo.

We use Murakami T9 with Diazo.  We also have an iImage and Starlight.

The Saati does not which is why I used it for 4 years with a nuarc 3140.

Saati PHU was working great for me, over 1000 shirts with nothing more than a post exposure, but lately it has been breaking down before 100 shirts.  Over multiple gallons so not just a bad gallon, and I know of one other person who is having issues as well.  I will most likely be switching back to SP-1400 until I can figure out why the emulsion is breaking down, nothing has changed, LED exposure so no wear and tear of a lamp.  Humidity, coating technique all the same as well.  I had a gallon of T9 but went through it before we got a discharge job, how does it compare to the PHU?

[merchmonster]

Still using sp1400 for everything

We use murakami sp1400 for discharge no issues with breakdown. Cheap too, thirty something bucks a gallon. Also the guys down the street at forward which is a water base shop use this stuff also

[Orion]

Kiwo Multi Tex here, it's a PP and has worked well for me in less than optimum, screen room environmental conditions. A little spritz of Kiwo WR hardener brushed in and you are good to go.

I would add that less eom, without sacrificing resolutions, (i.e. sawtooth) will help out with longevity of your  stencil.

[Sbrem]

discharge job breakdown yesterday, halftone dots falling off the mesh, the emulsion was Autotype 8000.

It possibly isn't the emulsion that is the cuplrit.  Autotype says that is resistant to both waterbase and solvent emulsions.

We had that same issue for a while, turns out we were trying to image screens to soon without them being fully dry before exposing.

Also adding a post exposure, or if it is a large run a reclaimable hardener (don't get me started on how my guys were using an unreclaimable hardener for years by accident and wondering why the screens were so hard to reclaim)

It seems that the emulsion should be fine for discharge, may be something else in your process causing the breakdown.

Reclaim / Degrease / Drying Time / Exposure Time / Post Exposure, lots of places that could go wrong, don't just switch emulsions if the price is right.

We use Kiwo MultiTex for everything besides our number screens.  Post expose on water base jobs, and reclaimable hardener on large water base jobs and since figuring out our screens weren't totally cure before imaging we've had no issues.  Ended up building a new room and moving the coater into a better climate controlled area to speed up the process of drying.

I haven't seen a reclaimable hardener, who makes that?

Steve

[mimosatexas]

Murakami has two hardener. One is easily reclaim able, one isnt.

[Sbrem]

as always, this is the place to ask a question and get a straight answer. Thanks all, we appreciate it. Hope you're all having a good one.

Steve

[screenprintguy]

Chromaline Chroma Tech WR has been our emulsion for the past several months. Zero break down issues with discharge and wb. We are switching back to Murikami T9, both are awesome. No need for a diazo unless you want to slow down the exposure time. I've put T9 back in the mix this week, 1/1 sharp edge coating with the UniKoter. Super fast exposures, post expose squeegee side toward the light, that stuff will NOT break down unless maybe you didn't let them dry good after coating. I'm a stickler for letting freshly coated screens dry over night. Either are awesome if you don't like to mess around with diazo emulsion, but you can add it to either. For instance on exposure times. 330 s thread, 305 T mesh, 280 T mesh, fully crosslink in ONE second on the Starlight. No glass keep in mind we are CTS. Our longest exposure is 7 seconds on a yellow mesh 110, which we don't have many of those in the mix. I did video for Chromaline holding 1% halftone dots with the ChromaTech wr on the 305 exposed in 1 second and beat the crap out of the screen with a 2000 psi power washer on the squeegee side to proove. Same goes for the T9. Both are great!

[ericheartsu]

Saati PHU is great with or without diazo.

We use Murakami T9 with Diazo.  We also have an iImage and Starlight.

The Saati does not which is why I used it for 4 years with a nuarc 3140.

Saati PHU was working great for me, over 1000 shirts with nothing more than a post exposure, but lately it has been breaking down before 100 shirts.  Over multiple gallons so not just a bad gallon, and I know of one other person who is having issues as well.  I will most likely be switching back to SP-1400 until I can figure out why the emulsion is breaking down, nothing has changed, LED exposure so no wear and tear of a lamp.  Humidity, coating technique all the same as well.  I had a gallon of T9 but went through it before we got a discharge job, how does it compare to the PHU?

Have you been post exposing? we set our screens in the sun for like 20 mins, and ZERO breakdown.

[ABuffington]

We all use the term water base inks in describing a lot of the inks that are out there.  In reality only water base and discharge fall into true water base inks.  High solid acrylics are co-solvent inks.  They use water and solvents in the mix.  Emulsions like to be solvent or water resistant, so a co solvent ink needs an emulsion that resists both water and solvents.  The new high solids inks will open new markets where compliance to incredibly tight testing tolerances is needed, plus the hand is hard to beat.  Sometimes I wish I still had a press!

Al

[Sbrem]

Saati PHU is great with or without diazo.

We use Murakami T9 with Diazo.  We also have an iImage and Starlight.

The Saati does not which is why I used it for 4 years with a nuarc 3140.

Saati PHU was working great for me, over 1000 shirts with nothing more than a post exposure, but lately it has been breaking down before 100 shirts.  Over multiple gallons so not just a bad gallon, and I know of one other person who is having issues as well.  I will most likely be switching back to SP-1400 until I can figure out why the emulsion is breaking down, nothing has changed, LED exposure so no wear and tear of a lamp.  Humidity, coating technique all the same as well.  I had a gallon of T9 but went through it before we got a discharge job, how does it compare to the PHU?

Have you been post exposing? we set our screens in the sun for like 20 mins, and ZERO breakdown.

In further conversation, it may be that someone (not me, but I"ll take the heat anyway) did not post expose. We are going to tighten up some of those practices so as to not have them pop up again. I've also been interested in the HSA inks, but the amount impressions for a one color print puts me off, as our markets couldn't absorb that, but things are always changing, especially here, so I'll keep following those trends as well.

Steve

[ABuffington]

The key to success with T9 is to maximize the exposure time for complete cross linking, then post expose in exposure unit or put in the sun (in summer) squeegee side towards the sun.  We also have a high res dual cure: Photocure WSR that can print all inks, no hardeners.