Pigment Particles in Discharge

[squeegee]

Hey everyone,
We are having a perplexing problem, at least I am perplexed...having trouble getting minute particles of pigment to fully disolve, this example was a khaki color we formulated with white pigment, flo blue, flo yellow, and flo pink pigments + dis base.  Throughout the run on a few shirts we would see the problem as in the pic, only from the flo pigments (yellow, blue, pink), not the white.  There was no way to fix the misprints and it was hard as hell to see the particles until they come out of the dryer.

--The ink was mixed with a drill and a mixer blade, we mixed it very very well.  My thought is that dry pigment residue off the squirt bottles we use could be the culprit, or dried dis base residue on the gallon bucket of base could be the problem, but I'm not really sure. 

Anyway figured someone might have more experience on this, so any suggestions would be greatly appreciated.  My lead printer wants to strain every color with screen mesh, I want to find a better solution if possible.

[brandon]

Straining will help that for sure. But how are you mixing your discharge inks? We almost never have that problem if they are mixed correctly. We do pigments first, the base next, mix, then fixer, mix, then agent. Mix. Then water for the final touch. Mix again. And you can throw printgen in there as well if needed. But we are in a pretty cold environment most of the year so we don't have to worry about the ink drying in the cups/screens as much as others I assume. So maybe it is a mixing issue? I do know when we first started out with discharge years ago and we just put everything in the cup and mixed it got clumpy and this happened every time.

[ebscreen]

That right there is the biggest PITA in dealing with waterbased.

It is suggested to filter your inks through a low mesh after mixing and before use.
Also a PITA.

What we've found is that putting the pigments in small squeeze bottles reduces the air space
and hence drying out that causes these un-dis-solvable particles. Also, check the nozzles
on the squeeze bottles and wipe them off before and after formulating.

Also, a super high speed drill and a jiffy mixer goes great lengths to solving this. When our old
corded drill finally crap the bed we got a new one in and that thing is ridiculously fast. We haven't
had the particle problem since, and we don't filter any more.

[brandon]

What we've found is that putting the pigments in small squeeze bottles reduces the air space
and hence drying out that causes these un-dis-solvable particles. Also, check the nozzles
on the squeeze bottles and wipe them off before and after formulating.

Yup, same here. Go to a restaurant supply store. Like a dollar for the bottle and top

[DanK]

All good advice above.  We use squeeze ketchup style bottles with tops on them too, high speed drill with a jiffy mixer, we also filter using 80 mesh I believe (maybe 110 but I am pretty sure it's 80) after the mix.

The one thing not mentioned that we also do to combat this problem, is mix the discharge agent with some warm water, separate from the ink and right before you add it to the ink mix...  Just a little water with the right amount of discharge, again warm (not hot), swirl it or stir it for a couple minutes just to get it to start dissolving, then mix it into the rest of your ink batch and you're good to go...  It seems minor, but it really helps.

[Screened Gear]

Squeegee,

You must really be behind on your jobs. Its 2011!!!

Are you talking about the pink spot on the white??? I maybe missing somthing.

[squeegee]

Yep, that pink spot is a piece of pigment that wouldn't/didn't dissolve.  The one thing mentioned we do not have is the very high speed drill, ours is no slouch but I'm sure I can find one that does more RPM's.  Really just don't want to go through the screen mesh filtering thing if possible because that will cost more time if done on every color, gotta say we don't see this problem on stronger colors, it's always on lights or pastels that have small quantities of very contrasting pigments in the mix.  We don't see the problem at all with RFU sericol, but I like some of the colors we get with pigments a lot better, so we're going to deal with it.

I'm going on a hunt tomorrow for a "ridiculous fast" drill and will try some warm water to dissolve activator prior to mixing, already have a set of larger squeeze bottles en route, so I'll transfer pigment to those when they come in.

I think the problem in part is lack of good house keeping, keep the pigment bottles clean and the dry pigment debris will not get in the ink, though my printer/inkman is having a hard time with that for some reason 

Thanks for the tips everyone.

[ebscreen]

Certain pigments are worse than others. That color right there looks like the one we had the most trouble with, I want to say flo. red or thereabouts. And yeah, I've never seen a drill this fast before.

[squeegee]

Do know off hand what brand/where you got it?

[ebscreen]

PowerGlide, Ace Hardware. I figured you don't need a Dewalt for mixing ink, but ended
up pleasantly surprised. It's blue and orange if they sell it under a different brand.

[sweetts]

I think this can be explained here 

Quantum Superposition - What the Bleep excerpt

though it is based on photons I do believe that ink particles can and are able of achieving a superposition state, at least in my shop it happens. The ink particle is on the screen and yet at the same time on my thumb that then is on the neck of the shirt, thank god quantum physics explained it for me.  lol

[jsheridan]

  My thought is that dry pigment residue off the squirt bottles we use could be the culprit,

There is your answer.
Black and red are the worst culprits.

I also use the small squeeze bottles to minimize air exposure.