inconsistent hoodie prints

[jvanick]

Today was a new one on us...

ran a batch of Gildan hoodies, 156 mesh, 80 durometer wilflex quick white, no problems at all...  from the first to the last, every print was near perfect.

then, started running a batch of Hanes F260 "printproxp" hoodies.. (in red if that matters at all)...

same ink, literally same squeegee settings (nearly vertical on the chopper head on the javelin, speed, pressure, etc.  We couldn't get a consistent print no matter what we tried.

some would run ok, some we were having problems clearing the screen.. even when trying to make a few of them bulletproof, we couldn't get a consistent laydown of ink.

Thoughts, suggestions are all welcome.  I gave up on the order after 6 failures (and a ton more of just moving those failures around to try to get a consistent print)

I need to revisit this job sometime this week, but it just doesn't make sense at all.

[Lizard]

The Hanes should print easier, mostly cotton.  But on sweats I would use 80 or 110 mesh and single stroke only very slow. Double stroking on sweats causes all kinds of issues.

[aauusa]

I know this May not be the issue but make sure off contact is good and the tax on the platen is strong. Most times this is caused for me with lack of tac. Watch the screen when you print to see if the screen clears and separates from the screen after the squeegee passes.


I have a freedom with the v squeegee and we put our whit in 230 minimum. You should not need a lower mesh to get better coverage. Find the root of the problem rather than lowering the mesh.

[jvanick]

no problem on the spray tack.. in fact if anything there's TOO much web tac now.

I tried off contact varying from what I use for my tshirts, (3/16"?) to adding an 1/8" to adding a whole 1/4"... on the good ones.. I'm getting a full clear, on the 'bad' ones.. it looks like a waffle pattern on the screen...

I tried adding so much pressure that the squeegee was practically bending over... just to see what happens... it's the weirdest thing I've seen.

I'm wondering if it's time to try some triple-durometer squeegee blades...  (or maybe a smiling jack or something different)?

[Printficient]

no problem on the spray tack.. in fact if anything there's TOO much web tac now.

I tried off contact varying from what I use for my tshirts, (3/16"?) to adding an 1/8" to adding a whole 1/4"... on the good ones.. I'm getting a full clear, on the 'bad' ones.. it looks like a waffle pattern on the screen...

I tried adding so much pressure that the squeegee was practically bending over... just to see what happens... it's the weirdest thing I've seen.

I'm wondering if it's time to try some triple-durometer squeegee blades...  (or maybe a smiling jack or something different)?

I would highly recommend triples for that press.  Smiling Jacks do not work on "V" squeegee set ups.  I sounds like to me the load of ink behind the squeegee fluctuated.  I have a couple of questions though.  Give me a call.  Sonny.  678-412-1395   I carry Pleiger Triples for $1.35 per inch.

[Colin]

Double check the weave of your sweatshirts.....

We all forget that the weave of the garment is also partially responsible for good ink laydown.  If the weave is very open and loose (seen a lot of sweats this way) then it will be almost impossible to achieve even a mediocre print.

Let us know how you worked it out!

[inkman996]

Hate to do it but when we run into nasty fleece that will not cooperate I usually add a little curable reducer to the white. Printability gets a lot better but opacity suffers a little.

[jvanick]

I had to run out of town for my day job... so won't be revisiting this till later in the week.  I'll keep ya'll posted tho as to what our end-resolution is.

I'm going to try both a double bevel and some triple durometer blades on the chopper head, as well as triple durometer blades on one of the vsqueegee heads.. I have a bunch of 'testers' now, so hopefully I'll get to the bottom of it.

worse case, it's only 50 shirts, we'll run them on the manual...

-J

[jvanick]

So we got through the 50 shirts last week, and here's what the end results were:

70 durometer double-bevel in the chopper head.
medium speed flood and print strokes
squeegee pressure was minimal, just enough to 'kiss' the shirts
156 mesh screen
Wilflex Performance White with ~3%Viscosity Buster added (I think this made a huge deal)... apparently you're not supposed

First pass cleared 'most' of the ink from the screen, 2nd pass (after the flash), took care of the rest... not 100% sure why the first pass wasn't clearing fully (probably due to the open weave of the shirts), but this is what got us the best final print...

ended up having some troubles on 2 of the platens, but found that they were out by less than 1/32"... dialed those back in, and everything ended up perfect.

end observations...

double bevel squeegee's rock...
less pressure makes more of a difference than I'd think...
press alignment REALLY matters...  I might need to rig something with dial indicators for leveling the platens... with the vsqueegees, we never had an issue until things got really out of whack.

[Doug S]

press alignment REALLY matters...  I might need to rig something with dial indicators for leveling the platens...

That is something that I'm looking into as well.  Using the coin method on the pallets works but not with perfection.

[jvanick]

this is our current 'alignment jig' ... it works pretty well, but life would be way easier if we could see all 4 corners of the platen at the same time.

considering rigging something up like this tho with 4 harbor-freight dial indicators...



-J

[Inkworks]

Level/parallel to the screen is one thing, level/parallel to the stroke of the squeegee/floodbar is something else. We level platens to the floodbar stroke with no screen in the head.

[jvanick]

so now you've got me curious...

if the screen is level to the track that the squeegee/floodbar carriage rides in, shouldn't levelling the platens to the screen work?

also... since you have individual adjustment on each side of the squeegee/floodbar choppers, how do you make sure that you're doing a repeatable leveling?

-J

[Inkworks]

so now you've got me curious...

if the screen is level to the track that the squeegee/floodbar carriage rides in, shouldn't levelling the platens to the screen work?

Yes. But why not skip the middle man, you can end up being out a bit on the print rail to screen, then a bit out between the screen and platen, and then end up out more than a bit overall. The stack-up of tolerances can add up.

also... since you have individual adjustment on each side of the squeegee/floodbar choppers, how do you make sure that you're doing a repeatable leveling?

-J

That's a million dollar question, for us, our press is almost perfectly level, so we use a level on the floodbar side to side, then pull a safety cord and move the floodbar back and forth measuring between it and the platen. My main point is that it doesn't matter if your platen is level to the screen if they aren't level to the stroke of the print rail.

I had a press operator level a vacuum bed on a Cameo using a bubble level, then set the off contact from there, and the press wouldn't print worth a crap, we couldn't figure it out until I found out how he had done it and looked, the stroke of the press was out more than 3/16" from level from one corner to the other, we leveled the bed to the stroke, set off contact from there and were back in business. the press could have been on a 15degree angle and aside from the ink running one way or another, if the bed is parallel to the print stroke it'll print perfectly.

that's just what works for us, I'm not sure how the pro's do it.....