Ink not printing?

[3Deep]

Bear with me here fellers got a crazy problem and will try to explain, last Friday we are printing a simple two color print purple on a white base easy job so I thought. Screens are 137 mesh ct so we're doing 78 pcs  I P/F/P the underbase carefully not to over cook, we get down to the last for shirts and the purple starts to print very light pastel looking.  No problem, I wipe the bottom of the screen and hit it again same thing, ok I wipe it again and flash the already pastel purple print and reprint same thing, so I skip that shirt and go onto the next and yes it prints the pastel purple again only on one side, now mine you I've run all the shirts the same way except for these 4 want print correct.  I ended up taking a small soft squeegee about 60 duro and hand printing that spot on the press and it covered fine, after I did the run I went back and printed that color by itself with out the underbase and it printed fine.  I know it had some thing to with the underbase but why these four shirts and not the rest? any of you had this happen and figured how the cause.

darryl

[ericheartsu]

Bear with me here fellers got a crazy problem and will try to explain, last Friday we are printing a simple two color print purple on a white base easy job so I thought. Screens are 137 mesh ct so we're doing 78 pcs  I P/F/P the underbase carefully not to over cook, we get down to the last for shirts and the purple starts to print very light pastel looking.  No problem, I wipe the bottom of the screen and hit it again same thing, ok I wipe it again and flash the already pastel purple print and reprint same thing, so I skip that shirt and go onto the next and yes it prints the pastel purple again only on one side, now mine you I've run all the shirts the same way except for these 4 want print correct.  I ended up taking a small soft squeegee about 60 duro and hand printing that spot on the press and it covered fine, after I did the run I went back and printed that color by itself with out the underbase and it printed fine.  I know it had some thing to with the underbase but why these four shirts and not the rest? any of you had this happen and figured how the cause.

darryl

could the base be to hot that it was starting to cure the purple? and maybe it was blocking up the screen?

[ScreenPrinter123]

Did the underbase maybe not fully gel?  That could cause what you are describing.  This happened to us once when our quartz flash decided to just stop coming on for the set time and it took me a little while to figure it out until I touched the underbase with my finger.  We reset the flash and we were back in business.

[ebscreen]

Yep, that's happened to us before too.

[Frog]

But, if I understand what he says, these same shirts printed fine when the purple was put down manually.  Wouldn't the same blending with the still-wet white still occur?

[blue moon]

ubase not cured!
could have been a draft or bad bulb or something else. . .

pierre

[ebscreen]

But, if I understand what he says, these same shirts printed fine when the purple was put down manually.  Wouldn't the same blending with the still-wet white still occur?

My thoughts too, but stranger things have happened. This is screen printing, after all.

[bimmridder]

Let me toss out another possibility. Uneven ink deposit on underbase?

[Frog]

Let me toss out another possibility. Uneven ink deposit on underbase?

On only four shirts?

[3Deep]

I have no answer, very weird how it did that on the last four shirts, I was thinking the same thing underbase not flashed good, also underbase over flashed, but when I use that soft squeegee and hand printed it, it printed fine @ebscreen your right chit happens and I might never know why it did what it did.  Heck you can push a rock thru 137 mesh LOL

[bimmridder]

Didn't read close enough. I saw the "hand printing " part and assumed.....

[Homer]

D - did one of the choppers blow out on the squeegie? loosing all pressure on that one side?

[mimosatexas]

have you successfully printed using the same parameters but a different screen in that head since it happened?

[3Deep]

I didn't think about a chopper giving up the ghost, but I don't think that's it , stranger things have happen before.

[rmonks]

The guy I sold my Javelin to told me to come by his shop one day to look at a modification he had made to his Flashback. What he had done was take a thin sheet of heat resistant material like bakelite or asbestos this was about the thickness of a nickel and the size of the area over the reflectors on the back side of the flash tubes and this solved the problem of the ink curing in the screens.