I'm working first time an alcolor GTOZ. Took all the alcolor rollers away and put them back together trying to do it acording to manual. Only in my dreams it was easy. I can't get it to distibute water evenly in the plate, but my biggest problem is that i have a 3" water stripe coming from cylinder edges to the inside and that makes it impossible to print anything. So my question is:

1. Wrong adjustment at certain (or several) point of dampening unit? (ex. too much pressure between plate dampener and metering roller, etc)

2. Water pan and/or water form rollers are worn and need to be replaced?

3. Something else that i'm not considering?

All help very apreciated

Moe

Make sure your inking rollers are set to spec, that's just as important as the Alcolor train in keeping the plate clean

Hi,

Settings should be:-

Plate damper to matt chrome 4 to 5mm
Z roller to plate damper 3mm
Plate damper to plate 4mm
Pan roller to metering roller ... just remove water from ends and + 1/2 turn
Metering roller to plate damper 5mm

Regards.

Hello,

Checked ink form rollers and seem good.
Calibrated alcolor rollers acording to specs kindly given me and got closer to good result... but.......

Still get too much water at operator side of machine(2 or 3" from plate edge)

I uploaded a picture of my result. Hope you can see it.

There you can see how i've got a lot of water on edges, then scumming and then again too much water in the center of the page.(wierd, isn't it?)

I saw that water damp roller is a little "wider" at edges.(a very common efect in rubber rollers) Could that be the reason why i get more water there? Contamination in the rollers?

Another thing...
When calibrating the metering roller against the pan... i did it when press was operating and both ink and water rollers were on. But didn't lock the bolts made for secure the mechanism because when i do so, calibration goes wrong....Could that show pan roller worn?

Help! Help!

Thanks!!!

Attached Images

DSC04479 copy.jpg (298.0 KB, 25 views)

Hi,

If you can, just check if there is a crown in the center of the pan roller, it should be slightly bigger in the middle than the ends.
Locking the pan roller up should not alter the setting.
It looks like there is is a roller issue somewhere.
Take the rollers out and give them a clean by hand using a mild pummice abrasive like Jif bathroom cleaner and also use a strong plate cleaner on the matte chrome.

Regards.

Hi,

Took rollers out.
Pan roller seems to be equal in diameter(or ever a little bit shorter in the middle)

Tried to take plate damp roller out and could not do it. I loosen the bolt that holds it at OS and thats it... does not move nor to OS or to DS... Do i need to loosen something else or put it in certain position?

Thanks

Hi,

I would back the setting off between the plate damper and matte chrome by a couple of turns anticlockwise as probably the friction is not allowing it to move.
The roller should pull over to the operators side and lift out on the drive side.

You may have a problem with the pan roller dimensions.

Regards.

Hi,

Took rollers out. Good cleaning. Put them back together.... quite same problem. But this time i could see what i think to be the problem.

When i see the ink stripe water damp leaves in the plate(when calibrating), i see not an even line but a line that "grows" as it approaches the edge. same efect against distributor roller.

If i calibrate according to specs, it will only clean the inked plate where damp roller is wider(edges). I can add more contact between metering and damp but then i get too much water even if i put pan roller at minimum speed.

My best guess?

Damp roller needs to be replaced.
Does it sound like it could be?
I just don't want to ask for a $300(?) roller with out beeing sure.

Thanks again!

Hi,

From what you have described above it sounds like there is an issue with that roller. It sounds swollen at the ends.

Regards.

I had the same problem and forced to replace all rubber rollers. Problems now are kind of adjustment corrections. But in general now situation is near perfect.