PM74 ink piling

[Alistair Tinsley]

I have a problem with ink piling on the PM 74.
It is more a problem on the drive side of the machine and in back end of the sheet.
Have changed damping solution and cleaned machine but still a problem especially on that one side.
Nothing else has changed from the past .
Have checked damping rollers and they all seem good.
Have to stop every few hundred sheets a clean.
Printing black on white sheet on one unit
Any suggestions
Thank you in advance

 

[junker1984]

Have you examined the condition of the journal boxes (the containment of the roller journal bearings)? I’d focus on 1st inking form and the dampener rollers GS.

 

[Alistair Tinsley]

Would a ceased bearing cause piling as I've checked these on the damping rollers and they seem fine
You saying the inking form roller pressure to plate?
I've check this and is set to recommended pressure.
Forgive my stupidity but what is gs short for?
I am relatively new to these machines
Thanks sgain

 

[junker1984]

Gear Side. But inspect closely on the side that is giving you most issue. Just thinking you may want to examine closely the “bearing holders” to see if yours getting excessive bouncing under production.

 

[Alistair Tinsley]

Hi Junker
I changed to the other unit and I am getting it there as well.
Have washed down and opened new tin of ink but still doing it and even on same side of machine.
Strange.What should I try next?
Thank you for help

 

[Raf77]

Paper?

 

[junker1984]

Odd set of circumstances, I'd agree with Raf and next look into chemistry. Post pics.

 

[Alistair Tinsley]

Going to strip all rollers out again and check.

 

[Steve F]

Post some pictures of the sheet, blanket and plate, close ups to show the problem.
Press room good temperature? It has been 'kin cold recently...
Pan roller nut tightened up on the DS?, they have been known to loosen up a bit.

Steve

 

[Alistair Tinsley]

Hi all.
Think have got problem sorted.
Machine has been running all morning without the issue appearing.
I am not the operator on the machine so was taking the guys word for it he had checked everything which of course was incorrect.
I stripped rollers out again and found inking roller No 1 (blue) had swelling on one side making it lumpy which I reckon was causing shatter then the result piling.It was ever so little but noticable on white sheets after 7/8000 sheets or so.
Everything seems good now that the roller is replaced .
The second unit had issue with paper sheet under blanket breaking up.Same problem ( shatter).
Thanks for help guys

Appreciated

 

[junker1984]

Great job! Now get to work