Printmaster 1c impression getting weaker

[mattknows]

We have a single color Heidelberg Printmaster with almost 20m impressions. For a while now the impression has seemed to be getting weaker and weaker. No where in the book is this addressed, but the pressman thinks that there are springs that pull the blanket to impression cylinder during run (like on an ABDick) and that perhaps they are getting worn out. Is there such a set of springs, or is there another way to get the impression stronger again short of replacing said springs if indeed they exist? If not, is there something else we can look at to remedy this problem? Thank you.

 

[junker1984]

Never have I ever seen the springs you mention become weak to the point they affect squeeze. Are you sure you're not having an ink/water balance issue? Is the pressure problem consistent throughout the whole image? I'd suggest you first run a breakaway dry solid, starting with normal print pressure settings for the stock you're running and back off one line at a time to prove even breakaway.

 

[mattknows]

Can you be more specific about the "breakaway dry solid"? I'm not the pressman so I'm trying to relay your instructions to the pressman. Thanks.

 

[junker1984]

Ink up as normal, damps off, run a few sheets on impression at "normal" squeeze, stop press, back off impression one line, run a few more sheets at that squeeze, repeat procedure until you see the "breakaway" of the image. It's obviously best if you use a new blanket and check that your packing is to spec. I also highly suggest you spec out blanket height to bearer with a blanket packing gauge. All pertinent info is in your op manual.