Roland R202t Ob registration problems at the tail edge

Hi,

I'm having multiple problems with my two colour press. Mainly registration problems at the tail edge. I've just changed the gripper pads on the impression cylinder, changed the blankets but still have the same problem. i.e, the front edge registers upto 3/4 of the paper then the registration the starts to go off at the tail. The machine has been down for about 2 years but just trying to revive it. Any help will be appreciated

 

Well first see if your packing is the same in both units. You need a packing gauge not the little bar that came with the press. Packing needs to be .002 over the bear.

 

Thanks squid for your response. i'll do that and see if that will slove my problem

Cheers
Kipchumba

 

Afte you checked blanket and plate packings check your stock. Are you printing long or short grain? Is the stock new, is it conditioned to the pressroom? What about your ambient conditions - damp/dry? Check your pressrooms RH and temp.

 

Excessive blanket to impression cylinder pressure can cause misregister at the tail as can feed table brushes set too heavy at the tail of the sheet. Too much side guide pressure can also cause problems. Another cause could also be uneven head stops.

 

Check front lays, on most presses you can alter the left and right lays independently to fan the rear of the sheet out so the next units will fit after the paper has been stretched on the first impression, if this is the case the first unit will print wider at the back edge by 0.5-2mm depending on stock and grain direction and stock condition.

 

Check you swing arm grippers if the pads are worn the will cause this. Need more help contact me ps@igs-usa.com