banding on sx102

hi new to this forum, currently running a heidelberg sx 102 8 colour perfecter. im getting banding on the 6th unit (cyan) only visible on certain jobs with screens. any ideas cheers

 

Could be a number of problems, roller settings, roller bearings, packing

 

checked the roller settings and they are ok, changed the blanket and packing but no change

 

Are the form rollers oscillating or fixed

 

oscillating because of the nature of some of the jobs we get a lot of ghosting

 

Have you tried cutting the oscillation down on some of the form rollers, i would also check the all the roller bearers , do you get any tinting on the blanket.

 

tbh the oscillation is minimal on a couple of the form rollers, will have to check the bearers. not noticed any tinting.

 

Does the sx use the airblade technology on the dampers

 

To eliminate the form rollers you could remove or back them off one at a time and see if you can pinpoint the problem.

 

im not sure tbh, not very familiar with this technology. its the basic model if that helps

 

If it does you would have black vent controls, that control the air that blows on to th metering roller.

 

it is old technology on that press, rollers perfecter and everything.

 

oh sorry it does have the vent controls, wasn't sure what they were called

 

Does adjusting them make any difference

 

Also it dont have to be the form rollers alone that cause that sort of banding, it could be transfered from further up the roller train. Thats why i said check all your roller bearers.

 

What ink are you using

 

i will back each form roller off to eliminate each one on my next shift, tbh i haven't used the air blade technology not to familiar with it. we are using saphira bio extreme ink

 

You also try adding a bit of reducer to the cyan, to reduce the tack, but be carefull not to add to much if you are printing tints.

 

ok thanks will try that. would you advise to open some of the valves for the air blades. what type of jobs are they designed to be used for?

 

I would advise opening them a little where you are running the tints, but just play around with the settings to see if you can get any better results, it just helps you control the water better, on certain parts of the plate.