Snow like effect on uncoated stock

[Kiran04]

Whenever I print on uncoated stocks, I seem to get this snow like effect on the image on just one side of the paper, like the toner did not quite stick to the entire images so there are small missing areas. Any ideas the cause and how to fix it?

 

[MarkD]

How old is the oil system. May need a good clean out to get rid of old contaminated oil. New tank, gut out the meter ***, new donor roll etc and fresh oil. A new heat roll won't go amiss either

 

[Kiran04]

We've done a whole oil system clean out a few months ago, so it's not super old. It only does this with uncoated stock, and only on one side. Coated stocks always print both sides just fine.

 

[CargoPantsMan]

Might need to adjust (usually lower) your transfer voltages for that stock.

 

[Kiran04]

Might need to adjust (usually lower) your transfer voltages for that stock.

That's something I don't know how to do. What does it entail?

 

[CargoPantsMan]

In your stock library -> media settings-> subsystem attributes for the stock you're running, edit the subsystem attributes and start decreasing the transfer voltage settings A and B for Sides 1 (first to print, not necessarily the file's page 1) and/or 2 (second to print). Sometimes, depending on weather or just finicky iGens, there's too much voltage for a certain stock. (More common with thick stocks, but not unheard of for text weights.)

 

[Kiran04]

That worked brilliantly. My guess is that the uncoated stock just retains residual voltage better than coated stock, or does not discharge as well. I brought the side 2 voltage down by 10 volts on either charge and the snow was gone.

 

[peels]

transfer voltage DOWN.

i have to do this with changing season into winter.... on our VERY light and porous offset paper.

However, go too low, and I start getting excessive static in the paper...

edit: i see it was solved, but ill leave comment for later.