Ghosting/Image transfer on same side of sheet

We are running into an issue where the image on the one side of the sheet with mostly white space will remove magenta from the other side of the sheet with heavy ink coverage. It seems this is only happening in the magenta unit. This also happens when the front of the sheet has a two page spread, but only an image on the one side, then the back of the sheet has a two page full bleed image, the full bleed image is lighter one side then the other. I have attached a sample to kind of show what we are experiencing.

Image from the lead edge of the sheet is pulling ink from the trailing edge of the sheet. So if there 4"x4" image on the ledge edge of the sheet and a full tint on the trailing edge, there is 4" wide area on the tint that is lighter. Yes it looks like it is mechanical ghosting, but only shows up in the magenta on two presses, a CD 102 and SM 102.
 

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We are running into an issue where the image on the one side of the sheet with mostly white space will remove magenta from the other side of the sheet with heavy ink coverage. It seems this is only happening in the magenta unit. This also happens when the front of the sheet has a two page spread, but only an image on the one side, then the back of the sheet has a two page full bleed image, the full bleed image is lighter one side then the other. I have attached a sample to kind of show what we are experiencing.

Is it just me? I can't understand the description of the problem. The images aren't clear either.
 
Looks like mechanical ghosting or ink starvation in the image possibly due to some of the following conditions, poor image layout, improperly set ink rollers or dampening rollers, poorly set ink form rollers to distributors, Running too much water on the plate, improper roller durometers, Ink oscillators not working properly, too much water on the sheet from a unit prior to the problem colour and a whole host of other causes.
 
If I understand the pictures (which is not entirely clear in the explanation) it looks like mechanical ghosting.

@smeyer 1984 - is the lighter image on the opposite side of the sheet? If so, it is mechanical ghosting which is awfully tricky to deal with.
 
Image from the lead edge of the sheet is pulling ink from the trailing edge of the sheet. So if there 4"x4" image on the ledge edge of the sheet and a full tint on the trailing edge, there is 4" wide area on the tint that is lighter. Yes it looks like it is mechanical ghosting, but only shows up in the magenta on two presses, a CD 102 and SM 102.
 
Looks like mechanical ghosting or ink starvation in the image possibly due to some of the following conditions, poor image layout, improperly set ink rollers or dampening rollers, poorly set ink form rollers to distributors, Running too much water on the plate, improper roller durometers, Ink oscillators not working properly, too much water on the sheet from a unit prior to the problem colour and a whole host of other causes.

Agreed!

@smeyer1984 from my side, I think you should reduce dampening solution (can add some more alcohol if need), change better ink and blanket. You also possible make 1 or 2 of inking form rollers ocsilating a bit...

Hope you feedback when your problem is over.
 
Confirm with the press operator he has decontaminated the rollers recently.
You can get mech ghosts in areas you shouldn't when the rollers are glazed with calcium.
 
The photo is not clear enough to determine the cause, but I have seen similar problems particularly on small offset where upper image appears as a ghost image in a large solid or halftone below. In these cases, it was ink depletion on the form rollers. The ink on the form rollers has not sufficiently replenished when it rolls over the lower image therefore the ghost.

Solutions:

1. If possible, change the layout so the solids will run side-by-side.
2. Run them in two passes or two color press if the layout will allow it.
3. If the press will do it, sometimes using an alternate sheet feed feature is helpful.
I am not familiar with you press models, but three or more form rollers should do the trick. Other suggestions such as ink tac, glazed rollers, fountain solution, pressures between rollers or between forms and plate could be checked as they all affect ink transfer.

Tomtech
 
looks like an ink starvation ghost to me. If all your roller settings are known to be correct you may want to try a couple of things. My first try would be to be sure that your Z roller (bridge roller) is set correctly and oscillating. My next try would be to allow the first 3 form rollers (counting from the form roller closest to the dampener) to move side to side in their cups. Stay away from the last form roller from oscillating as it has the potential to show up on the sheet as a scumming issue. If they have no result then change your layout if possible to run them images horizontally. You could also image your plates with the required "ghostbuster" takeoffs. Last but not least you could always cock the entire form on the sheet by at least a half inch or so. This of course will probably mean using a larger sheet of paper and cause additional labor in finishing but its a pretty sure bet to work as long as its in the budget. Good luck and let us know how you make out.
 
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