Ink Build-up on Chrome Dampeners

[Kaoticor]

Press: Komori Lithrone 28
Fountain Solution: Flint Supreme 8168
Ink: Toyo 24/7

Description of Problem: Ink building up on chrome roller in dampening system (not the chrome water pan roller, rather, the chrome oscillator that bridges the form and the metering roller). Unit 4 is very bad, and a slight build-up is noticed on unit 1. Appears to be a ink/fountain solution chemistry, but we have ran both of these products for quite some time without any related problems. Has happened since 2-3 weeks ago. A picture is attached of problem.

Remedies tried:
Thorough flushing and hand cleaning of dampening system
Dampening filters changed
Hand cleaned and gummed (tried both buffing dry and sitting dry)
Used Comet cleaner lightly with gum aplication afterwards
Triple checked all pertinent roller settings
Checked soft roller duromoters and conical tape measurements
Swapped out metering rollers with non-problem units
Tried flushing and remixing fountain solutions at different pH and conductivity levels. (Currently 2800 conductivity at 4.3 pH, 3.8-4.5 recommended by Flint)
Adjusted a wide range of ratio settings (130-180)
Adjusted settings heavier and flooded damening system with solution (Ink build up still took place)
Different styles of washdowns (although we are always very thorough and consistent washing down and have been for years).

Additional notes: Again, we have used both the fountain solution and the ink for quite some time now and have not had any problems even closely related to what we are experiencing now.

I appreciate any and all feedback you might have and for taking the time.

[Servicetech]

My best suggestion would be to clean the heck out of the chrome roller.

You mentioned cleaning it lightly with comet, there is no need to be light on elbow grease, comet will not damage the roller. if the roller is contaminated with something stubborn, you'll have to scrub it off. Sometimes on the clean dry chrome roller, you can still see a slight difference in the color of the chrome, this is a contamination that ink will stick to.

Also you might try one of the stronger chrome roller cleaners out there, one of them that contains phosphoric acid. Or in rare cases I have used phosphoric acid by itself to clean the roller thoroughly.

[Cornishpastythighs]

Try some industrial cleaner with Phosphoric acid as Servicetech suggested, we have had some success with this for exactly the same issue on our 40" Komori. These are only bandaid measures and do not eliminate the root cause of the issue. I believe this to be an ink issue combined with the Komori dampening system design. As you cannot change the design I would suggest working with your ink company or maybe even trying another manufacturers ink to see if you get some improvement. We have tried every chrome roller cleaner on the market, different types of metering roller rubber and durometers, different inking rollers,different rollers settings, changed roller and fountain solution temperatures all to no avail, we tried another manufacturers ink and got the biggest improvement.
If you own a Komori you are not alone with this problem and although I like our Komori very much it is a very frustrating issue. Good luck

[Lennyr]

Try a 50/50 concentration of white vinegar and water, at wash up.
This works especially good with the problem you get on Komoris.
The acid in the vinegar helps to clean and desensitize chrome and copper rollers

[vniehaus]

I worked on a press with quad flow system that this exact problem would happen Isopropyl Alcohol and water would work and clean, clean, clean.

[John Arneson]

I agree with Lennyr. Clean the roller with a good chrome roller cleaner and the follow up with a vinegar water rinse with every single wash up.

[HPC]

I worked on a press with quad flow system that this exact problem would happen Isopropyl Alcohol and water would work and clean, clean, clean.

Alcohol is a good short term, we have done this too. I suspect someone has changed something to make the ink/fountain solution not agree with one another. Has your water changed?? (stuff out of the tap). We have had trouble with inks as well as fount solutions, running different even though we've been running the same brand. Flip a coin, but change either fount solution or ink, I think you have more than covered, cleanliness/sensitivity issues.

[BeauchampT]

If you are running tap water, seriously consider switching to RO, or some other process to soften up your water.

Also, have you checked that there are no deposits on your water form that could be contributing to the problem??

[Asures]

Does this problem only happen with certain stocks or is it on coated and uncoated? Any recent changes in your pressroom just happen (new plate supplier, new wash up solvents, new rollers, etc.)?

1. On Komori's, I personally have come across the chrome pan roller being pitted/blistering, and then from lack of an even water film, it transfers ink to the rubber meter and back to the chrome oscillator.

2. I have seen these new processless plates create these issues as well. The non image area is cleaned when dropping damps to the plate - all that debris has to go somewhere. Right into the dampening system!

Try etching the chromes with straight fountain solution. See if it might extend your run length before you toss in the towel.

Good luck!

[Kaoticor]

We are getting the problem on both coated and uncoated stocks. We made the switch to the Flint fountain solution about 6 months ago, but this is the first we have noted of any detrimental effects untill just these last few weeks. I checked on the water as well; we have our own water treatment plant here at the printing facility, and they report nothing has changed. I'll try the more agressive cleaning and straight fountain solution etching later on this week, I think we have some easier jobs coming up.

Thank you all for taking the time to provide your feedback!