Ink building up on komori L-640 metering rollers

[peter61]

We've been having alot of trouble lately with process ink(flint)building up on our metering rollers(bottcher+rodadyne)we use pressmax HDA-64(6oz per 5 gal of ro water) and emerald jr.(15 oz per 5 gal of ro water)any ideas?Thanks.

 

[Dan Roll]

If you drain out the fountain solution and replace it with fresh material does the situation improve?
Try testing fresh fountain solution for foam stability (shake some up in a bottle and watch what happens) and then testing some fountain solution from the circulator. If the solution from the circulator foams, that will be a clue.
At what temperature are you running the fountain solution?

 

[spider]

The build up on Metering roller

The build up on Metering roller

I have found 4 common reason
[1] Temperature is too high in the water tray
[2] The unit is running too hot
[3] solutions to low
[4] Metering roller is set to hard

 

[Lennyr]

Maybe it's not your fountain solution

Maybe it's not your fountain solution

Not sure where you are, but here in California we've been struggling with the new press chemicals that we are now mandated to use for wash ups. One thing that I've noticed on my press is that some of these chemicals cause the exact problem that you have (they don't last long).
A couple of the brands I've used require that I clean my chrome rollers every day. At any rate cleaning the chrome rollers is always my first step when having this type of problem.
Maybe that's too obvious?
Lenny R.

 

[peter61]

I work in P.A..we run 24/7 I drain the tanks,flush with Prisco royal flush,turn off the chillers and run hot water through the lines,the press has cooled vibrator rollers(3 of them per unit)I keep my fountain tank temp. at 55 degrees,at the pan it reads 62 degrees which I think is fine.When I complete the tank cleaning the meters stay clean for 3 or 4 hours maybe but the black and yellow seem to always take ink,magenta rarely and cyan some times.The tanks do have alot of foam in them.When we gum the steels(chrome vibrators) it helps for a little while,but not long.The press is a Komori l-640 with a coater(1996)

 

[GJOHN]

There are some founatin solutions that are very aggressive and can break the ink down very quickly. When the ink/water emulsion is not correct, Ink in water VS tiny droplets of water in the ink film, the emulsion is not stable and can over-power ink at the printing nip. When the ink/water emulsion doesn't move forward, it feeds back. Also if the paper has a high hold out, it will not receive the ink or water very well. Working with your ink technical rep. and fount rep. is the way to go. Change only one thing at a time. A tighter body ink or a milder fount seems to be the answer if all other parameters are set correctly on the press.

 

[Cornishpastythighs]

Could the problem be unit related, you say black and yellow are the worst, have you tried other inks in those units? Maybe the steels are worn out and need replacement (14 years old)
just a thought

 

[jbeniston]

I think your tank temp is a little too high. Try 10.5 C (aprox 50F) in the tank. Are your metering rollers cleaned regularly, with a good metering roller cleaner. After they have been cleaned and dried it is possible to gum them up with the etch you use, it will not damage the rubber but might help to desensitize them. Try increasing the etch a little and see what happens. The foam in your tank is not good. Usually it means air is getting in somehow. What kind of tank is it. Is there a venturi on it that can be adjusted? Can the return flow be regulated? Slowing it down might help, also in this case watch the in flow as it might be too fast and cause overflows. Getting rid of the foam is a good thing. You cannot dampen the plate with bubbles.

 

[peter61]

The tanks are Royse,the water flow is at a minimum,we clean the meters often,I've not tried to gum the meters yet,only the chromes,I've had the black and yellow in differant units and it's still the same(building up on the metering rollers)

 

[jbeniston]

It sounds like an ink problem since it's following the units you put the black and Yellow on.
I don't think it's the Royse units as you most likely have one tank per unit and the black and yellow pile on the M rollers no matter which unit you put them on.
Do your alcohol misers still have that gold coloured electrode in the top of the plastic cap?
Make sure you keep them clean, I'm sure you do this, but use the eraser on the end of a pencil to polish them, just spike the eraser onto the needle and give a few twists, all the oxidation will be gone and they will work like new ones.
I would call in the ink supplier and get them involved.

 

[Alois Senefelder]

re Metering Roller Ink Build- up

re Metering Roller Ink Build- up

Hello peter61 also all other "Sheet-fed Printers"


I suggest you read the 4 page PDFs I have posted on the Thread: Web Offset Newsletter

posted on 24/10/2009 for the Americans ! 10/24/2009


Regards, Alois