metering roller

[brunolobo]

Hello dear friends!I am new at this forum but i hope that someone can help me,i work with a komori lithrone 428 from 1996 and i have a problem with my metering roller that is always full of ink i clean it and after 2000 or 3000 prints the ink is there again i use fuji ctp plates ,toyo ink and alccool with varn supreme(8 per cent alcool and 4 per cent of supreme).Ihope to have someone that can help me.
Thank you.

 

[akiyama_king]

does ur water fountain ever run dry while printing?

 

[brunolobo]

Yes the fountain is always cold 8 degrees celsius.I have make also a cleaning of the dampening unit including the circuit and nothing seems so solve it .If you have any sugestion i will apreciate.

 

[brunolobo]

Yes .And the fountain is always cold 8 degrees celsius.I have make also a cleaning of the dampening unit including the circuit and nothing seems so solve it .If you have any sugestion i will apreciate.Do you think that the chrome rollers have any problem.

 

[arfamoe]

You could try a chrome roller desensitizing procedure every night at shutdown and at weekends. If your chromes are original from 1996 they may need some help. There are various methods used,
1.clean chrome with alcohol to remove any ink residue.
2. Clean/scrub chrome with good quality plate cleaner not the abrasive stuff.
3. wash this off with some fountain solution.
4. Coat chrome with a thin layer of 14 Baum gum arabic (not the synthetic stuff)
Leave overnight or weekend and this may breath some new life into your chromes.

 

[GazKL440]

Trial some different fount solutions too, we had some issues with metering rollers inking up badly and a different fount more suited to the ink we regularily use cleaned them up. De-sensitizing will help but correct chemicals will help more in the long run.

 

[dana]

I've had very good results with Prisco's Chrome roller cleaner for the chrome rollers. At the end of the shift just apply on the chrome rollers and leave on over night/weekend. As far as start up in the morning, engage the dampener as usual and it should clean off before dropping the forms to the plate.

good luck
-Dana

 

[brunolobo]

Thank you all for your precious help i will try everything.Cheers.

 

[Alois Senefelder]

re Metering Roller

re Metering Roller

Hello brunolobo, you are running too cold -- fountain solution !! 10 - 12 degrees Celsius is the recommended Temperature, you are creating a "Thermal Shock" to the Inking System !


Regards, Alois

 

[arfamoe]

There's also a product called MRC (metering roller cleaner) available in North America, not sure about anywhere else. This stuff works great but is not the most human friendly solvent i have worked with, Your health and safety people may have a fit if you get it, but for cleaning Metering Rollers and bringing them back to life i have not found a finer product (just wear a mask when you use it)

 

[tmason]

Funny how we can use MRC with Acetone but not alcohol in our fountain solution. It will kill you but it's "better" for the environment.

 

[Paultheprinter]

herro,

You say that there is ink building up on the chrome roller but does it also build up on the pan roller? My only concern is with the amount of supreme fount you run. If im correct you stated you run 4% fount with 8% ipa, if this is the case then you could be emulsifying the ink and combined with the quality of your old metering rollers could be the cause, my opinion of supreme was that its sh*t, its fails to lubricate up to 2.5-3% then causes emulsification after that point but every enviroment is different and this product must have been heavily tested prior to release and also developed during its life.

Hope this helps

Paul

 

[pthielen]

Metering roller

Metering roller

Go over the roller with etch, it should desensitize it.

 

[metalfab]

yup ink emulsification!!! i suggest do a trial and error....try different pH,conductivity,alcohol %(how good your IPA?),water hardness make a chart see what value suit for your press. every press have a different fountain setting due to the environment factor,types of ink, source of water and many more.just try to help any another opinion welcome !!!!

 

[Ironside]

I believe I might be having what you described as a thermal shock to the ink, we get an unusually light band across our plates only later in the day, after the ink train has warmed up, in addition, it only appears on a new set of plates after the press has been idling between change overs. It does disappear after about 1,000 - 1,500 impressions. Our water temperature at the chiller is 50 degrees Fahrenheit and 63 degrees at the fountain. We see the problem once the ink train gets hot, the hotter it is the more of a problem. The light bands are exactly the same distance as the diameter of the water forms. So in summary.

Light bands approximately 1/16-1/8 inch thick beginning at the head of the sheet and repeating every 6.28" which is exactly the radius of our water forms.

Bands appear on the first 50 sheets in the morning but quickly disappear.

Bands appear on at least 750-1,000 sheets as the ink train heats (later in the day) up than disappear.

Bands appear in every unit but more dominant in Cyan and Magenta.

Can replace ink and water on press late in the day and still get bands.

have replace water forms and metering with new 20 durometer (we checked) rollers.

In the morning problem is gone! Its kinda funny to watch the press technicians tell us the fixed it, than we say, hang out for a bit......3hrs later its back.

The problem is related to the temperature of the ink train, the hotter it gets (later in the day) the worse it is, ink train cools off over night problem solved. Press is run long enough with a hot ink train to heat up the metering and water forms problem goes away. It appears to be the temperature difference between the water system and the ink system.

Press - Ryobi 524 GX 2007 4 color

Ink - K+E F1 Drive (we have tried many others same problem)

Fountain solution - tried many, no change currently reduced to 2 ounces fountain and .4 ounce alchohol sub per gallon, we have run way up on both and way down no change.

We have had Fuji in to help with this and no answer.

I am intrigued by the concept of thermal shock and would like to learn more about this idea.

In the morning we are going to raise our chiller temperature to 65 degrees, which should raise the temperature at the fount to 70-72 degrees, about 15 degrees warmer than we are now, if that works than thermal shock whatever that is was the culprit.

I will let you know.

 

[Alois Senefelder]

re Metering Rollers

re Metering Rollers

Hello Ironside,

I have posted lots of PDFs on this forum so there should be some that will be of interest and answer your problem.

Regards, Alois

 

[D Ink Man]

You need a different ink and fount. Your ink and water are not forming the needed micro emulsion.Try an ink that will have better affinity for the fountain solution. Ask your ink supplier to do Surland curves and report the percentage back to me. I promise you the curve will be flat after 5 minutes and the inks belly will be full. Let me know. if they don't want to do the Surlands,contact me and I'll give you probable combinations of ink and fount that will run on the various gamut of paper stocks and coverages. No problem~!