Water in ink duct

[S.S.KULKARNI]

Hi, I've encountered a problem of water reaching to ink duct. This is happening while web offset printing on Colourmann press with tower configuration. Colour sequence is CMYK. It's being observed only in Cyan and Yellow but all units. Due to water reaching to ink duct, ink fils to transfer on ink fountain roller and the print on the papers starts disappering. It's overcome by agitationg the ink into ink duct or by removal of the water from ink duct bu air or by any other meance. It has started hapenning suddenly from the month of April. Till then every thing was fine. Can any body throw some light on the possible cause(s) of the problem?
SSK

 

[Asures]

Sounds like you're running a very "Wet" fountain solution and it's migrating up the roller train. I don't know if you have brush or continous dampening on that press but it sounds like an uneven balance of ink and water.

 

[D Ink Man]

Tell your ink company to take some of the water out of the ink. It is common practice nowadays for some ink companies to put 10-12% of water into their inks to be more competitive. To check, drawdown a mass of the ink and put on a hot plate or heat saddle. If the masstone bubbles, they're watering it down. D

 

[Dan Roll]

There are several conditions that may contribute to this. If the ink is very strong (has a very high solids content), if the air in the pressroom is very humid, if the plates are sensitive (meaning the plate background repels water to some extent), if the plate image area is inadequately oil attractive, or any combination of these conditions, (it) will cause fountain solution to accumulate in the ink fountain.

 

[S.S.KULKARNI]

This is a double width double circumference cold set press with turbo dampening system.

 

[S.S.KULKARNI]

The said ink/s were checked for volatile content by keeping the inks spreading in flat dish foe couple of hours at 120 deg.cent. The volatile content checked by this method didn't exceed 7%. This indicates there may not be water into the ink as an formulation ingredient. The values of volatile content are almost same for all colours but the problem being faced only in cyan and yellow inks.

 

[S.S.KULKARNI]

Ya. I agree. This could be possibility. The excess fount required to keep non image areas clean might be travelling all the way upto ink duct. But how to ensure that my water values are not more thaa normal. How to establish so called normal water values???

 

[Deleted member 16349]

Hi, I've encountered a problem of water reaching to ink duct. This is happening while web offset printing on Colourmann press with tower configuration. Colour sequence is CMYK. It's being observed only in Cyan and Yellow but all units. Due to water reaching to ink duct, ink fils to transfer on ink fountain roller and the print on the papers starts disappering. It's overcome by agitationg the ink into ink duct or by removal of the water from ink duct bu air or by any other meance. It has started hapenning suddenly from the month of April. Till then every thing was fine. Can any body throw some light on the possible cause(s) of the problem?
SSK

This might help you.

The Offset Pressman: Troubleshooting an Ink and Water Balance Problem


It is a similar problem.

 

[Bagfoot]

Make sure that any zero spots have the water cut back to minimum, just enough to keep the plate clean. Also make sure that the turbo is clean and calibrated to get optimum performance out of its shutters.

 

[Alois Senefelder]

Water every where !

Water every where !

Hello S.S. Kulkarni,

First, you need to ask the press crew, what input parameters have been changed?

Some questions - 1) Are the printers running to much dampening fluid?

2) Check the inflow temperature of the F.S.(press condensation)

3) R.H. of the press room - High?

My next question, do you Ink Pumping System? - what size are the Silos (1000kg) ?

Is moisture being removed from the Compressed Air System correctly?

Clean DRY air, is a crucial part of any compressed air system.



Regards, Alois

 

[GazKL440]

Do you run a roller conditioner program?

We don't..... But last week I had to put a varnish on the 4th (yellow) unit, and in the loooooong process of getting it clean enough to varnish I ran through a complete conditioning program with calcium rinses and rubber conditioners etc..... Took bloody HOURS but the unit was a bit of a mess lol!

After varnishing the 900 run job (total of 4 hrs later-- then had to reprint it the next night as the die cut was wrong!) I went back on to normal CMYK printing....

However, prior to this Herculean cleaning and conditioning effort I'd noticed a very small amount of water creeping into the ink duct and tweaking the damper settings hadn't solved it: post this bit of TLC I'm able to run a few percent less water in that unit and have seen no sign of the water returning... No mechanical changes just roller conditioning.

Perhaps running a roller conditioning program might help a little with your problem? Your pressmen will grumble a little, but it's for the best in the long run..

 

[Lukew]

Do you run a roller conditioner program?

We don't..... But last week I had to put a varnish on the 4th (yellow) unit, and in the loooooong process of getting it clean enough to varnish I ran through a complete conditioning program with calcium rinses and rubber conditioners etc..... Took bloody HOURS but the unit was a bit of a mess lol!

After varnishing the 900 run job (total of 4 hrs later-- then had to reprint it the next night as the die cut was wrong!) I went back on to normal CMYK printing....

However, prior to this Herculean cleaning and conditioning effort I'd noticed a very small amount of water creeping into the ink duct and tweaking the damper settings hadn't solved it: post this bit of TLC I'm able to run a few percent less water in that unit and have seen no sign of the water returning... No mechanical changes just roller conditioning.

Perhaps running a roller conditioning program might help a little with your problem? Your pressmen will grumble a little, but it's for the best in the long run..

A roller maintenance programme is very important if you want any life from your rollers & also rollers with a good nap.
There is nothing hard about it & once a week is a good idea: Wash up press - run roller cleaning paste for 5 mins - wash up - run decalcifier for 5 mins - wash off with water - finally end with a normal wash up.

For us the roller wash is bottcher C29 - Roller paste is Poropaste or Bottcher RE & the decalcifier is Bottcher calcium fix.

There should be no reason for excess time to go from an inked deck to a deck suitable for varnishing

 

[GazKL440]

I agree Luke..... But it's unfortunately never that simple

We run bulk run mail out 95% of the time with heavy coverage. The Hostmann bloody Steinberg ink we use tends to get EVERYWHERE. On a deck that's less than a year old, that I've pulled apart several times to clean, it still required half the rollers pulled to clean build up off the ends.

Then you get to Friday arvo: wash up day!! You've got 2 hours to go, a 10,000 run W/T to run in the 40, a full wash up to do on the 40 and the 26/5....... oh and there's 10 skids that need to be wrapped, strapped and loaded onto a truck that *should* be here soon.... And everyone else goes home...This is my usual Friday.

At this point, an extra 20 mins of roller conditioning work becomes the LAST thing you worry about.