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 in all units. Due to water reaching to ink duct, ink fails to transfer on ink fountain roller and the print on the papers starts disappering. It's overcome by agitating the ink into ink duct or by removal of the water from ink duct by 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

 

[D Ink Man]

What ink brand?

 

[Asures]

Ink stripping. Your rollers are hydrophilic and attracting water to the point it over powers the ink.

I'm sure there's a thread on here about it.

 

[S.S.KULKARNI]

DIC web offset inks for cold set printing on standard news print.

 

[D Ink Man]

Have DIC do a multiple point emulsification test on your 4 inks using your fountain solution. You want to see if the inks have an affinity to take on the solution over time. If they reach a point where they cannot take on more solution, this could be the source of water in your ink duct. The water has to have somewhere to go. If it cannot be properly emulsified into the ink, this is the result you get.

And with your declaration that the inks are cold set, there is less probabilty that the inks contain any significant amout of water in the formulations. This is more likely in heat set web inks. D

 

[sanshi]

check setting of ink fountain roller to ink transfer roller is heavy or normal in case heavy contact water will raised to ink duckt.