Fountain solution in sheetfed offset

[cementary]

What is recommended temperature for cooling fountain solution (conventional + 10% ipa) for sheetfed offset press?

 

[Cornishpastythighs]

Some suppliers recommend between 10c(50f) and 15c(59). Be careful of condensation.

 

[cementary]

That's the same recommendations i've recieved from our supplier. But in sunchemical docs i've found recommendation of 18c (65f) for water pan and 22c-26c (72f-80f) for ink train.
For today i've got very big (20c) difference between ink train temperature and fountain train temperature.
Though i wonder, what will happen if i will raise fountain temperature form 10c to 18c?

 

[Cornishpastythighs]

Why not try 15c. Are your inking rollers cooled

some reading material for you http://www.coolgraphics.dk/qa-printing-quality.html

 

[cementary]

Yep, fountain ball and two oscillators are cooled (technotrance), temperature is 20 (for fluid).

 

[Alois Senefelder]

cementary,


Have you checked the Surface Temperature of the Roller Trains ? using Infra-Red Temperature Sensor

............................. Out Flow Temperature of the Roller Trains ?


Regards, Alois

 

[cementary]

Yes, on chilled rollers it is 23 to 24. On not chilled 32-33.

 

[cementary]

Why not try 15c. Are your inking rollers cooled

First of all thanks for link.
Some new info – it turned out that tempering system was disconnected from yellow section. For now we've turned it on, (about 5 minutes ago).
So i wonder could this be the key for our problems with inconsistent printing?

 

[cementary]

Out Flow Temperature of the Roller Trains?

We don't have temp sensor on input/output flows. The best i can is to measure with pyrometer tubes with fluid – will that be indicativve in any way?

 

[Cornishpastythighs]

If you dont have one already get yourself one of these inexpensive temp guns

 

[cementary]

If you dont have one already get yourself one of these inexpensive temp guns

We've got one a long time ago. Actualy i found out that tempering wasn't working with this sensor.
Turns out – nobody cares. Most of the time when i start question things the middle-standard answer is "do not poke your nose into our affairs, it works great because it always have been this way". Now i wonder how many false statements were made due to someones insufficiency?
feel myself like "curious cementary "

 

[Alan Rand]

Glad I retired after 35 years of it. I saw a lot of industry changes and not always for the good. If you do not adapt and overcome, you will cease to have work.

 

[Green Printer]

http://www.coolgraphics.dk/qa-printing-quality.html


The following is a quote from the above web site

"Q-24: Why is water hardness important?
A: The optimal water hardness should be just below 12ºdH (German hardness degrees. 1ºdH corresponds to 10 mg CaO/liter water). Both too hard and too soft water gives printing problems. Too hard water creates f.ex stripping on the rollers making it impossible to print, while too soft water makes it difficult and sometimes impossible to get the sheets dry."

In 45 years I have never heard of ink not drying because the water is to soft. I have ran presses using steam distilled water and Never had a drying problem. Has anybody on this forum experienced drying problems using too soft of water?

 

[aqazi81]

May be that statement is because the soft water emulsifies ink more than the hard water, so more water in ink and it takes longer to dry.

 

[aqazi81]

What is recommended temperature for cooling fountain solution (conventional + 10% ipa) for sheetfed offset press?

10C in the tank so when it circulates it will get near to 12C in the tank. 25-28C for the ink temperature control. Too low temperature in ink train will cause problems in ink transfer on rollers.
Hope this helps.

 

[cementary]

10c in tank in our case means 15 on damp ductor.
Do i understand right – once temperature on rollers increase up to 29 and more – ink tends to emulsify faster and viscosity/tack drastically drops down, causing lots of printing problems?
And what about ink fountain ball? Is it enough to keep 21+ C to maintain proper ink transfer?

 

[aqazi81]

25-28 is what Heidelberg recommends for its ink temperature control unit.
Below 22 the ink transfer will reduce significantly, more ink on rollers and less on sheet.The printed work may look flat and an increase of piling may be observed.
Above 30 the ink will start to allow more water in (emulsify) and it will start to fly and mist.

 

[Alois Senefelder]

cementary,


BASICS - The Inflow/Outflow Fountain Solution fliud piping to the Press should be Insulated and a Filteration system in place.

 

[cementary]

cementary,


BASICS - The Inflow/Outflow Fountain Solution fliud piping to the Press should be Insulated and a Filteration system in place.

Alois, thanks for the info but for now we do not have problem with dampening tempering.
We have a problem with someone very f*** smart turning off sections from tempering contour and we've got some problems with some tubes in tempering contour (for duct and osc's) which we should clean during closest maintense cycle. I really hope it would help.
Everybody thanks for discussion