Ink/Water Balance

[Randy]

Some tips

Some tips

The pressman should turn water WAY down before the first set.

Contact the ink manufacturer; I think its Hostmann, and describe your problem. They may tell you to switch your fountain solution. Some inks won't work well with all fountain solutions. Also, you use alcohol, but do you also use alcohol substitute? I like to start with alcohol substitute as a regular daily mix, then add alcohol only if the job can use it.

Do you NEED to use Resista? It is a scuff resistant ink loaded with wax, which, in my experience, grabs water and the water travels all the way to the ink fountain if you run long enough.

Although your water looks good, is it very consistent? Tap water can vary greatly.

Can your press run in a different water roller configuration (integrated, non integrated).

Does your press have metering rollers? If you run a short sheet, it helps to tighten the pan roller down on the ends to prevent water build up during the run. You can also change skew on some presses which will also help control water.

Hope this helps.

 

[Alex Arriaza]

we make measurements of our fountain solution daily and it doesn't vary to much we change the fountain every 2 days so its pretty clean, the machine im having the trouble with has an epic delta system with chrome rollers, and yes were are using resista and rapida from hostmann, ill try a new procedure to make the balance tomorrow and ill post the results

 

[Alois Senefelder]

Salient Points

Salient Points

Hello fellow Lithographers,


Free Surface Water

Even when printing with a Stable Emulsion ( water in ink ) a common occurrence is to find water present on the surface of the ink in the Duct, this is due to the formation of "Free Surface Water" at the roller train nips, then working its way back up the roller train.


Regards, Alois

A PDF - WATER -- INK INTERACTION

 

[bikozak]

You need to determine what your ink/water balance window is and use this as a guage to determine if your chemistry is right. There are different ways to do this, but here's a site with pressman tips that might help.
Once you have that, you can start trying it with different chemistry/ink/paper/blankets etc.

 

[Bloodsaler]

If your fountain temperatur is 16 Celsius degree,it`s too high.And the high temperature wil cause emulsification problem.
And from your fountain parameter,I found the conductivity is a little bit higher for a non-alcohol dampening.
Do You checked your fountain solution everyday?
About the ink&water match problem,It do happen,but rarely happens.

 

[turbotom1052]

before changing chemistry i would recomend turning the water down till your plate just begins to show an even across the cylinder scum line on the very gripper bend in the plate. If you check this scum line on all units after each pull you will be able to get an idea of how low you can go on your water. I dont think that 50 to 70% water speed is too much. Id only be concerned if i were to start out my shift with water speed in excess of 70%. This is just a number and subject to change with alot of different conditions. If you find you consistently need to run your water in excess of 70% then i might look at other possible causes. I dont know how you arrived at your present formula for fountain soultion but before changing that id make sure everything was mechanically correct, to include your metering roller setting and just how worn your metering roller is. As the metering roller wears you will usually need to increase your water motor speed to compensate!!!!

 

[INKGUY]

Thats exactly what i mean, how can i tell that, i need more info about it, like what is the type of ink that can be used with certain foutain solution, is there thumb rules to this subject_?

Alex: Not knowing all the details of your problem. You can have your ink supplier do emulsification testing. Just send them about half a gallon of the premixed fountain solution you are using and ask them to test it with the inks they are supplying to you. This will tell you if the ink and FS are compatible. Next, audit your press or presses to make sure all your temps are where they need to be. Running too cool or too hot can create problems with emulsification which can show up as ink piling and colors tracking down line. Hope this helps?