Conductivity of Fountain solution

[pacificiam]

hi

I just want to know what is ideal conductivity for sheetfed offset press?

How to derive it?


I rellaly eger to know

 

[Cornishpastythighs]

There is no 'ideal' conductivity. Every plant uses different fountain solutions and different water sources(RO, DI, Distilled, Town water, mountain) you get the message. Your ideal conductivity will be what works best for your ink, Plates,Water and fountain solution. No point anyone telling you that 800 is the best number when you have water that starts at 500 hardness.
Look up how to make a pH/Conductivity graph and make one for your particular fountain solution using your water source.
Good luck

 

[pacificiam]

Thank you!!!

Any other suggestions

 

[CJT]

Constant Conductivity

Constant Conductivity

Once you have established the best conductivity for your set up the trick is to keep it there, With typical proportioners you set a fixed ratio and hope that it keeps your conductivity constant throughout
the run, problem is that doesn't always happen.

We are introducing a Fountain Solution Control system that gives you constant conductivity. You program in the conductivity that is best for your set up and our unit will actively measure the conductivity of the working solution live and vary the replenishment ratio based on the actual conductivity. EC Doseing.

In addition all the data gathered by our system is recorded and daily processing reports are sent out to you showing the key operating parameters, Conductivity, pH and temperature. This data is presented in graph form and as a written report.

There is more this unit can do but space here is limited.
If you would like more information contact me off line and I would be happy to provide it.

 

[pacificiam]

HI CJT

Good to know about your product.
Can you please send me all this thing in detail on mu email ID [email protected].

Thank you!!!

 

[Mogilski@HUS]

First you need to see where you are with your water and your current fountain solution mix ratio.

Take a sample of your water source and measure the conductivity by itself.

Then mix a measured gallon of your working fountain solution by hand. Use a measured gallon of water then add the fountain solution to it at your current mix ratio. If you are using a 2 step solution you can measure each step separately and see which product moves the conductivity the most. After you have mixed the gallon of working fountain solution. Take your final conductivity reading.

This will be your baseline conductivity. You can also check this number against the water your dosing system is producing and see how close it is, they need to be calibrated/repaired from time to time.

So now you can take reading after every job, half day, day or week and see how much your conductivity rises. On average most shops are dumping the water once a week. If there is a cost issue and you are needed to run it as long as possible then note the conductivity when you start and again when you start to have print issues. Then substract 200 from the conductivity where it failed and at this conductivity number is when you would change out the water. To prevent unpredicted downtime.

Example:

Water sources: 0070
Fountain solution: 1100
Total conductivity: 1170 (compare this value to your dosers)

Print issues start at: 2400
Subtract -200
Change water at: 2200

So now you know your start point, whether your dosers are accurate and when you need to change your water.

Hope this helps