fountain system mystery

[Hannes]

Hello,

I'm writing from Estonia, and we have quite hard water here. Hardness is about 12dH - 18dH degrees.
Yesterday I was measuring tap water and it was neutral pH 7. Then I measured solution from printingmachine's tank and pH was over 8! How is it possible?? OK, the machine was not working in the moment and the pump was shut off put still. I understand if there is no buffer in it, then the pH should be 7, the same as tap water. How can it rise like that?

Another question is about Hostmann's Combifix XL. On the label there is written that this additive is for water with hydrocarbonates up to 250 mg/L. Does it mean that it is meant for ''soft'' water?

 

[HachiZenki]

We have quite hard water here as well. It's naturally filtered thru rock to settle in underground aquifers so you'll see many a fountain around here with white calcium/mineral buildup. We solved our water problems by using a reverse osmosis system.

 

[The Ditmeister]

We also have had to deal with some extremly hard water in Norfolk UK. The best solution is indeed an RO unit for constant stable water.

 

[egutwillig]

Possible Fountain Mystery Answer

Possible Fountain Mystery Answer

Increase in pH may easily be caused by calcium carbonate from paper. Fount buffering action ususally overcomes excessive pH change but there will be a increase in conductivity.

I agree that to stabilize the situation you should persue a water treatment unit to assure that your starting water is always consistent. There are several approaches employed worldwide: 1. RO water with added "rehardiner" and 2. Using a treatment unit that produces "process water" (water at a consitent pH and conductivity after having been filtered, R/O treated, etc. by the system).

Option 2 (e.g. AquaFlo) is widely used in North America (also available in Europe) while option 1 is widely used in Europe. The process water approach is probably more consistent and secure as it is not reliant on addition of an additional chemical, which may or may not be added correctly. Also, water coming from the unit is not almost zero pH as with R/O water. However, the hardness is allways the same and no rehardiner is necesssary to work with various founts.

For additional support or to inquire on the options presented above, I encourage you to contact Mr. Jean Decone of Prisco Europe at: [email protected]

 

[GJOHN]

pH is on a logarithmic scale. So 1 unit higher than 7 means it is 10 times more alkaline and 2 units means that it is 100 times more alkaline. On the other hand 1 unit less than 7 means that it is 10 times more acidic and 2 units lower means that it is 100 times more acidic. It is high time for pressrooms to start measuring pH and monitoring it.
George John
269-216-8088

 

[CD102]

Yes, it should be measured and it should be measured accurately. It's like anything else. If the tool you are using to measure something isn't properly calibrated and accurate, the numbers that you get for that tool are meaningless. My last employer expected us to chart the pH and conductivity of our fountain solution based on measuring devices in the chilling tank. On one press the pH read over 14 so you knew that that the tool was broken, but it never got fixed.

 

[GJOHN]

CD102, I agree completely. The pH/conductivity meter I used to take to pressrooms was worth about $500.00. It also had a thermometer in it. I used to calibrate it every day. Many times I have found out that the temperature of the fountain tank was too hot. But the poor ink/fountain solution guy got all the blame for poor performance and everybody pointed fingers at each other. Unfortunately many ink/fount companies are getting rid of good service technicians to save money. It will hurt our industry.
George John
269-216-8088

 

[RNRPRINTINGNMAILING]

why not just buy stilled water i use it in my presses all the time and i have no problems

 

[mrheidelberg]

Distilled water in multi unit presses would work out very expensive ........ an RO unit that controls the water for all the presses would be a much cheaper option.