|Search By Accuracy|
Accurate printing ink / fountain solution concentration control is essential for high-quality results in printing. Low concentration can cause drying on the non-image area of the plate resulting in tinting, scumming and blanket piling. High concentrations can bring about over-emulsification of the printing ink. This results in weakening of color strength and changes in ink. Correct concentration will allow the non-image areas of the plate to be appropriately printed.
pH was the test relied on to determine printing ink / fountain solution concentration, but conductivity testing is recognized as a much more accurate method. Many modern printing solutions are pH stabilized, so only small changes in pH are seen even when dramatic changes occur in solution strength. Conductivity measurement is a fast and easy test which is more indicative of printing ink / fountain solution concentration than pH. pH is still important, however, with unbuffered acid fountain solutions. Checking both conductivity and pH can provide valuable information.
"I'm the Printing Manager at a corrugated box factory in Fremont, Ohio. I use the Hanna portable HI 9125N pH meter daily to check pH of our flexographic printing ink. The Hanna meter is made for industrial use and is capable of withstanding the dust and rough environment in our corrugated box factory. The battery life is exceptional, the display is impressive and easy to use. By simply dipping the probe into the ink, you'll get an instant reading of your ink's pH. I have 4 meters and it's real simple to calibrate them so they are always accurate. I use the #7 and #10 buffer for a good ink range. We keep our ink at 9.0 for good run-ability and trapping of colors. With using the Hanna meter's, we do not have any problems with our ink."
- R.Darr, OH