Industrial pH meter for measuring and monitoring fountain solution
1. Main components of moisturizing solution
The main components of the fountain solution are buffering agents, preservatives, plate protectors, desiccants, algae inhibitors, etc. Among them, buffering agents have the greatest impact on the pH value of the fountain solution.
2. The function of buffer
a) The function of a buffer is to stabilize the acidity of the fountain solution, as tap water is usually neutral. In order to achieve the required pH value (5-6) for normal printing, acid needs to be added to the fountain solution to maintain a weak acidity. The carbonates in the water will react with the added acid, causing an increase in pH value. At this time, a buffer needs to be added to maintain a stable pH value of the fountain solution.
b) At the same time, buffering agents also have a significant effect on alleviating the influence of cleaning agents and other factors on the fountain solution. But as the amount of buffer added changes, the pH value of the fountain solution will fluctuate significantly. Improper addition can also affect the service life of printing machinery and hinder ink drying, especially for inks containing metal pigments.
3. The influence of water on pH value
Water also has a significant impact on the pH value of the fountain solution. The water quality of tap water can be soft or hard. Water with high metal cation content is hard water, while water with high anion content is soft water. The high hardness of water will increase the pH value of the fountain solution. When preparing the moisturizing solution, the water's softness and hardness should be adjusted according to actual needs, with a suitable range of 10 ° dH. It should also be noted that changes in water temperature can affect the concentration of ions in the water. So controlling the hardness and temperature of the water is necessary to achieve the best effect of the fountain solution.
The necessity of using industrial conductivity meters
Control conductivity to ensure stable pH value
To ensure a relatively stable pH value of the fountain solution, an advanced method is to monitor the conductivity of the fountain solution while controlling the amount of buffer added and the hardness of the water.
Conductivity meter measurement and monitoring of lubrication solution
As the concentration of the fountain solution increases, the hardness of the water and the temperature of the water change, the conductivity of the fountain solution will increase, and the pH value will decrease; On the contrary, if alcohol is added to the fountain solution, the conductivity of the fountain solution decreases and the pH value increases. After testing with an industrial conductivity meter, the conductivity of the fountain solution should generally be controlled within (1400 ± 200) μ S/cm, but due to the influence of dust, ink, and other impurities, the conductivity is around 800 μ S/cm~2000 μ Within s/cm, it is also allowed, but when the lubricant appears to be significantly contaminated, it must be reconfigured.
