Choose the corresponding ph range when choosing a defoamer
Defoamers are used to eliminate foam generated in industrial production, and their main function is to suppress foam. So how should we choose defoamers? The dynamic defoaming effect in a relatively closed small space, such as in a chamber scraper, involves gas entering the bubble. The short-term reduction of external air pressure is more conducive to the generation and stability of bubbles. Wetting agents and emulsifiers have a shrinking effect on the gas in the bubble. One is nothing, but tens of millions or even hundreds of millions are considerable.
The dynamic defoaming effect in the open space, I don’t know if you have ever come into contact with the transformation of a single-sheet flexographic printing machine into a glazing machine. The glue roller and inking roller are open in a small space and flip at high speed, and the bubble generation speed is quite fast. When the liquid that generates bubbles flows back to the storage tank or directly into the packaging barrel, it is okay if the defoaming is fast. The applicable PH range of the defoamer, I won’t say much about this. Some defoamers start very well, but the effect is much worse after being placed for a period of time. There are many influencing factors. I think there are at least two reasons 1) The defoamer is increased in volume by the surfactant 2) The main agent of the defoamer can be absorbed by the colloidal resin Temperature changes lead to changes in the surfactant’s foam stabilization and defoaming. For the same dilution, the decrease in foam stability of emulsifiers and wetting agents is inconsistent with the decrease in defoaming ability of defoamers. The system that is continuously diluted always tends to have more and more bubbles.
