How to use defoamers correctly
Foam has a great impact on industrial production. In production, foam produced for various reasons needs to be treated with a defoamer. There may be some problems in the process of using the defoamer. Let us analyze the problems in the use of the defoamer one by one to find the correct method of use.
1. Turbidity of antifoaming agent
The main components of the defoaming agent are generally hydrophobic particles, silicone oil and emulsifier. The hydrophobic particles adsorb the silicone oil, so that the maximum effect of the silicone can be achieved with as few as possible. Silicone oil, as the main defoaming medium, has a small surface tension and is neither oleophilic nor hydrophilic. It is suspended in the system. When the defoamer is in the middle of the foam wall, the oil and water phase is discharged to produce a defoaming effect. Consumption, when the silicone oil outside the hydrophobic particles is completely consumed, the foam system becomes cloudy. Therefore, the amount of hydrophobic particles, silicone oil, emulsifier, and color used in the defoamer are different, which results in very different performances of the defoamer. When the defoaming agent has a good defoaming effect and a long foam suppression time, generally no turbidity occurs in the system.
Second, the foam suppression time
The properties of the silicone oil in the defoamer determine the defoaming time of the defoamer. The content of the silicone oil determines the consumption cycle of the defoamer in use. If the amount of silicone oil is too small, the defoaming performance of the defoamer will not reach the required value. Too much addition will affect the performance of the defoamer and reduce the defoaming performance of the defoamer. The particle size of the defoamer determines the filter resistance of the defoamer. Too large a particle size may cause the defoamer to be easy. It is filtered to produce bleaching oil, which has an effect on foam suppression. Stirring time is also an important indicator of the foam suppressing ability of defoaming agents. Insufficient stirring may produce turbidity, oil bleaching, weakened defoaming capacity, and shortening the foam suppressing time.
Third, the problem of failure
Acid and alkali stability; silicone oil can destroy the surface tension of the liquid and play a role in eliminating foam. If the defoamer has poor acid and alkali resistance, it will cause the silicone oil to decompose, resulting in a decrease in defoaming capacity and even failure. Adding silicate to the system is generally Will inhibit its decomposition. Defoamer solubility; certain chemical components dissolve silicone oil into the system, so that the defoamer no longer has a defoaming effect, but exists as a surfactant in the system. The foam of the system is higher than when no defoamer is added. .
From the first generation of mineral oil defoamer to the second generation of polyether defoamer, the third generation of silicone defoamer, polyether modified polysiloxane defoamer, The types and application fields are constantly increasing, and the performance of defoamers is getting better and better.
How to use a defoamer
When choosing a defoamer, try to choose a branded defoamer manufacturer, so that the defoamer will have fewer problems in the process of use. According to the instructions given by the manufacturer, add the standard proportion to achieve the best defoamer. Bubble effect.