How to Use defoamers correctly?
Foam has a great influence on industrial production. In production, the foam produced for various reasons needs to be treated with an antifoam agent. 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 and find the correct method of use.
1. Turbidity of defoamer
The main components of antifoaming agents are generally hydrophobic particles, silicone oil and emulsifiers. The hydrophobic particles absorb the silicone oil to maximize the effectiveness of the silicone with as little as possible. As the main defoaming medium, silicone oil has a small surface tension, is neither oleophilic nor hydrophilic, and is suspended in the system. When the defoamer is present in the middle of the foam wall, the oil and water phases are discharged to produce the defoaming effect. Consumption, when the silicone oil outside the hydrophobic particles is completely consumed, causes the foam system to be cloudy. Therefore, the amount of hydrophobic particles, silicone oil and emulsifier used in the defoaming agent and the color formation are different, which causes the performance of the defoaming agent to be very different. When the defoamer has a good defoaming effect and a long foam suppression time, turbidity generally does not occur in the system.
2, the bubble suppression time
The nature of the silicone oil in the antifoaming agent determines the antifoaming time of the antifoaming agent. The content of the silicone oil determines the consumption cycle of the antifoaming agent. If the amount of silicone oil is too small, the antifoaming performance of the antifoaming agent will not reach the required value. , Too much addition will affect the performance of the defoaming agent, and will reduce the defoaming property of the defoaming agent; the particle size of the defoaming agent determines the filtration resistance of the defoaming agent. It is filtered to produce bleaching oil, which has an impact on the foam suppression. The stirring time is also an important indicator of the antifoaming ability of the defoamer. Insufficient stirring may produce turbidity, oil bleaching, weakening of the defoaming ability, and a shorter foaming suppression time.
3, the failure problem
Acid-base stability; silicone oil can destroy the surface tension of the liquid and play a role in eliminating foam. If the anti-foaming agent has poor acid and alkali resistance, it will cause the silicone oil to decompose, resulting in reduced defoaming ability and even failure. Adding silicate to the system is generally Will inhibit its decomposition. Defoamer solubility; certain chemical ingredients make silicone oil dissolve into the system, so that the defoamer no longer has defoaming effect, but exists in the system as a surfactant, the system foam is higher than when no defoamer is added .
4. Classification of antifoaming agents
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, defoamer The types and application fields are constantly increasing, and the performance of defoamers is getting better and better.
5. How to use antifoam
When choosing a defoamer, try to choose a branded defoamer manufacturer. In this way, the defoaming agent will have fewer problems during use. According to the instructions given by the manufacturer, it can be added according to the standard ratio to achieve the best defoaming effect