The defoaming agent is so powerful, if you don’t believe it, take a look!
01
Foam refers to a dispersion of air, carbon dioxide and other gases dispersed in water, oil, slurry, dyeing liquid and other liquids. There are two aggregation states of foam, one is dilute foam, the interaction between bubbles is weak and will not aggregate into foam; the other is thick foam, the foam of thick foam is dense, and thick foam is the real foam. Usually, a small amount of certain substances are added to dispersions such as slurries and dye liquors to inhibit the generation of foam. This substance is called “defoaming agent”. Simply put, any such substance that can make foam disappear quickly by adding a small amount of substances is called “defoaming agent”. Most defoaming agents belong to the surfactant type. Defoaming agents must be able to reduce the surface elasticity and surface viscosity of the foam, thereby reducing the stability of the foam.
02
In food processing defoaming agents can prevent and eliminate harmful bubbles generated during food processing, making operations smooth. Oils with low volatility and strong diffusivity, or water-soluble surfactants are usually used. The most widely used defoaming agent is silicone resin, which is obtained by catalytic reaction between metallic silicon and organic chloride to produce organochlorosilane monomer, which is separated by distillation to remove by-products, and then hydrolyzed and polycondensed. Used for MSG fermentation, wine, soy sauce, sugar, dairy products, jam, etc. manufacturing, enzyme and starch extraction and processing.
03
In the papermaking process defoaming agents can prevent and eliminate harmful bubbles generated during food processing, making operations smooth. Oils with low volatility and strong diffusivity, or water-soluble surfactants are usually used. The most widely used defoaming agent is silicone resin, which is obtained by catalytic reaction between metallic silicon and organic chloride to produce organochlorosilane monomer, which is separated by distillation to remove by-products, and then hydrolyzed and polycondensed. Used for MSG fermentation, wine, soy sauce, sugar, dairy products, jam, etc. manufacturing, enzyme and starch extraction and processing.
04
Some performance characteristics of defoaming agents can be seen in the following aspects:
(1) The defoaming agent reduces the local surface tension of the foam liquid film and defoaming. Because the surface tension of the defoaming agent droplets is lower than the surface tension of the foam liquid film, when the defoaming agent is added to the foam system, the defoaming agent droplets come into contact with the foam liquid film, which can increase the surface tension of the foam liquid film. The surface tension of the liquid film around other bubbles has almost no change. In this way, the part with reduced surface tension is strongly pulled and stretched around, finally causing the foam to burst and achieve the purpose of defoaming.
(2) The defoaming agent destroys the elasticity of the liquid film, causing the liquid film to lose its self-repairing function and defoaming. The elasticity of the liquid film is usually one of the important factors affecting foam stability.
(3) The defoaming agent reduces the viscosity of the liquid film, shortens the foam life and leads to defoaming. The high surface viscosity of the foam liquid film will increase the strength of the liquid film, slow down the drainage speed of the liquid film, reduce the air permeability of the liquid film, prevent the diffusion of gas in the bubble, etc., which will extend the life of the foam and stabilize the foam.
