The silicone oil or silicone paste is made into a silicone oil emulsion under the action of strong stirring or emulsifier, which can effectively improve the dispersibility of the silicone oil in the water phase. So it is widely used as a defoamer in water systems. Emulsion defoamers are also the most widely used and most widely used defoamers for silicone defoamers.
Emulsion type silicone defoamers are generally formulated with dimethyl silicone oil, emulsifier, emulsion stabilizer and deionized water. The emulsifiers used are mainly non-ionic emulsifiers with low foaming properties, such as Span, Tween, and polyethylene glycol. The effect of mixed emulsifiers is better than that of single emulsifiers. The particle size of silicone oil emulsion is the most important control index for emulsion type silicone defoamers. To obtain silicone oil emulsion with high defoaming efficiency and good storage stability, the particle size is usually required to be less than 10μm.
Therefore, in addition to selecting suitable emulsifiers and mixing and grinding process conditions, thickeners such as polyvinyl alcohol and methyl cellulose can also be added to increase the viscosity of the continuous phase.
When using emulsion-type silicone defoamers, you should first understand the temperature, acidity and alkalinity of the foaming system, because they will affect the stability of the emulsion and even cause demulsification.
Although emulsion-type silicone defoamers have the disadvantages of difficult long-term storage, easy delamination, and easy deterioration, they have the characteristics of convenient use, wide application area, obvious defoaming effect and moderate price. All are still welcomed by users, and with With the advancement of process technology, emulsion-type silicone defoamers will have greater room for development.
Dissolve simethicone in a suitable solvent to make a silicone solution type defoamer. Use organic silicon defoamers made from organic solvents such as polychlorinated ethane, toluene and xylene. It can be used for the defoaming operation of oil-soluble media; and it is a silicone defoaming agent prepared with water-soluble organic solvents such as hexanediol and glycerin. It can be used for defoaming water solution. The preparation process of solution-type silicone defoamer is very simple. Easy to use, silicone oil is dispersed in the foaming liquid with the help of organic solvents to play a defoaming effect. At the same time, some solvents will also play a defoaming effect during the diffusion process. However, this method has not been widely used, mainly because a large amount of use will increase the cost of defoamers and may cause environmental pollution.Top Win is one of the leading & professional manufacturers with more than 20 years' experience, have domestic top-level engineers in silicone surfactant industry. We specialized in producing all kinds of SILICONE BASED new materials and specialized in research, production, sales and marketing in silicone-based performance materials. Provide good OEM&ODM service.Our products are mainly used in polyurethane foam, Agriculture, Coatings and Inks, Leather & Textiles, Pulp and Paper, Cosmetic industry, etc.