Commonly used defoaming agents can be divided into silicon (resin), surfactants, alkane and mineral oil according to different components.
1, silicon (resin) class
Silicone defoaming agent is also known as emulsion type defoaming agent. The use method is to emulsify silicone with emulsifying agent (surfactant) and disperse it in water and then add it to wastewater. Silica powder is another kind of silicon defoamer with better defoaming effect.
2, surfactant class
This kind of defoaming agent is emulsifier actually, use the dispersive action of surface active agent namely, make the material that forms foam maintains stable emulsification state dispersing in water, avoid to generate foam thereby.
3. Paraffins
Paraffin paraffin defoaming agent is made of paraffin paraffin wax or its derivative emulsified and dispersed by emulsifying agent. Its use is similar to emulsified defoaming agent of surfactant.
4. Mineral oil
Mineral oil is the main defoamer. In order to improve the effect, sometimes mixed with metal soap, silicone oil, silicon dioxide and other substances used together. In addition, in order to make mineral oil easy to diffuse to the surface of foaming liquid, or make metal soap evenly dispersed in mineral oil, sometimes can also add a variety of surfactants.
Advantages and disadvantages of different kinds of defoaming agents
Mineral oil, amide, low alcohol, fatty acid and fatty acid ester, phosphate ester and other organic defoaming agent research and application earlier, belongs to the first generation of defoaming agent, it has the advantages of easy access to raw materials, high environmental performance, low production cost; The disadvantage lies in low defoaming efficiency, strong specificity and harsh use conditions.
Polyether antifoaming agent is the second generation of antifoaming agent, mainly including straight chain polyether, alcohol or ammonia as the starting agent of polyether, polyether derivatives esterified by terminal group three. Polyether defoaming agent is the biggest advantage of strong foam inhibition ability, in addition, there are some polyether defoaming agent with high temperature resistance, resistance to strong acid and alkali and other excellent performance; The disadvantages are limited by temperature, narrow field of use, poor defoaming ability and low bubble breaking rate.
Silicone defoaming agent (the third generation of defoaming agent) has strong defoaming performance, rapid defoaming ability, low volatility, non-toxic to the environment, no physiological inertia, wide range of use and other advantages, so it has broad application prospects and huge market potential, but the anti-foaming performance is poor.
Polyether modified polysiloxane defoaming agent has the advantages of polyether defoaming agent and silicone defoaming agent at the same time, which is the development direction of defoaming agent. Sometimes it can also be reused according to its inverse solubility, but at present there are few kinds of such defoaming agents, which are still in the research and development stage, and the production cost is high.
Post time: Mar-08-2022
