Classification of Water-based Defoamers and How to Choose

Nov 18, 2020

The water-based defoamer is formulated with dimethyl silicone oil, white carbon black, emulsifier, etc., and is made into a water emulsion dispersible defoamer using emulsification technology. All raw materials and links are non-toxic, with the characteristics of fast dispersion, fast defoaming, long suppression time, stability and no delamination.
Foam and foam often accompany people’s life and production, and sometimes need to use it, such as flotation, fire extinguishing, dust removal, washing, manufacturing foam ceramics and
Water-based defoamer
Water-based defoamer
 Plastics, etc.; sometimes it is necessary to eliminate it, such as fermentation, paint, papermaking, printing and dyeing, removing the flatulence of internal organs, boiler water, wastewater treatment, and prism (or glass) manufacturing. The so-called "bubble" or "bubble" refers to the presence of insoluble gases in liquids or solids, or in independent bubbles surrounded by their films. The accumulation state where many bubbles gather together and separated from each other by a film is called foam. Bubble is a dispersed system with gas/liquid, gas/solid, and gas/liquid/solid interfaces. The latter is common in bubbles in mineral processing and oilfield systems.

Generally speaking, pure water and pure surfactants do not foam. This is because their surface and interior are uniform and it is difficult to form an elastic film. Even if they are formed, they are unstable and disappear instantly. However, there are surfactants in the solution. After the bubbles are formed, due to the intermolecular force, the hydrophilic groups and hydrophobic groups in the molecules are adsorbed by the bubble walls to form a regular arrangement. The hydrophilic groups face the water phase and the hydrophobic groups The base faces the inside of the bubble, thereby forming an elastic film on the bubble interface, which has strong stability and is not easy to break under normal conditions. The stability of the foam is related to factors such as surface viscosity and elasticity, electrical repulsion, surface film movement, temperature, and evaporation. Furthermore, bubbles are inversely related to the surface tension of the liquid. The smaller the tension, the easier it is to foam. In life and production, the appearance of bubbles sometimes brings a lot of inconvenience to people, so it must be defoamed.

Any factor that can destroy the stability of the foam can be used for defoaming. Defoaming covers two factors: "foam suppression" and "foam breaking". Organosilicon defoaming agent has this function, it can reduce the surface tension of water, solution, suspension, etc., prevent the formation of foam, or reduce the original foam, usually has a selective effect. General physical defoaming method is difficult to defoam instantly, while chemical defoaming and interface chemical defoaming are very fast, convenient and efficient.

In a nutshell, defoamers refer to agents that have chemical and interface chemical defoaming effects. As defoamers, there are lower alcohols, mineral oils, organic polar compounds and silicone resins. Its forms are oil type, solution type, emulsion type and foam type. As a defoaming agent, it has strong defoaming power, chemical stability, physiological inertness, heat resistance, oxygen resistance, corrosion resistance, dissolved gas, breathable, easy diffusion, easy penetration, insoluble in the defoaming system, and has no physical and chemical effects. Low foaming agent dosage and high efficiency.

The classification of water-based defoamers can be divided into three categories: polyethers, silicones, and mineral oils.
According to its purpose, application field, dosage, etc., select it in a targeted manner.
Industrial defoamers can be divided into.
(1) Silicone defoamer
There are also many types of silicone defoamers, with strong defoaming ability, heat resistance, oxidation resistance, low price, and more applications in the paper industry.
(2) Polyether defoamer
This type of defoamer is resistant to high temperatures and has strong dispersibility in water. Wide range of applications.
(3) Mineral oil defoamer
This kind of defoaming agent is added a lot but has excellent defoaming and anti-foaming ability and good compatibility with the foaming system! Compared with silicon defoamers, no silicon spots are his advantage! But relatively speaking, mineral oil defoamers are not widely used.
Whether a good defoaming agent plays a good role depends on whether it is added properly and correctly in addition to the defoaming agent itself. It is generally more effective to use two or more defoamers than a single defoamer with a higher single ratio.