Types of Defoamers
Oil-based defoamers use an oil carrier such as mineral oil, white oil, vegetable oil, or another oil insoluble in the foaming medium, except silicone oil. These defoamers also contain a wax or hydrophobic silica to improve their efficiency. Typically used waxes are ethylene bis stearamide (EBS), paraffin waxes, fatty alcohol waxes, and ester waxes. These products might also have surfactants to boost emulsification and spreading in the foaming medium. These are heavy-duty defoamers and usually are best at knocking down any surface foam.
Powder defoamers are similar to oil-based defoamers but have a particulate carrier such as silica. They are added to powdered products like cement, plaster, and detergents.
Water-based defoamers use types of oils and waxes dispersed in a water base. The oils are frequently mineral oil or vegetable oils, and the waxes are long-chain fatty alcohol, fatty acid soaps, or esters. These usually are best as deaerators, which means they are best at releasing entrained air.
Alkyl polyacrylates are ideal for use as defoamers in non-aqueous systems where air release is more important than the breakdown of surface foam. These defoamers are often delivered in a solvent carrier like petroleum distillates.
Silicone-based defoamers use polymers with silicon backbones with either an oil or a water-based emulsion. The silicone compound is made up of a hydrophobic silica dispersed in a silicone oil. Added emulsifiers ensure that the silicone spreads fast and well in the foaming medium. The silicone compound may also contain silicone glycols and other modified silicone fluids. These are heavy-duty defoamers and are good at both knocking down the surface foam and releasing entrained air. Silicone-based defoamers are also suitable in non-aqueous foaming systems like crude oil and oil refining. For very demanding applications, fluorosilicones may be appropriate.
EO/PO-based defoamers consist of polyethylene glycol and polypropylene glycol copolymers. The defoamers are distributed as oils, water solutions, or water-based emulsions. EO/PO copolymers typically have good dispersing properties and are often well-suited when there are deposit problems.
Applications
Anti-foams are added to some detergents to reduce foaming, which might decrease the action of the detergent. Dishwasher detergents, for example, have to be low foaming for the dishwasher to work correctly. When used as a food ingredient, antifoaming agents control foam or fizziness in preparation or serving. They are included in a variety of foods and materials for food preparation. McDonald's uses polydimethylsiloxane, a type of silicone antifoaming agent, in its oil to mitigate hazardous splashes of oil caused by foaming in fryers, so it has been listed as an ingredient in their fried menu items.
Defoamers are used in various industrial processes and products, including paper, wood pulp, paint, industrial wastewater treatment, machine tools, food processing, oil drilling, oils cutting tools, and hydraulics. Antifoaming agents are also sold as drugs to relieve bloating. One example is the drug Simethicone, which is the active ingredient in drugs such as Maalox, Mylanta, and Gas-X.
Anti-foamers are often added to paints, inks, coatings, and additives. The mixing, grinding, and chemical reactions involved in producing these materials can create foam, leading to increased production times, reduced operational efficiency, and defects in the physical product. To prevent this, antifoam is used in applications including polymer and pigment grinding, package filling, and shearing or spraying.
ABOUT CEMOTECH
→ Suzhou Cemo New Material Technology Co.,Ltd is a high-tech enterprise specialized in construction additives.
→ Estabilished in 2011 and expanded production scale in 2015.
→ Our production capacity is 10,000 tons of redispersible polymer powder, 5000 tons of polycarboxylic acid superplasticizer, 3000 tons of melamine superplasticizer, 2000 tons of defoamer, gypsum retarder, hydrophobic agent and other additives.