Composition and selection of defoamers
Defoamers, also known as antifoaming agents, will produce a lot of harmful foams in the process of industrial production, and defoamers need to be added. They are widely used to remove harmful foams generated in the production process of latex, textile sizing, food fermentation, biomedicine, coatings, petrochemicals, papermaking, industrial cleaning and other industries. How to choose a defoamer? First, determine the system that needs to use the defoamer, whether it is a water-based system or an oil-based system. For example, in the fermentation industry, oil-based defoamers such as polyether-modified silicone or polyether should be used. The water-based coating industry should use water-based defoamers and silicone defoamers. Select the defoamer, compare the addition amount, and refer to the price to get the most suitable and economical defoamer product. Ingredients of defoamers: (1) Active ingredients Function: breaking bubbles, defoaming, reducing surface tension: Representative substances: silicone oil, polyether, higher alcohol, mineral oil, vegetable oil, etc. (2) Emulsifier Function: Disperse the active ingredients into small particles, which are easy to disperse in water and have a better defoaming and anti-foaming effect.
Representatives: nonyl (octyl)phenol polyoxyethylene ether, soap salt, OP series, Tween series, Span series, etc.
(3) Carrier
Function: It helps to combine the carrier with the foaming system, and is easy to disperse into the foaming system. The low surface tension of the carrier itself helps to suppress foam and reduce costs.
Representatives: Solvents other than water, such as aliphatic hydrocarbons, aromatic hydrocarbons, oxygen-containing solvents, etc.
(4) Emulsifying aids
Function: Make the emulsification effect better.
Representatives: *Dispersant: hydrophobic silica, etc.; *Thickener: CMC, polyethylene ether, etc.
