Choosing the Right Foaming Agent for Your Project

The foaming agent is an additive which increases the fluidity of a liquid or the gas it contains and reduces its surface tension, thereby allowing the liquid to form bubbles. There are many different types of synthetic foaming agents, each with different properties and characteristics. Choosing the right one for your project is vitally important, as it will determine your success or failure.

The most commonly used foaming agents are sulfates, such as Sodium lauryl sulfate (SLS), or alkyl sulfates like Sodium Lauryl Ether Sulfate (SLEE) and Cocodiethanolamide (CED). Those that contain ionic surfactants generally have higher foam multiples than those that do not. However, some anionic synthetic surfactants can cause foaming problems because of their low surface tension and poor interfacial characteristics.

Water-based synthetic firefighting foams are often referred to as aqueous film-forming foams (AFFF) and include surfactants such as aqueous ammonium sulfate, and hydrocarbon-based surfactants. Aqueous AFFFs are designed to flow rapidly over hydrocarbon fuels and create a water film to cool the fuel, which stops the formation of flammable vapors and extinguishes the fire by smothering. Water-based AFFFs can also be destroyed by polar solvents and require alcohol-resistant aqueous film-forming foams, or AR-AFFF.

Protein-based foaming agents, such as Mearlcrete, have excellent strengths but are less well suited for projects with long pumping distances or very high lift heights. The new generation of AERLITE products, such as Aerlite HCR and Aerlite iX, can meet those challenges by producing a flexible cellular concrete. This is achieved by blending the performance of the protein-based products with the agility of the straight synthetic products.