Foaming agents promote the formation of a large number of materials of suitable size and stability foam in the medium. Foaming agent action principle: The foaming agent should be an organic material with different polarities, the polar group is hydrophilic, and the non-polar group is friendly, so that the foaming agent molecules are oriented at the interface between air and water, most of which The foaming agent is a surface active substance and can strongly reduce the surface tension of water. The blowing agent is added to the water, the hydrophilic group is inserted into the aqueous phase and the lipophilic group is inserted into the oil phase or erected in the air to form an alignment on the interface layer or surface, thereby reducing the interfacial tension or surface tension. In general, an aqueous solution containing a very small amount of a foaming agent has foaming properties！