 | This article about a commercial product's advantages and disadvantages may be unbalanced toward certain viewpoints. (August 2016) |
Spray foam (expanding foam in the UK) is a chemical product created by a chemical reaction of two component parts, commonly referred to as side A and side B.[1] Side A contains very reactive chemicals known as isocyanate. Side B contains a polyol, which reacts with isocyanates to make polyurethane, and a mixture of other chemicals, including catalysts (which help the reaction to occur), flame retardant, blowing agents and surfactants. These react when mixed with each other and expand up to 30-60 times its liquid volume after it is sprayed in place. This expansion makes it useful as a specialty packing material which forms to the shape of the product being packaged and produces a high thermal insulating value with virtually no air infiltration.