The foaming of an adhesive within a joint is often an undesirable situation. However, in certain circumstances adhesives are purposely designed to foam or expand. There are several performance and production benefits that can be gained from an adhesive that foams during the assembly process. As a result, foamed adhesives are being used today in a wide variety of manufacturing tasks, replacing not only conventional adhesives but also mechanical fasteners, conventional tapes, and other methods of joining as well.
There are various ways of incorporating foam within an adhesive joint. One method is to use a foamable adhesive that expands on application, and another is to use a pre-foamed backing or carrier with a pressure sensitive adhesives (i.e., foam tape). There are various polymers that can be used in these applications, and the foaming process provides the capacity to modify the polymers to meet specific application requirements.
The primary advantages that foamed adhesives offer over more conventional products are related to enhanced performance and cost reduction.