Structural adhesives—characteristics and application



Structural adhesives are one of the more important developments in the adhesives field because they make possible bonded assemblies in lightweight structures which take full advantage of the strengths of the materials used. Structural adhesives can be divided into two classes. One class consists of hard brittle resins typified by unmodified epoxy adhesives which have high shear and tensile strengths but low peel strength. The second class consists of a combination of resins resulting in a more ductile type of adhesive which has high peel strength along with high shear and tensile strength. One application is described here in which an epoxy adhesive is used in a design which minimizes peel forces and which causes failure of the bonded assembly in the metal. The evaluation of this design showed it to be successful.