Section Six Adhesive Technologies
As mentioned previously, joining materials with adhesives offers significant benefits over traditional methods. Despite the benefits of adhesive joining, choosing the right adhesive for a particular application can still be challenging due to the vast variety of adhesives available in the market. This section provides a summary of the different chemistries, adhesive families, physical and chemical properties, advantages, considerations and common applications, as well as the most important elements for ideal adhesive selection as they relate to the respective chemistry. If in doubt about any application, an adhesive expert should be consulted.
6.1 Definition of an Adhesive
It is important to first clarify and understand the following key terminology and concepts. Doing so will help in understanding different adhesive types and their properties.
Adhesive: An adhesive is any substance that, when applied to the surfaces of the materials (substrate), bonds the surfaces together and resists separation. Adjectives may be used in conjunction with the word ‘adhesive’ to describe properties based on the substance’s physical or chemical form, i.e. ‘flexible’ adhesive or ‘hybrid’ adhesive.
According to DIN EN 923, an adhesive is defined as a non-metallic binder that acts via adhesion and cohesion. ASTM D907-06 defines an adhesive as ‘a substance capable of holding materials together by surface attachment’.