SELECTION OF STRUCTURAL ADHESIVES

When choosing an adhesive for a specific purpose and specific operating conditions of the adhesive product, the following factors must be taken into account:

- the nature of the materials to be bonded;

- terms of Use; - the level of required strength;

- features of glued construction;

- physico-mechanical and chemical properties of the adhesive;

- gluing technology.

Basic requirements for structural adhesives:

the adhesive must be neutral with respect to the materials to be bonded, i.e. not cause corrosion and not contribute to its development;

the curing of the adhesive must occur without the release of volatile substances;

the glue must not be brittle, be resistant to various aggressive liquids, depending on the purpose; the adhesive must have sufficient viability, good gap filling;

adhesive joints of metals must have high strength, independent of the effects of variable temperatures and other factors.

One of the most important indicators of structural adhesives is heat resistance. On this basis, adhesives can be divided into groups: up to 80°C, up to 150°C, up to 200...350°C, up to 700°C and above.

The technological characteristics of some adhesives and the strength properties of the joints on these adhesives used for bonding metals to each other and to non-metallic materials are given in Table. For the same combinations of materials, several adhesives with different properties are indicated, so the choice of a specific adhesive in each case will be determined by the strength of the joint, its resistance to operating conditions, the conditions of the technological processes of gluing and the requirements for ensuring the reliability of the glued structure.