In industrial applications, the bonding strength of adhesives directly affects the stability and reliability of products. If the adhesive strength is insufficient after curing, it may be related to the following factors:

1. Inadequate surface treatment

The cleanliness of the bonding surface directly determines the adhesion effect of the glue. If there is oil, dust, moisture or other contaminants on the surface of the adherend, the adhesive will not be able to fully bond with it, resulting in bonding failure. It is recommended to use a suitable organic solvent (such as isopropyl alcohol or acetone) for degreasing and ensure that the surface is dry and clean.

2. Improper control of the curing process

The curing of adhesives is usually divided into three stages: initial curing, basic curing and post-curing. If the temperature is not up to standard, the curing time is insufficient, or the recommended process is not followed during this process, the adhesive layer will not be completely cross-linked, which will seriously weaken the final bonding strength.

3. The bonding gap is too large

Especially when using anaerobic adhesives, a large bonding gap can easily lead to air entrapment, affecting the curing reaction. The ideal bonding gap should be controlled within the recommended range of the product as much as possible (such as 0.05-0.10mm). If necessary, the gap can be adjusted with the help of metal gaskets or mechanical compression.

4. The thickness of the adhesive layer is unreasonable

If the adhesive layer is too thick, it will lead to incomplete internal curing, and if it is too thin, it may not be able to bear stress. The recommended adhesive layer thickness for most structural adhesives is 0.05-0.10mm, which should be adjusted according to the product instructions and actual application.

5. Environmental factors

The temperature, humidity and air circulation of the construction environment will affect the curing process of the adhesive. For example, low temperature will prolong the curing time, and high humidity environment may cause the glue to absorb moisture, thus affecting the strength. Construction should be carried out under the environmental conditions recommended by the manufacturer as much as possible.

6. Influence of the material itself

Different materials have different surface energies, and their bonding abilities with adhesives also vary. For example, carbon steel surfaces are easy to bond, while metals such as aluminum and zinc may require special primers or plasma treatment. Choosing a matching adhesive and a suitable substrate is the prerequisite for achieving a good bonding effect.