30 ноября, 2015 
Pokraskin One of the benefits of adhesives is that they will fill gaps between poorly fitting parts or parts with large manufacturing tolerances. The cure of epoxies is not affected by the gap between the parts but cyanoacrylates are very much driven by this gap and are limited to gaps of less than 0.2 mm. The gap therefore has an important bearing on the family of adhesives that will be best suited for the application.
If the gap between two cylindrical parts is very small (<0.05 mm) then it is unlikely that an epoxy will be suitable as it will probably be too high in viscosity and will be pushed out of the joint as the parts are assembled, resulting in joint starvation. In this case a low-viscosity cyanoacrylate or UV adhesive that will capillary down into the interstitial spaces may be better suited.
The optimum gap for most adhesive applications for engineering plastics is between 0.05 mm and 0.2 mm but sometimes a thicker joint with a flexible adhesive is the best solution, especially if there are high peel loads or the adhesive is acting primarily as a sealant and not as an adhesive (see Section 1.5).
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