Three key parameters of adhesive
Three key parameters of the adhesive must be considered: working life (or the time between the two). Mix the adhesive and close the joint), the time to handle the strength (the time it takes for the glue to self-fix to allow further processing) and the final curing time (time). The adhesive has basically reached the level of final curing). These times depend on the chemistry and specific formulation of the adhesive, as well as the environment or application temperature.
The application process of the actual structural adhesive is quite fast compared with welding. The structural adhesive itself needs a fixed cycle, and sufficient strength is developed to allow the adhesive to work. Understand further stress during the processing of downstream parts. At room temperature, this time may be as short as 15 minutes or as long as several hours. This time can be shortened by the application. Regarding heat (induction therapy or heating lamps, guns or blankets are large pieces; or ovens are smaller parts). This time can also be chemically controlled to provide a specific processing time. Add N, and once the two-component adhesive is mixed, it begins to cure or "gel".
There is a finite amount of time between mixing, and then, when the two surfaces to be joined must be mated. If the adhesive is in a mixed state that is too long before mating the surface, the adhesive will not form "wet out" due to excessive gelation, that is, it will not be in full close contact with the surface and will Greatly reduce the final bond strength.
Finally, the two-part adhesive is cured by a chemical reaction; not by drying (as in contact with the adhesive) or cooling (as in hot melt). At higher temperatures, the chemical reaction occurs faster than at l. OWER temperature. Therefore, when designing the production process, the temperature of the production equipment and the substrate to be bonded should be considered. If the temperature changes significantly, (for example, from winter to summer), the production process may need to be changed, or the adhesive used may need to be changed.