The so-called curing is through the solvent evaporation, melt cooling, emulsion polymerization and other physical effects, or through condensation, polymerization, cross-linking, grafting and other chemical reactions, so that the glue layer into solid process.

In order to obtain the desired joint strength after hardening, it is necessary to accurately master the process and parameters of pressure, temperature and time during the curing process.

1. Curing pressure and pressure is conducive to the full infiltration of adhesive on the surface, discharge of solvent or low molecular volatiles in the adhesive layer, controlling the thickness of adhesive layer, preventing poor contact between the bonded materials caused by shrinkage, and improving the fluidity of adhesive.

Moderate pressure can control the thickness of the adhesive layer, give full play to the bonding effect of the adhesive, and ensure that there is no air hole in the adhesive layer. The amount of pressure is related to the type of adhesive and the adhesive, and the pressure is not too high for brittle materials or plastics which are easy to deform after pressure. In general, the pressure of solvent-free adhesive is smaller than that of solvent adhesive; for epoxy resin adhesive, contact pressure can be used.

2. Temperature and time curing temperature is mainly determined by the composition of the adhesive. If the curing temperature is too low, the molecular chain movement of the matrix is difficult, resulting in the low cross-linking density of the adhesive layer and incomplete curing reaction, the curing time must be increased to make the curing complete; if the temperature is too high, it will cause the loss of the glue liquid or make the rubber layer brittle. Curing temperature will reduce the bonding strength of the joint. For some adhesives which can be cured at room temperature, the crosslinking reaction can be accelerated by heating, and the curing time can be shortened.

The higher the curing temperature, the shorter the curing time; the lower the curing temperature, the longer the curing time. Table 2 shows the curing conditions and operating temperatures of several adhesives.