Sikaflex, one-part polyurethane sealants and adhesives cure on exposure to atmospheric moisture to form a durable elastomer. One-component Sikaflex PUR products exhibit excellent adhesive properties and a high degree of mechanical strength once the curing process is concluded.
The chemical reaction of one-component Sikaflex PUR products requires some precautions as far as the handling and the curing time is concerned.
The handling and curing time will vary with each type of application on board and the loads involved.
Open Time The open time is the time the adhesive can be left before the skinning of the adhesive starts to interfere with the adhesion.
Handling Time Handling time and time to full load are determined not only by the stresses involved, but also by the access of moisture, as Sikaflex products cure by way of moisture diffusion from the outside inward into the adhesive bead. The speed of cure and strength development can be significantly influenced by the design of the joint, the porosity of the substrate(s), the absolute humidity in the air, the ambient temperature and the temperature of the substrate.
Cure Time The cure time is considered the time span required for the adhesive to cure until full load can be applied to the finished part.
