The one-component sealant sealed package is stable in the container, and it will solidify when it is exposed from the container when exposed to the air. This is a chemical reaction process. The sealant is originally a paste. After contact with air, the base rubber, crosslinker, and catalyst in the sealant chemically react with the water in the air. The result of this chemical reaction is to make This paste gradually becomes an elastic solid, which is the curing of the sealant. After the sealant is punched out, because the first contact with water is the surface of the sealant, it is the surface that cures first. After the surface is cured, the moisture penetrates into the surface that has been cured, and the inner layer is re-cured. The sealant is gradually cured from the surface to the interior. The longer the time, the thicker the solidification. The thicker the sealant, the longer it takes to fully cure. For example, a 10mm thick adhesive usually takes more than a week to fully cure.

The two-component sealant is carried out through a chemical reaction between components A and B. The A and B components are stable and stored separately. Once the A and B components are mixed, they begin to react, so the A and B components should be used immediately after mixing. The two-component curing reaction does not require water in the air to participate, so its curing is carried out at the same time as the interior and the surface. The complete curing time is independent of the thickness of the glue, so the reaction is not related to whether it is exposed to air. Component B is mixed together and will cure even in a closed state.

The following are several concepts of sealant curing performance:
Surface dry: The sealant is paste-like when it comes out. When it touches its surface with fingers or other materials, the glue will adhere to the fingers or materials. After the sealant comes out, the surface contacts the moisture to begin to solidify the skin. When the skin is formed, the finger or material is used to touch the surface, and no glue will adhere to the finger or material. This is called surface drying.

Surface drying time: The sealant is taken out of the container to start counting, and the time required to dry it is the surface drying time.

Degreasing: After the sealant dries, touch the surface with your fingers. Although there is no glue sticking to the fingers, you can still feel a certain degree of adhesion between the glue surface and the fingers. This phenomenon we call No tackiness. This is because the curing reaction of the glue surface has not yet fully manifested. Over time, it will further solidify until the surface forms a layer of skin with a certain elasticity and strength. It feels dry with the touch of fingers, and there is no feeling of adhesion, which we call degreasing.

Tack-free time: The time it takes for the sealant to come out of the container and the time required to tack the surface is the tack-free time.