Classification of polyurethane sealants

Polyurethane sealants are generally classified into two basic types: single-component and two-component. Single-component sealants are moisture-curing, while two-component sealants are reaction-curing. Single-component sealants are easy to apply but cure more slowly; two-component sealants cure quickly and have better performance, but require mixing before use, making the process more complex. Both have their future prospects.

Based on their flowability, polyurethane sealants can be further divided into non-sagging and self-leveling types. Non-sagging sealants are used on vertical surfaces, inclined surfaces, ceilings, etc., and will not shift, slide, or flow due to their own weight before curing; while self-leveling sealants are specifically used for horizontal applications. Based on their post-application properties, they can also be classified as non-drying, semi-drying, and fully cured elastomer types.