With the polyurethane sealant widely used nowadays, more and more people hold an objective assessment for it. On the whole, polyurethane sealant enables to be applied in the many aspects so as to meet the daily production requirements. However, its demerits are also obvious.
The characteristics of polyurethane sealant are as follow: good abrasive resistance, low temperature flexibility, wide performance adjustments, good mechanical strength, excellent bonding strength and elasticity, the ability to recover, fit for the dynamic joint, weather proof, long working life (15-20 years), good oil resistance, excellent biological aging resistance and the reasonable price.
But there are some demerits as below: not be resistant to heat for a long time, the light color formulation that is easy to become aging with exposure to UV, the storage stability of one component sealant apt to be affected by the package and outside world, slow cure speed, may produce bubbles and flaws in the high temperature and humid environment, indispensable primer in many applications.
Every coin has two sides, and the polyurethane sealant is not an exception. Even though it has many demerits, the adhesives filed always makes great efforts to innovate and improve it, for example, Dow Corning,3M and Loctite are three international manufactures made contributions to this sealant. We believe the application of polyurethane will become more mature and perfect in the future.