Polyurethane has emerged as one of the most versatile seal material. Apart from its high wear resistance characteristics compared to other materials it possesses elastic qualities of rubber.The flexibility in chemically engineering TPU’s to get a wide range of properties including fluid and moisture resistance has led to a wide acceptance of this material. Polyurethane seals offer outstanding performance in high pressure hydraulic systems with abrasive contamination,high shock loads, and related adverse conditions at temperature's upto 120°C.

Polyester and Polyether grade of PUR are generally used in the seal industry. Polyester grades generally have superior mechanical properties whereas Polyether grades have better chemical and hydrolytic stability. Special polyurethane materials having good low temperature behavior are being designed and used for specific applications.