How to choose a polyurethane O-ring?

The selection of the sealing material of the polyurethane O-ring is of great significance to its sealing performance and service life. The function of the material directly affects the function of the O-ring. In addition to the general requirements for sealing ring materials, O-rings should also pay attention to the following conditions:
(1) Elasticity and resilience;
(2) Appropriate mechanical strength, including expansion strength, elongation and tear strength.
(3) The function is stable, it is not easy to swell in the medium, and the thermal shrinkage effect (Joule effect) is small.
(4) It is easy to process and form, and can adhere to fine dimensions.
(5) Does not corrode the contact surface, does not pollute the medium, etc.

Rubber is one of the more suitable and commonly used raw materials that can meet the above requirements, so O-rings are mostly made of rubber materials. There are many varieties of rubber, and new varieties of rubber appear constantly. When designing and selecting, you should understand the characteristics of various rubbers and choose them reasonably.