The service life of rubber seals is usually affected by mechanical force, oxidation and ozonation. In general, the rubber seal ring becomes brittle and the fatigue crack growth is accelerated. The life of rubber seal ring will be reduced by reducing the critical fracture energy. The specific factors of rubber seal ring life mainly include the following aspects:

Aging will cause mechanical cracking reaction under the action of mechanical force: due to the viscous properties of polymer, the relaxation process of rubber in the deformation cycle is not completed yet, and then it enters the next deformation cycle, which makes the deformation residual stress of rubber seal manufacturers continuously increase. When the stress gradient is large, the use of rubber seals will lead to the direct fracture of rubber molecular chain and the formation of free radicals, which will lead to the oxidation chain reaction of rubber free radicals under the action of oxygen.

Aging will cause the oxidative cracking reaction activated by mechanical force: when the rubber sealing ring is repeatedly deformed in the sealing process, its mechanical stress will weaken the atomic valence force in the rubber molecular chain, thus reducing its oxidation reaction activation energy. The decrease of oxidation activation energy makes the oxidative cracking of rubber molecular chain easier and accelerates.

The internal heat generation of rubber seal ring accelerates the oxidation reaction: the storage mode of rubber seal will produce lag phenomenon when repeated deformation, and cause internal friction, so as to make rubber internal heat generation, which further accelerates the oxidation chain reaction and aging of rubber.

Ozone cracking of rubber seal ring: during the aging process of periodic deformation of rubber seal ring, ozone cracking phenomenon appears, which is more significant under high temperature conditions.