Aging of O-rings

O-Ring Aging ProblemIn general, O-ring aging is related to 4 factors:

1. Ozone: The chemical activity of ozone is much higher than that of oxygen, and the destructive force is greater, it is the same molecular chain break, but the effect of ozone on rubber has or no rubber deformation. When acting on deformed rubber (mainly unsaturated rubber), there is a crack in the direction of stress action, called "ozone crack", which only forms an oxide film on the surface without cracking when acting on deformed rubber.

2. Light: We all know that the shorter the light wave, the greater the energy. The damage to silicone rubber miscellaneous parts is high-energy ultraviolet rays, which can not only directly cause the fracture and cross-linking of rubber molecular chains, but also cause free radicals to be produced by rubber due to light energy absorption, thereby triggering and accelerating the oxidation chain reaction process. Secondly, direct sunlight will act as heating through the outside light. Another characteristic of light utilization is that it grows mainly on the surface of oak trees.

3. Oxygen: Oxygen undergoes a free radical chain reaction with the molecular structure of rubber in rubber, and the molecular chain is broken or excessively cross-linked, causing changes in the properties of rubber materials. Oxidation is one of the important causes of rubber aging.

4. Heat: The increase in temperature will cause thermal cracking or thermal cross-linking of rubber.