What Are The Reasons For The Aging Of Rubber Seals?
The rubber sealing ring is made of rubber material, so what is the reason for the aging of the rubber sealing ring? In the production process of rubber seals, due to the comprehensive action of internal and external factors, the physical and chemical properties and mechanical properties of the rubber are gradually deteriorated, resulting in loss of use value. This change is called rubber aging. The surface shows cracks, stickiness, hardening, softening, chalking, discoloration, mildew and so on. So, what are the specific factors?
The increase in temperature leads to the cracking of the rubber material of the sealing ring, resulting in a chemical oxidation reaction and accelerating the rate of the rubber oxidation reaction.
The shorter the light wave, the greater the energy. The damage to the rubber seal ring is the higher energy ultraviolet rays. In addition to the direct rupture and cross-linking of the rubber molecular chain caused by ultraviolet rays, the rubber of the rubber seal ring generates free radicals due to the absorption of light energy, which initiates and accelerates the oxidation chain reaction process.
Oxygen undergoes free radical chain reaction with rubber molecules in the rubber, and the molecular chain is broken or excessively cross-linked, which causes the change of the performance of the rubber sealing ring. Oxidation is one of the important reasons for rubber aging.
The chemically active oxygen of ozone is much higher and it is more destructive. It also breaks the molecular chain, but the effect of ozone on rubber varies with the deformation of the rubber sealing ring.
The rubber seal ring is easily damaged when it is exposed to rain or immersed in water. This is because the water-soluble substances in the rubber and components such as clear water are extracted and dissolved by water.
F. Mechanical stress
Under the repeated action of mechanical stress, the molecular chain of the rubber seal ring will be broken to form free radicals, which will trigger the oxidation chain reaction, which will easily cause ozone cracking under the action of stress.