O-ring seals are widely used in the sealing of various mechanical equipment. At specific temperatures, pressures and different liquid and gas media, it plays a sealing role in static or moving states, and has high and low temperature resistance. Delong product experts introduced that when using silicone seal products, it is necessary to control the ambient temperature, maintain good sealing elasticity, and the advantages of ozone resistance and weather-resistant aging.
Secondly, the silicone sealing ring in the rubber sealing ring material has the excellent characteristics of non-toxic, tasteless, waterproof, flame retardant, heat resistance, wear resistance, oil resistance, etc. It can be made into thermal insulation, insulation products and medical silicone products, which is the standard seal of environmental protection level. So, what is the aging factor of O-type rubber seal material?
1, the principle of oxidation oxygen in the O-type rubber sealing ring material and rubber molecules free base chain reaction, molecular chain break or crosslinking too much, resulting in changes in the characteristics of silicone rubber products. Oxidation reaction is one of the important reasons for rubber seal aging.
2, the light principle of destroying the rubber seal material is the higher energy of the ultraviolet, because the shorter the light wave, the greater the energy. In addition to causing the breakdown and crosslinking of rubber molecular chains, rubber also produces free groups due to the absorption of light energy, thus accelerating the reaction process of the oxidation chain. External light acts as heating. Another characteristic of light action (unlike heat action) is that it mainly enters the rubber surface. For samples with high adhesive content, there will be a mesh crack on both sides, the so-called "photoouter crack".
3, the role of ozone ozone chemical reactive oxygen species is much higher, more destructive. It also destroys molecular chains, but the effect of ozone on O-ring materials varies with rubber deformation.
4, high temperature rise temperature will lead to thermal cracking or thermal crosslinking of O-type rubber seal products, but the main role of heat is activation. Increasing the oxygen diffusion rate and active oxidation reaction and accelerating the rubber oxidation reaction rate is a common aging situation, that is, hot oxygen aging.
5, under the repeated action of mechanical stress, mechanical stress will break the molecular chain of the rubber seal ring, produce free tsuen, cause oxidation chain reaction, and form a mechanochemical process. Mechanical molecular chain breaking and mechanical activation oxidation process. Secondly, it is easy to cause ozone cracking under the action of stress.
6, the role of water lies in two aspects. First, silicone rubber products are easy to damage when wet gas rains or soaked in water. This is because the water-soluble substances in rubber and water tsuen are dissolved by water extraction. The second is hydrolysis or absorption, especially under the alternating influence of water immersion and atmospheric exposure, which will accelerate the damage of rubber sealing materials.
Seven, chemical media (oil) and other reasons, variable metal ions, high-energy radiation, electricity and biology will also affect the aging level of O-type rubber sealing materials.