Views: 2464 Author: Site Editor Publish Time: 2020-07-29 Origin: Site
O-ring is a common seal, which is widely used in a variety of seals, such as non contacting mechanical seal, spring seal, pump seal, gland packing, elastomer bellows seal, etc. Because of its wide application, there are many kinds of materials used to make O-rings, which makes people do not know how to choose. The following content introduces the advantages and disadvantages of O-rings made of various materials, which can let you choose the most suitable O-rings.
Natural rubber is made of latex collected from rubber tree, which is isoprene polymer. It has good wear resistance, high elasticity, breaking strength and elongation. However, it is easy to age in the air, it will become sticky when exposed to high temperature, and it is easy to expand and dissolve in mineral oil or gasoline. It has alkali resistance but not acid resistance. It is the raw material for making adhesive tape, rubber hose and rubber shoes, and is suitable for making shock absorption parts.
SBR is a copolymer of butadiene and styrene. Compared with natural rubber, it has the characteristics of uniform quality and less foreign matters. However, its mechanical strength is weak. SBR is a low cost non oil resistant material with good water resistance. Most neutral chemicals will not damage it, but strong acids, ozone, oil will damage it. It is widely used in tire industry, shoe industry and conveyor belt industry.
Butyl rubber is polymerized from isobutylene and a small amount of isoprene. This kind of material is not easy to be penetrated by gas, has great resistance to heat, sunlight and ozone, and has good electrical insulation. It is resistant to polar solvents such as alcohols, ketones, esters and so on. Generally, its use temperature range is -54℃to 110℃. However, Petroleum solvents, kerosene and aromatics can destroy its structure. It is mainly used for making rubber parts of vacuum equipment.
Hydrogenated nitrile rubber is made of nitrile rubber by hydrogenation. Its temperature resistance and weather resistance are much higher than that of nitrile rubber, and its oil resistance is similar to that of nitrile rubber. Its use temperature range is -25℃ to 150℃. It has better wear resistance than nitrile rubber and has excellent corrosion resistance. It also has good resistance to ozone and sunlight. It can be used to manufacture seals for automotive engine systems.
Ethylene propylene rubber is produced by copolymerization of ethylene and propylene, so it has excellent heat resistance, aging resistance, ozone resistance and stability. It has good weather resistance, water resistance and chemical stability. It has good resistance to ozone and polar solvents. It is not easy to be penetrated by gas and can withstand the erosion of high temperature water vapor. It is mainly used to make seals in high temperature water vapor environment, seals of sanitary equipment, rubber parts in automobile brake system and seals of automobile radiator.