The application of rubber seals is often seen on mechan […]
The application of rubber seals is often seen on mechanical equipment. It is a kind of seal that can help the mechanical equipment run better. The types of rubber seals used in different equipment will also be different, such as: O-rings, V-rings, etc. So, what are the raw materials for making rubber seals, and what are the characteristics?
Rubber seals belong to rubber products, but there are many kinds of materials, depending on the working conditions, temperature, medium, pressure, dynamic seal, static seal and other conditions, then select the appropriate material. Such as: NBR nitrile rubber, HNBR hydrogenated nitrile rubber, SIL silicone rubber, VITON fluorine rubber, etc. Now let's take a look at their respective characteristics.
1. NBR nitrile rubber sealing ring:
Suitable for petroleum-based hydraulic oil, glycol-based hydraulic oil, diester-based lubricating oil, gasoline, water, silicone grease, silicone oil and other media. It is the most widely used and lowest cost rubber seal. Not suitable for polar solvents such as ketones, ozone, nitro hydrocarbons, MEK and chloroform. The general operating temperature range is -40~120 ℃.China Custom Rubber O Rings
2. HNBR hydrogenated nitrile rubber sealing ring
has excellent anti-corrosion, anti-tear and anti-compression deformation characteristics, good ozone resistance, sunlight resistance, weather resistance. Better wear resistance than nitrile rubber. It is suitable for washing machinery, automobile engine system and refrigeration system using new environmental protection refrigerant R134a. Not recommended for use in alcohols, esters or aromatic solutions. The general temperature range is -40~150 ℃.
3, SIL silicone rubber sealing ring
has excellent heat resistance, cold resistance, ozone resistance, atmospheric aging resistance. Has good insulation properties. However, the tensile strength is inferior to ordinary rubber and not oil resistant. Suitable for household appliances such as electric water heaters, electric irons, microwave ovens, etc. It is also suitable for all kinds of articles that come into contact with the human body, such as kettles and water dispensers. Not recommended for use in most concentrated solvents, oils, concentrated acids and sodium hydroxide. The general temperature range is -55~250 ℃.
4, VITON fluorine rubber sealing ring
High temperature resistance is better than silicone rubber, has excellent weather resistance, ozone resistance and chemical resistance, poor cold resistance. Resistant to most oils and solvents, especially acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils. Suitable for the sealing needs of diesel engines, fuel systems and chemical plants. Not recommended for ketones, low molecular weight esters and nitrate-containing mixtures. The general use temperature range is -20~250 ℃.
5, FLS fluorine silicone rubber sealing ring
Its performance combines the advantages of fluororubber and silicone rubber, and is resistant to oil, solvent, fuel oil, and high and low temperature. Can resist the erosion of oxygen-containing compounds, aromatic hydrocarbon-containing solvents and chlorine-containing solvents. Generally used for aviation, aerospace and military purposes. It is not recommended to be exposed to ketones and brake fluid. The general use temperature range is -50~200 ℃.
6. EPDM EPDM rubber sealing ring
has good weather resistance, ozone resistance, water resistance and chemical resistance. It can be used for alcohols and ketones, and can also be used for sealing in high temperature water vapor environment. It is suitable for bathroom equipment, car radiator and car brake system. Not recommended for food use or exposed to mineral oil. The general temperature range is -55~150 ℃.
7, CR neoprene seal
Sunlight and weather resistance are particularly good. Not afraid of refrigerants such as dichlorodifluoromethane and ammonia, it is resistant to dilute acid and silicone grease-based lubricants, but it has a large expansion in mineral oil with a low aniline point. It is easy to crystallize and harden at low temperature. It is suitable for all kinds of environments that are exposed to the atmosphere, sunlight, ozone and various sealing links that are resistant to fire and chemicals. Not recommended for use in chemicals with strong acids, nitro hydrocarbons, esters, chloroform and ketones. The general temperature range is -55~120 ℃.
8, IIR butyl rubber sealing ring
It has particularly good air tightness, good heat resistance, sunlight resistance, ozone resistance, and good insulation performance; it has good resistance to polar solvents such as alcohol, ketone, ester, etc., and can be exposed to animal and vegetable oils or oxides. Suitable for chemical resistant or vacuum equipment. Not recommended for use with petroleum solvents, kerosene or aromatic hydrocarbons. The general use temperature range is -50~110 ℃.
9, ACM acrylic rubber sealing ring
has excellent resistance to oil products, high temperature resistance and weather resistance, but the mechanical strength, compression deformation rate and water resistance are slightly worse. Generally used in automobile transmission system and power steering system. Not suitable for hot water, brake fluid, phosphate ester. The general temperature range is -25~170 ℃.
10, NR natural rubber sealing ring
has good wear resistance, elasticity, tear strength and elongation. But it is easy to aging in the air, it becomes sticky when it is heated, it swells and dissolves in mineral oil or gasoline, it is resistant to alkali but not strong acid. It is suitable for use in liquids with hydroxide ions such as automobile brake fluid and ethanol. The general operating temperature range is -20~100 ℃.
11, PU polyurethane rubber sealing ring
Polyurethane rubber has very good mechanical properties, and its wear resistance and high pressure resistance are far superior to other rubbers. The aging resistance, ozone resistance and oil resistance are also quite good, but it is easily hydrolyzed at high temperature. Generally used in high-pressure and wear-resistant sealing links, such as hydraulic cylinders. The general use temperature range is -45~90 ℃.
12, metal rubber seal ring
is made of stainless steel wire, does not contain any rubber components, and has strong use characteristics. For example: keep working normally under high vacuum, high and low temperature, strong radiation, and various corrosive environments. The sealing ring skin is made of different materials such as stainless steel, copper, PTFE, etc. according to different uses. The coated metal rubber member serves as the lining core, which has the advantages of high sealing strength, good effect, and reusability. The sealing ring lining core is made of different metal wire diameters and densities, and is suitable for different pressure occasions. The general use range is -80~800℃. This kind of sealing ring is expensive because of its high cost. But good performance and wide use environment have been unanimously recognized by people.