There are many materials for rubber seals, and here are some of the most common ones:
Natural Rubber (NR)
Characteristics
It has good elasticity, tensile strength, and abrasion resistance. At room temperature, natural rubber has a high elasticity and can withstand deformation without damage to a certain extent, which makes it able to effectively fill the sealing gap in the seal and achieve a good sealing effect.
It has a certain tolerance to weak acids and bases in general. For example, in some environments with moderate pH, natural rubber seals can work without being quickly corroded.
It has good processing performance is easy to form, and can be made into seals of various shapes and sizes to meet the sealing needs of different equipment.
Application Scenarios
It is often used in general mechanical seals, plumbing pipe seals, etc. In these scenarios, the working environment is relatively mild and the performance requirements for the seals are not particularly demanding. For example, faucet seals in the home, static seals of some small mechanical devices, etc.
Nitrile rubber (NBR)
Characteristics
It has excellent oil resistance and good resistance to petroleum products, lubricating oils, etc. This is because the molecular structure of nitrile rubber contains polar groups that can interact with oil molecules, thereby reducing the erosion of rubber by oil.
It also has good abrasion resistance, heat resistance, and aging resistance. At higher temperatures, nitrile seals can still maintain some elasticity and sealing properties and can resist friction and wear, extending service life.
Formulations can be adjusted to meet different performance requirements according to different needs. For example, the acrylonitrile content in nitrile rubber can be changed to adjust its oil resistance, hardness, elasticity, and other performance indicators.
Application Scenarios
They are widely used in automotive, petrochemical, aerospace, and seals. For example, oil seals for automobile engines, seals for hydraulic systems, joint seals for oil pipelines, etc.
Silicone Rubber (VMQ)
Characteristics
It has extremely high heat and cold resistance and can maintain good elasticity and sealing properties over a wide temperature range. Silicone rubber seals, for example, can work well in temperatures ranging from -60°C to 250°C.
It has excellent electrical insulation performance and has a good insulation effect on high-voltage and high-frequency signals. This makes silicone rubber seals widely used in the field of electronic appliances.
Physiologically inert, non-toxic, and tasteless, non-irritating to human tissues, so it is also suitable for seals in medical, food, and other industries.
Application Scenarios
It was sealing in high-temperature environments, such as door sealing of ovens, microwave ovens, and other equipment. In the field of electronic appliances, it is used to seal electronic components, cable joints, etc. In the medical industry, it is used for the sealing of medical devices, such as syringes, infusion tubes, etc.
Fluoroelastomer (FKM)
Characteristics
It has excellent corrosion resistance and strong resistance to strong acids, strong alkalis, organic solvents, etc. This is because fluoroelastomers contain fluorine atoms in their molecular structure, which makes them chemically stable.
Excellent high-temperature resistance can operate at high temperatures from 200°C to 250°C for a long time. In a high-temperature environment, fluoroelastomer seals can still maintain good elasticity and sealing performance, and will not be softened, deformed, or lose sealing ability due to high temperatures.
It has low air permeability and water absorption, which can effectively prevent the penetration of gases and liquids.
Application Scenarios
Seals are commonly used in high-temperature and strong corrosive environments in chemical, aerospace, automotive, and other fields. For example, valve seals for chemical equipment, oil seals for aero engines, seals for automotive fuel systems, etc.
Ethylene propylene diene monomer (EPDM)
Characteristics
It has good aging resistance, ozone resistance, and weather resistance. When used outdoors for a long time, ethylene propylene rubber seals do not easily age and crack due to ultraviolet rays, ozone, and other factors, and can maintain sealing performance for a long time.
It has good barrier properties for water and water vapor, and can effectively prevent the penetration of moisture. At the same time, ethylene propylene rubber also has good electrical insulation properties.
It has a low cost and is relatively cheap.
Application Scenarios
It is widely used in seals in construction, automotive, electrical, and other fields. For example, the sealing of building doors and windows, the sealing of automobile water tanks, the sealing of wires and cables, etc.
