What are the materials of the sealing lip to choose from?
Sealing lips are available in a variety of materials to meet the requirements of different working environments and media. Here are some common sealing lip materials and their properties:
Rubber-like material
Nitrile rubber (NBR)
It has excellent oil resistance and can be used in the temperature range of -55°C~100°C.
It has good abrasion resistance and acid and alkali resistance and is suitable for a variety of industrial environments.
Fluoroelastomer (FKM/FPM)
It has excellent high-temperature resistance and can maintain stable performance in environments up to 230°C.
It has strong medium resistance, good compression deformation resistance, flame retardant, and air permeability, and is suitable for occasions with high temperature, ozone resistance, and weather resistance.
Silicone rubber (VMQ)
Heat-resistant polymer materials, a wide range of operating temperatures, generally -100°C~300°C.
Excellent electrical insulation and anti-aging performance, which can meet the requirements of food grade and is suitable for a variety of special occasions.
Acrylic rubber (ACM)
Good oil resistance, similar to nitrile.
The tensile strength, hardness change, and other physical properties at room temperature are better than those of nitrile rubber, and the service temperature is generally -50 °C ~ 180 °C.
Polyurethane (PU)
It has good abrasion resistance, elasticity, and tear strength.
It has good oil resistance, solvent resistance, and aging resistance, and is suitable for a variety of dynamic sealing occasions.
Plastics and composites
Ultra-high molecular weight polyethylene (UHMWPE)
It has excellent abrasion resistance, and the applicable temperature is -160°C~+100°C.
It is typically used in water and low-temperature applications and has a long service life.
Polytetrafluoroethylene (PTFE)
Resistant to almost all hydraulic media, solvents, and various chemical media.
With a low coefficient of friction and no creeping, it is suitable for use in industries such as food, beverage, and pharmaceutical.
Chemical resistance and abrasion resistance can be improved by adding additives such as carbon fiber.
Other materials
Metal
Such as steel, brass, etc., used in sealing occasions that require high strength and high-temperature resistance.
However, metal sealing lips often need to be used in combination with rubber or other elastomeric materials to improve sealing performance and abrasion resistance.
Ceramic
It has extremely high hardness and wear resistance and is suitable for high temperature, high pressure, and highly corrosive occasions.
However, ceramic sealing lips are expensive to process and install, and are fragile, so their applications are relatively limited.
In summary, the material selection of the sealing lip should be comprehensively considered according to the specific working environment, media requirements, temperature range, pressure rating, cost, and other factors. When choosing, it is recommended to consult a professional seal manufacturer or supplier for more accurate advice and technical support.
