Forever seals are a manufacturer specialized in developing and producing oil seals, o-rings and hydraulic seals. The materials include NBR, FKM, PTFE, PU, silicone, EPDM, FFKM, HNBR and so on. The materials description is below.
NBR is a kind of synthetic rubber which produced by low temperature emulsion polymerization method of butadiene and acrylonitrile, it has excellent oil resistance, wear resistance, water resistance, air tightness and good bonding properties. NBR used in the range of -30 ℃ ~ +100 ℃, the service life will decreases when it is used at 120 ℃. It is widely used in the production of a variety of oil-resistant rubber products, O-Ring, washers, casing, cable plastic materials, etc. it is also an essential elastic material in the automotive, aviation, oil and other industries.
The disadvantages of NBR are poor low temperature resistance, ozone resistance, insulation performance.
FKM rubber is a synthetic rubber that containing with fluorine atom. It has the characteristics of high temperature resistance, oil resistance, medium resistance, and variety of chemical erosion resistance. And it has high chemical stability, which has the best performance for media resistant in one of the the elastomer at present. The application for temperature ranges are from -20℃ to +200℃. The low temperature ranges are from -15℃ to -20℃ for dynamic sealing. It’s mainly used for producing oil seals, O-Rings, back up rings, O-Ring cords, rubber sheets, seal rings and so on. The disadvantages of FKM is poor performance for low temperature resistance and density is large.
PTFE has excellent chemical stability and self lubrication, the melting point of PTFE is 327 ℃, density is 2.18 ~ 2.3g/cm³, and shore hardness is D50 to D65, it is the most widely used and the most variety of fluorine plastics. It has excellent overall performance. For example, resistant to high and low temperature, corrosion resistance, aging resistance, non adhesion, high insulation, high lubrication, no poison. However, PTFE has poor creep resistance, poor wear resistance, and large expansion coefficient. Therefore, it is usually necessary to overcome these defects by filling and modifying. Commonly used fillers are bronze, carbon fiber, glass fiber, graphite, MoS2, polybenzoate, PEEK and so on. According to different conditions and uses, it can be filled with one or more of the material.
PU is a high-molecular compound. Its full name is polyurethane. It has good physical and mechanical properties, oil resistance and wear resistance. It can used for hard working conditions and avoid the dust well. It is the most commonly used in middle and high pressure hydraulic cylinder.