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Name
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Code
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Characteristics
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Temperature(℃)
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Application
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Nitrile - Butadiene Rubber
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NBR
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Good mechanical technological parameters,e.g. high abrasion resistance, low gas permeability and good resistance to mineral oil based lubricating oils and greases, hydraulic oils,highlynon-flammable hydraulic fluids HFA, HFB, HFC, silicone oils and greases, water up to approx. 80°C.NBR is generally not resistant to polar solvents, glycol-based brake fluids and highly non-flammable hydraulic fluids HFD. It has a low resistance to ozone, weathering and ageing. In most hydraulic applications this has no effect because the hydraulicseals are installed internally in the hydraulic components.
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-30/+120
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NBR is frequently used in the hydraulic field due to its good mechanical characteristics and resistance to mineral oil based lubricating oils and greases.
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Fluoroel astomer
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FKM
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FKM is a fluorocarbon elastomer with high thermal and chemical resistance.Its broad spectrum of resistance and relatively good compression set, even at high temperatures.
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-20/+200
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FKM is known especially for its non-flammability, low gas permeability and excellent resistance to ozone, weathering and aging.
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Polyurethane
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PU
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PU materials display higher mechanical strength,high abrasion, wear and extrusion resistance, high pressure load capacity,as well as a high tear and elongation at break resistance. Also have good flexibility and very good ageing and ozone resistance.
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-45+110
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PU materials are suitable for application in mineral oils and greases,hydraulic oils, silicone oils and greases, highly non-flammable hydraulic fluids HFA and HFB and water up to 50°.
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Fabric Reinforcement Rubber
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FAB
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Have high wear resistance, good low temperature resistance and high pressure load and extrusion resistance. In addition rubber fabric hydraulic seals are inherently very dimensionally stable and have a low moisture expansion tendency in hydraulic media.
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-30/+100
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Particularly well suited for rough application conditions, such as in mobile hydraulics or other heavy duty applications.
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Silicone Rubber
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VMQ
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VMQshows excellent heat resistance, cold flexibility,dielectric properties and especially good resistance to weather, ozone and UV rays.Not suitable for oil based fluid.
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-60/+230
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Foodstuff and cryogenic engineering.
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Polyacrylate Rubber
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ACM
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ACM shows excellent resistance to ozone, weathering and hot air, although it shows only a medium physical strength,low elasticity and a relatively limited low temperature capability.
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-20/+150
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ACM materials are mainly used in automotive applications which require special resistance to lubricants containing many additives (incl. sulfur) at high temperatures.
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Ethylene Propylene Diene Rubber
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EPDM
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EPDM shows good heat, ozone and aging resistance. In addition they also exhibit high levels of elasticity, good low temperature behavior as well as good insulating properties
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-50/+150
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EPDM can often be found in applications with brake fluids (based on glycol) and hot water.
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Hydrogenated Nitrile Butadiene Rubber
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HNBR
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HNBR shows good mechanical properties.The operating temperature of HNBR ranges between -30°C and +140°C(for a short period of time up to +160°C) in contact with mineral oils.Special types can be used down to -40°C.
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-30/+140
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Mainly use in mineral oil at high temperature.
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Chloroprene Rubber
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CR
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In general the CR materials show relatively good resistances to ozone, weathering, chemicals and aging.Also they show good non-flammability, good mechanical properties and cold flexibility.
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-30～+100
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CR materials are found in sealing applications such as refrigerants, for outdoor applications.
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Polytetrafluor oethylene
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PTFE
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PTFE display almost universal chemical resistance,an extremely low friction value which results in very good sliding characteristics, no stick-slip effect,particular rigidity and almost unlimited ozone, weathering and ageing resistance. PTFE is impervious to almost all known hydraulic media, lubricants,chemicals and solvents.PTFE is non-flammable and so does not constitute an additional hazard in case of fire.Pure PTFE is not totally without disadvantages as it has a tendency to cold flow or crawl under pressure load.These weaknesses are counteracted by the use of seal compounds mixed with fillers.
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-55～+260
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Pure PTFE is particularly suitable for food and beverage applications, pharmaceuticals and medical application areas. PTFE is not or only slightly elastic. For this reason, PTFE seal elements are activated by elastic energising elements in the form of o-rings or stainless steel springs. Compounds filled with bronze for example, give PTFE the ability to adapt to most application conditions.
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Nylon
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PA
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PA has a good wear resistance.Water absorption and resulting change in volume can be catered for by increasing housing tolerances.
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-40～+120
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PA is a high-molecular polyamide from which even large elements can be produced economically,is used for large bearings and support rings.
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Polyoxymethyl ene
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POM
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Excellent sliding characteristics, particularly in the dry-running range of the bearing element.The material is tough and maintains good stability of shape at different temperatures. Its chemical structure also gives it high resistance to various fluids with low water absorbtion.
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-40～+140
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Particularly suitable for the functions which guide rings and back-up rings are required to fulfil.
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Utra High Molecular Weight Polyethylene
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UHMW-PE
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Excellent wear and abrasion resistance.
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-160~ +100
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Best in aqueous solutions and cryogenic temperatures.
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Phenolic Resin with Fabric Reinforcement
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HG
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With the selection of the optimal material combinations (fabric/resin), a long product life, high restoring force, low friction and very high contact pressure (load capacity) can be achieved. No moisture expansion in water; or measurable absorption of water.
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-60…+120
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Selected for application areas in hydraulics with high loads and shear forces,heavry duty wear ring for example.
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