O-ring O-ring (O-rings) is a circular cross-section rubber seal, O-shaped cross-section because, so called O-shaped rubber ring, also known as O-rings. Began to appear in the mid-19th century, the steam engine cylinder seal member was using it for.
Because they are inexpensive, simple to manufacture and reliable function and simple installation requirements, O-ring seals are the most common mechanical design. O-rings withstand tens of Pascal (thousands of pounds) of pressure. O-rings for static applications, can also be used in dynamic applications between member relative motion, such as a rotary pump shaft and cylinder piston.
O-ring material selection:
Natural rubber NR (Natural Rubber) made of latex from the rubber tree collection, isoprene polymer. It has good abrasion resistance, high elasticity, tensile strength and elongation. Easy to aging in the air, when heated, becomes sticky, easy expansion and dissolved in mineral oil or gasoline, but not resistant to strong acid and alkali. · Is making belts, hoses, rubber raw materials, and for the production of shock absorber parts, used in the liquid with a hydroxyl automotive brake fluid, ethanol and other products.
EPDM rubber EPDM (Ethylene propylene Rubber) by the co-polymerization of ethylene and propylene backbone substandard double-stranded, and therefore heat resistance, aging resistance, ozone resistance, stability are very good, but can not sulfur, and sulfur. To solve this problem, the EP main chain into a small amount of a third component of the double-stranded and can be sulfur and sulfur Serve EPDM, the general temperature range of -50 ~ 150 ℃. Polar solvents such as alcohols, ketones, glycol lipids, and
· With good anti-designate and ozone resistance
· Has excellent water resistance and resistance to chemicals
• You can use alcohols and ketones
· High temperature steam with good gas impermeability
* Not recommended for food use or being exposed to aromatic hydrogen. High temperature steam seals the environment.
· Sanitary equipment seals or parts.
Brake (Brake) system rubber parts.
· Radiator (Radiator) of seals.
NBR NBR (Nitrile Rubber) by the polymerization of acrylonitrile and butadiene, acrylonitrile content from 18% to 50%, the higher the acrylonitrile content, resistance to petrochemical oil hydrocarbon fuel the better, However, low temperature performance is poor, the general temperature range of -25 ~ 100 ℃. NBR is one of the most commonly used rubber seals and O-rings present.
· With good resistance to oil, water resistance, solvent resistance and resistance to high pressure oil properties.
· With good compression distortion, wear and elongation force.
· Not suitable for polar solvents being, such as ketones, ozone, nitro hydrocarbons, MEK and chloroform. · For the production of the fuel tank, oil tank and lubricating oil in the oil-based hydraulic oil, gasoline, water, silicone grease, silicone, titanium esters, glycol-based hydraulic fluid medium oil used in rubber parts, especially the sealing parts . It can be said is the most widely used and lowest cost rubber seals.
Silastic SI (Silicone Rubber) a main chain composed of silicon (-si-o-si) a combination. It has excellent heat resistance, cold resistance, ozone resistance, resistance to atmospheric aging. It has good electrical insulation properties. Tensile strength than ordinary rubber difference without having oil resistance. advantage:
· After modulation formula tensile strength and tear resistance of up to up to 1500PSI 88LBS
· Good flexibility and good compressibility
· Neutral solvent has good resistance
· With excellent heat resistance
· With excellent cold resistance
• For ozone and oxides with excellent corrosion resistance
· Excellent electrical insulation properties
· Insulation, good heat dissipation
* Not recommended for use in most concentrated solvents, oils, concentrated acid and sodium hydroxide after being diluted. · Used by the household appliances industry seals or rubber parts, such as electric kettle, electric iron, rubber parts inside the microwave oven.
· Electronics industry seals or rubber parts, such as the phone keypad, DVD inside the cushion, cable seal joints within the like.
· Seal with the human body in contact with all kinds of items on such as water bottles, drinking fountains and the like.
Viton FPM (Fluoro Carbon Rubber) of intramolecular fluorine rubber, according to the fluoride content (ie monomeric building) and there are various types. Series Six fluoride fluorine rubber currently the most widely used first by the DuPont Company to "Viton" tradename market. High temperature resistance than silicone rubber, has excellent chemical resistance, resistance to most oils and solvents (ketones, esters, except), weather resistance and ozone resistance; cold is relatively poor, the general temperature range of -20 ~ 250 ℃. Specially formulated to be low temperature -40 ℃.
• You can heat to 250 ℃
• For most of the oil and solvent have the ability to resist, especially all of the acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils
* Not recommended for use in ketones, low molecular weight esters and a mixture containing nitrate. * Automobiles, motorcycles, diesel engines and fuel systems.
· Chemical seals.
Polyurethane PU (Urethane Rubber) very good mechanical properties, high hardness, high elasticity, abrasion resistance are difficult compared to other rubber class; resistance to aging, ozone resistance, oil resistance is also quite good. General temperature range of -45 ~ 90 ℃.
· Wear resistance, high pressure
· Not high temperature high pressure resistance, wear-resistant seals, such as hydraulic cylinder seals · on the industry.
High-pressure charge system