O-rings processing technology
O - type ring is a kind of sealed product with simple structure, a wide range of specifications and a large amount of demand.
The seal quality life of o-ring depends on dimension precision and glue. General requirements rubber has certain mechanical strength, tear resistance and good heat resistance, oil resistance, resistance to chemical media and under the conditions of use to so low compression permanent deformation, is the main index.
According to the use requirement, generally have the requirement of heat resistance and oil resistance, the use of glue is the most butyronitonitrile.
The high temperature required (such as 150 ~ C - l90 ℃) can use acrylate rubber oil seal products. High temperature resistant rubber products are used with fluorine rubber and silicone rubber.
At high working pressure, increase O-rings rubber hardness method is to increase in the volume of carbon black filled, but the amount of fill, mixing, and basic physical property damage vulcanizates, also make the rubber scorch easily occur.
In the case of using the same rubber, such as nitrile rubber, to improve the heat resistance and oil resistance, reduce the compression permanent deformation, can use peroxide vulcanization system (such as the use of DCP) or effective sulfur curing system (low sulfur and high promotion). The two sulfide systems can produce more carbon one-carbon bonded crosslinking structure and single sulfur bonding structure, effectively improve the heat resistance and oil resistance of vulcanized rubber, and reduce the compression permanent deformation.
O-rings, heat resistant, oil resistant rubber material in the formula of the filling reinforcing system, adopt more active low cracking of carbon black, carbon black spray or half reinforcing carbon black, the characteristics of the carbon black is coarser particles, rubber has good elasticity, low heat, low compression permanent deformation, and a large number of filling, reduce the cost of rubber. If the o-ring is used in dynamic sealing condition, it needs to increase the tear resistance and can be used in high - wear carbon black.
The rubber of fluoro rubber is a self-reinforcing rubber, such as filling the reactive carbon black and reducing the mechanical properties of the rubber. Therefore, the hot crack carbon black or spray carbon black is generally filled with a small amount of low-activity coarse particles.
Consists of one or a few parts of the annular cover, fixed in a bearing ring or washer on and contact with another ring or washer or form a labyrinth of narrow gap and prevent the lubricating oil leakage and outside intrusion. O-rings is a circular rubber ring, because its cross section is O type, so it is called O-rings.
1. NBR butyronitrile rubber o-ring:
It is suitable for oil hydraulic oil, ethylene glycol oil, 2 ester lube oil, gasoline, water, silicon grease, silicon oil etc. It is the most widely used and cheapest rubber seal. It is not suitable for polar solvents, such as ketones, ozone, nitro-hydrocarbons, MEK and chloroform. General use temperature range for - 40 ~ 120 ℃.
2. HNBR hydrogenated nitrile rubber o-ring:
It has excellent anti-corrosion, anti-tear and anti-compression deformation characteristics. It is good for ozone, sunlight and weather. Butadiene rubber has better abrasion resistance. Suitable for washing machine and automobile engine system. It is not recommended for use in alcohols, esters or aromatic solutions. General use temperature range for - 40 ~ 150 ℃.
3. SIL silicone rubber o-ring:
It has excellent heat resistance, cold resistance, ozone resistance and atmospheric aging properties. It has good insulation. But the tensile strength is less than general rubber and is not oily. Applicable to household appliances such as electric water heater, electric iron, microwave oven, etc. It is also applicable to all kinds of products that have contact with the human body, such as kettle, water dispenser and so on. It is not recommended to use in most concentrated solvents, oils, concentrated acids and sodium hydroxide. General use temperature range is - 55 ~ 250 ℃.
O-rings Processing Technology
- Jul 20, 2017-