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Buna-N O-rings Special Compounds

Special Compounds in NBR Buna-N Nitrile O-Rings - Delivery Times from Stock to 12 weeks.

Nitrile rubber — also known as acrylonitrile butadiene rubber, NBR, or Buna-N — is a synthetically produced, petroleum-based rubber ideal for seals, gaskets and o-rings. Nitrile is a highly versatile rubber. It is used in countless applications and products, from marine fuel systems to small engine carburetors. Buna-N is currently one of the most widely used elastomers in the manufacture of seals.

While Nitrile rubber is considered to be a general purpose material for O-Rings and many other seals, it can be specifically compounded for many purposes.  Grades are available for: food processing, use with milk and edible oils, potable water and other specialty applications. Internal lubricants may be added to reduce frictional properties and extend wear. Specialty Nitrile polymers can be produced by carboxylation or hydrogenation HNBR.

NBR (acrylonitrile-butadiene-rubber) is a polymer of butadiene and acrylonitrile (ACN). The proportion of acrylonitrile can be between 18% and 50% and signifcantly affects the properties of the polymer. Thus, an NBR with a low acrylonitrile content is characterized by a very good low-temperature flexibility and good elastic properties. The higher the ACN content, the better the resistance against polar media.

The gas permeability and flexibility at low temperature decrease in this context. NBR is only used sporadically in the food industry. The remaining applications are usually characterized by high mechanical forces, where a large energy input into the seal takes place. NBR resists this quite well, if no high demands in terms of temperature are placed on it and if a particularly cost-effective solution is sought.

General properties:
• Very good abrasion resistance
• The acrylonitrile content must be selected for each application in such a way that the material shows the optimal combination of chemical resistance and low-temperature flexibility
• Good mineral oil and fuel resistance and outstanding resistance to vegetable and animal oils, silicones, as well as to diluted acids and alkaline solutions at room temperature
• NBR tends to swell in aromatic and chlorinated hydrocarbons, as well as in polar solvents
• Temperature-resistant from –30 °C to +100 °C (–22 °F to +212 °F), special blends remain ?exible at low temperatures down to –55 °C (–67 °F)

Application profile:
NBR has very good properties in applications with mechanical stress and in oils, fats and waxes. Its temperature resistance in hot water is up to +100 °C (+212 °F). NBR cannot be used in concentrated acids (e.g. nitric acid, formic acid), concentrated oxidizing media (e.g. peracetic acid), and in aromatic and chlorinated hydrocarbons.

Durometer from 30 to 90, Temperatures from -70° to +300F° (-56° to +148C°) FDA O-Rings, 3A O-Rings, NSF O-Rings, Mil-Spec O-Rings and numerous specialized compounds for specific material certifications.

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