Buna-N Gasket

Buna-N rubber is also known as Nitrile rubber. Nitrile elastomers are co-polymers of acrylonitrile and butadiene. The scientific name for Buna-N is acrylonitrile butadiene. The elastomer can be formulated with varying levels of acrylonitrile (ACN). The higher the content of ACN in the polymer formulation, the better the resistance to gasoline and aromatic oils. However, the lower ACN elastomers exhibit improved low temperature flexibility and tear resistance. Nitrile has a fairly impressive temperature range from -40° F to 250° F.

ASTM D1418 designation for this rubber is NBR. Buna-N rubber can be used as a general purpose sealing device such as O-Rings, seals, gaskets, diaphragms for oil field, automotive and aircraft industry. A popular use for nitrile is its use in the rubber glove industry. Rubber gloves are manufactured from nitrile where a non-latex glove is required.

Another elastomer belonging to Nitrile family is the hydrogenated acrylonitrile butadiene which is abbreviated HNBR per the ASTM D1418. This elastomer is similar but offers better heat, chemical and certain physical properties than regular NBR. NEDC works on applications including nitrile quite frequently and deals with the specifications associated, including MIL-G-1149, MIL-R-2765, MIL-R-6855 Class 1, and MIL-R-3065 SB (now superseded by the callout ASTM D2000 BG. In general the shelf life of Nitrile is 5-10 years.

Nitrile can be provided in many durometers from 30-90 Shore A. This rubber normally is provided in black because of the carbon black filler that is a reinforcing filler. NEDC can provide Buna-N materials with adhesive backing. NEDC can provide Nitrile rubber in sheet form, extruded cord stock, strips, die cut parts, water-jet cut parts, and molded parts. These parts are typically gaskets, or insulators. NEDC can provide the elastomer in a variety of durometers which is an indication of the elastomers resistance to compression.