A Detailed Guide To NBR Oil Seals

Nitrile rubber (NBR) oil seals are widely used in various industries due to their unique properties and characteristics. The following is a detailed introduction from different aspects:

1. Material properties and history

NBR, also known as Buna-N, is a synthetic rubber composed of acrylonitrile (ACN) and butadiene. The ACN content is usually between 15% and 50%, which determines the resistance and flexibility of the material. NBR was patented in 1934 by German chemists Erich Konrad and Eduard Tschunkur, and its production in the United States during World War II made it popular in American industry.

2. Characteristics

• Oil resistance:  NBR is particularly resistant to petroleum, mineral and vegetable oils, as well as some acidic solutions and water. The increase in acrylonitrile content gives the compound higher strength, greater resistance to hydrocarbon oils, and lower gas permeability.

• Temperature resistance:  NBR can operate at temperatures from -20°F to 170°F. Some high-performance NBRs can reach 150°C.

• Flexibility:  NBR remains flexible at low temperatures, which is critical for applications outdoors or in refrigerated environments.

• Tensile Strength and Durability:  NBR has high tensile strength and resistance to wear and tear, making it strong and durable in applications involving dynamic movement or mechanical stress.

• Chemical Resistance:  NBR has good resistance to a wide range of chemicals, such as acids, bases, and solvents.

3. Applications

NBR oil seals are used in a wide range of industries and applications:

• Automotive:  NBR is used in engine seals, drive belts, and fuel systems due to its oil resistance. It is also used in door and window seals for sealing and shock absorption.

• Industrial Equipment:  NBR seals are used in hydraulic and pneumatic systems to ensure reliable operation.

• Oil and Gas Industry:  NBR is a reliable source for seals and gaskets in equipment that comes in contact with crude oil, natural gas, and drilling fluids.

• Pharmaceuticals and Food:  NBR seals meet food-grade and pharmaceutical-grade standards and are used to seal food processing and pharmaceutical equipment.

4. Manufacturing Process

NBR requires ingredients to be added for formulation and further processing to be made into useful items. Processing includes mixing, preforming into the desired shape, application to the substrate, extrusion, and vulcanization to make finished rubber products.

5. Market Analysis

The NBR market is growing due to its versatility and performance in a variety of applications. Seals and O-rings dominate the product segment in terms of revenue share in 2023, with important uses in automotive parts and other pressure-sensitive applications.

6. Limitations

NBR compounds are susceptible to attack by small amounts of ozone, which reduces compatibility for long-term outdoor exposure. In addition, commercial quality nitriles may contain less than 10% ACN, which can affect their performance.

In summary, NBR oil seals are valued for their oil resistance, flexibility, and durability, making them an integral part of a variety of industrial applications. Their performance characteristics and wide range of applications highlight their importance in modern engineering and manufacturing. 

The nitrile rubber (NBR) oil seals produced by Jinwoseal are made of high-quality raw materials to ensure long-term use benefits. Each production process has a strict quality inspection procedure to ensure that each product can seal effectively. Come to Jinwoseal to find the sealing solution that suits you.

For more common oil seals, please refer to this article：Detailed Guide on Oil Seals