NBR (Nitrile Butadiene Rubber) is a widely used synthetic rubber known for its excellent resistance to oils, fuels, and other chemicals. It is commonly used in applications requiring durability, flexibility, and resistance to harsh conditions.
NBR, a synthetic rubber, is known for its resistance to oils and fuels, making it ideal for industrial and automotive applications.
Keep reading to discover what makes NBR an essential material for industries ranging from automotive to healthcare.
What Is NBR?
NBR, or Nitrile Butadiene Rubber, is a copolymer of acrylonitrile and butadiene. The higher the acrylonitrile content, the more resistant NBR becomes to oils and fuels, but its flexibility decreases.
NBR is a synthetic rubber formed by combining acrylonitrile and butadiene, offering resistance to oils and fuels.
NBR Composition
- Acrylonitrile Content: NBR’s acrylonitrile content typically ranges from 18% to 50%, which influences its oil and fuel resistance.
- Butadiene Content: The butadiene content provides flexibility, making the material more versatile in different temperature ranges.
Applications of NBR
NBR (Nitrile Butadiene Rubber) is a synthetic rubber known for its resistance to oil, fuel, and other chemicals. It's a copolymer of acrylonitrile and butadiene, with trade names including Perbunan, Nipol, Krynac, and Europrene. NBR's properties vary with its nitrile content; higher nitrile content increases oil resistance but reduces flexibility.
Common applications of NBR:
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Automotive and Aeronautical Industry:
- Fuel and oil handling hoses
- Seals
- Grommets
- Self-sealing fuel tanks
- Suitable for temperatures from -40 to 108 °C (-40 to 226 °F)
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Sealing Materials:
- Food-grade seals
- Water-cut seals
- Oil seals
- O-rings
- Resists oil, fuel, grease, water, air, and flame-retardant liquids
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Gloves:
- Disposable non-latex gloves for:
- Food service
- Medical
- Nuclear industries
- Superior strength and resistance to oils and acids compared to natural rubber
- Disposable non-latex gloves for:
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Other Applications:
- Automotive transmission belts
- V belts
- Synthetic leather
- Printer's form rollers
- Cable jacketing
- Adhesives
- Sealants
- Sponges
- Expanded foams
- Floor mats
- Hydraulic hoses
- Conveyor belting
- Oil field packers
- Rubberized fabrics
- Roll covers
- Sheets
- Shoe soles
- Rubber matting under carpet at golf driving ranges
- Suitable for static and dynamic hydraulic seals
| Application Area | Examples | Key Properties Leveraged |
|---|---|---|
| Automotive/Aeronautical | Fuel/Oil Hoses, Seals, Grommets, Self-Sealing Fuel Tanks, Transmission Belts, V-Belts | Oil & Fuel Resistance, Wide Temperature Range, Durability |
| Sealing | O-Rings, Oil Seals, Food-Grade Seals, Water-Cut Seals | Oil & Fuel Resistance, Water Resistance, Chemical Resistance, Air Resistance |
| Protective Gear | Disposable Nitrile Gloves (Medical, Food Service, Nuclear) | Oil Resistance, Acid Resistance, Superior Strength compared to Latex |
| Industrial/Other | Synthetic Leather, Printer Rollers, Cable Jacketing, Adhesives, Sealants, Sponges, Floor Mats, Hydraulic Hoses | Chemical Resistance, Durability, Versatility in Various Forms (Foams, Sheets, Fabrics) |
Is NBR Synthetic Rubber?
Yes, NBR is a synthetic rubber, meaning it is man-made through the polymerization of chemical compounds rather than being derived from natural latex.
NBR is a synthetic rubber, produced by polymerizing acrylonitrile and butadiene, making it ideal for demanding industrial applications.
Why Synthetic?
NBR’s synthetic nature allows manufacturers to control its properties, such as oil resistance and flexibility, making it ideal for specific industrial requirements.
Advantages of Synthetic Rubber
Synthetic rubbers like NBR offer consistency, can be engineered for specific applications, and are often more durable than natural rubber in extreme conditions.
What Is the Hardness of NBR Rubber?
NBR rubber can vary in hardness, typically ranging from 40 to 90 Shore A, depending on the specific grade and its intended application. Hardness is an essential factor in determining the performance of rubber components like seals and gaskets.
NBR rubber can range from 40 to 90 Shore A hardness, making it adaptable for a variety of applications, from seals to heavy-duty components.
Hardness and Performance
- Lower Hardness (40-60 Shore A): Provides better flexibility, making it suitable for sealing applications.
- Higher Hardness (70-90 Shore A): Offers more durability and resistance to wear, ideal for industrial components subjected to heavy loads.
Measuring Hardness
The hardness of NBR rubber is typically measured using the Shore A scale, which evaluates how the material responds to indentation.
What Are the Properties of NBR 70?
NBR 70 refers to a specific grade of Nitrile Butadiene Rubber1 that has a Shore A hardness2 of 70. This grade offers a good balance of flexibility and resistance to oils, making it suitable for a wide range of applications.
NBR 70 offers a balance of flexibility and oil resistance3, making it suitable for a variety of sealing and gasket applications in industries like automotive and manufacturing.
Key Features of NBR 70
- Oil and Fuel Resistance: NBR 70 excels in resisting oils, fuels, and many chemicals.
- Durability: It provides a good balance of durability and flexibility, making it versatile for various sealing applications.
- Temperature Resistance: NBR 70 performs well in temperatures ranging from -40°C to 100°C.
Applications
NBR 70 is widely used for o-rings, seals, and gaskets in automotive, oil, and gas industries, where resistance to petroleum-based fluids is crucial.
What Is the Difference Between NBR 90 and NBR 70?
The primary difference between NBR 90 and NBR 70 is the Shore A hardness, which affects their flexibility, durability, and resistance to wear.
NBR 90 is harder and more durable than NBR 70, offering superior wear resistance, but at the cost of reduced flexibility.
NBR 70 vs NBR 90 Comparison Table
| Property | NBR 70 | NBR 90 |
|---|---|---|
| Hardness (Shore A) | 70 | 90 |
| Flexibility | Moderate | Low |
| Durability | Good | Excellent |
| Oil Resistance | High | Very High |
| Temperature Range | -40°C to 100°C | -40°C to 120°C |
Choosing Between NBR 70 and NBR 90
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NBR 70: Ideal for applications requiring a balance of flexibility and resistance to petroleum-based fluids. It's a general-purpose material suitable for most environments and is commonly used in standard O-rings. NBR 70 provides good mechanical properties and high wear resistance.
Examples:
- Carburetor and fuel pump diaphragms
- Aircraft hoses
- Seals and gaskets
- Oil-lined tubing
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NBR 90: Best for applications involving higher pressures and temperatures. NBR 90 provides good mechanical properties and high wear resistance.
Conclusion
NBR is an essential material in various industries due to its excellent properties, such as resistance to oils and fuels. Whether choosing NBR 70 for flexibility or NBR 90 for durability, NBR continues to play a key role in the manufacturing of seals, gaskets, and o-rings.
Footnotes:
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Explore this link to understand the unique properties and diverse applications of Nitrile Butadiene Rubber, enhancing your knowledge in material science. ↩
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Learn about Shore A hardness and its significance in determining the performance of rubber materials, which is essential for making informed choices in engineering. ↩
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This resource will provide insights into how oil resistance plays a crucial role in selecting materials for various industrial applications, ensuring durability and performance. ↩
