When you’re introduced to the world of manufacturing and producing seals, gaskets, and other custom-cut parts, you’re stepping into a wonderful world of thousands of different materials that each bring remarkable and unique qualities to the project they’re needed for. From the simple qualities like hardness and water resistance, to the ability to withstand a 900°C (1650°F) oven, non-metallic materials can be surprisingly versatile materials. However, because there are so many materials, finding the right one can be difficult and daunting. Nitrile butadiene rubber is one such material; here’s what you need to know!
What is Nitrile Butadiene Rubber?
Nitrile butadiene rubber, also called NBR, is a petroleum-based synthetic rubber that is oil-resistant. NBR is a commonly-used elastomer—particularly in the seal industry. It was first developed in Germany in 1931 at BASF and Bayer, entering commercial production in 1935. NBR is a copolymer comprised of two monomers: acrylonitrile (ACN) and butadiene. The properties of the final compound are determined by its ACN content, which is broken down into three categories:
- High nitrile: >45% ACN content
- Medium nitrile: 30-45% ACN
- Low nitrile: <30% ACN
So, why would you need more or less ACN content? It all comes down to the properties you need. A high nitrile rubber will have better resistance to hydrocarbon oils, while low nitrile will have better flexibility—especially in a low-temperature setting. With that in mind, it wouldn’t surprise you to hear medium nitrile is the most widely used since it balances the properties of the other two.
Nitrile is mostly used where high oil resistance is required. Therefore, it’s most commonly found in automotive gaskets, seals, and other items that frequently come into contact with hot oils. Other applications include disposable non-latex gloves, hoses, O-rings, V belts, cable jacketing, and even synthetic leather. Nitrile butadiene is also made in a hydrogenated version—called HNBR—which boasts high resistance to thermal and oxidative deterioration while also remaining flexible at low temperatures.
Nitrile Butadiene has many applications, including latex-free medical gloves.
What Are the Benefits and Drawbacks of NBR?
In addition to its resistance to oils and low-temperature application, NBR also has excellent abrasion resistance; good rebound properties; and tear, water, and non-polar solvent resistance. It’s also cheaper than fluoroelastomers. On the other hand, though, NBR has poor ozone, sunlight, and weather resistance. It also has limited resistance to high temperatures and flame.
So, is nitrile butadiene rubber the material you need? Maybe you need something else. No matter the application or the need, Breiner Innovative has the materials and the expertise you need to get reliable parts on time, every time. Have a project? Contact us today.