Why is NBR OIL SEAL Better?

Nitrile, Buna-N or NBR rubber is a widely used elastomer, thanks in large part to its highly oil & fuel resistant properties and tensile strength. In this article, Martin’s Rubber Company explains more about the properties, applications, pros and cons of this versatile rubber material.   Nitrile rubber is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene that you may know better under trade names like Nipol, Krynac and Europrene N. Why might you consider specifying nitrile for your application? Let’s find out, with a closer inspection of this rubber material.

NNK Product Page

What is Buna-N?

Nitrile (also known as NBR rubber and Buna-N) is the seal industry’s most widely used and economical elastomer. This is partly because it displays excellent resistance to petroleum-based oils, fuels, water, alcohols, silicone greases, hydraulic fluids. However, it also has a good balance of desirable working properties like low compression set, high abrasion resistance and high tensile strength.

NBR rubber properties

Nitrile is a family of unsaturated copolymers of 2-propenenitrile and butadiene monomers (1,2-butadiene and 1,3-butadiene). Its physical and chemical properties vary depending on the polymer’s composition of nitrile. The more nitrile there is within the polymer, the higher its resistance to oils but the lower its flexibility. Nitrile rubber is more resistant than natural rubber to oils and acids, and has superior strength, but suffers from inferior flexibility.

Where is nitrile used?

Nitrile rubber is used in a wide variety of applications, such as O-rings, gaskets, oil seals, automotive transmission belts, hoses, V belts, synthetic leather, disposable non-latex gloves, printer’s form rollers and cable jacketing. NBR latex can also be used in the preparation of adhesives or as a pigment binder.

Pros and cons of Buna-N

Nitrile offers the following advantages:

• Excellent abrasion resistance.
• Good rebound.
• Good tear resistance.
• Good non-polar solvent resistance.
• Good water resistance.
• Good oil resistance.
• Cheaper than fluoroelastomers

Nitrile suffers from the following disadvantages:

• Poor ozone, sunlight, and weather resistance.
• Limited high temperature resistance.
• Poor flame resistance.

Nitrile rubber products from Martin’s Rubber

Speak to one of our advisers today to find out more about our nitrile rubber manufacturing capabilities. We can talk you through your options and give you honest and informed guidance to help you to specify the ideal product for your application. Speak to us today on 023 or [ protected]. For more information on why nitrile rubber is so popular for heat resistance, see our post: Why Buna N is so popular for use with hydrocarbons.

Oil seals play a critical role in preventing leakage and contamination in machinery, ensuring the efficiency and longevity of components. Among the most commonly used materials for oil seals are PTFE (Polytetrafluoroethylene) and NBR (Nitrile Butadiene Rubber). Each material has its own unique properties that make it suitable for different applications.

In this article, we will compare PTFE and NBR oil seals, highlighting their advantages, limitations, and best-use scenarios to help you make the right choice for your equipment.

1. Understanding PTFE Oil Seals

PTFE oil seals are made from Polytetrafluoroethylene, a synthetic fluoropolymer known for its exceptional chemical resistance, low friction, and high-temperature stability. These seals are commonly used in demanding applications where extreme temperatures, aggressive chemicals, and dry-running conditions are present.

Key Properties of PTFE Oil Seals:

✅ High-Temperature Resistance – Can withstand temperatures up to 260°C (500°F).
✅ Excellent Chemical Resistance – Resistant to oils, acids, solvents, and aggressive fluids.
✅ Low Friction and Self-Lubricating – Reduces wear and extends service life.
✅ Non-Stick Surface – Prevents the accumulation of dirt and contaminants.
✅ Ideal for Dry Running Applications – Suitable for applications with little to no lubrication.

Common Applications of PTFE Oil Seals: