Nitrile Rubber (NBR)

Nitrile Rubber Roll

Acrylonitrile Butadiene Rubber (NBR) was the first oil resistant synthetic rubber developed in 1941. It was historically referred to as “Buna N” and is often simply referred to as Nitrile rubber. Nitrile is the standard rubber used in situations where oil-resistance is needed.

Nitrile is a copolymer of butadiene and acrylonitrile. The butadiene component provides the elasticity of the rubber. The properties of Nitrile mainly depend on the amount of acrylonitrile in the rubber compound. High amounts of acrylonitrile result in a rubber with better oil resistance whereas compounds with low acrylonitrile content have better low temperature flexibility and resilience.

The grade descriptions of Nitrile depend on the percentage of acrylonitrile present in the rubber. Rubbers with higher acrylonitrile content will have better oil and fuel resistance, tensile strength, hardness, abrasion, gas impermeability and heat resistance. However, high acrylonitrile content can also lead to low temperature flexibility, resilience, and plasticiser compatibility.

Key Properties of Nitrile:

  • Good bonding strength
  • Excellent resistance to hydrocarbon oils, fuels, and greases
  • Very good heat resistance in the absence of air
  • Good hot air resistance (long term 90 °C, 40 days at 120 °C, 3 days at 150 °C)
  • Very low gas permeability
  • Low permanent set (needed for good sealing)
  • Moderate low temperature flexibility (depending on the amount of acrylonitrile)
  • Moderate tear and tensile properties
  • Available in food grades, WRAS accredited grades and pharmaceutical grades

Drawbacks:

  • Requires protective agents for good oxygen and UV resistance.
  • Inherently poor ozone resistance (difficult to protect against).
  • Plasticiser selection is critical to avoid loss or extraction from heat and fluids. Causes shrinkage and embrittlement in seals and hose linings.

Operating Temperature Range: -25 to +100 °C

  • Low acrylonitrile materials can operate down to - 50°C
  • Peroxide cured materials can be used at temperatures up to +150°C

Chemical Compatibility:

  • Excellent resistance to oils and fuels
  • Good resistance to aliphatic hydrocarbons (propane, butane, petroleum oil, mineral oil and grease, diesel fuel, fuel oils)
  • Good resistance to vegetable and mineral oils and greases
  • Good resistance to many dilute acids, alkalis, salt solutions at low temperatures
  • Good water resistance
  • Not well suited for ozone or weather resistance
  • Not compatible with fuel of high aromatic content, toluene, benzene, chlorinated hydrocarbons, hydrogen sulphide.
  • Not compatible with polar solvents (ketone, acetone, acetic acid, esters)
  • Incompatible with Strong acids
  • Incompatible with Glycol based fluids

Typical Applications:

  • Gaskets in which the oil regularly encounters fuel or oil
  • Fuel tank seals
  • Oil seals
  • Gearboxes
  • Oil hoses
  • Petrol hoses
  • All forms of seals for mineral oil and fuel sealing
  • Gaskets and seals – food and water contact
  • Aerosol gaskets – pharmaceutical and cosmetics
  • Hose and tank linings

Nitrile Sheet

Black nitrile (10% content) / SBR rubber 70 shore. It is used where a cheaper quality material will suit in simple applications such as packing pieces, dust seals, protection pads etc where the material is not coming under any duress and slight resistance is required. Ideal for use in products when oil resistance is required such as fuel hoses, automotive seals, gaskets, rollers and in printing and textiles, nitrile rubber is an oil-resistant synthetic rubber. This product is fully CE, PAH, ROHS, REACH compliant with excellent mechanical characteristics, black nitrile rubber sheeting is suitable for use with fuels, oils, greases and water.

Specification:

  • Polymer content: 10%
  • Density: 1.45sg
  • Hardness: 70 shore a
  • Tensile strength: 40 kg/cm2
  • Elongation at break: - 200%
  • Min temperature: -30 °C
  • Max temperature: +90 °C

Available Finishes: 'SS' has a smooth finish on both sides, 'CC' has a cloth-print finish on both sides and 'CS' has a smooth finish on one side and a cloth-print finish on the other.

We stock a majority of these strip materials at all times, so the likely lead time will be between 1 and 2 days. However, should we not hold the specific product required, we'll be able to provide within 3-5 days. Get in touch to discuss any specific requests.

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