NBR Nitrile Rubber Compound

When fluid contact is the design constraint, the acrylonitrile (ACN) content of your nitrile rubber compound matters more than almost any other variable. Micune’s NBR compound range spans ACN levels from 18% to 45%, giving engineers the precise oil-resistance-to-flexibility balance each application demands — whether that’s a low-temperature-flexible fuel-return hose at 18–25% ACN or a…

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Specifications

Product Type：
Rubber Compound (raw compound) / Finished Molded Parts / Extruded Profiles

Base Polymer：
NBR (Nitrile Butadiene Rubber / Acrylonitrile-Butadiene Rubber / Buna-N)

Structure：
Solid (standard); sponge/foamed grades available on request

Color: 
Black (standard); gray, brown, custom colors available

Surface Finish：
Smooth / Matte / Per mold tooling

Standards & Compliance: 

Hardness:
40–85 Shore A (standard grades: 50, 60, 70, 80 ± 5 Shore A)

Tensile Strength: 
≥ 28 kN/m

Elongation at Break:
≥ 280% (medium ACN grade, 60 Shore A)

Tear Strength:
≥ 28 kN/m

Recommended Service Temperature:
-40°C to +120°C continuous; up to +150°C for short-term peak exposure

Hot Air Aging:
100°C × 70h: Hardness change ≤ ±8 Shore A; Tensile retention ≥ 75%

Low‑Temperature Brittleness: 
≤ -35°C (standard); ≤ -50°C for low-ACN cold-weather grades

Typical Applications:
Oil seals, fuel hoses, O-rings, hydraulic gaskets, automotive fluid-contact diaphragms

Description：

Not all nitrile rubber is the same elastomer. The acrylonitrile content — the percentage of acrylonitrile monomer in the NBR copolymer chain — is the single formulation dial that controls the trade-off between oil resistance and low-temperature flexibility. Push ACN higher, toward 40–45%, and the polar nitrile groups pack tightly enough to resist swelling in petroleum-based fluids, diesel, and hydraulic oils with impressive results. Pull it down to 18–25%, and the polymer chain stays mobile enough to remain flexible at -45°C, which matters enormously for fuel lines and seals on equipment operating in cold climates.
Micune maintains validated compound grades across four ACN bands. That’s not just a catalog claim — each grade has its own optimized filler loading, plasticizer system, and vulcanization recipe developed and tested in-house at the Zengcheng facility.

Typical Industry Applications：

Proven performance across demanding manufacturing environments.

Industry Typical Use Cases
Automotive & Motorcycle Engine oil seals, fuel tank filler neck hoses, transmission gaskets, brake system diaphragms, power steering hose jackets
Industrial Machinery Hydraulic cylinder seals, pneumatic valve seals, pump gaskets, oil-resistant conveyor belts, rotary shaft seals
Home Appliances Washing machine oil-drain hose, compressor valve plates, refrigerator compressor gaskets
Electronics & Electrical Equipment Oil-resistant cable jacket, grommet seals for junction boxes in oil-present environments
Agricultural & Construction Equipment Hydraulic hose inner liner, fuel-system O-rings, equipment sealing strips exposed to lubricants

Chemical Resistance Table：

Chemical / Medium Resistance Notes
Mineral engine oil (SAE 5W-30 to 20W-50) ✅ Excellent Core design strength of NBR; high-ACN grades preferred
Diesel fuel ✅ Excellent Use ≥ 33% ACN grade for extended immersion
Hydraulic oil (mineral-based) ✅ Excellent Standard medium-ACN grade suitable
Petroleum-based greases ✅ Excellent
Ethanol-blended fuel (E10–E85) ✓ Good High-ACN grade recommended; monitor swell with E85
IRM 901 / 902 / 903 reference oils ✅ Excellent Validated in-house per ASTM D471 methodology
Water (up to 70°C continuous) ✓ Good Not NBR’s primary strength; avoid steam above 100°C
Dilute acids (5–10% H₂SO₄, HCl) ⚠ Limited Short-term contact only; consult compound selection
Dilute alkalis (NaOH ≤ 10%) ⚠ Limited
Ozone / UV (outdoor weathering) ✗ Not recommended NBR backbone is unsaturated; use EPDM or CR for outdoor exposure
Aromatic hydrocarbons (toluene, xylene) ✗ Not recommended Significant swelling expected
Ketones (acetone, MEK) ✗ Not recommended Not compatible
Phosphate ester hydraulic fluids (Skydrol) ✗ Not recommended Use FKM or EPDM for phosphate ester exposure
Refrigerant oils (POE, PAG) ⚠ Limited Consult HNBR grades for compressor seal applications
Compressed air (dry) ✓ Good

In-House Quality Assurance & Testing:

At Micune Rubber, batch-to-batch consistency is guaranteed through our ISO-9001 certified Quality Management System. Every rubber compound and custom extrusion undergoes rigorous evaluation in our dedicated testing laboratory before shipment. We utilise industry-standard baseline testing, including Mooney Viscometers to measure compound viscosity and Torque Rheometers to verify exact vulcanisation characteristics. This ensures every material formulation strictly adheres to your required specifications and processing parameters.

Mooney Viscometer

Mooney Viscometer

abrasive testing machine

Abrasive Testing Machine

Burn-in Chamber

Burn-in Chamber

Torque Rheometer

Torque-Rheometer

RFQ：

For extruded NBR profiles, standard dimensional tolerances follow DIN 7715 P3 class (typically ±0.2–0.4 mm depending on profile complexity and wall thickness). Molded O-ring dimensions are quoted per AS568, ISO 3601, or customer-supplied drawings, with standard flash and parting-line tolerances per ISO 3601-3. Tighter tolerances are achievable for precision hydraulic seal applications — please provide target cross-section dimensions and the applicable standard when inquiring.

All NBR compounds supplied for export are formulated RoHS (EU) 2015/863 compliant and PAHs-compliant, with restricted substances confirmed Not Detected (ND) by SGS testing. REACH SVHC compliance documentation is maintained against the current candidate substance list. SGS test reports can be provided with initial qualification orders; for ongoing production, compliance documentation is issued per lot upon request.

Both ACN tier and hardness can be matched to a customer’s approved compound specification, provided physical property targets and fluid exposure conditions are shared. Cross-referencing against competitor compound data sheets or supplying a physical sample for reverse-engineering analysis is also feasible. Specifying your fluid medium, service temperature range, and target compression set value will allow the formulation team to recommend the closest in-library grade or initiate a development compound.

For compound-only samples (raw NBR compound slabs or pellets), sample preparation typically takes 7–10 business days from confirmation of formulation parameters. For molded finished parts requiring new tooling, mold fabrication runs 20–35 days depending on tooling complexity, with tooling cost quoted separately and credited against volume orders above agreed thresholds. Customers supplying their own tooling can typically receive first-article samples within 10–15 business days.

Minimum order quantity for custom NBR compound (raw compound form) is generally 200 kg per grade; standard commercial grades from the in-house library can be ordered from 100 kg. Compound is supplied in 25 kg wrapped slabs or film-wrapped rolls depending on viscosity grade. Export shipments are handled from Guangzhou with access to Guangzhou Port and Nansha Port, with standard lead times of 3–5 weeks for sea freight to most destinations after order confirmation.

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