The following is a list and general description of some of the more common materials used in manufacturing industrial seals and packings.
Nitrile (NBR), also known as Buna-N, is a copolymer of butadiene and acrylonitrile (ACN). Butadiene provides elasticity and low temperature flexibility and also contains the unsaturated double bond that is the site for cross-linking. Acrylonitrile imparts hardness, tensile strength, and abrasion resistance as well as improves on fuel, oil, and gas impermeability and heat resistance, dependent on percentage of ACN content. Increasing ACN content reduces low-temperature flexibility and increases hardness. General-purpose nitrile compounds with a 34% ACN content have a recommended temperature range of -40°F to 225°F.
| NBR-770 Nitrile 70 Shore A | |
|---|---|
| Hardness (Shore A) - ASTM D-2240 | 70 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 2200 |
| Ultimate Elongation, % - ASTM D-412 | 300 |
| Modulus @ 100%, PSI - ASTM D-412 | 500 |
| Compression Set, Method B, % - ASTM D-395 | 9 |
| Specific Gravity | 1.30 |
| NBR-780 Nitrile 80 Shore A | |
| Hardness (Shore A) - ASTM D-2240 | 80 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 2280 |
| Ultimate Elongation, % - ASTM D-412 | 260 |
| Modulus @ 100%, PSI - ASTM D-412 | 820 |
| Compression Set, Method B, % - ASTM D-395 | 10 |
| Specific Gravity | 1.25 |
| NBR-790 Nitrile 90 Shore A | |
| Hardness (Shore A) - ASTM D-2240 | 90 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 2300 |
| Ultimate Elongation, % - ASTM D-412 | 200 |
| Modulus @ 100%, PSI - ASTM D-412 | 1600 |
| Compression Set, Method B, % - ASTM D-395 | 12 |
| Specific Gravity | 1.30 |
Fabric reinforced nitrile rubber is made up of nitrile rubber with a cotton duck insert added incrementally throughout the thickness of the material. This process makes the rubber more durable and have a higher degree of strength under hot or cold loads. This material can work with a range of pressures, from a vacuum to medium pressure. Recommended application temperature range is -40°F to 250°F.
| F-202 Fabric Reinforced Nitrile 90 Shore A | |
|---|---|
| Base Fabric - Plain Weave Cotton | |
| Weight | 10.8 oz/yd2 |
| Count | 32 x 28 |
| Coating - NBR (Nitrile) | |
| Hardness (Shore A) - ASTM D-2240 | 80 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 1500 |
| Ultimate Elongation, % - ASTM D-412 | 350 |
| Coated Fabric | |
| Weight | 18.8 oz/yd2 ± 10% |
| Hardness (Shore A) - ASTM D-2240 | 90 ± 5 |
Fluorocarbon (VITON®/FKM) compounds or fluoroelastomers are thermoset elastomers that contain fluorine. Fluorocarbons are excellent for general purpose O-rings because of their exceptional resistance to chemicals, oil, and temperature extremes. Fluorocarbons typically have good compression set resistance, low gas permeability, and resistance to ozone and sunlight. Recommended application temperature range is -15°F to 400°F.
| FLU-170 Fluorocarbon 70 Shore A | |
|---|---|
| Hardness (Shore A) - ASTM D-2240 | 70 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 1950 |
| Ultimate Elongation, % - ASTM D-412 | 195 |
| Modulus @ 100%, PSI - ASTM D-412 | 900 |
| Compression Set, Method B, % - ASTM D-395 | 16 |
| Specific Gravity | 1.81 |
| Color | Black |
| FLU-180 Fluorocarbon 80 Shore A | |
| Hardness (Shore A) - ASTM D-2240 | 80 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 1750 |
| Ultimate Elongation, % - ASTM D-412 | 193 |
| Modulus @ 100%, PSI - ASTM D-412 | 900 |
| Compression Set, Method B, % - ASTM D-395 | 16.2 |
| Specific Gravity | 1.80 |
| Color | Black |
| FLU-190 Fluorocarbon 90 Shore A | |
| Hardness (Shore A) - ASTM D-2240 | 90 ± 5 |
| Tensile Strength, PSI - ASTM D-412 | 1850 |
| Ultimate Elongation, % - ASTM D-412 | 130 |
| Modulus @ 100%, PSI - ASTM D-412 | 1600 |
| Compression Set, Method B, % - ASTM D-395 | 16.2 |
| Specific Gravity | 1.80 |
| Color | Black |
Additional materials used for manufacturing seals and packings include the following:
| Material | |
|---|---|
| HYDROGENATED NITRILE (HNBR) | |
| ETHYLENE PROPYLENE (EPDM/EPM) | |
| CHLOROPRENE (NEOPRENE) | |
| SILICONE | |
| EPICHLOROHYDRIN (HYDRIN) | |
| BUTYL RUBBER | |
| POLYURETHANE | |
| HYTREL® | |
| NYLON | |
| MINLON® | |
| HD POLYETHYLENE | |
| LEATHER | |