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Product Info
Rubber Compounds
1. Nitrile : Nitrile Butadien Rubber (NBR):Properties
NBR is used primarily for its good oil resistance in seal and gasket applications. Its good compression set and low temperature flexibility are
its important features. It has high resilience to mineral oils, vegetable oils and many acids. It has poor age resistance and its heat
resistance is also limited to around 80°C under continuous operating conditions.
Uses for NBR:
a. Seals and gaskets
b. Linings
c. Washers
d. General oil resistant mouldings
Limitations:
a. Generally attacked by ozone, ketones, esters, aldehydes, chlorinated and nitro hydrocarbons.
b. See chemical resistance chart on home page
2. EPDM: Ethylene Propylene Diene Modified Rubber :Properties
EPDM has excellent age and UV resistance. It also has good heat resistance up to 150ºC (120°C continuous) and is chemically resistant to
most acids. EPDM has high conductivity when carbon black is mixed into the compound. EPDM is not recommended as an electrical
insulator.
Limitations:
a. No oil resistance. Attacked by mineral oils, solvents and aromatic hydrocarbons
b. Flammable
c. High gas permeability
d. See chemical resistance chart on home page
3. Butyl Rubber: (IIR) Isoprene Isobutylene Rubber: Properties
Butyl Rubber has very low gas permeability (retains gases). It also has low resilience (no bounce) and excellent aging characteristics. Its
chemical resistance is excellent.
Limitations:
a. See chemical resistance chart on home page
4. Viton : Fluorinated Rubber: Properties
This is a speciality synthetic rubber. It is primarily used in high temperature, oil resistant applications. They also have excellent resistance
to weathering, ozone and oxygen. Viton Fluoroelastomers retain their basic properties at high temperatures. They have good tensile
strength, resilience and low compression set.
Limitations:
a. Very expensive
b. Limited hardness’s available.
c. Only moulding applications at Carlin Medical Extrusions.
d. See chemical resistance chart on home page
5. Silicone Rubber: Vinylmethyl :VMQ: Properties
Silicone rubbers have excellent heat and cold resistance. The temperature ranges are from - 100ºC to + 250ºC. They are also UV
resistant and have excellent electrical insulating properties. Silicone rubbers are also used extensively in the medical industry.
Limitations:
a. They are not oil resistant.
b. Unreinforced silicones have lower tensile strengths than most other members of the elstomer family
c. Silicones are attacked by many solvents, concentrated acids and diluted hydroxide.
d. See chemical resistance chart on home page
Properties of Silicone
Rubber Type | Hardness Shore A | Tear Strength
N/mm² | Tear propagation Strength N/mm | Compression set
% | Solid Rubber
Multipurpose grades | 40-70 | 8 | 17 | 35 | | High mechanical strength | 40-70 40-70 | 10
10 | 18
35* | 30 30 | | Low compression set | 40-70 | 7 | 15 | 10 | | No-post-cure grades | 40-70 | 7 | 15 | 25 | | Grades for cable and wire insulation | 60-70 | 8 | 25 | | | Oil-resistant grades | 70 | 5 | 25 | 35 |
*Although two rubbers may have the same tear strength, they may differ in tear-propagation strength
6. Fluoro Silicone Rubber: Fluorovinylmethyl :FVMQ: Properties
They have high/ low temperature and oil resistant applications. They are also resistant to aromatic solvents and have a low compression
set. The temperature ranges are from - 60ºC to + 180ºC. This rubber competes with Viton and is easily extruded and moulded.
Limitations:
a. Very expensive
b. See chemical resistance chart on home page
7. Polyuretane: Properties
It has good resistance to ozone and oxygen and excellent abrasion resistance and tear strength. It also has good elongation, high tensile
strength and a low coefficient of friction.
Limitations:
a. It’s not recommended for use around acids and alkalis and has limited high temperature applications
b. See chemical resistance chart on home page
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