NATURAL RUBBER [NR] [IR] [SBR]
This is available in many grades, from pure latex to filled mixed qualities for specific
uses (i.e. Bridge Bearing rubber, Snow Blade rubber). Although highly acid and
abrasive resistant Natural rubber is not generally used for weathering and should
not be used with oils. The temperature range of -40°C to +80°C does not normally
allow this material to be used in non-ambient environments. Often this group
includes Isoprene (IR) and Styrene Butadiene (SBR). Again natural rubber is
available in solid or sponge sheet form.
REINFORCED RUBBER (INSERTION)
Most of the above rubbers can be supplied with reinforcement either in the sheet
or on top or bottom (as in the case of belting material). This basically increases the strength of the material and is
normally required when sealing against higher pressure, or in the case of diaphragm material, where pressure
accompanied by continuous flexing occurs. Simple coated fabrics are also available for use as covers, aprons, skirts
etc.
NEOPRENE [CR]
Chloroprene, generally known under the DuPont trade name of Neoprene, this
material
is probably the most commonly used synthetic rubber. With a temperature
range of -20ºC to + 100ºC and good resistance to oils, chemicals and ageing,
the material is also
flame retardant. Available in solid or sponge form.
NITRILE [NBR]
Acrylonitrile-Butadiene Rubber has excellent resistance to water, oil and fuel with superior compression set and
abrasive resistance. The temperature range is -20ºC to 110ºC and the material is used generally for sealing in
automotive type applications. Not particularly resistant to ozone or weathering this material is also available in solid
and sponge form.
BUTYL [IIR]
With a fine molecular structure, Butyl is aptly suited to Gas and Water sealing with
its very low permeability. Having a temperature range of -50ºC to + 120ºC, Buty
also has excellent ageing, ozone and chemical resistance. Although good for ester
based hydraulic oils and electrical Applications, Butyl is not suitable for use with
petroleum Oils and fluids.
ETHYLENE PROPYLENE [EPDM]
Ethylene Propylene rubber has very good resistance to weathering and general
chemicals however it should not be used with petroleum products. Also available
to meet Water Research Council requirements it is widely used in the potable water
markets. With a temperature range of -40ºC to + 120ºC EPDM is also suitable for
steam and glycol ether fluids.
POLYURETHANE [AU]
This material is available in sheet form for many applications. Being very hard wearing it is particularly suited to
applications where high durability is required, such as scraper blades and press tools. The material is resistant to oils,
many solvents, greases and ozone however it should not be used with acids or alkalis or at elevated temperatures.
GASKETS CUT TO ORDER
SILICONE [Q Grp]
Although not suitable for use with mineral oils this material is normally used where
high temperatures are involved, having a temperature range of -60ºC to +250ºC.
Silicone also has very good electrical properties and is suitable for outside use,
however it has poor tensile strength, tear, abrasion and steam resistance. This
material is available in solid or sponge where required.
HYPALON [CSM]
Chlorosulphonated Polyethylene Rubber (or Hypalon, the DuPont trade name, as it is better known) has excellent
weathering, abrasion, acid and flame resistance. It is often used as an intermediate grade between lower grade
synthetic rubbers and Viton. With a temperature range of -20ºC to + 120ºC this material is becoming increasingly used
in automotive 'under-bonnet' applications, and is now regularly used as a binder with cork for this purpose.