Rubber Materials

General guide to rubbers
Rubber is the most important class of materials for gasket sealing in the medium temperature range (-50 C to +120 C). This is because rubbers rapidly return to their original shape when any deforming stress or load is removed.

Many rubbers are available for various working conditions; however they all have one property in common - the effect of heat is cumulative and irreversible.

Maximum temperatures must not be exceeded and a good design will allow a safety margin dependent on design service life.

Many rubbers are available in foam (sponge) form for simple gasket sealing applications.

As a rubber gasket manufacturer we work in the following materials.

Types
Natural Rubber

Superb cut and abrasion resistance.
Very high tensile strength.
Good at low temperatures.
Poor resistance to mineral oils.
Poor resistance to ozone.
Expensive.
Temperatures -30 C to + 70 C.

SBR (Styrene Butadiene) Rubber - sometimes known as BUNA S (most "Commercial" rubber is SBR)
Inferior to natural rubber in strength and resistance to mechanical fatigue.
The everyday workhorse. Temperatures -30 C to +80 C.

Neoprene (Polychloroprene) Rubber
Good resistance to ozone and sunlight.
Will not support combustion - self extinguishes.
Fair resistance to oils. Temperatures -20 C to +110 C.

Nitrile (Butadiene Acrilonitrile) Rubber - sometimes known as BUNA N
Outstanding resistance to oils, petrols, solvents and lubricants.
Poor ozone resistance.
Food quality grades available (white).
Temperatures -20 C to + 110 C.

EP (Ethylene Propylene) and EPDM Rubber
Good chemical resistance.
Good mechanical properties and wear resistance.
Excellent weathering and ozone resistance.
Special types are approved by NWC (The National Water Council) for use with potable water.
Temperatures -40 C to +120 C.

Butyl (Isobutylene Isoprene) Rubber
Good acid and chemical resistance.
Low gas permeability.
Resistance to ozone.
High hysteresis loss (dead feel). Won't easily go back into shape.
Poor oil and petrol resistance.
Temperatures -40 C to +120 C.

Hypalon (Chlorosulphanated Polythelene) Rubber
Extreme resistance to ozone.
Good chemical and oil resistance.
Temperatures -40 C to +120 C

For further technical advice on rubber gaskets call us on +44 (0) 1209 314 700, or email mailbox@ramgaskets.co.uk