Abrasion Resistance - The resistance of a material to loss of surface particles due to friction. When high abrasion resistance is required, Polyurethane (either thermoset or thermoplastic) is preferred.

Autoclave - A pressure vessel into which materials or articles can be placed and exposed to steam under pressure. It is commonly used to vulcanize carbon-based polymers, like EPDM, CR, Nitrile, and SBR.

Butt Joint - A joint made in a rubber part before or after vulcanization by placing the two pieces to be joined edge-to-edge. A butt joint is preferred over a mitered joint as the butt joint is typically stronger.

Compression Set – The residual deformation after removal of the force which has subjected the specimen to compression. Compression set is a key factor when designing a part that will be compressed for long periods of time.

Creep - The deformation, in either cured or uncured rubber under stress, which occurs with lapse of time after the immediate deformation.

Durometer – An instrument for measuring the indentation hardness of rubber; also, sometimes used as a synonym for hardness. For thermoset rubber and thermoplastic vulcanizate (TPV) materials, durometer is defined using the Shore A scale where the lower the value the softer the material.

Elongation – The maximum elongation prior to rupture.

Friction - Produced from the interference of two surfaces brought together. Parts in light friction will slide along each other easily but as friction is increased sliding becomes more difficult.

Low Temperature Flexibility - The ability of a rubber product to be flexed, bent, or bowed at specified low temperature without loss of serviceability. Silicone is typically the polymer of choice when low temperature flexibility must be maintained.

Microwave Curing - Heating a thick cross section uniformly is difficult using conventional ovens. Microwave technology however is not affected by dimensional considerations as the microwaves rapidly heat the insides and outsides of a profile simultaneously. A typical microwave extruder has a microwave unit at the end of the extruder to rapidly heat the extrusion and a HAV unit following to maintain temperature while vulcanizing. A significant benefit gained from microwave curing is that extremely long lengths can be achieved.

Modulus – The tensile strength recorded when the specimen is elongated 100%. For dynamic properties where the part will be stretched and compressed continually, a high modulus is preferred.

Permeability - To permit passage of gas through the molecular structure of a given material. Materials with low permeability, such as Butyl or FKM, are preferred in vacuum applications.

Tear Strength – The maximum load required to tear apart a specimen; the acting substantially parallel to the major axis of the test specimen. For applications where the part may experience some shearing action, a high tear material is preferred.

Tensile Strength – The maximum tensile stress applied during stretching a specimen to rupture. The higher the tensile strength, the stronger the material.

Vulcanization – An irreversible process during which a rubber compound through a change in its chemical structure (for example, cross-linking) becomes less plastic and more resistant to swelling by organic liquids and elastic properties are conferred, improved, or extended over a greater range of temperature.