Abrasion Resistance - A rubber compound's capability to withstand mechanically caused deterioration.

Accelerated Life Test - A test made to replicate in a short period of time the breakdown resulting from normal working conditions.

Accelerator - A substance that increases the speed of vulcanization when used in small quantities in conjunction with vulcanizing agents.

Activator - A compound used to increase the effectiveness of an accelerator, small amounts at a time.

Adhesion - Tendency of rubber to cling or bond to any surface it contacts.

Aftercure - The continuance of vulcanization, even after the energy source has been taken away.

Air Checks - Depressions and marks on the surface of rubber, caused by air trapped during the molding process.

Autoclave - Uses steam under pressure to vulcanize rubber products.

Backrind - A defect in the molding process, where the rubber near the parting line sinks below the surface and the parting line ends up ragged and torn.

Batch - The result of a mixing operation.

Blank - Rubber compound that fills a mold.

Bloom - A discoloration of rubber, caused by a liquid or solid migrating towards the surface.

Breakout Friction - The necessary force to start the sliding between a rubber seal and its mating surface.

Chalking - The development of a powdery residue on a rubber surface as a result of surface breakdown.

Checking - Small cracks on the surface of rubber, usually from environmental damage.

Compression Set - The permanent deformation of rubber after removing the compression.

Conducting Rubber - Rubber that is able to conduct electricity.

Crosslink - A chemical bond between polymer chains.

Cure Date - The date of completion of the molding process for a rubber product.

Deflashing - Any of a variety of processes for waste edge removal from molded rubber parts.

Dispersion - The application of force used to evenly disperse various compounds through rubber.

Durometer - An instrument that measures the hardness of rubber.

Dusting - Applying powder to rubber to prevent adhesion to something else.

Dynamic Seal - A seal necessary for the prevention of leaks beyond parts that are in relative motion.

Elasticity - A characteristic of rubber, describing its tendency to return to its initial shape after warping.

Elongation - Extension of rubber when exposed to stress.

Extruder - A machine that forces rubber through a hole that shapes it into the finished product.

Fatigue Breakdown - The wearing out of elastomers after repeated deformations.

Flexural Strength - The flexing capability of a material with no permanent deformation or breakage.

Flow - Capability of uncured rubber to move in the mold and runner system in the molding procedure.

High Consistency Rubber (HCR) - Rubber processed on a rubber mill that has a much greater viscosity than liquid silicone rubber.

Hysteresis - The process of mechanical energy changing to heat in rubber under strain.

Insert - A material that rubber is chemically or physically bonded to during the molding process.

Logy - Slow recovery rate of rubber after stress.

Mastication - The softening of raw rubber by mechanical and atmospheric forces.

Monomers - A chemical compound that is able to endure polymerization.

Non-Fill - A defect that occurs when the rubber does not completely fill out the mold.

Parting Line - A line on the surface of rubber resulting from where the two halves of the mold met.

Peptizer - A material that is used to quicken the softening of rubber compounds under heat or mechanical action.

Pigment - An insoluble compound that gives rubber its color.

Plasticity - The degree to which rubber will retain deformation.

Polymerization - Chemical reaction in which one or more simple materials are transformed into complex materials that have different properties from the originals.

Reinforcing Agent - A substance that is added to rubber to increase its resistance to the harms of the vulcanization process.

Scorch - The result when rubber vulcanizes too quickly.

Spew - Extra material that leaks from the mold as it closes.

Splice - The term for the uniting of two parts of vulcanized rubber to make a whole.

Vulcanization - A thermo-setting reaction that involves the use of pressure and heat, and results in highly increased elasticity and strength of materials like rubber.