General Rubber & Plastic Terms

"A" Face

The surface area of the part that is cosmetically important to public view.


The process of wearing down a materials surface due to friction.

Abrasion Resistance

The resistance to a materials surface wearing due to friction.


A cavity or sac that deforms the surface of a material.


A single small cavity surrounded partially or completely by walls.

Cellular Material

A generic term for materials containing many cells (either open, closed or both) dispersed throughout the mass.

Cellular Rubbers

A cellular material made of rubber. Cellular rubber products all contain cells or small hollow receptacles. The cells may either be open or interconnecting, or closed and not interconnecting.

Closed Cell

A cell totally enclosed by its walls and hence not interconnecting with other cells.


Inadvertent densification of a cellular material during its manufacture resulting from breakdown of its cellular structure.


An intimate mixture of a polymer with all the ingredients necessary for the finished article.

Compression Deflection

PSI to compress lab slab a specified percentage of overall height, normally 25%.

Compression Set

The residual deformation after removal of the force that has subjected the specimen to compression.


A surface effect on rubber articles characterized by many minute cracks.


The act of vulcanization. See vulcanization.


An instrument for measuring the hardness of vulcanized rubber or plastic. Shore 00 scale is for sponge, Shore A for dense/solid.

Durometer Hardness

An arbitrary numbering scale that indicates the resistance to indentor point of the durometer. High values indicate harder materials.

Expanded Rubber

Cellular Rubber having closed cells made from a solid rubber compound.

Open Cell

A cell not totally enclosed by its walls and hence interconnecting with other cells.

Ozone Cracking

The surface cracks, checks or crazing caused by exposure to an atmosphere containing ozone

Post Cure

Heat or radiation treatment to which a cured or partially cured rubber is subjected to enhance one or more properties.


A measure of the resilience, usually as the percentage of vertical return of a body that has fallen and bounced.


A material that is capable of recovering from large deformations quickly and forcibly, and can be, or already is, modified to a state in which it is essentially insoluble (but can swell) in boiling solvent, such as benzene, methyl ethyl, ketone and ethanol-tulene isotope.


Strain remaining after complete release of the load producing the deformation.

Shelf Aging

The time an unvulcanized rubber stock can be stored without losing any of its processing or curing properties.

Shore Hardness

An arbitrary numbering scale that indicates the resistance to indentor point of the durometer. High values indicate harder materials.


A relatively dense layer at the surface of a cellular material.

Sponge Rubber

Cellular rubber consisting predominantly of open cells made from a solid rubber compound.


A material upon the surface of which an adhesive is applied for any purpose such as bonding or coating.

Tear Strength

the maximum load required to tear apart a specified specimen, the load acting substantially parallel to the major axis of the test specimen.

Tensile Strength

the maximum tensile stress applied during stretching a specimen to rupture.


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.


the surface deterioration of a rubber article during outdoor exposure, such as checking, cracking, crazing or chalking.