Glossary - B's

Backrinding (r) a molding defect in which the rubber adjacent to the flash line shrinks below the surface of the molded product, with the flash line often being ragged and torn.

Bake-out (r) secondary post-curing operation designed to remove residual volatile materials.

Batch (r) the product of one mixing operation.

Beta particle an electron or positron emitted from a nucleus.

Bipolar transistor (sc) a transistor (consisting of an emitter, base and collector) whose action depends on the injection of minority carriers from the base by the collector.

Blank (r) a portion of a rubber compound of suitable volume to fill the cavity of a mold.

Bleeding (r) the exuding of a liquid compounding material from the surface of a vulcanized or unvulcanized rubber.

Blister (r) a cavity or sack that deforms the surface of a material.

Bloom (r) a liquid or solid material that has migrated to the surface of a rubber and generally changes the surface appearance.

Blowing agent (r) a compounding material used to produce gas by chemical or physical action, or both, in the manufacture of hollow or cellular articles.

Borophosphosilicate glass (BPSG) (sc) a compound of boron, phosphorus, silicon and oxygen.

Bound monomer (r) monomer that is combined or reacted with itself or other types of monomers in a polymerization reaction to form a polymer.

Breakaway friction (r) the force required to overcome friction to start a body in motion over a surface.

Brittle point (r) the temperature at which elastomers break when subjected to an impact.

Bulk modulus of elasticity (r) also known as compression modulus, the ratio of compressive force applied to a surface per unit surface area to the change in volume of the substance per unit volume.

Bumping, molding process (r) the application, release, and reapplication of pressure prior to the start of vulcanization to vent entrapped gases, thereby facilitating complete filling of the mold.

Butt joint (r) a connection made with two ends cut at right angles.

Next C's

Our specialty is solving sealing problems for original equipment manufacturers. We carry o-rings, seals, custom molded rubber parts, wipers, diaphrams, valves and u-cups in all types of materials including Aegis®, Viton®, Chemraz®, nitrile, buna-n, silicone, rubber, neoprene, polyurethane and teflon encapsulated elastomers.