© 2006 Wabash MPI
Glossary of Terms A-BGlossary Terms used in the Compression and Transfer Molding ProcessA-B • C-D • E-F • G-H • I-J • K-L • M-N • O-P • Q-R • S-T • U-V • W-XACCELERATOR:Added to rubber to speed up vulcanization and improve the properties of the final product. AGE:The length of time required between molding and evaluation of molded part properties; will generally range from 24 hours on. AMBIENT TEMPERATURE:The temperature of the atmosphere or medium surrounding the object under consideration. ANTIOXIDANT:Protects rubber against chemical changes and harmful effects of heat, sunlight, and air. BACKRIND:A defect at the parting line where the material has shrunk inside the part. BALANCED RUNNER SYSTEM:Runner design to ensure common heat history and fill time for all mold cavities. BATCH:Normally referred to as one drop from a rubber internal mixer; batch-to-batch variations in properties may cause problems in molded part quality unless operating parameters are adjusted to compensate. BLOOM:A surface discoloration of a molded part after a time in which a substance has migrated to the surface; most often caused by an overabundance of an additive or if sulfur, to a state of under cure. BULK DENSITY:The density of loose material (powder, cubes, etc.) expressed as a ratio of weight to volume. BULK MOLDING COMPOUND:Raw molding material consisting of unsaturated polyesters with reinforcement systems, including glass fibers or minerals. BUMP:("Breathe") "bump" is more commonly used in rubber or composite molding, Clamp pressure; is relieved for a short duration, and often multiple times during a cycle to vent trapped gases in the material. Compression Molding Presses | Vacuum Molding Presses | Transfer Molding Presses Wabash MPI |