Glossary Terms G-H
Used in the Compression, Lamination and Transfer Molding Process

GLASS TRANSITION POINT:

Temperature at which a material loses its glass-like properties and becomes a semi-liquid.

GUM STOCK OR COMPOUND:

Rubber compound containing only those ingredients necessary for vulcanization and small amounts of other ingredients for processing, coloring, and for improving the resistance to aging.

HEAT HISTORY:

The accumulated amount of heat a rubber stock has been subjected to during proceeding operations, usually after incorporation of the vulcanizing agents. Incipient cure or scorch can, take place if heat history has been excessive.

HEAT TRANSFER:

Conduction of heat from the platen to the material to begin the cure process.

HYSTERESIS:

The heat generated by rapid deformation of a vulcanized rubber part. It is the difference between the energy of the deforming stress and the energy of the recovery cycle.