Glossary Terms U-V
Used in the Compression, Lamination and Transfer Molding Process

UNDERCURE:

State of vulcanization less than optimum. It may be evidenced by tackiness or inferior physical properties.

VENTING:

Removal of trapped air from the mold; accomplished either by the incoming injected rubber expelling the air via vent grooves cut into the mold, by the use of a mechanical vacuum pump to evacuate the closed mold chamber prior to the onset of injection, or by the use of receiver tanks to reach vacuum quickly.

VISCOSITY:

The resistance of a material to flow under stress.

VULCANIZATION:

An irreversible process in which the rubber's chemical structure is altered, and as a result, the properties of the rubber are improved.