VAE
Vinyl Acetate-ethylene
Valve Gating
This type of gate is where a pin is held in the gate or channel by spring tension and as the plunger comes forward, it compresses the plastic in the runner. When this pressure build-up is sufficient to overcome the spring tension, the pin is then pushed back (pulled) and the fast decompression of the plastic fills the cavity at extremely high speed
Vent
A shallow channel or opening cut in the cavity to allow air or gases to escape as the material fills the cavity
Viscosity
The measurement of the resistance of a material to flow under stress
Volume Change
The measure of the swell or shrinkage of a material resulting from immersion in a particular media for a specified period of time at a specified temperature
Volume Swell
A term generally used to describe the increase in physical size of a specimen immersed in a particular chemical agent
Vulcanization
The thermally initiated, irreversible process whereby polymer chains are cross-linked to form the final physical and chemical state of a rubber
Warpage
Dimensional distortion in a molded object
Weathering
The detrimental effect upon an elastomer or plastic after outdoor exposure
Weld Lines
(knit lines) The marks visible on a finished part made by the meeting of two flow fonts during molding
Width
The cross-sectional diameter of an O-ring. one half the distance between the I.D. and O. D. of the ring
ZST
Zero strength time. A test for molecular weight
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