Mold-Masters Hot Runner

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and cavity or runner system.

Stationary Platen: The large front plate of an injection molding press to

which the front plate of the mold is secured. This platen does not move during

normal operation.

Step: A transition component that provides a slight separation between the

bridge and the manifold and that allows the melt passage to connect the

bridge and manifold.

Thermal gate: A gate that is closed by temperature. Resin solidies in the

gate to block resin from owing out of the hot runner.

Thermoplastic: A polymer which melts or ows when heated. Thermoplastic

polymers are usually not highly cross-linked, and act much like molecular

solids: low melting and boiling points, high ductile strength.

Thermoset: A polymer that does not melt when heated. Thermoset polymers

“set” into a given shape when rst made and afterwards do not ow or melt,

but rather decompose upon heating. They are often highly cross-linked

polymers, with properties similar to those of network covalent solids, i.e., hard

and strong.

Valve Disk: Manifold component designed to be compressed by thermal

expansive forces to form part of the plastic sealing mechanism. Its high

tolerance bore allows the valve pin to shift through it without plastic leakage

and part of it enters the melt stream and helps guide the plastic ow without

stagnation.

Valve Gating: An injection molding method that uses a mechanical shut o󰀨 to

open and close the gate orice.

Vent: A shallow channel or opening cut in the cavity to allow air or gases to

escape as the melt lls the cavity.

21-5GLOSSARY OF TERMS

Hot Runner User Manual

Mold-Masters Hot Runner - Page 315