Nozzles in the hot runner system are divided into open and closed nozzles.
Closed nozzles can be opened and closed with the help of a steel needle, therefore the name valve gate.
The needle pushes the gate flat and only a single round mark is visible after closure of the gate.
The filling and packing phase can be influenced directly by the control of the needle.

Valve Gate in Plastic Industry

Hot Runner: The movement of the needle opens and closes the valve gate.

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This glossary of plastic industry is provided by PLEXPERT Canada Inc.