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.
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.
