The unheated melt channel from machine nozzle / hot runner up to the cavity is called cold runner.
In the injection molding cycle the cold runner is cooling down and freezes.
The gate geometry is very flexible, like umbrella gate, cashew gate, ring gate.
The cold runner is ejected together with the part.
The separation from the part is done automatically or manually.
The collected cold runners will be recycled or disposed as waste.