An injection mold consists in general of two halves: injection side and ejection side.
The touching faces between these two halves are called parting line.
Through this, the air is transported from the cavity to the outside.
When the mold is opened, part and cold runner are separated from the mold at this line and ejected.
The parting line emerges in general as a surrounding seam on the part.
This glossary of plastic industry is provided by PLEXPERT Canada Inc.