Vent insert design
Vol. 17 #3, Dec. 1990
Vent "bleeding" vs. vent flow can be from poor vent insert design. If all of the edges of the vent opening at the barrel are sharp with no downstream undercuts, the melt will be scraped off a little at a time eventually clogging the vent opening.
See also
Vent design
Vent flow
Vent plugging
Vent port fouling
Vents 2