Patent ID: 7931464

Claim:
An extrusion blow mold for forming a plastic bottle having a radial flange suitable for roll-form attachment to a metal can end without any different heating or cooling in the vicinity of the flange-forming features of the mold, the mold comprising: a pair of confronting mold halves, each mold half including a body forming portion, a bottom pinch-off portion located below the body forming portion, a top block portion including a blow chamber located above the body forming portion, and a spin-ring forming portion located between the body forming portion and the top block portion, the spin-ring forming portion including a thread ring insert having an inside upper edge including a radially outwardly extending surface defining a lower surface of a radial flange, the spin-ring forming portion additionally including a cutter ring insert positioned immediately above the thread ring insert, the cutter ring insert including a lower surface adjacent an inside edge defining an upper surface of the radial flange including a tapered inner edge extending upward and inward from the step, at least one of the thread ring insert and cutter ring insert including a relief surface connected to a vent channel to permit gas to escape from the area defining the radial flange.