Patent ID: 9056409
Filing Date: 2015-06-16
Classification: B29C

Abstract:
1. A process for molding a closure-support ring that is adapted to mate with a brim of a container and with a closure to form a lid configured to close a mouth opening into an interior region formed in the container when the closure-support ring is mated with the brim and the closure is mated with the closure-support ring, the process comprising the steps of providing a ring-shaped mold cavity formed in a mold to surround a central axis of the mold and sized and shaped to form the closure-support ring when filled with plastics materials, first injecting a first plastics material into the ring-shaped mold cavity at a first location to divide the first plastics material into outer first and second streams and to cause the outer first stream of the first plastics material to flow in a clockwise direction along a first path in the ring-shaped mold cavity toward a third location that is provided in the ring-shaped mold cavity and arranged to cooperate with the first location to establish a diameter of the ring-shaped mold cavity and to cause the outer second stream of the first plastics material to flow separately from the outer first stream in a counterclockwise direction along a second path in the ring-shaped mold cavity toward the third location, second injecting a second plastics material into the ring-shaped mold cavity at the first location after the first injecting step and while the outer first and second streams of the first plastics materials are flowing along separate first and second paths in the ring-shaped mold cavity from the first location toward the third location to divide the second plastics material into inner first and second streams and to cause the inner first stream of the second plastics material to trail the outer first stream of the first plastics material and to flow along the first path in the clockwise direction in a channel formed in the outer first stream of the first plastics material as the outer first stream of the first plastics material flows from the first location to the third location and to cause the inner second stream of the second plastics material to flow separately from the inner first stream of the second plastics material to trail the outer second stream of the first plastics material and to flow along the second path in a channel formed in the outer second stream of the first plastics material as the outer second stream of the first plastics material flows from the first location to the third location, merging a leading skin melt front of the outer first stream of the first plastics material moving along the first path and a leading skin melt front of the outer second stream of the first plastics material moving along the second path in the mold cavity to establish a merged skin knit line in the ring-shaped mold cavity, and overlapping a leading core melt front of the inner first stream of the second plastics material moving along the first path and a leading core melt front of the inner second stream of the second plastics material moving along the second path to lie in close proximity to one another after the merging step to displace any of the first plastics material extant between the leading core melt fronts of the inner first and second streams of the second plastics material and to align the leading core melt fronts of the inner first and second streams of the second plastics material in radially overlapping relation so that one of the leading core melt fronts lies between the central axis of the mold and the other of the leading core melt fronts.