Compression molded preform for forming invertible base hot-fill container, and systems and methods thereof

摘要

A compression molded preform for forming an invertible base hot-fill container, and systems and methods thereof. The preform includes a body with a first open end, a second closed end or end cap of hemispherical shape, and a sidewall extending between the first end and the second end. At least a portion of the second end is thinner than any portion of the sidewall. Further, the second end is gateless and has an inner surface that is substantially smooth along its entire area. The compression molded preform is blow molded to form a plastic container with an invertible or movable base. The invertible or movable base is responsive to, or can be moved based on, internal forces or pressure associated with processing the container with a filled product.

主权项

1. A compression molded plastic preform for forming a blow molded plastic container having an invertible base portion, the preform having a hollow body defining an inner volume, the preform body comprising:
a first, open end defining an opening into the inner volume, the first end having threads; a second, closed end opposite the first end in a length-wise direction of the preform body; and an intermediate portion between the first end and the second end, the intermediate portion having a sidewall extending in the length-wise direction of the preform body along a central longitudinal axis of the preform body and a transition portion adjacent the second closed end, the intermediate portion tapering from a relatively thin portion adjacent the first open end to a relatively thick portion and tapering from the relatively thick portion through the transition portion to the second closed end, the transition portion including an outer surface with a first curved portion having a convex cross-section in side view and a second curved portion having a concave cross-section in side view, wherein the second end of the preform body is gateless and without a weld line, wherein the second end is hemispherical, an entirety of an outer surface of the second hemispherical end being smooth, and an inner surface of the second hemispherical end at least at a portion of the second end not at the central longitudinal axis being smooth and without any sharp transitions, and wherein the second end has a portion that is thinner than any other portion of the preform.