Refillable polyester container and preform for forming the same
AssigneeContinental PET Technologies, Inc.
InventorsSuppayan M. Krishnakumar, Wayne N. Collette, Thomas E. Nahill
Life of this patent
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Abstract
This relates to a returnable/refillable container in the form of a blow molded polyester biaxially oriented bottle wherein the container includes a domed base construction wherein the wall thickness gradually and smoothly increases to a maximum at the center of the dome. This also relates to a specially configurated preform which is blow molded to form the container and a specially configurated blow mold cavity for receiving a preform having a lower axial projection in the fore of an elongated gate without crushing.
Claims16
A preform for use in blow molding a container suitable for refilling, the preform being an injection molded polyester member having:
- a closed bottom end and an open top end;
- a neck finish at the open top end;
- a body-forming portion which on blow molding will form a body of the container;
- a shoulder-forming portion disposed between the neck finish and the body-forming portion and which on blow molding will form a shoulder of the container;
- and
- a base-forming portion which on blow molding will form a base of the container, the base-forming portion having a generally hemispherical outer surface at the closed bottom end and a thickened portion between the bottom end and the body forming portion, the thickened portion having an increased wall thickness as compared to the wall thickness of the body-forming portion;
- characterized in that the base-forming portion has a generally hemispherical inner surface at the bottom end and the thickened portiom has an upper cylindrical portion of the increased wall thickness and a lower tapered portion which gradually reduces in wall thickness towards the bottom end.
A preform for use in blow molding a container suitable for refilling, said preform being an injection molded member formed of a polyester, said preform having an elongated body for forming a container body and being closed at one end and open at the opposite end, said preform open end having a neck finish with said preform between said neck finish and said elongated body having a portion tapering in wall thickness for forming a container shoulder portion, said closed one end being defined by a bottom having a generally hemispherical outer surface, and between said closed one end and said preform body there being a cylindrical container base forming thickened portion of an increased wall thickness as compared to the wall thickness of said preform body, said preform being improved by said bottom also having a generally hemispherical inner surface with the wall thickness of said bottom gradually reducing in thickness towards said one end.
Dependencies are inferred from the claim text.