Abstract: An improved preform for blow molding a one-piece plastic container of the champagne base variety having an annular peripheral chime surrounding an inward sloping base portion for containing carbonated beverages. The preform defining interior and exterior walls which are ever decreasing in diameter from the neck to the base so that the preform may be easily removed from a mating core and injection mold cavity used therewith thereby avoiding the need for a split mold to form the preform. The preform including a thickened annulus adjacent the transition between side wall and base forming portions thereof and an exterior weight reducing annular concavity between the thickened annulus and the closed end of the preform.

Abstract: An improved one-piece plastic container of the champagne base variety having an annular peripheral chime surrounding an inward sloping base portion for containing carbonated beverages and associated methods for making same by blow molding. The preform defining interior and exterior walls which are ever decreasing in diameter from the neck to the base so that the preform may be easily removed from a mating core and injection mold cavity used therewith thereby avoiding the need for a split mold to form the preform.

Abstract: A one-piece plastic bottle of the champagne base variety having an annular peripheral chime surrounding an inward sloping base portion for containing carbonated beverages and associated methods for making the bottle by blow molding. To make the bottle resist to inversion of the base from internal pressure, an integral reinforcing ring is incorporated into the base and runs horizontally in the hoop direction. The reinforcing ring is placed in a location within the base that has a moment arm trying to invert the base and providing sufficient strength to withstand that moment arm and prevent inversion of the inward sloping portion.