Base for pressurized bottles

Abstract

A plastic bottle with a base centered on a vertical axis, a continuous standing ring to support the bottle, a side wall formed unitarily with the base extending from the base upward to an upper side wall end, and a neck connected to the side wall upper end, the neck including a finish adapted to receive a cap to close an opening into the bottle interior. The bottle base standing ring is defined in vertical cross-section by a continuous curve bounded on a radial inside by an interior region that can include a plurality of concave domed wedge-shaped sections interspaced with buttress sections having substantially planar inclined outer portions. The bottle base standing ring has a diameter less than 80% of the maximum side wall width and is bounded on a radial outside by a conic section portion centered on the vertical axis having an apex angle of less than 1600 to improve the perpendicularity of the bottle.

Description

BACKGROUNDThe present disclosure is directed to plastic bottles, and particularly to a supporting champagne style base that is unitary with the remainder of the bottle, which improves the perpendicularity of the bottle.Plastic bottles that include a base having a continuous uninterrupted standing ring for supporting the bottle on any underlying surface are sometimes referred to having a champagne style base. The perpendicularity or vertical alignment of such bottles can depend on the evenness of material distribution in the area of the standing ring, particularly when the bottles are subjected to even small internal pressures of 15 psi or less. While small variations from a true vertical alignment can be tolerated, any significant variation may cause problems in subsequent labeling and boxing of such bottles. While a large diameter standing ring is generally thought to provide enhanced stability as a result of the larger foot print, the large diameter standing ring is more flexible ...

AI Technical Summary

Benefits of technology

A plastic bottle has a base centered on a vertical axis. The base has a continuous standing ring to support the bottle on any underlying support surface. A side wall is formed unitarily with the base and extends from the base upward to an upper end of the side wall. A neck is unitarily connected to the upper end of the side wall that includes a finish adapted to receive a cap to close an opening into the bottle interior. The bottle has a height defined by the distance between the opening and the standing ring, and a maximum width across the bottle. To enhance the vertical alignment or perpendicularity of the bottle, the base standing ring can be defined in vertical cross-section by a continuous curve. The base standing ring can have a diameter less than 80% of the maximum side wall width. The continuous curve of the base standing ring can be bounded on a radial inside by an interior region that includes a plurality of concave domed wedge-shaped sections interspaced with buttress sections having substantially planar inclined outer portions. The continuous curve of the base standing ring can be bounded on a radial outside by a conic section portion centered on the vertical axis.

The vertical alignment or perpendicularity of the bottle can be enhanced by limiting the apex angle of the conic section portion to less than 160°. The vertical alignment or perpendicularity of the bottle can be further enhanced by maintaining the width of the conic section portion to at least 0.035 inches (0.889 cm).

The vertical alignment or perpendicularity of the bottle can also be enhanced by limiting the standing ring diameter to be more than 70% of the maximum bottle side wall width. The vertical alignment or perpendicularity of the bottle can be further enhanced by limiting the average standing ring thickness to between 1.0 and 1.3 times the thickness of the side wall. The vertical alignment or perpendicularity of the bottle can be further enhanced by limiting variation in the standing ring thickness to less than ±20%. Another feature of the base that can improve the vertical alignment or perpendicularity of the bottle is confining the vertical cross-sectional radius defining the standing ring to between 0.100 inches (0.254 cm) and 0.300 inches (0.762 cm).

Another feature of the base that can improve the vertical alignment or perpendicularity of the bottle is limiting the curvature of the concave dome portion to a radius of at least 1.0 times the standing ring diameter. The vertical alignment or perpendicularity of the bottle can be further enhanced by buttress sections that have inclined outer portions that can be inclined at an angle of between 8° and 16° with respect to a plane defined by the base standing ring. The vertical alignment or perpendicularity of the bottle can be further enhanced by providing the angle of tangency at the point of intersection of the concave dome portion and the standing ring vertical cross-section to be at least 45°.

Problems solved by technology

While small variations from a true vertical alignment can be tolerated, any significant variation may cause problems in subsequent labeling and boxing of such bottles.

As a result, even small variations in material distribution in large diameter standing rings can lead to unacceptable variations in the vertical alignment or perpendicularity of the bottle.

A significant disadvantage of using preforms having significant non-uniform wall thicknesses to place additional material in the chime in direct alignment with the standing ring is the additional polymer itself, which increases the cost of the bottle.

Images