Pressure equalization cap and bottle for use therewith

Abstract

The present invention provides a bottle cap for use in association with a bottle. The cap has a roof and sidewall, and is releasably attachable to the bottle. A flexible membrane is attached to the cap whereby an air tight seal between the flexible membrane and the bottle rim is achievable when the cap is attached to bottle. The flexible membrane is moveable responsive to change in pressure inside the bottle and the flexible membrane has an inside between the membrane and the cap. The cap has at least one flow means between the outside of the cap and the inside of the flexible membrane whereby air can move freely between the outside of the cap and the inside of the flexible membrane. The flexible membrane remains attached to the cap when the cap is removed from the bottle.

Description

FIELD OF THE INVENTION[0001]This invention relates to caps for plastic bottles and jars and in particular to caps that equalize pressure in the plastic bottle during cooling. The pressure equalizing cap of the present invention is particularly useful after a plastic bottle or jar has been hot filled or pressurized during filing by artificial means or by air pressure variations due to altitude changes.BACKGROUND OF THE INVENTION[0002]Plastic bottles are in many instances the preferred bottle for most applications. However, to date products and fluids that are hot filled will more typically be sold in glass bottles, composite cans, metal cans or foil and paper semi-rigid containers. Many bottlers would prefer to use plastic bottles since they are easy to use, easy to manufacture, recyclable, less expensive and generally easier to transport and do not break. But, when plastic bottles are hot filled the plastic bottle will often distort during cooling. In order to reduce this problem, m...

AI Technical Summary

Benefits of technology

[0006]The present invention provides a bottle cap for use in association with a bottle. The cap has a roof and sidewall, and is releasably attachable to the bottle. A flexible membrane is attached to the cap whereby an air tight seal between the flexible membrane and the bottle rim is achievable when the cap is attached to the bottle. The flexible membrane is moveable responsive to change in pressure inside the bottle and the flexible membrane has an inside between the membrane and the cap. The cap has at least one flow means between the outside of the cap and the inside of the flexible membrane whereby air can move freely between the outside of the cap and the inside of the flexible membrane.

Problems solved by technology

But, when plastic bottles are hot filled the plastic bottle will often distort during cooling.

Although these panels help the distortion problem, they pose problems for the bottler since it is more difficult to adhere a label to a bottle with panelling than a smooth surfaced bottle.

Generally, distortion of most types of plastic packaging occurs when the plastic container is filled at temperatures above 1850 F.

A further drawback of plastic packaging occurs when a plastic-based product package is filled with hot fluid and then capped immediately and left to cool.

A partial vacuum forms in the head-space in the container between the upper level of the food and the bottle cap with the consequent pressure differential between the interior of the bottle and the exterior resulting in distortion of the plastic container.

This effect is commonly referred to as panelling which is characterized by noticeable and unsightly distortion of the shape of the bottle.

Both these solutions add significant cost to the plastic container development costs.

Although these devices show ways of equalizing pressure in a plastic bottle, none of them are attaching the flexible membrane to the cap rather they attached the flexible membrane to the bottle.

Many consumers would find this unappealing.

Further, these prior art caps have a vent hole in the cap which poses tamper problems.

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