Lightweight closure and container package

Abstract

A closure and container package for pressurized products, such as carbonated beverages, includes a closure comprising a closure cap having a top wall portion, and an annular skirt portion depending from the top wall portion. Features of the closure construction, and selection of the polymer from which the closure is formed, permits the closure to meet sealing, impact resistance, and other performance criteria, with desirably reduced use of polymeric material. Significant cost savings can thus be achieved.

Description

TECHNICAL FIELD[0001]The present invention relates generally to a closure and container package for carbonated beverages and the like, wherein the closure has been specifically configured for reduced use of polymeric material, while at the same time providing the required sealing performance for the carbonated contents of the package.BACKGROUND OF THE INVENTION[0002]Molded plastic closures formed from suitable polymeric materials have met with widespread acceptance in the marketplace. Closures of this nature, typically formed by compression molding or injection molding, have proven to be especially effective for use on containers having carbonated or otherwise pressurized contents. Experience has shown that providing effective sealing of a package having carbonated contents ordinarily requires a highly engineered closure to ensure effective sealing under a range of temperature and handling conditions. Additionally, closures of this nature typically include tamper-evident features, s...

AI Technical Summary

Benefits of technology

[0008]Notably, the development of the present closure has found that use of certain polymeric formulations, having a certain density, can be most cost-effective, while providing the desired level of closure performance. To this end, the present closure if preferably formed from high-density polyethylene polymer having a density of about 0.945 g / cm to about 0.97 g / cm. In one current embodiment, high-density polyethylene having a density of 0.955 g / cm has been successfully employed.

[0009]An important aspect of meeting the required performance characteristics for a closure used on carbonated beverages and the like is the dimensional consistency of the closure, notwithstanding variations in the polymer formulation. To this end, the polymer formulation preferably include a nucleator when a colorant is provided in the polymer, to thereby minimize dimensional variations of the closure. The polymer also preferably includes approximately 0.2 to 0.3% lubricant, by weight.

[0011]The sealing performance of the outer seal element is enhanced by provision of a plurality of circumferentially spaced, seal reinforcement elements on the inside surface of the skirt portion radially outwardly of the outer seal element, adjacent the top wall portion of the closure cap. The reinforcement elements are engageable by the outer seal element to limit outward deflection of the outer seal element, to thereby enhance sealing cooperation of the outer seal element with the associated container, and improve the impact resistance of the closure.

[0013]In the preferred form of the present closure, the internal thread formation of the closure cap is specifically configured to promote closure performance, while minimizing use of polymeric material. To this end, the internal thread formation is preferably configured to provide a variation in retention force which decreases in a direction away from the top wall portion of the closure cap. Generally speaking, this is achieved by providing a varying thread geometry for the internal thread formation, with the internal thread formation having a larger cross-section toward the top wall portion of the closure cap to provide more resistive force.

Problems solved by technology

As will be appreciated, a significant cost associated with closures of this nature is the polymeric material from which the closures are molded.

Images