Knurled pull-tabs

Abstract

A closure package includes a closure cap and a liner having a pull-tab. The liner is configured for use with a container having a finish or lip portion having a sealing surface at an uppermost portion thereof. The closure cap has a top wall portion and a depending skirt portion depending from the top wall portion. The top wall portion and sealing liner is adapted to coact with the container sealing surface to form a seal therebetween. The liner of the subject invention is for use with a closure package and is disposed in cap, positioned intermediate the top wall portion and the container sealing surface when the cap is positioned on the container. The liner is circular and has a central portion and a tab portion integral with the central portion, extending outwardly from a periphery thereof. The tab is folded on or above a tangent to the periphery of the liner, over the central portion into a folded position, and defines a hinge region at the juncture of the tab and outside the tangential line to the liner circumference. The tab is knurled to provide an improved, secure grip.

Description

FIELD OF THE INVENTION[0001]The invention relates to an inner seal for a container and more particularly to a pull-tab for the inner seal to permit a proper seal while allowing for easy removal of the inner seal to the container.BACKGROUND OF THE INVENTION[0002]A heat sealable inner seal is often used in sealing a container for products such as anti-freeze, peanut butter, mayonnaise, liquid detergent, etc. Such an inner seal prevents leakage and is also popular for providing an indication of whether there has been tampering with the contents of a container.[0003]Presently, a heat sealable inner seal generally includes a multi layer composite structure with an upper layer of metallic foil which is attached to a lower layer of adhesive material which bonds the heat seal material. The inner seal also can include an upper backing layer. Generally, the inner seals are inserted into caps and shipped to a packager of containers. The packager places the caps onto filled containers, with the...

AI Technical Summary

Benefits of technology

"The closure package described in this patent includes a liner and a cap that work together to create a seal on a container. The liner is positioned inside the cap and is circular with a tab that folds over the top. The tab has a scoring system to lie flat in the closure and can be easily gripped to pull the liner off. The technical effect of this design is that it provides a reliable and easy-to-use closure for containers, ensuring a tight seal and efficient use of the liner."

Problems solved by technology

If the foil is heated to too low a temperature, the bonding between the heat sealable layer and container may be weak or may not occur, thus preventing the inner seal from performing its sealing function.

If the metallic foil is heated to too high a temperature, the heat sealable layer may burn which may also prevent proper sealing.

There are, however, a number of drawbacks to the hammered tab arrangement.

First, when a relatively resilient liner material is used, the tab tends to return to its unstressed state, and unfolds, regardless of the force used to hammer the tab into the folded position.

This can be particularly troublesome if the closure forming process is stopped and liners have not yet been positioned inside of their respective closure caps.

It has been observed that the tabs tend to unfold and often become caught or jammed on the cap threads or inner lip of the container during insertion of the liner into the cap.

When this occurs, the liners do not properly seat within the cap and the cap must be rejected.

Further, the folded tab may cover too much or too little of the container lip and thus result in an imperfect seal

Images