Extrusion-Coated Lidding Foil For Push-Through Blister Packaging

Abstract

An extrusion-coated lidding foil for blister packaging particularly suitable for push-through pharmaceutical and food blister packaging. The lidding foil includes a foil layer on which one or more tie layer and one or more sealant layer, one or both of which include an embrittling agent mixed therein, are extrusion coated resulting in a lidding foil having push-through ability. The push-through ability of the lidding foil is characterized by a Mullen burst strength of about 10 psi to about 30 psi and an MD tear strength of about 30 to about 100 grams-force.

Description

FIELD OF THE INVENTION[0001]The present invention relates to packaging having a lidding foil. The invention is particularly useful for push-through blister packaging and is directed to an extrusion-coated lidding foil useful for such packaging.BACKGROUND OF THE INVENTION[0002]“Blister packaging” is a common term used for packaging having a bottom part, typically referred to as the “blister film”, with a plurality of recesses formed therein (e.g., through vacuum forming or pressure forming) wherein a respective product piece (e.g., a consumable tablet or pill) is positioned and held therein. A cover, typically referred to as a “lidding foil” is placed over and sealed to the blister film about the perimeter of each recess.[0003]There are basically three different types of blister packaging which relate to how the consumer is meant to retrieve the consumable from its respective recess within the sealed package: push-through type, peel-push type and lock type. In the “push-through” type...

AI Technical Summary

Problems solved by technology

If extruded too thinly, breaks within the curtain could cause voids, which could leads to breaches in the package seal.

A thicker layer of sealant (as one gets with an extrusion coating process as compared to the gravure coating process) may therefore be used for peel-away lidding foils to ensure complete sealing, but is inadequate for push-through blister packaging application.

The polymers presently used for the blister film of the package either do not create a complete barrier to moisture and air, and / or they may contain plasticizers that are subject to blooming and can contaminate the consumable.

Insufficient barrier properties allow moisture and air seepage into the package over time which shortens package shelf life.

Also, contamination of the consumable by additive blooming may be harmful to human health.

Unfortunately, for push-through type lidding foils, the heat seal lacquers presently used for push-through blister lidding foils exhibit difficulty adhering efficiently directly to PCTFE (Aclar®), COC, and other similar materials having the above beneficial properties.

While the above patents and applications describe various lidding foils, blister films and sealants for blister packaging, neither the industry nor the prior patent publications above have provided an extrusion-coated lidding foil for push-through blister packaging.

Furthermore, the prior art fails to disclose or teach an extrusion-coated lidding foil for push-through blister packaging which may be sealed directly to PCTFE (Aclar®), COC, or similarly a beneficial material having enhanced barrier and inert properties.

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