High-barrier liner for beaded composite can

Abstract

A high-barrier liner for a composite container for products comprises a tubular body member comprising at least one paperboard body ply having an inner surface. The composite container further comprises a liner ply adhered to the inner surface of the tubular body member. The liner ply comprises a metallized film disposed between inner and outer sealant layers. The metallized film comprises a polymer film substrate and a vapor-deposited metal layer on one surface of the substrate. The metallized film is advantageously oriented such that the metal layer of the metallized film faces towards an interior of the composite container.

Description

BACKGROUND OF THE INVENTION [0001] Food and drink products and other perishable items are often packaged in tubular containers, which are sealed at both ends. These tubular containers typically include at least one structural body ply an impervious liner ply, and are formed by wrapping continuous strips of body and liner ply material around a mandrel of a desired shape to create a tubular structure. The plies may be spirally wound around the mandrel or passed through a series of forming elements so as to be wrapped in a convolute shape around the mandrel. At the downstream end of the mandrel, the tube is cut into discrete lengths and is then fitted with end closures to form the container. [0002] Current commercial containers often have membrane-type lids or end closures heat sealed to a curled or bead-shaped rim of the composite container wall to form a peelable seal. The rim is formed by turning outwardly the end of the container to position the inner layer of the liner material on...

AI Technical Summary

Benefits of technology

[0006] The present invention addresses the above needs and provides other advantages, by providing a container having a high barrier liner that comprises a metallized film oriented with the metal layer facing inwards towards the interior of the container. Surprisingly, it has been found that the directional orientation of the metal layer has an effect on barrier performance. In particular, the inward-facing orientation is superior to an outward-facing orientation in terms of barrier performance, and also is less susceptible to deterioration in high-temperature, high humidity conditions.

Problems solved by technology

Foil-based liners are relatively expensive.

Moreover, a liner comprising foil supported by a paper layer (e.g., kraft) has substantial thickness, and when the necessary fold seal is used to seal adjacent edges of the liner strip together (i.e., “anaconda” seal), this can create problems in forming a hermetic seal between a container end and a membrane lid.

However, liners based on metallized films have yet to attain acceptable barrier performance required for some high-barrier applications.

In addition, barrier properties of metallized films have been susceptible to deterioration under high temperature and high humidity conditions.

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