US 4,792,048 AGranted

Gable-top container

AssigneeMinnesota Mining and Manufacturing Company

InventorGregory R. Wyberg

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Abstract

A gable-top thermoplastic coated container with controllably enhanced sealing and opening characteristics includes at least one stiffening fillet attached to the panels which form the spout. The fillet comprises a thin strip of stiff material coated with a layer of adhesive, and is bonded to at least one of the spout panels. The strip is resistant to the thermal container-sealing process, and extends along a major portion of the panel length to increase the force which may be transmitted to the tip of the spout where the fold back panels are adjoined, and prevent buckling of the spout panels. An adhesive web is delaminably bonded with a controlled release adhesive to the opposite surface of the strip, and is bonded to an opposed panel by the container sealing process. Delamination from the leakproof or hermetically sealed condition occurs at the interface between the strip and the delaminable adhesive, and is accomplished with a low opening force. The strip provides additional stiffness to the spout panels, enabling relatively high forces to be transferred to the spout tip where the opening forces act to open the container spout. The spout may be opened readily without significant tearing or delamination of the spout panels.

Claims22

Dependent claims

A sheet material blank for constructing a sealed gable-top container with a thermoplastic inner surface coating responsive to a container sealing process, said blank comprising:

(a) a container body having sides, a bottom and a top;
(b) an extensible pouring spout including a substantially triangular end panel connected to said container body top, first and second foldback panels, said first foldback panel connected to said container body top and to at least one lateral edge of said first triangular end panel, and said second foldback panel connected to said container body top and to the other lateral edge of said triangular end panel, a first roof wing panel adjoining said first foldback panel and connected thereto, a second roof wing panel adjoining said second foldback panel and connected thereto;
and
(c) at least one stiffening fillet overlying a portion of and bonded to the inner surface of at least one of said pouring spout panels for simultaneously stiffening said overlain panel to transfer applied opening forces therealong for opening at a controlled low opening force, said fillet comprising:
a strip of material resistant to the temperature and pressure of said container sealing process;
a first layer of adhesive attached to a first surface of said strip and to said inner surface of said at least one said panel for bonding said strip thereto;
and
an adhesive web including a controlled release adhesive delaminably attached to the opposite surface of said strip and adapted to bond by said container sealing process to another of said pouring spout panels wherein said opening forces transmitted along said strip delaminate said adhesive web from said opposite surface of said strip.

5 more elements

A hermetically sealed gable-top container for extended shelf life having a thermoplastic inner surface coating, said container comprising:

(a) a container body having sides, a bottom and a top;
(b) an extensible pouring spout including a substantially triangular end panel connected to said container body top and extending upwardly therefrom, first and second foldback panels, said first foldback panel connected to said container body top and to one lateral edge of said first triangular end panel, and said second foldback panel connected to said container body top and to the other lateral edge of said first triangular end panel, first roof wing panel adjoining said first foldback panel and connected thereto, a second roof wing panel adjoining said second foldback panel and connected thereto;
and
(c) at least one stiffening fillet disposed between and adhesively bonded to at least one of said pouring spout panels for stiffening said panel to transfer applied opening forces therealong and for controlling the force required to open said container, said fillet comprising:
a strip of material resistant to the temperature and pressure of said container sealing process;
a first layer of adhesive disposed between a first surface of said strip of material and said at least one panel and another of said panels, and adhesively joining said strip to said panels;
and
an adhesive web including a controlled release adhesive delaminably bonded to the opposite surface of said strip and bonded to an opposed panel, wherein said opening forces transmitted along said strip delaminate said adhesive web from said opposite surface of said strip.

5 more elements

Dependencies are inferred from the claim text.