US3543993A

US3543993A - Arrangement in square packages

Info

Publication number: US3543993A
Application number: US799801A
Authority: US
Inventors: Hans Anders Rausing
Original assignee: Tetra Pak AB
Current assignee: Tetra Pak AB
Priority date: 1968-02-20
Filing date: 1969-02-17
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01
Also published as: JPS4944278B1; CH505734A; GB1253144A; DE1908304A1; FR2002241A1; NL6902620A; SE317914B

Description

O United States Patent [72] Inventor Hans Anders Rausing [56] References Cited Lulld, sWden UNITED STATES PATENTS P NO. 799,801 3,178,089 4/1965 Tobias et al. 229/1710) [221 Feb-17,1969 3,295,739 1/1967 w116x 229/17(G) [451 patimted R: 3,319,868 5/1967 Huang 61811.. 229/17(G) [731 Ass'gnee 3,334,799 8/1967 Crawford v229mm) Lund, Sweden a s gdl h Company Primary Examiner-David M. Bockenek [32] Priority Feb. 20, 1968 ArtorneyPierce, Scheffler & Parker [33] Sweden [31] No. 2176/68 [54] EK T E R PACKAGES ABSTRACT: In a square gabletop package of cardboard or 3 Claims paper having an internal coating of thermoplastic material and [52] (1.8. CI 229/ 17, forming an upper closure means having wall portions sealed to 229/37 each other and adapted to be opened by breaking such seal, [51] Int. Cl. 865d 5/08, there is provided adjacent said seal a cut separating areas of 865d 5/74 the thermoplastic layer, the thermoplastic layer above said out [50] Field of Search 229/37, being less strongly adhered to said paper or cardboard than 17(G) the thermoplastic layer below said cut.

Patented Dec. 1, 1970 Fig.1

INVENTDR Hans Anders Rausm Ail fegs ARRANGEMENT. IN SQUARE PACKAGES The present invention relates to an arrangement in packages of the so called gable top type which are prepared from a basic layer of cardboard or paper having a coating of thermoplastic material which will lie inside the package when the latter is erected from the plastic-coated blank and consisting of four sidewalls united along their lateral margins, a bot tom and an upper closure means which can be opened and which consists of four end wall portions united with the sidewalls and with each other at the lateral margins, said end wall portions being inclined in pairs towards each other and having marginal portions heat sealed to each other which form extensions of the end wall portions, the marginal portions of two opposite end wall portions lying folded like bellows between the marginal portions of the two remaining end wall portions and at least one of the two inwardly folded marginal portions being moveable outward together with the pertaining end wall portions from its position between the two outer marginal portions to a new position outside these where the marginal portion after being moved outward, as well as its pertaining end wall portion. form a pouring spout and an emptying passage.

When one of the marginal portions are pulled out in order to open the package and form the corresponding end wall portion into a pouring spout, the heat sealing must be broken in order that the inwardly folded marginal portion may be separated from the outer marginal portions. There are considerable difficulties in controlling this breaking of the heat sealing, and in many cases it will happen that the surface of fracture extends into the paper material and that parts thereof will be torn loose and fall down into the contents of the package. The uncontrolled breaking also entails that-an uncomfortably large force must be used in order to open the package, since the tearing of the material in the side portion will spread therefrom over a larger surface than necessary.

In order to avoid these drawbacks and provide a package of the kind described which is easy to open there is provided according to the invention a package of this kind wherein the end wall portion which can be moved outward in order to form a pouring spout has a cut penetrating through the internal thermoplastic layer and extending over the greater portion of the width of the end wall portion and located closely to or adjacent the marginal portion which can be moved outward, and wherein the thermoplastic-layer in those areas of the end wall portion and the marginal portion which are located above the said cut'has an inferioradhesion tothe basic paper'or cardboard layer than those parts of the thermoplastic layer which are located below said cut. a

The weaker adhesion between the basic layer and the thermoplastic layer is preferably provided by a coating of a sub stance which will prevent the sealing of the two layers or make such sealing difficult.

When a package of this kind is opened the'plastic layer on the inwardly folded marginal portion will come loose therefrom within the sealing zone and will remain on the outer marginal portions, the loosening of the plastic layer from the inwardly folded marginal portion being prevented from spreading outside the sealing zone due to the cut penetrating the plastic layer therebelow.

Further objects and advantages of the invention will be apparent from the following description of a preferred embodiment shown in the accompanying drawings, in which:

FIG. 1 shows a gable top package having an arrangement according to the invention and being in a closed state;

FIG. 2 shows the package in an open state; and

FIG. 3 shows part of a plane blank for making a package arranged according to the invention.

The package shown in the drawings has four sidewalls 1 and a bottom (not shown). F urthermore. the package has four end wall portions 2 which are united on one hand with the sidewalls l and on the other with each other. At the upper free margin the end wall portions 2 are provided with marginal portions 3, 4, which are moved together in such a way that opposite end wall portions 2 are inclined in pairs towards each other and that the marginal portions 3 of two'oppos'ite end wall portions lie folded like bellows between the marginal portions 4 of the two remaining end 'wall portions. Thus, the end wall portions 2 which are provided with the inwardly folded marginal portions 3 will, as shown in FIG. 3, be divided into three essentially triangularportious, the intermediate one 5 of which extendsbetween the end wall portions 2 provided with the outer marginal portions 4, while the two side portions rest against the inside of each one of these.

The package consists of a basic outer layer of cardboard and an inner coated on layerof thermoplastic material, and the scaling of the package with the marginal and end wall portions in the position shown and described is brought about by means of heat, which will fuse the thermoplastic layers with the sealing zone.

When the package is to be opened the heat sealing is torn open over one half of the sealing zone, whereupon the inwardly folded marginal portion located in said zone is pulled out to the position shown in FIG. 2, where the marginal and the end wall portions will. form a pouring spout.

FIG. 3 shows part of a blank for a package of the indicated kind. The FIG. shows essentially only that part of the blank which is to form the inside surface of the marginal and end wall portion of the package, which can be opened. The blank is provided with crease lines along which the blank is to be folded so as to form the finished package. In order to facilitate the opening of the package it has according to the invention a portion 7 shown in hatching in FIG. 3 within which the adhesion between the thermoplastic material and the cardboard material is weaker than in-the rest of the package. The portion 7 is correlated to marginal portions 3 of the end wall which functions to form the pouring spout. Moreover, the said portion 7 is essentially separated from the rest of the ther- Q parallel with the edge of the blank across substantially the entire width of the end wall having the inwardly

foldable portions

3, 3. When the package is opened the surface of fracture will consequently form in an essentially predetermined manner since the thermoplastic layer within the portion 7 having weaker adhesion to the cardboard material will remain adhered to the thermoplastic layer of those marginal portions 4 with which it is fused at the heat sealing operation and the surface of fracture in the sealing portion will not extend farther thanto the cut 8. p

The weakened adhesion is produced by treating the cardboard material at the portion 7 with a substance facilitating, loosening, e;g. silicon oil or wax. When silicon oil is used the adhesion of the thermoplastic layer becomes essentially nonexistent whereas when wax is used a weakened adhesion is obtained. The preferred substance is wax or wax mixtures, which may contain silicon preparation. The substance which prevents or weakens the adhesion of the plastic layer may be applied to the cardboard layer by means of a normal printing process, e.g. at the same time as the cardboard layer is provided with a decor.

At the manufacture of the package blanks the web of material is displaced in a direction transversely of the longitudinal axis of the finished package, which entails that the cuts between the plastic layer and the zones of reduced adhesion between plastic and paper will extend in the direction of movement of the web and become relatively simple to achieve.

lclaim:

l. A package of the gable top type comprising four sidewalls united by vertical fold lines along their lateral edges, a bottom, and a top of the gable type formingan openable closure means for the package, said gable top comprising fourend walls united respectively withthe four sidewalls along horizontal fold lines and also united with each other along vertical fold lines which form continuations of the vertical fold lines uniting said sidewalls, said end walls being inclined in pairs towards 3 each other and having marginal portions heat sealed to each other which form extensions of said end walls the marginal portions of two opposite end walls being folded inwardly between and sealed to the marginal portions of the other opposite two end walls, said two inwardly folded marginal portions of one end wall being movable outward together with the appertaining marginal portions of the adjacent end walls from their position between the latter to asecond position wherein said marginal portions of the three said end walls establish a combined opening and pour spout, said sidewalls, bottom and gable top closure means of the package being erected from a blank comprising a basic layer of paper or cardboard coated with a thermoplastic layer such that the thermoplastic layer forms the inside surface of the package, and said end'wall which is movable outwardly to establish said opening and pour spout being provided with a transverse cut extending below the outer edge thereof for substantially the entire width of the end wall and which penetrates through only the thermoplastic layer to the surface of the underlying basic layer, andmeans establishing a differential adhesive characteristic between said layer of thermoplastic material and said underlying basic layer on said end wall such that the marginal portion thereof between said transverse cut and-the outer edge is less strongly adhered to the basic layer than is the remaining portion, and

the adhesion betwee'n'said thermoplastic layenon said marginal portion-and said underlying basic layer is less than the adhesion between said thermoplastic layer v and the thermoplastic layer on the marginal portions of the adjacent end walls to which it is sealed when said gable top is closed whereby when said inwardly folded marginal portions of said end wall are moved outwardly to said second position to establish the opening and pour spout the thermoplastic layer on said marginal portion of said c ndwall from said cut to the outer edge thereof will remain adhered to the thermoplastic layer on the marginal portions of the adjaeent'end walls and simultaneously be pulled away from the underlying basic layer.

2. A package of the gable top type as defined in claim 1 wherein said means establishing said differential adhesive characteristic is constituted by a coating of a silicon composition applied between the thermoplastic layer and the underlying basic layer.

3. A package of the gable top type as defined in claim I wherein said means establishing said differential adhesive characteristic is constituted by a coating of wax applied between the thermoplastic layer and the underlying basic layer.