EP1670690B1

EP1670690B1 - Container

Info

Publication number: EP1670690B1
Application number: EP04775486A
Authority: EP
Inventors: Per Gustavsson; Peter Marbe; Bengt Jönsson
Original assignee: Eco Lean Research and Development AS
Current assignee: Eco Lean Research and Development AS
Priority date: 2003-10-02
Filing date: 2004-09-29
Publication date: 2008-08-27
Anticipated expiration: 2024-09-29
Also published as: ES2311855T3; SE526951C2; PL1670690T3; CN1860066A; ATE406318T1; DE602004016191D1; SE0302632D0; US20080230549A1; WO2005030598A1; SE0302632L; EP1670690A1; CN1860066B

Abstract

A container of a collapsible type for liquid contents, comprising a compartment ( 4 ) which is defined by two opposite side walls ( 2 ) and a bottom wall ( 3 ) and whose volume depends on the relative position of the walls ( 2, 3 ). The container comprises a product-enclosing portion ( 19 ) which is formed by said walls ( 2, 3 ) and which in a filled state of the container extends from said bottom wall ( 3 ) to a surface level ( 20 ) of the contents held in the container. The product-enclosing portion ( 19 ) is arranged to be expanded by said contents to essentially assume the shape of a truncated cone ( 21 ) with its narrow end facing away from said bottom wall ( 3 ).

Description

Field of the Invention

The present invention relates to a container for liquid contents and, more specifically, such a container of a collapsible type, comprising a compartment which is defined by two opposite side walls and a bottom wall and whose volume depends on the relative position of the walls.

Background Art

Liquid products, such as dairy products, juice or wine, can be packed in a number of different containers.
An increasingly frequently used container is of the type described by way of introduction and has great advantages since it can be manufactured at a relatively low cost. By choosing a suitable container material, such as a laminate material with a core layer of mineral-filled polyolefin, the container can also be made to exhibit environmentally advantageous properties. The fact that the container is of a collapsible type, i.e. that the volume of the container decreases as the contents of the container are being emptied, also implies that the exposure of the contents held in the container to air is minimised, which has a positive effect on the keeping qualities of the product.
A container of said type is known from, for example, WO9941155 , WO0226567 or EP0864508 .
A drawback in some packages of this type is that in the filled state they have a tendency towards wrinkling.
Such wrinkling has a negative effect on the shape and appearance of the container and may, if the worst comes to the worst, result in wear on the side walls of the container and an indication involving a risk of leakage.
In order to counteract said tendency towards wrinkling, it is known from WO02085729 to arrange a stiffening, gas-filled duct along at least one side of the container.
It is also known from, for instance, EP 0 989 069 and EP 0 541 821 to form stiffening means which extend over the side walls of the container.

Summary of the Invention

In view of that stated above, it is an object of the present invention to provide an alternative container of the type described by way of introduction, in which container the tendency towards wrinkling is reduced.
To achieve this object, and also other objects that will appear from the following description, a container is provided according to the present invention, having the features as stated in claim 1. Preferred embodiments of the container will be evident from claims 2-6 which are dependent from claim 1.
More specifically, a container of a collapsible type for liquid contents is provided according to the present invention, comprising a compartment which is defined by two opposite side walls and a bottom wall and whose volume depends on the relative position of the walls. The container comprises a product-enclosing portion which is formed by said walls and which in a filled state of the container extends from said bottom wall to the surface level of the contents held in the container. The product-enclosing portion is adapted to be expanded by said contents to essentially assume the shape of a truncated cone with its narrow end facing away from said bottom wall.
As a result, a container is provided, which in a filled state can be made not to have a tendency to wrinkle. It is assumed that it is the frustoconical shape with the wider end of the product-enclosing portion facing downwards that causes the contents held in the container to expand the side walls of the container in a manner that counteracts wrinkling.
The product-enclosing portion can in its expanded state be essentially elliptic in cross-section.
In one embodiment, said side walls are joined along an upper connecting portion, which in the area of said product-enclosing portion has opposite boundary lines, which face the compartment and which in an empty and flat state of the container taper away from the bottom wall of the container. By the boundary lines of the product-enclosing portion being given this design, it will be possible to ensure that the shape tapering away from the bottom wall is maintained in the filled state of the container. The boundary lines can taper towards the compartment in a curved manner in the flat and empty state of the container.
In another embodiment, the ratio of the width of said bottom wall to the length thereof does not exceed 1/2. In fact it has been found that ratios exceeding 1/2 may result in a bottom wall which in the filled state of the container is not expanded in an optimal manner and which therefore causes wrinkle-promoting tensions in the container walls.
In yet another embodiment, the side walls are joined to the bottom wall along a lower connecting portion each, each connecting portion comprising end portions facing away from each other and connecting, at an obtuse angle α, to the upper connecting portion on an associated side of the container in a flat and empty state thereof, in which state said bottom wall is folded in two. The end portions may be designed in such a manner that in the expanded state of the product-enclosing portion they connect to the upper connecting portion at an angle α not exceeding 180°. By designing the end portions as bevels of the container in the unfilled state thereof which connect to the upper end portion at an angle of less than 180° in the filled state of the container, the risk of wrinkling in the transition between the upper and the lower connecting portions is significantly reduced.
In one more embodiment, said end portions are designed so as to be arranged, in the expanded state of the product-enclosing portion, along the circumferential surface of the thus formed frustoconical shape of said product-enclosing portion. It is assumed that the extent of the end portions along said circumferential surface counteracts the presence of wrinkle-promoting tensions in the walls of the container.
A preferred embodiment of a container according to the present invention will now be described by way of example with reference to the accompanying drawings.

Brief Description of the Drawings

Fig. 1a is a side view of an inventive container in an empty state.
Fig. 1b is a cross-sectional view along line I-I in Fig. 1a.
Fig. 2a is a side view of the container in Fig. 1a in a filled state.
Fig. 2b is a cross-sectional view along line II-II in Fig. 2a.
Fig. 3 is a perspective view of the container in Fig. 2a.

Description of Embodiments

Figs 1 a and 1b, to which reference is made, illustrate an inventive container 1 in an empty and flat state.
The container 1 comprises two opposite side walls 2 and a bottom wall 3. which in the shown state of the container 1 is folded in two. The walls 2, 3 define a compartment 4.
The side walls 2 are joined to each other along an upper connecting portion 5.
Said upper connecting portion 5 defines on a first side 6 of the container 1 a handle portion 7. The handle portion 7 can be designed in various ways, and in the embodiment illustrated it is designed as a duct 8 that can be filled with gas to produce an easy-to-grip handle which besides helps to stiffen the container 1 in the filled state.
The upper connecting portion 5 further defines a filling duct 9 which at its end facing away from the compartment 4 is sealed by an end seal 10 included in the upper connecting portion 5. For filling of the container 1, said end seal 10 is removed, after which a filling tube (not shown) can be introduced through the filling duct 9 into the compartment 4 of the container 1 for filling of the same. Finally the filling duct 9 is resealed.
The container 1 also comprises a spout-forming portion 11 at the upper coner of a second side 12 of the container 1 opposite to said first side 6. For opening of the container 1, an end tab 13 is removed from said spout-forming portion 11, after which the contents held in the container 1 can be poured out. The end tab 13 is removed by cutting, tearing or the like. If the end tab 13 is arranged to be torn off, the container 1 may have a tear initiation 14 that facilitates tearing off.
Each side wall 2 is further joined to the bottom wall 3 along a lower connecting portion 15, each connecting portion comprising end portions 16 which are facing away from each other and connect to the upper connecting portion 5 on the associated side 6, 12 of the container 1.
By the walls 2, 3 being joined to each other is meant that the walls 2, 3 are joined by a sealing process, such as welding, gluing or the like.
Each lower connecting portion 15 can also, like in the shown embodiment of the inventive container 1, comprise an intermediate portion 17 located between the two end portions 16. However, it is also possible to form all walls 2, 3 in a single piece folded in the shape of a W, thus making it possible to leave out said intermediate portion 17 since each side wall 2 will pass into said bottom wall 3 in precisely these parts of the container 1.
The walls 2, 3 thus define a compartment 4 which in the empty and flat state of the container 1 has a non-existent volume (for the sake of clarity, the side walls 2 of the container 1 are shown slightly separated in Fig. 1b). The compartment 4 is further sealed in said state and can thus be sterilised in connection with the manufacture of the container 1 and, with maintained sterility, be distributed to the location of filling the container 1.
The volume of said compartment 4 depends on the relative position of the walls 2, 3, and in Figs 2a and 2b, to which reference is now also made, the container 1 has been filled with liquid contents 18, whereby the walls 2, 3 of the container 1 have assumed a relative position for defining a compartment 4, whose volume essentially corresponds to the supplied contents 18. It will be appreciated that a small air-filled volume may be formed just above a surface level of the contents 18 held in the compartment 4 of the container 1. For the sake of clarity, this air-filled volume is highly exaggerated in Fig. 2b.
The inventive container 1 is designed so that its tendency to wrinkle in the filled state is reduced.
To this end, the container 1 has a product-enclosing portion 19 which is formed by the walls 2, 3 of the container and which in the filled state of the container extends from said bottom wall 3 to a surface level 20 of the contents 18 held in the compartment 4 of the container 1.
The product-enclosing portion 19 is arranged to be expanded by said contents 18 to essentially assume the shape of an elliptic, truncated cone with its wide end facing the bottom wall. The shape of the product-enclosing portion 19 is illustrated in Fig. 3, to which reference is now also made, by the truncated cone 21 drawn in this Figure. In fact it has surprisingly been found that such a design of the product-enclosing portion 19 effectively counteracts wrinkling.
It is assumed that the frustoconical shape, with the wide end of the product-enclosing portion 19 facing downwards, makes the contents 18 held in the container expand the side walls 2 of the container 1 in a manner which counteracts the presence of tensions in the walls 2, 3 of the container and which thus reduces the tendency of the container 1 to wrinkle.
As stated above, said product-enclosing portion 19 is in the embodiment illustrated arranged to essentially assume the shape of an elliptic, truncated cone 21, However it will be appreciated that the shape can be allowed to deviate somewhat from said conical shape. For instance, it may in some cases be desirable to let the upper narrow end diverge somewhat to produce a projecting spout-forming portion 11 of the container 1.
To provide said frustoconical shape of the product-enclosing portion 19, the upper connecting portion 5 of the container 1 is designed in such a manner that, in the area of said product-enclosing portion 19, it has opposite boundary lines 22 which are facing the compartment 4 and extended in a tapering manner away from the bottom wall 3 when the container 1 is in a flat and empty state. The boundary lines 22 can advantageously taper towards the compartment 4 in a curved manner in said direction.
The tapered shape is required because a bottom width B1 of the container 1 will be contracted during filling of the container 1 while an upper width 82 of the container 1 will be affected to a considerably smaller extent. This is quite obvious when comparing Figs 1 a and 2a. It is especially apparent from Fig. 2a that the tapering extent of the boundary lines 22 is maintained in the filled state of the container 1, but to a smaller extent than in the flat and empty state of the container 1 (Fig. 1a).
In accordance with that illustrated in Fig. 1a, each end portion 16 of the respective lower connecting portion 15 connects to the upper connecting portion 5 at an obtuse angle α. In the filled state of the container 1 (Fig. 2a), the angle α, projected in the plane shown in Fig. 2a, is still obtuse, whereby the tendency of the container 1 to wrinkle is further reduced. By ensuring that said angle α does not exceed 180°, it is in fact guaranteed that an undesirable wrinkle is not formed in the transition between the respective end portions 16 and the upper connecting portion 5.
Another factor that promotes the forming of a container 1 which is not inclined to wrinkle is the design of said end portions 16 so that these end portions, in the expanded state of the product-enclosing portion 19, are arranged along the circumferential surface of the thus formed frustoconical shape of said portion 19.
Also the design of the bottom wall 3 has been found to be important for the tendency of the container 1 to wrinkle. It has been found advantageous to design the bottom wall so that the ratio of its width to its length does not exceed 1/2. It has been found that ratios exceeding this quota result in a wrinkle on each side wall at a short distance from the bottom wall. It will be appreciated that there is also a lower limit of the ratio of the width of the bottom wall to its length, but this lower limit is more important for the stability of the filled container than for its tendency to wrinkle.
The length of the bottom wall 3 corresponds to the width B1 of the container in the unfilled state and the width of the bottom wall 3 thus is the measure transversely of said length in the filled state of the container, as shown in Fig. 2b.
These two latter designs of the container 1 are assumed to counteract the presence of wrinkle-promoting tensions in the walls 2, 3 of the container 1.
As mentioned above, the shown embodiment of an inventive container 1 has a gas-filled handle. It will be appreciated that this stiffening handle additionally helps to provide a container 1 which is not inclined to wrinkle in its filled state.
The inventive container 1 thus has a number of designs, which each help to provide a container 1 which is not inclined to wrinkle. It is possible that some of these designs themselves are not sufficient, and that it is necessary for the designs to appear together in order to provide a container 1 which is not inclined to wrinkle.
However, it appears from the observations made as if the frustoconical shape of the product-enclosing portion 19 of the container 1 has the greatest effect to counteract the general presence of wrinkles.
According to the present invention, a container 1 is thus provided, whose tendency to wrinkle in the filled state is reduced.
More specifically, this is achieved in such a manner that a product-enclosing portion 19 formed by the walls 2, 3 of the container 1 is arranged to be expanded by contents 18 held in the container 1 to essentially assume the shape of a truncated cone 21 with the wide end facing downwards, in which case said product-enclosing portion 19 is preferably given an elliptic cross-section. This design of the container 1 has been found efficient for reducing wrinkles in the container 1.
In order to additionally reduce the tendency towards wrinkling, it has been found advantageous to arrange the end portions 16 of the lower connecting portions 15 of the container 1 in such a manner that the lower connecting portions in the filled state of the container 1 connect to the upper connecting portion 5 on the associated side 6, 12 of the container 1 at an obtuse angle α that does not exceed 180°. This prevents the special wrinkling that may occur in the transition from the lower connecting portions 15 to the upper connecting portion 5. Wrinkling is also counteracted by designing the end portions 16 so as to be arranged along the circumferential surface of the product-enclosing portion 19 which in the filled state of the container 1 is frustoconical.
Additional means for counteracting wrinkling comprise designing the bottom wall 3 of the container 1 in such a manner that its width is to its length as maximum 1 to 2.
It will be appreciated that the present invention is not limited to the embodiment shown. Several modifications and variations are conceivable, which means that the invention is exclusively defined by the appended claims.

Claims

A container of a collapsible type for liquid contents, comprising
a compartment (4) which is defined by two opposite side walls (2) and a bottom wall (3) and whose volume depends on the relative position of the walls (2, 3), and

a product-enclosing portion which is formed by said walls (2, 3) and which in a filled state of the container extends from said bottom wall (3) to a surface level (20) of the contents held in the container,
wherein the container exhibits a bottom width (B1) which in the filled state of the container is greater than a an upper width (B2) of the container, and
wherein the product-enclosing portion (19) is arranged to be expanded by said contents to essentially assume a shape defined by the geometric configuration of said walls, whereby the product-enclosing portion (19) in the filled state of the container assumes the shape of a truncated cone (21) with its narrow end facing away from said bottom wall (3),
characterised in that
the side walls (2) are joined along an upper connecting portion (5), which in the area of said product-enclosing portion (19) has opposite boundary lines (22), which are facing the compartment and which in an empty and flat state of the container taper away from the bottom wall (3) of the container,
wherein said boundary lines (22) have a concave curvature, seen from outside of the container, and taper towards the compartment (4) in a curved manner.
A container as claimed in claim 1, in which said product-enclosing portion (19) in the expanded state is essentially elliptic in cross-section.
A container as claimed in claim 1 or 2, in which the ratio of the width of said bottom wall (3) to the length thereof does not exceed 1/2.
A container as claimed in any one of claims 1-3, in which the side walls (2) are joined to the bottom wall (3) along a lower connecting portion (15) each, each connecting portion comprising end portions (16) facing away from each other and connecting, at an obtuse angle (α), to the upper connecting portion (5) on the associated side (6, 12) of the container in a flat and empty state thereof, in which state said bottom wall (3) is folded in two,
A container as claimed in claim 4, in which said end portions (16) are designed so as to connect, in the expanded state of the product-enclosing portion (19), to the upper connecting portion (5) at angle (α) not exceeding 180°.
A container as claimed in claim 4 or 5, in which said end portions (16) are designed so as to be arranged, in the expanded state of the product-enclosing portion (19), along the circumferential surface of the thus formed frustoconical shape of said product-enclosing portion (19).