WO2012070075A1

WO2012070075A1 - Container with walls obtained by bending one or more sheets of flexible material comprising an improved closure device

Info

Publication number: WO2012070075A1
Application number: PCT/IT2010/000470
Authority: WO
Inventors: Pasquale Cocchioni
Original assignee: Diva International S.R.L.
Priority date: 2010-11-24
Filing date: 2010-11-24
Publication date: 2012-05-31
Also published as: EP2643240A1

Abstract

The invention describes a container (1) comprising: - a container main body (2) formed from walls (3-8) obtained by bending at least one sheet of flexible material, the walls (3-8) comprising at least one first wall (3) in which an access opening (23) to the internal space (9) is defined, - a closure device (10) comprising a support base (11) in which a withdrawal opening (13) is defined facing the access opening (23), the closure device (10) also comprising a cover (12) coupled with the support base (11) and made as a distinct piece from the support base (11). At least one from the support base (11) or the cover (12) comprises a first collar (40) that surrounds the withdrawal opening (13), the first collar (40) comprising first snap locking elements (43) distributed around the withdrawal opening (13), the closure device (10) also comprising an elastically deformable compression sealing element (41) and comprising at least one sealing portion surrounding the withdrawal opening (13).

Description

Container with walls obtained by bending one or more sheets of flexible material comprising an improved closure device

DESCRIPTION

The present description concerns the technical field of packaging and it refers in particular to a container with walls obtained by bending one or more sheets of flexible material and comprising an improved closure device .

In the technical field of packaging for objects or food, it is known to use containers having walls formed by bending and welding one or more sheets of flexible material.

For example, containers of the aforementioned type are known for wet or impregnated tissues, made by bending a single flexible sheet upon itself and around the material to be packaged to form four consecutive walls in opposite and spaced apart pairs of the container and by carrying out two thermowelding operations to make two further closed walls, opposite one another and spaced apart, of the container. One of the walls of the container has an associated closure device made from relatively stiff plastic material having a reclosable cover, i.e. that can be repeatedly opened/closed to allow/prevent access to a withdrawal opening communicating with the inside of the container itself.

Containers of the aforementioned type, also known as "pillow packs" or "flow packs" or "flow wrap", have the advantage of being relatively cost-effective, of being relatively small in size and of being practical to use.

Although widely used, containers with flexible walls of the type described above do not have satisfactory performance in terms of air-tightness.

Indeed, it has been observed that the containers of the prior art have reclosable closure devices that do not ensure a satisfactory hermetic closure. For this reason, for example in the specific case of containers for wet or impregnated tissues, the substance that impregnates or wets the tissues tends to progressively evaporate. There is therefore a progressive deterioration of the quality of. the tissues. It has also been observed that the performance in terms of seal of the containers of the prior art worsen after repeated opening and closing cycles of the closure device.

Patent application US 2003/159403 describes a container with flexible walls of the state of the art of the type described above and as defined in the preamble of. the first claim. Although in such a document . the described container is defined as hermetic it is wished to improve the performance in terms of seal of the closure device. Moreover, such a document describes a container in which the cover is made integrally with a base part of the closure device in which the withdrawal opening is defined. This in some cases makes it relatively complex to make the closure device by moulding.

Document FR 2814348 describes a container with stiff walls that is not hermetic, in which the cover is made as a distinct piece from the body of the container. The body of the container is provided inside the withdrawal opening with a seat in which an appendix of the cover can be engaged, provided to couple the cover with the body of the container. Such an appendix is hinged to the cover. In 'this way it is possible, as represented in figure 2 of the same document FR 2814348 to reduce the visual impact of the hinge, but this expedient involves substantial complications if it is wished to make the described container hermetic.

A purpose of the present description is to provide a container that is able to avoid the drawbacks described above with reference to the containers of the prior art and that in particular has increased air-tightness and can be made through relatively simpler moulding.

This purpose is accomplished through a container as defined in general in the attached claim 1. Advantageous embodiments of a container according to the present invention are defined in the attached dependent claims.

Further characteristics and advantages of the invention will become clearer from the following detailed description, made purely as a non-limiting example, with reference to the attached drawings, in which:

^■ - figure 1 is a perspective view of a container made by bending one or more sheets of flexible material and comprising a closure device comprising a mobile cover shown in closed position;

- figure 2 is a further perspective view of the container of figure 1, in which the cover is shown in open position;

- figure 3 is a side section view along the axis Y-Y of the container of figure 1;

- figure 4 is a perspective view from above of. the closure device of figure 1, in which the closure device is. shown with the cover in open position;

- figure 5 is a side section view (section Y-Y of figure 4) of a part of the closure device of figure 4, in which the cover is shown in open position;

- figure 6 is a side section view (section Y-Y. of figure 4) of a part of the closure device of figure 4, in which the cover is shown in closed position; - figure 7 shows a perspective view from above of a possible variant embodiment of the closure device;

- figure 8 schematically shows some steps of. a ^■process for making the container represented in figures 1-6.

With reference to the attached figures, a container comprising a main body 2 formed from walls 3-8 obtained by bending at least one sheet of flexible material and defining an internal container space 9 has been globally indicated with 1. The container 1 in particular comprises an upper wall 3, .an opposite lower wall 4 and four side walls in opposite pairs 5,6 and 7,8.

^•■One of the aforementioned walls, in the example _'the upper wall 3, is provided with an access opening 23 to ,the internal space 9. In the example represented in .the figures, the access opening 23 is approximately quadrangular in shape with bevelled corners and slightly rounded sides.

„ In accordance with a non-limiting embodiment, the container 1 is a container made:

·.^'-^' by bending a single flexible sheet upon itself and around a content to be packaged to form firstly a tubular ..casing having four consecutive walls 3,4,5,6 in opposite pairs and spaced apart and having two open ends; and

- by carrying out two welding operations, for example thermowelding, to close the aforementioned.^" open ends and make two further closed walls 7, 8, opposite one another and spaced apart.

Te flexible sheet is for example, without for this reason introducing any limitation, a multi-layer sheet consisting of three coupled sheets, like for example an inner sheet of polyethylene, an intermediate sheet of aluminium and an outer sheet of plastic film. More preferably, the container 1 is a "pillow pack" or a "flow pack" or a "flow wrap".

Henceforth we will refer to a non-limiting embodiment in which the container 1 is a pillow pack or a flow pack or a flow wrap, obtained by bending a single sheet of flexible material, and in particular a container for a: plurality of wet tissues 20 intended to be housed one on top of the other inside the container 1, as represented in figure 3.

The container 1 comprises a closure device 10,„made from at least one relatively stiff material, comprising a support base 11, preferably but not limitingly having an essentially plate-shaped main body 14 coupled with the upper wall 3 of the container 1.

In accordance with an embodiment, as represented in the examples in the figures, the essentially plate-shaped main body 14 is arranged inside the internal space 9 and is coupled with the upper wall 3 on the side 3' thereof facing towards the internal space 9. More preferably, the plate-shaped main body 14 is coupled with the upper wall 3 by welding, advantageously through thermo-welding, an edge of the access opening 23 to the underlying opposite portion of the plate-shaped main body 14.

The plate-shaped main body 14 is preferably made from polypropylene and more preferably from high-density polypropylene .

Inside the support base 11 a withdrawal opening 13 is defined that has smaller dimensions than the access opening 23, which is arranged facing the access opening 23, on the same plane or on a different plane, for example in a substantially centred position with respect to the latter. In the particular example represented in the^', figures, the withdrawal opening 13 is essentially circular in shape. In a possible alternative embodiment, the. withdrawal opening 13 is substantially elliptical or oval in shape.

In accordance with an embodiment not shown in the figures, the withdrawal opening 13 could be initially blocked by an irreversibly removable cap with a tongue made integrally with the support base 11, the latter being connected through weakened lines intended to be torn . The closure device 10 also comprises a mobile cover 12 operatively coupled with the support base 11 and suitable for being moved with respect to it to allow or prevent access from the outside to the withdrawal opening 13. Such a cover 12 is for example rotatably hinged to the support base 11. In the figures the hinging line of the cover 12 has been indicated with 16.

, In an embodiment, the cover 12 is made in a distinct piece, from the support base 11 and is coupled with the latter through at least one interlocking coupling element 19 provided in the cover 12. More preferably, the support base 11 comprises a interlocking coupling pocket 18 accessible from an opening arranged laterally with respect to the withdrawal opening 13 and arranged outside /.of the withdrawal opening and having an opening axis parallel to the opening axis Z-Z of the withdrawal opening 13. The cover 12 comprises an interlocking Coupling element in the form of a fixed appendix 19 having a connection portion received inside the pocket 18 being axially engaged inside the latter. In practice,- the fixed . appendix 19 is intended not to move with respect to the support base 11 during the opening/closing of the cover 12. In accordance with an embodiment, the fixed appendix 19 is firmly locked in the pocket 18 and is separated from the remaining part of the cover 12 by the hinging line 16. The pocket 18 is isolated from the internal space 9 of the container 1 as no fluid communication passage is foreseen in the inner walls of the pocket 18 suitable for placing the inside of the pocket 18 in communication with the internal space 9. More, preferably, the pocket 18 is isolated from the internal space 9 even when the fixed appendix 19 of the cover 12 is not engaged in the pocket 18.

Ih accordance with a currently preferred embodiment, the pocket 18 and the fixed appendix 19 of the cover are the same length, or roughly the same length, as the side 34 of the cover 12 hinged to the fixed appendix 19.

In accordance with an embodiment, as represented ' in the_. figures, the interlocking coupling of the fixed appendix in the pocket 18 is obtained by shape coupling between an outer surface of the fixed appendix 19 and an inner surface of the pocket 18. Indeed, it should be observed how one of the inner surfaces of the pocket comprises a projection 30 and how the opposite outer surface of the fixed appendix 19 comprises an undercut 31 suitable for cooperating with the projection 30 to lock the interlocking element 19 in the pocket 18. Preferably, the projection 30 and the undercut 31 are roughly- the same length as the side of the cover hinged to the hinge 16.. In accordance with a particularly preferred embodiment, the outer surface of the appendix 19 is the outer surface of a wall that continuously surrounds a recess inside the interlocking appendix and facing the pocket 18.

With reference to figures 3 and 4, in accordance with a non-limiting embodiment the support base 11 also comprises a first and a second tab 15 hinged to the plate-shaped main body 14 along two peripheral edges thereof 25 arranged on opposite sides with respect to the withdrawal opening 13.

In accordance with an embodiment the tabs 15 are two ■ panels, preferably quadrangular, rotatably hinged to the plate-shaped main body 14. Advantageously, the tabs 15 are made integrally in a single piece with the plate- shaped main body 14 and are connected to the latter through^; a respective weakened line 25 of reduced thickness, for example obtained by moulding or by a subsequent incision operation, which represents a hinging line around which the tabs 15 can be rotated with respect to the plate-shaped main body 14. As can be seen from what^' is represented in figure 3, when the support base 11 is coupled with the container 1 the tabs 15 are oriented substantially perpendicular to the plate-shaped main body 14. In the operative configuration represented in figure 4 it can, on the other hand, be seen how the tabs 15 are coplanar to the plate-shaped main body 14. Thanks to the provision of the tabs 15 the container has a more stable shape than containers of the prior art. Indeed, it is possible to set a container of the type described above on a support plane, like for example a sales display rack, reducing the probability of such a container accidentally knocking over. This embodiment is particular advantageous for containers having relatively large dimensions. It should also be observed that a container of the type described above maintains a certain degree of shape stability even when its content is progressively emptied.

In accordance with an embodiment, the support base 11 comprises a lowered seat 35, i.e. arranged at a^' lower height than the plate-shaped main body 14, which surrounds the withdrawal opening 13. More preferably, the lowered seat 35 is surrounded by a projecting frame 36. Such a projecting frame 36 projects beyond the upper wall 3 of the container when the closure device 10 is associated with the container 1.

In accordance with an embodiment, as illustrated in figure 1, the cover 12 when it is in the closed position is arranged flush with the upper edge of the projecting frame 36 and is shaped so that on the opposite side with respect to the hinge 16 an ergonomic essentially lune- shaped recess, provided for easier gripping and opening of the cover 12, is defined between the cover 12 and the frame 36. In accordance with an embodiment, the fixed appendix 19 of the cover also has an upper wall that, when - the appendix 19 is engaged in the pocket 18, is flush with the frame 36.

In the closure device 10, at least one from the support base 11 or the cover 12 comprises a first collar 40 that surrounds the withdrawal opening 13, the first collar 40 comprising first snap locking elements distributed around the withdrawal opening 13 and suitable for holding the cover 12 in the closed position cooperating with matching second interlocking elementsprovided on the other from the support base 11 and the cover 12.

In the particular example represented, the first collar 40, essentially circular in shape, is provided on the support base 11 and in particular it projects towards the cover 12 from inside the lowered seat 35. In an alternative embodiment, the first collar 13 could project from the inner face of the cover 12.

In accordance with the embodiment represented in figures 1 to 6, the first snap locking elements 43 are provided on an outer side wall of the collar 40 and the matching interlocking elements 42 project from the cover 12 towards the first collar 40 when the cover 12 is in closed position.

In the particular example represented, the first snap locking elements comprise a continuous projecting edge 43 that projects from the side wall 48 of the collar 40 to define an undercut. Similarly, the matching interlocking elements 42 comprise a second collar 42 projecting from the cover 12 that on the inner side wall has a continuous projecting edge 44. In practice, the second collar 42 is suitable for being snap-fitted by shape coupling around the first collar 40, as can be clearly seen in figure 6. It should be observed that the snap locking elements 42 and 43 are distributed around the withdrawal opening 13, and in this example they surround it with continuity. In accordance with an _: alternative embodiment the snap locking elements 42 and 43 could be many discrete and separate elements distributed around the withdrawal opening 13. It should be observed that the positions of the first 40 and second 42 collar can be inverted.

. The closure device 10 also comprises an elastically deformable compression sealing element and comprising at least one sealing portion 41 surrounding the withdrawal opening 13 and suitable for being axially clamped and compressed in closed position between an abutment surface 45 of the first collar 40 and an opposite portion of the cover 12. For the purposes of the present description by axial direction we mean a direction parallel to the_. axis Z-Z of the withdrawal opening. In the alternative embodiment in which the first collar 40 is provided on the cover 12 instead of on the base 11, the sealing portion is intended to be clamped and compressed between the abutment surface 45 of the first collar 40 and ^" an opposite portion of the support base 11. ■ '

In accordance with a preferred embodiment, the sealing element comprises a gasket 41, preferably circular and inside the second collar 42, fixedly connected to the cover 12 and that surrounds the , withdrawal opening 13 when the cover 12 is in closed position. In accordance with an advantageous embodiment, the gasket 41 is made from an elastomer integrally with the cover 12 through a bi-material moulding technique. For this purpose, with reference to figure 5, it. is possible to provide in the cover 12 a recess 47 suitable for at least partially receiving the gasket 41.

In accordance with an alternative embodiment,^" the gasket 41 instead of being coupled with the cover 12 is associated with the support base 11.

In accordance with an embodiment, the abutment surface 45 of the first collar 40 comprises one or more raised elements 46 with respect to a remaining portion of the abutment surface 45 suitable for locally compressing a deforming the sealing element 41. In the particular example represented, the abutment surface 45 is a surface of a circular crown wall 47 that extends perpendicularly to the opening axis Z-Z from the side wall 48 towards the inside of the collar 40, in practice forming an L-shaped profile with such a side wall 48. In the same example, the aforementioned raised elements 46 are in the form of three concentric continuous ridges 46 that surround the withdrawal opening 13. Of course, the circular shape of the ridges, of the collar and of the abutment surface, can be replaced with an elliptical or oval shape or by a less preferred quadrangular or in general polygonal shape .

^; In accordance with an alternative embodiment not represented in the figures, the first collar 40 is included in the support base 11 and the sealing element is represented by the same cover, and the sealing portion is a portion of the same cover opposite the first collar 12, and in particular opposite the abutment surface 45. This can be obtained by making the cover 12 from a relatively elastic material with respect to the material from which the support base 11 is made. For example, it is advantageously possible to make the support base 11 from polypropylene, preferably high-density polypropylene, and to make the cover 12 from polypropylene loaded with rubber, preferably with a percentage rubber at least equal to 35% and more preferably equal to 40%.

Figure 7 represents a variant embodiment of a closure device 10, which differs from the closure device described with reference to figures 1-6 in that the first snap locking elements comprise a plurality of recesses/ through openings 51 provided on the upper wall 47 of the first collar 40 and arranged between the withdrawal opening 13 and the abutment surface 45 and in that he matching interlocking elements comprise a plurality of hooks 50 that project from the cover 12 towards the first collar 40 to be received in the closed position in respective recesses or through openings 51. Preferably, as represented in figure 7 the recesses or openings 50 and the hooks 51 are evenly distributed around the withdrawal opening. In this particular example there -are pairs of elements in diametrically opposite positions.

Also in the embodiment of figure 7 there is, for example, a gasket 41 integral with the cover 12 and made together with it through bi-material moulding. In an alternative embodiment, as already explained earlier, the gasket 41 may not be foreseen and the seal can be ensured by making the cover 12 from relatively more flexible material with respect to the support base 11 as described above. Finally, in a further alternative embodiment, it is possible, with respect to what is represented in figure 7, to foresee the first collar 40 associated with the cover.12 and the hooks 50 and the gasket 41 associated wit. le support base 11.

With reference to figure 8, an example of a process for making a container 1 of the type described above will be described hereafter.

In an initial step a sheet of flexible material is provided, having a substantially quadrangular shape with peripheral edges in parallel pairs 71-74. Such a sheet 70 is for example a portion of a continuous and flexible flat band that extends along a direction of prevalent longitudinal extension, which is in practice the^' flow direction of the machine adapted to carry out. , the process .

The process foresees a step of making an opening or a weakened line on the sheet 70 to make the access opening 23 inside the sheet 70.

' The process also comprises a step of resting the closure device 10 on the sheet 70 so that the access opening 23 or weakened line is substantially centred with respect to the access opening 13 of the closure device 10. In such a step the tabs 15 are oriented on the .same plane with respect to the plate-shaped main body 14 and are therefore substantially parallel to the plane of the sheet 70.

Advantageously, in the process there is a step of coupling the closure device 10 with the sheet 70, for example through a thermo-welding device 75.

Preferably, the process comprises a step of resting a content 20 for packaging inside the container, for example a pile of wet tissues, on the plate-shaped main body 14.

The process also comprises a step of bringing together two opposite peripheral edges 71, 73 of the sheet 70, intended to be joined to one another to form a tubular casing in which the sheet 70 is wound around the content 20 to be packaged, said bringing together, being such as to pull and rotate the tabs 15 so that they tend to orient themselves perpendicularly with respect to the plate-shaped main body 14.

^■The process also comprises a step of joining (for example by thermo-welding) together the edges that .have been. brought together 71, 73 as described in the previous step¹ to form a tubular casing having two open end portions and a step of closing said open end portions, preferably through a thermo-welding operation, to form a closed container.

From what has been described above, it is therefore possible to understand how a container of the type described above makes it possible to avoid or reduce the drawbacks described above with reference to containers of the prior art.

Without affecting the principle of the invention, the embodiments and the details can be widely varied with respect to what has been described and illustrated purely as a non-limiting example, without for this reason departing from the scope of the invention as defined in the attached claims. For example, although a container for wet tissues has been described in particular, it should be noted that the teachings of the present description can be applied to containers with flexible walls of a different type, even for food use, like for example, without for this reason introducing ^' any limitation, containers for coffee or granulated, or powdered substances, etc.

Claims

1. Container (1) comprising:

- a container main body (2) formed from walls (3-8) obtained by bending at least one sheet of flexible material and defining an internal space (9) of .the container, the walls (3-8) comprising at least one first wall (3) in which an access opening (23) to the internal space (9) is defined,

- a closure device (10), made from one or more relatively stiff material with respect to said flexible material, comprising a support base (11) in which a withdrawal opening (13) is defined facing the access opening (23) , the withdrawal opening having an opening axis (Z-Z) perpendicular to the plane of the withdrawal opening, the closure device (10) also comprising a cover (12) .coupled with the support base (11) provided for opening/closing the withdrawal opening (13),

wherein at least one from the support base (11) or the cover (12) comprises a first collar (40) that surrounds the withdrawal opening (13), the first collar (40) comprising first snap locking elements (43) distributed around the withdrawal opening (13) and suitable for holding the cover (12) in closed position cooperating with matching second locking elements (42) provided on the other from the support base (11) and the cover ( 12 ) , characterised in that:

the closure device (10) also comprises an ^• elastically deformable compression sealing element_., (41) and comprising at least one sealing portion surrounding the withdrawal opening (13) and suitable for being axially clamped and compressed in closed position between an abutment surface (45) of the first collar (40) and an opposite portion of the other from the support base (11) or the cover (12) ;

- the cover (12) is made in a distinct piece from the support base (11) and is coupled with the latter through at least one interlocking coupling element (19), the. support base (11) comprising an interlocking coupling pocket (18) able to be accessed from an opening arranged on the side with respect to the withdrawal opening (13) and having an opening axis parallel to the opening axis of the latter and wherein the interlocking coupling element (19) comprises a fixed appendix (19) having a connection portion received inside the pocket (18) and axially interlocked inside the latter and separated from the remaining part of the cover (12) by a hinge line (16), the pocket (18) being outside of the withdrawal opening (13) and. isolated from the internal space (9) .

2. Container (1) according to any one of the previous claims, wherein the abutment surface (45) comprises one or more raised elements (46) with respect to a remaining portion of said abutment surface (45) and suitable for compressing and locally deforming said sealing portion.

.._.3. Container (1) according to claim 2, wherein said one or more raised elements are in the form of one or more continuous ridges (46) that surround the withdrawal opening ( 13 ) .

4. Container (1) according to any one of -the previous claims, wherein the first snap locking elements (43) are provided on an outer side wall (40) of the first collar (40) and wherein the matching locking elements (42) project from the other from said support base (11) or said cover (12) towards the first collar (40).

5.. Container (1) according to claim 4, wherein said matching locking elements (42) comprise a second collar (42) suitable for being snap-fitted by shape coupling around the first collar (40) .

6. Container (1) according to any one of claims ^"1 to 3, wherein:

the first snap locking elements comprise a plurality of recesses or through openings (51) provided on an upper wall (47) of said first collar and arranged between the withdrawal opening (13) and said abutment surface (45) ; and

- the matching locking elements comprise a plurality of hooks (50) that project from the other from said support base (11) or said cover (12) towards the first collar (40) to be received in closed position in respective recesses or through openings (51) .

7. Container (1) according to claim 6, wherein the 5 plurality of recesses or through openings (51) and the plurality of hooks (50) are uniformly distributed around the withdrawal opening (13) .

.

8. Container (1) according to any one of the previous claims, wherein the sealing element comprises a 10. gasket (41) .

9. Container (1) according to any one of the previous claims, wherein the gasket is made from an elastomer integrally with the other from said support base (11) or said cover through a bi-material moulding

15 technique.

10. Container (1) according to any one of claims 1 to 7, wherein the first collar (4) is provided in the support base (11) and wherein said sealing element is said cover (12) itself, the sealing portion being a 0 portion of the cover opposite the first collar (40), the cover (12) being made from a relatively elastic material with respect to the material from which the support base (11) is made.

11. Container (1) according to claim 10, wherein the 25 support base (11) is made from polypropylene and wherein the cover (12) is made from polypropylene loaded with a - percentage of rubber of 35% or more.

12. Container according to any one of the previous claims, wherein the support base (11) comprises an essentially plate-shaped main body (14) and also comprises a first and second tab (15) hinged to said main body (14) along two peripheral edges (25) thereof arranged on opposite sides with respect to the withdrawal opening (13) .

13. Container (1) according to claim 12, wherein the tabs (15) are two panels rotatably hinged to the plate- shaped main body (14) .

14. Container (1) according to claims 12 or 13, wherein the tabs (15) are made integrally with the plate- shaped main body (14) and are connected to it through a weakened line (25) of reduced thickness that represents a hinging line of said tabs (15) .

^•15. Container according to claim 1, wherein the pocket (18) and the fixed appendix (19) of the cover (12) are the same length, or roughly the same length as a, side (34) of the cover (12) hinged to the fixed appendix (19) .

16. Container (1) according to any one of the previous claims, wherein the container is a tubular container in which said walls are obtained by bending a single sheet of flexible material around a content to be packaged .

17. Container (1) according to any one of the previous claims, wherein said container is a "flow pack" or a "pillow pack" or a "flow-wrap".

18. Group of parts comprising a container according to any one of the previous claims and a plurality of wet or impregnated tissues and similar housed stacked one on top of the other inside said container.