Opening device for a container and a method for producing such opening device

Abstract

An opening device for a container comprises a pouring spout defining a pouring opening to pour in use the content of the container, a closing element closing the pouring opening and connected to the pouring spout by a breakable connection, and a closure fitted to the pouring spout in a removable manner to close the pouring opening at a region thereof different from that closed by the closing element; the closing element is formed in one piece with a protruding portion extending through the pouring opening and welded to the closure far away from the closing element.

Claims

1. A closure for an opening device of a container, the closure comprising a lid configured to be fitted to a pouring spout of the opening device, and welding promoting means for connecting the lid to a closing element of the opening device, the lid comprising an end wall and a cylindrical lateral wall projecting from the end wall, the cylindrical lateral wall surrounding an interior space in the lid, the end wall possessing an end surface facing toward the interior space of the lid, the welding promoting means comprise a welding promoting element distinct from the lid and permanently connected to the end surface of the end wall of the lid.

2. The closure as claimed in claim 1, wherein the cylindrical lateral wall projecting from the end wall of the lid possesses an inner surface facing the interior space in the lid, the inner surface of cylindrical lateral wall includes an interior thread that is threadably engageable with an outer thread on a neck of pouring spout of the container.

3. The closure as claimed in claim 1, wherein the lid includes an annular rib that is integral with the end surface of the end wall, the annular rib extending entirely axially towards the interior space in the lid, the annular rib surrounding a seat at which is positioned the welding promoting element.

4. The closure as claimed in claim 3, wherein the annular rib is positioned radially inwardly of the cylindrical lateral wall so that the cylindrical lateral wall surrounds the annular rib.

5. The closure as claimed in claim 1, wherein the welding promoting element comprises a sheet element including a layer of conductive material and having: a first face configured to be welded to the closing element of the opening device by heat generated by inducing an electric current in the layer of conductive material; and a second face opposite the first face and welded to the end surface of the end wall of the lid of the opening device by heat generated by inducing an electric current in the layer of conductive material.

6. The closure as claimed in claim 5, wherein the sheet element further comprises a first and a second layer of heat-sealable plastic material arranged on opposite sides of the layer of conductive material, the first layer of heat-sealable plastic material defining the first face, and the second layer of heat-sealable plastic material defining the second face.

7. The closure as claimed in claim 5, wherein the first face of the sheet element is completely exposed to the interior space in the lid.

8. A closure for an opening device of a container, the closure comprising a lid configured to be fitted to a pouring spout of the opening device and a welding promoting element that is weldable to a closing element of the opening device, the lid comprising a cylindrical lateral wall and an end wall completely closing one end of the cylindrical lateral wall, the cylindrical lateral wall projecting axially from the end wall and surrounding an interior space in the lid, at least a portion of the cylindrical lateral wall being threaded to threadably engage a thread on a neck of pouring spout of the container, the end wall of the lid possessing an end surface facing toward the interior space of the lid, the welding promoting element being permanently fixed to the end surface of the end wall, the welding promoting element comprising a conductive material layer possessing opposite surfaces including one surface facing toward the end surface of the end wall and an other surface facing toward the interior space in the lid, the end wall of the lid covering an entirety of the one surface of the conductive material layer, the other surface of the conductive material layer being covered by a heat-sealable plastic material so that upon inducing an electric current in the conductive material layer the closing element may be welded to the heat-sealable plastic material of the welding promoting element.

9. The closure as claimed in claim 8, wherein the cylindrical lateral wall possesses an inner surface facing the interior space in the lid, the portion of the cylindrical lateral wall that is threaded being the inner surface of the cylindrical lateral wall.

10. The closure as claimed in claim 9, wherein the lid includes an annular rib that is integral with the end surface of the end wall, the annular rib extending entirely axially towards the interior space in the lid, the annular rib surrounding a seat at which is positioned the welding promoting element.

11. The closure as claimed in claim 10, wherein the annular rib is positioned radially inwardly of the cylindrical lateral wall so that the cylindrical lateral wall surrounds the annular rib.

12. A method for producing a closure for an opening device of a container, the method comprising: providing a lid configured to be fitted to a pouring spout of the opening device, the lid comprising an end wall and a cylindrical lateral wall projecting from the end wall, the cylindrical lateral wall surrounding an interior space in the lid, the end wall possessing an end surface facing toward the interior space of the lid; providing a welding promoting element configured to connect the lid to a closing element of the opening device, the welding promoting element that is distinct from the lid; inserting the welding promoting element in the lid so that the welding promoting element faces the end surface of the end wall; and permanently connecting the welding promoting element to the end surface of the end wall of the lid.

13. The method as claimed in claim 12, wherein the welding promoting element comprises a sheet element including a layer of conductive material; and the permanently connecting of the welding promoting element to the end surface of the end wall of the lid is performed by inducing an electric current in the layer of conductive material to produce a localized heat adapted to weld a face of the sheet element to the end surface of the end wall of the lid.

14. The method as claimed in claim 12, wherein the end wall of the lid is a non-apertured end wall so that the end wall forms a completely closed end of the lid.

15. The method as claimed in claim 12, wherein the end wall of the lid to which the welding promoting element is permanently connecting includes an annular rib axially protruding from the end wall toward the interior space of the lid, the annular rib being positioned inwardly of the cylindrical lateral wall and surrounding a seat, the permanent connection of the welding promoting element to the end surface of the end wall of the lid comprising permanently connecting the welding promoting element to the end surface of the end wall so that the welding promoting element is located at the seat.

16. The closure as claimed in claim 12, further comprising an annular rib axially protruding from the end wall of the lid toward the interior space of the lid, the annular rib being positioned inwardly of the cylindrical lateral wall, the annular rib surrounding a seat at which is located the welding promoting element.

17. The method as claimed in claim 16, wherein the end wall of the lid to which the welding promoting element is permanently connecting is a non-apertured end wall so that the end wall forms a completely closed end of the lid.

Description

BRIEF DESCRIPTION OF DRAWING FIGURES

(1) A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

(2) FIG. 1 shows an axial section of an opening device according to the present invention, applied on a sectioned receiving portion of a sheet packaging material forming a container;

(3) FIG. 2 shows a larger-scale section of the FIG. 1 sheet packaging material before the opening device is applied thereto;

(4) FIG. 3 shows a smaller-scale, partly-sectioned, perspective view of the FIG. 1 opening device;

(5) FIG. 4 shows a smaller-scale perspective view of the FIG. 1 opening device in an open condition;

(6) FIG. 5 shows a smaller-scale perspective view of a closure of the FIG. 1 opening device during a step for producing the closure itself;

(7) FIG. 6 shows a larger-scale axial section of the FIG. 5 closure during another step for producing it;

(8) FIG. 7 shows a perspective view of the FIG. 5 closure after its production; and

(9) FIG. 8 is analogous to FIG. 1 and shows the container provided with the opening device during a final step of the method for producing the latter.

DETAILED DESCRIPTION

(10) Number 1 in FIGS. 1, 3, 4 and 8 indicates as a whole a reclosable opening device for a container 100, in particular a sealed container for packaging pourable food products.

(11) In the example shown in FIGS. 1 and 8, opening device 1 is applied to a receiving portion 2 of a multilayer sheet packaging material 3, in turn folded, filled with a pourable food product and sealed in a known manner to form container 100.

(12) With particular reference to FIG. 2, packaging material 3 comprises a base layer 4 for stiffness and strength, which may be made of fibrous material, e.g. paper, or mineral-filled polypropylene material, and a plurality of layers 5 of heat-sealable plastic material, e.g. polyethylene films, covering both sides of base layer 4.

(13) In the case of an aseptic container for long-storage products, such as UHT milk, packaging material 3 also comprises a layer 6 of gas-barrier material, e.g. aluminium foil or ethyl vinyl alcohol (EVOH) film, which is superimposed on a layer 5 of heat-sealable plastic material, and is in turn covered with another layer 5 of heat-sealable plastic material forming the inner face of the container eventually contacting the food product.

(14) In other words, layers 5 and 6 define respective lamination layers applied to base layer 4 when producing packaging material 3 in the form of a continuous strip.

(15) In the example shown, receiving portion 2 is defined by a so-called pre-laminated hole, i.e. a hole 9 formed through base layer 4 of packaging material 3 and covered by lamination layers 5, 6, so that hole 9 is sealed by a sheet cover portion 10.

(16) In a possible alternative embodiment not shown, cover portion 10 may even be defined by only one or some of layers 5, 6. For example, cover portion 10 may be made solely of gas-barrier material.

(17) In another possible alternative embodiment not shown, cover portion 10 may be defined by a patch fixed to the rest of packaging material 3 to seal a hole formed, in this case, through the full thickness of such packaging material 3.

(18) In a further alternative embodiment not shown, receiving portion 2 may be simply defined by a hole formed through the full thickness of the packaging material 3 and which is destined to be sealed by opening device 1.

(19) With reference to FIGS. 1, 3, 4 and 8, opening device 1 has an axis A, which in use is substantially perpendicular to receiving portion 2 of packaging material 3; opening device 1 basically comprises:

(20) a pouring spout 12 fixed to packaging material 3 at hole 9 and having a cylindrical tubular neck 13 of axis A, defining a pouring opening 14, by which to pour in use the content of the container; a closing element 15 closing or sealing pouring opening 14 and integrally connected to pouring spout 12 by a smaller-section, annular membrane 16 adapted to be easily torn in use; and a closure 18 fitted to neck 13 of pouring spout 12 in a removable manner to close or seal pouring opening 14 at a region thereof different from that closed by closing element 15.

(21) Annular membrane 16 defines a tear line along which to detach in use closing element 15 from pouring spout 12.

(22) According to a preferred embodiment of the present invention, pouring spout 12 and closing element 15 are formed in one piece on receiving portion 2 of packaging material 3, whilst closure 18 is formed separately from pouring spout 12 and closing element 15 and then fitted thereto.

(23) In the solution disclosed in the FIGS. 1 to 4 and 8, pouring spout 12 and closing element 15 are obtained by molding molten plastic materialin particular by an injection molding operationon the packaging material 3 before it is transformed in container 100.

(24) More specifically, the plastic material destined to form pouring spout 12 and closing element 15 is injected in a molten state onto one side 10ai.e. the side eventually facing inwards of the final containerof cover portion 10 placed in a known manner within a molding apparatus (known per se and not shown). In particular, the molten plastic material covers side 10a of cover portion 10 up to an annular peripheral region thereof so as to form, in this way, the closing element 15 directly attached to the cover portion 10; the molten plastic material is then forced to pierce cover portion 10 at such annular peripheral region to form pouring spout 12 projecting from an opposite side 10b of the cover portion 10 and attached to closing element 15 through smaller-section annular membrane 16, which is in turn adapted to be torn by the user to open the container.

(25) In this way, the material forming the pre-laminated hole is first pierced through and then resealed by the plastic material forming the pouring spout 12.

(26) In practice, neck 13 of pouring spout 12 extends through cover portion 10 as a follow-on from the piercing thereof so as to be arranged on both sides 10a, 10b of the cover portion 10 itself.

(27) Closing element 15 and cover portion 10 of hole 9 together define a sealing portion sealing pouring opening 14 of pouring spout 12. Closing element 15 substantially has a confetti shape.

(28) According to a possible alternative not shown, the plastic material destined to form pouring spout 12 and closing element 15 may be also directly injected in a molten state through a hole of the packaging material 3 so that such hole is then completely sealed by closing element 15 only.

(29) As shown particularly in FIGS. 1, 3, 4 and 8, pouring spout 12 further comprises an annular flange 20 fixed to packaging material 3 at the edge of hole 9; neck 13 projects axially and integrally from an annular region of flange 20 radially interposed between an outer edge 21 of the flange 20 itself and annular membrane 16.

(30) In practice, closing element 15 defines a prolongation of flange 20 inside pouring spout 12 and closes or seals one axial end 22 of the pouring spout 12; in a different manner, closure 18 seals the opposite axial end 23 of pouring spout 12, even after removal in use of closing element 15 and cover portion 10.

(31) Closing element 15 is advantageously formed in one piece with a protruding portion 24 extending through pouring opening 14 and welded to closure 18 far away from the closing element 15. In other words, protruding portion 24 is welded to closure 18 at a given, not null, axial distance from closing element 15.

(32) With reference to FIGS. 1 and 3 to 8, closure 18 basically comprises a lid 25 and a disk-shaped welding promoting element 26 to connect the lid 25 to protruding portion 24.

(33) In particular, lid 25 comprises a disk-shaped end wall 27, closing pouring opening 14 of pouring spout 12 at end 23 thereof, and a cylindrical lateral wall 28 cooperating with the outer surface of neck 13 of pouring spout 12.

(34) In the example shown, lid 25 is of a screw type and lateral wall 28 has an inner thread 29, which engages a corresponding outer thread 30 on neck 13 of pouring spout 12.

(35) Lid 25 further comprises integrally an annular rib 27a axially protruding from end wall 27 towards the inside of the lid 25 itself and defining a seat 27b for receiving welding promoting element 26.

(36) As visible in FIGS. 1, 3, 5, 6, 7 and 8, welding promoting element 26 is defined by a multilayer sheet element 31 distinct from lid 25 and permanently connected to the lid 25.

(37) In particular (FIG. 3), sheet element 31 comprises a layer 32 of conductive material, e.g. an aluminum foil, and at least two layers 33, 34 of heat-sealable plastic material, e.g. polyethylene films, covering both sides of layer 32 and defining respective opposite faces 35, 36.

(38) In the example shown, face 35 of sheet element 31 is configured to be welded to end wall 27 by the heat generated by inducing an electric current in layer 32; in an analogous manner, face 36 of sheet element 31 is configured to be welded to protruding portion 24 by the heat generated by inducing an electric current in layer 32.

(39) As shown in FIGS. 1, 3, 4 and 8, protruding portion 24 comprises an annular body 37, welded to face 36 of sheet element 31, and two legs 38 integrally connecting annular body 37 to closing element 15. In particular, legs 38 have first ends 39, integrally connected to respective diametrically opposite portions of annular body 37 with respect to axis A, and second ends 40 integrally connected to closing element 15.

(40) As a possible alternative not shown, legs 38 may be also not diametrically opposite one another.

(41) As a further possible alternative not shown, protruding portion 24 may comprise more than two legs 38 angularly spaced from each other.

(42) Opening device 1 is produced as follows.

(43) First of all, pouring spout 12 and closing element 15 are injection molded in one piece onto receiving portion 2 of packaging material 3.

(44) In particular, the packaging material 3 is placed with receiving portion 2 inside a molding apparatus; at this point, the molten plastic material is injected onto side 10a of cover portion 10 and flows along it up to the annular peripheral region thereof so as to form, in this way, the closing element 15 directly attached to the cover portion 10; the molten plastic material is then forced to pierce cover portion 10 at such annular peripheral region to form pouring spout 12 projecting from side 10b of the cover portion 10 and attached to closing element 15 through smaller-section annular membrane 16. In practice, the material forming cover portion 10 is first pierced through and then resealed by the plastic material forming the pouring spout 12.

(45) At this point, packaging material 3 is sterilized and then folded, filled with a pourable food product and sealed in a known manner to obtain container 100.

(46) Closure 18 is produced separately from pouring spout 12 and closing element 15 and then fitted thereto.

(47) In particular, after forming lid 25 and sheet element 31 in known manner, the latter is inserted into seat 27b of the lid 25 with face 35 in contact with end wall 27. The assembly so formed is then inserted between a pressure element 41 and an electric induction generating element 42 of an induction heating welding apparatus 43. More specifically, in the example shown in FIG. 6, the pressure element 41 also engages seat 27b of lid 25 and cooperates with face 36 of sheet element 31; electric induction generating element 42 comprises a coil 44 and cooperates with an external surface of end wall 27 of lid 25 opposite the surface of the end wall 27 itself cooperating with sheet element 31.

(48) By activating coil 44, an electric current is induced in layer 32 of conductive material of sheet element 31, with a consequent generation of localized heat producing the welding of the face 35 of heat-sealable plastic material to end wall 27 of lid 25.

(49) Closure 18 is then fitted to pouring spout 12 of container 100 with reciprocal engagement of threads 29 and 30.

(50) At this point, container 100 with opening device 1 cooperates with an electric induction generating element 46 (see FIG. 8). More specifically, electric induction generating element 46 is similar to electric induction generating element 42 and comprises a coil 48; electric induction generating element 46 cooperates with the external surface of end wall 27 of lid 25 opposite the surface of the end wall 27 itself cooperating with sheet element 31.

(51) By activating coil 48, an electric current is induced in layer 32 of conductive material of sheet element 31, with a consequent generation of localized heat producing the welding of the face 36 of heat-sealable plastic material to annular body 37 of protruding portion 24.

(52) This induction heating welding operation is performed at a distance, non null, along axis A from closing element 15 and, therefore, from adjacent packaging material 3, with no risk to damage it.

(53) According to a possible alternative not shown, closure 18 may be fitted to pouring spout 12 and welded to protruding portion 24 of closing element 15 by an induction heating welding operation carried out directly on the packaging material 3 in the form of a web, i.e. before such packaging material 3 is transformed in the finished container 100.

(54) In actual use, the first opening of the container is obtained by rotating lid 25 with respect to pouring spout 12 about axis A. At the beginning of the rotation impressed by the user on lid 25, legs 38 bend in the direction of rotation, so exerting a pulling action on closing element 15 at a given point of the annular membrane 16; in other words, due to the presence of the bending legs 38, the torque exerted on lid 25 is transformed in a pulling action on closing element 15, which starts to detach from pouring spout 12 at two given points along annular membrane 16.

(55) By continuing to rotate lid 25, it unscrews completely from pouring spout 12 together with closing element 15, which remains attached to the lid 25 (see FIG. 4) and therefore fully detaches along annular membrane 16 from the pouring spout 12 itself.

(56) The advantages of the opening device 1, the closure 18 and the methods for producing them according to the present invention will be clear from the foregoing description.

(57) In particular, thanks to the fact that closing element 15 is formed in one piece with protruding portion 24, in turn extending through pouring opening 14, the welding operation to connect the closing element 15 to lid 25 can be performed far away from the packaging material 3, without any risk to damage it. This also permits to have fewer constraints as to the parameters (temperature, power, pressure, etc.) used in the welding operation, with possible reduction of the time necessary to perform it.

(58) In addition, the use of a screw-type lid 25 in combination with a protruding portion 24, including two or more legs 38 connecting sheet element 31 to closing element 15, permits to transform the twisting action on the lid 25 in a pulling action on the closing element 15, with a strongly reduced effort for the user with respect to similar twisting known solutions. As a matter of fact, at the beginning of the rotation impressed by the user on lid 25, legs 38 bend in the direction of rotation, so producing a pulling action on closing element 15 at a given point of the annular membrane 16; this causes an initial detachment of the closing element 15 from the pouring spout 12 at two points of annular membrane 16 instead of requiring the same detachment along the entire annular membrane 16 simultaneously; the result is a reduced effort experienced by the user during the initial unsealing of closure 18 from pouring spout 12.

(59) Clearly, changes may be made to opening device 1, closure 18 and the methods for producing them as described herein without, however, departing from the scope of protection as defined in the accompanying Claims.