WO2001015979A1

WO2001015979A1 - Closable opening device for sealed packages of pourable food products

Info

Publication number: WO2001015979A1
Application number: PCT/EP2000/008197
Authority: WO
Inventors: Cristiano Casale
Original assignee: Tetra Laval Holdings & Finance Sa
Priority date: 1999-08-27
Filing date: 2000-08-22
Publication date: 2001-03-08
Also published as: AU7412000A; DE20014005U1; ITTO990726A1; IT1310146B1

Abstract

A closable opening device (2) having a frame (15), which defines a pour opening (16) and is fittable to a wall (6, 69) of a sealed package (1, 1') for pourable food products and about a removable portion (10a, 70a) of the package (1, 1'); a cap (17) cooperating with the frame (15) to close the pour opening (16); and tamperproofing means (32) connected to the cap (17) by breakable connecting means (34) and defining an inviolable closed position of the cap (17) on the frame (15); the tamperproofing means (32) having a connecting element (33) located outside and laterally with respect to the cap (17) and fixed to the frame (15).

Description

CLOSABLE OPENING DEVICE FOR SEALED PACKAGES OF POURABLE FOOD PRODUCTS

TECHNICAL FIELD The present invention relates to a closable opening device for sealed packages of pourable food products.

BACKGROUND ART

As is known, many pourable food products, such as fruit juice, UHT (ultra-high-temperature processed) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example of such a package is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark) , which is formed by folding and sealing a web of laminated packaging material . The packaging material has a multilayer structure comprising a layer of fibrous material, e.g. paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene, and, in the case of aseptic packages for long-storage products, such as UHT milk, also comprises . a layer of oxygen- barrier material defined, for example, by an aluminium film, which is superimposed on a layer of heat-seal plastic material and is in turn covered with another layer of heat-seal plastic material eventually defining the inner face of the package contacting the food product . As is known, such packages are made on fully automatic packaging machines, on which a continuous tube is formed from the web-fed packaging material; the web of packaging material is sterilized on the packaging machine itself, e.g. by applying a chemical sterilizing agent, such as a hydrogen peroxide solution, which, after sterilization, is removed, e.g. vaporized by heating, from the surfaces of the packaging material; and the web of packaging material so sterilized is maintained in a closed sterile environment, and is folded and sealed longitudinally to form a vertical tube.

The tube is filled with the sterilized or sterile- processed food product, and is sealed and cut at equally spaced cross sections to form pillow packs, which are then folded mechanically to form the finished, e.g. substantially parallelepiped-shaped, packages.

Alternatively, the packaging material may be cut into blanks, which are formed into packages on forming spindles, and the resulting packages are filled with the food product and sealed. One example of such a package is the so-called "gable-top" package commonly known by the trade name Tetra Rex (registered trademark) .

To open the package and protect the food product inside from contact with external agents, packages of the above type are normally provided with closable opening devices .

Opening devices of the so-called "screw" type, for example, substantially comprise an externally threaded frame defining an opening and fitted over a hole or a pierceable or removable portion in a wall of the package; and an internally threaded cap made separately from the frame and initially screwed to the frame to close the opening . More specifically, the frame comprises a base flange fitted to the package and internally defining the opening; and an externally threaded, cylindrical, annular portion projecting from a lateral edge of the opening, and to which a cylindrical lateral wall of the cap is screwed.

Once removed, the cap is movable between said closed position and an open position detached from the frame.

The cap is normally molded integral with a respective tamperproof ring connected coaxially to the cap by breakable radial connecting pieces.

The cap described is pressed onto the frame so that the tamperproof ring clicks onto the base flange and past the threaded portion of the frame close to the flange.

During assembly, the tamperproof ring must therefore overcome the underside recess defined by the thread on the annular portion of the frame - normally a difficult operation; and, on account of the tamperproof ring, the height of the opening device is normally considerable, thus increasing the overall size of the package. DISCLOSURE OF INVENTION

It is an object of the present invention to provide a closable opening device for sealed packages of pourable food products, designed to eliminate the aforementioned drawbacks typically associated with known opening devices .

According to the present invention, there is provided a closable opening device comprising a frame defining a pour opening and fittable to a wall of a sealed package for pourable food products and about a removable portion of the package; a cap cooperating with said frame to close said opening; and tamperproofing means connected to said cap by breakable connecting means and defining an inviolable closed position of said cap on said frame; characterized in that said tamperproofing means comprise a connecting element located outside and laterally with respect to said cap and fixed to said frame . The present invention also relates to a sealed package for pourable food products, having a closable opening device comprising a frame defining a pour opening and fitted to a wall of said package and about a removable portion of the package; a cap cooperating with said frame to close said opening; and tamperproofing means connected to said cap by breakable connecting means and defining an inviolable closed position of said cap on said frame; characterized in that said tamperproofing means comprise a connecting element located outside and laterally with respect to said cap and fixed to said frame .

BRIEF DESCRIPTION OF THE DRAWINGS Two preferred, non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a view in perspective of a sealed package for pourable food products, having a closable opening device in accordance with the present invention;

Figure 2 shows an enlarged section, indicating the component layers, of a portion of the Figure 1 package before the respective opening device is applied;

Figure 3 shows a larger-scale view in perspective of the Figure 1 opening device;

Figure 4 shows a larger-scale cross section of the Figure 1 opening device;

Figure 5 shows a schematic plan view of a heat-seal unit for applying the Figure 1 closable opening device to the respective package;

Figure 6 shows a larger-scale section, indicating the component layers, of a portion of a different embodiment of a sealed package for pourable food products designed to receive the Figure 1 opening device. BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole an aseptic sealed package for pourable food products, e.g. a parallelepiped-shaped package known as Tetra Brik Aseptic (registered trademark) , which is made from sheet packaging material as described in detail previously, and which comprises a closable opening device 2 (Figures 1, 3 and 4) made of plastic material and fitted to package 1 by means of a heat-seal unit 3 (Figure 5) .

The packaging material (Figure 2) from which package 1 is made has a multilayer structure, and comprises a main sheet 5 having a hole 7 in a top wall 6 of package 1, and defined by a layer of fibrous material 8, e.g. paper, covered with a film 9 of heat-seal plastic material - in the example shown, polyethylene - on the side defining the outer face of package 1.

On the side forming the inner face of package 1, main sheet 5 is covered with a laminated sheet 10 having a removable portion 10a covering hole 7.

Laminated sheet 10 comprises a film 12 of oxygen- barrier material, e.g. an aluminium film, which is covered, on the side facing the layer of fibrous material 8, with a film 11 of heat-seal plastic material, e.g. polyethylene, and, on the opposite side, with a layer of adhesive 13 and a further film 14 of heat-seal plastic material, normally polyethylene, defining the inner face of package 1.

With reference to Figures 1, 3 and 4, opening device 2 comprises an annular frame 15 fitted to wall 6 of package 1, about hole 7, and defining a circular opening

16 through which the food product is poured; and a cap 17 formed separately from frame 15 and fitted to frame 15 to close opening 16.

More specifically, frame 15 comprises an annular flange 20 heat sealed to wall 6 of package 1 and internally defining opening 16; and an externally threaded, cylindrical, annular portion 21 projecting from a lateral edge of opening 16.

More specifically, flange 20 is defined externally by a straight edge 22 and a curved U-shaped edge 23 connected to each other, and comprises, on an underside surface 24, a number of ribs 25 defining additional plastic material, which, when melted during heat sealing, adheres to the surface film 9 of main sheet 5 of wall 6 of package 1.

Cap 17 comprises, integrally, a portion 26 for closing opening 16; and an internally threaded, cylindrical, annular portion 27 projecting from a circular outer peripheral edge 26a of portion 26, and which screws onto annular portion 21 of frame 15.

More specifically, portion 26 defines a cavity 28 facing and flaring slightly away from the side fitted to frame 15, and comprises a circular bottom wall 29, and a truncated-cone-shaped lateral wall 30 tapering towards bottom wall 29 and defining, at the top, the peripheral edge 26a from which annular portion 27 extends in a radially outer and coaxial position with respect to lateral wall 30.

Annular portion 27 and truncated-cone-shaped lateral wall 30 together define a seat 31 for receiving annular portion 21 of frame 15, and which decreases in section towards peripheral edge 26a.

Cap 17 is initially fitted to frame 15 in an inviolable closed position, in which seat 31 is engaged in fluidtight manner by annular portion 21, by means of breakable tamperproofing means 32.

An important aspect of the present invention lies in tamperproofing means 32 comprising a block 33 of plastic material, which is connected externally to the side of cap 17 by two thin, low-break-strength strips 34, engages a through hole 35 formed in flange 20 of frame 15, and is heat sealed to the lateral edge of hole 35 and to surface film 9 of wall 6 of package 1.

More specifically, block 33 is substantially in the form of a triangular prism, and is connected integrally, by means of strips 34 and along one of its lateral edges, to a projection 36 projecting radially outwards from portion 27 of cap 17.

Initially, cap 17 is preferably pressed onto frame 15, after first aligning block 33 with hole 35 in frame 15, or may be screwed onto frame 15, so that block 33 is aligned with hole 35, and then pressed on.

Once unsealed, cap 17 is movable between said closed position, and an open position detached from frame 15. Cap 17 also comprises a cylindrical, annular anchoring portion 40, which extends from the peripheral edge of bottom wall 29, on the opposite side to lateral wall 30, projects through opening 16 in the closed position, and is fixed by heat-seal unit 3 directly to portion 10a of laminated sheet 10 covering hole 7 via the interposition of surface film 9 of heat-seal plastic material . More specifically, anchoring portion 40 is defined by two closely spaced, concentric, projecting annular edges 41.

Cap 17 also comprises, integrally, two radial tabs 42 substantially in the form of right trapeziums, and for screwing and unscrewing cap 17 easily on and off frame 15.

With reference to Figure 5, heat-seal unit 3 comprises a connecting head 43 for receiving one opening device 2 at a time at an input station 44, and which travels along a straight path P to transfer opening device to a heat-seal station 45, where opening device 2 is fitted to a respective package 1; a gripping assembly 46 for receiving one package 1 at a time, and which travels along a path Q, crosswise to path P, to feed package 1 into heat-seal station 45 and into contact with a respective opening device 2; and a first and second heating assembly 47, 48 interacting respectively with opening devices 2 and packages 1 along respective paths P and Q upstream from heat-seal station 45. More specifically, connecting head 43 is mounted to run along a straight guide 49 defining path P, and retains the cap 17 side of one opening device 2 at a time on a front face 50 by suction. Gripping assembly 46 comprises four plates 51 (only one shown in Figure 5) arranged in two parallel pairs to define a rectangular-section seat for receiving a respective package 1, which is positioned with top wall 6 projecting from plates 51 and facing guide 49 to receive a respective opening device 2.

Known actuating means (not shown) cause plates 51 to grip respective lateral walls 52 of package 1, so that, the food content of package 1 being incompressible, wall 6 swells into an outwardly convex configuration to simplify application of opening device 2.

Assembly 47 comprises an air heating member 53, which is moved along guide 49, by known actuating means

(not shown) , between a work position facing wall 6 of package 1 gripped between plates 51 of gripping assembly

46 to blow hot air onto the portion of wall 6 for receiving respective opening device 2, and a rest position withdrawn from package 1 to enable connecting head 43 to be fed into heat-seal station 45. Assembly 48 comprises an air preheating element 54 and a microflame burner 55 in series with each other and facing guide 49 along path P between input station 44 and heat-seal station 45. More specifically, burner 55 is defined by a heating plate shaped to reproduce the outer contour of frame 15 of opening device 2, and having a number of holes (not shown in Figure 5) through which hydrogen is emitted.

Operation of unit 3 will be described with reference to one package 1 and one opening device 2, and as of an initial condition in which package 1 is gripped between plates 51 of gripping assembly 46, and opening device 2 is retained by suction on front face 50 of connecting head 43 at input station 44.

Connecting head 43 is moved along path P to position opening device 2 facing preheating element 54, where it remains for a predetermined time Tl, preferably of 0.4 of a second, and where it is subjected to a hot-air jet conveniently at a temperature of 450°C.

At the end of the above operation, connecting head 43 is moved along path P to position opening device 2 facing burner 55, where it remains for a predetermined time T2 of, in the example, 0.3 of a second. At the same time, heating member 53, in the work position, is activated to direct a hot-air jet conveniently at a temperature of 500°C - onto the portion of wall 6 of package 1 for receiving opening device 2. This operation lasts a predetermined time T3 , at most equal to the time taken by connecting head 43 to move from input station 44 to heat-seal station 45, and, in the example shown, equal to 0.8 of a second.

On being returned to the rest position, heating member 53 is replaced by connecting head 43 moving into heat-seal station 45. At this point, gripping assembly 46 is moved along path Q to bring wall 6 of package 1 into contact with opening 2, and to keep wall 6 pressed against opening device 2 for the time T4 necessary to achieve adhesion - 1 second in the example shown - and under a pressure preferably ranging between 3.5 and 3.9 N.

At this stage, the partly melted plastic material of frame 15 and anchoring portion 40 of cap 17 adheres respectively to surface film 9 of main sheet 5 about hole 7, and, via the interposition of film 9, to portion 10a of laminated sheet 10 covering hole 7. At the same time, block 33 is sealed along the edges of hole 35 in flange 20 of frame 15 and to surface film 9 of main sheet 5 of wall 6 of package 1.

In actual use, package 1 is unsealed using tabs 42 to turn cap 17 with respect to frame 15 and break strips 34 connecting block 33 to cap 17. As it turns, cap 17 retains portion 10a of laminated sheet 10 covering hole 7 and sealed to anchoring portion 40, so as to remove portion 10a from the rest of wall 6 and uncover hole 7.

Alternatively, opening device 2 may advantageously be applied by heat-seal unit 3 to packages other than the type described above, e.g. to nonaseptic packages for pourable food products such as pasteurized milk, an example of which is shown partly and schematically in Figure 6 and indicated as a whole by 1 ' .

The material from which package 1 ' is made has a multilayer structure, and comprises a layer 70 of fibrous material, e.g. paper, covered on both sides with respective films 71, 72 of heat-seal plastic material, e.g. polyethylene, and having, on a wall 69 of package 1', a removable portion 70a defined by a preferential tear line 73 in turn defined by a succession of perforations .

In this case, frame 15 of opening device 2 is sealed about removable portion 70a of package 1', and anchoring portion 40 of cap 17 is sealed directly to removable portion 70a via the interposition of film 71 of heat-seal plastic material.

The advantages of packages 1, 1' and opening device 2 according to the present invention will be clear from the foregoing description.

In particular, by virtue of tamperproofing means 32 extending laterally and externally with respect to tap 17 and within the overall axial dimension of the cap, the total height of opening device 2 is particularly small and exclusively equal to the height of cap 17 itself.

Moreover, opening device 2 is easier to assemble, by no underside recesses having to be overcome when fitting cap

17 to frame 15. Clearly, changes may be made to packages 1, 1' and opening device 2 without, however, departing from the scope of the accompanying Claims .

In particular, opening device 2 may be fixed otherwise, e.g. by means of adhesive substances, to packages 1, 1 ' .

Claims

1) A closable opening device (2) comprising a frame

(15) defining a pour opening (16) and fittable to a wall (6, 69) of a sealed package (1, 1') for pourable food products and about a removable portion (10a, 70a) of the package (1, 1'); a cap (17) cooperating with said frame

(17) to close said opening (16) ; and tamperproofing means

(32) connected to said cap (17) by breakable connecting means (34) and defining an inviolable closed position of said cap (17) on said frame (15) ; characterized in that said tamperproofing means (32) comprise a connecting element (33) located outside and laterally with respect to said cap (17) and fixed to said frame (15) . 2) A device as claimed in Claim 1, characterized in that said connecting element (33) is fittable to said package (1, 1') through a through hole (35) in said frame (15) .

3) A device as claimed in Claim 2, characterized in that said connecting element (33) is heat sealed to said frame (15) and to said wall (6, 69) of said package (1,

1') •

4) A device as claimed in any one of the foregoing Claims, characterized in that said connecting element (33) projects integrally from a lateral portion (27) of said cap (17) .

5) A device as claimed in any one of Claims 2 to 4 , characterized in that said frame (15) comprises a base flange (20), which is fittable to said wall (6, 69) of said package (1, 1'), internally defines said opening (16) , and has said hole (35) for said connecting element

(33) . 6) A device as claimed in Claim 5, characterized in that said frame (15) comprises an externally threaded, cylindrical annular portion (21) projecting from said base flange (20) from a lateral edge of said opening (16) ; and in that said lateral portion (27) of said cap (17) is cylindrical, is threaded internally, and screws onto said annular portion (21) of said frame (15) .

7) A device as claimed in Claim 6, characterized in that said connecting element is defined by a block (33) of plastic material projecting radially from said lateral portion (27) of said cap (17) .

8) A device as claimed in Claim 6 or 7, characterized in that said cap (17) comprises at least one pair of tabs (42) extending radially outwards from said lateral portion (27) of the cap. 9) A sealed package (1, 1') for pourable food products, having a closable opening device (2, 2') comprising a frame (15) defining a pour opening (16) and fitted to a wall (6, 69) of said package (1, 1') and about a removable portion (10a, 70a) of the package (1, 1'); a cap (17) cooperating with said frame (15) to close said opening (16) ; and tamperproofing means (32) connected to said cap (17) by breakable connecting means

(34) and defining an inviolable closed position of said cap (17) on said frame (15) ; characterized in that said tamperproofing means (32) comprise a connecting element (33) located outside and laterally with respect to said cap (17) and fixed to said frame (15) . 10) A package as claimed in Claim 9, characterized in that said connecting element (33) is fixed to said wall (6, 69) through a through hole (35) in said frame (15) .

11) A package as claimed in Claim 10, characterized in that said connecting element (33) is heat sealed to said frame (15) and to said wall (6, 69) .

12) A package as claimed in any one of Claims 9 to

11, characterized in that said connecting element (33) projects integrally from a lateral portion (27) of said cap (17) .

13) A package as claimed in any one of Claims 10 to

12, characterized in that said frame (15) comprises a base flange (20), which is fitted to said wall (6, 69), internally defines said opening (16) , and has said hole (35) for said connecting element (33) .

14) A package as claimed in Claim 13, characterized in that said frame (15) comprises an externally threaded, cylindrical annular portion (21) projecting from said base flange (20) from a lateral edge of said opening (16) ; and in that said lateral portion (27) of said cap (17) is cylindrical, is threaded internally, and screws onto said annular portion (21) of said frame (15) .

15) A package as claimed in Claim 14, characterized in that said connecting element is defined by a block (33) of plastic material projecting radially from said lateral portion (27) of said cap (17) .

16) A package as claimed in Claim 14 or 15, characterized in that said cap (17) comprises at least one pair of tabs (42) extending radially outwards from said lateral portion (27) of the cap.

17) A package as claimed in any one of Claims 9 to

16, characterized in that said cap (17) comprises an anchoring portion (40) fixed directly to said removable portion (10a, 70a) of said wall (6, 69) in said inviolable closed position of the cap (17) .

18) A package as claimed in any one of Claims 9 to

17, characterized in that said removable portion (10a) of said wall (6) comprises at least one film of oxygen- barrier material (11) .

19) A package as claimed in Claim 18, characterized by being made of a packaging material having a multilayer structure and comprising at least one layer of fibrous material (8) having a through hole (7) and covered at least on one side with a laminated sheet (10) including said film of barrier material (11) , covering said hole

(7) , and defining, at said hole (7) , said removable portion (10a) of said wall (6) . 20) A package as claimed in any one of Claims 9 to 17, characterized in that said wall (69) comprises at least one layer of fibrous material (70) ; and in that said removable portion (70a) of said wall (69) is defined O

by a portion of said layer of fibrous material (70) defined by a preferential tear line (73) .