CONTAINER SEALING APPARATUS AND METHOD OF SEALING

Abstract

There is provided container sealing apparatuses and methods for sealing openings of containers with film. The apparatuses comprise: a pressing member configured to press a film into contact with a container; and a sealing beam source configured to emit one or more sealing beams, each of said sealing beams being incident on the container and/or the film, each of said sealing beams being incident local to a respective part of the pressing member which engages the container so as to join the film to the container; the container sealing apparatus being configured to move the container relative to the pressing member, such that a region of the container which is engaged by the pressing member changes.

Claims

1. A container sealing apparatus for sealing openings of containers with film, the container sealing apparatus comprising: a pressing member configured to press a film into contact with a container; and a sealing beam source configured to emit one or more sealing beams, each of said sealing beams being incident on the container and/or the film, each of said sealing beams being incident local to a respective part of the pressing member which engages the container so as to join the film to the container; the container sealing apparatus being configured to move the container relative to the pressing member, such that a region of the container which is engaged by the pressing member changes.

2. A container sealing apparatus according to claim 1, wherein the sealing beam source is configured to control the position of a sealing beam of the one or more sealing beams relative to the container and/or the pressing member.

3. A container sealing apparatus according to claim 1, the sealing beam source being configured to join the film to the container along a path of relative movement between the container and a sealing beam of the one or more sealing beams.

4. A container sealing apparatus according to claim 1, further comprising a transport system for transporting containers.

5. A container sealing apparatus according to claim 4, wherein the transport system is configured to transport containers with a consistent spacing and/or with a consistent orientation.

6. A container sealing apparatus according to claim 1, further comprising a sensor configured to determine the position and orientation of the container relative to the pressing member, and wherein the sealing beam source is configured to control the position of a sealing beam of the one or more sealing beams based on the determined position and orientation of the container.

7. A container sealing apparatus according to claim 1, wherein the pressing member extends in a first direction, and wherein the sealing beam source is configured to change the position of a sealing beam of the one or more sealing beams relative to the pressing member along a second direction parallel to the first direction.

8. A container sealing apparatus according to claim 7, wherein the first direction in which the pressing member extends is angled with respect to the direction in which the container moves relative to the pressing member.

9. A container sealing apparatus according to claim 8, wherein the angle between the first direction in which the pressing member extends and the direction in which the container moves relative to the pressing member is in the range of 15 to 75 degrees, and preferably is in the range of 30 to 60 degrees, and more preferably is approximately 45 degrees.

10. A container sealing apparatus according to claim 7, wherein the width of the pressing member perpendicular to the direction in which the container moves relative to the pressing member is greater than the width of the container perpendicular to the direction in which the container moves relative to the pressing member.

11. A container sealing apparatus according to claim 7, wherein the sealing beam source is configured to emit a first sealing beam and a second sealing beam, and to control the position of the first sealing beam and second sealing beam such that the first sealing beam and second sealing beam move in opposing directions around the perimeter of an opening of the container.

12. (canceled)

13. (canceled)

14. A container sealing apparatus according to claim 1, wherein the container sealing apparatus further comprises a pressing member control system configured to move the pressing member, such that the pressing member may be moved relative to the container.

15. A container sealing apparatus according to claim 14, wherein the sealing beam source is configured to control the position of a sealing beam such that the sealing beam moves with the pressing member relative to the container.

16. A container sealing apparatus according to claim 14, wherein the pressing member is annular, and the sealing beam source is configured to control the sealing beam such that the sealing beam passes through the central hole of the annular pressing member.

17. (canceled)

18. A container sealing apparatus according to claim 1, further comprising a cutting system configured to separate sealed containers from the surrounding film.

19. (canceled)

20. (canceled)

21. A container sealing apparatus according to claim 1, wherein the sealing beam source is configured to emit one or more sealing beams which are incident on the container and/or the film within 2 cm of the pressing member, preferably within 1 cm of the pressing member.

22. A container sealing apparatus according to claim 1, wherein the pressing member comprises a flexible and resilient material.

23. A container sealing apparatus according to claim 1, wherein a surface of the pressing member configured to engage the container is angled towards the path of the container along the direction of relative movement between the container and the pressing member.

24. A container sealing apparatus comprising a plurality of sealing systems, each sealing system comprising: a pressing member configured to press a film into contact with a container; and a sealing beam source configured to emit one or more sealing beams, each of said sealing beams being incident on the container and/or the film, the sealing beam being incident local to a respective part of the pressing member which engages the container so as to join the film to the container; wherein the container sealing apparatus is configured to move a line of containers relative to the pressing members and to alternately operate the plurality of sealing systems to seal consecutive containers along the line of containers.

25. A method for sealing openings of containers with film, the method comprising: pressing film into contact with a container using a pressing member; operating a sealing beam source to emit one or more sealing beams, each of said sealing beams being incident on the container and/or the film, the sealing beam being incident local to a respective first part of the pressing member which engages the container so as to join the film to the container; and, moving the container relative to the pressing member, such that a region of the container that is engaged by the pressing member changes; and operating the sealing beam source to emit one or more sealing beams, each of said sealing beams being incident on the container and/or the film, the sealing beam being incident local to a respective second part of the pressing member which engages the container so as to join the film to the container.

26. (canceled)

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Description

BRIEF DESCRIPTION OF DRAWINGS

[0143] FIGS. 1a, 1b and 1c show a cross section, plan view and projection view of a tray which may be sealed using apparatuses and methods according to embodiments of the invention.

[0144] FIG. 2 shows a schematic elevation view of a container sealing apparatus according to an embodiment of the invention.

[0145] FIGS. 3a to 3g respectively show sequential schematic plan views of a container sealing apparatus according to embodiments of the invention.

[0146] FIG. 4 shows a schematic plan view of a container sealing apparatus according to embodiments of the invention.

[0147] FIG. 5 shows a schematic plan view of a container sealing apparatus according to embodiments of the invention.

[0148] FIGS. 6a and 6b show examples of pressing members suitable for use in embodiments of the invention.

[0149] FIGS. 7a and 7b respectively show schematic elevation and plan views of a container sealing apparatus according to embodiments of the invention.

DETAILED DESCRIPTION

[0150] FIG. 2 shows schematically a container sealing apparatus 100 in cross section during the sealing of containers 10. These containers 10 comprise an upwardly facing opening 14 (such that the containers 10 are trays) surrounded by a rim 12.

[0151] The container sealing apparatus 100 comprises a pressing member 30, a sealing beam source 40 and a transport system 50. As shown, the transport system 50 (e.g. a conveyor) transports containers 10 in a direction D past the pressing member 30 and the sealing beam source 40. The pressing member 30 is positioned over the transport system 50 such that containers 10 travel or pass between the pressing member 30 and the transport system 50.

[0152] As shown, the container sealing apparatus 100 receives a web of film 20 which moves through the apparatus in direction d. The film 20 passes between the pressing member 30 and the containers 10.

[0153] As a container 10 and the film 20 pass between the pressing member 30 and the transport system 50, the pressing member 30 pushes the film 20 into contact with a container 10 (e.g. such that the pressing member 30 is in contact with the film 50, and the film 50 is in contact with the container 10 along a single line).

[0154] The sealing beam source 40 is arranged downstream of the pressing member 30 in direction D. To join the film 50 to the container 10, the sealing beam source 40 emits at least one sealing beam 42 suitable for joining a film 20 to the containers 10. The sealing beam(s) 42 are incident on the container 10 and/or the film 50 local to the pressing member 50 where the film 50 is in contact with the container 10. Consequently, the sealing beam(s) 42 join the film 50 to the container 10. For instance, the sealing beam(s) 42 may activate an adhesive present on the surface of the film 20 or the container 10, and/or melt the container 10 and/or the film 20 such that they are fused together.

[0155] The pressing member 30 may be formed of a flexible and resilient material such as rubber. As such, in use the pressing member 30 may be deformed into a curved shape, as shown in FIG. 2. As a resilient material, the pressing member 30 will is biased to return to its original shape, and therefore will continue to press film 20 into contact with the container 10 regardless of minor changes in the position of the rim 12 (e.g. as may be caused by imperfections in the surface of the container 10 or changes in the position of the transport system 50 on which the container 10 is supported). This helps ensure an effective join between the film 20 and container 10 regardless of changes in the position or shape of the container 10.

[0156] The surface 30a of the pressing member 30 which contacts the film 20 is angled towards the containers 10 (i.e. towards the path of the containers) in the direction of relative movement between the containers 10 and the pressing member 30 (i.e. along direction D). Specifically, a leading or upstream edge 30a of the pressing member 30 is positioned at a greater distance from the transport system 50 and the feed path of the containers 10 than the trailing or downstream edge of the pressing member 30. Consequently, the pressing member 30 accurately engages the film 20 and the containers 10, regardless in variations in the feeding of film 20 or the positioning of the film 20 and the containers 10. Again, this contributes to an effective seal around the opening of the containers 10, which avoids spills and prevents spoilage of packaged foods.

[0157] In the specific example shown in FIG. 2, the at least one sealing beam 42 passes adjacent to the pressing member 30, close to the trailing edge 30b of the pressing member 30 (i.e. the edge of the pressing member 30 further downstream in the direction of movement of containers 10 relative to the pressing member 30). This application of sealing beam(s) 42 local to the part of the pressing member 30 which engages the film 20 and the container 10 ensures an effective join since the film 20 remains in contact with or close to the surface of the container 10 where the sealing beam(s) 42 are incident.

[0158] In other embodiments, sealing beam(s) may be applied at other locations (e.g. upstream of the pressing member 30 in direction D). Alternatively, the pressing member may be configured to be transparent to the sealing beam(s) such that the sealing beam(s) may be transmitted through the pressing member 30 and be incident on the film 20 and/or container 10 whilst the pressing member 30 is in contact with the film 20.

[0159] As shown, the sealing beam source 40 is provided above the transport system 50 (i.e. such that the sealing beam source 40 is on the same side of the transport system as the pressing member 30 and the containers 10). However, in other embodiments a sealing beam source may alternatively or additionally be provided on the opposing side of the transport system 50 to the pressing member 30 (i.e. underneath the transport system 50 shown in FIG. 2). In such examples one or more sealing beams may be transmitted from the sealing beam source 40 through the transport system 50 before being incident on the film 20 and/or container 10. For instance, the sealing beam(s) may pass through an aperture in the transport system 50 or a portion of the transport system 50 which is transparent to the sealing beam(s).

[0160] The transport system 50 shown in FIG. 2 may be operated to transport the containers 10 continuously or discontinuously relative to the pressing member 30 and the sealing beam source 40. As the containers 10 move relative to the pressing member 30 the portion of the container 10 which is engaged by the pressing member 30 and the part of the container 10 and/or film at which the sealing beam 42 is incident changes. In other words, different, laterally spaced portions of the container 10 and film are engaged by the pressing member 30 as the container 10 is moved relative to the pressing member 30. Thus different parts of the container 10 may be joined to the film as may be necessary to seal around an opening in the container 10.

[0161] The speed of a transport system 50 may be determined, for instance, depending on the dwell time required to achieve a suitable join between the film 20 and the container 10. However, preferably the web of film 20 is fed to the container sealing apparatus 100 at a speed that is equal to the rate at which containers 10 are transported by the transport system 50 to avoid the web becoming slack or excessively taut. This helps avoid misfeeds, and acts to ensure an effective join between the container 10 and the film 20. In other embodiments each container 10 or a batch of containers 10 may be sealed with a single sheet of film (i.e. in a sheet-fed rather than web-fed process).

[0162] As shown in FIG. 2, the transport system 50 supplies containers 10 at consistent intervals (i.e. with a constant period between consecutive containers) and at a consistent orientation (e.g. such that each container transported by the transport system 50 is aligned with the remaining containers and preferably with the direction of movement). Such a regular and predictable transport of containers simplifies control of the sealing beam(s) 42 since the sealing beams(s) 42 may be operated in a consistent manner for each container. However, these features are not essential.

[0163] In further embodiments the system may comprise a sensor, such as a camera, configured to determine the position and orientation of containers as they move relative to the pressing member, and may be configured to control the sealing beam 42 based on the determined position and orientation of each container so as to accurately join the film to said container.

[0164] To fully seal around opening 14 the sealing beam(s) 42 may be operated to join the film 20 to the container 10 around the entire perimeter of the opening 14 (i.e. such that a join surrounds the opening 14). This may produce a gastight and watertight seal across the opening 14. An example of such a process and methods of operating a sealing beam source will now be discussed with reference to FIGS. 3a to 3g, in which corresponding features are provided with similar reference signs.

[0165] The method and apparatus which will be described below with reference to FIGS. 3a and 3g provides a simple and efficient means of sealing a container 10 (or other container) whilst the container 10 moves relative to a pressing member 30. In particular, sealing containers whilst they are continuously moving enables high throughputs as interruptions in the flow of containers 10 may be avoided.

[0166] FIGS. 3a to 3g show sequential images of a container sealing apparatus 110 in plan view as a container 10 (e.g. a tray) moves relative to a pressing member 30 in direction D. The container 10 is sealed by a film (not shown in these figures for ease of understanding).

[0167] The relative motion between the container 10 and the pressing member 30 may be achieved using a transport system configured to move the containers 10 (such as in FIG. 2), and/or a system configured to move the pressing member 30. As mentioned above, the relative movement is preferably continuous, and the speed of the relative movement is preferably equal to a feed rate of a web or sheet of film (not shown) used to seal the container 10.

[0168] As shown in FIG. 3a (where a container 10 and a film (not shown) approach the pressing member 30), the container 10 is substantially rectangular and comprises an opening 14 to an internal volume within which a product may be contained, the opening 14 being surrounded by a rim 12. To simplify control of a sealing beam source, the container 10 is orientated such that its long axis is parallel to the direction D of relative movement between the container 10 and the pressing member 30, and its short axis is perpendicular to this direction D of relative movement.

[0169] The pressing member 30 extends in a first direction P which is angled with respect to the direction D in which the container 10 moves relative to the pressing member 30 (i.e. such that the pressing member 30 extends in a direction is not substantially parallel or perpendicular to the path of the container relative to the pressing member 30). Specifically, the pressing member in FIGS. 3a to 3g is orientated at 45 degrees relative to the direction D in which the container 10 moves relative to the pressing member 30. The pressing member 30 is wider than the container 10 and may contact the rim 14 across the full width of the container 10.

[0170] The container sealing apparatus 110 further comprises a sealing beam source (not shown). The sealing beam source is configured to emit two sealing beams 42a, 42b. The sealing beam source is configured to control the position or path of each sealing beam 42a, 42b such that the position of each sealing beam 42a, 42b may be varied along a scan line 44 which extends parallel to the direction P in which the pressing member 30 extends. Consequently, the sealing beams 42a, 42b may be applied along a scan line 44 which is angled with respect to direction D of relative movement between the container 10 and the pressing member 30. The scan line 44 along which the sealing beams 42a, 42b may be moved is adjacent (i.e. local) to the pressing member 30.

[0171] As the container 10 travels relative to the pressing member 30 a film (not shown) positioned between the pressing member 30 and the container 10 will be pressed into contact with the container 10. Therefore, the sealing beams 42a, 42b may be applied to the film and/or the container 10 whilst they remain in contact, and before the film and container 10 have had an opportunity to move apart significantly. This ensures a successful join between the film and the container 10.

[0172] The sealing beam source is configured to control the two sealing beams 42a, 42b such that they travel in opposing directions around the perimeter of the opening 14 to the container 10. Furthermore, the sealing beam source is operated such that each sealing beam 42a, 42b moves relative to the container 10 the film will be joined to the container along each path of relative movement.

[0173] As shown, the sealing beam source controls the first sealing beam 42a to travel clockwise around the perimeter of the opening 14 and the second sealing beam 42b to travel anti-clockwise around the perimeter of the opening 14.

[0174] In these figures the movement of each sealing beam 42a, 42b is shown by two pairs of arrows. The first set of arrows represents the movement of the sealing beams 42a, 42b relative to the container (arrows a and b). Consequently, the first set of arrows a, b define the joins 46a, 46b formed between the film and the container by the first and second sealing beams 42a, 42b. The second set of arrows represents the movement of the sealing beams 42a, 42b along the scan line 44 and relative to the pressing member and sealing beam source (arrows α and β). Therefore, the second set of arrows α, β show the changes in position of the sealing beams 42a, 42b defined by the sealing beam source.

[0175] At FIG. 3b the container 10 and the film begin to pass the pressing member 30. The pressing member contacts the film, pressing the film into contact with container 10. The sealing beam source is operated to apply two sealing beams 42a, 42b at a corner of the rim 12 local or adjacent to the pressing member 30, thereby joining the film to the container 10.

[0176] As the container 10 continues to pass relative to the pressing member 30, the sealing beam source controls the positions of the first and second sealing beams 42a, 42b relative to the container 10 such that the first sealing beam 42a travels clockwise around the perimeter of the opening 14 and the second sealing beam 42b travels anti-clockwise around the perimeter of the opening 14. The sealing beams 42a, 42b meet at the corner of the container opposing the corner at which they started (as shown in FIG. 3f).

[0177] Consequently a continuous join is formed between the film and the container 10 around the entire rim 12 of the container 10. This join surrounds the opening 14 preventing liquids and gases from entering or leaving the container 10.

[0178] It will be appreciated that the sealing beams 42a, 42b may travel parallel to the direction D (i.e. the direction of relative motion between the container 10 and the pressing member 30) where the sealing beam source holds the position of the first sealing beam 42a constant. For instance, this may be seen between FIGS. 3b and 3c, and FIGS. 3c and 3d for the first sealing beam 42a, and between FIGS. 3d and 3e and FIGS. 3e and 3f for the second sealing beam 42b.

[0179] In these cases the sealing beams 42a, 42b do not move relative to the pressing member 30 and scan line 44. However, there remains relative movement between the container 10, and the pressing member 30 and sealing beam source in direction D. Thus the sealing beams 42a, 42b move parallel to this direction D relative to the container 10.

[0180] Equally, the sealing beams 42a, 42b may be controlled by the sealing beam source to move perpendicular to the direction of movement D relative to the container 10. Such motion can be seen between FIGS. 3b and 3c for the second sealing beam 42b and between FIGS. 3e and 3f for the first sealing beam 42a.

[0181] This movement is achieved where the sealing beam source moves the sealing beam along scan line 44 at a speed where the component of speed in direction D is equal the speed that the container 10 moves relative to the pressing member in direction D.

[0182] The movement of the sealing beams 42a, 42b relative to the container 10 around the corners of the container 10 may be achieved by varying the speed of at which the sealing beams 42a, 42b are moved along scan line 44 in comparison to the speed of the container 10 relative to the pressing member in direction D.

[0183] The sealing beam source may be configured to vary the power of the sealing beams 42a, 42b as the container 10 passes the scan line 44 to maintain a consistent join. This is because the dwell time of the sealing beams 42a, 42b on any portion of the rim will be determined by the speed at which containers 10 are conveyed past the scan line 44 and the angle of the traverse path of the sealing beams 42a, 42b (i.e. in this case the angle of rim 12) relative to the scan line 44. The sealing beam source may be configured to increase the power of the sealing beams 42a, 42b at the corners of the rim 12 to maintain consistent energy per unit area around the perimeter of the opening 14.

[0184] The throughput of containers through a packaging system containing a container sealing member as discussed above may be further increased by reducing the distance between the containers as they pass relative to the pressing member. Therefore, the rate at which containers are (for instance) transported by a transport system or engaged by the pressing member is increased.

[0185] However, when containers travel past the pressing member close to or adjacent to each other, multiple containers may be contacted by the pressing member simultaneously. This is especially likely where the pressing member is angled with respect to the direction in which a scan line of containers travel relative to a pressing member.

[0186] An example of this situation is shown in FIG. 4, which shows a container sealing apparatus 120 which is similar to the apparatus 110 discussed with reference to FIGS. 3a to 3g. Two containers 10a, 10b—which each comprise an opening 14a, 14b surrounded by a rim 12a, 12b—move sequentially in a scan line along a direction D relative to the pressing member 30 of a container sealing apparatus 120. The containers 10a, 10b are located substantially adjacent to one another such that the gap between them is small.

[0187] The containers 10a, 10b are aligned and orientated in the same direction to simplify the control of the sealing beams 42a, 42b, 42c, 42d. However, this is not essential.

[0188] As in FIGS. 3a to 3g, the pressing member 30 extends in a direction P which is angled with respect to the direction D of relative movement. Consequently, the containers 10a, 10b are each engaged by the pressing member 30 when the pressing member extends across the rear of the first container 10a and the front of the second container 10b.

[0189] A film is provided between the containers 10a, 10b, such that the pressing member 30 contacts the film and presses the film into contact with the rims 12a, 12b of each container 12a, 12b.

[0190] The container sealing apparatus 120 of FIG. 4 further comprises a sealing beam source configured to simultaneously emit four sealing beams 42a, 42b, 42c, 42d local to the pressing member 30. The sealing beam source is again configured to control the position of these sealing beams 42a, 42b, 42c, 42d along a scan line 44 which extends parallel to the direction P in which the pressing member 30 extends.

[0191] Initially, the sealing beam source is configured to emit a first sealing beam 42a and a second sealing beam 42b which may be made incident on first container 10a local to parts of the pressing member 30 which contacts the first container 10a. As the first container 10a moves past the pressing member 30, the sealing beams 42a, 42b may be controlled to move in opposing directions around the perimeter of the opening 14a of the first container 10a, thereby joining or connecting the film to the rim 12a of the first container 10 along the path of relative movement and sealing the opening 14a. This is analogous to the control the first and second sealing beams 42a, 42b discussed with reference to FIGS. 3a to 3g.

[0192] As the containers 10a, 10b continue to move relative to the pressing member 30 both the first and second containers 10a, 10b will be contacted by the pressing member 30 simultaneously and will each underlie the scan line 44 of the sealing beam source.

[0193] Therefore, the sealing beam source is further configured to emit a third sealing beam 42c and a fourth sealing beam 42d which are made incident on the rim 12b of the second container 10b. The third and fourth sealing beams 42c, 42d may be controlled to move in opposing directions around the perimeter of the opening 14b of the second container 10b to join or connect the film to the rim 14b of the second container 10b. Again this method of sealing the opening of the second container 10b is analogous to the control of the sealing beams discussed with reference to FIGS. 3a to 3g.

[0194] In other words, the sealing beam source is configured to emit sealing beams 42a, 42b, 42c, 42d incident on the containers 10a, 10b and/or the film overlying the containers 10a, 10b which are local to each point at which the pressing member 30 engages a container 10a, 10b. Therefore, the openings 14a, 14b of each container are sealed in a single pass of the containers 10a, 10b relative to the pressing member 30 and there is no requirement to perform subsequent sealing steps.

[0195] Therefore, the container sealing apparatus 120 which emits four sealing beams 42a, 42b, 42c, 42d is capable of efficiently sealing containers which are positioned close to each other as they are continuously transported relative to an angled pressing member 30.

[0196] Furthermore, the container sealing apparatuses 100, 110, 120 discussed above may also be modified to seal containers with multiple openings whilst the containers move continuously (i.e. during an in-line process).

[0197] FIG. 5 shows a container sealing apparatus 130 capable of efficiently sealing containers 80 with two openings 84a, 84b separated by a dividing portion 85. The dividing portion 58 formed continuously with the outer rim 82 of the containers 80.

[0198] This container sealing apparatus 130 comprises a pressing member 30. The container 80 travels (preferably continuously) in a direction D relative to the pressing member 30. The pressing member 30 extends in a direction P which is angled relative to the direction D of relative movement (e.g. at an angle of 45 degrees). As the container 80 moves relative to the pressing member 30, the pressing member 30 contacts a film (not shown), pressing the film into contact with the rim 82 and dividing portion 85 of the container 80.

[0199] The container sealing apparatus 130 further comprises a sealing beam source 40 (not shown) configured to emit three sealing beams 42a, 42b, 42e along a scan line 44 which is parallel to direction P and local to the pressing member 30, such that the film is joined to the container 80.

[0200] As the container 80 moves relative to the pressing member 30, the sealing beam source 40 controls the position of the sealing beams 42a, 42b, 42e along the scan line 44. Consequently, the film pressed into contact with the container 80 is joined to the container 80 along the path of relative movement between the sealing beams 42a, 42b, 42e and the container 80.

[0201] Specifically, as in FIGS. 3a, to 3g, the sealing beam source is configured to control the first and second sealing beams 42a, 42b such that, relative to the container 100, they travel in opposing directions around the outer rim 82. The first sealing beam 42a travels clockwise around the perimeters of the first and second openings 84a, 84b. Whereas, the second sealing beam 42b travels anticlockwise around the perimeters of the first and second openings 84a, 84b. Thus, the first and second sealing beams 42a, 42b each form joins 46a, 46b as they move relative to the container 80, sealing the outer rim of the container 8 such that any product cannot escape through either opening 84a, 84b and such that the sealed opening may be watertight and/or gastight.

[0202] In contrast, the sealing beam source controls the position of the third sealing beam 42e such that the third sealing beam 42e moves relative to the container 80 along the dividing portion 125. Therefore, the third sealing beam 42e forms a join 46c along the dividing portion 125 of the container 80. This join 42e formed by the third sealing beam preferably connects the joins 42a 42b formed by the first and second sealing beams 42a, 42b. Therefore, the third sealing beam 42e seals the container 80 such that the first and second openings 84a, 84b cannot communicate (i.e. such that liquids and/or gases cannot pass between the two openings 84a, 84b across the seal).

[0203] Again the sealing beam source is configured to emit a sealing beam 42a, 42b, 42c incident on the container 100 and/or film overlying the container 80 local to each point of the pressing member 30 which engages the container 100 as the container 80 moves relative to the pressing member 30. Therefore, the openings 84a, 84b are sealed in a single pass of the pressing unit 30 relative to the container 80, there is no requirement to perform subsequent sealing steps.

[0204] It should be noted that—analogously to the example of FIG. 4—the sealing beam source discussed with reference to FIG. 5 may be configured to emit further sealing beams so as to seal multiple containers which are positioned close to each other and are simultaneously engaged by the pressing member 30 as the containers 80 travel relative to the pressing member. For instance, the sealing beam source may emit five or more sealing beams.

[0205] Additionally or alternatively, the apparatus 130 shown in FIG. 5 may be modified to seal containers with three or more openings. To achieve this, the sealing beam source may be configured to emit further sealing beams analogous to sealing beam 42e shown in FIG. 5 to seal any additional dividing portions which separate the additional openings.

[0206] The pressing member 30 in each of FIGS. 3a-3f, 4 and 5 is shown as a rectangular member which extends in a straight direction P. However, this is not essential. FIGS. 6a and 6b show alternative pressing members 32, 34 suitable for use in a container sealing apparatus

[0207] FIG. 6a shows a pressing member 32 which comprises an aperture 32a which is transparent to a sealing beam. For instance the aperture 32a may be a through hole, or formed of a material which is transparent to the sealing beam. The pressing member 32 and the aperture 32a extend linearly in direction R. A sealing member (not shown) may be configured to control one or more sealing beam(s) such that pass through the aperture 32a, and may be positioned along a scan line 44b which extends parallel to the direction R along the length of the aperture 32a.

[0208] Such a pressing member 32 may improve the effectiveness of the seal produced by the container sealing apparatus since a film may be pressed into contact with a container on either side of the location where a sealing beam is applied.

[0209] FIG. 6b shows a curved pressing member 34. The pressing member extends in the curved direction S. A sealing member (not shown) may be configured to control one or more sealing beam(s) such that the beam(s) may be positioned along a scan line 44c which extends parallel to the curved edge of the pressing member 34 such that the sealing beam is local to the pressing member 34 at each point along the scan line 44c.

[0210] In the examples discussed above with reference to FIGS. 2 to 6b, the sealing beam(s) move relative to the pressing member. In contrast, FIG. 7a shows an alternative embodiment of a container sealing apparatus 140 in which a pressing member 150 and a sealing beam 72 move together relative to the container(s) (i.e. containers 10) to be sealed.

[0211] The container sealing apparatus 140 receives containers 10 and a web of film 20, as in the example of FIG. 2. A transport system 50 is configured to transport the containers 10 in a direction D. Preferably the containers 10 and film 20 are supplied at similar rates.

[0212] The container sealing apparatus 140 further comprises a pressing member 36 controlled by a robotic pressing member control system 60 which is configured to move the annular pressing member via arms 62. Suitable machines for the pressing member control system include parallel robots such as the Quattro product line manufactured by Omron®.

[0213] The container sealing apparatus 140 further comprises a sealing beam source 70 configured to emit a sealing beam 72. The sealing beam source 70 is configured to control the path of the sealing beam 72 (e.g. using mirrors or other optics) such that the sealing beam 72 moves with (i.e. in tandem with or in a corresponding manner to) the pressing member 36. Therefore, although the pressing member 36 and the sealing beam 72 may move relative to the containers 10 to be sealed they are controlled such that they not move relative to each other.

[0214] As shown, the web of film 20 passes between the pressing member 36 and the containers 10. The pressing member 36 pushes the film 20 into contact with each container 10 as the container 10 is transported past the pressing member.

[0215] The pressing member 36 is formed as an annulus, having a central aperture 36a which extends through the pressing member 36. To join the film 20 to each container 10 the sealing beam source 70 emits a sealing beam 72 through this aperture 36a such that the sealing beam 72 is incident on the container 10 and/or the overlying film 20. An effective bond is created since the film 20 is pressed into contact with the surface of the container 10 by the body of the pressing member 36 which surrounds the aperture 36a and the sealing beam 72 is applied local to (i.e. close to) this region of contact.

[0216] As shown in the schematic diagram of FIG. 7b (which shows a plan view of the container sealing apparatus 140 sealing a container 10, omitting the film 20, the pressing member control system 60, the sealing beam source 70, and the transport system) the pressing member control system 60 and sealing beam source 70 may control (i.e. vary) the position of the pressing member 36 and the sealing beam 72 such that they move together around the perimeter of the opening 14 in the container 10 (e.g. around the rim 12 of the container 10). Consequently the film 20 can be joined to the container 10 along the path of relative movement between the sealing beam 72 and the container 10.

[0217] The container sealing apparatus 140 may also comprise a sensor (e.g. a camera) positioned upstream of the pressing member 36 and sealing beam source 70 configured to detect the position and orientation of containers 10 (or other containers), such that the movement of the pressing member control system 60, the sealing beam source 70 may be controlled based on the position and orientation of the containers 10 detected by the sensor. Equally in further embodiments the container sealing apparatus 140 may not comprise a transport system 50, and instead the containers 10 may be supplied manually.

[0218] An annular pressing member 36 such as the one shown in is particularly suitable for use in examples of container sealing devices in which the sealing beam 72 and pressing member 36 move relative to the container to be sealed. Regardless of the direction in which the pressing member 36 and sealing beam 72 move relative to the container the film in advance of the sealing beam is pressed into contact with the container so as to achieve an effective seal. However, this is not essential and other shapes for the pressing member may be used successfully.

[0219] Each pressing member 36 may be formed of a flexible and resilient material such as rubber to accommodate changes in the position of a surface of the container 10 (e.g. due to imperfections in the rim 12 of the container).

[0220] The figures discussed above show containers supplied with consistent spacings, and which are orientated such that their sides (and dividing portions in the case of FIG. 5) are either parallel or perpendicular to direction D of movement between the pressing member and the containers. This can simplify control of the sealing beams (e.g. as they travel along a predetermined path), however, it is not essential.

[0221] For instance, the apparatus may be used with containers which have curved sides or dividing portions. Equally, the orientation of containers and the spacing between containers approaching the pressing member may vary. In such embodiments a sensor may be provided to detect the orientation and/or position of containers approaching the pressing member, and the sealing beam source may be configured to emit sealing beam(s) based on sensing results of the sensor. For instance, once the orientation and position of a container is determined, the sealing beam apparatus may determine an appropriate path for the sealing beam to seal an opening in the container (e.g. such that a join surrounds the opening) and the sealing beam source may control the sealing beam to follow the determined path.

[0222] In further examples the container sealing apparatuses described above may comprise a cutting system configured to separate sealed containers from the film, or use individual sheets of film for each container. This could be achieved using a knife or the like but it is particularly convenient if cutting is achieved using a second cutting beam.

[0223] To extend the shelf life of the contents of a sealed container, any of the apparatuses and methods described above may be implemented in a controlled atmosphere. For instance, the apparatus may be a closed system filled with a purge gas that is maintained at, or just above, atmospheric pressure. As containers pass through such a system the purge gas will fill the internal volume of the containers so as to evacuate air from within the containers. This purge gas which is sealed in the container by the film is preferably inert and non-reactive with the packaged contents of the container. In cases where low oxygen levels are desired, purge gases which are heavier than air (e.g. carbon dioxide) are particularly preferred as they will displace oxygen from a container which has an upwardly facing opening. Alternatively, oxygen may be used as a purge gas in high oxygen packaging.