PACKAGING DEVICE

Abstract: An apparatus for packaging an item in a controlled atmosphere enclosure is provided. The apparatus includes a conveyor for continuously conveying a series of containers (14) along a defined path. The path has sequentially oriented first and second portions, and defines a first side border and an opposite second side border. The apparatus introduces a covering material (22) over the path of containers such that a space is created between the containers and the moving covering material. A vacuum gallery (46) is disposed substantially adjacent the first border for applying a vacuum to the space only in the first portion of the path. A gas gallery (40) is disposed substantially adjacent the second border for continuously introducing a selected gas into the space in both the first portion and the second portion of the path. The apparatus also includes a sealing head (34) for mating and sealing the containers with a corresponding section of the moving covering material in the second portion of the path to form a controlled atmosphere environment enclosure.

Description: The present invention relates to a device for packaging an item in a controlled atmosphere enclosure. It is known to package items, specifically selected food items, in packages having a controlled atmosphere. Normally, this controlled atmosphere is a low oxygen atmosphere, with the oxygen replaced by an inert gas. By eliminating the majority of oxygen from the package, the shelf life of a food item is greatly increased. Normally, the controlled atmosphere within the package is obtained in one of three conventional ways. The first way is to simply introduce the inert gas into the package, with the inert gas partially displacing the ambient oxygen in the package. The second way is to evacuate the package. The third way is to create a vacuum in the package and then to introduce the inert gas into the evacuated package. In any case, the package is sealed after the controlled atmosphere is established. EP-A-0 071 759 describes an apparatus for packaging an item in a controlled atmosphere enclosure, said apparatus comprising: means for continuously conveying a series of containers along a path, the path having a first side border and an opposite second side border, means for introducing a continuously moving covering material over said path of continuously conveyed containers such that a space is created between said continuously conveyed containers and said continuously moving covering material, first gas supply means disposed substantially adjacent said first side border for continuously introducing a gas into said space above said continuously conveyed containers, and means for mating and sealing said continuously conveyed containers with a corresponding section of said continuously moving covering material to form a controlled atmosphere environment within the sealed container. It has proved that apparatuses using such a method of simply introducing the inert gas into the packages work unsatisfactorily because it is extremely difficult to lower the oxygen content within the packages to a desirable level. It is therefore the object of the present invention to provide a continuously operating apparatus with which it is possible to lower the oxygen content with packages to lower values than they could be achieved before. The apparatus of the present invention comprises the above mentioned features of a known apparatus, i. e. among others the feature of a first gas supply means disposed substantially adjacent a first side border of a container path, and it is characterized by means disposed substantially adjacent the second side border of said container path for continuously applying a vacuum to a space above the continously conveyed containers. This construction makes it possible to suck oxygen from the containers and to introduce inert gas at the same time. This results in low oxygen content within packages which have been conveyed through the inventive apparatus. A very advantageous embodiment of the present application additionally comprises a second gas supply means disposed substantially adjacent a first end, to receive a series of containers, of the path and extending between the first side border and the second side border for introducing a selected gas into the first end of the path so that the gas is able to communicate with an interior region of each container as the containers enter the path through the first end. A similar feature is known from FR-A-2,228,670 describing an apparatus for packaging an item in a controlled atmosphere enclosure. The known apparatus comprises a gas supply means near the first end (see above definition of the conveying path), however, not substantially adjacent said first end. In the prior art apparatus, the covering material is already placed slightly above the full opening of a container, whereas in the inventive apparatus of the preferred embodiment the containers are not already covered by the covering material when said gas is supplied, as the gas supply means are substantially adjacent the first end. The combination of introducing gas already substantially adjacent the first end of the conveying path, and then additionally introducing gas and sucking oxygen along the further conveying path leads to excellent results in lowering the oxygen content within packages. Additional objects, features, and advantages of the invention will be apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived. Brief Description of the Drawings Fig. 1 is a diagrammatic illustration of the packaging device of the present invention in cross section; Fig. 2 is a diagrammatic plan view of the packaging device; Fig. 3 is a view taken along line 3-3 of Fig. 1 showing selected elements in cross section; Fig. 4 is a view similar to Fig. 3 taken down stream along line 4-4 of Fig. 1; Fig. 5 is a bottom view taken along line 5-5 of Fig. 3; and Fig. 6 is a diagrammatic illustration of the fluid flow characteristics of the present invention. Detailed Description of the Drawings Referring now to the drawings, and specifically to Fig. 1, Fig. 1 shows a packaging device 10 according to the present invention. The packaging device 10 includes a plurality of adjacent container supports 12 that are configured to support a series of containers 14 by their rims 15. The container supports 12 and containers 14 are configured to move in a continuous fashion in the direction of arrow 16. Although the mechanism for moving the container supports 12 and containers 14 in this continuous fashion is not shown, it will be understood that such mechanisms are well known in this art. Each container 14 is shown filled with a selected food product 18. It will be understood that the selected food product 18 has been positioned in each container 14 before the container 14 enters the illustrated packaging device 10 by associated machinery that is not shown. Again, this associated machinery for inserting the selected food product 18 into the containers 14 is well known in this art. The packaging device 10 includes a covering material or film supply reel 20 that contains a continuous length of film 22. A positioning pulley 24 is oriented to position the film 22 over the stream of moving containers as will be discussed in more detail below. The packaging device 10 also includes a first end 30 that is configured to receive the continuously moving containers 14. The packaging device 10 also has a second end 32 where the film 22 is mated with each container 14 and the containers 14 are discharged onto additional work stations. For illustrative purposes only, a sealing head 34 is shown disposed somewhat above the second end 32. Although only one sealing head 34 is illustrated, it will be understood that more than one sealing head 34 may be utilized. The sealing head 34 is a conventional heat sealing head that operates in a conventional manner to mate a portion of the moving film 22 with an associated moving container 14. Such heat sealing heads 34 are known in this art, and the function of the sealing head 34 will not be described in further detail here. A second gas introducing member or gas gallery 36 is disposed above the containers 14 at a position substantially adjacent the positioning pulley 24. The gas gallery 36 is oriented at an angle 38 with respect to the path of the containers to introduce a volume of a selected inert gas directly into each container 14 as the container 14 passes through the first end 30 of the packaging device 10. The operation of the gas gallery 36, and its cooperation with the other elements of the packaging device 10 will be discussed below in the discussion related to Fig. 2. Fig. 2 shows in greater detail the components of the packaging device 10 that cooperate to produce a controlled atmosphere environment in each sealed container 14. An elongated second gas gallery 40 is shown disposed along one side of the row of continuously moving containers 14. A gas supply 42 is coupled to the gas gallery 40 to provide gas to the gallery 40 as will be described below. In addition, the gas supply 42 is connected to the gas gallery 36 that is disposed across the first end 30 of the device 10. In the preferred embodiment, the selected inert gas is nitrogen. Therefore, the gas supply 42 is a nitrogen supply and provides nitrogen to both the gas gallery 40 and the gas gallery 36. An elongated vacuum gallery 46 is disposed on the opposite side of the row of continuously moving containers 14. A vacuum source 48 is shown which provides a vacuum to the vacuum gallery 46. The gas gallery 40 includes a series of expansion chambers 52 with outlets directed toward the row of moving containers 14. Each expansion chamber 52 is coupled by a supply tube 54 to an elongated conduit $5 that extends within the entire length of the gas gallery 40 and receives gas from the gas or nitrogen supply 42. A control valve 56 is provided for each expansion chamber 52 and permits the flow of nitrogen to each chamber 52 to be adjusted individually. Thus, by providing an individual control valve 56 for each expansion chamber 52, the amount of flow of nitrogen into each chamber 52 can be adjusted to any preselected level, or shut completely off if desired. The inner edge of the gas gallery 40 through which the individual expansion chambers 52 open defines a first side border or boundary means 58 which borders the row of continuously moving containers 14. As illustrated, the first side border 58 extends in parallel relation to the row of continuously moving containers 14. The first side border 58 is substantially vertical near the first end 30 of the device 10, and transitions to an angled face 60 near the second end 32. The function of the angled face 60 will be described in more detail below. The second gas gallery 36 includes two expansion chambers 61 that are similar to the expansion chambers 52. The expansion chambers 61 are coupled to a conduit 62 that receives gas from the gas source 42. Like the gallery 40, control valves 56 are provided to control the flow of gas to each expansion chamber 61. The vacuum gallery 46 includes a series of vacuum chambers 64 that are similar in shape to the expansion chambers 52 in the gas gallery 40. Each vacuum chamber 64 is coupled to a conduit 66 that extends within the entire length of the vacuum gallery 46 and is coupled to the vacuum source 48. A series of control screws 68 are provided to control and meter the introduction of vacuum from the conduit 66 to each vacuum chamber 64. By providing a control screw 68 for each vacuum chamber 64, the vacuum created within each vacuum chamber 64 can be adjusted to a preselected level, or it can be shut off completely if desired. The edge of the vacuum gallery 46 extends in parallel relation to the row of moving containers 14 and forms a second side border or boundary means 70. The second side border 70 cooperates with the first side border 58 to form boundary means for the row of moving containers 14. Like the first side border 58, the second side border 70 is vertical along a portion of the vacuum gallery 46 from the first end 30 toward a location approaching the second end 32. At the location approaching the second end 32, the vertical side border 70 transitions to an angled face 72. Like the function of the angled face 60, the function of the angled face 72 will be described below in more detail. Fig. 3 shows in more detail the orientation of the gas gallery 40, the vacuum gallery 46, the moving film 22, and the moving container supports 12 and containers 14. Specifically, each expansion chamber 52 in the gas gallery 40 includes an expansion volume 76 and a flow directing portion 78. The flow directing portion 78 opens into the first side border 58. Relatively high pressure nitrogen is provided to the expansion volume 76 from the conduit 55 by the supply tube 54 through a relatively small orifice 80 formed in the upper rear portion of the expansion chamber 52. The provision of the relatively large expansion volume 76 compared to the size of the orifice 80 permits the high pressure nitrogen to flow into the expansion volume 76 and to expand, thereby lowering its pressure. The resulting low pressure, but high flow of nitrogen is then directed through the flow directing portion 78 outwardly toward the moving containers 14. Because of the orientation of the expansion chambers 52 along the gas gallery 40, the low pressure, high flow of nitrogen creates a sheet or curtain of nitrogen that is directed outwardly away from the gas gallery 40 toward the moving row of containers 14. The characteristics of the flow of nitrogen from each expansion chamber 52 is described and illustrated in more detail below in the discussion related to Fig. 5. Referring to the vacuum gallery 46 opposite the gas gallery 40, vacuum is introduced into each vacuum chamber 64 from the conduit 66 through an orifice 82. As illustrated, the orifice is located in an upper rear portion of the vacuum chamber 64. The control screw 68 for each vacuum chamber 64 and associated orifice 82 controls the introduction of vacuum from the conduit 66 to each vacuum chamber 64. When the control screw 68 is in the open position, out of contact with the orifice 82 (as illustrated in Fig. 3), vacuum is introduced through the orifice 82 to the vacuum chamber 64. When the control screw 68 is moved into engagement with the orifice 82, the vacuum chamber 64 is isolated from the conduit 66 and thus isolated from the vacuum source 48 (as illustrated in Fig. 4). As discussed, it is advantageous to create a controlled atmosphere within each completed package for several reasons. In the preferred embodiment, where a selected food item 18 is being packaged in a container 14 with a film 22 to cover the container 14, it is advantageous to lower the oxygen content of the package, and to replace the removed oxygen with an inert gas, specifically nitrogen. In order to create the controlled atmosphere within the container 14, the gas gallery 36 first introduces a large quantity of nitrogen directly into the filled container 14 as it enters the first end 30 of the packaging device 10. By introducing a large volume of nitrogen directly into each filled container 14, a substantial portion of the oxygen within the container 14 is expelled. This is especially true of trapped pockets of oxygen that may be existing around the selected food product 18. As each container 14 passes the outlets of the gas gallery 36, the container 14 enters an area or portion of the device 10 where it is bounded on both sides by the gas gallery 40 and the vacuum gallery 46. In addition, the moving film 22 is positioned by the positioning pulley 24 over the moving container 14 and container supports 12 as the container passes under the positioning pulley 24. After the containers 14 pass the positioning pulley 24, a flush space 86 is created that is bounded below by the container supports 12 and containers 14, at the sides by the first side border 58 and second side border 70, and above by the film 22. Within this space 86 a controlled atmosphere is maintained and enhanced until the film 22 is mated with the container 14 to form a sealed, controlled atmosphere package. To maintain and enhance the controlled atmosphere already introduced into the filled container 14 by the gas gallery 36, nitrogen is introduced into the space 86 from the gas gallery 40, and specifically from the expansion chambers 52. Because of the design of each expansion chamber 52, and because of the orientation of the expansion chambers 52, a substantially continuous curtain of low pressure nitrogen is continuously introduced into the space 86. Simultaneously, a vacuum is created within each vacuum chamber 64 on the opposite side of the space 86. The vacuum within each vacuum chamber 64 assists in evacuating oxygen from the space 86 and the filled containers 14. By continuously introducing nitrogen from the nitrogen gallery 40, the evacuated oxygen is replaced by the incoming nitrogen. Thus, the simultaneous introduction of nitrogen and creation of a vacuum create and maintain a specified, controlled atmosphere within the space 86, and consequently maintains and enhances the controlled atmosphere within each filled container 14. The simultaneous application of nitrogen and vacuum is maintained as the containers 14 progress toward the second end 32 of the device 10. Referring to Fig. 4, as the containers approach the second end 32 (not shown) of the device 10, the sealing head 34 (not shown) moves downwardly to contact the film 22 and to move the film 22 into sealing engagement with the outer lip 15 of each container. After the sealing head 34 contacts the film 22, and the film 22 begins to be lowered toward the lip 15 of the container 14, it has been found that it is advantageous to discontinue the creation of a vacuum in the vacuum chambers 64 at this time. When the film 22 begins to lower over the outlet of the flow directing portion 78 of each expansion chamber 52, the introduction of nitrogen into the space 86 can be disrupted somewhat. It has been found that if the vacuum is continued, unwanted ambient air can be drawn into the space 86. This would be harmful because the controlled atmosphere created within the space 86 could be adversely affected. Therefore, as the film 22 begins to lower toward the flow directing portion 78 of the expansion chambers 52, the corresponding opposite vacuum chambers 64 are disabled from creating a vacuum by closing the screws 68. This configuration of the film 22 and corresponding disablement of the vacuum chamber 64 is illustrated in Fig. 4. It will be understood that as the containers progress further toward the second end 32, the film 22 is further lowered to mate with the lip 15 of the container 14 to seal the container 14. Because a controlled atmosphere has been created within the space 86 above and within the container 14, this controlled atmosphere is thus sealed in the container 14 by the film 22 to create a package having a controlled atmosphere environment. It will be understood from the above discussion that the controlled atmosphere has been created within each container 14 and space 86, and that the containers 14 have been sealed with the film 22 to capture the controlled atmosphere within each container 14 while the containers 14 have been continuously moving along the packaging device 10. Thus, the packaging device 10 of the present invention is able to create and maintain a controlled atmosphere within separate containers 14, and is able to seal the individual containers 14 while the containers 14 are continuously moving along a path in the packaging device 10. Thus, the device 10 of the present invention is able to maintain a high production rate while forming packages containing a controlled atmosphere. In the illustrated embodiment, the packaging device 10 is capable of creating packages in which the oxygen content is reduced to commercially desirable levels. Specifically, it has been found that the packaging device 10 of the present invention is capable of reducing the oxygen content in all package arrangements to less than five percent (5%) oxygen. The present invention is capable of reducing the oxygen content to less than one-half of one percent (.5%) oxygen when the selected food product is boiled water. These levels of oxygen content are considered to be commercially desirable levels in the food packaging industry. Continuing to refer to Fig. 4, it has been found that by angling the first side border 58 and second side border 70 to form angled faces 60, 72, respectively, that the transition of the film 22 over the first and second side borders 58, 70, is improved. Specifically, the angled faces 60, 72, permit the film 22 to gradually transition downwardly toward the lip 15 of the container 14. This gradual transition down the angled face 60 results in a smooth interruption of the in-flow of nitrogen from the corresponding expansion chamber 52. By interrupting as smoothly as possible the in-flow of nitrogen from the expansion chamber 52, the controlled atmosphere within the space 86 and container 14 is maintained. Fig. 5 illustrates the structure of the expansion chambers 52 and the characteristics of the flow of nitrogen in greater detail. Fig. 5 shows the point of introduction of nitrogen into the expansion chambers 52 through the orifices 80 which are located in an upper rear portion of each expansion chamber 52. As the nitrogen enters each expansion chamber 52 through the orifice 80, it transitions from relatively high pressure, high flow to relatively low pressure, high flow due to the known characteristics of expansion chambers in general. The flow directing portion 78 of each expansion chamber 52 includes three flow dividers or standoffs 90. The flow dividers 90 assist in directing the flow of nitrogen outwardly from the expansion chambers 52. Specifically, the flow dividers 90 act to direct the flow of nitrogen away from the flow directing portions 78 at substantially right angles. This flow of nitrogen from the flow directing portions 78 is illustrated by the solid arrows 92. By providing low pressure flow of nitrogen, and by accurately directing and controlling the flow of nitrogen from the flow directing portion 78, a laminar flow of nitrogen out of the expansion chambers 52 is achieved. This laminar flow of nitrogen is advantageous because it creates a low pressure curtain of nitrogen toward and into the space 86. By creating a laminar flow of nitrogen, turbulence is substantially eliminated in the out-flow of nitrogen from the flow directing portion 78. This lack of turbulence assists in maintaining the controlled atmosphere within the space 86. The broken arrows 94 indicate flow patterns that would otherwise take place were it not for the flow dividers 92. As illustrated by the broken arrows 94, the flow without the flow dividers 90 would not occur at right angles to the flow directing portions 78, and would not create the desired curtain of low pressure nitrogen with substantially no turbulence. Referring to Fig. 6, Fig. 6 illustrates the orientation of the first portion of the travel of the containers from the first end 30 toward the second end 32. Specifically, the flow path of the containers 14 has been divided for illustrative purposes into section A and section B. In section A, as illustrated in Fig. 3, the film 22 is positioned to create the space 86, and nitrogen is introduced into the space 86 as illustrated by arrows 100. In addition, vacuum is simultaneously created as indicated by the arrows 102. In addition, at the first end 30, nitrogen is introduced by the gas gallery 36 as indicated by arrows 98. In section B, the film 22 has been lowered toward the container 14 as illustrated in Fig. 4. At this point, the vacuum is disabled as indicated by the absence of arrows on the vacuum side. However, introduction of nitrogen is continued in section B as indicated by the continuing arrows 100. Thus, in section B, the in-flow of nitrogen is continued as the film 22 mates with the lip 15 of the container 14 to create the sealed package having a controlled atmosphere. By maintaining the in-flow of nitrogen during the sealing process, the possibility of the introduction of any ambient atmosphere to degrade the controlled atmosphere is minimized. Thus, the packaging device 10 of the present invention is capable of creating a controlled atmosphere in a series of continuously moving containers filled with a specified product. It will be understood that the present invention is not limited to packages containing food products. In addition to food products, other products and devices may be advantageously packaged in a controlled atmosphere environment. Examples of these devices and products are medical materials, medicine, certain adhesives, and certain explosive products. With modifications, the present invention is capable of packaging such products and devices in a controlled atmosphere package. Although the invention has been described in detail with reference to a preferred embodiment, variations and modifications exist within the scope of the invention as defined in the following claims.

Claims: An apparatus (10) for packaging an item in a controlled atmosphere enclosure, the apparatus comprising means (12) for continuously conveying a series of containers (14) along a path, the path having a first side border (58) and an opposite second side border (70), means (20) for introducing a continuously moving covering material (22) over said path of continuously conveyed containers (14) such that a space (86) is created between said continuously conveyed containers (14) and said continuously moving covering material (22), first gas supply means (40) disposed substantially adjacent said first side border (58) for continuously introducing a gas into said space (86) above said continuously conveyed containers (14), and means (34) for mating and sealing said continuously conveyed containers (14) with a corresponding section of said continuously moving covering material (22) to form a controlled atmosphere environment within the sealed container (14), characterized by means (46) disposed substantially adjacent said second side border (70) for continuously applying a vacuum to said space (86) above said continuously conveyed containers (14). The system of claim 1, wherein the path includes a first end (30) configured to receive the series of containers (14), and wherein the apparatus (10) further comprises second gas supply means (36) disposed substantially adjacent the first end (30) of the path and extending between the first side border (58) and the second side border (70) for introducing the selected gas into the first end (30) of the path so that the gas is able to communicate with an interior region of each container (14) as the containers (14) enter the path through the first end (30). The system of claim 2, wherein the first and second gas supply means (40 and 36) are aligned in a substantially perpendicular relation so that the gas introduced by the first gas supply means (40) flows in a first direction and gas introduced by the second gas supply means (36) flows in the first direction at substantially a right angle to the first direction. The system of claim 2 or 3, wherein the means (12) for continuously conveying the series of containers (14) along a path moves the containers (14) along a predetermined movement plane, the first gas supply means (40) being situated to direct the flow of gas in a transverse flow plane in substantially spaced-apart parallel relation to said predetermined movement plane, the second gas supply means (36) being oriented at a predetermined angle with respect to the first gas supply means (40) to direct the flow of gas from the second gas supply means (36) in a longitudinal flow plane oriented to intersect said predetermined movement plane and said transverse flow plane. The system of claims 2 to 4, wherein the second gas supply means (36) includes a gas discharge nozzle (61) having a discharge opening width sufficient so that gas is introduced into the space (86) of each container (14) along the full lateral width of each container (14). The system of claim 5, wherein the moving means (12) moves the containers (14) along a predetermined movement plane, the gas discharge nozzle (61) being oriented at a predetermined dihedral angle (38) with respect to the predetermined movement plane so that gas introduced from the second gas supply means (36) is aimed relative to the series of containers (14) to enter an interior region of the containers (14) at a selected angle, thereby enhancing development of the controlled atmosphere environment in the interior region of each container (14).

Inventors: RAQUE GLEN, ROBINSON EDWARD A.
Applicants: RAQUE FOOD SYSTEMS, INC.
Application year: 1988
Main classification: B65B31
IPC codes: B65B31