KR100320356B1 - Packaging systems for increased food product shelf life - Google Patents

Abstract

The tray has a circumferential flange with one or more raised ledges to secure a pair of thin films surrounding the tray. The upper thin film may be attached to the concave lip of the second ledge or flange without being bonded to the lower thin film except through the tray. The two attachment surfaces may be separated by grooves or by placing them at different heights to facilitate mounting of the upper membrane during the continuous manufacturing process of the packaging container. Methods and apparatus for changing the gas atmosphere of a packaging container transfer a plurality of trays between a plurality of stations arranged in a circle using a rotating conveyor. The tray can be loaded onto a receiving platform by placing the tray on a movable bed that can be reciprocated downward to maintain the tray in a removable platform inner slot. The platform can be removed from the conveyor so that the platform can be centered at any station by moving the platform from the conveyor and being guided to be exactly aligned at a particular station. The packaging container is replaced with a desired gaseous atmosphere of low oxygen content and sealed. Since this is done continuously, the thin film is separated from the continuous web. Packaging containers, packaging methods, and packaging devices are used to exchange the gas atmosphere to create a desirable gaseous atmosphere that extends the packaging and product shelf life of large quantities of meat products. The packaging container is abutted along the sealing surface, including a pair of hemispherical cup shaped members made of a relatively rigid material. Upper packaging portion 318 and lower packaging portion 310 include flanges 312 and 336 that are used to facilitate the opening as well as the formation of a packaging container. The reciprocating tube 320 may be reciprocated downward to allow the upper and lower packaging portions to be separated between the upper and lower packaging portions to allow gas exchange, and then to fold the upper packaging portion onto the lower packaging portion for sealing connection.

Description

PACKAGING SYSTEMS FOR INCREASED FOOD PRODUCT SHELF LIFE}

The present invention relates to an apparatus for packaging food, a packaging container, and a packaging method, and which enables the packaged product to be changed to other conditions after keeping the packaged product under a certain environment. For example, during transportation, the packaged food is kept in an inert gas atmosphere, and then the packaged food will be exposed to the atmosphere when the packaged product reaches a supermarket or other retail outlet. A wide variety of foods can be packaged according to the present invention and a gas modified to allow meat to be delivered in a relatively inert atmosphere and turned red by exposure to oxygen when the delivered meat reaches a retail store. It is particularly useful in connection with packaging meat in packaging containers under the atmosphere.

Traditionally, meat products have been slaughtered and packaged individually in supermarkets or other retail outlets. This structure has long been recognized as a very inefficient and expensive structure. Instead, it would be desirable to pack the meat in an efficient facility where the meat could be slaughtered and gain the economic benefits of mass production and then transported to individual supermarkets or other retail outlets.

In the past, this desirable goal could not be achieved because most consumers like to buy red meat when exposed to oxygen. However, meat only stays red for a day or two. After that, most consumers turn to unwanted purple. Therefore, if meat is slaughtered and packaged in one place and then transported to another place for sale, the meat will turn purple until the packaged product reaches a retailer, making the sale inefficient.

To solve this problem, the meat product is placed in a first atmosphere (e.g., inert gas atmosphere) during transportation, and the meat product is placed in a second atmosphere (e.g. atmosphere exposed to air) when it is waiting for sale at a retail store. Efforts have been made to maintain food. None of these technologies are believed to have achieved significant commercial results yet. Therefore, it is desirable to develop packaging containers that allow meat to be prepared at a distance and subsequently sold after a few days.

One problem is that consumers will be reluctant to spend too much on elaborate packaging, while the need for such packaging increases. Therefore, it is extremely desirable to develop a packaging container which is switchable between two very different packaging states and which is very economical. Moreover, it is also advantageous to make such packaging containers look similar to the packaging containers now familiar to consumers.

One attempted solution to this problem is to use a double layer cover over a plastic packaging container containing meat products. The top cover is impermeable to gas, and when removed will expose the air permeable bottom cover. Thus, the packaging container can be transported as it is, so that the inside of the packaging container can be maintained in an inert gas atmosphere during transportation. The top cover is then removed from the supermarket, leaving the bottom cover. Because the lower cover is oxygen permeable, the meat may turn red by oxygen.

Typically, the double layer packaging container is obtained by adhesively fixing the upper layer to the lower layer and then heat sealing or otherwise fixing both layers to the packaging container itself. For example, when the top layer is removed, adhesive remains in the bottom layer, adversely affecting the oxygen permeability of the bottom layer. Also, when removing the top layer, it is difficult to avoid tearing or otherwise removing the bottom layer. Moreover, it is difficult to produce such packaging containers that are adapted to separate the two layers.

While many sophisticated techniques have been devised to avoid interlayer interference, these methods generally add to packaging cost and complexity. Moreover, removing the upper layer (sealed to the lower layer) without removing the lower layer is problematic. Many attempts have been made to overcome this problem, but commercially useful solutions have not been achieved.

In the past, hemispherical meat packaging containers were used to hold large chunks of meat, such as chicken or roast meat. However, this vessel had many drawbacks.

It is necessary to adjust the atmosphere in the meat packaged product to delay the aging of the food and to extend the shelf life in the supermarket. For example, by providing a low oxygen atmosphere, the food shelf life can be extended from a few days to perhaps two weeks or more.

In order for consumers to feel comfortable with food packaging, most of the food must be made visible to the consumer. In order to maintain the desired atmosphere around the packaging container, a somewhat larger packaging container than food is required. However, for large and relatively heavy meat products, it is difficult to keep the food in the container while making the food look glamorous at intervals around the food.

Moreover, since the consumer typically wants to be able to observe the food, the interval is shown to the consumer. The consumer can believe that the packaging is too large and wasteful. Moreover, if the packaged product is substantially larger than the food, the food can be moved around during transportation and handling and the packaging container itself can be recessed or otherwise damaged.

In the past, deep drawing packaging containers could be used for this type of packaging. However, deep drawn packaging containers are difficult to form in large sizes and serious deformations can occur in the packaging material. Such packaging containers are particularly susceptible to formation of thin areas and prone to dents and collapses of the corners.

US Pat. No. 4,902,902 discloses a nest for receiving a container to which a lid is attached after filling, the lid being sealed to the container by a sealing head in relation to the nest. For the purpose of facilitating the filling of gas into the vessel, a series of vacuum nozzles are used to hold and lift the top cover of the vessel. US Patent No. 2423975 discloses a packaging device in which a container is provided with a loose lid thereon. Once the vessel is in place, a bell is lowered onto the vessel to provide the chamber with a gas filling operation therein.

International patent application WO91 / 03407 discloses a packaging container for a perishable product in which the lid seals the packaging container and consists of a transparent plastic lid on the base. German application DT1810958 discloses an item of packaging container with a peel-off lid attached to a base. Different sizes of tabs are attached to both the lid and the base so that the tabs of the lid are readily available.

U.S. Patent No. 3508373 discloses a method of removing air from a packaging container and exchanging it for another gas. Air is removed from the packaging via an opening on one side of the packaging, so that other gas is introduced into the packaging at a point spaced from the opening using an absorption tube at that opening. U. S. Patent No. 3225889 discloses a packaging machine including a horizontal stacking wheel having a series of circumferential holes suitable for supporting an open container to be filled.

European patent application 3328 discloses a method for packaging a product in which gas exiting the upper space of the container is removed from the container. Thus, the opening from which the gas is removed is closed, and the closure is deformed inward with respect to the product to reduce the upper space so that the upper space is removed. U.S. Patent No. 3551668 discloses a double sealed packaging container that includes a container in which an inner lid member is hung at an open end of the container. The outer cover is sealed to both the container flange and the inner cover member. British patent application 2251540 discloses a process for storing food, which consists of entering food into a tray with sidewall steps forming both first and second supports extending around the tray. The fine pores of the lid are attached to the first support, the food is heated in the tray and then cooled, and the tray is then sealed by attaching the outer lid to the second support.

Therefore, it was desired to mold hemispherical packaging containers without using the deep drawing plastic molding technique. In a hemispherical packaging container, the product can protrude over a sealing flange connecting the upper and lower regions of the container. It is also possible to manufacture the packaging container area from other materials according to the needs of the particular packaging. For example, it is also preferable to make the bottom part with a foamable material and the top part with a transparent plastic.

The requirements of relatively large packaging containers made of relatively rigid packaging materials do not seem to match the extra space in the containers required for conventional gas exchange techniques to extend shelf life. Thus, most conventional large-capacity foods are simply overlaid with plastic packaging, so supermarkets have to bear the additional costs incurred from meat loss.

Therefore, it is highly desirable to provide relatively rigid hemispherical food packaging containers, packaging methods, and packaging devices in which relatively large chunks of meat can be efficiently packaged in the desired gas atmosphere.

1 is a plan view of one embodiment of a packaging container 10 according to the present invention.

2 is an enlarged side cross-sectional view of the packaging container taken along line 2-2 of FIG.

3 is a plan view of another embodiment of a packaging container 10 according to the present invention.

4 is an enlarged side cross-sectional view of the packaging container 10 taken along line 3-3 of FIG.

5 is a schematic view showing a method for assembling the packaging container 10 of FIG. 1.

6 is a cross-sectional view schematically shown along line 6-6 of FIG.

7 is a front view of the embodiment shown in FIG.

8 is a partially enlarged plan view of the embodiment shown in FIG. 6 and sends a loading area for containing the tray to be packed;

9 is a front view of the part shown in FIG. 8;

FIG. 10 is a front view corresponding to the front view shown in FIG. 9 showing after a row of trays are disposed on the receiving platform; FIG.

FIG. 11 is a plan view of the portion shown in FIG. 10; FIG.

12 is a vertical cross-sectional view partially cut away to show two stations rather than four stations with the vacuum and gas supply means removed;

FIG. 13 is a view corresponding to FIG. 12 and showing a state in which the platform is removed from the rotating arm. FIG.

14 is an enlarged plan view of a quick disconnect tooling at station 122C.

15 is an enlarged sectional view taken along line 15-15 of FIG. 14;

16 is a partial side view of an unloading station.

17 is a partial side view of the unloading station after the platform has been raised to the 'rising' position.

18 is a plan view of the embodiment shown in FIG. 17 showing after the tray has been pushed into the unloading conveyor.

19 is an enlarged fragmentary sectional view of the bottom of a surge tank.

20 is a simplified cross-sectional view showing three steps in one embodiment of a packaging process according to the present invention.

21 is a partially enlarged plan view of the packaging container shown in FIG. 20A.

22 is a partially enlarged plan view of the packaging container shown in FIG. 20B.

FIG. 23 is an enlarged cross-sectional view showing one embodiment of a packaging apparatus for performing the process steps shown in FIG. 20B.

24 is an enlarged cross-sectional view of the packaging device of FIG. 23 in a position to perform the process steps shown in FIG. 20C.

25 is an enlarged plan view of another embodiment of the packaging container in the direction shown in FIG. 20B.

<Explanation of symbols for main parts of drawing>

10: packing container

12: tray

14, 16: thin film

18: base

20: flange

22, 24, 52: ledge

68: cutting press

70: web

74, 76: thin web

120: packing machine

122: station

124: platform

126: slot

These and other objects can be achieved by an apparatus comprising a plurality of packaging stations and for producing a packaged container in a modified gas atmosphere. Among these stations there is at least one station for loading food in a tray. Rotary conveyors move trays from one station to the next. Rotary conveyors include a platform that supports a number of trays. One of the packaging stations is suitable for loading trays into the platform. Another of those stations is suitable for unloading the tray from the platform. The present invention includes an apparatus for exchanging the ambient atmosphere of the tray with an atmosphere of low oxygen content before the tray is covered with a packaging film.

In another aspect of the invention, a method of packaging under a modified gas atmosphere includes loading a plurality of trays on a rotating conveyor. The tray is arranged between a plurality of stations arranged in a circular path. The atmosphere in the tray is released when food is received. The tray is covered with a membrane to maintain an atmosphere of low oxygen content. The tray is then lowered from the rotating conveyor.

In another aspect of the invention, the flexible first thin film is sealed in a tray. The flexible second thin film is sealed in a tray over the first thin film. The membranes are fixed to the trays at separate positions of the trays. The films are substantially coplanar with one another and can be removed from the tray independently of each other.

Referring to the drawings, like parts have like reference numerals throughout the several views, and a packaging container 10 for storing one or more foods 'A' is shown in FIGS. 1 and 2. The packaging container 10 is particularly advantageous for storing red meat. The packaging container 10 includes a relatively rigid tray 12, a thinner film 14 having better permeability, and a thinner film 16 having a lower permeability. The membranes 14, 16 are connected to the tray 12 along the perimeter.

The tray 12 may be made of a relatively rigid plastic that is molded by a method such as thermoforming. The tray is preferably made of a gas impermeable material and may be formed from a polymer sheet monolith. Polymer sheets include polyvinyl chloride, nylon, fluorohalocarbon, polyurethane or polymer material composites, and the polymer material composites include PVC; PVC and polyolefins; PVC and saran; PVC, saran, polyolefin; PVC, saran, ethylene vinyl acetate copolymer; Polystyrenes, sarans and polyolefins; Polystyrenes, sarans and copolymers; Nylon, saran, polyolefin; Polyolefins, sarans and polyethylenes; Polyesters, sarans and polyolefins; Polycarbonates, sarans and polyolefins; Or other various materials known in the art. The tray 12 is preferably formed of a material that blocks oxygen well, has adequate thermoforming, is sufficiently strong, and facilitates attachment of other materials to the tray.

In the illustrated embodiment, the tray 12 is shown as being generally rectangular, but the present invention also applies to other shaped trays 12, such as round shapes (not shown). Tray 12 includes a curved base 18 forming a cavity for receiving food A and a double flange edge 20 extending along the base 18.

The double flange edge 20 forms a pair of ledges 22, 24 separated by grooves 26. The outermost edge 28 of the flange 20 may be curved downward. In the illustrated embodiment, the base 18 and the flange 20 can be molded in one piece. In one exemplary embodiment, the top surfaces of the ledges 22, 24 may be located in a single plane, such that the ledges 22, 24 and the membrane 14, 16 are at the top of the packaging container 10. It is provided with an almost flat surface. In this regard, the tray 12 may be formed of a porous foam material, which is hot pressed to uniform the height of the ledges 22 and 24 and the thickness of the tray 12. Such a flat face makes it possible to more reliably connect with the thin films 14 and 16 and to facilitate stacking of multiple packaging containers on top of each other.

The more permeable layer or thin film 14 is preferably composed of a flexible elastic material, such as a flexible plastic material, in order to allow gas exchange through the membrane if required by a particular application. With regard to the coloring of the red meat, the thinner film 14, which is more permeable, is generally preferred for very smooth communication with the surrounding atmosphere. A wide variety of materials can be used for such thin films 14, and may be polyvinyl chloride, polycarbonate, cellophane, polypropylene, polyethylene, polyethylene copolymers, ionomer films or any gas permeability known in the art. Substances and the like. In addition, the thin film 14 may be formed of a microporous film having a hole formed by a chemical or mechanical method. The thin film 14 only needs to be strong enough to prevent the hole from being used during use.

The thin film 14 is fixed to the tray 12 at the inner ledge 24. In this regard, the thin film 14 is preferably a material that can be heat sealed to the tray 12. However, it is also possible to adhesively fix the circumferential edge of the thin film 14 to the inner ledge 24. As mentioned above, the thin film is sealed in a tray, which means that it is not partially frictionally bonded but is heat-sealed or adhesively fixed. Grooves 26 are formed between the ledge 22 and the ledge 24. The groove 26 helps the thin film 14 to be secured to the inner ledge 24. In particular, after the thin film 14 spans the tray 12 and the ledges 22 and 24, the thin film 14 is fixed to the inner ledge 24, after which a cutting press is applied to the thin film 14 as described below. The edges are cut and arranged by moving into the grooves 26 through). Although the groove 26 is shown in U-shape in FIG. 2, the groove may be V-shaped, semi-circular, rectangular, and may also be formed in any other shape depending on appearance, function, and other reasons. The thin film 16 having low permeability is also preferably made of a flexible elastic material such as a flexible plastic material. However, the thin film 16 is a material having a relatively low gas permeability, and is preferably selected from the group consisting of polyester, nylon, cellophane, polypropylene, polyvinyl acetate, saran, or a mixture of these materials. It is advantageous that the thin film 16 having such a low permeability cannot be gas permeable.

The low-permeability thin film 16 is again detachably secured to the outer ledge 22 by heat sealing, adhesive techniques, or other known methods. After the low-permeability thin film 16 is fixed to the outer ledge 22, the cutting press is moved downward to pass through the thin film 16 at the outer position of the outermost outer edge 28 as described later. Clean up the edges of the 16. Instead, if desired, the thin film 16 may be trimmed at its edges before being sealed to the outer ledge 22. In any case, it is desirable to cut and arrange to leave the protrusions 19, which are later lifted by such protrusions 19 to peel the thin film 16 back from the connection with the outer ledge 22. This is to facilitate the separation. When fixed to the ledge 22, the low permeability membrane 16 is not connected to the high permeability membrane 14 at all except for frictional or indirect connections through the tray 12. Accordingly, the thin film 14 having high permeability can be conveniently separated from the packaging container while leaving the thin film 14 having high permeability in place. Although the thin films 14 and 16 are not connected to each other, the thin films 14 and 16 are positioned substantially coplanar with each other and face to face, each of which is under some elastic tension. It is beneficial.

After both of the thin films 14 and 16 are fixed to the tray 12, the inside of the packaging container 10 can be maintained in a desired gaseous atmosphere to benefit the food A contained therein. This can be accomplished by sealing the closed packaging container in the desired gaseous atmosphere. In the case of red meat product, the initial gaseous atmosphere of some embodiments may contain a relatively low concentration of oxygen. To reduce the exposure of food (A) to oxygen, for example, a gas containing significant concentrations of carbon dioxide or nitrogen can be maintained in the packaging container. As a result, meat products are prevented from discoloring for a longer time.

When food arrives at a supermarket or other retail store, it is desirable to remove the thin film 16 having low permeability. This can be conveniently removed by grasping the edge of the upper membrane 16 and pulling it up. Since the thin film 16 is not connected to the other thin film 14, it can be easily removed from the rest of the packaging container 10.

Thereafter, the packaging container 10 exists without the thin film 16 having low permeability, and includes only the thin film 14 and the tray 12 having high permeability. In embodiments of storing meat products, it may be desirable to allow oxygen to pass through the highly permeable thin film 14 to maintain the original color of the meat product. Thus, once the low permeability thin film 16 is removed at the retail store, the red meat product A may become red by exposure to high concentrations of oxygen.

In other alternative embodiments, for certain applications, both thin films 14 and 16 may be formed of a substantially impermeable material. Such a configuration may be useful, for example, in the case of alternative labeling schemes. In such embodiments, the upper thin film may be labeled by an initial meat packer for intermediate merchants rather than the final consumer of meat, and the lower thin film may be labeled by a supermarket or retail store, such as an advertising label. In this case, the outer thin film 16 may be easily removed with respect to the inner thin film 14.

Another embodiment of the packaging container 10 is shown in FIGS. 3 and 4. In particular, in this embodiment, the portion of the ledge 52 is configured to be surrounded by a concave lip 54 having an outermost edge 56. In this embodiment, the highly permeable membrane 14 is first secured to the ledge 52 and the cutting press is pushed down through the membrane 14 at a position allowed by the concave lip 54 radially outward of the ledge. To clean up the cutting edges. Subsequently, a thin film 16 having low permeability is attached over the tray 12 and attached to the lip 54. The thin film 16 having low permeability cuts and trims its edges by moving a cutting press (not shown) down through the thin film 16 at a position outside the outermost edge 56. Therefore, the surface area of the thin film 16 having low permeability is wider than the surface area of the thin film 14 having high permeability, whereby the thin film 16 can cover other thin films 14 from the outside. The thin film 16 may be cut to provide a projection 58, and thus a thin film having low permeability by lifting the projection 58 and peeling the membrane 16 back from the connection with the edge 56. (16) can be easily removed. In addition, the thin films 14, 16 are substantially coplanar with faces adjacent to each other, and each film is in a slight elastic tension state.

In this embodiment, the desired gaseous atmosphere can be maintained in the packaging container 10 in the same manner as described above for the previous embodiment. When the product reaches a supermarket or other retail store, the low permeability membrane 16 can be easily removed by grasping the protrusion 58 of the membrane 16 and pulling it up. Thereafter, the packaging container 10 is present without the thin film 16 having low permeability, as in the above-described embodiment, and only includes the thin film 14 and the tray 12 having high permeability.

Hereinafter, an exemplary molding process of the packaging container 10 will be described with reference to FIG. 5. Referring to the right side of FIG. 5, the food A is filled into the tray 12 held from below by the rigid shape matching carrier 60. Oxygen is then discharged from the packaging container 10 and the low oxygen content transport gas is refilled. A web 70 made of a highly permeable thin film 14 is released from the pair of rolls 62 and 64 and placed on the tray 12. The highly permeable web 70 is fixed to the inner ledge 24 by a heat sealing machine 66 or the like. Thereafter, the web 70 is cut using a conventional cutting press 68. In the embodiment shown in FIGS. 1 and 2, the web 70 is cut at a position proximate to the groove 26. In the product of FIGS. 3 and 4, the web 70 is cut at a position above the concave lip 54, where the lip 54 itself serves as a groove or recess. In either case, it is evident that the groove 26 or lip 54 facilitates cutting or removing the thin film 14 from the web 70 located in place on the packaging container 10. Heat or ultrasonic energy or the like may be applied to the web 70.

In the next station, the web 76 made of the low permeability thin film 16 is released from the pair of rolls 72 and 74 and placed on the packaging container 10. In the embodiment of Figures 1 and 2, the low permeability thin film 76 is secured to the ledge 22. In contrast, in the embodiment of FIGS. 3 and 4, the web 74 of the low permeability thin film is fixed to the outermost edge 56. In both cases, this fixing is done using conventional methods such as using the heat sealing machine 42. At this time, the transportation gas is enclosed in the packaging container 10. Finally, web 76 is cut by conventional cutting device 78. In the embodiment shown in Figs. 1 and 2, the slightly outer side of the edge 28 is cut off. In the embodiment of Figs. 3 and 4, the slightly outer side of the outer edge 56 is cut off. This leaves the protruding piece 19 or 58 of the material 16 having low permeability, which can be removed by the user holding the protruding piece when the user wishes to remove the thin film 16.

After assembling the packaging container 10, the packaging container can be transported to a place for retail sale. Packaging containers remain in the retail store's equipment until display. At this time, the thin film 16 with low permeability is peeled off and discarded. After a short retention period, the packaging will be displayed for retail sale. The holding period is necessary to allow oxygen to be absorbed into the packaging container through the highly permeable thin film 14. If the meat turns red, it can be displayed for sale.

Through the provision of grooves 26 or lip 50, both membranes 14 and 16 can be attached to the same tray 12 in a manner that allows for high speed manufacturing. Although the simplified process shown in FIG. 5 proposes a method of packaging foods continuously, this approach will apply to conventional packaging devices as well.

The thin film having high permeability is preferably capable of sufficiently maintaining a desired gaseous atmosphere in the packaging container until the thin film having low permeability is held in place and functions. This is especially true for high speed systems. In some cases, however, it may be advantageous to provide a particular gaseous atmosphere between the high permeability membrane and the station covering the low permeability membrane.

This method can also be used to make packaging containers in which both membranes are impermeable.

As shown in FIG. 6, the packaging machine 120 includes four stations 122. While the packaging machine has shown an embodiment including four stations, it should be appreciated that one or more of the indicated stations may not be used, and in some embodiments it may be possible or desirable to have more or fewer stations than four. do. Four stations 122 work on packaging containers that circularly move from one station to the next.

The packaging container to be produced is held on a platform 124 that includes slots 126 for receiving four packaging container trays in the illustrated embodiment. Various types of packaging containers can be used, including the packaging containers described herein.

The platform 124 is supported on the mounting arm 128, which is connected to the rotatable ring 130. The ring 130 is driven by a drive mechanism 132, which drive mechanism may be any conventional mechanism, but is illustrated as a drive chain and a motor device as shown.

As shown in FIG. 7, the entire packaging machine 120 is supported on the upper surface of the base 134 on the leg 136. The base 134 also supports a surge tank 138, which supports the hanger assembly 140. The surge tank acts as a central support for installing the ring 130 and drive mechanism 132. Base 134 and hanger assembly 140 may be used to support various devices disposed in station 122 that operate on food trays contained within platform 124. For example, as shown in FIG. 7, the tray loading mechanism 142 is connected with the station 122a and supported on the base 134. Similarly, tool assembly 144 has its top 146 mounted on hanger 140 and its bottom 148 mounted on base 134. The top 146 includes a housing or chamber 147 and the bottom 148 includes a housing or chamber 149.

The tray stacking mechanism 142 shown in FIG. 10 includes a tray conveyor 150 and a tray stacker 152. Conveyor 150 may be a conventional belt conveyor, the tray 155 is moved on the tray conveyor 150. The tray is aligned by a braking bar 154 powered by the cylinder 156. The tray 155 may proceed to the second braking bar 158 at predetermined intervals, such that another additional tray may occupy the position preempted by the tray 155. The braking bar 158 is controlled by the second cylinder 160. The tray 155 may preload the food to be packaged.

Below the platform 124a is a cylinder 162 for moving the bed 164 up and down. Bed 164 includes a brake 166 at its inner end. Each bed 164 is designed to receive a tray 155 exiting the tray conveyor 150 and lower it into the slot 126 of the platform. Thus, there may be a number of instruments 160, 164 and one instrument is disposed for each slot 126 of platform 124a.

In the illustrated embodiment, station 122b is an inactive station that is not used. However, in other applications, it may be desirable or necessary to perform all or some of the tasks performed at other stations at station 122b. For example, station 122b may be used to fill food into tray 155.

Station 122c includes tool assembly 144 consisting of top 146 and bottom 148. As shown in FIG. 7, the upper chamber 147 is mounted on the instrument 168 to be lowered towards the platform 124 or raised away from the platform by the instrument. Similarly, the lower chamber 149 is mounted to the instrument 170, which raises or lowers the lower 148 toward the underside of the platform 124. If desired, the upper chamber 147 or the lower chamber 149 may be fixed.

12 and 13 show platform 124 mounted on arm 128. As shown in FIG. 12, platform 124 is mounted on arm 128 by a number of upright pins 172. Each pin 172 includes a tapered top 174 that fits and engages with the tapered portion 176 in the underside of the platform 124. Thus, platform 124 is removably disposed on arm 128 by pin 172.

The lower chamber 149 includes a pair of upright pins 178 having tapered portions 180 that engage the holes 182 of the platform 124. Thus, when lower chamber 149 moves upward to engage platform 124, tapered portion 180 of pin 178 engages hole 182 in platform 124. In this way, the platform 124 is placed in the station in exact alignment with the station 122c. As shown in FIG. 13, the lower chamber 149 actually lifts the platform 124 into its pins 172 to align it correctly. As shown in FIG. 13, the upper chamber 147 and the lower chamber 149 have a built-in seal 184 that provides an airtight portion on the upper and lower surfaces of the platform 124.

As shown in FIG. 15, the structure of the upper and lower portions 146, 148 of the tool assembly 144 includes a sealing machine 186, a cutter 188, and a web winding system 190. The thin film or web 192 is released from the roll 194 and travels inside the tool assembly 144 to the waste roll 196. Web 192 may be made from any plastic thin film for food packaging, including composite thin films of plastic, aluminum foil, paper, or cardboard.

The thin film 192 can be placed over the tray 155 to seal the tray with a sealing machine 186 mounted on the shaft 208. The sealing bar reciprocates vertically and vertically for an appropriate time to seal the thin film 192 to the tray 155. Although various sealing machines 186 may be used, certain conventional sealing machines heat seal the thin film to tray 155 using an electrical resistance heater 200. The vertical movement range of the shaft 208 is controlled by the intermediate braking portion 202 under the influence of a conventional fluid energy source. The intermediate braking portion 202 is part of the tube 198 which is hermetically fixed to the shaft 208.

The sealing machine 186 is detachable from the instrument by simply unscrewing the nut 206 for repair or cleaning, if desired. When this is done, the shaft 208 and the sealing machine 186 can be separated downward from the instrument.

The cutter 188 includes a pair of blades 210 arranged to enter into the grooves 212 of the platform 124. These blades completely cut the thin film 192 around the upper periphery of the tray so that the thin film matches the shape of the tray 155. Of course, conventional cutting techniques, including cutting or heat cutting techniques, can be used. In addition, one or more webs or thin films may be cut and attached to the tray 155. Similar to the sealing machine 186, the cutter 188 also reciprocates up and down around the sealing machine 186. The cutter is controlled on the arm 216 by the brake 214 under the influence of a conventional fluid energy source.

The cutter 188 also includes an internal coolant circulation passage 218. A passage 218 connected to an external cooling liquid source provides a medium for cooling the cutter 188. The cutter 188, which is very close to the sealing machine 186, has the potential for heat related malfunction. By cooling the cutter 188, the accuracy of the cutting operation can be maintained even in a relatively high temperature environment.

The lower chamber 149 has a gas exchange passage 230 embedded in a lower surface thereof, while the upper chamber 147 is provided with a gas exchange passage 232 on its side wall. The bottom 148 may include a filler 234. Each platform 124 has a plurality of gas exchange passages 236. The gas exchange passage 232 communicates with the vacuum source through the quick disconnect device 238 shown in FIG. 14. The passage is secured to the upper chamber 146 by the threaded knob 240. Similarly, device 242 is connected to lower chamber 149 by threaded knob 244 to exchange gas through opening 230.

In FIG. 14, the connection to the top 146 and the bottom 148 is quick removable, so that the machinery associated with the given station 122 can be easily separated from the rest of the machine 120. Moreover, the connection to power and fluid is likewise quick detachable. Thus, the connection as shown at 220 can be separated by pulling or unscrewing the connection, after which the mechanism 246 holding the upper and lower chambers 147, 149 can be separated in the same way, The upper and lower chambers 147 and 149 can be quickly separated.

The unloading station 122d shown in FIG. 16 includes a unloading conveyor 226 and a tray pusher 228. The tray 155 of the platform 124 is pushed upward at an appropriate time by the cylinder 230 of the pusher 228. Thereafter, the tray is pushed laterally by the slider 232 to which power is transmitted by the cylinder 234. As shown in FIG. 13, the tray is pushed onto the conveyor 226.

The machine generally operates as follows. Initially, a number of trays 155 are configured on the conveyor 150 of the tray loading assembly 142. As shown in Figs. 8 and 9, the braking bars 154 and 158 are operated to configure a plurality of trays in two rows of four. The tray is originally allowed to impinge on the braking bar 158, whereby the tray slides against the rotating conveyor 150. Then, the trays in the second row collide against and contact the trays in the first row from behind.

As shown in FIGS. 10 and 11, the second braking bar 158 is lowered at an appropriate time to allow the tray of the first row to pass over the bed 164. Thereafter, each bed 164 is lowered so that each tray 155 is retained in the slot 126 of the platform 124.

After the passage of time passes, platform 124 rotates 90 ° to station 122b. Thereafter, the braking bar 158 operates to load the second row of trays 155 into the subsequent platform 124 rotated from station 122d into station 122a. Platform 124 rotates from station 122b to station 122c shown in FIG. 6.

As shown in FIGS. 12 and 13, in the tool assembly 144, the platform 124 is lifted from its support 172 between the upper chamber 147 and the lower chamber 149 of the assembly 144. maintain. The alignment pins 178 engage with the coupling holes 182 in the platform 124 to accurately align them. The tapered portion on pin 178 and hole 182 interacts to guide the platform into the desired portion within the station. In this way, the tray 155 is correctly positioned with respect to the tool assembly.

After placing the platform 124 in place, a vacuum is introduced into the upper chamber 147 through the gas exchange passage 232. This is possible because the upper chamber 147 is hermetically engaged with the membrane 192 through the O-ring seal 184. After introduction of the vacuum state into the upper chamber 147, the vacuum state is introduced into the lower chamber 149 through the vacuum tube 239. This is possible because the lower chamber 149 is hermetically engaged with the platform 124 relative to the upper chamber 147 via the O-ring seal 184.

As a result, good fluid communication with the outside of the tray 155 can be achieved under the thin film 192 because of the vacuum in the upper chamber 147 due to the slot 250 in the bottom of the groove 212 of the platform. This is because the air is discharged out of the opening 230 in the tray 155 through the series of holes on the slit to lift the membrane 192. The process proceeds more quickly by providing a filler 234.

After introducing the vacuum, the desired atmosphere is pumped into the tray through openings 257 and 236 in gas pipe 237. This atmosphere is preferably reduced in oxygen content in order to extend the shelf life of the packaged food.

As shown in FIG. 15, the sealing machine 186 may be used to heat seal the thin film 192 to the tray 155. This operation may be a conventional heat sealing operation. The sealing machine 186 reciprocates downward under the control of the brake 202 in response to the change in the fluid pressure in the chamber 203.

After the thin film 192 is sealed in the tray 155, the thin film is cut by the cutter 188. The cutter 188 reciprocates downward to cut the thin film 192 and eventually enters the groove 212. Hydraulic movement of the chamber 217 controls the movement of the cutter 188. In this way, the desired atmosphere can be sealed in the packaging container. Of course, other gas exchange techniques may also be used. The atmosphere inside the assembly 144 preferably reduces the oxygen content to extend the shelf life of the food.

Ambient heat in the assembly 144 that is greatly increased by the heat generated due to the heat sealing operation can adversely affect the operation of the cutter 188. This heat causes the cutting blade to twist and lose accuracy. For this reason, a cooling fluid source, such as water, is circulated through the passage 218 to cool the cutter 188.

After completing the operation, the upper chamber 147 and the lower chamber 149 are moved away and the rolls 196 and 194 are advanced to place a new section of thin film in a position between the chambers 147 and 149. Thereafter, the tray 155 is advanced to the next station 126d.

As shown in FIG. 16, at station 122d, tray 155 is disposed above tray pusher 228 and cylinder 230. At the appropriate time, as shown in FIG. 17, cylinder 230 and pusher 228 are operated to push one or more trays 155 upwards. Thereafter, as shown in FIG. 18, the tray 232 and its cylinder 234 can push the tray laterally. The tray is then taken out by the unloading conveyor 226 from the rotary conveyor.

The entire work is easily carried out by the rotational arrangement of the station 122. The operation of the conveyor is carried out continuously because the conveyor is installed in the rotary batch. In this way, problems arising from the need to return the platform to the initial position of the end of the linear conveyor can be eliminated.

In addition, in the rotational arrangement the central region can be occupied by suitably arranged surge tanks 138. This tank provides a hydraulic source for various operations in the surrounding rotary feeder. Tank 138 is normally closed at both ends by cap 254. As shown in FIG. 19, an outlet 252 is provided at the bottom of the surge tank 138 to discharge the sterilization solution. The outlet can be closed by a removable cover 256. The interior of the tank 138 can be washed with bacteriostatic fluid to minimize the bacteria brought into the packaging container. The tank 138 also provides support for the drive device 132 and the rotary ring 130.

In addition, any particular station may be easily accessible for removal from the rest of the machine due to the conveyor being placed in rotation. Any particular station can be easily replaced with a more suitable station for any particular operation. Also, the failed device can be replaced with a normal operating device. Due to this rotating structure, it is easy to access individual stations for repair.

In addition, repair and replacement are facilitated by installing various connections of the station for the removable power source and fluid source. Furthermore, by installing attachment means of a specific device in each of the instantaneous detachable stations, it is possible to change the station quickly, so that the mechanical device can be switched to another use or the damaged part can be replaced.

As shown in FIG. 20, the packaging process for packaging large meat product 'A' comprises steps a, b and c. In step a, food 'A' is shown contained in a dish-shaped plastic package portion 310 supported by a circumferential flange 312 on the member 314.

This packaging portion 310 may be formed from a variety of conventional materials, including known plastic packaging. In many cases, it may be desirable to form the lower packaging portion 310 from molded foamed plastic so that the packaging portion is relatively rigid.

In step b shown in FIG. 20, the upper packaging portion 318 is shown spaced from the lower packaging portion 310 over the food 'A'. The packaging portion 318 has a hemispherical shape and includes a circumferential flange 320. Similar to the lower packaging portion 310, the upper packaging portion 318 may be made of a conventional plastic material. However, in many cases, it is desirable to form the upper packaging portion 318 from a relatively rigid molded transparent plastic material. This allows food 'A' to be revealed in the package. Both parts 310, 318 are advantageously preformed from a relatively rigid molded plastic material.

In step C shown in FIG. 20, the upper and lower pavement portions 318, 310 compress the flange 320 of the pavement portion 318 over the flange 312 of the pavement portion 310 ( 322 may be joined together along the circumferential flanges 320, 312. If desired, the device 322 may be a heat sealing machine that heat seals the flange portions that are abutted side by side to bond the components thereof.

An advantage of keeping the hemispherical top packaging portion 318 spaced side by side with the bottom packaging portion 310 is that it can convert the gas atmosphere in the packaging container prior to the sealing step C shown in FIG. For example, the air in the packaging container is discharged and the desired gas can be supplied to the position. The desired gas may be oxygen, which is of low oxygen content, thus extending the shelf life of the food. For example, the gas may have a relatively higher carbon dioxide and / or nitrogen content than conventional atmospheric air to prevent or reduce the oxidative action that would shorten the life of meat product 'A'.

As shown in FIG. 21, the lower pavement portion 310 may be maintained in a desired arrangement by two pairs of opposing guides 324. Each of the guides 324 is arranged almost tangential to the bent side of the lower wrap portion 310 to abut the sealing region 326. This sealing area 326 provides an attachment point for the upper packaging portion 318. As can be seen from FIG. 21, the lower wrap portion 310 may include a flange portion 328 that extends outward over one of its two ends. Although the packaging portion 310 is shown in an oval shape in FIG. 21, the cross section may take one of various forms.

FIG. 22 shows that the upper packaging portion 318 is positioned above the lower packaging portion 310. Upper pavement portion 318 includes a pair of blunt end opposing end flanges 334, the end flanges interacting with each guide 324 to be constrained between each set of guides 324. Because the outwardly extending flange portion 334 extends over the tube 330, the tube 330 does not normally guide the upper packaging portion 318 to be positioned in the horizontal plane. This is substantially accomplished by the guide 324. In region 336, there is an area where flange 334 spans over lower pavement 310 because flange 334 extends beyond edge 332 of flange 328.

FIG. 23 shows a packaging machine for performing the packaging operation shown in FIG. 20. For the purpose of showing that various packaging shapes may be used, the packaging container 338 shown in FIG. 23 has a slightly different shape than that shown in FIG. 20. In particular, the lower pavement portion 310 is deeper than the pavement portion 310 shown in FIG. 20, and the degree of inclination of both the lower and upper pavement portions 318, 310 is shown in FIG. 20. Greater than

The lower pavement portion 310 is disposed within a tray 340 of a corresponding shape, which is consistent with the outer shape of the lower pavement portion and supports the flange 312. The upper packaging portion 318 has a flange 336 overlying the filling tube 330.

The filling tube 330 reciprocates up and down along the slot 342. However, the maximum extension size upward is controlled by the protruding edges 344 of the adjacent guide 324. Each tube 330 includes an outer cylinder 330a and an inner cylinder 330b.

Outer cylinder 330a includes a set of '0' rings 346 to prevent leakage around tube 330. Fins 348 are provided to control the degree of downward movement of tube 330 and to prevent rotation of the tube about the longitudinal axis of the tube. A bore 350 is formed at the center of the tube 330, which allows gas to enter and exit the interior of the packaging container or the passage 352. Accordingly, the gas may enter and exit the inside of the packaging container having the shape shown in FIG. 23 through the passage 352.

The compressed gas supply passage 372 is connected to a compressed gas supply source (not shown). If desired, compressed gas may be communicated through passage 372 to act on the lower end of outer cylinder 330a. This causes the tube 330 to move to the upper position shown in FIG.

A push bar 354 and a sealing bar 356 are disposed side by side above the upper packaging portion 318. The seal bar 356 may be a conventional heat seal bar that heat seals the flange of the upper wrap portion 318 to the flange of the lower wrap portion 310.

The vacuum chamber cover 390 is sealed to the lower chamber 392 through the contacts of the inner and outer circumferential seals 394, 396 and the gasket 398 on the lower chamber 392. The valved passage 400 is provided for suction forming a vacuum into the chamber formed by the cover 390.

FIG. 25 illustrates another embodiment in which a gas exchange system is formed in the upper packaging portion 318. Gas exchange section 358 is generally configured as described above. The exchange portion 358 includes one or more holes 360 formed in the packaging portion 318. These holes are covered by a circular first plastic thin film layer 362 through which atmospheric air can permeate. This layer 362 is sealed to the packaging portion 318 at location 364. A fluid impermeable upper plastic thin film layer 366 sealed at the top packaging portion 318 at position 368 is attached over the thin film layer 362. If desired, the thin film layer 366 may be peeled off for gas exchange between the lower thin film layer 362 through the hole 360.

The method and apparatus according to the present invention may be implemented in the following forms. The lower pavement portion 310 loaded into the tray 340 of the shape mating type is supported by its flange 312. Then, if not already loaded meat product 'A' may be loaded into the packaging 310. A relatively rigid top or top portion 318 is then arranged on top of the fill tube 330 as shown in FIG. 23 while being aligned over the bottom wrap portion 310.

Initially, air in the packaging container exits the passage 352 through the passage 400 and the bore 350. The passage 400 is then closed and the desired gaseous atmosphere is passed through the passage 352 and the bore 350 into the packaging container. This gaseous atmosphere may be an atmosphere having a relatively low oxygen concentration and a relatively high atmosphere for carbon dioxide and / or nitrogen content (ie, for normal atmospheric air). This atmosphere extends the shelf life of meat products. This is because the aging and discoloration of meat products is caused by oxygen.

Once the desired atmosphere is established, the push bar 354 pushes the gas filling tube 330 downward in the passage 342 until the tops of the fins 348 and the slots 380 contact each other. In this position (shown in FIG. 24), the upper packaging portion 318 abuts the lower packaging portion 310. At this point, the sealing area 326 similarly abuts. The packaging container is then sealed along the sealing area 326 of the upper and lower packaging portions 310, 318 to ensure a hermetic sealing between the two packaging portions. This is accomplished through the sealing bar 356, which can heat seal the components together with one another in one advantageous embodiment. The sealing bar 356 reciprocates with the push bar 354. However, push bar 354 pushes tube 330 down the flange so that tube 330 does not interfere with the sealing operation, regardless of the thickness of the packaging container.

The completed packaging container 338 is removed by raising the cover 390 using the sealing bar 356 and the push bar 354. The packaging container 338 may be removed from the carrier 340 of the conformal shape. This can be done as a batch or continuous operation, if desired.

Once the gas tube 330 has been reciprocated to the upper position, the operation can be repeated. This is done by supplying air pressure to the upper cylinder 330a. Air pressure is released through a relief valve (not shown) when the tube 330 is pushed down by the push bar 354.

The positioning of the upper and lower packaging portions 310, 318 relative to each other allows the guide 324 and filling tube 330 to interact with a special packaging shape to ensure that these portions are precisely next to each other. Is guaranteed by the installation. Moreover, the flange 336 of the upper packaging portion 318 keeps the packaging container separated when the packaging portions abut the filling tube 330.

First, the lower packaging portion 310 is guided by the tube 330 and the guide 324 and inserted into the shape mating carrier 340. The upper packaging portion 318 is then positioned by the guide 324 and placed on the tube 330. Thereafter, the cover 390 can be closed and the process repeated.

For many applications, especially red meats, it may be desirable to exhaust the low oxygen atmosphere in the container at the point of sale. Otherwise, the color of the meat will be mauve by a packaging container with a low oxygen atmosphere. Therefore, in the supermarket, the upper fluid impermeable thin film 366 may be peeled off. This causes the air to get into the packaging, making the meat red.

Protrusions 336 of the upper packaging portion 318 are provided above the lower packaging portion 310 to facilitate removal of the hemispherical upper packaging portion 318 in use. Moreover, the concealed position of the protrusion 336 minimizes the possibility of accidental opening.

Accordingly, the present invention provides a packaging container, a packaging method, and a packaging apparatus that meet these objects and the aforementioned advantages. Although the invention has been described in terms of specific embodiments, it will be apparent to those skilled in the art that many modifications and variations are possible in light of the above teaching. Accordingly, it is intended that the present invention cover such embodiments, modifications and variations that fall within the spirit and broad scope of the appended claims.

Claims (10)

As a packaging container, With a tray, A flexible first thin film sealed to the tray, A flexible second thin film sealed to the tray over the first thin film, Wherein the first and second thin films are fixed at separate locations on the tray to form substantially the same plane with respect to each other, and the second thin film is removable from the tray independently of the first thin film. Vessel. The packaging container according to claim 1, wherein the tray includes a circumferential flange having a lip and a concave lip surrounding the ledge to secure the first and second thin films, respectively. The method of claim 1, Wherein said tray comprises a pair of substantially identical planar sealing ledges for securing said first and second thin films. The method of claim 1, The second thin film packaging container, characterized in that the gas permeability is lower than the first thin film. The method of claim 1, And the first and second thin films are made of an elastic material. The method of claim 1, Wherein said first and second thin films are made of a substantially impermeable material. The method of claim 1, Wherein said tray is made of a foamable material and the ledge is pressed to a substantially uniform thickness. The method of claim 1, Wherein said first and second thin films are connected only through said tray. The method of claim 1, A pair of sealing surfaces for accommodating the first and second thin films, wherein a recess is provided between the sealing surfaces to facilitate separation of the first thin film from the web in place on a tray during the manufacture of a packaging container. Characterized by a packaging container. The method of claim 1, And the second thin film is peelable from the tray.