Packaging Machine For Vacuum Skin Packaging
A vacuum-skin packaging machine for sealing film onto a tray containing a product includes a vacuum system. The vacuum system includes a vacuum pump, piping, and valves. The machine includes a top structure and a bottom structure defining a vacuum chamber in communication with the vacuum pump via the piping. An actuating mechanism transitions the top structure and the bottom structure between an opened state where they are separated and a closed state where they are sealed. A platen-movement mechanism moves a platen to the chamber while the top and bottom structures are in the opened state. The platen holds the trays. A heating plate heats the film while the top and bottom structures are in the closed position. The heated film is forced against the trays in response to a valve venting a region of the vacuum chamber adjacent to the heated film.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/008,863 titled “Packaging Machine For Vacuum Skin Packaging,” filed Jun. 6, 2014, which is incorporated herein by reference in its respective entirety.
COPYRIGHTA portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTIONThe present invention relates generally to a packaging apparatus and methods and, more particularly, to a packaging machine for use in a vacuum-skin packaging process.
BACKGROUND OF THE INVENTIONOne common packaging format for fresh meat that is cut at a retail store is PVC-wrapped foam tray. The clear PVC film is very permeable to oxygen and allows the meat to maintain the preferred red color for 3-5 days. After packaging, the color deteriorates until it becomes unsalable.
Today, most fresh meat is cut and packaged at a centrally located factory in a different type of packaging format that protects the color for a longer time because more than 5 days are required to properly distribute the product. Further, most retailers want a color life for the meat that extends for more than a week after they receive it in order to reduce discounts and losses. This form of packaging is termed “case ready.” As the name implies, the case-ready packaging format involves fabricating and packaging the finished retail cut so as to make it ready for the display case, even to the point of pricing and/or labeling with UPC codes to make inventory control easy for the retailer to which it will be shipped.
Because fresh meat typically deteriorates quickly after cutting and exposing the meat surface to atmospheric oxygen, case-ready packaging formats have been designed to delay this deterioration. The case-ready package is called upon to extend the consumer preferred color for more than 14 days, which is typically enough time to distribute the product and display for retail sale. Most of these case-ready packaging formats use machines that eliminate oxygen in order to protect color and delay bacterial spoilage.
A common approach to eliminate oxygen is to modify the atmosphere surrounding the meat within the package. The typical modified atmosphere package (MAP) is formed on equipment using pre-formed trays and rollstock film for lidding. The gas inside the package is modified with nitrogen, carbon monoxide, carbon dioxide and/or oxygen at controlled levels found to be effective at extending shelf life of the specific food article being packaged. The equipment function involves indexing filled preformed trays into a vacuum chamber where the atmosphere is sucked out of the chamber. The rollstock film is indexed into the chamber at the same time and heated during evacuation. The modified gas of choice is vented into the chamber before a seal plate compresses the film onto the preformed tray flange to hermetically seal it to the tray, thereby creating the package that is then trimmed apart from adjacent packages using a cutting system. The film stays with the trays as they are cut and then rolled onto a take-up roller to remove scrap generated by the cutting action. As such, a “MAP” packaging format involves a gas that is actively flushed into the headspace of a hermetically sealed package.
Another common case-ready packaging format employs a master package comprised of flexible film. The master package is flushed with an oxygen-free atmosphere that contains carbon monoxide. Several PVC wrapped trays with meat are contained within the master package. Since the PVC film is gas permeable, the carbon monoxide gas causes the meat to bloom to the consumer preferred red color. Usually, six to eight trays are packed into a preformed bag or pouch at the regional facility where snorkel equipment is used to modify the atmosphere and hermetically seal the bag or pouch. Shelf life can be extended to upwards of 30 days. However, the color of the meat becomes unacceptable in only 3-5 days after removal from its master package.
Another approach is vacuum packaging with flexible films on horizontal form fill seal machines (HFFS machines). They employ two rolls of flexible film. One is referred to as the top or non-forming film and the other as the bottom or forming film. The bottom film is generally formed into a size and shape that accepts the meat article to be packaged. The formed film pocket is covered with the top film as it indexes into an evacuation chamber. The machine evacuates air from inside the package and then hermetically seals the top non-forming film to the bottom forming film to create the package. Upon venting, the packaging material collapses around the product. The absence of oxygen slows down the oxidation that causes rancidity. The product's quality and freshness does not degrade during frozen storage. Products in a vacuum package can be stored in the freezer for greater than six months.
A vacuum skin package (VSP) is a type of vacuum packaging where the top film is heated and formed around the article to be packaged. In a VSP machine, one object is to form the film uniformly to the shape of the food article and seal it to the tray. The end result is a film that conforms to the product without wrinkles or weak spots and a film to tray seal that is continuous up to the edge of the product. The tray acts as a bottom support member for the product. As such, a VSP packaging format uses a flexible film that is heated and formed over the top of a package in a manner that conforms to the shape of the product. It thereby forms an invisible skin to enhance product appearance. The present invention is directed to improvements to a vacuum-skin packaging machine.
SUMMARY OF THE INVENTIONAccording to a first aspect of the invention, a method for providing a vacuum-skin packaging (VSP) for products on trays uses a vacuum chamber defined by a top structure and a bottom structure. The method includes (i) while the bottom structure is retracted away from the top structure, automatically moving a platen along a path that extends into the vacuum chamber, the platen containing one or more of the trays; (ii) positioning a film over the platen; (iii) after the platen is positioned within the vacuum chamber, moving the bottom structure upwardly against the top structure so as to form a seal between the top structure and the bottom structure; (iv) creating a vacuum within the vacuum chamber, the film dividing the vacuum chamber into an upper volume and a lower volume; (v) heating the film; (vi) venting the upper volume above the platen to force the heated film onto the platen and the one or more tray; (vii) retracting the bottom structure from the top structure of the vacuum chamber; and (viii) automatically moving platen along the path out of the vacuum chamber.
According to another aspect of the invention, a vacuum-skin packaging machine for sealing film onto a tray containing a product includes a vacuum system. The vacuum system includes a vacuum pump, piping, and valves. The machine further includes a top structure and a bottom structure defining a vacuum chamber. The chamber is in communication with the vacuum pump via the piping. An actuating mechanism transitions the top structure and the bottom structure between (i) an opened state whereby the top structure and the bottom structure are separated and (ii) a closed state whereby the top structure and the bottom structure are sealed together. A first platen-movement mechanism moves a platen from an in-feed position into the chamber while the top structure and bottom structure are in the opened state. The platen holds the trays. A heating plate heats the film while the top structure and bottom structure are in the closed position. The heated film is forced against the platen and the trays in response to one or more of the valves venting a region of the vacuum chamber adjacent to the heated film.
In yet another aspect of the invention, a vacuum-skin packaging machine for sealing film onto a tray containing a product comprises a vacuum system. The vacuum system includes a vacuum pump, piping, and valves. The machine includes a top structure and a bottom structure defining a vacuum chamber. The top structure and the bottom structure is transitionable between (i) an opened state whereby the top structure and the bottom structure are separated and (ii) a closed state whereby the top structure and the bottom structure are sealed together to create the vacuum chamber. A moveable platen is located within the vacuum chamber. The movable platen holds the tray. A stationary heated plate is located within the top structure. The stationary heating plate heats the film while the top structure and bottom structure are in the closed state. The heated film is forced against the platen and the tray in response to one or more of the valves venting a region of the vacuum chamber adjacent to the heated film.
In yet another aspect of the invention, a packaging machine for vacuum sealing a film onto a tray containing a product comprises a housing and a vacuum system located within the housing. The vacuum system includes a vacuum pump, piping, and valves. The machine includes a top structure and a bottom structure defining a chamber. The top structure and the bottom structure is transitionable between (i) an opened state whereby the top structure and the bottom structure are separated and platens can enter and exit the chamber and (ii) a closed state whereby the top structure and the bottom structure are sealed together to create a vacuum chamber. The machine includes a continuous platen-movement path on which the platens move from a loading station where trays are loaded on the platens, into the vacuum chamber where the film is sealed against the trays, to a removal station where the filmed trays are removed from the platens, and back to the loading station.
In a further aspect, the invention is a method of vacuum-skim packaging that includes automatically moving a plurality of platens along a continuous path from a loading station where the trays are loaded on the platens, to the vacuum chamber where the film is sealed against the trays, to a removal station where the filmed trays are removed from the platens, and back to the loading station. Each of the platens contains one or more of the trays. Each of the platens receives a heated film while in the vacuum chamber.
In a further aspect, the present invention is a platen for receiving trays with product. The platen comprises a main body and a plurality of polymeric inserts. The main body includes a plurality of tray-receiving regions and a plurality of grooves that are located around the plurality of tray-receiving regions. The plurality of polymeric inserts is located within the plurality of grooves. The plurality of polymeric inserts is positioned to contact a film that is placed over the product and the tray. The plurality of polymeric inserts engage cutting mechanisms that cut the film around the trays. Preferably, the platens are a metal, such as aluminum, and the polymeric inserts are nylon.
Additional aspects of the invention will be apparent to those of ordinary skill in the art in view of the detailed description of various embodiments, which is made with reference to the drawings, a brief description of which is provided below.
While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTIONWhile this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. For purposes of the present detailed description, the singular includes the plural and vice versa (unless specifically disclaimed); the words “and” and “or” shall be both conjunctive and disjunctive; the word “all” means “any and all”; the word “any” means “any and all”; and the word “including” means “including without limitation.”
As show in
One or more evacuation pumps 40 may be used to pull the vacuum within the vacuum chamber 30. Because the film located above the platen 14 divides the vacuum chamber 30 into a lower volume and upper volume, lower piping 42 is connected to the evacuation pump 40 to remove the air from the lower volume located below the film (i.e. the region surrounding the platen 14 which holds the trays 16 and the product 18). The lower piping 42 includes internal air conduits within the pair of elongated support members 37 that support the stationary platform 36. The elongated support members 37 and/or the stationary platform have openings to permit the evacuation and the venting of the lower volume below the film. And, upper piping 44 (only a portion of which is shown) is connected to the evacuation pump 40 to remove air from the upper volume located above the film. Because the upper volume is smaller, obtaining a vacuum is easier in the upper volume than the lower volume. Valves are positioned within the lower piping 42 and upper piping 44 to initiate the evacuation, and to release the evacuation.
The film from the web 20 is advanced over one or more rollers 50 before entering the region of the vacuum chamber 30 when the bottom structure 32 is in its retracted position away from the top structure 34. A film-advancing mechanism 52, which may include one or more pneumatically activated pistons, grabs the film in a region adjacent to the roller 50 and pulls it across the vacuum chamber 30. A cutting mechanism 54, which includes one or more knives, cuts the film in the region adjacent to the roller 50, which is outside the vacuum chamber 30, such that the platen 14 and the trays 16 can be removed from the opposing side of the VSP machine 10 once the packaging process has been complete. The cutting mechanism 54 preferably cuts the film when the bottom structure 32 and the top structure 34 are engaging each other to form the enclosed vacuum chamber. The cutting mechanism 54 can also be pneumatically activated.
Various devices can be used to move the bottom structure 32 of the vacuum chamber 30. In one preferred embodiment, a pneumatically actuated piston 60 forces the bottom structure 32 upwardly against the top structure 34. And, after the packaging process within the vacuum chamber 30 has been completed, the piston 60 permits the bottom structure 32 to be retracted from the top structure 34. The bottom structure 32 of the vacuum chamber 30 includes two openings with sealing structures (such as O-rings) that engage the pair of elongated support members 37 when the bottom structure is moving between the opened state and the closed state.
To remove the filmed platen 14c from the machine 10, a power driven roller 62 grabs the underside of the platen 14 and advances it away from the machine 10. The film, which has been sealed to each of the four trays 16 may be cut automatically, or manually, on the platen 14. The platen 14 may be designed with grooves to receive the cutting edges of the tools used to separate the sealed film into four distinct pieces that cover the four trays 14, respectively. Excess film is then removed and discarded.
As will be discussed below with respect to
In summary, the present invention involves the platen 14 that is tooled to receive at least one, and preferably several (such as four or more) preformed trays 16 having a unique shape. The platen 14 is used to transport the trays 16 containing products (e.g., freshly cut meat) into and out of the vacuum chamber 30. One platen 14 can hold several trays as it is indexed onto the stationary platform 36 within the vacuum chamber 30. The bottom structure 32 of the evacuation box moves upward to surround the platen 14 and, in combination with top structure 34, forms the vacuum chamber 30 that encloses the platen 14.
To seal the film to the trays 16, after chamber 30 is evacuated, it is vented first from the upper volume within the top structure 34 adjacent to the heating plate 38 that is used to heat a film located over the trays 14 within the vacuum chamber 30. The venting of the upper volume of the chamber 30 collapses the heated film onto the platen 14 with the trays 16 holding the product 18. The venting of the lower volume below the film within the bottom structure 32 then occurs, and the film web is cut by the cutting mechanism 54 so that when the bottom structure 32 of the vacuum chamber 20 retracts to open the chamber 30, the film stays with the tray-holding platen 14 at a level several inches below the film's original in-feed position. The now-filmed platen 14 is removed from the chamber 30 and transferred to another station for film cutting, before removing the trays 16 from the platen 14. Multiple platens 14 may be used to facilitate the machine functions that are required to create a vacuum skin package and increase production capacity.
In
In
In summary, the machine 10 provides for a manufacturing method of a vacuum skin package where the skin packaging film is heated and formed over the product 18 as it sits on a flat preformed tray 16. The platen 14, which is tooled to the shape of the preformed tray 16, is used to transport the tray 16 into and out of the vacuum chamber 30. After loading a platen 14 containing the trays 16 onto the in-feed table 70. The pneumatic slide element 72 (or a piston) pulls the platen 14 onto the stationary platform 36. At the same time, a pneumatic slide or piston of the film-advancement mechanism 52 pulls the film into the chamber 30 just below the heating plate 38, which is housed within the top structure 34 of the evacuation chamber 30. After the film and platen 14 are in place, the bottom structure 32 of the evacuation chamber 30 is pushed upward to surround the platen 14 and the evacuation chamber 30 is closed. The chamber 30 is evacuated with a vacuum pump 40 by opening bottom and top evacuation valves within the lower piping 42 and the upper piping 44. The upper volume (within the top structure 34) of the evacuation chamber 30 above the film is more rapidly evacuated due to its smaller volume and the film sucks tightly to the perforated heating plate 38. After chamber evacuation and film heating, the upper volume (within the top structure 34) of the chamber 30 above the film is vented prior to venting the lower volume below the film. The venting forces the heated film onto the trays 16 being held by the platen 14. The film web is cut with a piston-powered knife 54 so that when the bottom portion 32 retracts to open the chamber 30, the film stays with the tray-holding platen 14 several inches below the in-feed film web line. The filmed platen 14c is removed from the chamber when the pneumatic slide element 72 piston pulls another non-filmed platen 14a onto the stationary platform 36. The non-filmed platen 14a entering the chamber 30 pushes the filmed platen 14c onto a power-driven roller 62. The filmed platen 14c is then free to be fed into another separate machine for film cutting before removing the trays 16 from the platen 14. By use of multiple platens 14, increased production capacity can be achieved.
In
To move the platens 114, a pair of transfer elements 180 moves the platens 114 along at least a portion of the path. In one preferred embodiment, the pair of transfer elements 180 simultaneously move in the same direction. For example, a first transfer element 180a moves back from the position in
While
As shown in
In
As shown in
One of the benefits of the present invention is that the machines 10, 110 can receive different platens that are configured to receive different styles and shapes of trays. Accordingly, the first platen may have two large trays with a first type of product, but a second platen processed immediately thereafter may have eight small trays with different types of products. As long as the platen has exterior dimensions to be automatically transferred along the generally horizontal linear path of the machine 10 or the continuous cyclical path of the machine 110, its interior structures that hold the platens may be different. Furthermore, the present invention contemplates that the machine 10 and the machine 110 may utilize the same style platen, such that the platen design itself is modular in an array of different vacuum skin packaging machines.
Preferably, the platen 214 is made from a metal, preferably aluminum, and each of the grooves 220 is fitted with an insert 225. The insert 225 is preferably a polymeric material, such as nylon. When the insert 225 is a polymeric material (preferably nylon), the film that is being heated in the vacuum chamber is held nicely against the insert during the cutting process. The insert 225 also serves the function of receiving the cutting mechanism and yielding to the cutting mechanism such that the sharp edges associated with the cutting mechanism is less prone to becoming dull during repetitive use. Moreover, if the inserts 225 become worn or contaminated after repetitive use, they can easily be replaced in the grooves 220 of the platen 214. Furthermore, the use of the metal (such as aluminum) for the platen 214 is beneficial in that it does not warp under the stresses and heat encountered throughout the packaging process described above. However, it should be noted that the present invention contemplates that the platen 214 can be made of other materials, such as rigid plastics, that are encounter less warp produced by heat and stress.
The platen 214 may have adjustable walls that are movable by screw mechanisms to accommodate various sizes and/or shapes of the trays. Alternatively, the internal structure of the platen 214 that defines the tray-receiving regions is removable and/or replaceable with other various shaped internal structures to accommodate various sizes and/or shapes of the trays.
Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and aspects.
Claims
1. A method for providing a vacuum-skin packaging for products on trays using a vacuum chamber defined by a top structure and a bottom structure, comprising:
- while the bottom structure is retracted away from the top structure, automatically moving a platen along a path that extends into the vacuum chamber, the platen holding one or more of the trays;
- positioning a film over the platen;
- after the platen is positioned within the vacuum chamber, moving the bottom structure upwardly against the top structure so as to form a seal between the top structure and the bottom structure;
- creating a vacuum within the vacuum chamber, the film dividing the vacuum chamber into an upper volume and a lower volume;
- heating the film;
- venting the upper volume above the platen to force the heated film onto the platen and the one or more trays;
- retracting the bottom structure from the top structure of the vacuum chamber; and
- after the retracting, automatically moving the platen along the path out of the vacuum chamber.
2. The method of claim 1, wherein the automatic moving of the platen along the path into or out of the vacuum chamber is in response to activating at least one of a power-driven roller or a power-driven slide element.
3. The method of claim 1, wherein the automatic moving of the platen along the path out of the vacuum chamber is in response to a second platen engaging the platen as the second platen enters the vacuum chamber.
4. The method of claim 1, wherein the heating the film occurs by use of a heating plate located within the upper structure adjacent to the film.
5. The method of claim 1, wherein the positioning the film occurs though an automated film-feeding mechanism that pulls the film from a web into the vacuum chamber in a direction that is generally parallel to the path of the platen.
6. The method of claim 1, wherein the platen holds a plurality of the trays, and the method further includes cutting the film in multiple directions with a plurality of knives to create individual packaged trays that can be independently removed from the platen.
7. The method of claim 1, wherein the platen is held within the vacuum chamber via a stationary platform located within the bottom structure, the stationary platform being supported by at least one elongated support member, the bottom structure includes at least one opening for receiving the at least one elongated support member.
8. The method of claim 7, wherein the at least one elongated support member includes an internal air conduit that is used to for creating the vacuum within the low volume.
9. The method of claim 1, further including, after the trays have been removed from the platen after exiting the vacuum chamber, transferring the platen along a path that returns the platen to an entry point where non-filmed trays can be loaded on the platen and the platen can re-enter vacuum chamber.
10. The method of claim 1, further including venting the lower volume after the venting of the upper volume.
11. A vacuum-skin packaging machine for sealing film onto a tray containing a product, comprising:
- a vacuum system including a vacuum pump, piping, and valves;
- a top structure and a bottom structure defining a chamber, the chamber being in communication with the vacuum pump via the piping;
- an actuating mechanism to transition the top structure and the bottom structure between (i) an opened state whereby the top structure and the bottom structure are separated and (ii) a closed state whereby the top structure and the bottom structure are sealed together; and
- a first platen-movement mechanism to automatically move a platen from an in-feed position to within the chamber while the top structure and bottom structure are in the opened state, the platen holding the tray; and
- a heating plate to heat the film while the top structure and bottom structure are in the closed position, the heated film being forced against the platen and the tray in response to one or more of the valves venting a region of the chamber adjacent to the heated film.
12. The vacuum-skin packaging machine of claim 11, further including a second platen-moving mechanism to automatically move the platen from the chamber after receiving the heated film.
13. The vacuum-skin packaging machine of claim 11, further including an automatic film-feeding mechanism to move the film into the chamber when the top structure and the bottom structure are in the opened state.
14. The vacuum-skin packaging machine of claim 13, further including an automatic film-cutting mechanism outside the chamber to cut the film after the top structure and the bottom structure are in the closed state.
15. The vacuum-skin packaging machine of claim 11, further including a cutting station along the path outside the chamber, the cutting station automatically cutting the film that is attached to the trays on the platen in multiple directions with a plurality of knives.
16. The vacuum-skin packaging machine of claim 11, further including platen-support structures to define a continuous platen-movement path on which the platens move from a loading station where trays are loaded on the platen, then to the chamber where the film is sealed against the trays, then to a removal station where the filmed trays are removed from the platens, and then back to the loading station.
17. The vacuum-skin packaging machine of claim 16, further including platen-moving mechanisms that automatically move the platens around the continuous platen-movement path.
18. A vacuum-skin packaging machine for sealing film onto a tray containing a product, comprising:
- a vacuum system including a vacuum pump, piping, and valves;
- a top structure and a bottom structure defining a chamber, the top structure and the bottom structure being transitionable between (i) an opened position whereby the top structure and the bottom structure are separated and platens can enter and exit the chamber and (ii) a closed position whereby the top structure and the bottom structure are sealed together to create a vacuum chamber in which heat is applied to the film to attach the film to the trays on the platens; and
- a continuous platen-movement path on which the platens move from a loading station where trays are loaded on the platen, into the vacuum chamber where the film is sealed against the trays, to a removal station where the filmed trays are removed from the platens, and back to the loading station.
19. The vacuum-skin packaging machine of claim 18, wherein the continuous platen-movement path further includes one or more cutting station located after the vacuum chamber and before the removal station, the cutting station automatically cutting the film in multiple directions with a plurality of knives.
20. The vacuum-skin packaging machine of claim 18, further including a vacuum system including a vacuum pump, a first set of piping, and a second set of piping, the first set of piping being in communication with an upper volume located above the film within the vacuum chamber, the second set of piping being in communication with a lower volume located below the film within the vacuum chamber
Type: Application
Filed: Jun 3, 2015
Publication Date: Dec 10, 2015
Inventors: Dan G. Siegel (Belleville, IL), Thomas H. Wuller (Belleville, IL)
Application Number: 14/730,014