CN1191202A - Method and apparatus for forming and hermetically sealing sheet-like food products - Google Patents

Abstract

An apparatus for palletizing sheets of products of a single sheet shape on at least one palletizing station, an endless belt having a plurality of small holes; a drum device for moving the belt; for holding products along the belt in its Vacuum device (78) on the upper; the air injector that can effectively provide positive air pressure, which is located at the beginning of a palletizing station, and the positive air pressure can peel the product from the belt and drop it at the palletizing station . The palletizing station includes an intermediate single piece receiving device having a plurality of retractable claw-like members and elevators, and a programmable control or microprocessor operatively connected to a corresponding ejector of each palletizing station to facilitate The number of sheets in each stack is controlled.

Description

Method and apparatus for forming and hermetically sealing sheet-like food products

This application is a divisional application of the pending invention patent application with the same name whose application date is May 11, 1992 and whose application number is CN92104546.8.

The present invention relates to a method and apparatus for packaging food, in particular to an apparatus and process for the packaging and palletizing of hermetically sealed individual pieces of food.

Various methods and apparatuses exist for manufacturing and packaging individual pieces of food such as cheese, and although general apparatus and methods are suitable for packaging individual pieces, they are not without disadvantages.

A typical single-piece package is constructed from a continuous film or film strip of thermoplastic material. The film strip is first folded into a V-fold. The term V-fold here means the shape in which a length of material is folded over itself, thus forming what is hereafter referred to as a front and a back panel, which are joined by folding over their bases, Therefore, its cross-section is approximately in the shape of a letter V. The film strip is typically folded such that the back panel is longer than the front panel so as to define a flap portion on the back panel which extends over the top edge of the front panel. The flap portion is generally folded over the front panel to form a tubular film strip.

After the flaps are folded over the front panel, a tubular membrane is defined. The processed cheese is then added to the tube and the strip of film and cheese is smoothed. Transverse seals are then formed at predetermined intervals along the longitudinal length of the tubular film strip. After the tube has been transversely sealed, it is cut along the transverse seal in order to produce individual packs of cheese. Several methods are currently used for transverse sealing.

In one commonly used method of forming a transverse seal, the transverse seal is formed by applying pressure to a flat film (including the cheese filled therein) at a designated station. This applied pressure causes the cheese to form an ultra-thin layer or film that remains in the transverse seal. An ultra-thin layer or film of cheese acts as an adhesive, sealing the two plastic film strips together. After this "cheese" seal is formed, the film segments are cut to define separate cheese slices.

Although the "cheese" seal provides an adequate seal for each individual cheese slice, the shelf life of the packaged cheese product is not as long as desired. This is due to the fact that the cheese seal is a relatively weak seal, which can be damaged and allows air to enter the cheese slice under normal atmospheric conditions. The cheese slices dry out or become damaged after a short time.

Other methods of lateral side sealing have been disclosed. For example, US Patent No. 4,586,317 to Bussell discloses an apparatus for forming a seal in packaging material, such as processed cheese, which utilizes a sealing unit having a limited number of small grooves on the surface. The packaging film is co-extruded or laminated by including an inner sealing layer having a lower thermoplastic melting temperature and an outer layer which does not melt under sealing conditions. The sealing element heats and pressurizes the tube transversely, thereby sealing the inner layers of the packaging film together. Although the apparatus and method disclosed in this patent provide a suitable transverse seal, the resulting product suffers from the same disadvantages as described above. Since the longitudinal seal is formed by placing a flap on the V-folded film strip and simply folding the flap onto the upper surface of the film with the front panel, only a fragile seal is formed. Air and other gases will thus get inside the packaged slices of cheese, reducing the shelf life of the product.

It is therefore desirable to provide a single slice of cheese wrapped in a package which is hermetically sealed on all sides. To achieve this sealing, it is necessary to seal along the longitudinal edges as well as the transverse edges of the film strip to form an airtight seal. Hermetically sealed packaging has only a few advantages: For example: the hermetically sealed foil allows it to be submerged in a liquid for cooling or sterilization. Further, the hermetically sealed wafers are substantially aseptically packaged.

For economical purposes, it is desirable to provide longitudinal and transverse sealing in continuous operation. However, with many existing common methods, the seal is formed in an intermittent manner. In these common methods, the seal is typically formed by heated jaws that reciprocate between open and closed positions. Sealing When the jaws are closed, they seal the desired portion of the film strip. After sealing the section, the collets retract and the film strip advances to seal the next section. However, this approach has significant disadvantages. The film belt must stop and start continuously according to the reciprocating movement of the chuck. Such an apparatus is disclosed, for example, in US Patent No. 2,460,460 to Langer2.

Another problem encountered in the processing and packaging of cheese slices (and in the packaging of other products packaged into slices) is the lack of a common, simple and effective method of palletizing slices, typically stacking groups of slices involving an operator Or a palletizer for operation. Conventional palletizers, however, do not pack the different stacks of cheese with the required degree of efficiency and precision. It is desirable to provide a palletizing device or method that allows sheets from a single individual packaging machine to be stacked on many different stacks, and it is more desirable to provide a device or method that allows an operator to move from one palletizing station to the next. A station selectively varies the number of sheets in the stack. Preferably, the palletizing device is also capable of accurately stacking sheets onto many different stacks from a relatively fast production line.

Therefore, in view of the above, it is an object of the present invention to provide an apparatus and method for producing a hermetically sealed individual slice of a food product, such as processed cheese.

Another object of the present invention is to provide a method of apparatus for providing a continuous and efficient arrangement for forming a hermetic seal along all sides of the packaging film web.

Yet another object of the present invention is to provide an apparatus and method for stacking a desired number of slices of a food product, such as cheese, into a palletizing station from a high speed packaging system.

To achieve the above and other objects, and in accordance with the use of the present invention, there is provided an apparatus and method for forming hermetically sealed packages of food products in slices. A film strip of thermoplastic material is first formed into a tubular structure with an airtight longitudinal seal. To form the tubular structure, means are provided for folding the continuous film strip of thermoplastic material into a V-folded state, and means are provided for continuously forming an airtight seal along the longitudinal opening edge of the film strip in the V-folded state. device. Form an airtight seal between the front surface of the film strip and the inner surface of the rear surface to define a tubular film strip, then add the cheese that has been formed into a soft mass into the tubular strip, and place the tubular strip The strip is flattened to form a continuous film strip. Means are provided for forming a hermetically sealed transverse seal arranged substantially transverse to the longitudinal direction of advancement of the film strip.

In a preferred embodiment of the invention, the means for forming the longitudinal seal comprises a pair of retaining plates having opposed rocking surfaces. The fixed plate is arranged such that the distance between the rocking surfaces of the plate is predetermined. The fixed plate is heated and the film strip is passed through the space between the two plates. As the film web moves across the plate, the rocking surface alternately presses the front and rear surfaces of the film web into intimate contact with each other, thereby forming an airtight longitudinal seal without pinching the film between the two surfaces .

In another embodiment of the invention, a palletizer is provided for stacking the sheets from the wrapping and cutting machine into a plurality of stacks. The palletizer comprises a conveyor belt with a number of small holes on which slices of cheese are placed. A vacuum system provides vacuum through the holes to keep the cheese slices on the belt. Devices are provided to drive the belts to feed the cheese slices to the palletizing station. The vacuum pressure is sufficient to keep the cheese slices on the belt, even when the slices are placed on the underside of the belt. Set up many palletizing stations in sequence. Each palletizing station includes a device for applying positive air pressure on the leading edges of the cheese slices as the cheese slices on the belt are conveyed adjacent to each palletizing station. As the cheese is conveyed on the belt, this positive air pressure exceeds the vacuum pressure that holds the slices on the belt, thereby peeling the cheese slices off the belt and falling due to gravity to the intended palletizer bit. In a preferred embodiment, a means is provided for selectively engaging and disengaging positive air pressure at the leading edge of each palletizing station. According to this palletizing arrangement, a device is therefore provided for stacking a predetermined number of packaged cheese slices produced with a relatively high yield into a number of stacks.

The present invention's other purposes, advantages and novel features will be partly described in the following description, and the present invention will make the present invention's additional Objects, advantages and novel features will become apparent in part. The objects and advantages of the present invention are achieved by the technical features specified in the claims appended to this specification.

Figure 1 is a schematic diagram of a preferred embodiment of the apparatus and method of the present invention including a longitudinal sealer, a transverse sealer and a palletizer.

Figure 2 shows a preferred embodiment of a slice of cheese (flaps folded on) sealed using the method and apparatus of the present invention.

Figure 3 shows the cheese slice shown in Figure 2 with its flaps unfolded.

Figure 4 shows a preferred embodiment of the longitudinal sealer and leveling device of the present invention.

FIG. 5 is a schematic diagram of the transverse sealer and palletizer shown in FIG. 1 .

Figure 6 is a top view of the preferred embodiment of the palletizer shown in Figure 1 .

FIG. 7 shows a side view of a preferred embodiment of the palletizer structure shown in FIGS. 1 and 6 .

Fig. 8 shows an explanatory view of a preferred embodiment of the longitudinal sealing machine according to the present invention.

FIG. 9 shows an enlarged side view of a portion of the transverse seal shown in FIG. 1 .

Referring to the drawings, wherein like elements are designated by like numerals throughout the several views. Referring specifically to Figure 1, there is shown a preferred embodiment of the apparatus and method of the present invention comprising a longitudinal sealer, a transverse sealer and a palletizer.

Cheese is first processed in cheese processing apparatus 10 in a manner known in the art. Then, in known manner, the processed cheese is transferred from the cheese processing device 10 to a filling tube device 12 for feeding the processed cheese into a tubular film strip made of thermoplastic material.

In more detail, the tubular film strip of thermoplastic material is formed in a manner known in the art by providing a continuous film or film strip of thermoplastic material and folding the film strip into a V-fold. After the strip of film of thermoplastic material has been folded into a V-fold, a longitudinal seal is formed at sealing station 20 (in a manner described in more detail below). Pressure rollers 16 are provided to securely seal and continuously draw the strip of thermoplastic material film. After the sealing station 20 forms the longitudinal seal and the film strip exits the press rolls 16, cheese is added to the tubular film strip using the filling spout. The strip of film and the cheese are then passed through a smoothing station 22 (in a manner described in more detail below). In the smoothing station 22, the tubular film containing the cheese is flattened to form a continuous strip of film or slices of cheese.

After the film web has been flattened and formed into a film, the film web then passes through a cooling station 14 . In the preferred embodiment, cooling station 14 includes a tank or container for storing a cooling liquid, such as water. In this embodiment, the cooling station 14 may include a plurality of rollers so that the strip of film and cheese is passed through the box in a coiled fashion. Preferably, cooling station 14 is configured such that the cheese-laden film strip passes through cooling water at a temperature between 0°C and 10°C for about 20 seconds. This makes the cheese whose temperature before cooling is 76.66 ℃ to 82.22 ℃, after cooling, its temperature drops to about 10 ℃ at the outlet end of the cooling station. The cooling station preferably includes an overdrive roller to provide a means of maintaining the film web under tension. The cooling station may also include scrapers and/or blowers (not shown) to dry the web of film exiting the cooling station 14 . Those of ordinary skill in the art will recognize that other suitable cooling arrangements may also be used.

After the film web exits the cooling station 14, it is conveyed to the transverse seal forming station, preferably by a pair of driven feed belts 39 . An endless belt control device and tensioning device 41 may be provided. Transverse sealing station 40 includes a first member 42 having a plurality of heated collets 46 and an opposed lower member 44 having collets 50 with opposed engaging surfaces. The transverse sealing station 40 provides a hermetic seal 102 transverse to the longitudinal or forward direction of travel of the film web. The film strip now comprises a plurality of slices 100 of cheese with hermetically sealed. The sealing station 40 will be described in more detail below.

After the transversal seal has been formed, the strip of film is then conveyed to the cutting station 60 in order to separate the individual slices of cheese slices 100 . Cutting station 60 includes means for sealingly cutting the strip of film transversely to define individual sheets. The cutting station 60 preferably also includes a palletizing device 70 for stacking the cheese slices 100 delivered from the sealing station into a plurality of stacks. Palletizing devices are discussed in detail below.

Referring now specifically to Figures 4 and 8, there is shown a preferred embodiment of the longitudinal seal 20 and smoother 22 of the present invention.

The preferred embodiment of the longitudinal sealing device 20 provides a novel and superior apparatus and method for forming longitudinal seals in film webs without intermittent stops. The longitudinal sealing station 20 includes a pair of stationary heating plates 24,25. Each plate includes a corrugated surface which forms an important part of the longitudinal sealer 20 . The rocking surfaces of the heating plates 24, 25 are opposed, and the heating plates 24, 25 are arranged such that the gap or distance between the opposed wave-shaped surfaces is fixed. The gap between the undulating surfaces of the heating plates 24, 25 is made fixed so that when the front and rear sheets of the open longitudinal ends of the film web are passed between the undulating surfaces, the front web of the film web and the rear sheet are pressed into close contact with each other.

In a preferred embodiment, the gaps between the wavy surfaces are tapered, having a shape that is wide at the top and narrow at the bottom, with an average pitch of approximately 1.59 mm. A means is provided for heating the two plates to a temperature sufficient to form a longitudinal airtight seal on the film web as it passes between the two plates 24, 25 without substantially The two surfaces are clamped together. The heating process may be performed by any suitable heating means, such as an electric heater 26 extending longitudinally through the holes 23 in each plate 24,25. The heating plate is heated to a temperature sufficient to form a hermetic seal between the two sheets of film tape, for example, the heating plate may be heated to a temperature of about 126.67°C. Pressure rollers 16 are arranged behind the sealing plate station 20 in order to ensure the sealing and to draw the film web through the longitudinal seal.

In a preferred embodiment, the filling tube 12 extends into the film web such that the outlet end of the filling tube 12 is arranged after the pressure roller 16 . In this way, cheese is added to the strip of film after the tube has been confined after the longitudinal seal has been formed.

In a preferred embodiment, an air bubble control member 28 is positioned prior to the smoothing station 22, the function of which is to determine the amount of cheese added to the film web. In this way, the amount of cheese fed can be controlled in an amount commensurate with the speed of the film web and the desired thickness and weight of the slices.

After the cheese has been added to the tubular film strip, the tubular film strip is conveyed to a smoothing station 22 . The smoothing station 22 includes an upper juxtaposed set of rollers 32 , a lower juxtaposed set of rollers 34 , and a pair of opposed belts 30 each disposed around a set of rollers 32 , 34 . As the cheese fed film web passes between the two belts, the cheese is flattened to form a film web consisting of a tubular thermoplastic film and a continuous sheet of cheese. In the smoothing station 22 there are provided means 36 for adjusting the distance between the belts 30 in order to control the thickness of the film strip of tubular thermoplastic material and cheese.

As shown in FIG. 3 the strip of film forms a tubular portion having a hermetically sealed longitudinal seal 106 (the longitudinal seal being indicated by the portion drawn between the arrows in FIG. 3 ). The film strip is preferably sealed along the longitudinal top edge of the front surface of the film strip such that flap portions 104 are defined, as shown in FIG. 3 .

After the longitudinal seal 106 is formed, as described above, the film web is conveyed through the cooling station 14 and the flap 104 is then folded over the front surface of the film web as shown in FIG. 2 . Before the web of film reaches the transverse sealing station 40, the flaps are folded in a manner known in the art. Preferably, at the transverse sealing station 40 the flap 104 is partially sealed to the front surface of the film strip in the transverse seal area.

Reference is now made to FIGS. 5 and 9 . The figure shows a preferred embodiment of the transverse seal. The transverse seal includes an upper seal member 42 and a lower seal member 44 each having a plurality of opposed collets or wedges 46 and 50, respectively. As best shown in FIG. 9, the sealing members 42 and 44 are arranged so that when the film web is transported through between the upper wedge 46 and the mating lower wedge 50 of the transverse sealing station 40, the desired transverse In the sealing area, the top and bottom films of the strip of film are fused together. Upper wedge 46 of upper member 42 is heated to sealing temperature in a manner known in the art. For example, upper wedge 46 may be heated by an electric heater and brush arrangement. Wedges 46 and 50 may be made of any suitable material such as aluminum. The upper wedge 46 preferably includes a removable part 48, and the lower wedge 50 engaged therewith preferably also includes a removable part 45, the material of the removable part 45 is softer than the material of the part 48 which cooperates with the upper wedge 46. some. For example, the removable part 48 of the upper wedge 46 may be made of a metallic material such as aluminum, while the removable part 45 of the lower wedge 50 may be made of a resilient material such as polyurethane.

For quality control and to achieve a uniform transverse seal, each heated wedge 46 includes a thermostat 54 for controlling the temperature of each wedge. Therefore, the temperature of each wedge can be adjusted individually.

Means are provided for pushing the opposing wedges into engagement with the cheese film strip as it is conveyed through the sealing station 40 . As shown, in the preferred embodiment, the means for urging the wedges together includes a track and chain arrangement. Each cleat is secured to a chain arrangement mounted on tracks 56,58. As clearly shown in FIG. 9 , the chain arrangement comprises a chain portion having rollers 52 and 53 fixed to respective links of the chain at spaced intervals from each other. Rollers 52, 53 rest on elongated endless tracks 56, 58, respectively. The elongated endless tracks 56, 58 are positioned such that the cleats 46 and 50 are disposed in meshing relationship at a predetermined interval (discussed in more detail below).

The strip of cheese film in the tubular film is preferably conveyed through the jaws 46,50 of opposed sealing members 42,44 so that an airtight seal is formed between the two inner layers of film strip material. The seal is formed such that after the seal has been formed and the package is torn at the seal, the seal is preferably broken. This is in contrast to currently made seals which, after the seal has been formed and the package is torn, are broken delaminated by separating the top non-sealing layer of cheese from the film strip with the inner or sealing layer. The bond between them is broken. This proposed packaging structure is achieved by proper selection of thermoplastic materials. For example, one proposed material consists of a polypropylene layer coextruded with a polyethylene sealant layer with an intermediate attachment layer.

In a preferred embodiment, the sealing temperature is between 126.7°C and 137.8°C and it takes about one second for the jaws to move with the film strip from the engaged first position to the disengaged position. The pressure applied between the opposed jaws at seal location 106 is sufficient to dislodge substantially all of the cheese in the transverse seal area from between the two layers of thermoplastic film web material.

Suitable means are provided for driving the two chain structures in the sealing members 42 and 44 . Where the cheese slices are defined between the jaws, the sealing portions of the jaws 46 and 50 are preferably such that the transverse seal 102 between adjacent cheese slices 100 has a dimension of about 6.35 mm. The wedges 46, 50 are spaced apart from each other on their respective chains such that the distance from the start of one cheese slice to the start of the next cheese slice (including the transverse seal 102) is about 8.89 cm.

This arrangement can produce individual cheese slices 100 at high speed, since the heating wedges 46 and cooperating wedges 50 rest on or move with the transverse seals at a fixed time period, the film web can run at a relatively fast speed, thereby A higher productivity was obtained. For example, the film web can be moved at a speed of about 91.44 meters per minute, or about over 1000 sheets per minute can be produced.

After the transverse seal 102 has been formed, the film strip is sent to the cutting station 62 . A loop control device 63 and a tensioning device 67 are provided. Referring specifically to Figures 5 and 7, the cutting station includes a pair of mandrels 64, 66 having cutting tools for cutting the film strip at the transverse seal so that each individual sheet can be defined. After the strip of film has been cut to form individual slices, cheese slices 100 are ready to be palletized onto each stack for packaging. Sheet 100 is unloaded from cutting station 62 and placed on palletizer 70 . Referring now specifically to Figures 6 and 7, there is shown a preferred embodiment of the palletizer of the present invention. The palletizer 70 provides an efficient method for selectively stacking a predetermined number of cheese slices 100 produced by the forming, sealing and cutting apparatus discussed in detail above onto multiple stacks.

The palletizing device 70 comprises a perforated conveyor belt, the conveyor belt 72 being preferably endless. The endless belt 72 is preferably perforated such that about 25% or more of the conveyor belt 72 is open. A vacuum system 78 is arranged inside the endless belt 72 , and the pressure difference generated by the vacuum system 78 and the atmospheric pressure can keep the cheese slices 100 on the outer surface of the endless belt 72 . The endless belt 72 rotates about two rollers or drums 74 and 76 driven by means known in the art. The vacuum system 78 provides sufficient vacuum so that the cheese slices 100 can be attached to the surface of the belt 72 as the belt advances. That is, the cheese slices 100 remain on the belt as the belt runs around the drum 76, and the cheese slices 100 remain on the belt even when the slices 100 run to the bottom of the palletizer 70 in an upside-down position. . Thus, even when the slices are at the bottom of the belt 72, the vacuum of the vacuum system 78 is sufficient to overcome the force of gravity pulling the cheese slices 100 down.

Multiple palletizing stations 82a-82f are provided to accommodate the high production rates of the packaging system described above.

An air injector 80a-80f is provided prior to each palletizing station 82a-82f, and when activated, the air injector 80a-80f applies air pressure onto the leading edge of the cheese slices 100 running on the belt 72. As the slices pass under the air injectors, the injectors provide sufficient air pressure through small holes in the belt to exceed the vacuum pressure as the cheese slices 100 pass through the injectors 80a-80f, causing the cheese slices 100 to flake off. In this way, the cheese slices 100 fall under the force of gravity into the desired palletizing station. In front of each palletizing station 82a-82f is preferably provided a sloped plate or ramp 90. If the cheese slices 100 fall off the conveyor belt 70 before the belt has fully entered the palletizing station, this inclined plate ensures that the cheese slices will slide onto the plate 90 and be transferred to the palletizing station. At the start of the palletizing station a photosensitive element 84 is provided for counting the number of cheese slices 100 to be dropped to each palletizing station 82 .

In the preferred embodiment, a palletizing system with significant advantages is configured to use an intermediate slice receiver to temporarily accommodate the first few slices of cheese falling into the palletizing station 82 . In a preferred embodiment, the intermediate sheet receiving means includes a first or upper set of retractable fingers 86 . Preferably also be provided with a group of retractable claws 88. At this time, the set of retractable claws 86 is arranged on the middle layer between the top and the bottom of the specific stacking station. When peeling the cheese slices 100 into a specific stacking station, this upper group of palletizing claws is just as the middle falling stop point of the cheese slices 100 . After a predetermined number of slices have fallen onto the upper set of fingers 86 , the upper set of fingers 86 is retracted, allowing the cheese slices 100 stacked in a particular palletizing station to fall into the lower set of fingers 88 . The lower set of claws 88 is particularly important when the number of cheese slices 100 to be palletized in each palletizing station is large. For example, certain projects may call for stacks of cheese slices 100 that are 10.16 centimeters high. The advantage of the upper set of claws 86, if there is no upper set of retractable claws 86, is well illustrated by the trajectory of the cheese slice 100. When the ejector 80 peels off the cheese slice 100, the cheese slice 100 begins to fall in an angled direction with its leading edge in the lowest position. If the cheese slice 100 needs to be dropped a long enough distance, the cheese slice will turn somersaults instead of laying flat in an orderly manner, thereby interfering with the palletizing process. The upper set of hooks 86 provide an intermediate stop for the cheese slice 100 . The cheese slices 100 need only fall a short distance to reach the intermediate stop provided by the upper set of hooks 86 for the cheese slices 100 . The cheese slice 100 falls only a short distance to the upper set of claws 86 . Therefore, the stability of palletizing can be guaranteed.

After a certain number of cheese slices 100 have been placed on the upper set of claws 86 , the upper set of retractable claws 86 retract and the entire stack of cheese slices 100 falls onto the lower set of retractable claws 86 . Since a certain number of slices 100 have already been placed on the stack, the cheese slices 100 that now come off the conveyor belt 72 and fall onto the existing stack of cheese slices 100 will fall only a short distance. That is, the distance that the cheese slices 100 need to fall is only the distance between the conveyor belt 70 and the top of the pallet. When all the cheese slices 100 included in a particular stack have been palletized, the lower set of retractable claws 88 are retracted and the stack of cheese slices 100 falls onto the transfer table 92 .

In another selected embodiment, the intermediate sheet receiving means may include an elevator mechanism that initially raises to a predetermined intermediate height and lowers it to accommodate the stacking speed of the sheets at the palletizing station. In this embodiment, after the last cheese slice 100 has dropped onto the stack, the lift mechanism is preferably lowered to carry the stack onto transfer table 92 .

Devices such as programmable controllers or microprocessors are preferably operatively connected to corresponding injectors 80a-80f at each palletizing station 82a-82f so that the cheese in each stack on 82a-82f The number of sheets 100 is optionally adjustable. The control device also makes it possible to drop the sheets only into certain palletizing stations and to leave out other palletizing stations. In a very advantageous embodiment, the injectors 80a-80f and control means are efficiently made to enable continuous or sequential filling of the palletizing stations 82a to 82f. In this embodiment, all injectors apply positive pressure to the front of each palletizing station before filling any of the palletizing stations 82a-82f. When transporting the cheese slices 100 through the first injector 80 (corresponding to the first palletizing station 82a), the first injector 80 applies positive pressure to peel the cheese slices 100 from the conveyor belt 72 and drop to the first yard. Stacking station 82a. After a predetermined number of cheese slices 100 have fallen into the first palletizing station 82a, the injection device at the first palletizing station stops applying positive pressure. Thus, the vacuum pressure from the vacuum device 78 will continue to hold the next cheese slice 100 on the conveyor belt 72 until the cheese slice 100 reaches the ejector 80a at the second palletizing station 82b. The ejector 80b at the second palletizing station 82b will continue to operate until the second stack has been filled with the predetermined number of sheets. When the second stack has been filled, the ejector 80b at the beginning of the second palletizing station 82b will be closed so that the next cheese slice 100 will be transported to the third palletizing station 82c. This process continues until each palletizing station has been filled with a predetermined amount of sheets. This method works extremely well since it does not require repeated breaks of the vacuum. The air ejector overcomes the vacuum pressure without interrupting the operation of the vacuum device.

Stacks from each station 82a-82f are preferably placed on another conveyor 92, as shown in FIGS. The direction of advancement of the conveyor 92 is transverse to the direction of motion of the endless belt 72 of the palletizer 70 . In this way, the stack of cheese slices 100 is transported from the palletizer 72 to a station where it is further processed manually or automatically.

Thus, the packaging and palletizing system of the present invention provides a means of packaging each slice of hermetically sealed cheese with high efficiency and high production rates. The sealing means provided by the present invention provide a hermetic seal along the longitudinal edges of the film strip. When the cheese is packed into the tubular film strip, a transverse airtight seal is formed. The device provides a hermetically sealed package of cheese with a longer shelf life than currently used sliced cheese products. In addition, the provision of longitudinal and transverse seals allows for continuous movement of the film strip without interruption of operation as is the case with conventional sealing systems. Sheets processed and packaged according to the present invention provide an excellent final packaging product. A seal is formed between the two inner layers of low heat fusing material such that when the wrapper is pulled apart to open the individual sheets, the seal is broken. Unlike the packaging commonly used today, when the package is opened, the sealant layer is peeled from the top layer of the packaging material, forming rough tear lines, resulting in a "tightening" phenomenon. With the package of the present invention, there is a clean opening and eliminates binding problems when the bond between the two sealing layers of polyethylene is compromised.

In addition, since polyethylene can be used as a sealing layer, the packaging material can be easily separated from the processed cheese. This eliminates parts such as clear pumps for handling the cheese with less cohesive tissue and good separation. The method and apparatus of the present invention also allow the top layer of packaging material to be made of polypropylene material. This has significant advantages, since polypropylene is much less expensive than currently used materials such as Mylar.

The present invention also provides a high efficiency palletizer which receives sheets produced by high speed manufacturing machinery and accumulates the sheets into stacks. At the palletizing station, the number of flakes can be selectively varied, allowing great controllability during production.

The foregoing description of selected embodiments of the invention has been presented for purposes of illustration and description, and the described embodiments are not intended to be exhaustive or to limit the invention in the form in which it is precisely disclosed. Obviously many modifications and variations are possible in light of the above teachings. The embodiment selected for illustration is to better explain the principle of the present invention and its practical application. The scope of the invention is defined by the following claims including all equivalents.

Claims (16)

1. An apparatus for palletizing monolithic shaped articles on at least one palletizing station (82a-82f), characterized in that it comprises: an endless belt (72) having a plurality of apertures positioned such that at least a portion of the belt is placed over at least one palletizing station (82a-82f); Drum means (74, 76) for moving the belt (72) causes the belt (72) to move through at least one palletizing station (82a-82f) with the bottom of the belt facing the at least one palletizing station (82a-82f); Vacuum device (78) for providing vacuum along the product-holding portion of the belt through the aperture of the belt (72), continuously providing vacuum during the palletizing process so that the monolithic loaded product (100) remains in the on the belt (72); operatively connected to selectively engageable air injectors (80a-80f) that provide positive air pressure at the air injector station through apertures in the band (72), The air injector station is arranged downstream of the product holding portion of the belt (72) at the beginning of at least one palletizing station (82a-82f), the air injectors (80a-80f) during palletizing is continuous operation to provide positive air pressure to the orifice at the air injector station while vacuum is provided at the product holding portion of the belt (72), so that the WIP sheet (100) moves through the The leading edge of the article sheet (100) is pushed away from the belt (72) by the positive air pressure when the small holes of the air injector stations (80a-80f) are closed. 2. Apparatus as claimed in claim 1, characterized in that the belt (72) comprises an endless belt and the drum means (74, 76) for moving the belt comprise means for pushing the belt forward. 3. Apparatus according to claim 2, characterized in that the vacuum means (78) provide vacuum to at least the air injector stations (80a-80f) through small holes surrounding the annular belt (72). 4. Apparatus according to any one of claims 1 to 3, characterized in that it comprises a plurality of palletizing stations (82a-82f) arranged in sequence, comprising a respective air The injectors (80a-80f) also include means at each palletizing station (82a-82f) for selectively engaging and disengaging the air injectors (80a-80f). 5. The apparatus as claimed in claim 4, characterized in that it comprises means placed at each palletizing station (82a-82f) for counting the number of individual pieces (100). 6. The apparatus according to any one of claims 1 to 3, characterized in that at least one stacking station (82a-82f) also includes a ) The middle monolithic receiving device (86) of the product monolithic (100) at a station in the middle of the top and bottom. 7. The apparatus as claimed in claim 4, characterized in that at least one palletizing station (82a-82f) also includes a top and a bottom for receiving the at least one palletizing station (82a-82f) An intermediate monolithic receiving device (86) for a product monolith (100) at a central station. 8. The apparatus according to claim 5, characterized in that at least one palletizing station (82a-82f) further comprises a top for receiving at the at least one palletizing station (82a-82f) 9. Apparatus according to claim 6, characterized in that said intermediate monolithic receiving means (86) comprise a plurality of retractable claw-like members. 10. Apparatus according to claim 7, characterized in that said intermediate monolithic receiving means (86) comprise a plurality of retractable claw-like members. 11. Apparatus according to claim 8, characterized in that said intermediate monolithic receiving means (86) comprise a plurality of retractable claw-like members. 12. The apparatus of claim 6, wherein said intermediate sheet receiving means comprises an elevator and is configured to operate at a speed sufficient to provide space for an adjacent sheet and sufficient to remove the last product sheet (100 ) after palletizing at least one palletizing station (82a-82f), reduce the speed at which the first product single piece (100) palletized at least one palletizing station (82a-82f) is lowered to a predetermined height The device of the lift. 13. The apparatus of claim 7, wherein said intermediate sheet receiving means comprises an elevator and is configured to operate at a speed sufficient to provide space for the next sheet and sufficient to remove the last product sheet (100 ) after palletizing at least one palletizing station (82a-82f), reduce the speed at which the first product single piece (100) palletized at least one palletizing station (82a-82f) is lowered to a predetermined height The device of the lift. 14. The apparatus of claim 8, wherein said intermediate sheet receiving means comprises an elevator and is configured to operate at a speed sufficient to provide space for an adjacent sheet and sufficient to remove the last product sheet (100 ) after palletizing at least one palletizing station (82a-82f), reduce the speed at which the first product single piece (100) palletized at least one palletizing station (82a-82f) is lowered to a predetermined height The device of the lift. 15. The apparatus of claim 1, further comprising means for selectively engaging and disengaging a respective air injector at each pallet position. 16. The apparatus of claim 15, further comprising means placed at the palletizing station for counting the number of individual pieces.

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