IE921503A1 - Method and apparatus forming and hermetically sealing slices¹of food items - Google Patents

Abstract

In a process for packaging a food item formed into a toft nass wherein the food ltaa 1« wrapped in individual tllcae, the inprovaeent conprlsing, foldifag a continuous web of hast-»ealable thermoplastic aaterial into V-felded condition including a folded longitudinal aide and aa open longitudinal aide; continuously noving the »*b in a forward direction; continuously forming hermetic aeal along the open longitudinal aide of the web in V-felded condition to define a continuous tubular web; inserting the food item into the tubular web, after the food ltaa ia inserted, continuously flattening the web to fora, * continuous slice of the food It·· disposed between a top layer and a bottoa layer of the web; forming a plurality of hermetically sealed cross-eeals at predetermined intervals in the flattened web while the web la continuously served forward, whereby hermetically sealed slices of the food Iter are defined.

Description

In a process for packaging a food item formed into a toft nass wherein the food ltaa 1« wrapped in individual tllcae, the inprovaeent conprlsing, foldifag a continuous web of hast-»ealable thermoplastic aaterial into V-felded condition including a folded longitudinal aide and aa open longitudinal aide; continuously novi ng the »*b in a forward direction; continuously forming hermetic aeal along the open longitudinal aide of the web in V-felded condition to define a continuous tubular web; inserting the food item into the tubular web, after the food ltaa ia inserted, continuously flattening the web to fora, * continuous slice of the food It·· disposed between a top layer and a bottoa layer of the web; forming a plurality of hermetically sealed cross-eeals at predetermined intervals in the flattened web while the web la continuously served forward, whereby hermetically sealed slices of the food Iter are defined.

PATENTS ACT, 1964 COMPLETE SPECIFICATION OPEN TO PUBLIC INSPECTION UNDER SECTION 28 AND RULE 23 JNL. No... Z.If.L OF/.7//7 A3 METHOD AND APPARATUS FORMING AND HERMETICALLY SEALING SLICES OF FOOD ITEMS APPLICATION No___ SPECIFICATK '__ SCHREIBER FOODS, INC., a corporation organised under the laws of the State of Wisconsin, United States of America of 425 Pine Street, P.O. Box 19010, Green Bay, Wisconsin 54307-9010, United States of America. -1έ IE 921503 MRBO0 ARD APPARATUS faRMIRG MB SUMOTCAriT 8SALXHB SUCKS OP mop ITOtS BMBBgWLg PffWBM The prevent Invention relates generally to an apparatus and method for packaging food items and nor* particularly to an apparatus and proeeso for packaging and stacking food items la hermetically aaalad Individual slices.

Various methods and apparatus have bean proposed and utilized for tha manufacture and packaging of individual slices of food Items ouch as ch··*·. Although the available apparatus and methods are suitable for the packaging of Individual slices, they are not without disadvantages.

Typically, the package for tha individual slices la formed from a eoatinuoue film or web of a thermoplastic material. The web is first folded in v-folded condition. As need herein, the ten V-felded condition refers to a length of material which has been folded over onto itself no as to form whet may subsequently be Identified as a front sheet end e rear sheet which are Joined by the fold at the bottom, ae* as to approximate the letter V* in cross eeetion. The web ia typically folded suen that the rear sheet is longer than the front sheet to define e flap section in the rear sheet, which extends beyond the top edge of the front shoot. The flap section ie typically folded over onto the front sheet to form a tubular web. - iftIE 921503 After the flap is folded over op the front ebeet, a tubular web le defined. The processed eheevv le then inserted into the tube end the web end eheeee ere flattened. Subsequently cross-seals ere foraed along the longitudinal length of the tubular- web et predetermined interval·. After the tube le cross-sealed it le severed along the cross-seals in order to produce the individually wrapped slices of cheese. Several processespreeently exist -for providing the transverse or cross seal.' .... eria eommly used Method, the cross-seal* axe foraed by subjecting ths flattened e«b (with the inserted cheese) to'pressure, at the desired location, to fora the transverse cross seal, the pressure ie applied such that aa ultra thin layer or file of cheese is left ia the transverse sealing section. She ultra thia layer or film of cheese acts as aa adhesive to eeal the two layers of the plastic web together. After thia cheese· eeal has been foraed. the veto is severed •V the-sealed sections to define individual slices of cheese.

Although the ’cheese” seal provides an adequate seal for the individual slices of cheese, the ehelf life of the cheese product after it is packaged . is not as long as would be desirable. This is due to the fact that the cheese seal is * relatively weak seal which will eventually deteriorate and which allows air to enter into the slices under ordinary atnospherlc conditions. The Slices will soon dry oat or spoil.

Other Methods of providing a transverse cross-easi have also been disclosed. For exaaple, V.S. Patent No. 4,586,317 (Bussell) discloses an arnngenant for foraing a seal la packaging neterial (such ae processed cheese) which utilises a sealing elenent having a finite number of raall channel· in the . * J - 1 surface. The packaging film 1« co-eztruded or lsalnated to· include en inner sealing layer of teletlvsly low· thermal plastic nalt tamperatnre and aa outer laysr which does not nalt under eealing conditions- The tuba isbeated and coagrcsaaed transversely by tbs sealing elements thereby sealing the internal layers of tbe packaging file together. Although the apparatus sad sothod disclosed In this patent provide a sol table crossseal, tjs finished product suffers from the seas disadvantage*. that are described above, since the longitudinal seal la foroed by providing a flap in the Vfolded condition wsb and eiaply overlapping the flap with the upper surface .of the front «hoot of the web, a poor seal is foroed. Thus, air and other atnoapherlc products will eater Into the wrapped slices of cheese, reducing the shelf .life of -the product.

Therefore it would be desirable to provide an individual slice of cheese which is wrapped In a package which is hermetically sealed on all aides. To accomplish thia> a heroetic seal suit be foroed along the longitudinal edge of the web as wall as along the transverse or ervae-seals. A hermetically sealed package would have several advantages, for exaaple, a hermetically sealed slice would permit iroerslon for cooling and sanitising. further, a hermetically sealed slice is essential to aseptic packaging. for purpoaes of manufacturing economy, it would be desirable to provide the longitudinal seal and croea-seals In a continuous process. Sons presently available Methods, however, form seals in an intermittent fa ahi on. Typically, in these presently available Methods, a seal la foroed by heated jaws which reciprocate between an open and s closed, position. When tho Jews dose, they seal the desired section of the web. After the section has been sealed.

J the Java retract and tbs web 1· moved for th· sent section which .is to ba sealed^ ..Shia process, however, haa obvious disadvantages. B* web.jsust. be continuously stopped and started In accordance with «ha reciprocating nove«ont .of -the jaws. - Cueh a device ia disclosed for example in U.S. Patent Ho. 2.460,«60 (Langer).

,,. ..- Another .prohlae which ia encountered in th· processing and peckaging of cheaea slices (as wall aa JLn the .packaging .of -other, products which are packaged l Therefore, in view of the above, it is an object of the present invention to provide an apparatus and a method for producing individual slice· of food items, such aa processed cheese, which are hermetically packaged.

It la a farther object of the present invention to provide an apparatus and method for providing a continuous and efficient arrangement for forming ' . hermetic Mali along all of the edges of the packaging web.

'Xt is still « further .object of the present Invention to provide an apparatus and mthod for stacking the desired nooMar of the slices of food items, such as eheese, in the stacking locations from a rapid packaging system.

SSEMAKY Of TOB niVENTIOM To -achieve the foregoing and other objects and in accordance with the purposes of the present invention, an apparatus and method are provided for forming a hermetically sealed package for a slice of a food item, λ web of thermoplastic material ia first formed into a tubular arrangement with a hermetic longitudinal seal. To form the tubular arrangement, means are provided for folding a continuous web of thermoplastic material into V-folded condition and for continuously forming a hermetic seel along the open longitudinal Odge of the V-folded web. The hermetic seal is'formed between the inner surfaces of the front and rear faces of the web to define a tubular web member. The'cheese which has been formed into a soft mass, is than inserted into the tubular needier and the tubular aenber is flattened to form a continuous web. Means sre provided for forming hexmotic slip scaled cross-seals which ere disposed substantially transverse to tbs longitudinal forward moving direction of the web.

In e preferred sshndlswnt of the invention the Mans for forming the longitudinal seal lnclud· s pair of stationary plates with opposed undulating surfaces. The plates ere arranged oueh that a fixed predetermined distance ie defined between the undulating surfaces of the plates. The plates are heated end the - 9 1 J veto is passed throughths space between the two plot·*. Λ9 ti* web novss through the plate*, the undulating surface· alternatively fore* th* front sad rear faces of the web into intimate contact.-«nth each other to thereby for» a hermetic longitudinal weal without clasping the ill· between the surfacea.

In another aspect of the invention, a stacker ia provided for stacking the slices fro· the wrapping and cutting, machines, into a plurality of stacks. The stacker includes a conveyor belt, which include· a plurality of apertures, onto which the slices of cheese are disposed. A vacua» system provides vacuum through the apertures to·hold the slices of cheese on the belt, naans ere provided for earing the belt in order to advance the slices of chocs* to the stacking locations.

The vacuum is sufficient to hold the slices of cheese on the belt even when the slices sn disposed on the bottom of the belt. A plurality of stocking locations are seguentially provided. Xeeh of the stacking locations includes-means for providing positive air pressure' at the leading edge of tha cheese slice as it approaches eaoh stacking location while it is being moved on the belt. As the cheese travels oo the belt, the positive sir pressure overrides the vacuum forces . holding the aliee on the belt thereby ’’peeling the cheese slice off of tbe belt and tbs fores of gravity cause· tha slioe of cheese to -fall Into ths predetermined stacking location. In a preferred esbodiment, means ere provided for selectively engaging or disengaging the positive air pressure at the leading edge 'of each •tacking location. Thia stacking arrangement thus provides an apparatus for stacking a predetermined nober of wrapped cheese siloes being produced et a relatively rapid production rate Into a plurality of stacks.

IE 921503 ϋ . · - 7 - Additional objects, advantages and novel features of the invention ~wlll be rat forth in pert in the description which follows, end in pert will becone apparent to those skilled In thw art upon exaaination of -the following or nay bo loaned by practice of the Invention. She objects and advantages of the Invention nay ho obtained by mans of the eoabinatleas particularly pointed out In the appended claims. . · . . · . OlBUBB&HKStSLfiOBJBfiOaa FIO- 1 is a sohsastlc representation of a preferred esbodiaant of tho apparatus and Method of the present'invention inclading the longitudinal sealer, the cross sealer, and the staekor. FIG. 2 Illustrates a preferred eabbdlmnt of a slice of cheese which has been railed with the process and apparatus of tbs present invention (with the flap folded over). FIG. 2 illustrates the slice of choose illustrated in- FIO. 2-with the flap unfolded. FZO. 4 is an illustration of a preferred «·bodlnant tho longitudinal sealer and flattening mana of the present Invention. fig. $ is a sohsaatic representation of the cross sealer end stacker illustrated in FZC. 1. FIO. 6 is a top View of a preferred enbodimnt of tho stacker illustrated in Fig. 1. FIG. 7 Illustrates · side view of the preferred eabodlaent of tho stacking arrangement illustrated in Figs. 1 and 6. FIG. B io an illustration of a preferred eahodlaont of the longitudinal sealer of the present in- i veatien. u J ΠβΛ 9 Illustrates an enlarged aid· view of a section of tbe cross sealing arrengeaient Illustrated In fig. 1. .

Rsfsrencs will now fee made to tbe drawings wherein like elements are referred to with like refer· ence minerals throughout the wsrioua drawings. Referring «pacifically to tig. 1, a preferred eefcodimcnt of the arrangement and process of tbs present Invention Including tbe longitudinal aealer, cross easier, and thy stacker la Illustrated.

Cheese le first processed. In a manner known in tbe art, fey cheese processing naans 10. The processed cheese la then transferred, in a known manner, from tbe cheese processing means 10 into a fill tube arrangement 12 which ie used to Insert tbe processed eheeee into a tubular web made of thermoplastic material.

In more detail, the tubular web of thermoplastic material la formed fey providing a continuous film er web of thermoplastic material and folding tbs mb into V-folded condition, in wanner known ia tbe art. After tbe web of thermoplastic material has been folded into tbe V*»folded. condition, a longitudinal seal la formed at a sealing station 20 (in a manner described in swrs detail below). Mp rollers 16 are provided to aeoura the . seal and continuously pull the web of thermoplastic material. After the longitudinal seal is fonsed^at the sealing station 20 and leaves tbs nip rolls 16, the Cheese is Inserted by means of the fill tube 12 Into the tubular web. Tbe web end cheese ere then passed to a flattening station 22 (also described in more detail below). At tbe flattening station 22, the· tubular web with the cheese ie flattened to* Coxa a-oentiuttoua web or elice of cheese.

After the web has been flattened end foisad into the Hla, the web le tbea paaeed through a cooling ate tion 1<ϊ.·.'1η bne preferred sahndlmant, the cooling station 14 ccaprleea a tank or container for bolding a cooling liguid, ouch aa water. In thia anbodlamttt, the ooolihg station 14 nay include a plurality of rollers such that the web end oheeas are paaaed through the tank in a winding fashion. Preferably tne cooling station 14’is configured such that the web with the cheese paseoe through the cooling water for approxinately 20 seconds with the water being at between 32*f and soer. This sill take the cheese which usually starts off et e teaperature of between 170I end 180’f and cool the cheese down to appreslnately SO*t at tbs exiting end of tho cooling station 14. Preferably, the cooling station includes a roller which la over driven to provide naans for keeping the wab taut. The cooling station nay also Include scrapers and/or air-blowers (not shown) to dry the web aa it exits fro· the cooling station 14. It will be recognised by those skilled in the art that other suitable cooling aeaas nay elec be used.

After leaving the cooling station 14. the web is conveyed, preferably by a pair of driven feed belts 39, to tha station which fonts the cross seals.

A loop control neane and tensioning weans 41 nay be provided. The transverse or eroae sealing station 40 Includes a first nsaber 42 with a plurality of heated jaws 44 end an opposed botton aaafeer 44 with jaws 30 with opposed engaging surfaces. The cross sealing station 40 provides e hematic eeel 102 transverse to the longitudinal or forward noviag direction of the wob. The web .now includes a plurality cf slicos of - 9 I eh··»· 100 which ar· boxaMtieally sealed. Th· cross sealing station 40 is described in wore detail below.

After the transverse Or cross seals have bean fonsd, the vab is then conveyed, to a cutting station 00 to separate tho individual slices of cheese 100. The station 40 includes bdsns for cutting tho web •long tha cross-seal to define the individual slices.

Th· station 40 also preferably includes a stacking arrangeMint 70 which stacks the slices 100 being conveyed from the croaa scaling station 40 into a plurality of stacks.

The stacking arrsrtgensnt is described ia eore detail below. thb t/wc gyftttP Keferring now specifically to figs. 4 and B, a preferred eadbedinant of the longitudinal sealing arrangenent 20 and tbe flattening arrangenent 22 are illustrated.

Tho preferred e^xxllnent of the longitudinal or long sealing errangesMnt 20 previdea a novel and advantageous apparatus and process for forning the longitudinal seal ia the web without stopping the web in an intermittent fashion. Tho sealing station 20 Includes a pair of stationary boated plates 24, 25. tach plate includes an undulating surface which fozns an iaportsnt part of tbs longitudinal sealer 20, Tho undulating surface· of the plates 24, 25 are opposed and tbs plates 24. 23 are disposed such that s fined gap or distance exist· between the opposed undulating surfaces. The gap between the undulating surfaces of tbe plates 24, is fixed such that as tbe front and rear sheets of the open longitudinal end of tbe web are conveyed between the undulating surfaces, the. front and rear dheets of the web are forced into intimate contact with each other.

In a proferred* eabodleent th· gap between the undulating surface· ie topared having « wider gap et the top than the botton with an average gap divtance of appruxieately 1/16 of an inch, (leans are provided for heating the two plate· to e taagiaratur· sufficient to fox* a longitudinal hereetlc seal aa the web ie conveyed between the two plates 14 and IS Without physically clanping the two surfaces together. The heating nay be provided by any suitable heating means, for exaaple, an else trie-heater 24 which ie inserted longitudinally through aft aperture 23 in each plate 24, IS. The plates are heated to a tenperature sufficient to fore a hematic seal between the two sheets of the veto, for exanple, the plates nay be heated to a temperature of approximately 260*r. Kip rollers 16 ere provided after the sealing plates station 20 to secure the eeel end pull the web through the longitudinal sealer.

In a preferred embodiment, toe fill tube 12 extends down into toe web such that the exiting ead of the fill*tube 12 ie disposed after the nip rollers 16.

In this manner, the cheese is inserted into the web after the longitudinal seel has been fomed and a tuba has been defined.

In a preferred embodiment, a bubble control element 24 ie disposed before the flattening station 22. The bubble control unit 28 functions to detemine too aaount of cheese which ie being inserted into the web. Zn tola nanner, the flow ef cheese nay be controlled as appropriate for the speed ef too web and toe desired thickness and weight of toe slice.

After toe cheese ie inverted into toe tubular wob, the tubular veto ie conveyed to a flattening station 22. The flattening station 22 includes a first or upper set ef juxtaposed roller· 32, a lower cat of juxtaposed roller· 34, and a pair of opposed belt· 30. - 12 Each belt 90 isdleposed around one a«t of roller* 92, 34. As.the web with. the Obese· inserted therein peases between the two-belt·, the cheese is flattened to for» • «orb ccnprislng the tubular thejnsoplastle fila and a continuous ellca of cheeee. Means 36 are provided In the flattening station 22 for adjusting tbe distance between the belts 30 to control the thickness of the «eb of tabular thermoplastic aatsrial and oheese. - - as- illustrated in Fig. 3, the web la foxsed into a tubular section, with a hermetically sealed longitudinal seal 106 (the longitudinal aaal la represented in Fig. 3 by the section illustrated between the arrows). Preferably, the wab la sealed along the top longitudinal edge of the front fee· of the web such that a flap portion 104 is defined as illustrated in Fig. 3.

After the longitudinal seal 106 la forned, tbe web la conveyed through the cooling station 14, as described above, and then the flap 104 le folded over onto the front face of-the web aa illustrated In Fig. 2. Xhe flap nay be folded over in a Banner known in the art before the web reaches the cross-seeling station 40. Preferably, the flap 104 la partially sealed at the cross seal sections to the front face of the «rob at tbe cross sealing station 40. tHE-CRg» ΗΜ,ΗΚ,ΠΕΕΜΒ Referring now specifically to Tigs. 3 and 9, a preferred enbodlaent of the cross-sealing arrangement is disclosed. The cross-sealing arrangement Includes an upper seeling nenbor 42 and a lcwer sealing aeober 44, with each of tha sealing Mahers including a plurality ot opposed Jew» or cleats 46 end 50 respectively. As best illustrated in Fig. 9, the sealing seaborn 42 and 44 era arranged each that as the - 12 I - 13 «b 1· conveyed through the sealing rtatlon 40 between th· upper cleat 44 and th» engaging lower cleat 90 tha top and bottoe layers of the Ilia web are aargad together ia the desired oross sealing section. Tha oleate 44 of the upper aestber 42 are heated to the sealing teweratuxa, la a Banner known in the art. For example, -the top cleat 46 »ay be heated hy an electrical beater and brush arrangeaent. The cleats 46 and 40 aay be aede of any suitable aaterial such as aluainaB. The top cleat 44 preferably-includes a removable section 46. The engaging bottom cleat SO alee preferably include· a removable section 45, which ie uada cf a Better material then the top Bating section 48 of the cleet 44. Tor example, the removable section 48 of the top cleat 46 nay be eadn of a awteillc materiel such as aluminum and the removable section 45 of the lover cleet 50 Bay be aade of a resilient aaterial each ee polyurethane.

For purposes of quality control and to achieve uaiforuty in the cross seals, each of the heated cleats 44 includes a theraostat 54 which control» the tesgmrature of each individual cleat. Therefore the teaperaturo of each cleat ean be adjuated separately.

Means are provided for urging the two opposed cleets to engage the web of cheese as it is conveyed through the sealing station 40. As illustrated in the figures, in the preferred embodiment, the mans for urging the cleet together eoeprisee a track and chain arrangesnnt. Bach of the cleat· 1· attached to a chain arrangement which rides on a track 54, 58. The chain arraageaent, illuatrated beat in rig. 9, include· aectiona of chain including rollers 52 and 53 which era attached at spaced interval· to the link· of the respective chain. The rollers 52, S3 ride on elongated circular tracks 56, 58, respectively. The elongated circular tracks - IS IE 921503 56« 58 ax· disposed such that the cleats 46 and 50 rid* lnoagaging relationship for. a predeteni&ed interval (dlscuased la nor* detail below).

Preforably the web of .cheese in the tubular Sila ie- conveyed through the opposed Jaw* 44, 50 of the ••ling Mberi 42« 44 sudh that a hermetic seal i* foraed- between the two Inoar layer* of the web eater ini.· Mora preferably/ the eeal 1* forned such that when after-the. eeal baa been made and the package is pulled'-apaxt at the seal, the seel will break, ltd* 1» opposed to the eeala which are presently nade wherein after the seal h*s been forned and the package ie pulled apart, the seal is broken by delaainatlon, that io, by breaking the bond between the top non-sealing layer of and the inner or sealing layer of the sheet of the web. this preferred packaging arrangement 1* achieved by proper eelootion of· the themoplastle naterlal. VPr axaspla, one preferred eatarial conprleee « polypropylene layer coextruded with a polyethylene eealeat layer with an lsteteadlate edheelve layer.

In a preferred embodiment, the sealing tenperature is between 240*y and 280*P and the jaws travel with the web fro· the first point of engagement to the point of dieengageswnt for approximately one second. The pressure exerted between the two opposing javo on the sealing section 106 la Such that substantially all of the cheese is removed fron between the two layers of the thermoplastic web satsrial in the cross-sealed areas.

Suitable means are provided for driving the two chain arrangements In uw sealing motors 42 and 44. The slice* of cheese ar* defined in the section between th* jaws. Preferably, th* sealing section of the jaws 46 and 50 are auch that the cross seal 102 - 14 i - IS between adjacent cheese. el Ice· 10O 1· approximately 1/4 o£ an inch. She cleat·: 44. 50 are spaced in their respective chain· each .that the distance froa the beginning of «μ allce to the beginning of the next •lice (including the croee-seal aectlcaa 102) ie approximately 3-1/2 inches.

- This arrangement allow· for high speed production of the individual eliaaa of cheese 100.

Slnae the. heating cleets 66 and the abating 50 ride or aov· along with the cross aeal for a fixed period of tine, tbe web nay be continuously moved at a relatively fast pace providing a rapid production rate, for exaaple, the web nay be swved et agpromimmtely 300 feet/sinote or such that over approximately 1,000 slice* are produced per minute.

AMD-gPlCMm AwawawEMT After tiie eroaa Mala 102 have been formed, the web is then conveyed ‘to · cutting station 52. Loop control mean· 43 and tansioning mean· 47 are. elao provided. Referring specifically to Figs. 5 and 7, the cutting station include* · pair of spindlee 64, 66 with aeon· for severing the web at the cross aeele such that individual slice· ere defined. After the web bee been cut to form the individual slice·, tbe slices of cheese 100 are ready to ba stacked into individual stack* for packaging. The slices 100 are discharged froa the cutting section 62 and disposed on the stacker 70. Referring now specifically to figs. 4 and 7, a preferred embodiment of the stacker of tbe present invention is disclosed. She stacker 70 provide· an efficient v*y for selectively stacking e predetermined number of the cheese slices 100 being produced by the previously di*** cussed forming, seeling and cutting arrangement into · plurality of stacks.

J - 16 Bm stacking arrangement 70 comprises porous conveyor belt» which 1» preferably in tha form of an endless bolt'72. 'Preferably, tha endless belt 72 include a plurality of apertures-such that the belt 72 is approximately 25% or- more open, λ vacuum system 78 is provided on the inside of th· endless belt 72 such that the slices of cbeeee 100 are Maintained on the outside surface of the endless belt 72 by the atmospheric pressure differential pressure created by the vacuum system 79» Preferably the endless belt 72 rotates about two rollers or drums 74 and 74 which ere rotated by means known in the art. The vacuum system 78 provides sufficient vacuum sueh that the slices of cheese 100 adhere to the surface of the belt 72 as the belt Is advanced. That is. tha slices of cheese 100 are maintained on the belt as tha belt travels around tha drum. 76 and further are maintained even in aa upside down position as the slices 100 travel eround and are disposed on the bottom of the stacker 70. Thus, the vacuum of* the vacuum system 78 is sufficient to overcome the force of gravity pulling the slice of cheese 100 down when it is on the bottom of the belt 72.

A plurality of stacking locations 82a-82f axe provided to accommodate the rapid production rate of the wrapping system described above.

An air ejector 80a-80f la provided at the front of each stacking location 82a-82f. The air ejector COa-BOf, when actuated, applies air pressure at the leading edge of the ohaese slice 100 as It travels on tha bait 72. The ejector 80a-90f provides tha* positive air pressure through the apertures of the belt ee the slice passes under it to thereby override the vacuum and peel off” the eheeee elice 100 ea it is being conveyed past the ejector 80a~80f, in thia meaner, tha force of gravity releases the slice 100 into the desired - 17 IE 921503 stacking location. Preferably, «& Inclined plat· or reap plat·* 90 la ptowided before the front edge of each stacking.location 82a-82f. This reap plat· 90 assures that If tha cheese alloc 100 la released iron the conveyor bait 70 before It la folly In tha stacking location, tha cheese slice 100 will «110· onto the plata 90 and * ba conveyed Into tb· stacking location, λ photo sensor 84 Is provided at tha beginning of tha stacking location for progressing the auabor of sliest 100 to ba dropped at.each stacking location 83.

In a preferred embodiment, a particularly advantageous stacking system is configured such that an Intermadlato allea receiving means Is used to temporarily hold the first few slices being dropped into tha stacking location 82. Zn one preferred embodiment, the Intermediate sue· receiving mean· comprise» · first or uppar set of retractable fingerlike members 84. Preferably, a lower oat of retractable fingerllkn member· 88 era also provided.

Tha vppn eat of retractable finger· 84 are disposed at an intermediate level between the top of the particular stacking location and tha bottom of the stacking location. Cds upper set of stacking fingers 84 acta as an intermediate landing etop for the cheese allces 100 as they are peeled off Into the particular stacking location. After a predetermined nunbar of -slices have fallen on to the upper set of fingers 84, the fingers 84 are retracted such that the olicce of cheese 100 which were stacked In the particular stacking locations fall onto tbs lower sat of finger· 88. Tha lower set of fingers 88 la particularly important where the number of slices 100 that Is to he stacked In each stacking location Is large. Tor example, some projects may require as much as a four Inch stack of slice· ot cheese 100. The advantages of the upper set of fingers ιβ M are beat illuatrstedby describing the trajectory of the cheese ellcee-lOO.lf thia upper eeit of retractable fingers 8β «ere not present. Aa tbe elice 100 would ba pealed off by the ejector BO, the slice 100 would begin to fall at an angle with the leading edge of the elice 100 having the lowest position. If the elice 100 were to fell a sufficient distance, it would tuable rather* than being flatly deposited in sn orderly fashion thereby‘disrupting the stacking process. The upper fingers 88-provide an intermediate stop for the slices 100. The slice 100 only fella a short distance to the upper set of finger 88. Thus, the stability of the stack is maintained.

After e nuaber of loo slices have been disposed on to the upper aet of fingers 88, the upper retractable fingers 88 are retracted and the entire stack of slices 100 falls onto the lower sat of retractable fingers 88. Since a sober of slices 100 have already been deposited on tbs stack, tbe slices 100 which·are now being- peeled off from the conveyor 73 and dropped onto the «dating stack of slices 100 will have a shorter distance co fall. lhat la, the distance that a falling slice 100 will have to fell will only be the distance between the conveyor belt 70 and the top of tbe stack. After all of the slices j.00 that are to be included in a particular stack have been stacked, the lower set of retractable fingers 88 is retracted and the stack of slices 100 falls onto the conveyor table 82.

In another preferred «mbodieeirt, the intermediate slice receiving meena nay comprise an elevator arrangement which ie Initially raised to a predetermined intermediate height and is lowered to accomodate the rata at which the slices are being - IB stacked in the.stacking location·. frefsrably, In this eabodistent, theelevator is. lowered to deliver the stack to a conveyor table. 92 after the last slice 10O has been dropped in the stack.

Preferably neana such as s programmable controller or Microprocessor are operatively connected to th· respective ejectors 8Oa-80f at each stacking location 82a-62f such that the number of slices 100 in the Stacks 82a-82f can be eelectively adjusted. The controlling aeans will also make it possible to only fill certain stacking leoatiooa and ellsdnste other •tacking locations. In one particularly advantageous embodiment, the ejector· SOa-Bof and the control aeans •re operatively configured such that each stacking location 82a through 82f is successively or sequentially filled. In this eobodlaent, before any of the stacking locations 82a*-82f have been filled, all of the ejectors provide positive pressure at the front edge of each stacking location . Aa the elice 100 is conveyed pest the first ejector 80 (corresponding to the first stacking location 82a), the first ejector 80 provides positive pressure to peel the slice 100 off the conveyor belt 72 and into the first stacking location 82a. After the predeterained nuriber of slices 100 have been dropped into the first stocking location 82a, the positive pressure provided by the ejector Means 80a at the first stacking location ie terminated. Thus, the vacuua pressure froe the vacuum aeans 78 will continue to hold the next slice loo on the conveyor belt 72 until it reaches the ejector 80a at the second stacking location 82b. The ejector 80b at the second stacking location 82b will continue to operate until the second stack has been filled with tbe predeterained number of slices. After the second stack has been filled, the ejector 80b at the beginning of the second stacking location 82b will be turned off f sj and- thus tha nurt allca 100. will ba conveyed to the third'stacking location 82c. 2Ms preoess will continue until, the predetermined inpBor of slice· for each stacking location io complete. Thia proc··· lo particularly·, advantsgeous ainsa tha vaevua system does not.have to bo repeatedly disengaged. The air ejectors override ths-vacuum without the need co discontinue its operations. ·,·-. t Preferably, a· Illustrated in rigs. 1 and 5, tha stacks from each individual location 82a through 82 f are disposed onto another conveyor 93 which ia disposed such that it advances in a direction transverse to the direction of eovamrnt of the endless belt 72 of tbs stacker 70. Tn this Banner, the stacks of the slice· 100 are conveyed sway fro· ths stacker 72 to a location wbare they nay be further processed either manually or -automatically. therefore, the packaging and stacking systam of tha present Invention provide a mean· for hermetically packaging individual slice· of cheese at an efficient and rapid production rate, the sealing arrangament provided by the present invention provides a hematic oaal along the longitudinal edge of the web. After the cheese la inserted in the tubular web .hermetically sealed oross sosle are formed. This arrangement provides a hermetioally sealed package of ehaeao which will have a substantially longer shelf Ufa than the presently available sliced cheeae products. Additionally, the longitudinal seal and the cross swale are provided in a manner which permits continuous movement of ths web without the intermittent action of some presently available sealing systems.

Tha allca which is produced end packaged according to the present invention provide· a preferred final packaged product. The seal is formed between the two -ΙΟΙ inner layer· of the .low thermal malt material each that the seal ie broken when the packaging material· ere pulled apart to open the Individual slice, onllke presently available package·/ wberein the seeling layer is delealneted from the top layer of the packaging Material and when the package la epened a rough tear is aade whioh lead· to stringing*. Pith the package of tha prSsent' invention, the bond la broken between the two sealing layers of polyethylene end a nice clean opening is provided which eliminate the stringing problem.

Additionally, since the polyethylene nay bo need as the sealing layer, the packaging aaterlal la easily released from the processed eheeeo. fids obviates the need for items such as a shear pomp to process the cheese so as to have a less cohesive texture end provide a better role···: She process and apparatus of the present invention also permit the top layer of the packaging material to bo made of a polypropylene aaterlal. -Xhisis particularly advantageous since polypropylene le lose expensive then presently used material· snch as MYLAfc. fiw present invention also provides an efficient stacker which takes slices produced by a relatively rapid production machine and stacks the . slices In a plurality of stacks. She mndmr of alioes may he selectively varied in the stacking locations allowing for greater control la the production process.

She foregoing description of the preferred embodlnente of the present invention has boon presented for purposes of illustration and description. The described ibadlw nts are not intended te be exhaustive or to limit the invention to the precise form disclosed. obviously many modifications and variations are possible in light of the above teachings. The - tt eabodlnenta which vara described ware cboaen ia order to beat explain th· principles of the invention and its practical application*.' it is intended that the scop· of the invention ba defined by the following elains. including all equivalents. ¢921503 V,

Claims (22)

1. In a process for packaging a food Item formed Into a soft nass wherein the food ltea Is wrapped in individual slices, the improvement ccmgwlsingt folding a continuous web of heat-sealable tbentoplastlc eateri el into V-felded condition including a folded longitudinal side and an open longitudinal side; continuously moving the wab In a forward direction; continuously forming hermetic meal along the open longitudinal side of tbe web In V-folded condition to define a continuous tabular mb; inserting the food Item into the tubular web; after the food item is Inserted, continuously flattening the web to form a continuous slice of the food item disposed between a top layer and a bottom layer of tha web; forming a plurality of hermetically sealed cross-seals at predetermined intervale in the flattened web while tbe web la continuously moved forward, whereby hermetically sealed slices of tbe food item are defined.

2. - ihe precess of claim 1 Wbsrein the step of forming the hermetically sealed cross-seal comprises: arranging a first endless chain including a plurality of sealing mmdbers disposed thereon and a second endless chain including a plurality of smaling members disposed thereon such that the seeling meidbora on the first and second endless chains are opposed and ride in aligned relationship for e fixed distance; - 23 i 24 introducing the flattened web between the sealing members on the first and second endless chains) while tbe seeling eeebers on the first and second endless Chains are in aligned relationship, applying pressure to tbe eealing members to urge tbe opposed eealing mesbsrs such that the top and bottom layers of the web ere urged together) applying heat to at least one of the sealing members, the applied beat being sufficient to beat the sealing members to a temperature sufficient to meal tbs top sad bottom layers of tbe thermoplastic web at the eppiled pressure) moving the sealing masbers in tho aligned position for a sufficient time for tbe top and bottom layers of tbe web to form a hermetic seal at the applied pressure and heat.

3. The method of claim 1 wherein the step of forming a hermetic seal along tbe longitudinal side of the veb-includes) arranging a pair of plates, each having an undulating surface, such that the plates have opposed undulating surfaces with e predetermined fixed space between tho opposed surfaces of tbe plates, tbe plates defining a longitudinal sealing station) conveying the web of beat-sealable thermoplastic to tbe longitudinal sealing station) introducing the longitudinal open side of the v-foided web in the space between tho undulating surfaces of tbe plates) beating the plates to a toperaturs sufficient to seal the front and rear sheets of the vet; and continuously moving the web between tbe plates such that tbs front end rear sheets are brought into contact and a hermetic seal is formed. - 24 IE 921503

4. The proc·»» of- alii* 1 wherein the thetnopleetic material cemrlsas a polypropylene sealant layer. ..-*>-.···

5. The process cf clein ί farther cosprislng the step of cooling-tha food ites in tbs wab, the cooling stop being performed, between the step of flattening the web end the step of foming the hematic cross-seals.

6. · In a-process-for packaging a food Itea wherein the food itea ia wrapped in individual slices by inserting food itea into a- continuous plastic web. the iaproveasnt cosprislng foxaing a continuous tubular web of heat sealable therwoplaetic includingi arranging a pair of plates, each having an undulating surface, such that tbs pistes have opposed uudulating surfaces with a prsdeterainsd fixed space between the opposed surfaces of the plates, the plates defining a longitudinal sealing station; conveying a web of heat-sealable thernoplsstic, eoaprlsing a front sheet and e rear sheet in V-folded condition, to the longitudinal sealing station; introducing the longitudinal open end of the v*-folded web in the space between undulating surfaces of the plates; basting the plates to a teapersture sufficient to hemetically seel the front end rear sheets of the webtogether; end continuously Moving the v»b between the plates such that the front and rear sheets ere brought into contact and a hematic seel is fomed along the longitudinal section of the web. 25 IE 921503

7. The precess of claim 4 wherein th· thermoplastic aatarial comprises v a'polypropylene sealant layer. . t · - . · -··«·· . . .

8. She process of claim a, further comprising the steps ofi forming a good item into a soft messi • « inserting the «oft mass food Item into the tubular web of plastic; owing the web continuously in a forward ' direction; continuously flattening the Web with tbe inserted food item aueh that a continuous slice of the food its· io formed betwaan top and bottom layers of the plastic web; after tho web has bean flattened, urging the top and bottom layers of tho wsb .into intimate contact with each other at a plurality of cross-sealing sones while the web Is continuously moved forward: applying beat to tbs cross-sealing sones; tbe top and bottom layers of tho web being - * urged et a sufficient pressure to remove substantially all of the cheese therebetween and tbs bast being applied at a sufficient temperature and for a sufficient length of time to form a hermetic beat seal between the top and bottom layers of thermoplastic material, whereby slices of the food item are defined between adjacent contacting xones of tbe web.

9. Tho process of claim 1 further wwprislng the step of cooling the food Item in tbe web. tho booling step being performed between tbe atop of flattening the web and tbe step of urging tbe top and bottom layers of the web into intimate contact with eaoh other ot plurality of cross-ssallng sones. - 27 IE 921503 ,ip., . process ot claim 2 wherein the steps of urging the top end bottom layers of the web «ad applying heat te ths contacting pones of the web conpriset arranging s first endless chain including a plurality of scaling members disposed thereon and a second endless chain Including a plurality of sealing msmbere disposed thereon such that the sealing ambers on the first and second endless chains are opposed and ride ln aligned relationship for a fixed distance; introducing the flattened vrt between the sealing aasbers on the first and second endless chains; while the seeling sssbers on tba first and second endless chains are in aligned relationship, applying pressure to the sealing Bashers te urge the opposed sealing aaahsrs such that the top and bottcn layers of ths wsb are urged together; ^plying hast to at least one of the sealing members, the applied heat being sufficient to heat the sealing aeabars to a temperature sufficient to seal the top and botton layers of the tfaeraoplastio web at the applied pressure; moving the sealing members in the aligned position for * sufficient tine for the top and botton layers of the web to font a hematic seal at the applied pressure and heat.

10. 11. In an apparatus for packaging a food its· wherein food itaa is wrapped in individual siloes including means for foraing the food item into a soft mass, naans for inserting the food item into a continuous tubular web of plastic material and mssns for continuously flattening the with the inserted food itsn euch that the a continuous slice of the food item la defined between top layer and .a bottom layers of the tubular web, the improveaoxt comprising: beans Cor folding s continuous web of thermoplastic naterial into-V-folded condition including .e< top layer and a bottoa layer joined by a fold et the bottoa; a longitudinal. sealing station including, mane for continuously forming a hematic seel along the top. longitudinal section of the web as tho web io continuously served; . a- cross sealing station including noons for contlnuouslyvfomiag hermtlcally sealed erooe-aeala at predatezalned Intervale in the web aa the web ia continuously moved; and means for continuously conveying the web to tho longitudinal and' cross selling stations·

11. 12. Ihe apparatus of olein 11 wherein tho neans for foming tho longitudinal seal conprlees: a pair of fixed plates, each having an undulating aorfeoe, the plates disposed eueh that the plates have-opposed undulating surfaces with e prodetominod fixed apace between the opposed surfaces of the plates; mana for heating tho plates to a teaperature sufficient to fora a seal between the front end rear sheets of tho web; end Mens for continuously conveying the web between the spica between the plates such that the front and rear sheets are brought into oontaot so that the front and rear sheets are hansetically oealed together along tho longitudinal section of the web.

12. 13- The apparatus of date 11 wherein the man· for foning the croee-eeela conprleesι a first endless chain including a plurality of sealing raehera disposed thereon and mans for revolving the first endless chain; a second endless - 28 IE 921503 - 29 chain including a plurality of mealing member· disposed thereon and means for revolving the second endless chain,· the firmt and second endless ehaine being arranged sueh that for a predetermined interval, the sealing members of the first and second endless chains re opposed and ride in engaged relationship upon revolution of the first and second endless chains and such that the flattened web may be introduced between the opposed sealing Matters; -Man* for applying sufficient pressure to urge the two sealing wesber· towards each ether while in the engaged relationship such that, upon introduction of the flattened web between toe engaged sealing mssfcere, substantially all of the food item it removed between the top and bottom layers of toe web in toe engaging section; Mint for «plying heat to toe sealing members to heat the sealing membere to a temperature sufficient to fora a hermetic; seal between at least two layers of the web at the applied pressure.

13. 14. The apparatus of claim 19 wherein toe seeling members of one of toe first endless chain are comprised of a Mtellie material and the sealing members of toe second endleaa chain are comprised of a resilient material.

14. 15. The apparatus of claim 12 further including means for cooling the flattened web, the cooling weans being disposed between the longitudinal sealing station and the cross-sealing station.

15. 16. The apparatus of claim 12 further comprising means for selectively adjusting the amount of toe food item inserted .into toe tubular web.

16. 17. .The apparatus, of claim U wherein ths means for fopaing the longitudinal seal is configured such that the longitudinal seal is formed between tbe inner surfaces of the front and rear Sheets of the web.

17. 18- An apparatus for forming the longitudinal seal in a web in V-folded. condition eonprising; a pair of fixed plates, each having an undulating surface, the plates disposed such that the plates have-opposed undulating surfaces with a predetermined fixed epece between the opposed surfaces of the plates; mean· for heating the plates to a temperature sufficient to form a seal between the front and rear sheets of the web: and means for continuously conveying the web between the .space between the plates such that the front end rear sheets are brought into contact so that tbe front and rear sheets are hermetically sealed together along the longitudinal section of tho web.

18. 19. The apparatus of claim 18 wherein the mesas for heating the plates comprises an electrical heater. - 30 IE 921503 - 31

19. 20. A process for packaging a food item according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

20. 21. An apparatus for packaging a food item according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

21.

22. An apparatus for forming the longitudinal seal in a web in V-folded condition according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.