GB2179620A - Packaging and extrudable product - Google Patents

Abstract

In the manufacture of individually wrapped slices of processed cheese, a tube of film plastics material filled with a hot mass of cooked cheese is passed between a rotating vacuum wheel 17 and a contra-rotating pressure wheel 16 which subdivides the cheese in the tube into separate portions each in the shape of a thin slice with the parts of the tube between the portions compressed into flat webs, the tube is then passed between the rotating vacuum wheel and a contra-rotating cutter wheel 18 which severs the webs to divide the tube into separate sections each containing a thin portion of cheese still in an extrudable condition, and the sections are deposited on a conveyor for transport to a cooling chamber to solidify the cheese. The tube is held by vacuum against the vacuum wheel during passage from the pressure wheel to the conveyor. <IMAGE>

Description

SPECIFICATION Packaging of an extrudable product This invention relates to the packaging of an extrudable product in flexible sheet material to provide in dividuallywrapped portionsofthe product, and is concerned more particularly but not exclusively to the packaging of an extrudable food productwhich can subsequently be solidified, cooked or otherwise processed in individually wrapped portions.

The invention is particularly applicable to the wrapping of portions of a hot cooked cheese mass in the manufacture of individually wrapped slices of processed cheese and the invention will be descri bed with reference to this application.

In a known method of manufacturing individually wrapped slices of processed cheese, a hot mass of cooked cheese which is in a viscous state is extruded continuouslythrough a nozzlewhileatubeoffilmlike heat-sealable sheet material is continuously formed around the nozzle for reception ofthe viscous cheese mass, and the moving filled tube is immediately shaped in the gap between two opposing endless belt formers to su b-divide the cheese mass in the tube into flat portions of equal size spaced along the tube. The shaped tube is then fed between two wheel formers having cooperating heating anvilswhich heat-seal the opposing walls ofthe parts of the tube between the portions of cheese mass so as to form sealed pockets in the tube with each pocket filled completely with a separate portion ofthe cheese in the shape of a thin slice.The shaped tube is then fed through a cooling chamber two solidify the portions of the viscous cheese mass into solid slices of processed cheese, and the shaped tube subsequently fed to rotary cutters operable to cut the tube through the heat-sealed parts thereof so as to form sealed packets each containing a slice of processed cheese.

In the commercial manufacture of individually wrapped slices of processed cheese, the apparatus runs at high speed, for example 600 slices a minute, and the shaped tube extending through the cooling chamber between the heat-sealing wheel formers and the cutters may have a length corresponding to 500 slices or more.It is very difficult to synchronise operation ofthe cutters with the moving tube so as to cut the tube accu rately across the middle of the sealed parts ofthe tube between the slices of cheese due to variation in the stretch ofthe tube. Iffor ex- ample the section oftube containing each slice stretched by0.5mmduring passagethroughthecooling chamber, it would be necessaryto allow for a total stretch of 250 mm for a length of tube corresponding to 500 slices.

According to the present invention there is provided a method of packaging an extrudable product in flexible sheet material to provide individually wrapped portions ofthe product, comprising extruding the product through a nozzle, forming a tube of said sheet material around the nozzle for reception of the extruded product so as to provide a tube filled with the product, shaping the filled tube to subdivide the product in the tube into portions spaced apart along the tube, and subsequently severing the tube between said portions, wherein the filled tube is shaped by opposing formers which compress the parts of the tube between said portions into flat webs consisting ofthe opposing walls ofthetube, and the flat webs are then severed to divide the tube into sep arate sections each containing one of said portions of the productwhilethe product is in an extrudablecon dition.

In the method of the invention each wrapped portion ofthe extrudable product is enclosed in a section ofthetubewhich is not sealed at its ends. It will of course be necessaryto handlethewrapped product by equipment which does not squeeze the product since otherwise the product would be extruded through the ends ofthe tube section. The wrapped portions or slices of the product are preferably conveyed by endless belt conveyors through processing apparatus, which may for example cool the product to solidify it as in the manufacture of slices of processed cheese from a hot cooked cheese mass, or heatthe product as in the manufacture of cooked meats.

Thus, according to the invention there is also provided a method of packaging and processing an extrudable product in flexible sheet material, comprising extruding the product through a nozzle, forming a tube of said sheet material around the nozzle for reception of the extruded product so asto provide a tube filled with the product, shaping the filled tube to sub-dividethe product in the tube into portions spaced apart along the tube, and processing the product in the tube, wherein the filled tube is shaped by opposing formers which compress the parts of the tube between said portions into flat webs consisting of the opposing walls of the tube, and the flat webs are sev ered to dividethetube into separate sections each containing one of said portions of the product prior to the processing of the product.

In the method of the invention, the shaped tube preferably remains in engagement with a second of the formers for movement therewith aftertheformation of the flat webs in the filled tube, and the flat webs severed while in engagement with the second former. Theflatwebs of the shaped tube can conveniently be severed by passing the shaped tube between the second former and a third former coop- erating with the second formerto maintain the shape ofthe portions and severthe flat webs.

The shaped tube can conveniently be held in en gagementwiththeabove mentionedsecondformer by vacuum Inan arrangement in which the tube is formed by drawing a web of the sheet material through a tube former surrounding the nozzle, the pull required for drawing the web through the tube former can be provided by the entrainment of the shaped tube bythe vacuum to the second former.

Apparatus for packaging a hot cooked mass of cheese in accordance with the method ofthe invention, in the manufacture of individually wrapped slices of processed cheese, will now be described, by way of example, with reference to the accompany drawings, in which: Figure lisa diagrammatical representation ofthe apparatus, and Figure2 is a view taken in the direction of the arrow A in Figure 1.

The apparatus shown in the drawings comprises an extruder 10, a tube former 11 adapted to fold a web 12 offilm-like heat-sealable plastics sheet material into a tube 13 for reception of cheese extruded from the extruder, the web 12 being drawn from a roller ofthe material, a sealing iron 1 Sforheat- sealing overlapping margins ofthe web 12 when formed intothetube 13,a pressure wheel 16,a vacuum wheel 17, a cutter wheel 18, and an endless belt conveyor 19 The extruder 10,tubeformer 11 and sealing iron 15 are of conventional construction well known in the artand will therefore only bedescribed briefly.

The extruder 10 comprises a tubularsocket 25 fitted with a nozzle 26formed from a long circularsec- tion tube which is flattened into an oval section a short distance from the socket, the socket and nozzle being supported on a beam 27 (Figure 2) with the nozzle 26 projecting vertically downwards.The web 12 extendsfrom the roll 14, around the underside of a guide roller 30 adjustably mounted on two support rods3l,andthenextendsupwardlytothetube former 11 The tube former comprises a cowl 32 (Figure 2) mounted on a frame 33 suspended by rods 34 from the beam 27,the cowl surrounding but spaced from the nozzle 26 and arranged to guide and fold the web 12 around the nozzle with the margins ofthe web overlapping in the longitudinal direction of the nozzle 26so as to form the tube 13. The tube 13 is a loose fit around the nozzle 26so as to be free to slide along the nozzle. The sealing iron 15 comprises an electrically heated plate 35 extending along the nozzle 26.The plate 35 is pivotally connected to a system of levers 36 mounted on the frame 33 and connected to a spring (not shown) which urges the plate 35 towards the nozzle. The sealing iron is arranged so thatthe overlapping margins ofthe web 12 are lightly clamped between the electrically heated plate 35 and the nozzle 26 so asto effect heat-sealing of the overlapping margins.

The pressure wheel 16 comprises a rotatable frame (not shown) having a cylindrical outer rim 45 formed with transverse slots 46 spaced at equal intervals around the rim, and a plurality of rectangular housings 47 welded to the inside surface of the rim 45, each housing 47 being aligned with a separate slot46. Each housing 47 contains a stainless steel plunger48, a spring 49, and a spring adjuster 50. The plunger48 has a narrow rectangular nose portion which extends as a close sliding fitthrough the associated slot 46 and projects a short distance beyond the outer surface ofthe rim 45 when the plun ger is engaged against the inner surface of the rim, the nose portion serving as an anvil 51 as described hereinafter.The spring adjuster 50 comprises a screw-threaded rod 52 engaged in a screw-threaded aperture in the radially inner end ofthe housing, a spring abutment 53 on the end of the rod 52 inside the housing, and a handle 54 on the end ofthe rod outside the housing. The spring 49 is compressed between the abutment 53 and the plunger48, the spring urging the plunger radially outwards with a force which can be adjusted by the handle of the screw adjuster.

The vacuum wheel 17 comprises a rotatable frame (not shown) having a cylindrical outer rim 60 ofthe same diameter as that of the rim 45 of the pressure wheel 16, and a plurality of rectangular anvils 61 of high density polyurethane mounted in transverse grooves in the outer surface of the rim 60, the anvils 61 having a length and width equal to the length and width respectively ofthe anvils 51 on the pressure wheel, and the anvils 61 being spaced apart around the outer rim 60 atthe same equal distances as the anvils 51 are spaced around the outerrim 45 ofthe pressure wheel.The inside ofthe rim 60 is fitted with a plurality of sheet metal casings 62 each ofwhich cooperates with the portion ofthe outer rim 60 between two adjacent anvils 61 to define a vacuum chamber 63, the outer rim being provided with a plurality apertures 64 which open into the vacuum chambers. The vacuum wheel is also fitted with a hub plate having ports (not shown) spaced around a circle co-axial with the axis of rotation of the vacuum wheel, and pipes 67 each connecting one ofthe ports with aseparatevacuum chamber63.Thehub plateis in sliding contact with a non-rotatablevalve plate 68 having an arcuate suction port 69 and a vent port70 arranged to register with each of the ports in the hub plate in turn upon rotation ofthe vacuum wheel.The valve plate is urged axially by springs (not shown) into sliding contact with the hub plate, and means are provided to lubricate the sliding surfaces on the two plates.

The cutter wheel 18 comprises a rotatable frame (not shown) having a cylindrical outer rim 75 ofthe samediameterasthatofthe rim 60 ofthevacuum wheel 17, and a plurality of rectangular blade holders 76 mounted in rectangular recesses 77 in the outer rim 75, the blade holders 76 having a length and width equal to the length and width respectively of the anvils 61 in the vacuum wheel, and the blade holders 76 being spaced apartaroundthe rim 75 atthe same equal distances as the anvils 61 are spaced around the rim 60 ofthe vacuum wheel. The blade holders 76 are clamped in position in the recesses 77 by screws 78 which project through the side walls of the recesses.Each blade holder 76 is fitted with a cutting blade 79 which extends along the full length of the holder 76 and parallel to the axis of rotation ofthe cutterwheel,the blade projecting radially outwards beyond the radially outer surface ofthe holder 76.

The vacuum wheel 17 is mounted on a spindle 85 which is rotatably mounted in a fixed bearing (not shown). The pressure wheel 16 is mounted on a spindle 86 which is parallel to the spindle 85 and rotatably mounted in a bearing block 87 movable in a slideway 88 towards and away from the spindle of the vacuum wheel 17. The position of the bearing block 87 in its slideway 88 is adjustable by two screw threaded bolts 89,90 engaging opposite ends ofthe bearing block 87. The cutterwheel 18 is mounted on a spindle 94 which is parallel to the spindle 85 ofthe vacuum wheel and rotatably mounted in a bearing block 95 movable in a slideway 96 towards and away from the spindle ofthevacuum wheel 17.Theposi- tion of the bearing block 95 in the slideway 96 is adjustable bytwo screw threaded bolts 97, 98 engaging opposite ends ofthe bearing block 95. The pressure wheel 16, the vacuum wheel 17 and the cutter wheel 18 are thus all rotatably mounted about parallel axes, and the wheels are arranged so that they lie in a common radial plane ofthethree axes.The spacing between the wheels 16,17 and the spacing between the wheels 17, 18 are adjustable by movement of the bearing blocks 87,95 in their respective slideways in order to vary the thickness of the slices of processed cheese to be produced by the apparatus, as hereinafter described.

The pressure wheel 16 and the vacuum wheel 17 are positioned alongside one another with the gap therebetween directly below the lower end ofthe nozzle 26 ofthe extruder and with their cylindrical outer rims 45,60 spaced apart a distance equal to the thickness of the slice of processed cheese to be produced by the apparatus. The cutter wheel 18 is positioned directly below the vacuum wheel 18 with the cylindrical outer rims 60,75 ofthe two wheels also spaced apart at a distance equal to the thickness of the slice of processed cheese to be produced. The belt conveyor 19 is arranged to receive the individually wrapped portions of the cheese mass emerging from the gap between the vacuum wheel and the cutterwheel, as hereinbefore described.

The pressure wheel 16 and the vacuum wheel 17 are drivably connected to one another by gearing (notshown)for rotation in opposite directions atthe same speed, the two wheels being arranged so that each ofthe anvils 61 on the vacuum wheel 17 abuts against a corresponding anvil 51 on the pressure wheel 16 upon rotation of the two wheels 16, 17. The anvils 51,61, project above the outer rims 45, of their associated wheels by a distance such that, when the wheels are adjusted to the maximum spacing apart, the anvils 51 are pressed radially inwards a short distance againstthe action of their springs 49 when the anvils 51,61 are in full abutting contact.The vacuum wheel l7andthecutterwheel 18arealso drivably connected to one another by gearing (not shown) for rotation in opposite directions at the same speed, the vacuum wheel 17 and the cutter wheel 18 being arranged so that each of the blade holders 76 on the cutter wheel abuts against a corresponding anvil 61 on the vacuum wheel 17. The fixed valve plate 68 for the vacuum wheel 17 is arranged so that, at any rotational setting of the vacuum wheel, only the tubes 67 forthe vacuum chambers 63 underlying the part of the rim 60 extending between thewheel 16 and the belt conveyor 19 intheanti- clockwise direction as shown in Figure 1 are in registerwith the suction port 69.Only the tube 67 forthe vacuum chamber 63 underlying the part of the rim 60 which is directly above the belt conveyor 19 is in registew with the vent port 70.

In operation, the vacuum wheel 17 is rotated at constant speed in an anti-clockwise direction as viewed in Figure 1, the pressure wheel 16 and the cutterwheel 18 being driven by the associated gearing at the same speed in the clockwise direction, a vacuum is applied to the port 69 in the valve plate 68, the tube 13 is fed between the wheels 16, and then between the wheels 17, 18 and hot cooked cheese is extruded continuously through the nozzle 26 into the tube. A reservoir 82 of the cheese collects in the tube 13 immediately abovethe two wheels 16,17 and the two wheels compress the filled tube to a thickness determined by the spacing between the two wheels.

The cheese in the parts of the tube between the abutting anvils 51,61 is squeezed back into the reservoir 82, so that the cheese in the shaped tube emerging from between the two wheels 16,17 is divided into equal portions with the parts of the tube between the portions of cheese pressed into flat webs. The shaped tube is held against the periphery ofthe wheel 17 bythevacuum intheapertures64and chambers 63 which are connected by the tubes 67to the vacuum port 69, and the entrainment ofthe shaped tube to the wheel 17 by the vacuum provides the pull in thetube necessaryfor drawing theweb 12 of sheet material through the tube former 11.When the shaped tube passes between thevacuum wheel 17 and the cutter wheel 18, the flat webs are again compressed between the anvils 61 and the blade holders 76, and the blades 79 sever the flat webs centrally across theirfull width, so that the shaped tube is divided into sections each containing a portion ofthe hot cheese. Each section of tube containing the portion of cheese is held against the periphery ofthe wheel 17 by the vacuum in the underlying chamber until the section of tube is above the belt conveyor 19.

The tube 67 forthe underlying vacuum chamber is then in register with the vent port 70, so that the vacuum is released and the section oftube contain- ing the cheese portion drops onto the conveyor. The sections of tube containing the cheese portions are transferred by the belt conveyor to a cooling chamber where the cheese is solidified.

The apparatus shown in the drawings may be used forthe packaging of portions of a prepared meat emulsion or any other viscous, granular or minced product which can be extruded. The pressure necessary to squeeze outthe product from between the abutting anvils on the wheels 16, 17will depend on the viscosity ofthe product and can be adjusted bythe handles 54 on the pressure wheel 16. The springs 49 and screw adjusters 50 may, if desired, be replaced by blocks of resilient material such as solid gum rubber or a resilient plastics.

The ends of the sections of tube filled with portions of a product in accordance with the method ofthe invention are not sealed, but are nevertheless closed by the opposing walls ofthe tube being pressured together. Such a closure will exclude air, but can easily be opened by squeezing the tube so asto force the product out of the ends ofthe tube. The opposing walls at the ends ofthe tube sections may if desired be tacked together by piercing and folding small por tions ofthe overlapping walls ofthetube, by the equipment in common use fortacking paper sheets together. The tacking operation may be carried out by additional cutters fitted to the blade holders on the cutterwheel 18.

It will be appreciated that the drawings show only a diagrammatic representation of apparatus for carrying out the method of the invention as defined in the attached claims, and that the components of the apparatus may be of any suitable construction for this purpose.

Claims (17)

1. A method of packaging an extrudable product in flexible sheet material to provide individually wrapped portions of the product, comprising extruding the product through a nozzle, forming a tube of said sheet material around the nozzle for reception of the extruded product so as to provide a tubefilled with the product, shaping thefilled tube to subdivide the product in the tube into portions spaced apart along the tuber and subsequently severing the tube between said portions, wherein the filled tube is shaped by opposing formers which compress the parts ofthetube between said portions into flat webs consisting of the opposing walls ofthetube, and the flat webs are then severed to divide the tube into separate sections each containing one of said portions of the extrudable product while the product is in an extrudable condition.

2. A method of packaging and processing an extrudable product in flexible sheet material, comprising extruding the product through a nozzle, forming a tube of said sheet material around the nozzle for reception of the extruded product so as to provide a tube filled with the product, shaping the filled tube to sub-divide the product in the tube into portions spaced apart along the tube, and processing the product in the tube, wherein the filled tube is shaped by op posing formerswhich compress the parts of the tube between said portions into flat webs consisting of the opposing walls of the tube, and the flat webs are severed to divide the tube into separate sections each containing one of said portions ofthe product prior to the processing of the product.

3. A method as claimed in Claim 1 or Claim 2, wherein the shaped tube remains in engagement with one oftheformersfor movement therewith after the formation of the flat webs in the filled tube, and theflatwebsareseveredwhile in engagementwith said one former.

4. A method as claimed in Claim 3, wherein the shaped tube is passed between said one former and a cutting device having cutters cooperating with said oneformerto severtheflatwebsoftheshapedtube.

5. A method as claimed in Claim 3, wherein the shapedtube is passed between said oneformerand athird former cooperating with said one former to maintain the shape of said portions and to severthe flat webs ofthe shaped tube.

6. A method as claimed in any of Claims 1 - 5, wherein the shaped tube is held in engagement with said one former by vacuum.

7. A method as claimed in Claim 6, in which the tube is formed by drawing a web of the sheet mat erialthrough a tube formersurrounding the nozzle, wherein the pull required for drawing the web through the tube former is provided by entrainment of the shaped tube by said vacuum to said one former.

8. A method as claimed in any of claims 1 - 7, wherein the filled tube is shaped by passing the tube between the peripheries of two contra-rotating wheels having parallel axes and lying in a common radial plane ofthetwo axes, the peripheries ofthe wheels constituting said opposing formers.

9. A method as claimed in Claim 8, wherein the peripheries of said wheels have anvils which cooperate to compress said parts ofthetube into the flat webs upon rotation ofthewheels.

10. A method as claimed in Claim 8, wherein each of said wheels has a cylindrical peripheral surface and transverse anvils spaced at equal intervals around the wheels and projecting radially outwards from its peripheral surface, the anvils on the two wheels cooperating upon rotation on the two wheels in opposite directions to compress said parts ofthe tube into flat webs.

11. A method as claimed in Claim 10, wherein the two wheels are adjustable towards and awayfrom each other to vary the size of the gap between their peripheries and therebyvary the thickness of the product in the shaped tube, and the anvils on at least one of the wheels are movable radially inwards against the action of spring means.

12. A method as claimed in Claim 9, wherein the shaped tube is held by vacuum in engagementwith a second of said wheels after the formation of the flat webs in the shaped tube, and a cutter wheel rotates in synchronism with the second wheel and cooperates therewith to sever the flat webs of the shaped tube.

13. A method as claimed in Claim 12, wherein the separate sections of the filled tube are deposited on a conveyorfortransportto processing equipmentfor solidifying the wrapped portions of the extruded product.

14. A method as claimed in Claim 13,whereinthe extrudable product is a mass of hot cooked cheese, and the individually wrapped portions of the cheese mass are subsequently cooled to solidify the cheese mass into slices of processed cheese.

15. Apparatus for packaging an extrudable product in flexible sheet material to provide individually wrapped portions of the product, comprising an extruderfor extruding the productthrough a nozzle, a tube former for folding a web ofthe sheet material into a tube surrounding the nozzle for reception of the extruded product, a pressure wheel, a vacuum wheel and a cutter wheel, said wheels being rotatably mounted about parallel axes and lying in a common radial plane, and means for rotating the pressure wheel and the cutter wheel in synchronism with the vacuum wheel and in the opposite rotational direction thereto, the pressure wheel and the vacuum wheel being arranged to receive the filled tube in the gap between the peripheries thereof, the vacuum wheel and the cutter wheel being arranged to subsequently receive the filled tube in the gap between the peripheries thereof, the vacuum wheel being operable to hold the filled tube in engagement with its periphery by vacuum during passage of the filled tube between the pressure wheel and the cutter wheel, the periphery ofthe pressure wheel cooperating with the periphery ofthevacuumwheel to shape the filled tube by sub-dividing the product in thetube into portions spaced apart along the tube and to compress the parts ofthetube between said portions into flat webs consisting ofthe opposing walls ofthe tube, and the cutter wheel cooperating with the per iphery of the vacuum wheel to sever the flatwebs in the tube so as to divide the tube into separate sec tions each containing one of said portions ofthe extrudable product.

16. A method of packaging an extrudable product in flexible sheet material to provide individually wrapped portions of the product substantially as hereinbefore described with reference to the accompany drawings.

17. Apparatusforpackaging an extrudableproduct in flexible sheet material to provide individually wrapped portions ofthe product, substantially as herein before described with reference to the accompanying drawings.