Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B19/00—Packaging rod-shaped or tubular articles susceptible to damage by abrasion or pressure, e.g. cigarettes, cigars, macaroni, spaghetti, drinking straws or welding electrodes
  • B65B19/02—Packaging cigarettes
  • B65B19/22—Wrapping the cigarettes; Packaging the cigarettes in containers formed by folding wrapping material around formers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B53/00—Shrinking wrappers, containers, or container covers during or after packaging
  • B65B53/02—Shrinking wrappers, containers, or container covers during or after packaging by heat

Definitions

• the invention relates to a method and apparatus for shrink- wrapping containers and finds particular application in the shrink- wrapping of packs of smokable articles such as cigarettes.
• shrink wrap cigarette packs and other containers in an outer film of, for example, polypropylene.
• a stream of cigarette packs which are individually wrapped in a heat-shrinkable film is conveyed through a shrink tunnel where the packs are heat-treated by convection, using hot air, and/or conduction, using hot flat plates, in order to shrink the film wrappers around the packs.
• the individually wrapped cigarette packs are typically transferred cyclically from a piling or stacking station into the shrink tunnel in superimposed pairs .
• a reciprocating horizontal pusher transfers vertically stacked pairs of superimposed cigarette packs from the stacking station into the shrink tunnel, where the pairs of packs are pushed against one another to form a continuous stream.
• the cigarette packs are thus conveyed longitudinally through the shrink tunnel in two superimposed abutting rows with the upper faces of cigarette packs in the lower row in contact with the lower faces of cigarette packs in the upper row.
• the heat-shrinkable film in contact with these inaccessible faces of the cigarette packs is disadvantageously exposed to little or no heat within the shrink tunnel.
• US-B-6, 511, 405 discloses an apparatus for producing packs having an outer wrapper of improved appearance comprising a shrinking station with a top heating plate for applying heat to the upwardly directed front sides of packs in the top row and a bottom heating plate, positioned in the region between the two superimposed pack rows, for applying heat to the upwardly directed front sides of packs in the bottom row. So that they are conveyed through the shrinking station above the bottom heating plate, the packs of the top pack row are raised relative to the packs in the bottom pack row by a ramp in the region of the heating plates.
• an apparatus for shrink wrapping a plurality of individually wrapped containers comprising: a stacking station, a shrink tunnel, and a transfer device for transferring a pair of superimposed containers individually wrapped in a heat-shrinkable film from the stacking station to the shrink tunnel, characterised in that the transfer device is adapted to engage and separate the pair of superimposed containers and to convey the separated containers from the stacking station into the shrink tunnel.
• separation of the pair of superimposed containers by the transfer device rather than by a ramp or other hard repositioning means, not only renders the upper side or face and the lower side or face of each container accessible to one or more heating devices provided in the shrink tunnel, but also reduces or avoids the risk of the containers and/or their non-shrunken film wrappers being damaged as the containers are transferred to the shrinking station.
• the transfer device is adapted to apply a vacuum to a portion of the surface of at least one of the pair of superimposed containers distant from the shrink tunnel. More preferably, the transfer device is adapted to apply a vacuum to a trailing side or face of the uppermost one of the pair of superimposed containers.
• the transfer device comprises at least one suction plate or cup for engaging a portion of the surface of at least one of the pair of superimposed containers distant from the shrink tunnel.
• the at least one suction plate or cup is mounted on a pusher mounted for longitudinal movement relative to the shrink tunnel.
• the pusher is mounted on a carriage on a cam track.
• the shrink tunnel comprises at least one heating plate for applying heat to the film wrappers of the separated containers . More preferably, the shrink tunnel comprises an inner heating plate mounted between the separated containers for applying heat to opposed inward facing surfaces of the separated containers. Most preferably, the shrink tunnel comprises an inner heating plate mounted between the separated containers for applying heat to opposed inward facing surfaces of the separated containers and a pair of opposed, spaced apart, parallel outer heating plates for applying heat to outward facing surfaces of the separated containers .
• the inner heating plate is fixed, while, to reduce friction between the separated containers and the shrink tunnel, the outer heating plates are preferably adapted to move in sequence with the movement of the separated containers.
• the shrink tunnel may advantageously further comprise a second pair of opposed, spaced apart, parallel heating plates, substantially perpendicular to the inner heating plate and the pair of outer heating plates, for applying heat to corresponding further surfaces of the separated containers.
• the second pair of opposed, spaced apart, parallel heating plates is preferably also adapted to move in sequence with the movement of the separated containers in order to reduce friction.
• Any suitable known heating plates may be employed in the shrink tunnel of the apparatus of the invention, for example, heating plates heated by electric resistors.
• the apparatus of the present invention may further comprise means for, in use, supplying hot air into the shrink tunnel in order to shrink the film wrappers of the separated containers instead of or in addition to one or more heating plates.
• the transfer device utilizes negative pressure, applied, by way of a suction unit, to the trailing side or face of the uppermost container of a superimposed pair of containers formed in a vertical stacking station, to engage and lift the uppermost container vertically and thereby separate the pair of containers .
• a vacuum of between about 0.6 bar and about 1 bar is preferably applied by the transfer device to the - A - uppermost cigarette pack in order to separate the cigarette packs.
• the suction unit of the transfer device may, for example, comprise a suction plate including a plurality of holes or one or more suction cups through which, in use, a vacuum is drawn.
• the suction unit is preferably mounted on a horizontal pusher, which in turn is mounted on a carriage on a fixed cam track.
• a horizontal pusher which in turn is mounted on a carriage on a fixed cam track.
• the transfer device may alternatively also utilize negative pressure applied by way of a suction unit to engage the lowermost container of the superimposed pair of containers.
• a first container wrapped in a heat- shrinkable film is preferably lifted upwards to a pre-determined height in the stacking station by a reciprocating vertical pusher, where it is held in position in a known manner, while the pusher returns to its initial position.
• the vertical pusher then lifts a second container wrapped in a heat-shrinkable film upwards to the same pre-determined height in the stacking station where it is held in position with the lower face or side of the first container supported on the upper face or side of the second container.
• the engagement and separation of the thus formed pair of superimposed containers by the transfer device takes place directly after the superimposition of the containers, during the time taken by the vertical pusher to travel back to its original position to collect a container to form the first container of a subsequent pair of superimposed containers .
• medium and high speed shrink wrapping machines for cigarette packs operate with a rate of between about 400 to 600 packs per minute. Accordingly, where the preferred embodiment of the apparatus of the invention is used to shrink wrap cigarette packs, the carriage and hence horizontal pusher of the transfer device may, for example, operate at about half this rate.
• the transfer device is also provided with a supply of compressed air to blow the container or containers off of the suction unit into the shrink tunnel .
• the heating device delivers heat through at least one central heater plate located between the pair of separated superimposed containers. More preferably, the heating device delivers heat through at least one fixed horizontal heater plate located between the pair of separated superimposed containers, which also serves as a support or steering plate for at least one of the containers.
• the heating device may be of any suitable known type, for example, a plate heated by electric resistors .
• the shrink tunnel further comprises heating plates that move in sequence with the separated containers, that is, for example, vertically spaced apart, parallel top and bottom heating plates for heat treating the upper surface of the uppermost container and the lower surface of the lowermost container, respectively, that index up and down in time with the movement of containers directly underneath or over them respectively.
• the shrink tunnel of the preferred embodiment of the apparatus of the invention may further comprise two horizontally spaced apart, parallel side heating plates, perpendicular to the top and bottom plates, that move in sequence with the pair of separated superimposed containers for heating the side faces thereof.
• the height of the stacking station of the preferred embodiment of the apparatus of the present invention is preferably increased by about the height of one container compared to conventional stacking stations to about the height of three containers.
• the apparatus of the invention further comprises a pre-sealing unit mounted in a lower portion of the stacking station for, in use, point sealing opposed folded ends of the unshrunken film wrapper around the lowermost of the three containers therein.
• the pre- sealing unit comprises a pair of opposed hollow, reciprocating pneumatic cylinders mounted in opposite sides of the stacking station, which, in use, are heated with hot air.
• the pneumatic cylinders are preferably positioned to spot heat two points on opposed sides of the lowermost pack where, due to the manner in which heat-shrinkable film is conventionally folded around cigarette packs, five thicknesses of film are folded.
• the apparatus of the present invention further comprises a choke detection device mounted in the stacking station.
• the choke detection device comprises a pair of opposed spring-loaded fingers hingedly mounted on either side of the upper end or exit of the stacking station at right angles thereto.
• accidental insertion of an additional container into the stacking station forces the spring loaded fingers to pivot upwardly against the sides of the stacking station thereby generating, by way of a sensor, a signal for the apparatus to stop.
• the spring-loaded fingers also advantageously reduce bouncing of the individually wrapped containers as they are fed into the stacking station.
• one side of the stacking station of the apparatus of the invention is hinged to the remainder thereof in order to allow easy access to the interior stacking station to, for example, remove accidentally inserted additional containers .
• a method for shrink wrapping a plurality of individually wrapped containers comprising: stacking at least two containers individually wrapped in a heat shrinkable film in a stacking station to obtain a pair of superimposed containers, applying a vacuum to at least one of the pair of superimposed containers to separate the superimposed pair of containers, and transferring the separated containers into a shrink tunnel .
• the method comprises applying a vacuum to a trailing side or face of an uppermost one of the pair of superimposed containers .
• the method preferably comprises a vacuum of between about 0.6 bar and about 1 bar.
• the method of the invention further comprises applying heat to opposed inward facing surfaces of the separated containers in the shrink tunnel through a heating plate mounted between the separated containers.
• Figure 1 shows apparatus according to the invention comprises a stacking station 100 including a vertical stack of three individually wrapped cigarette packs 10, 11, and 12.
• Cigarette pack 10 is separated from pack 11 by the application of vacuum through suction plate 110 integrated into horizontal pusher 120. Packs 10 and 11 are pushed forward by horizontal pusher 120 into a longitudinal shrink tunnel 200 comprising a central heating plate 210. Arrow 98 indicates the upward movement of pack 10. Arrow 99 indicates the downstream movement of packs 10 and 11.
• the method and apparatus according to the invention find particular application in the production of packs or smokable articles such as cigarettes, especially in the production of hinge- lid cigarette packs having rounded and/or bevelled edges.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Packages (AREA)
• Wrapping Of Specific Fragile Articles (AREA)
• Basic Packing Technique (AREA)
• Containers And Plastic Fillers For Packaging (AREA)
• Closing Of Containers (AREA)

Priority Applications (2)

Applications Claiming Priority (3)

Publications (2)

Family

ID=34938764

Family Applications (2)

Family Applications Before (1)

Country Status (10)

Families Citing this family (5)

Family Cites Families (9)

• 2005
  • 2005-02-18 EP EP05101239A patent/EP1693298A1/de not_active Withdrawn
• 2006
  • 2006-02-17 JP JP2007555623A patent/JP4990800B2/ja not_active Expired - Fee Related
  • 2006-02-17 KR KR1020077018328A patent/KR101288663B1/ko not_active Expired - Fee Related
  • 2006-02-17 DE DE602006007546T patent/DE602006007546D1/de not_active Expired - Lifetime
  • 2006-02-17 WO PCT/EP2006/060070 patent/WO2006087375A1/en not_active Ceased
  • 2006-02-17 BR BRPI0608421-4A patent/BRPI0608421A2/pt not_active IP Right Cessation
  • 2006-02-17 PL PL06708360T patent/PL1848636T3/pl unknown
  • 2006-02-17 EP EP06708360A patent/EP1848636B1/de not_active Expired - Lifetime
  • 2006-02-17 ES ES06708360T patent/ES2328729T3/es not_active Expired - Lifetime
  • 2006-02-17 AT AT06708360T patent/ATE435157T1/de not_active IP Right Cessation
  • 2006-02-17 CN CN2006800052480A patent/CN101119894B/zh not_active Expired - Fee Related

Non-Patent Citations (1)

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