Patent Publication Number: US-6341474-B1

Title: Cigarette pack and process and apparatus for producing the same

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a cigarette pack of the soft-carton type, having an (outer) blank which is made of paper and encloses the pack contents, forming in the process a base wall, comprising folding tabs, and a side wall, comprising mutually overlapping side tabs, it being the case that the folding tabs of the base wall and the side tabs are connected to one another by adhesive bonding. The invention also relates to a process and an apparatus for producing packs of this type. 
     Soft-carton packs represent one of the cigarette packs which is used most widely throughout the world. These soft-carton packs usually comprise an inner blank which is made of tin foil or paper and fully envelops the pack contents—a cigarette group. A cigarette block formed in this way is positioned in a soft carton, that is to say a carton-like pack which is open at the top and is made of paper or similar packaging material. The soft carton has folding tabs which are adhesively bonded to one another in the region of the base wall and side tabs which are connected to one another, likewise by adhesive bonding, in the region of an upright, narrow side wall. Furthermore, usually a revenue stamp is provided as closure means. This revenue stamp extends in a U-shaped manner, transversely and centrally, over an end wall of the cigarette block. Legs are connected to the front wall and rear wall of the soft carton by adhesive bonding, 
     Packaging machines for producing (cigarette) packs of this type are designed for increasingly high outputs. The latter result in problems, in particular, where the gluing of the packs or of the blanks is concerned. 
     SUMMARY OF THE INVENTION 
     The object of the invention is for the packs mentioned in the introduction to be developed further as far as the gluing or adhesive bonding is concerned such that areas of glue or applications of glue can be applied to folding tabs, side tabs, etc. at a high operating or conveying speed and the relevant regions of the blank can be glued to one another. 
     In order to achieve this object, the pack according to the invention is characterized in that the side tabs are connected to one another by a plurality of rectangular or square applications of glue comprising hot-melt glue, said applications being spaced apart from one another in the longitudinal direction of the side tabs, and the folding tabs of the base wall are connected to one another by a rectangular application of glue comprising hot-melt glue, said application running in the longitudinal direction of the base wall. 
     The use of hot-melt glue has advantages from a process-engineering standpoint. According to the invention, the applications of glue are already applied in the correct position to a continuous material web for the purpose of forming blanks for the pack, to be precise the applications are applied by stationary slotted nozzles, the material web being moved past the latter during appropriately controlled opening cycles of nozzle slots. Once the applications of glue have set, the material web can be processed without difficulty, that is to say blanks can be severed and folded. 
     A further special feature of the pack according to the invention consists in that the revenue stamp is connected to the pack exclusively by applications of glue comprising hot-melt glue in the region of front wall and rear wall of the soft carton. Accordingly, all applications of glue for the pack are provided on the material web for the purpose of producing soft-carton blanks. 
     The applications of glue are reactivated by heat in the region of the packaging machine. According to the invention, elements of the packaging machine are heated, with the result that heat is transferred onto those regions of the blank which have applications of glue. The elements heated are preferably those which are directly involved with the processing of those parts of the blank which are provided with applications of glue, that is to say they have a double function. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further details of the pack according to the invention, of the production process and of the apparatus are explained in more detail hereinbelow with reference to details of the packaging machine which are illustrated in the drawings, in which: 
     FIG. 1 shows a spread-out blank for a soft carton, 
     FIG. 2 shows a spread-out blank for another type of soft carton, 
     FIG. 3 shows a schematic plan view of an installation for producing (cigarette) packs of the soft-carton type, 
     FIG. 4 shows, on an enlarged scale, a detail of the installation according to FIG. 3 corresponding to arrow IV in FIG. 3, 
     FIG. 5 shows a schematic side view of a sub-region of a packaging machine, 
     FIG. 6 shows, on an enlarged scale, a schematic side view of elements of a folding turret of the packaging machine, 
     FIG. 7 shows a further detail of the folding turret in an axis-parallel section, 
     FIG. 8 shows a plan view of a folding or processing element of the folding turret, 
     FIG. 9 shows, partly in section, an axial view of a sub-region of a drying turret, 
     FIG. 10 shows, on an enlarged scale, a detail of the drying turret according to FIG. 9, 
     FIG. 11 shows an element of the drying turret, namely a drying tube, in longitudinal section, and 
     FIG. 12 shows a plan view of the drying tube according to FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The exemplary embodiments which are illustrated in the drawings are involved with the configuration and production of (cigarette) packs  10  of the soft-carton type. These comprise an inner blank  11  which is made of tin foil or paper and fully envelops the pack contents—a cigarette group. This produces a cigarette block, which is then enclosed by an outer blank  12  made of paper or similar material. The outer blank  12  is folded in the standard procedure so as to produce a soft carton (FIG.  7 ). The inner blank  11  or the cigarette block projects out of said soft carton to a slight extent at the top. The pack  10  formed in this way may be enclosed by a film blank. 
     The outer blank  12  comprises, according to FIG. 1, a front wall  13 , rear wall  14 , side walls  15  and  16  and a base wall  17 . The side wall  16  comprises two side tabs  18  and  19  which are each arranged on mutually opposite border regions of the outer blank  12  and wholly or partially overlap one another (e.g. FIG.  10 ). 
     The base wall  17  likewise comprises folding tabs, namely trapezoidal longitudinal tabs  20  and  21  and further rectangular or square and triangular base tabs. 
     In the same way as the side tabs  18  and  19 , the longitudinal tabs  20 ,  21  are connected to one another by adhesive bonding. 
     The blank or outer blank  12  is provided with applications of glue comprising a glue which sets and can be reactivated by heat—so-called hot-melt glue—before the folding process, in the present case in the region of a continuous material web  22  made of paper or the like. The glue is applied to the material web  22  as the material web  22  is transported, in accordance with the configuration of the outer blank  12  (FIG.  1 ). For this purpose, the material web  22  is moved past a glue assembly  23 . 
     The glue assembly  23  is equipped with at least one slotted nozzle  24 . The latter has a plurality of nozzle slots arranged transversely with respect to the material web  22 . These can be controlled, as far as the open and closed positions are concerned, such that rectangular or square applications of glue are transferred onto the material web  22  moving past them. The material web is pressed onto the slotted nozzle  24  by supporting rollers  25 ,  26 . Otherwise, the glue assembly  23  is expediently designed in the manner illustrated and described in DE 195 35 649.7. 
     Taking the operation of the glue assembly  23  into consideration, an (outer) blank  12  according to FIG. 1 has applications of glue arranged in a particular manner. The (inner) side tab  19  is provided with a row of approximately square side applications of glue  27  which are arranged one beside the other and extend over the entire length of the side tab  19 , to be precise on the outside of the outer blank  12 . The side applications of glue  27  serve for the purpose of connecting the (inner) side tab  19  to the (outer) side tab  18 . 
     An elongate, rectangular base application of glue  28  is arranged in the region of the inner longitudinal tab  21  for the purpose of connecting the folding tabs of the base wall  17 . Said base application of glue connects the longitudinal tab  21  to the outer longitudinal tab  20  and thus fixes the base wall  17  as a whole. 
     A further special feature is the arrangement of in each case elongate, rectangular revenue-stamp applications of glue  29 ,  30 . These are in the region of the front wall  13 , on the one hand, and of the rear wall  14 , on the other hand, to be precise central in each case and adjacent to a free, top border of the outer blank  12  These revenue-stamp applications of glue  29 ,  30  serve for the purpose of fixing downwardly directed legs of a revenue stamp  31  folded in a U-shaped manner. The revenue-stamp applications of glue  29 ,  30  are arranged at equal spacings from the free border of the outer blank  12  and are applied by a slot of the slotted nozzle  24 , said slot also applying the side application of glue  27  on the border of the blank. The relevant nozzle slot is opened three times during the gluing of a blank, to be precise during transportation of the outer blank  12 , as a region of the material web  22 , in the direction of the arrow  32 . 
     The precise actuation of the slotted nozzle  24  is ensured by control markings  33  which are provided at correct spacings on the material web  22 . 
     FIG. 2 shows an outer blank  12  which is intended for a modified pack of the soft-carton type. Details concerning the design and production of this particular soft-carton pack can be gathered from EP 0 649 797. The blank according to FIG. 2, which is likewise severed from a continuous web, forms two folding strips  34 ,  35  in the region of the base wall  17 , which is to be folded. The folding strip  35  is folded against the folding strip  34  along a folding line  36 , with the result that the outer blank  12  is of double-layered design in the region of the base wall  17 . The folding tabs of the base wall  17  are then formed in the customary manner, namely with (double-layered) longitudinal tabs  20 ,  21 . The inner longitudinal tab  21  is provided with the abovedescribed base application of glue  28  on the outside Accordingly, said application of glue is provided in the region of the folding strip  34 , analogously to the blank according to FIG.  1 . 
     In the region of an end wall  77  too, this soft pack is designed corresponding to EP 0 649 797, with a folding strip for the purpose of forming two folding legs  37 ,  38  of a Z-fold on the top border of the carton. The two folding legs  37 ,  38  are connected to one another by adhesive bonding. An approximately square Z-region application of glue  39  is provided in the region of the folding leg  38 . This application of glue connects the two folding legs  37 ,  38  when the latter are folded in the form of a Z. The Z-region application of glue  39  is formed in the region of an extension of the side tab  18 . 
     As far as the provision of side applications of glue  27  is concerned, the side tab  19  is designed in the same manner as the blank according to FIG. 1, that is to say with seven spaced-apart rectangular or square side applications of glue  27 . Revenue-stamp applications of glue  29 ,  30  are positioned in the region of the front wall  13  and rear wall  14 , to be precise adjacent to a folding edge  40 , which in the case of this type of pack forms a top border of the (apparent) carton. The Z-region application of glue  39  is expediently activated together with the side applications of glue  27 , that is to say on the folding mandrel  55  by the folder  65 . It is also possible, however, for the Z-region application of glue  39  to have been activated already in the region of the correspondingly folded material web for producing blanks with a Z-fold. 
     A production installation according to FIG. 3 serves for producing packs  10  of the type described. This installation comprises a packaging machine  41  and a separate material unit  42 . The latter is positioned on the rear side of the packaging machine  41  and is expediently designed in accordance with DE 198 04 614.6. The material unit  42  contains reel magazines for the web-like packaging material which is to be processed. These are, on the one hard, tin-foil reels  43  and, on the other hand, paper reels  44 , and revenue-stamp reels  45  are also provided. 
     The reels  43 ,  44 ,  45  are mounted rotatably in each case on an operating stub  46 ,  47 ,  48 , with the result that the material webs can be drawn off. These material webs are fed to the packaging machine  41 . Of particular interest in the present case is the material web  22  for producing the (outer) blanks  12  made of paper. 
     The material web  22 , which is drawn off from, the respective paper reel  44  on the operating stub  47 , runs through a splicing assembly  49 , which has the task of connecting a finishing material web  22  to a new material web of a reel which is to be joined up. Thereafter, the material web  22  runs through a web store  50  for the purpose of compensating for differences in movement. This is followed by the abovedescribed glue assembly  23 , which in this case is arranged in the region of the material unit  42 . 
     The material web  22 , provided with glue or applications of glue in the manner described, is fed to a folding assembly, that is to say to a folding turret  51  which rotates continuously in the upright plane. This folding turret is assigned circumferentially spaced-apart assemblies for the task of feeding the material web  22  and for the task of severing the blanks  11  and  12 . Otherwise, the folding turret  51  may be designed in accordance with US 4 852 335. 
     A material web made of tin foil is fed in the region of a tin-foil station  52  for the purpose of forming inner blanks  11 . Arranged in a position offset with respect to this in the circumferential direction is the paper station  53 . The latter has a severing assembly  54  for the purpose of severing the (outer) blanks  12  from the material web  22 . 
     For the purpose of producing packs  10  of the soft-carton type, the folding turret  51  is provided with a plurality of circumferentially spaced-apart material-receiving means, namely so-called folding mandrels  55 . These are elongate hollow bodies which are open at both ends and whose dimensions correspond to the inner dimensions of the pack  10 . The blanks, namely inner blank  11  and outer blank  12 , are folded on the outside of the thin-walled hollow mandrels  55 . The pack contents, namely a cigarette group, are introduced into the folding mandrel  55  in the longitudinal direction by a push rod  56 . For the purpose of forming the filled pack  10 , the cigarettes are pushed out by the push rod  56 , the partially folded blanks  11 ,  12  being carried along in the process. 
     As can be seen from FIG. 7, in the region of the paper station  53 , the outer blanks  12  are placed in the correct position on the folding mandrel  55  or on the inner blank  11 . The base wall  17  is folded against an already folded base wall of the inner blank  11 . 
     In the initial position, a material strip for the purpose of forming the folding tabs of the base wall  17  projects beyond the free side of the folding mandrels  55 , connected to a turret plate  57 . First of all an inner tab  58  is folded, by a stationary folding finger (not shown). Thereafter, an opposite inner tab  59 , which is at the rear in the transporting direction, is folded, from parts of the side tabs  18 ,  9 , by a movable folding finger  60 . Thereafter, the radially outer and inner longitudinal tabs  20 ,  21  are folded by fixed folding deflectors  61 ,  62 , as a result of the movement relative to the latter. 
     Before the inner tab  59  is folded over, the side tabs  18 ,  19  are folded. The radially outer side tab  19 , which is located on the inside of the finished pack  10 , is first of all folded against the rear side surface of the pack  10 , as seen in the movement direction, by a folding element, to be precise by a folding wheel  63  with projecting folding webs  64 . Thereafter, or in a simultaneous movement, the radially inner, cuter side tabs  18  are folded by a separate, movable folding element. This is an angled folder  65  which uses a folding leg  66 , projecting at right angles, to grip the side tab  18  and fold it over against the approximately radially directed side surface of the pack  10  or of the folding mandrel  55 . For this purpose, the folder  65 , which is assigned to each folding mandrel  55 , is mounted pivotably. 
     Before, during or after folding of the folding tabs coated with applications of glue, the applications of glue have to be activated by the supply of heat. 
     The first to be activated are the side applications of glue  27  for the purpose of connecting the side tabs  18  and  19 . The heat required for this purpose is transferred by folding elements, namely by the folder  65 . The latter is heated throughout or in the region of the folding legs  66 . For this purpose, an (electric) heating cartridge  67  is provided on each folder  65 . This heating cartridge is activated during the folding operation (FIG.  6 ), in particular during abutment of the folding legs  66  against the side tab  18 . In this case, the heat is transferred over a sufficient period of time since the folder  65 , in the folding position, runs along with the folding mandrel  55 . 
     The applications of glue arranged in the region of the base wall  17 , namely the base application of glue  28 , are/is activated following the side applications of glue  27 . Following the abovedescribed folding steps for the base wall  17 , a pressure-exerting element for the folding tabs of the base wall  17  is arranged in a stationary manner. This element is a pressure-exerting roller  68 . The blanks  11 ,  12  still positioned on the folding mandrel  55  are moved past said pressure-exerting roller such that the folding of the base wall  17  is stabilized by transferred pressure. On the inside, namely in the folding mandrel  55 , the push rod  56  acts as a counterpressure element. The pressure-exerting roller  68  is heated (indirectly), to be precise by a heating cartridge  69  which is mounted within a mount  70  for the pressure-exerting roller  68 . 
     The (heated) pressure-exerting roller  68  is adjoined, in the conveying direction, by a heated pressure-exerting part  71 . The latter is configured as an arcuate shaped body in accordance with the movement path of the pack  10  or of the base wall  17 . The latter slides on the pressure-exerting part  71  during a section of the circular movement. In the present case, the pressure-exerting part  71  is a part, or continuation, of the mount  70  for the pressure-exerting roller  68 . Heating cartridges  72  are positioned at a suitable location in the pressure-exerting part  71  for the purpose of heating the same. 
     The pressure-exerting part  71  is adjoined in the conveying direction by a pressure-exerting plate  73 , which is a further pressure-exerting element for the base wall  17 . The pressure-exerting plate  73  is not heated, and may be cooled in order to stabilize the connection of the folding tabs of the base wall  17 . This base wall slides along the fixed pressure-exerting plate  73  during the conveying movement. 
     The revenue stamp  31  is applied and adhesively bonded in the region of a drying turret  74 . Unless described or illustrated to the contrary, this drying turret may be designed in accordance with U.S. Pat. No. 5,544,467. The packs  10  completed and filled in the region of the folding turret  51  are fed to the drying turret  74  via a transfer turret  75 . The drying turret comprises a plurality of hollow bodies, namely drying tubes  76 , which are arranged along the circumference and through which the packs  10  are transported in an axis-parallel direction, to be precise by virtue of a new pack  10  being pushed in at one end of a drying tube  76  and a finished pack  10  emerging on the opposite side of the drying tube  76 . In the case of the present example, each drying tube  76  is designed such that three packs  10  are accommodated one after the other in the drying tube, it being the case that the front end walls  77 , as seen in the push-through direction, are supported in each case on the base wall  17  of a preceding pack  10 . 
     The drying tube  76  is designed with an approximately C-shaped cross section, that is to say a radially inner tube base  78 , approximately radially directed side guides  79 ,  80  and an outer wall  81 . The latter extends only over a sub-region of the outwardly directed large-surface-area wall of the pack, that is to say of the front wall  13 . This results in an open slot  82  running in the longitudinal direction of the drying tube  76 . 
     In the region of the drying tube  76 , the revenue stamps  31  are provided on the front end wall  77 , as seen in the conveying direction. By virtue of the relevant pack  10  being pushed into the associated drying tube  76 , the revenue stamp  31  is folded over in a U-shaped manner, with the result that legs  83 ,  84  butt against front wall  13  and rear wall  14 , to be precise in the region of the revenue-stamp applications of glue  29 ,  30 . 
     The revenue-stamp applications of glue  29 ,  30  for the purpose of fixing the revenue stamp  31  are activated once the revenue stamp  31  has been folded, namely in the region of the drying tube  76 . For this purpose, heating elements, namely heating cartridges  85 ,  86 , are arranged at a certain position of the drying tube  76 , in the tube base  78  and in the outer wall  81  opposite this. These heating cartridges are each positioned at the location at which the revenue-stamp applications of glue  29 ,  30  are located once a (new) pack  10  has been pushed into the drying tube  76  (FIG.  11 ). Virtually an entire revolution of the drying turret  74  is available for the activation of the revenue-stamp applications of glue  29 ,  30 . Thereafter, that is to say following further movement of pack  10 , the glue connection can set, while being fixed by the drying tube  76 . 
     The packs emerging from the drying tube  76  are processed further in a known manner, for example in accordance with EP 0 770 551. 
     The drying tubes  76  are designed in a particular way. In the region of the transition from the side guide  80  into the outer wall  81 , there is formed a collecting channel  87  which extends in the longitudinal direction of the drying tube  76 . This collecting channel serves for receiving any residues of glue which may emerge from the region between the side tabs  18  and  19 . 
     Alternatively, the apparatus may also be operated such that the activation of all the applications of glue does not take place until the drying turret or the drying tubes  76  has/have been reached. In this case, for example pusher elements for the purpose of pushing the packs  10  into the drying tubes  76  are heated for the purpose of activating the base applications of glue  28 . Furthermore, it is possible for the side guide  80  to be heated for the purpose of activating the side applications of glue  27 . 
     The applications of glue may also be applied to the material web in other ways, for example by offset printing or intaglio printing. It is also possible for applications of glue which can be activated to be provided on the material web during the production, that is to say printing, of the latter, this resulting in finished material webs, as far as the applications of glue are concerned, being supplied. 
     LIST OF DESIGNATIONS 
       10  Pack 
       11  Inner blank 
       12  Outer blank 
       13  Front wall 
       14  Rear wall 
       15  Side wall 
       16  Side wall 
       17  Base wall 
       18  Side tab 
       19  Side tab 
       20  Longitudinal tab 
       21  Longitudinal tab 
       22  Material web 
       23  Glue assembly 
       24  Slotted nozzle 
       25  Supporting roller 
       26  Supporting roller 
       27  Side application of glue 
       28  Base application of glue 
       29  Revenue-stamp application of glue 
       30  Revenue-stamp application of glue 
       31  Revenue stamp 
       32  Arrow 
       33  Control marking 
       34  Folding strip 
       35  Folding strip 
       36  Folding line 
       37  Folding leg 
       38  Folding leg 
       39  Z-region application of glue 
       40  Folding edge 
       41  Packaging machine 
       42  Material unit 
       43  Tin-foil reel 
       44  Paper reel 
       45  Revenue-stamp reel 
       46  Operating stub 
       47  Operating stub 
       48  Operating stub 
       49  Splicing assembly 
       50  Web store 
       51  Folding turret 
       52  Tin-foil station 
       53  Paper station 
       54  severing assembly 
       55  Folding mandrel 
       56  Push rod 
       57  Turret plate 
       58  Inner tab 
       59  Inner tab 
       60  Folding finger 
       61  Folding deflector 
       62  Folding deflector 
       63  Folding wheel 
       64  Folding web 
       65  Folder 
       66  Folding leg 
       67  Heating cartridge 
       68  Pressure-exerting roller 
       69  Heating cartridge 
       70  Mount 
       71  Pressure-exerting part 
       72  Heating cartridge 
       73  Pressure-exerting plate 
       74  Drying turret 
       75  Transfer turret 
       76  Drying tube 
       77  End wall 
       78  Tube base 
       79  Side guide 
       80  Side guide 
       81  Outer wall 
       82  Slot 
       83  Leg 
       84  Leg 
       85  Heating cartridge 
       86  Heating cartridge 
       87  Collecting channel