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
  • B65B11/00—Wrapping, e.g. partially or wholly enclosing, articles or quantities of material, in strips, sheets or blanks, of flexible material
  • B65B11/50—Enclosing articles, or quantities of material, by disposing contents between two sheets, e.g. pocketed sheets, and securing their opposed free margins

Definitions

• the subject invention concerns a method of wrapping articles arranged in a group in a tray in stretch film.
• at least one strand of glue is applied to each one of tuio opposite malls of the tray, whereupon gripping means extend a length of stretch film over the group of articles and the tray with the group of articles thereon is assembled with the stretch film in a manner ensuring that the film encloses the group of articles and is pressed against the parts of the tray inhere the glue is applied.
• shrink film In packaging articles in a tray of cardboard or corrugated paperboard either shrink film or stretch film is used as a rule.
• Shrink film is comparatively inexpensive but requires investments in shrink tunnels and energy for operating them.
• the method in accordance with the subject invention has for its purpose to allou. articles, arranged in a group in a tray, to be wrapped in stretch film, using a minimum amount of the film.
• the method is realized with the use of comparatively few means, uiith the result that the wrapping line requires very little space.
• the method in accordance with the invention is characterised in that two opposite marginal portions of the length of stretch film are pressed against the tray, that said gripping means thereafter release their grip on the outermost parts of said marginal portions of the film, and that said marginal film portions are thereafter pressed against said strands of glue for adhesion of the stretch film to the tray.
• the invention likewise comprises a machine for performing the method.
• the machine includes an elevating table with conveying means thereon for advancing trays with groups of articles thereon up to and away from glue spsay nozzles which are positioned on either side of the elevating table for the purpose of applying at least one strand of glue on tiuo opposite walls of the tray.
• the machine in accordance with the invention is characterised by the provision of two manipulating members which are arranged to move towards and away from one another.
• the first manipulating member is equipped with a first pair of clamping jaws and is arranged to grip the stretch film with the aid of said pair of jaws and upon its movement in the direction away from the second manipulating member to pull the stretch film over the group of articles.
• the second manipulating member is likewise equipped with a pair of clamping jaws serving to hold the stretch film on that side of the group of articles that is opposite the first pair of clamping jaws,while the film is being tensioned about said group of articles, and further with severing means to cut the required length of film, as well as with retainer means to hold the forwards end of the stretch film which is intended to be used for the following wrapping operation.
• the elevating table is arranged to raise the tray with the group of articles thereon upwards against the stretch film.
• the manipulating members while being moved simultaneously from opposite directions inwards towards the tray wrap the group of articles in the stretch film and with the aid of their clamping jaws they press the film ends against the strands of glue for adhesion of the stretch film to the tray.
• Fig. 1 is a schematic view of the machine designed to perform the method in accordance with the invention
• Fig. 2 illustrates one part of this machine in a lateral view
• Figs. 3-6 show other parts of the machine in four different positions illustrating different operational phases of the method in accordance with the invention.
• the packaging machine illustrated in Fig. 1 is provided with an elevating table 1 onto which trays 2 with a group of articles 3 thereon are advanced by a conveyer belt (not shown).
• the elevating table 1 is provided with a drive mechanism comprising a motor 4, a transmission belt 5 and drive belts 6 by means of which the trays may be transferred from the conveyor belt onto the elevating table 1 into contact with a sensing means 7 serving to stop the tray displacing movement when the table assumes its lower position shown in Fig. 1.
• the tray 2 is arranged to move past the glue applicators before it reaches the sensing means.7. Raising and lowering of the elevating table 1 to or from an upper level is effected by means of a piston-and-cylinder unit 9. Two control guides 10 are provided for guidance vertically.
• a roller conveyor (not shown), onto which the finished trays are discharged, and a supply roll
• Two manipulating members 13 and 14 are provided at the upper level of elevation to handle the stretch film 12.
• the manipulating members are arranged to be moved towards and away from one another, these movements being effected by a motor 15 which is connected to a drive shaft 17 via a transmission belt 16.
• the drive shaft 17 supports two cog belts 18 travelling about two tensioni ⁇ g rolls 19.
• the drive shaft 17 and the tensioning rolls 19 are arranged in parallel and in the same horizontal plane.
• the manipulating members 13, 14 are mounted for sliding motion along horizontal guides 20, the first one 13 of the manipulating members being connected to the upper belt parts of the cog belts 18 by means of a clamping joint 21 while the second manipulating member 14 is connected to the lower belt parts of the cog belts 18 by means of a similar clamping joint 21.
• the stretch film 12 extends from the storage roll 11 via a deflector roll 22 to a retainer element 23 provided on the right-hand manipulating member 14 as seen in Fig. 1.
• the retainer element 23 consists of a piston-and-cylinder unit 24 supporting at one end a clamping shoe 25 serving as a back-up means 26. The latter is provided with a ruler 27 projecting horizontally towards the left-hand manipulating member 13.
• the manipulating member 14 is provided with a clamping jaw 29 which is pivotally mounted on a pin 28 on the upper face of the web of stretch film 12, and with a similar clamping jaw 31 which is pivotally mounted on a pin 30 on the lower face of the film 12.
• the two clamping jaws 29, 31 are operated by piston-and-cylinder units 32 so as to perfor a movement along a curve having a comparatively large radius .
• the left-hand manipulating member 13 as seen in Fig. 1 is also provided with clamping jaws 33, 34, one of which is pivotally mounted on a pin 35 on the upper face of the stretch film 12, the other one being similarly pivotally mounted on a pin 36 on the lower face of the film web.
• the machine operates in the following manner.
• a tray 2 of corrugated paperboard supporting articles 3 arranged in a group thereon (see Fig. 1 ) is transported from the conveyor belt onto the elevating table 1 which is positioned at the lower level of elevation.
• the glue spray nozzles 8 apply glue onto each one of the long malls of the tray, for instance as is shown at 38 representing two horizontal and parallel strands of glue.
• the glue may cover the entire tray wall.
• the two manipulating members 13, 14 are moved towards one another by the motor 15, as shown in Fig. 1.
• the clamping shoe 25 of the retainer element 23 abuts against the back-up means 26, a piece of the stretch film 12 projecting between said last-mentioned shoe and back-up means while supported by the ruler 27.
• the two clamping jaws 29, 31 open sufficiently far to allow the two clamping jaws 33, 34 mounted on the manipulating member 13 to reach in between the two first-mentioned clamping jaws, gripping the ruler 27, as shown in Fig. 3 and entraining the film end away from the ruler 27.
• the retainer element 23 is lifted off the back-up means 26, whereupon the two manipulating members 13, 14 may be moved apart by the motor 15 and the cog belts 18, whereby a length L 1 of the film (see Fig. 4) is pulled out between the two manipulating members.
• the clamping jaw pair 29, 31 thereafter grips the film 12 and the two manipulating members 13, 14 are moved a further distance apart, 2 x L 2 , while tensioning the film in the lengthwise direction thereof.
• the clamping jaw 29 is provided with a severing means 39 which cuts off the film as the clamping jaws 29 and 31 are moved into contact with one another.
• the elevating table 1 is ready to be lifted upwards between the guides 20 and the cog belts 18 to the upper level of elevation.
• the two manipulating members 13, 14 move closer towards one another until the clamping jaws 29 and 33 abut against the longer walls of the tray (see Fig. 5).
• the film is still kept tensioned.
• the two clamping jaws 29 and 33 are provided with pressure pads 40 urging the stretch film 12 against the upper one of the horizontal glue strands 38 (alternatively, against the upper portion of the tray wall) on either side of the tray 2.
• the two lower clamping jaws 31 and 34 are actuated to release their grip.
• the stretch film ends thus are released, the elevating table 1 is raised, and the stretch film ends then move into position against the walls of the tray and are pressed by the pressure pads 40 against the lower glue strand 38 (alternatively, the lower portion of the tray wall) on either side of the tray 2.
• the latter is now ready to be transferred by the drive belts 6 onto the roller conveyor.
• the manipulating members 13, 14 are again moved slightly apart in order not to prevent that tray movement.
• the manipulating members 13, 14 is again lowered by the piston-and-cylinder unit 9 to the lower level of elevation while at the same time the manipulating members 13, 14 are returned to the position illustrated in Fig. 1.
• the method of wrapping articles in stretch film may be performed in a rational manner. Because the stretch film, having been extended across the articles, is applied and secured to two opposite walls of the tray 2 and not, as is the case when using prior-art technique, pulled in underneath the bottom face of the tray and secured thereto or, as is often the case, even wrapped about the entire package, each package uses considerably less of the expen sive stretch film material. In addition, the smaller amount of wrapping material also has the advantage of making it easier to open the package as the latter need no longer be lifted to loosen the film off the tray. Furthermore, because the wrapping operation is carried out on a short vertical path through the machine, the latter may be designed as a compact unit, requiring comparatively little space.
• the method in accordance with the invention is not limited to being practically realized in the machine described above but other means are possible to perform the method in accordance with the invention.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Basic Packing Technique (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20345156

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (2)

Family Cites Families (1)

• 1981
  • 1981-11-30 SE SE8107117A patent/SE8107117L/ not_active Application Discontinuation
• 1982
  • 1982-11-25 WO PCT/SE1982/000396 patent/WO1983001935A1/en active IP Right Grant
  • 1982-11-25 DE DE8282903494T patent/DE3274832D1/de not_active Expired
  • 1982-11-25 EP EP82903494A patent/EP0094955B1/en not_active Expired
  • 1982-11-25 JP JP57503565A patent/JPS58501990A/ja active Pending
  • 1982-11-26 IT IT68376/82A patent/IT1157096B/it active

Patent Citations (2)

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