Method and apparatus for packaging groups of articles which are combined to form packaging units

Abstract

A method for packaging groups of articles to form packaging units, includes sheathing a packaging unit with a film as it moves in a running direction on a transporting path by simultaneously forming a film cover and flaps projecting beyond the packaging unit along a direction perpendicular to the running direction, and positioning the flaps against the packaging unit as the packaging unit moves through a folding unit, fixing the flaps, and forming a film wrapper that is closed on all sides of the packaging unit. A preliminary-fixing step, which includes positioning the flaps in relation to one another, and initially fixing the flaps by generating heat, and exposing the flaps to the heat, follows. This is followed by a definitive-fixing step that includes exposing the packaging unit, as a whole, to generated heat.

Claims

1. A method comprising packaging groups of articles to form packaging units, wherein packaging said groups comprises receiving a packaging unit that has been wrapped by a piece of film over a top thereof while moving in a running direction on a transporting path during which said packaging unit passes over a front of said piece of film, wherein said packaging unit stands on overlapping ends of said piece of film thereby causing said piece of film to simultaneously form a film cover and flaps, wherein said flaps project beyond said packaging unit along opposite transverse directions that are perpendicular to said running direction, positioning said flaps against said packaging unit as said packaging unit moves through a folding unit, executing a preliminary-fixing step, and executing a definitive-fixing step, thereby forming a film wrapper that is closed on all sides of said packaging unit, wherein executing said preliminary-fixing step comprises passing said packaging unit between parallel heat-sources of a preliminary-fixing unit, moving said parallel heat sources along a path that extends along said running direction, and supplying an air current that applies heat to said flaps and that mechanically loads said flaps so that said flaps are reciprocally positioned and oriented relative to said packaging unit, thereby initially fixing said flaps, and wherein executing a definitive-fixing step comprises exposing said packaging unit, as a whole, to generated heat after having initially fixed said flaps.

2. The method of claim 1, wherein executing said preliminary-fixing step comprises at least partially laminating said flaps.

3. The method of claim 2, wherein at least partially laminating said flaps comprises exposing said flaps to said heat.

4. The method of claim 2, wherein at least partially laminating said flaps comprises exposing said flaps to said parallel heat sources, wherein said parallel heat sources move along said running direction and, after having moved along said path that extends in said running direction, move along said path against said running direction.

5. The method of claim 2, wherein at least partially laminating said flaps comprises using a clamping element for laminating said flaps, wherein said clamping element holds said flaps such that said flaps lie against said packaging unit in a position imposed by said folding unit as said packaging unit moves through said preliminary-fixing unit.

6. The method of claim 5, wherein using a clamping element comprises using a clamping element that is arranged on both sides and parallel to said running direction, wherein, as said packaging unit moves through said preliminary-fixing unit, said clamping element holds said flaps such that said flaps lie against said packaging unit in a position imposed by said folding unit.

7. The method of claim 1, wherein executing said preliminary-fixing step comprises executing said preliminary-fixing step after said packaging unit has passed through said folding unit and before said packaging unit has entered said definitive-fixing unit, wherein said packaging unit moves in said running direction during said preliminary-fixing step and also during said definitive-fixing step.

8. An apparatus comprising a definitive-fixing unit towards which groups of articles that have been combined to form a packaging unit move along a transporting path that leads into said definitive fixing-unit, wherein said definitive-fixing unit is configured for applying heat to said packaging unit as a whole and for definitively fixing flaps of a film cover that surrounds said packaging unit using at least said heat, wherein, when said packaging unit is received by the definitive-fixing unit after having been moved on said transporting path in a running direction thereof, said packaging unit has been covered by a film as a result of having been caused to pass over a front of said piece of film, said piece of film having been wrapped over a top of said packaging unit, wherein said packaging unit is standing on overlapping ends of said piece of film thereby causing said piece of film to simultaneously form a film cover and flaps that project beyond said packaging unit in opposite transverse directions that are perpendicular to said transporting path, wherein said apparatus comprises a fixing device and a folding unit that is separate from said fixing device, wherein said folding unit is configured for positioning said flaps against said packaging unit as said packaging unit passes through said folding unit towards said fixing device, wherein said folding unit is disposed upstream from said fixing device in said running direction, wherein said fixing device is configured to fix said flaps to each other, wherein said fixing device comprises a preliminary-fixing unit and said definitive-fixing unit, wherein said preliminary-fixing unit comprises a moving heat source that moves in a longitudinal direction parallel to said running direction and a source of an air current, wherein said source of an air current is configured for applying heat to said flaps that project in opposite transverse directions for preliminary fixing of said flaps to each other and for mechanically loading said flaps, and wherein said source of an air current is further configured for reciprocal positioning and orientation of said flaps relative to said packaging unit.

9. The apparatus of claim 8, wherein said preliminary-fixing unit is positioned downstream of said folding unit in said running direction, and wherein said definitive-fixing unit is positioned downstream of said preliminary-fixing unit in said running direction.

10. The apparatus of claim 8, wherein said definitive-fixing unit is configured to supply energy to said moving heat source.

11. The apparatus of claim 8, wherein said moving heat source of said preliminary-fixing unit extends into said definitive-fixing unit.

12. The apparatus of claim 8, wherein said preliminary-fixing unit is configured to mechanically load said flaps and wherein said preliminary-fixing unit is further configured to expose said flaps to heat concurrently with loading said flaps.

13. The apparatus of claim 8, wherein said preliminary-fixing unit comprises a clamping element, wherein said clamping element is configured for mechanically loading said flap, and wherein said clamping element is further configured for reciprocal positioning and orientation of said flap relative to said packaging unit.

14. The apparatus of claim 8, wherein said preliminary-fixing unit comprises a clamping element, wherein said apparatus further comprising a coating, wherein said coating is oriented to face said flaps, wherein said coating is disposed on said clamping element, and wherein said coating suppresses adhesion between said clamping element.

15. The apparatus of claim 8, wherein said definitive-fixing unit is disposed downstream of said preliminary-fixing unit along the transporting path in said running direction such that said packaging unit enters said definitive-fixing unit as said packaging unit leaves said preliminary-fixing unit and such that only after said packaging unit has passed through said preliminary-fixing unit does said packaging unit enter said definitive-fixing unit.

16. The apparatus of claim 8, wherein said preliminary-fixing unit comprises a rotating tape that, after having been heated, reradiates heat for laminating said flaps.

17. The apparatus of claim 16, wherein said rotating tape is configured to move at the same speed as said packaging unit along said running direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other features of the invention will be apparent from the following detailed description, and the accompanying figures, in which:

(2) FIG. 1 shows an apparatus in schematic form with a folding unit and a preliminary-fixing unit,

(3) FIG. 2 shows the apparatus of FIG. 1 with a definitive-fixing unit,

(4) FIG. 3 shows an alternative embodiment of the preliminary-fixing unit, and

(5) FIG. 4A-4D show additional embodiments of the preliminary-fixing unit in schematic form.

DETAILED DESCRIPTION

(6) FIGS. 1 and 2 shown an apparatus for packaging articles 1 that have been combined into groups to form packaging units 2. In the particular embodiment shown, the articles 1 are cans that have been arranged in a matrix. However, other articles can also be combined and processed by the illustrated apparatus.

(7) The actual grouping of the articles 1 to form the packaging unit 2 is carried out by appropriate sorting and orienting devices upstream of the apparatus. These devices need not be illustrated in detail.

(8) Also implicitly present, but not illustrated in the figures, is a feed drum for feeding a film 3 placed around the packaging unit 2 as illustrated in FIG. 1. In the illustrated embodiment, the film 3 is a shrinkable plastic film, such as a film made of PE (polyethylene), PET (polyethylene terephthalate), PP (polypropylene).

(9) The sheathing of the particular packaging unit 2 occurs when, as it proceeds in a running direction L during the transport of the group of articles 1 along a transporting path T, it passes over a front end of a film wrap that has been cut and fed through a slot in the transporting path T.

(10) As the packaging unit 2 proceeds further along the transporting path T, a film-carrier bar under the film wrap travels from below and describes a circular path, or a generally circular path, under the packaging unit 2 in the running direction L. The film-carrier bar then enters another slot, taking the rear end of the film wrap with it as it does so. When transporting the thus wrapped packaging unit 2 in the running direction L, the latter travels over the slot and thereby pulls the front end of the film wrap under it. In this way, the packaging unit 2 stands on the overlapping ends of the film wrap. As it does so, it defines a film cover 4. Further details of the described sheathing method are described in DE 42 07 725 A1.

(11) The foregoing procedure defines a plurality of flaps 5-8 that project beyond end faces of the packaging unit 2 in a transverse direction that is perpendicular to the running direction L. First and second flaps 5-6 lie opposite each other and extend in planes perpendicular to that defined by the transporting path T. The first and second flaps 5-6 are arranged on the packaging unit 2 by a largely vertical folding process as the packaging unit 2 enters a folding unit 9. Third and fourth flaps 7, 8 also lie opposite each other and extend in planes parallel to that defined by the transporting path T. The third and fourth flaps 7-8 are likewise positioned against the packaging unit 2 by a largely horizontal folding operation. The particular folding operations are indicated in FIG. 1 by corresponding fold lines.

(12) In the illustrated embodiment, the folding unit 9 includes first and second stationary folding-elements 10, 11. The first stationary folding-element 10 is a clamping rail. The second stationary folding-element 11 is a diagonal guide 11.

(13) The folding unit 9 also includes first and second moving folding-elements 12-13. The moving folding-elements 12-13 move synchronously with the packaging unit 2 as it travels along the transporting path T in the running direction L. The first moving folding element 12 is a rotating folding disc 12. The second moving folding element 13 is a folding carrier 13 that moves with the packaging unit 2. As the packaging unit 2 passes through it, the folding unit 9 positions the flaps 5-8 against the packaging unit 2, as is illustrated in FIGS. 4A to 4D. Because folding units are known, there is no need for further details of the folding operation or the construction of the folding unit 9.

(14) The folding unit 9, which is arranged after the sheathing unit, folds the flaps 5-8 against the packaging unit 2 as the packaging unit 2 moves through.

(15) Downstream of the folding unit 9 is a fixing device 14-16 for reciprocal fixing of the flaps 5-8 relative to each other. In the illustrated embodiment, the fixing device 14-16 includes two fixing units: preliminary-fixing unit 14-15 and a definitive-fixing unit 16.

(16) Although other kinds of definitive-fixing unit 16 can be used, in the illustrated embodiment, the definitive-fixing unit 16 is a shrink tunnel that is fitted with its own heat source inside it. Examples of a heat source include a hot-air blower with nozzles, and an infrared heating element.

(17) The preliminary-fixing unit 14-15 ensures that the film wrapper formed by the film 3 is closed on all sides, and that it remains closed on all sides during the shrink process in the definitive-fixing unit 16. The preliminary-fixing unit 14-15 guarantees that the flaps 5-8 are simultaneously positioned in relation to one another and initially fixed, in a preliminary manner, by heat. The entire packaging unit 2 then undergoes a definitive fixing, again by heat, in the definitive-fixing unit 16.

(18) The preliminary-fixing unit 14-15 follows the folding unit 9. In the illustrated embodiment, the preliminary-fixing unit 14-15 immediately follows the folding unit 9 so that there are no further elements or units placed between them. The definitive-fixing unit 16 then follows the preliminary-fixing unit 14-15. Preferably, the definitive-fixing unit 16 is directly adjacent to the preliminary-fixing unit 14-15, with no other units or elements being placed between them.

(19) In some embodiments, the preliminary-fixing unit 14-15 includes a stationary heat source 15 extending in a longitudinal direction, as shown in FIGS. 4A-4D. In other embodiments, the heat source 15 moves with the packaging unit 2 as the packaging unit 2 moves along the transporting path T in the running direction L, as shown in FIG. 3.

(20) The preliminary-fixing unit 14-15 also has a clamping element 14. In some embodiments, the heat source 15 and the clamping element 14 are separate from each other. However, in other embodiments, the clamping element 14 and the heat source 15 form a module as illustrated in FIG. 4D.

(21) The clamping element 14 holds the flaps so that they lie against the packaging unit 2 in the position imposed by folding unit 9 as the packaging unit 2 moves moving through the preliminary-fixing unit 14-15. In this way, the preliminary-fixing unit 14-15 mechanically loads the flaps 5-8 and, at the same time, exposes them to heat.

(22) In FIG. 3 and FIGS. 4A-4C, the heat source 15 is a stand-alone component of the preliminary-fixing unit 14-15 that is independent of the heat source in the definitive-fixing unit 16. However, in the embodiment shown in FIG. 4D, the heat source 15 is supplied with energy in whole or in part from the definitive-fixing unit 16 or the shrink tunnel. In this embodiment, the heat source 15 of the preliminary-fixing unit 14-15 reaches or can reach through into the definitive-fixing unit 16.

(23) In FIG. 4D, the heat source 15 comprises a guide or two fixed guides that extend into the shrink tunnel and at the same time function as the clamping element 14. In this way, a heat source located in the shrink tunnel supplies energy to the heat source 15 via the guides.

(24) Within the shrink tunnel, nozzles can be made as components of the previously mentioned hot-air blower to direct hot air against the packaging unit 2. At the same time, these nozzles also direct hot air at the guides 14 and at the heat source 15.

(25) The preliminary-fixing unit 14-15 mechanically loads the flaps 5-8 using the clamping element 14. However, there are other ways to mechanically load the flaps 5-8. For example, it is also possible to position and orient the flaps 5-8 relative to each other by an air current.

(26) FIG. 4B shows a clamping element 14 is designed as a rotating chain. The chain runs around the stationary heat source 15. In this way, the heat source 15 is able to expose the flaps 5-8 to appropriate hot air currents in the way and manner described or can ensure that the flaps 5-8 remain positioned against the packaging unit 2 as the packaging unit 2 moves through the preliminary-fixing unit 14-15, as shown by corresponding arrows in FIG. 4B. In addition, the clamping element 14, or the chain, ensures the desired positioning.

(27) In another embodiment, shown in FIG. 4A, the clamping element 14 is a rotating tape. The heat source 15 exposes the rotating tape 14 to heat, thus heating the rotating tape and enabling it to reradiate heat for laminating the flaps 5-8 onto them. At the same time, the clamping element 14 ensures that the flaps 5-8 remain positioned against the packaging unit 2 as it moves through the preliminary-fixing unit 14-15. In some embodiments, the rotating of the clamping element 14 is a tape made of polytetrafluorethylene. Like the chain shown in FIG. 4B, the tape moves along the transporting path T at the same speed as the packaging unit 2 in the running direction L.

(28) In FIG. 4C, stationary heating nozzles form the heat source 15. In addition, a guide 14 underneath the heating nozzles or the heat source 15 holds the flaps 5-8 positions them against the packaging unit 2 as it moves through the preliminary-fixing unit 14-15. The heat source 15 ensures that the flaps 5-8 are exposed to heat and immediately laminated.

(29) In some embodiments, energy-rich radiators, such as infrared heaters replace the heating nozzles. These infrared heaters enable the use of appropriate shields form very a well-defined zone of action. This is difficult to do heating gas. The use of radiators, such as infrared radiators, is also advantageous for other embodiments described herein.

(30) Both the clamping element 14 and the heat source 15 receive a coating on at least a side that faces the flaps 5-8. This coating can be a polytetrafluorethylene coating. Such a coating suppresses adhesion from the lamination occurring as the flaps 5-8 pass through. This avoids impeding the transport of the packaging unit 2 in the running direction L along the transporting path T.

(31) Elements from the various embodiments described herein can be combined with other elements to form additional embodiments. For example, heating can be provided additionally by an infrared heater or hot air from a rotating heating tape if part of the heating energy is drawn from the connected shrink tunnel. The use of radiators, in particular infrared heaters, is advantageous for all the embodiments described herein because such heaters require only a very small space and need no drive unit, as is the case with the use of hot gas as a heat source. In addition, the use of infrared radiation avoids unwanted gas movements.