Abstract
Packaging method and device in which, with the aid of a stretch hood system 1, a tubular film portion 3 is drawn over an article 2 that is to be packaged. The tubular film portion 3 is firstly reefed with the aid of a reefing device 8 onto at least two reefing fingers 7 of a drawing-over device 6. Then, by moving the drawing-over device 6 along the article 2 that is to be packaged, the tubular film portion 3 is unreefed from the reefing fingers 7 of the drawing-over device 6 and drawn at least in sections over the article 2. During the reefing, the tubular film portion 3 is at least intermittently inflated.
Claims
1-20. (canceled)
21: A stretch-hood device for wrapping an article with a tubular film portion, the stretch-hood device comprising: a tube-opening device configured to open the tubular film portion; a drawing-over device including two reefing fingers; a reefing device configured to reef the tubular film portion onto the reefing fingers and unreef the tubular film portion from the reefing fingers; and an inflating device configured to direct gas into an interior of the tubular film portion during at least one of the opening, the reefing, and the unreefing.
22: The stretch-hood device of claim 21, wherein the tube-opening device includes the inflating device.
23: The stretch-hood device of claim 21, wherein one of the reefing fingers includes the inflating device.
24: The stretch-hood device of claim 23, wherein the inflating device comprises an outlet opening through which the gas is expelled from the inflating device.
25: The stretch-hood device of claim 24, wherein the inflating device further comprises a closure element configured to selectively close the outlet opening.
26: The stretch-hood device of claim 25, wherein the outlet opening is arranged on a side of the reefing finger opposite a reefing-on surface of the reefing finger.
27: The stretch-hood device of claim 21, wherein the tube-opening device comprises multiple suction boxes configured to engage and releasably retain part of the tubular film portion.
28: The stretch-hood device of claim 27, wherein the suction boxes are movable relative to one another to open the tubular film portion.
29: The stretch-hood device of claim 21, wherein the inflating device comprises one of a fan and a compressed air source.
30: A method for wrapping an article with a tubular film portion, the method comprising: opening, via a tube-opening device, the tubular film portion; reefing, via a reefing device, the tubular film portion onto two reefing fingers of a drawing-over device; while moving the drawing-over device relative to the article, unreefing, via the reefing device, the tubular film portion from the reefing fingers onto the article; and directing gas into an interior of the tubular film portion via an inflating device during at least one of the opening, the reefing, and the unreefing.
31: The method of claim 30, wherein directing the gas into the interior of the tubular film portion causes the tubular film portion to inflate such that the tubular film portion is taut at its open lower end.
32: The method of claim 30, further comprising welding, via a welding device, an upper end of the tubular film portion to close the upper end of the tubular film portion.
33: The method of claim 32, wherein directing the gas into the interior of the tubular film portion occurs during or after the welding.
34: The method of claim 30, further comprising inserting the reefing fingers into an open lower end of the tubular film portion while directing the gas into the interior of the tubular film portion and while the tube-opening device holds the tubular film portion.
35: The method of claim 30, further comprising changing a flow rate of the gas via an adjusting device.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The subject matter of the invention is explained in more detail below on the basis of different illustrative embodiments and with reference to the schematic drawings, in which:
[0040] FIG. 1 shows a perspective view of a stretch hood system of the type in question according to the prior art;
[0041] FIGS. 2a to 2e show successive steps of a method section of a packaging method of the type in question using the stretch hood system shown in FIG. 1; (a) inserting the reefing fingers into the tubular film portion; (b) release of the tubular film portion by the tubular-film-opening device; (c) moving the suction boxes away from the tubular film portion; (d) moving the reefing fingers to the tubular film portion; and (e) moving the reefing drives to the reefing fingers;
[0042] FIG. 3 shows a perspective view of a first illustrative embodiment of a stretch hood system according to the present disclosure;
[0043] FIGS. 4a to 4e show successive steps, of the method section shown in FIGS. 2a to 2e, of a packaging method according to the present disclosure in a first illustrative embodiment using the stretch hood system shown in FIG. 3: (a) inserting the reefing fingers into the tubular film portion; (b) release of the tubular film portion by the tubular-film-opening device; (c) moving the suction boxes away from the tubular film portion; (d) moving the reefing fingers to the tubular film portion; and (e) moving the reefing drives to the reefing fingers;
[0044] FIG. 5 shows a perspective view of a detail of the stretch hood system shown in FIG. 3, during the method step in FIG. 4a;
[0045] FIG. 6 shows a perspective view of a detail of the stretch hood system shown in FIG. 3, during the method step in FIG. 4e;
[0046] FIG. 7 shows a perspective view of a detail of the stretch hood system shown in FIG. 3, during the reefing;
[0047] FIG. 8 shows a perspective view of a detail of the stretch hood system shown in FIG. 3, during the unreefing;
[0048] FIG. 9 shows a perspective view of a reefing finger of the stretch hood system shown in FIG. 3;
[0049] FIGS. 10a to 10d show successive steps, of the method section shown in FIGS. 4a to 4e, of a packaging method according to the present disclosure in a second illustrative embodiment using the stretch hood system shown in FIG. 3: (a) inserting the reefing fingers into the tubular film portion; (b) release of the tubular film portion by the tubular-film-opening device; (c) moving the reefing drives to the reefing fingers; and (d) moving the suction boxes away from the tubular film portion;
[0050] FIG. 11 shows a perspective view of a tubular film portion in the opening system of a stretch hood system according to the prior art; and
[0051] FIG. 12 shows a perspective view of a tubular film portion in the opening system of a stretch hood system according to one embodiment of the present disclosure.
[0052] FIG. 1 shows a perspective overall view of a stretch hood system 1 of the type in question known from the prior art, with which a tubular film portion 3 can be drawn over an article 2. In order to better illustrate the main sequences, not all components are explicitly shown.
DETAILED DESCRIPTION OF THE DRAWINGS
[0053] In the present illustrated embodiment, the stretch hood system 1 has a reserve of tubular film in the form of a reel of the tubular film. The tubular film portion 3 is therefore only generated in the stretch hood system 1. However, it is conceivable, and also within the scope of the present disclosure, that tubular film portions are used that have already been cut to length in advance.
[0054] To make available the required tubular film portion 3, the stretch hood system 1 has a film supply device 5. The latter is arranged in the upper area of a machine frame 4 of the stretch hood system 1. A drawing-over device 6 and a reefing device 8 are arranged inside the machine frame 4.
[0055] As can be seen in FIGS. 1 and 2a, the stretch hood system 1 has a tube-opening device 15 with four suction boxes 18 at which holding devices 16 are mounted. Moreover, the reefing device 8 has four reefing drives 9a to reef the tubular film portion 3 onto four reefing fingers 7 of the drawing-over device 6. In addition to the cited components of the stretch hood system 1, the latter has other sub-components (not shown), for example a cutting device, welding device or film delivery device.
[0056] FIGS. 2a to 2e show successive method steps of a packaging method of the type in question from the prior art, in which method the tubular film portion 3, with the aid of a stretch hood system 1 shown in FIG. 1, is drawn over the article 2 that is to be packaged. The figures show the method section from the insertion of the reefing fingers 7 into the tubular film portion 3 to the reefing of the tubular film portion 3 onto the reefing fingers 7. The figures are simplified in the sense that the stretch hood system 1 is viewed from above and not all components of the stretch hood system 1 are depicted.
[0057] Firstly, a certain portion of the tubular film in the form of the tubular film portion 3 is driven downward by the film supply device 5 and made available. It is then opened with the aid of the tube-opening device 15. For this purpose, the four suction boxes 18 of the tube-opening device 15 move toward the tubular film portion 3 which is hanging down loosely but is still folded together, so as to spread the tubular film portion 3 slightly apart by way of an underpressure. The tubular film portion 3 is then clamped by the holding devices 16 and thereby additionally secured. The suction boxes 18 then move apart and open the tubular film portion 3.
[0058] As is shown in FIG. 2a, the reefing fingers 7 thereafter move from below into the tubular film portion 3, which is held in position by the tube-opening device 15. The tubular film portion 3 has an almost rectangular cross section, since it is kept clamped at the four outer corners by the respective holding devices 16 of the suction boxes 18. The reefing fingers 7, during insertion, maintain a sufficient distance from the tubular film portion 3 in order not to damage the latter. At the respective four corners, the reefing drives 9a are positioned outside the tubular film portion 3 with a sufficient distance from the tubular film portion 3. The suction boxes 18 of the tube-opening device 15 are each located between the reefing fingers 7 and the reefing drives 9a. It is therefore impossible for the reefing drives 9a to be moved too early to the reefing fingers 7.
[0059] After the reefing fingers 7 have been inserted in the tubular film portion 3, the tubular film portion 3 is released by the holding devices 16, as is indicated by the arrows A in FIG. 2b. The position of the reefing fingers 7 and of the reefing drives 9a remains unchanged.
[0060] Thereafter, as is indicated by the arrows B and C in FIG. 2c, the suction boxes 18 move away from the tubular film portion 3. In doing so, two respective suction boxes 18 on one side of the tubular film portion 3 move horizontally toward each other (arrows C) and outward (arrows B) to free the space between the reefing fingers 7 and the reefing drives 9a. This space is later needed to enable the reefing drives 9a to move to the reefing fingers 7. In this method step, the tubular film portion 3 is held only loosely by the reefing fingers 7. In this way, the tubular film portion 3 loses much stability, since it is no longer held in position by the suction boxes 18 with their holding devices 16.
[0061] As is indicated by the arrows D in FIG. 2d, the reefing fingers 7 thereafter move to a reefing position, while the suction boxes 18 move farther away from the tubular film portion 3. In the reefing position, the tubular film portion 3 is extended with slight tensioning by the four reefing fingers 7. For this purpose, the four reefing fingers 7 move in the direction of the four corners of the tubular film portion 3. It is thus now possible to reef the tubular film portion 3 onto the reefing fingers 7.
[0062] Once the tubular film portion 3 bears on the reefing fingers 7, the reefing drives 9a of the reefing device 8 move to the reefing fingers 7 and begin reefing the tubular film portion 3 onto the reefing fingers 7. This method step is indicated by the arrows E in FIG. 2e. In this connection, the reefing drives 9a drive the reefing rollers 9b. In addition, the suction boxes 18 of the tube-opening device 15 move farther away from the tubular film portion 3.
[0063] The reefing is temporarily interrupted to cut off the tubular film portion 3 and weld it in the upper area of the machine frame 4 with the aid of a welding device. Thereafter, the tubular film portion 3 reefed onto the reefing fingers 7 can be drawn over the article 2 by the drawing-over device 6. For this purpose, the reefing fingers 7 of the drawing-over device 6 first of all move apart from each other again, as a result of which the tubular film portion 3 is further extended. The drawing-over device 6 moves downward and draws the film over the article 2 inside the machine frame 4. The tubular film portion 3 is unreefed again from the reefing fingers 7.
[0064] A stretch hood system 1 in a first illustrative embodiment according to the present disclosure is described below before a discussion of the packaging method according to the present disclosure. FIG. 3 shows a perspective view of this stretch hood system 1. Components corresponding to those of the stretch hood system in FIG. 1 are provided here with the same reference signs. The stretch hood system 1 of FIG. 3 differs from the prior art in that here an inflating device 11 is additionally arranged inside the reefing fingers 7. It is thereby possible to at least partially inflate the tubular film portion 3.
[0065] FIGS. 4a to 4e show successive steps, of the method section shown in FIGS. 2a to 2e, of a packaging method in a first illustrative embodiment according to the present disclosure, using the stretch hood system 1 shown in FIG. 3. The simplified views and individual steps correspond to those of the steps of FIGS. 2a to 2e, with the difference that the tubular film portion 3 is at least partially inflated by the inflating device 11 during these method steps. If possible, it is inflated to such a degree that any folds in the tubular film portion 3 are already smoothed out by the inflation.
[0066] Firstly, the tubular film portion 3 is made available and opened in the manner known from the prior art. However, as is shown in FIG. 4a, during the insertion of the reefing fingers 7 into the tubular film portion 3, the latter is inflated by way of the inflating device 11. In this way, a corresponding width of the opening of the tubular film portion 3 is generated and the reefing fingers 7 can be inserted farther than hitherto into the fold-free tubular film portion 3. The previously rectangular cross section of the tubular film portion 3 is stabilized in terms of its shape by the inflation and is extended laterally circularly at least at the front faces. It is thereby possible that the suction boxes 18 and holding devices 16 of the tube-opening device 15 can grip the tubular film portion 3 farther inward than previously in the prior art. This creates space for the reefing fingers 7, so as to be able to insert them directly into the tubular film portion 3. The suction boxes 18 are thus no longer located between the reefing drives 9a and the reefing fingers 7 to fix the outer corners of the tubular film portion 3. Damage to the tubular film portion 3 by the reefing fingers 7 is thus avoided by the inflation, while at the same time there is already sufficient space to be able to move the reefing drives 9a to the reefing fingers 7 much earlier.
[0067] The arrows A in FIG. 4b indicate how the holding devices 16 of the tube-opening device 15 then release the tubular film portion 3 again. The tubular film portion 3 is further inflated and stabilized by the inflating device 11.
[0068] The suction boxes 18 of the tube-opening device 15 are then moved away from the tubular film portion 3, as is indicated by the arrows B in FIG. 4c. In contrast to FIG. 2c, it is not necessary here that two respective suction boxes 18 on one side move toward each other. The area between reefing drive 9a and the reefing finger 7 is not in fact blocked by the suction boxes 18. Thus, these have to move away only in the horizontal direction. Moreover, as a result of the inflation still carried out, the tubular film portion 3 maintains its stable and as far as possible smoothed shape, which is not the case in FIG. 2c.
[0069] As is shown by the arrows D in FIG. 4d, in the next step the reefing fingers 7 move to the tubular film portion 3. The tubular film portion 3 comes to bear on the reefing fingers 7 (reefing position). It can be seen clearly here that, on account of the lateral extension of the tubular film portion 3, the reefing fingers 7 are able to receive the tubular film portion 3 in a way which, compared to previously, is gentler on the material. Since the tubular film portion 3 no longer has strongly pronounced corners resulting from the opening procedure, the load to which the tubular film portion 3 is subject is reduced. Moreover, the reefing fingers 7 bear smoothly on the film. This reduces the risk of superposed folds, which place a considerable load on the film during the extension. Moreover, by virtue of the stable shape of the tubular film portion 3, the suction boxes 18 are able to move away simultaneously from the tubular film portion 3 (arrows B).
[0070] As has already been indicated in FIG. 2e, the arrows E in FIG. 4e show how the reefing drives 9a move to the reefing fingers 7, in order thereafter to reef the tubular film portion 3 onto the reefing fingers 7.
[0071] The tubular film portion 3 is also inflated during the reefing. This has the effect that the tubular film portion 3 can be reefed onto the reefing fingers 7 in a way that is particularly gentle on material. An air cushion caused by the inflation develops between the tubular film portion 3 and the reefing fingers 7, and the tubular film portion 3 slides on this air cushion during the reefing. At the same time, the weld seam of the tubular film portion 3 is cooled, which more quickly increases the strength.
[0072] The subsequent method steps up to the covering of the article 2 correspond to those from the prior art. By way of the measures described, this method step is much less prone to interference than has previously been the case. Moreover, on account of the much more precise folding during the reefing, damage to the tubular film 3 during more rapid unreefing can be avoided. The packaging method according to the present disclosure is therefore quicker, while permitting a higher quality of packaging. Overall, a particularly efficient packaging method is thus made available.
[0073] The stretch hood system 1, according to the present disclosure, of FIG. 3 is once again described in detail below during various method steps. FIG. 5 therefore shows a perspective view of a detail of the stretch hood system 1 obliquely from below upward, during the method step in FIG. 4a. For reasons of clarity, not all the components are shown here. The same components are provided with the same reference signs.
[0074] The reefing device 8 of the stretch hood system 1 is in particular shown in more detail. In the present illustrative embodiment, the reefing device 8 is arranged at the four reefing fingers 7 of the drawing-over device 6. The reefing fingers 7 are adjustable in terms of their position both horizontally and also vertically. Moreover, each reefing finger 7 is individually controllable, such that a symmetrical or simultaneous movement of the individual reefing fingers 7 is also possible.
[0075] A reefing drive 9a is arranged on each of the horizontal portions of the reefing fingers 7. With the aid of the reefing drives 9a, it is possible to reef the required length of the tubular film portion 3 onto the reefing fingers 7. The reefing drives 9a are for this purpose displaceable along the reefing fingers 7, such that, after the reefing fingers 7 each bear with a reefing-on surface 10 at the tubular film portion 3, the reefing drives 9a can each move from outside toward the tubular film portion 3 and, by way of a conveying mechanism (in the present case a reefing roller 9b), can begin the reefing procedure.
[0076] The inflating device 11 is arranged here inside the reefing fingers 7. In the example shown here, constituent parts of the inflating device 11 include an air inlet 12, behind which a fan sits, from which the suctioned air is guided through a channel inside the respective reefing finger 7 to the outlet opening 13 at the horizontal end of the reefing finger 7. Moreover, a selectively closable closure element 14, designed here as a flap, is arranged at the horizontal end of the reefing finger 7, which closure element 14 closes the outlet opening 13 as desired or opens it to a certain degree. With the aid of the closure element 14, it is possible for the resulting air stream, generated by the inflating device 11, to be deflected in the direction of the interior of the tubular film portion 3.
[0077] By way of an adjusting device, it is possible to throttle and adapt the volumetric flow that is blown into the tubular film portion 3. For this purpose, the adjusting device has a throttle element, which is designed as a flap. In this illustrative embodiment, the throttle element thus corresponds to the closure element 14. The volumetric flow can thus be adjusted according to the material property and the film thickness. In this way, damage and tears in the tubular film portion 3 can be avoided, even when different film thicknesses are used.
[0078] The tube-opening device 15 here includes four individual suction boxes 18, which are horizontally and vertically movable independently of the drawing-over device 6. Thus, the suction boxes 18 can be placed individually onto the still unopened tubular film portion 3 and draw the latter apart. In this connection, the suction boxes 18 accordingly approach the tubular film portion 3 symmetrically from opposite sides and, by generating an underpressure, achieve a bearing of the tubular film of the tubular film portion 3 on the respective suction box 18. The suction boxes 18 then move apart again and thereby open the tubular film portion 3.
[0079] The holding devices 16 at the suction boxes 18 are each designed as a flap mechanism. On account of the film being stabilized by the inflation during opening, the use of the holding devices 16 is optional and thus no longer absolutely necessary for performing the packaging method according to the present disclosure.
[0080] As FIG. 4a has already shown, FIG. 5 once again illustrates how the inflation of the tubular film portion 3 stabilizes the latter and extends it laterally. The reefing fingers 7 can thus be safely inserted from below into the tubular film portion 3 without causing damage to the latter.
[0081] FIG. 6 shows a further perspective view according to FIG. 5, during the method step in FIG. 4e. The reefing fingers 7 are already inserted in the tubular film portion 3 and bear on the latter (reefing position). The reefing drives 9a move to the reefing fingers 7 to reef the tubular film portion 3 onto the reefing fingers 7. The suction boxes 18 of the tube-opening device 15 have already moved away and are therefore no longer depicted. As a result of the inflation, the tubular film portion 3 is in a much smoother state than before, and therefore complications can be avoided during reefing and unreefing.
[0082] FIG. 7 shows a further perspective view during reefing. The closure elements 14 of the inflating device 11 at the reefing fingers 7 are opened to inflate the tubular film portion 3. In this way, the tubular film portion 3 can be reefed onto the reefing-on surfaces 10 of the reefing fingers 7 uniformly and more or less without folds. For this purpose, the reefing drives 9a are moved to the reefing fingers 7 to permit reefing with the aid of the conveying mechanism.
[0083] FIG. 8 once again shows the perspective view during unreefing. After the unreefing position has been adopted, the drawing-over device 6 moves downward to cover the article 2 with the tubular film portion 3. The tubular film portion 3 is unreefed again from the reefing fingers 7 by way of the reefing drives 9a. The reefing drives 9a are thus still moved up to the reefing fingers 7 to assist the drawing-off of the tubular film portion 3 with the aid of the reefing rollers 9b. The closure elements 14 of the inflating device 11 remain closed, since the tubular film portion 3 meanwhile is not inflated in the variant shown here.
[0084] FIG. 9 shows in more detail the end of the horizontal portion of the reefing finger 7 and also the vertical portion of the reefing finger 7. The closure element 14 is opened in this state to lead air accordingly from the outlet opening 13 in the direction of the tubular film portion 3. By virtue of the arrangement of the closure element 14, it is now possible to guide the air stream vertically upward in the direction of the tubular film portion 3. Thus, the inflating device 11 extends into each of the four reefing fingers 7 to ensure, by inflation, a suitable stability of the tubular film portion 3 precisely at these locations. This therefore permits safe insertion of the reefing fingers 7 into the tubular film portion 3 and reduces the stress on the material during reefing and/or unreefing.
[0085] In the illustrative embodiment shown here, the closure element 14 is arranged on the side of the reefing finger 7 opposite the reefing-on surface 10. The reefing-on surface 10 includes two individual surfaces 10a which are slightly angled and are provided with wear protection strips. A guide roller 17 is arranged between the two subsidiary surfaces of the reefing-on surface 10 at the end of the vertical portion of the reefing finger 7, such that the tubular film portion 3 can be reefed uniformly and without damage by the terminating edges of the vertical portion of the reefing finger 7.
[0086] The horizontal portion of the reefing finger 7 shown in FIG. 9 moreover has a pressure-increasing mechanism. It is thus possible to ensure that air is suitably aspirated through the air inlet 12 and can emerge with suitable pressure through the outlet opening 13. Since the pressure-increasing mechanism is arranged inside the horizontal portion of the reefing finger 7, it is not shown explicitly in FIG. 3.
[0087] FIGS. 10a to 10d shows successive steps of a packaging method according to the present disclosure in a second illustrative embodiment, using the stretch hood system 1 shown in FIG. 3. The method section corresponds to that of the first illustrative embodiment in FIGS. 4a to -4e, this method section being reduced to four steps. All of the aforementioned advantages afforded by the inflation of the tubular film portion 3 in FIGS. 4a to 4e apply accordingly to this illustrative embodiment. Identical components are provided with the same reference signs.
[0088] The insertion of the reefing fingers 7 into the tubular film portion 3 as shown in FIG. 10a corresponds to the first illustrative embodiment in FIG. 4a. As is shown in FIG. 10b, the holding devices 16 then free the tubular film portion 3 again (arrows A) in accordance with FIG. 4b. However, in contrast to FIG. 4b, the reefing fingers 7 already move at the same time to the reefing position (arrows D) to speed up the method.
[0089] As is shown in FIG. 10c, the reefing drives 9a then move to the reefing fingers 7 (arrows E) to reef the tubular film portion 3 onto the reefing fingers 7. The suction boxes 18 of the tube-opening device 15 are still located at the tubular film portion 3 but do not block the space between the reefing fingers 7 and the reefing drives 9a, as is known from the prior art in FIG. 2b.
[0090] FIG. 10d shows the last step of the method section. While the suction boxes 18 of the tube-opening device 15 move away in the horizontal direction (arrows B), perpendicularly from the tubular film portion, the reefing drives 9a can already begin to reef the tubular film portion 3 onto the reefing fingers 7. By virtue of the fact that the reefing fingers 7 move earlier to the reefing position and the reefing drives 9a move earlier to the reefing fingers 7, the method sequence described above can thus be sped up.
[0091] FIG. 11 shows a tubular film portion 3 in the opening system of a conventional stretch hood system 1. For better insertion of the reefing fingers (not shown here), the holding devices 16 (here designed for example as suction boxes 18) are provided with a recess. In this way, the holding devices 16 have an L-shaped appearance. On account of this recess, however, the lower edge of the tubular film portion 3 curves in earlier than would be the case in holding devices having no such recess.
[0092] As can be seen by comparison with the embodiment according to the present disclosure shown in FIG. 12, this disadvantage is compensated, in the method according to the present disclosure and in a device according to the present disclosure, by the inflation of the tubular film portion 3 during the opening procedure. Here, the open edge is extended and the tube stabilized by the inflation. It does not curve inward as in FIG. 11 but instead outward. In this way, the reefing fingers have more space during insertion and can be moved closer and more exactly to the tube.
[0093] Various changes and modifications to the present embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
