EP0544704B2 - Device for wrapping a packaging unit - Google Patents

Abstract

There exist devices for wrapping a packaging unit (14) of mineral wool plates (15) or a mineral wool roll that have a conveyor (1, 2) for the packaging unit, a foil roll (3) spaced above and a foil roll (4) spaced below the conveyor (1, 2), as well as a welding beam (10) and a stop beam (13) movable towards each other in such a way that they clamp between them the ends of the wrap (26) and weld them together. In addition, a cutter cuts the transversal weld (7) thus produced and welds together the ends of the wrap on the one hand and the ends (5, 6) of the foils that can be drawn from the foil rolls (3, 4). Such packaging units are extremely bulky and difficult to handle. In order to obtain a device capable of producing such a wrap, so that the packaging units can be easily handled, the welding beam (10) and the stop beam (13) are so wide, seen in the direction (16) of transport of the packaging unit (14), whereas the welding beam (10) is provided with at least two spaced apart heating zones (18, 19), that a carrying handle (23) is formed at the periphery of the wrap (26).

Description

The invention relates to a device for wrapping a bulky packaging unit, which consists of mineral wool sheets or a mineral wool roll, with a conveyor device for the packaging unit, a film roll at a distance above and a film roll below the conveyor, a welding bar and a stop bar , which can be guided against each other in such a way that the ends of the casing can be clamped and welded to one another, and furthermore with a separating device which is designed in such a way that the transverse weld seam formed is severed and on the one hand the ends of the casing and on the other hand the ends of the films that can be peeled off from the film rolls are welded to one another, the film ends including the weld seam each forming a vertical curtain, against which the packaging unit can be displaced to form the wrapper.

Devices of the aforementioned type are known in practice. They work in such a way that packaging units, which consist, for example, of packages of mineral wool slabs stacked one on top of the other, are fed in rows one after the other by means of a conveyor device. The ends of the films which can be pulled off or unwound from an upper and a lower film roll are connected to one another by a weld seam, so that a curtain is formed to a certain extent. The packaging unit in question is then pushed against this curtain, so that film parts are drawn off both from the upper and from the lower film roll. The shifting movement takes place until the packaging unit is moved over the stop bar, taking the film with it. The packaging unit, for example the package of mineral wool panels, then remains at a distance of about 10 to 20 cm behind the stop bar. At this time, the packaging unit is encased on three sides, approximately U-shaped, by the plastic film. In this position, the welding bar moves against the stop bar and pulls another part of the plastic film from the adjacent film roll. In the stop position, an electrical heater located in the welding bar is heated up, so that a weld seam running transversely to the transport direction is formed. After the very rapid cooling of the weld seam, it is separated in the middle in such a way that, on the one hand, the packaging unit remains completely wrapped in the plastic film and, on the other hand, the ends of the film parts unwound from the film rolls are welded together, so that a curtain is formed again . The welding bar then moves back to the starting position and the wrapping process can be repeated. Following this Operation, the wrapped packaging unit is fed to a shrink tunnel in which the plastic film is heated and shrunk when it cools down again so that it lies tightly over the entire circumference of the packaging unit. The film wrapping of the fully packaged packaging unit then has two weld seams running over the entire width. A shrink film made of a polyethylene material is used as the plastic film.

Such packaging units are generally extremely bulky. Since the plastic film is also very smooth, the packaging units are difficult to handle. However, they usually have to be stacked in large quantities by hand for warehousing, reloaded in trucks, unloaded at the dealer or on the construction site and finally transported for processing. In these operations, the bulky packaging units must be grasped, raised and carried further by the artisans concerned with their arms spread wide, and often they slip off the flat plastic film and fall to the floor, so that the plastic film can be damaged.

In contrast, the invention is based on the object of providing a device with the aid of which such a covering can be produced that the packaging units can be handled easily.

The object is achieved by the features of claim 1.

Advantageous refinements of the device according to the invention result from subclaims 2 to 6.

The invention further relates to a packaging unit according to claim 7.

Advantageous configurations of the packaging unit result from subclaims 8 and 9.

• Fig. 1 eine Seitenansicht einer Vorrichtung in Anfangs-Betriebsstellung,
• Fig. 2 eine Vorrichtung gemäß Fig. 1, jedoch in einer Zwischen-Betriebsstellung,
• Fig. 3 die Vorrichtung gemäß Fig. 1 oder 2 in einer Betriebsstellung während des Schweißvorganges,
• Fig. 4 eine Seitenansicht entsprechend Fig. 3, jedoch in einer anderen Ausführung der Vorrichtung,
• Fig. 5 die Vorrichtung gemäß Fig. 4 in einer Betriebsstellung nach Beendigung des Schweißvorganges,
• Fig. 6 eine Draufsicht auf eine umhüllte Verpackungseinheit,
• Fig. 7 einen Teilquerschnitt zu Fig. 6 durch die Tragelasche in vergrößertem Maßstab und
• Fig. 8 einen Teilquerschnitt zu Fig. 6 gemäß Schnittlinie VIII-VIII in vergrößertem Maßstab.

In the drawing, embodiments of the invention are shown in the diagram, namely show

• 1 is a side view of a device in the initial operating position,
• 2 shows a device according to FIG. 1, but in an intermediate operating position,
• 3 shows the device according to FIG. 1 or 2 in an operating position during the welding process,
• 4 is a side view corresponding to FIG. 3, but in another embodiment of the device,
• 5 shows the device according to FIG. 4 in an operating position after completion of the welding process,
• 6 is a plan view of a wrapped packaging unit,
• Fig. 7 is a partial cross section to Fig. 6 through the carrying tab on an enlarged scale and
• Fig. 8 is a partial cross section to Fig. 6 along section line VIII-VIII on an enlarged scale.

The same reference numerals have been used for the same or equivalent parts to the exemplary embodiments explained below, so that the explanations in this regard relate to the various embodiments. In the exemplary embodiment according to FIGS. 1 to 3, two conveying devices 1, 2 are provided in the form of transport roller conveyors. Instead of the conveyor roller conveyors, other suitable conveying devices, e.g. B. endless conveyor belts are used. Between the two conveying devices there is a fixed stop bar 13, the upper stop surface of which is at the level of the upper conveying surface of the conveying devices 1, 2. A film roll 3 is rotatably mounted vertically at a distance above the transport roller conveyor 1. Another film roll 4 is also rotatably arranged below the transport roller conveyor 1. A film 5 can be pulled off the upper film roll 3 and a further film 6 can be pulled off the lower film roll 4, the film rolls each rotating in the direction of the arrows 20 and 21. The ends of the two film webs 5, 6 are connected to one another by a weld 7, which runs perpendicular to the image plane of FIG. 1 and extends over the entire width of the film webs. In the vicinity of the film rolls there are deflection rolls 8 and 9 which are arranged such that the lower film web 6 passes through a gap between the conveyor device 1 and the stop beam 13.

In the initial operating position according to FIG. 1 there is a packaging unit on the transport roller conveyor 1 14, which in this embodiment consists of a stack or a package of mineral wool panels 15, which are therefore stacked on top of one another. There is also a welding bar 10 which can be moved up and down in the direction of the arrow by means of a rod 11 shown in simplified form. The lifting height of the welding bar 10 is greater than the height of the packaging unit 14. In the operating position according to FIG. 1, the welding bar is in its uppermost position. If the packaging unit 14 or the stack of plates is now moved in the direction of arrow 16 into the operating position according to FIG. 2, part of the film web 5, 6 is pulled off from the two film rolls 3, 4, so that in this operating position the underside first and the front end of the packaging unit lying in the conveying direction is covered by the plastic film. In the next step, the welding bar 10 is moved over the lifting height up to the stop bar 13, so that the operating position according to FIG. 3 results. During the lifting movement of the welding bar, the film web 5 lifts off a guide roller 17. The packaging unit is encased on the entire circumference by the plastic film.

As illustrated in FIGS. 1 to 3 and also FIGS. 4 and 5 for a further exemplary embodiment, the welding bar 10 and the stop bar 13, as seen in the conveying direction 16 of the packaging unit 14, are so wide and the welding bar 10 is at least two in width Heating zones 18, 19 which are spaced apart from each other provide that a carrying strap 23 is formed on the circumference of the envelope 26 during the welding process. The heating zone 18 can advantageously also be double, so that this results in two weld seams running closely next to one another, between which the separation process can be carried out. According to FIG. 3, the film part of the envelope 26 runs on the rear end face, exaggerated for the sake of clarity, at an acute angle, so that there is initially a wedge-shaped space. After the packaging unit has been separated, it is fed to a shrink tunnel, not shown, where the plastic film is shrunk so that it lies tightly against the packaging unit over the entire circumference.

In the exemplary embodiment according to FIGS. 4 and 5, both the welding bar 10 and the stop bar 13 are movably arranged by means of rods 11 and 22 which are shown in simplified form, in such a way that the two bars are approximately at the central height of the packaging unit 14 (FIG. 4) meet.

The known, either combined with the stop bar or separately arranged separator is controlled so that it is a short time after the welds and after cooling it takes effect. According to the invention, the separating device advantageously has at least one additional tool for punching a handle opening into the carrying strap 23. In the embodiment of FIG. 6, three handle openings 27, 28 and 29 are provided. To produce them, three additional tools are then arranged in such a way that a central grip opening 28 and two grip openings 27 and 29 located near the edge of the carrying strap 23 are created. The additional tools advantageously have a substantially oval cut edge, so that the handle openings allow easy handling.

As illustrated in FIGS. 6 to 8, the carrying strap 23 is delimited on both sides by weld seams 24 and 25. A further oval weld seam 30 can be provided at the edge of the handle openings for additional reinforcement. To produce them, the welding bar 10 has an additional oval heating zone near the edge of the respective handle opening 27, 28 or 29. The foil parts inside the handle openings can be completely punched out. But it is also possible to design the cutting edge of the additional tool so that it extends only over the two curves 31 and 32 and a connecting edge 33 between the two curves, so that the punched-out film parts can be folded over the other opposite connecting edge 34. The folding can also be carried out around the outer connecting edge 33 when the tool is appropriately turned over.

By means of the devices described above, a packaging unit is obtained from mineral wool sheets or alternatively also from a mineral wool roll, which is rolled up from a web, with a covering 26, which consists of a shrinkable plastic film and the ends of which are connected to one another by a weld seam and an outward-facing carrying strap 23 being flanged to the weld seam. For manufacturing reasons, the carrying lug 23, as described above, is formed from the extended ends of the plastic film, the outer edge of the carrying lug also expediently having a further weld seam 24. The carrying strap 23 has one or more grip openings 27, 28 and 29 which are surrounded by weld seams 30 for reinforcement. It is generally sufficient to provide only a single central handle opening. However, if the packaging units are particularly large and heavy, the two outer handle openings can be provided instead of or in addition to the central handle opening so that two people can attack and cause particularly rapid stacking and loading etc.

In the case of a cuboid or cubic packaging unit, the carrying strap can be formed along one of its edges, as can be seen in FIG. 3 results. In the more expedient embodiment, the carrying tab 23 is, however, molded onto a covered surface in the middle of FIG. 5.

Claims (10)

1. Device for wrapping a bulky packaging unit (14), which consists of mineral wool sheets (15) or of a mineral wool roll, with a conveying device (1, 2) for the packaging unit, a roll (3) of sheeting at a distance above and a roll (4) of sheeting below the conveying device (1, 2), a welding bar (10) and an abutment bar (13), which can be guided towards each other so that between the latter the ends of the wrapping (26) can be clamped and welded to each other, and furthermore with a separating device, which is designed so that the transversely extending welded seam (7) formed is separated and on one side the ends of the wrapping and on the other side the ends (5, 6) of the sheeting able to be withdrawn from the rolls of sheeting (3, 4) are welded to each other, the ends of the sheeting (5, 6) including the welded seam respectively forming a vertical curtain, towards which the packaging unit can be moved thus forming the wrapping, characterised by the combination with the further features, that the welding bar (10) and the abutment bar (13), seen in the conveying direction (16) of the packaging unit (14), are constructed to be so wide and the welding bar (10) is provided with at least two heating zones (18, 19) extending at a distance apart, that a carrying flap (23) is formed on the periphery of the wrapping (26) and that the separating device comprises three additional tools for producing one central gripping opening (28) and two gripping openings (27, 29) near the rim of the carrying flap (23) and that close to the edge of at least the central gripping opening (28) the welding bar (10) comprises one additional oval heating zone.
2. Device according to claim 1, characterised in that the welding bar near the rim of all three gripping openings (27, 28, 29) includes additional oval heating zones.
3. Device according to claim 1 or 2, characterised in that the additional tools have a substantially oval cutting edge.
4. Device according to claim 4, characterised in that the cutting edge extends over the two rounded portions (31, 32) and a connecting edge (33) between the two rounded portions, so that the sheeting parts stamped out can be folded around the other opposite connecting edge (34).
5. Device according to one of the preceding claims, characterised in that the welding bar (10) can be moved by a lifting height, which is greater than the height of the packaging unit (14), as far as the abutment bar (13), and that the abutment bar (13) is arranged in a stationary manner with the abutment surface at the level of the conveying device (1, 2).
6. Device according to one of claims 1 to 4, characterised in that both the welding bar (10) as well as the abutment bar (13) are movable so that the bars encounter each other approximately at the mid height of the packaging unit (14).
7. Packaging unit consisting of bulky mineral wool sheets (15) or of a bulky mineral wool roll with a wrapping (26) open on te end face, which wrapping consists of two pieces of shrinkable plastic sheeting, whereof the ends are connected to each other by two welding seams (7, 25), characterised by the combination with the further features, that flange-connected to one welding seam (25) is a carrying flap (23) pointing outwards, that the carrying flap (23) is formed from the extended ends of the plastic sheeting, that the outer rim of the carrying flap (23) includes a further welding seam (24), and that the carrying flap (23) comprises at least one central gripping opening (28) and two gripping openings (27, 29) arranged close to the ends of the carrying flap, wherein at least the central gripping opening (28) is surrounded by an oval welding seam (30).
8. Packaging unit according to claim 7, characterised in that the three gripping openings (27, 28, 29) are all surrounded by oval welding seams (30).
9. Packaging unit according to claim 7 or 8, characterised in that in cuboid-shaped packaging unit, the carrying flap (23) is formed integrally along one of the edges.
10. Packaging unit according to claim 7 or 8, characterised in that in a cuboid-shaped packaging unit (14) the carrying flap (23) is integrally formed at the mid height of one side face.

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