METHOD FOR SHAPING A FLAT WEB MATERIAL, AND DEVICE

Abstract

The aim of the invention is to shape a flat web material (12) into a constant three-dimensional structure with a plurality of folds along differently oriented folding lines and with elevations and depressions. This is achieved in that the flat web material is inserted between a lower holding die (20b) and an upper holding die (20a), which are largely flat, consist of a flat material, and have pre-shaped bending lines that lie over one another in a precise manner when lying against the flat web material. A lower (30b) and an upper molding die (30a) are then guided thereto and brought into position, said molding dies consisting of a flat material with specified folding lines which oppose one another in a precise manner. The molding dies (30a, 30b) have a shape corresponding to the three-dimensional structure to be produced, and the molding die folding lines oriented towards the holding dies or pointing towards the holding dies match the bending lines of the holding dies, wherein the folding lines can lie against the holding dies.

Claims

1. A method for shaping a flat web material, wherein said flat web material is largely flat or smooth and level in an initial state and, when folded in a final state, is in a periodic three-dimensional structure, said periodic three-dimensional structure having a multiplicity of folds along differently oriented folding lines and having elevations and depressions, said method having the following steps: said flat web material is inserted between a lower holding die and an upper holding die, wherein said holding dies are composed of flat material and have preformed kink lines, said kink lines being identical on said two holding dies and lie precisely one above the other when they are resting on said flat web material, moving a lower shaping die and an upper shaping die up to said holding dies from below and from above respectively, wherein said shaping dies are composed of flat material with predetermined bending lines, said holding dies are largely level during an insertion of said flat web material and also as said shaping dies are moved up, said shaping dies have bending lines precisely corresponding to one another or precisely lying opposite one another, with identical bendings along said bending lines, wherein said shaping dies are not flat but are raised by bending along said bending lines or have a shape corresponding to said three-dimensional structure to be produced with said flat web material, wherein at least some of said bending lines of said shaping dies coincide with some of said kink lines of said holding dies.

2. The method as claimed in claim 1, wherein, as said method progresses, said shaping dies largely retain their shape and/or said holding dies are deformed and are raised in a corresponding shape with elevations and depressions along said kink lines of said holding dies.

3. The method as claimed in claim 1, wherein, as said shaping dies are moved up to said holding dies, a plane situated in a middle between said shaping dies is not yet touched by said shaping dies, wherein, as said method progresses, said shaping dies are moved ever further toward one another or elevations along bending lines of one said shaping die engage in depressions along bending lines of said other shaping die, wherein said holding dies with said flat web material therebetween are deformed or raised in a corresponding shape with elevations and depressions along said bending lines and thus along said kink lines of said holding dies as said shaping dies are increasingly pressed together or as they increasingly move one into another, as a result of which said folding lines of said flat web material are obtained along said bending lines and said kink lines.

4. The method as claimed in claim 1, wherein pressing together of said shaping dies takes place along a throughput path in a continuous process by means of a plurality of circulating pressure means arranged in series.

5. The method as claimed in claim 1, wherein, in a case where said method is carried out as a continuous process, said holding dies are synchronized with said flat web material, before said shaping dies are moved up.

6. The method as claimed in claim 1, wherein, in that a case where said method is carried out as a continuous process, synchronization between said upper shaping die and said lower shaping die is performed directly after said shaping dies have been moved up to said holding dies and placed in contact, preferably by means of rotating or circulating synchronization means with an external shape corresponding to said structure or said shape of said shaping die.

7. The method as claimed in claim 1, wherein, in a state just before said shaping dies are moved away from said holding dies, bending lines extend along elevations on said shaping dies along all said kink lines of said holding dies and all said folding lines of said flat web material.

8. The method as claimed in claim 1, wherein, after said shaping dies have been moved away from said holding dies, a further or even more pronounced deformation of said flat web material takes place between said holding dies by means of positively engaged conveyance, by means of engaging conveying means, of said compound structure comprising said holding dies and said flat web material, with compression in a throughput direction or with a shortening in length.

9. The method as claimed in claim 1, wherein said folding lines of said flat web material extend only precisely in two or three directions, wherein said directions are preferably at an angle of between 60 and 120 to one another.

10. The method as claimed in claim 1, wherein said flat web material is single-ply or not folded upon itself in said initial state and in said final state.

11. A device for carrying out said method as claimed in claim 1, wherein said device has a throughput path along which said flat web material to be shaped passes, wherein a holding die, and above it a shaping die, are arranged from above on said throughput path, and wherein a holding die and below it a shaping die are arranged on said throughput path from below, wherein said holding dies are composed of flat material and have pre-formed kink lines being are identical on said two holding dies and lie precisely one above another when resting on said flat web material, and wherein said shaping dies are composed of flat material and have preformed bending lines corresponding precisely to one another or lie precisely opposite one another, with identical bending along said bending lines, wherein said shaping dies are raised by bending along said bending lines or have a shape corresponding to said three-dimensional structure to be produced with said flat web material, wherein at least some of said bending lines of said shaping dies coincide with kink lines of said holding dies.

12. The device as claimed in claim 11, wherein at least one deformation region with pressure means for deformation, is provided along said throughput path.

13. The device as claimed in claim 11 wherein, after said shaping dies have been moved up into contact with said holding dies and before a substantial deformation of said holding dies, a vibration device is provided or vibrates said arrangement somewhat.

14. The device as claimed in claim 11, wherein said holding dies and/or said shaping dies are circulating belts with a length of more than twice said throughput path for said flat web material, which is a long web or a continuous web, wherein said belts of said holding die each run around or surround said belts of said shaping die.

15. The device as claimed in claim 11, wherein lateral pressing means are provided on the side of said throughput path for pressing together said holding dies laterally with said flat web material between them and/or pressing together said shaping dies laterally with said holding dies and said flat web material between them.

16. The method as claimed in claim 4, wherein said pressure means are pressure means circulating in a manner of belts.

17. The method as claimed in claim 4, wherein a pass height between said successive pressure means in said throughput direction decreases or becomes smaller.

18. The method as claimed in claim 8, wherein said conveying means are circulating conveying means and have an external structure or shape corresponding to a finished shape of said flat web material in a final state.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Illustrative embodiments of the invention are shown schematically in the drawings and are explained in greater detail below. In the drawings:

[0031] FIG. 1 shows a schematic side view of a device for shaping a flat web material,

[0032] FIG. 2 shows a first embodiment of shaping belts in the form of double conveyor belts with a constant spacing relative to one another,

[0033] FIG. 3 shows a modification of the deformation belts in the form of double conveyor belts from FIG. 2 with a decreasing spacing relative to one another in the throughput direction,

[0034] FIGS. 4 to 6 show an illustration in three stages of the shaping of the flat web material between the upper and lower holding dies, which are deformed by upper and lower shaping dies in order to shape the flat web material to raise it into a three-dimensional structure,

[0035] FIGS. 7 to 13 show various final patterns or final shapes of a shaped flat web material in isometric view, plan view and side view and as a unit cell of a plane folding pattern.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0036] FIG. 1 shows a device 11 according to the invention for shaping a flat web material 12, which comes from a material supply 13 in the form of a large roll or the like. In FIG. 1, the flat web material 12 runs from right to left through throughput plane D, which is illustrated by a dotted line on the left and right. The flat web material 12 can be one of those mentioned above, e.g. paper, but can also be thin plastic in the form of film material or thin web material, and can likewise comprise metallic materials such as thin aluminum foil and composite materials. As mentioned at the outset, it can even be slightly corrugated with corrugations of between 0.5 mm and 3 mm. After being unwound from the material supply 13, the flat web material 12 passes through an optionally provided embossing device 15. This can already preemboss the folding lines for subsequent folding or shaping, thus allowing this shaping to be carried out more easily. For this purpose, appropriately known embossing rolls with narrow ridge-type elevations can be used. However, the material can also arrive already preembossed or on a roll.

[0037] There then follows an optionally provided cutting device 16, which carries out a cross cut. In this way, the virtually continuous strip of flat web material 12 can be divided into particular or desired lengths. As an alternative, the flat web material 12 can also be fed in the form of individual sheets. In addition to the cutting device 16 for a cross cut, it is also possible to provide one or two longitudinal cutting devices to cut the flat web material 12 to an appropriate width as well.

[0038] As the next stage, the flat web material 12 passes through a feed region 18. In this region, an upper holding die 20a and a lower holding die 20b are first of all fed in simultaneously or, alternatively, in succession, from above and below, symmetrically with respect to the throughput plane D. These holding dies 20 circulate in large loops largely depicted in dashed lines and are designed as abovementioned continuous belts. For this purpose, they are composed of an appropriately stable plastics material. Combinations of different materials, e.g. metal and plastic, or simply metal with hinges or the like are also conceivable. The holding dies 20a and 20b can be moved up in a flat or smoothed form to the flat web material 12. For this purpose, corresponding smoothing devices, advantageously rolls pressed against one another, can be provided between the extreme left-hand end of the device 11 and the feed region 18. At any event, the holding dies 20a and 20b should come to rest to a large extent flat or over an extended area on the flat web material 12 in the feed region 18. At the same time, this material may already be shaped somewhat out of the flat form.

[0039] Shortly after the holding dies 20a and 20b, the upper shaping die 30a and the lower shaping die 30b are moved up in the feed region 18 in the embodiment of the device shown here. These dies too are continuous belts circulating in the manner of loops with a course which is illustrated largely by dotted lines. In this case, corresponding guiding devices or guide rollers (not shown here) are provided. Unlike the holding dies 20a and 20b, the shaping dies 30a and 30b are not moved up in a largely flat form but, as illustrated, in raised form, that is to say their shape advantageously changes only slightly, e.g. by the 2% to 15% mentioned above. As illustrated in the enlarged form below, the shaping dies 30a and 30b rest by means of their mutually facing points or protruding regions against the outsides of the holding dies 20a and 20b.

[0040] The compound structure comprising the flat web material 12, the holding dies 20a and 20b resting on the latter, and the shaping dies 30a and 30b in turn resting on said holding dies moves to the left in a continuous process and is guided into an optionally provided synchronization device. As described above, it is also possible for the dies and the flat web material to be synchronized in succession in the synchronization. This can mean that synchronization coincides with the feed region 18, and the dies with the flat material are synchronized in pairs or, alternatively, in succession before a further die or a further die pair is moved up. Additional synchronization is important or advantageous especially for the holding dies with the material to ensure that the optional stamped lines coincide with the folding lines of the dies. Synchronization can also be performed by means of rolls, vibrators or the like. The design shown here of the synchronization device has an upper synchronization belt 41a and a lower synchronization belt 41b, which serve to synchronize the dies with one another or bring them into the correspondingly desired position relative to one another and optionally relative to the flat web material, especially the upper and lower shaping dies 30a and 30b. For this purpose, the synchronization belts 41a and 41b can have protruding elevations or spikes which engage in the outsides of the shaping dies 30a and 30b with such precision of location or accuracy of position that they can be positioned as desired relative to one another.

[0041] The synchronization device 40 is followed by a vibration device 43, which is likewise provided only as an option. This can comprise pressure jaws or the like, which are flexible, for example, and which not only compress the compound structure further but also position the dies 20a, 20b and 30a, 30b relative to one another longitudinally and/or transversely with respect to the throughput direction. In particular, as a result, slight deformation of the holding dies 20a and 20b with the flat web material 12 between them in accordance with kink lines of the holding dies can possibly already take place or start.

[0042] An upper first deformation belt 46a and a lower first deformation belt 46b circulate in a subsequent first deformation region 45, as is also illustrated on an enlarged scale in FIGS. 2 and 3. The deformation belts 46a and 46b are largely flat and push the shaping dies 30a and 30b toward one another, as illustrated on an enlarged scale there. They correspond to the pressure means mentioned at the outset.

[0043] The first deformation region 45 is followed by what is referred to as a first contraction region 48, which, although optional, should advantageously be provided. In this region, the compound structure is as it were braked between the first deformation region 45 and a subsequent second deformation region 50 and is thereby compressed or shortened. At the same time, as is apparent from the following illustrations, this causes more pronounced deformation of the flat web material and of the holding dies 20a and 20b by more pronounced raising or shaping out of the throughput plane D.

[0044] After this, the compound structure passes through a second deformation region 50, in which, as in the first deformation region 45, an upper second deformation belt 51a and a lower second deformation belt 51b are provided. These can be of identical design to the deformation belts 46a and 46b in the first deformation region 45 but, as an alternative, they can also be designed in accordance with the other of the two basic possibilities in FIGS. 2 and 3. As can be seen from FIG. 1, the dies 20a, 20b and 30a and 30b, together with the flat web material 12 between them, are raised to a greater extent in the second deformation region 50 and thus deformed to a greater extent. The spacing between the second deformation belts 51a and 51b should also be somewhat less than that between the first deformation belts 46a and 46b.

[0045] As one possibility, it is then possible for yet further deformation regions having further deformation belts that are even less far apart to follow. As an alternative, a first lifting region 53 can follow, in which the shaping dies 30a and 30b are lifted off and can thus be moved away from the holding dies 20a and 20b by being guided away in each case, wherein abovementioned deflection rollers or the like can be provided here.

[0046] In a subsequent third deformation region 55, upper and lower third deformation belts 56a and 56b are once again provided, said belts holding and conveying and, in the process, deforming the holding dies 20a and 20b with the flat web material 12 therebetween between them under pressure. After the third deformation region 55 there follows a fourth deformation region 60 with an upper fourth deformation belt 61a and a lower fourth deformation belt 61b. Technically, it is conceivable that regions 55 and 60 are deformation regions but the principle purpose is to ensure the speed difference by conveying the dies and the flat material at different speeds so that the contraction region 58 works. Between them, a second contraction region 58 can be provided, in which the compound structure passing through is braked even further and is thus shortened and raised or deformed to a greater extent. The region between 50 and 55, i.e. region 53, can additionally also be a contraction region. The deformation belts 56a, 56b and 61a, 61b can be largely level on the upper side thereof, with a rubberized or highly slip proof surface, in order to grip the holding dies 20a and 20b, situated in each case on the outside, with good nonpositive engagement and to convey them. As an alternative, elevations and/or depressions can be provided for conveyance by positive engagement. Whereas the pressure from outside on the compound structure was important in deformation regions 45 and 50 because it has brought about relatively pronounced deformation of the holding dies 20a and 20b with the flat web material 12 between them, the pressure in deformation regions 55 and 60 should not be too great since it otherwise once again compresses the holding dies 20a and 20b with the flat web material 12 between them. Further deformation regions or contraction stages can follow, even after the lifting off of the holding dies.

[0047] In a second liftoff region 63, the holding dies 20a and 20b are then lifted off or moved away from the flat web material 12. Here, the flat web material 12 can then have its final structure or shape, as can be seen on the extreme left in FIG. 1, and in which respect reference is also made to FIGS. 4 to 13. A cutting device 65 can then possibly also be provided, especially if none is provided at the start. Otherwise, the shaped flat web material 12 can be conveyed onward for a use as mentioned at the outset, especially for a component of sandwich construction. In some circumstances, however, a further deformation of the flat web material 12 can generally be performed even after liftoff of the holding dies, e.g. by its being compressed longitudinally and pressed transversely for example. As a further possibility, a hardening region, a tempering region or the like can follow.

[0048] A first possible embodiment of the first deformation region 45 with an upper first deformation belt 46a and a lower first deformation belt 46b is shown on an enlarged scale in FIG. 2. The first deformation belts 46a and 46b have a constant spacing with respect to one another over their length and thus press on the outer ridges 34a and 34b of the upper shaping die 30a and lower shaping die 30b respectively. This has the effect that the compound structure comprising the flat web material 12 and the holding dies 20a and 20b coming from the right are pressed together even more strongly, specifically right at the start as they run into the first deformation region 45 or between the first deformation belts 46a and 46b and also into the second deformation region 50 with belts 51a and 51b. In the next deformation region with its deformation belts as shown in FIG. 1, the spacing between the upper and lower deformation belt can then, in turn, be somewhat less than illustrated here.

[0049] In the alternative second possible embodiment of a first deformation region 45 shown in FIG. 3, the mutually facing sides of the upper first deformation belt 46a and of the lower first deformation belt 46b do not run parallel to one another but are oblique relative to one another, or the spacing thereof decreases somewhat in the throughput direction from right to left, advantageously by 1% to 5% or even 15%. The clear pass height simply becomes smaller. Here too, the ridges 34a and 34b of the shaping dies 30a and 30b rest against the first deformation belts 46a and 46b. However, it can be seen very clearly how, on the right, the compound structure comprising the flat web material 12 and the holding dies 20a and 20b is still flat and level but, as it progresses increasingly through the first deformation region 45, is deformed because the shaping dies 30a and 30b engage in one another to a greater extent owing to the decreasing clear height and, in the process, deform said compound structure.

[0050] Here too, it is possible for the subsequent deformation region to be designed in the same way as the first deformation region 45 illustrated here in FIG. 3, i.e. for uniform deformation beginning virtually at zero. The combination of the deformation regions as shown in FIGS. 2 and 3 has not been depicted explicitly but is likewise conceivable.

[0051] In FIGS. 4 to 6, the intention is to illustrate, in three steps, how the deformation, ultimately of the flat web material 12 but also of the holding dies 20a and 20b, by the shaping dies 30a and 30b becomes more and more pronounced. In FIG. 4, no significant deformation of the flat web material 12 and of the holding dies 20a and 20b resting against said material is yet visible in the x direction, which is transverse to the throughput direction through the device 11. In the y direction in the throughput direction, however, an initial deformation is already clearly visible, so that the compound structure comprising the flat web material 12 and the holding dies 20a and 20b is slightly corrugated in this direction. In general, it is the case that a deformation in the y direction is always associated with a deformation in the x direction, but there may be significant differences of degree between them. As regards alignment, it is also conceivable that the x direction is along the throughput direction. For the sake of clarity, folding lines 14 and 14 of the flat web material 12 are already shown here, as are kink lines 22a and 22b of the holding dies 20a and 20b. The shaping dies 30a and 30b have ridges 34a and 34b projecting in opposite directions with correspondingly mutually facing depressions 36a and 36b. These are each formed by bending lines 32a and 32b. The depressions 36a and 36b in particular press by means of their relatively sharp edges corresponding to the ridges 34a and 34b into the compound structure comprising the flat web material 12 and the holding dies 20a and 20b. It can be seen here how the depressions 36a and 36b extend precisely along corresponding kink lines 22a and 22b of the holding dies 20.

[0052] More pronounced deformation of the flat web material 12 together with the holding dies 20a and 20b occurs in FIG. 5 through their being pressed together more, this now also being clearly visible in the x direction along the folding lines 14 and 14 of the flat web material 12 and along corresponding kink lines 22 of the holding dies 20a and 20b. In this case, the shaping dies 30a and 30b are still in contact with the depressions 36a and 36b linearly only along kink lines 22a and 22b of the holding dies 20a and 20b.

[0053] Even greater deformation is shown in FIG. 6. Here too, it should be noted that the compound structure comprising the flat web material 12 and the holding dies 20a and 20b has been deformed with the same intensity and to the same extent but the shaping dies 30a and 30b themselves have hardly been deformed at all. In this state, it would be possible in some circumstances for liftoff of the shaping dies 30a and 30b to take place already as in the first liftoff region 53 in FIG. 1. As an alternative, however, even greater deformation can take place. In the abovementioned case, the compound structure comprising the flat web material 12 and the holding dies 20a and 20b can only be deformed further through further shortening and also compression with the deformed flat web material 12 being raised in a more pronounced way.

[0054] Various possible embodiments of the shaped flat web material 12 are shown in FIGS. 7 to 13. On the extreme left, an isometric view is shown in each case, then a plan view from above, then a partial side view and, finally, on the extreme right, a plane folding pattern of, as it were, an individual cell. The embodiments in FIGS. 7 to 9 are characterized essentially by zigzag patterns of the folding lines 14, which in each case form ridges and depressions. There are therefore folding lines in two directions with angles of about 90 to one another in FIGS. 7 and 8 and 45 to 60 in FIG. 9. In FIGS. 10 and 11, these are patterns with a plurality of kinks along ridges and depressions at the folding lines 14, namely with a total of three instead of two directions. The angles are respectively about 135 in FIG. 10 and about 90 and 135 in FIG. 11. In FIG. 7 the angle is about 45 to 120 and the angle is about 15 to 90.

[0055] In FIG. 12, there are once again just two directions but these correspond instead to an embodiment corresponding to FIG. 10 with in each case a right angle at the individual kinks of the folding lines of the ridges and depressions.

[0056] In the embodiment according to FIG. 13, there is a special feature inasmuch as, here, the folding lines and thus also the ridges and depressions are not straight sections or segments but are curved or have a continuous corrugated profile, as mentioned at the outset. Here, the production of kink lines 22 in the holding dies 20 and bending lines 32 in the shaping dies 30 can be somewhat more involved but, in principle, this is also possible and conceivable.