MXPA99008657A - Method and apparatus for producing tubular hollow items - Google Patents

Abstract

In a method and an apparatus for producing tubular hollow items, in particular for containers, from card material or the like, to improve the efficiency and thus to reduce the costs in the production of known packages, the following steps are proposed:transporting a blank (22), bound by longitudinal edges, or a web (2) of card material or the like, from which the blank (22) is separated, into a bending station (5);the blank (22) or the web (2) being bent by guide elements acting as a bending apparatus and then being held stationary in the bending station (5) and being bent by means of movable bending apparatuses into the finished shape of the hollow item (15) and an overlap region being formed, in which the two longitudinal edges of the blank (22), which are parallel to the longitudinal axis of the hollow item, are placed one on top of the other and are connected to one another and the hollow item (15) being conveyed out of the bending station (5).

Description

METHOD AND APPARATUS FOR PRODUCING TUBULAR HOLLOW ARTICLES The present invention relates to a method and an apparatus for producing hollow tubular articles, in particular for containers, from a cardboard material or the like. Within the scope of the invention, the cardboard material is also understood to represent a flat board, "which is laminated on at least one side, preferably on both sides, on a plastic film. However, the invention also includes other flat or film-like materials, in particular single-layer plastic films or multiple layers or flexibly composite materials with an aluminum coating. The co-joins or is heat-sealed after the connecting regions of the template have been co-located on top of each other so that they overlap. When a pure cardboard material is used, an intermediate layer of plastic that can be welded in the form of a strip or a bond, for example, through a hot adhesive or the like, is used.

The methods and apparatuses of the above type are known especially for the production of packages for liquids. In this case, hollow tubular articles are produced from a cardboard material, subsequently closed at one end, filled and, in a final step, also closed at the other end. In DE-A 22 335 111, for example, a method and an apparatus for winding a multi-component band to form a hollow cylindrical article of cardboard material, according to said band, unrolled from a roll, is disclosed. it is partially inserted into a slotted sleeve where a tube is rotatably arranged as a mandrel and, together with the sleeve, forms a receiving space. Through a rotational movement, a section of the band is wound around the mandrel in the receiving space and subsequently transported out of the bending station. To increase the efficiency of the apparatus, four grooved sleeves, in cycles, are in use on a large wheel, as a result of which, however, the apparatus is mechanically complex and the construction sizes are considerably increased. In addition, a sleeve remains unused, which is seen in a revolution of the wheel, by virtue of the principle, which damages the degree of use of the system. The adaptation to transverse areas of the voids other than the rounds is not possible.In addition, described apparatus is used only to produce diaphragms, nor does it provide any connection of the hollow article in the overlapping region at the long edges. In addition, when using modern packaging materials or materials covered with cardboard, when observing the sliding friction, this device presents the risk of damaging the coating and also presents mechanical problems due to the size, of the construction of the apparatus based on the principle A method for the continuous production of tubular packaging articles from flat cardboard material templates is described in DE-28 50 882 Al. According to this method When, through a bending apparatus, a plant is flexed continuously to a hollow cylindrical article, the same as the after it forms a region of overlap of the edges of the template in the transport region. The transport region is provided with an adhesive and, when the hollow article is transported out of the flexure apparatus, it is compressed together and thus connected. Such a process based on gradual deformation requires a huge expense for transport apparatuses and a considerable construction size of the friction apparatus and thus also of the whole device. GB-A 2 124 140 describes a method for producing hollow articles in which templates are processed through mobile bending apparatuses, while being transported in a bending station. A forming mandrel defines the shape of the cross section of the hollow articles that will be produced. According to the description, the hollow articles have a rectangular cross section. This method always uses the transference of the cardboard template from a work station II to another work station III to bend a sealing tab preparing the final stage to connect the two longitudinal edges. After reaching the final position, the bending operation is completed by closing the hollow article around the mandrel. An ultrasonic sealing oven serves as a connecting means for sewing and sealing the connection area. This type of sealing does not protect the cutting edge of the laminated cardboard template that lies inward for a longer time against any type of moisture that occurs from an internal filling of the container during the time of use. There is a great requirement for packaging that is based on hollow tubular articles with a wide variety of cross-sectional areas such as a pre-product. The costs for the package now develop a significant portion of the cost of the packaged product. Here, it is precisely those stages of production made from the filling operation that make the package considerably more expensive. The object of the present invention therefore is to provide a method and a compact apparatus with an operation mode that is as simple and reliable as possible to improve the efficiency and thus reduce the costs in the production of known packets , which are used predominantly for liquids and / or long-life food products.

According to the invention, a method for producing tubular hollow articles having the following steps is proposed: - Transporting a template, joined through longitudinal edges, or band of cardboard material or the like, from which, the template is separated, towards a flex station; - the template or the band being flexed through guide elements that act as a flexing apparatus; - then it remains fixed in the station of f 1 e x i óñ; it is flexed through the mobile flexing apparatuses to the finished shape of the hollow article; "- a region of overlap is formed, wherein the two longitudinal edges of the template, which" are parallel to the longitudinal axis of the hollow article, are placed on top of the other; - they connect to each other; and - the hollow article is transported out of the flexion section. The object of the invention is also an apparatus according to the indication 28 which will preferably be applied to carry out the method according to the invention. The method according to the invention achieves the object stated above, since it advantageously combines a continuous bending process with a fixed bending process. In a first step of the method, the template or a band of cardboard material is continuously flexed through rigid guide elements when it is introduced to a bending station. When the band has been fixed, a defined section is produced, if the cardboard material is not used in the form of templates. In both cases, the p 1 a n t i TI a or section is already pre-flexed and remains fixed in the bending station for additional treatment. The movable bending apparatuses then take the final part of the configuration operation towards the finished form of the intended hollow article. In this case, an overlapping pattern is formed, where the two longitudinal edges of the template, running parallel to the longitudinal axis of the hollow article, are corked on the upper part of the other and are connected between each other. yes in a final step. The hollow article finally configured and closed through these production steps is then transported out of the station of faith. Since, in a method according to the invention or in an apparatus constructed for its use, the introduction of a template or a band is also used at the same time to pre-flex the cardboard material, the path of operation of the apparatuses Mobile bending is small compared to compression, bending arms and the like, such as those known, for example, in DE-A 25 12 852. Any reduction of a movement also reduces the wear of the bearings or guides, reduces it consumption of operating aids, such as, for example, oils and fats, and also reduces the energy requirement of said plant. Furthermore, an apparatus that operates according to the method according to the invention is distinguished by a small construction size, since, in particular due to the continuous and fixed confi rmation, the distances or the The radii of movement and the tsets of the parts that will be moved are minimized compared to those of the prior art. The individual stages of the method. they coincide with each other in an interactive way and can also be superimposed, so that short total cycle times can be achieved. A device according to the invention can therefore also be transferred to the filling machine to produce hollow tubular articles as a preliminary stage for the production of packaging articles. In this case, the cardboard material can be introduced into an apparatus according to the invention either in the form of templates or as an endless band. The carrier unit, which is superfluous when a template is used in the apparatus, can then work slowly or serve; to control the e_x dimensional attitude of the templates. This does not affect the extended function of the cutting unit, claimed in particular in the claim 11 with reference to the preceding sub-claims, during the cutting step, when it is supplied in the form of an endless band. or of a pr e-f apron template, the cardboard material is precisely placed at the same time in the plant and also advantageously already pre-flexed through guide elements.These guiding elements are configured in the form of rails and have a curved section, so that they flex the material at least partially circumvented around the mandrel.The guiding elements in this way can interact with the mandrel to guide and configure.To retain a predetermined precise position, the The template or band is preferably held tightly, preferably using a press, when it reaches a predetermined insertion length. The flexing station is maintained in a stationary manner and without additional transportation, as in other known bending and bending devices, it is bent or flexed around the mandrel at that site to form a tube of cross section respectively required. through mobile bending tools, in which case it is placed at least partially in the chuck. This procedure allows the efficient production of hollow tubular articles without the considerable requirement of space - and large ma in costs. The method according to the invention, therefore, can be easily disposed run above all known filling processes. The incorporation of the method of agreement Íl¬ The invention to the filling operation allows the rapid reaction and adaptation of the package according to requirements, such as, in particular, pack sizes in exchange and / or variations of equipment, such changes in the type of band or templates can The filling operation, due to the production of the package on the site, opens up new production possibilities oriented towards the requirement and efficient, in a preferred embodiment, the bending is carried out in the section. pre-flexionada, with the position fixed in the apparatus, through bending tools which are rotated around their own points of union in the bending station.After the stage of placing and cutting the band, the "Mobile bending tools in this way initiate the additional process of configuring the template. For this purpose, they are preferably coupled at least partially in a limb-type manner through the fixed elements of the bending section and, in the process, flex the assigned parts of the jig.

At the end of the bending opj_ ration, a region of overlap occurs through a compression unit in the region of the longitudinal edges. with the bending tools closed. This region is connected in the bending station by being compressed together and preferably welded or bonded, so that the aforesaid hollow or thus produced is fixed in a manner of welding by welding the posture of the hollow article. Precisely during the welding, it is advantageous if at least part of the mandrel is disposed below the "overlap region and the compression or welding unit in this way can serve as a counter-piece." For this purpose, according to With the claim 7, part of the mandrel is advantageously configured with a part of the anvil, between it and the compression unit at least a spot-type welding of the overlap region can be carried out. 8, this type of permanent fixing is carried out in durable, modern packaging materials, in particular by welding at least one plastic layer or a plastic coating present in the overlap region.

During the fixing operation, the mobile bending tools may already be open again since the connection region between the anvil part and the compression unit remains secure. The hollow article finally configured in this way is secured against undesirable deviations in the shape around the mandrel. By means of an additional operation, the compressor and moving the additional elements, such as, for example, an insertion aid, from that to its starting positions, a new section apart from a band can already be inserted in the - Bending apparatus below the hollow article that will be fixed or welded, that is, between the mandrel and the guide rails.Thus, in turn, two operations that are separate in terms of the process will be up-to-date In this way it is possible to save a lot of time and energy, see claims 9 and / or 10. In the refining of the method according to the invention, specific aspects for the packages must be taken into account. of packages for liquids coated with plastic, and in particular for packages with moisture content or very long life liquid, "it is necessary to protect at least one cutting edge of the template, located on the inside of the finished package, to the entry of moisture or liquid into the material "of the nucleus. For these particular conditions of use, a so-called bending or bending seam is preferably used in packages, mainly an additional longitudinal edge bent outwards in the region of overlap or connection. In the case of cardboard material coated with a plastic film on both sides, the longitudinal edge located on the inner side of the overlap region of the seam is folded towards the outside of the package and is covered by the longitudinal edge of the outer part of the package. In the arrangement of three layers thus formed, the plastic coatings of the individual layers always lie one on top of the other. These plastic layers can advantageously be connected to one another in a sealing manner, for example in a welding operation, without using additional adhesive or additional materials The known methods, which are compared for example with DE 35 31 663, to produce a fold seam, they are always constructed in several steps and finally provide not precise stitches, in this case, it is very common that the longitudinal edges of the folded seam will be displaced in relation to each other, so that the continuity in the design of the package can not be maintained.In contrast, according to the present invention, a bent seam is produced in an efficient and reliable way "with a precise position in the region of edge or in a central region. Based on the illustrative embodiments subsequently described, it can be seen that the method according to the invention can also be used for other packages and sewing patterns and sewing arrangements. According to claim 11, in the production of an article of a tubular hollow body with a bent seam, the material is pre-folded during the production of a template nail defined in the cutting operation in the region of the cutting edge thus produced In such a way that a first longitudinal edge is produced with an additional longitudinal edge pre-bent therein, this longitudinal edge is advantageously used, applying a simple elbow lever mechanism, to produce the longitudinal seam bent over the edge of the longitudinal edge. In accordance with claim 12, the additional longitudinal edge is simply formed by the fact that it is folded around a fold edge during the cutting operation through a top cutter. The additional longitudinal edge advantageously is determined in its width and shape of area through the transverse shape of the upper cutter. The configuration as the mandrel and the bending tools are adapted to their contact surfaces, where they are brought into contact at least partially with the template, for the desired final shape of the hollow article that will be produced. In this way, a complete correspondence is not required. For the method according to the invention and in the apparatus according to the invention, the band material or template with marking lines p r e-e s covered can be easily used. With the bending of the template around these marking lines, very precise bending edges or corners can be produced in a simple bending process. "As an alternative to this, in accordance with an additional development of the method according to the present invention and claim 23, the marking is printed on the cardboard material directly before the cutting operation. At the sites of these marking lines, the material is prepared in a precisely defined manner, so that the edges of the posterior hollow article are already formed in the "score lines merely due to the flexing of the band or the template in the fixed track elements of the bending station This bending or bending operation can furthermore be reinforced by the appropriate configuration of the profile of the mandrel, advantageously also together with the guide elements, accordingly, in a method according to the invention, not only hollow articles with a circular or oval section, but also those with triangular cross sections, square or straight lines, or other polygons can be produced efficiently and precisely. A compression unit is arranged in the bending station to act on the overlapping region of the configured template. According to the invention, its object is to compress together the longitudinal edges of the template, the limes are fed with precision one above the other or placed one on top of the other in the overlap region, in accordance with claims 15-17. Through a multi-part construction explained below with reference to the various illustrative embodiments "according to the apparatus claims 42-48, the compression unit ensures very accurate positioning of the longitudinal edges of the This advantageously ensures the exact position and precise configuration of the seam in the hollow article that will be produced.According to a further development, the compression unit is configured as a tool in relation to the mandrel. of combination in such a way that it can perform the prescribed placement and compression of the longitudinal edges and produce a seal weld "of the longitudinal edges in the overlap region. In addition, the compression unit comprises a welding tool, preferably in the form of a Sonotrode, which is used at the same time as a compression ram. In an apparatus according to the invention, in the case of a bent seam, the external fixation and a liquid-tight connection in the region of overlap in this manner are possible in a welding operation by welding the first longitudinal edge to a second, longitudinal edge of the template. The supply of material can be presented in an "apparatus according to the invention in a c-shape or in the form of templates or from a roll of a band of endless materials, already explained above. This can be done quickly by fixing a region of inserts over the bending station and programming the contrast in a different way. In a particularly advantageous further development, the endless belt is removed from a store, for the production of the which is folded into a concertina-like shape With the "concertina or fan-type fold, a rectangular external shape advantageously results, for example, for a wrapper as external protection and a conveyor and storage container for the web material . By using "ordinary" transportation devices, such as elevating cranes, etc., said wrappers can be transported and also stored more easily, in particular-on pallets, than the roll material. In addition, with a fan fold, the external surfaces and internal surfaces of the package are always in contact with each other respectively. For a hygienically satisfactory package, any transfer of dirt, for example, from an external surface to an internal surface, is thus regulated. The simple and rapid removal or dragging of the web material bent in this manner results, for example, from the fact that the wrapper opens on the upper side parallel to the bent strip portions located below it. The band can then be continuously pulled out of the wrapper without hindering in the direction of its longitudinal axis and feeding into the bending station. However, an important factor in the storage or provision provided with the web material in a fan fold is the fact that, according to claim 25, the web material is provided with a perforation in each case at the edge of the web. fold the fan fold. During the production of the web material, this region in folds can alternatively be provided with a smi-c. O Through this particular measurement it can easily be integrated into the production process, the storage volume of the external packages can be greatly increased by the higher stacking density of the material, since the region in folds located in each case at the outer edges in this way does not curve in relation to the central regions of the fold that lies in a stack. The web material is advantageously fed to the cutting operation directly through a wrapper. This is very simple and saves space compared to the known methods for loading apparatus for the production of pre-products or hollow packaging items. In a further development according to claim 26, the bend of the band is pulled in portions corresponding to the length of a template or a multiple of said length. In this fixed dimension pre-rolled by the type of packaging ", compact stacks are formed in a fold, the region" in folds is no longer noticeable in the finished package or the welded hollow article. A plurality of bands advantageously are arranged adjacently, for example in stacks, in the store or wrapper. In particular, in this arrangement, a plurality of bands can also be simultaneously removed in parallel from the wrapping. The applicant reserves the right to establish independent claims for the individual units of the apparatus, wherein the steps of the method described are in each case imp1emed technically in an innovative manner. It is e violent from the foregoing description of its respective function that the advantages emerge not only in the interaction of the units in an apparatus according to the invention. Otherwise, the units can also be used advantageously in other machines, for example, as a replacement for specific elements of a plant according to the prior art. The content of claims 2-48 is incorporated herein by reference without repeating the claims. The illustrative embodiments of the invention are explained in more detail with reference to the drawings, in which: Figure 1 shows "a side view of the construction of the principle of an apparatus for producing tubular packages in a first embodiment; Figure 2 shows a side view of the apparatus of Figure 1 with impellers, partially n an operating position that is different from that in Figure 1; Figure 3 shows a front view in relation to Figures 1 and 2; Figure 4 shows a plan view of a part of the apparatus of Figures 1 and 2; Figure 5 shows a perspective illustration of the apparatus of Figures 1 and 2; Figures 6a-61 show a diagrammatic illustration of the sequence of the apparatus of Figure 1 in individual steps; Figure 7 shows a simplified illustration of a filling machine whose first part "comprises an apparatus for producing tubular packages;" Figure 8 shows a diagrammatic illustration of individual steps of the processing of the web material; Figures 9a, 9b show perspective illustrations. of wrappers for the storage and use of cardboard material; Figure 10 shows a simplified side view of an apparatus for producing a simple longitudinal seam which is not bent; Figure 11 shows a detail of Figure 10; Figure 12 shows a perspective illustration of a part of a compression tool of Figure 11; and Figures 13a-13g show a diagrammatic illustration of the sequence in an alternative apparatus for carrying out the method. Figure 1 illustrates a first embodiment of an apparatus 1 according to the invention in a side view. In the illustrated apparatus 1, hollow articles with a square cross section are produced, wherein the seam is bent and the sewing point lies along an edge of the hollow article as will be explained below. In the step of the illustrated method, a strip 2 of a cardboard material which is coated with PE on both sides is inserted into a bending station 5 through a tracer unit 3 by a cutting unit 4. The conveyor unit 3 It is configured as a roller or roller drive and comprises a free-running and spring-loaded nozzle roller 6 above the web 2 and a drive roller 7 below the web 2. The control of the u? ~ i conveyor 3 will be described later. The band 2 runs through the cutting unit 4, comprising an upper cutter 8 and a lower cutter 9, in an open state. In the position illustrated in Figure 1, a comb-like bend edge 10 is located opposite the upper cutter 8 at about the same level as the lower cutter 9. During the cutting operation, the bending comb 10 can be understood to be a constituent part of the cutting unit 4 which represents its function which will be described in detail in the description of the operation during cutting. The band 2 is inserted into the bending station 5 below an insertion aid 11. The bending station 5 comprises fixed and movable parts. In the illustrated process step, the band 2 behind the insertion aid 11 is only in contact with the immobile parts, in this way it is transported further on the guide rails 13 with the aid of the insertion aid. 11 between a mandrel 12 and the guide rails 13 and, in the process, is bent upwards through a "curve" section of the guide rails 13 and is thus already pre-bent. I Dial lines 14 (not shown) have been previously printed on the web 2. In these dial lines 14, the web 2 is folded into a curved section of the guide rails 13, and the last edges of a tubular hollow article 15 that will be produced are already formed here. Without the marking lines 14, hollow articles 15 with a circular or elliptical cross section can also be produced with or even without a bent seam through the adaptation of the apparatus 1. Mounted below the guide rails 13 there are two bending tools 16, 17, which are pivotable on axes 18, 19. The tubular hollow article 15 is closed by the bending tools 16, 17 after the cutting operation and kept closed until a compression unit 20, disposed at the upper end of the guide rails 13, terminates the bending operation and produces the seam on the hollow article 15.

Also arranged below the guide rails 13 of the bending station 5 is a compressor 21, which fixes a template in its press, "said template is obtained during and after the cutting of the band 2. Consequently, the cut of the web 2 is associated with the production of an additional pre-folded longitudinal edge.The final product produced in the apparatus 1 is then the tubular hollow article 15, which is open on both end faces and is discharged from the mandrel 12 through of a slide 23 illustrated by dotted lines in Figure 1. Figure 2 shows the side view of Figure 1, representing additional elements of the apparatus 1. For example, it can be seen in Figure 2 that the rail 2 is guided on a table 24 with guides 25 towards the conveyor unit 3 upwards of the cutting unit 4. In addition, the impellers necessary to operate the apparatus 1 of this embodiment are indicated in Figure 2. The roller 7 is driven by an engine Al, and the cutting unit 4 is driven by a pneumatic drive A2. Through a lever control, an additional pneumatic drive A3 activates essential parts of the bending station 5, mainly the insertion aid 11 and the bending tools 16 and 17. The cutting unit 4 can be operated in one cycle in conjunction with the compressor 21. Here, however, the compressor 21 is provided with its own drive A4. An impeller A5 of the compression unit 20 and an impeller A6 of the slide 23 are only indicated. Figure 3 illustrates a front view of the apparatus 1 in the manner illustrated in Figure 2. For reasons of clarity, some of the aforementioned impellers and parts have not been illustrated or have been cut. Figure 3 has been partially cut to give an at least partial illustration of the lever connections In the illustration of Figure 3, the maximum width "of the band 2 to be processed is specified. Indirectly, the height of the hollow articles or packaging pre-products is prescribed. To adapt, for example, to liquid packages with a smaller volume, the width of the table 24 can be adjusted by moving the lateral guide 25 (not shown here in detail). Figure 4 illustrates the apparatus 1 of Figure 2 in a plan view, driving elements again being cut or omitted for reasons of clarity. Table 24 with the guides 25 can be seen in Figure 5. Indicated on a non-adjustable lateral guide 25a of table 24 is a measuring cell 26, which controls the impeller Al in the conveyor unit 3 through scanning optical reading markers made on the band 2. In addition, the layout and the course of the individual parts of the "flex station 5 can be seen referring to Figure 4. In this way, for example, the guide of the inserted band 2 by individual guide rails 13, is illustrated.In addition, the end-type construction of the section tool 17 is illustrated, wherein the bending tool 17 in the form of "individual levers can be inserted between the guide rails 13 for flexing the web _2 through the rotation about the axis 19. Encesta view in plan, the transition region of the table 24 to the conveyor unit 3 and the cutting unit 4 also "is lustra From the cutting unit 4, the band 2 is fed to the bending station 5 between the insertion aid 11 and the adjacent ends of the guide rails 13.

Figure 5 is a perspective illustration of the apparatus 1 of Figures 2 to 4. The measurement cell 26 is illustrated in the region of the fixed side guide 25a on the board 24. This illustration shows the compact construction of the apparatus 1 with the conveyor unit 3, cutting unit 4 with a folding comb 10, insertion aid 16, bending station 5 and compression unit 20 arranged above the bending station 5. The mandrel 12 as part of the station of flexure 5 has a guide rail 27 for the slide 23, illustrated with its impeller A6, of a sliding unit 28 and, on the other hand, for an anvil-30. The anvil 30 serves as a counter-piece for the combination tool of the compression unit 20, which will be "described later with reference to the figures of various modalities." With reference to a sequence of figures based on the construction of the Apparatus of Figure 1, the method of operation and functional sequence of the apparatus during a complete cycle is illustrated in the following: Figure 6a shows the band 2, which is in s to a predetermined length in the bending station. between the insertion aid 11 and the guide rails 13 above the mandrel 12. In this situation, the measurement cell 26 (not shown here) detects a reading marker on the underside of the band 2 and stops the unit conveyor 3. Figure 6b illustrates the next step in the process where the unit ^ cutter 4 is closed.In this case, a piece precisely determined and separated from the band 2 and then processed to Typically as a template 22 e the station of f 1 e "x ion 5. For a precise adhesion of the dimensions of the template a-22, the band 2 is fixed directly before the cutting operation by the compressor 21 as it is held from below against the mandrel 12 by the compressor .21 between the guide rails 13. During the cutting operation, the strip is separated between an upper cutter 8 and a lower cutter 9, the template 22 thus produced is pre-arranged. bent always with the same dimensions by the upper cutter 8 in a fold edge 10. In Figure 6c, the "template 22, which is fixed in place through the compressor 21, is further made in the form of the tubular hollow article that will be produced by the bending tools 16 and 17. In doing so, the jig 22 is flexed or bent around the mandrel 12 in the bending station 5, the edges of the side walls of the final hollow article are formed by in the points of the lines of dialing 14. During this operation, the insertion aid 11 is not used and, therefore, is moved to a rest position. In which case, at the same time, the space required for the movement of the bending tool 16 is released. In this case, the joint or shaft 18 of the bending tool 16 is deflected with. relationship to the dial line 14a, around which the back part of the "insole 2" 2 is flexed, so that, when the bending tool 16 is placed against the mandrel 12, the region The pre-bent form of the template 22 is securely supported with its cutting edge against the bending comb 10, without sticking out.Figure 6d shows the apparatus 1 in the almost completely closed state.The bending tools 16 and 17 are illustrated in FIG. its extreme position, the template already flexed to the extent that the shape "destined for the hollow article has almost been reached. The compression unit 20 is lowered from above on a region of the mandrel 12 configured as an anvil 30. Here, it is important to arrange the pre-bent region of the first longitudinal edge down the second longitudinal edge. For this purpose, the compression unit 20 is of a two-part construction. As the first part, a comb part 31 is lowered over the region already pre-bent. In this case, the comb part 31 engages in depressions in the bending comb 10 which is attached to the end of the bending tool 16., thus preventing the longitudinal edge from being trapped during the described closing movement. The comb part 31 is attached in a "spring" to a welding tool 32, advantageously designed as a Sonotrode.These two parts in this manner can be moved together as the compression unit 20 through the impeller A5 (not shown). here). "Figure 6e shows the bending operation • and fold with the reduction of the fixing unit in its final phase, wherein the rear overlapping region 29 acts in the form of a simple elbow lever mechanism Here, the bending comb 10 and the "comb part 31 coincide with each other and compress the first edge. longitudinally 33 with the pre-bend inward, so that, through the second longitudinal edge 35 which is bent on the welding tool 32, as a result of a bent corner seam is formed "between the welding tool 32 and the Anvil portion 30 of the handle 12, said corner seam is made of the first longitudinal edge 33, an additional longitudinal edge 34 and a second longitudinal edge 35. With the transition to Figure 6f, the bending and bending operation is it ends by the complete descent of the compression unit 20. In the overlapping region 29"of three-layer construction, a bent longitudinal seam is welded in the single-stage method illustrated. At the same time, the cutting unit 4 is again opened up n_d or the upper cutter 8, and the compressor 21 is lowered to release the clamping on the mandrel 12. In Figure 6g, the welding of the longitudinal seam 36 between the welding tool 32 and the anvil portion 30 is continuous, while the bending tools 16 and 17 also remain opposite again and the insertion aid 11 moves back towards the position of Figure 6a. In the position of Figure 6f or 6g, it is possible in a very simple way to integrate a bad sheet selection as an alternative process step in the apparatus. Therefore, if an optical input control has discovered an erroneous template 22 or an erroneous region of the web 2, the bending tool 16 can be maintained in the illustrated position. With the proper configuration of the lower edge of the bending tool 16, the part of the band 2 or the p 1 atelier 22 introduced into the apparatus in this manner can be flexed, for example, driven out of the apparatus 1 in the background. This erroneous region in this way can not enter the bending station "5 for nothing." After the cutting operation, the apparatus 1 again becomes available as described above.

Figure ^ dh, and the bending tools 16 and 17 as well as the insertion aid 11 have again reached their starting positions. In this case, the welding operation on the folded longitudinal seam 36 is continued.

The apparatus 1 is thus prepared to receive an additional section of the belt 2 and, as illustrated in Figure 61, a new section of the belt 2 in this way can be introduced through the conveyor unit 13 by the unit cut 4 through a passageway 37 between the hollow article 15 which follows in the welding process and the guide rails 13. Figure 6k illustrates how the band 2 is introduced in the flexure unit 5, while the sole "Dart or sealing of the longitudinal seam 36 of the hollow article 15 continues to occur, and is already pre-bent - In the process step illustrated in Figure 61, the welding of the longitudinal seam 36 on the hollow article Í5 has been completed At the same time, the placement and measurement of the correct length of the newly introduced section of the band 2 have also been completed.The compression unit 20 is thus raised again, as a result of which the hollow article 15 now complete on the mandrel 12 can be moved freely by the slider 15, i 1 usted by dotted lines, and transported out of the apparatus 1. The cycle is thus completed, and the "method starts again with the stage of the process illustrated in Figure 6a. It is evident from the entire sequence of Figures 6a to 61 that the moved parts of the apparatus 1 have to travel - short distances. This is achieved, above all, due to the fact that the band 2 is already pre-flexed by the round sections of the guide rails 13 when it is inserted in the bending station 5 and in this way is maintained at a low level compared to the plane of the longitudinal costum 36 and is already flexed and fed to this final position. Figure 7 shows a complete machine for lining and packing liquid media during the operation. The first part of the illustrated plant comprises two apparatuses operating in parallel, as described above. The apparatuses are illustrated in a simplified form in the drawing, the strip 2 is introduced into the apparatuses in each case from a magazine 38, cut to size, cut and welded. , "s or" ñ transported in an intermediate step Z to the right towards the actual filling plant, the plant "of full of two lanes being eating available in this way and only requires a slight adaptation to the new apparatus 1. Each apparatus 1 in this way feeds a lane of the filling machine. However, apparatus 1 operates - in principle, faster than the filling machine. The operations within the same plant of the 11th year are known in principle and do not require a description here.The extra costs for the illustrated expansion of the filling machine are only compensated after a short period of operation through the reduction of costs for packaging materials _ Figure 8 shows a diagramatic illustration of the sequence of the apparatus method l - the transfer of the finished hollow articles towards the known filling device, here the band 2, already illustrated in Figure 7 is a return to a warehouse 38. "In this case, the warehouse 38 is" a wrapper 39 in "" where the strip 12 is arranged as a stack "40 with a fan fold or with a fold, concertina type. The band .. 2 is produced by a packaging material manufacturer with a perforation 2b in the fold region 2a of this fold and is placed in the fan folder in the wrapper 39. Through this perforation 2b, the "which it can also be replaced by a semi-cut, the fold region in the finished fan fold can be bent to be well below the central fold region.Thus, any curved shape of the folded fold regions 2a in the wrapper 39 is reduced to the minimum in favor of a storage capacity .. even greater with the same external dimensions.In this case, the wrapper 39 serves at the same time as a transport and storage container. When finishing the web 2, the marking lines 14 can already be printed on the web 2 by the packaging material manufacturer. However, if the webs are advanced "towards the operator of the machine to 1 and to the filling machine connected in an unprocessed state in this respect, the marking lines 14 and other markings, for example, the so-called separation tabs, can be made in the band 2 in the "marked" by B in Figure 8. The band 2 runs through the conveyor unit 3 to the cutting unit 4. As templates 22, these are bent in stages to become hollow tubular articles 15 and welded and transported through a intermediate transit Z to the filling machine. In the illustrated form, the long-term loading of the apparatus 1 is possible without difficulty. During operation, this additionally costs the personnel costs. In addition, a quick and simple design exchange can be made, and still others can be done.When the apparatus 1 is defined, the band 2 is "formed" of the conveyor unit 3 and is inserted into a new band 2. placement of the new band 2 is automatically presented through the "conveyor unit 3 coupled to the measuring cell 26, so that, due to the precise adherence to the dimensions of the template, then the first piece without waste related to the system is produced, Figures 9a and 9b present, in a perspective view, shows possible shapes of packaging and storage of wrappers 39 for bands 2 bent by fan for a different package size With the adaptation of ime ns "on transport systems that are common in Europe and around the world, approximately 2500 templates are stored in a wrapper 39 in each case in two stacks 40 arranged adjacently in parallel. The type of web storage continuously increases the utilization of space compared to previously known storage methods for tubular hollow items 15. According to a previously common method around only 600 hollow items 15 can be stored in In the known systems, on the one hand, the volume of use in the wrapping machines is much less efficient and, on the other hand, operation personnel are required to load the filling machines, which means that the weight of the Wrappers are completely limited by occupational safety regulations to less than 10 kg. "That, in the method described, no heavy physical work by the operating personnel is necessary to reload individual hollow articles. or the templates 22 or here predominantly the bands 2, the weight restriction for the wrappers 39, passed for safety reasons of tra low, it does not matter The pack sizes of the wrappers 39 in this manner can be freely adapted to the usual standard dimensions in transpor ture systems, resulting in a less problematic total storage and more efficient transportation. The illustrated ventilation consists of the fact that in each case only the external printed surfaces or internal surfaces directed towards the side of the final product are in contact with each other, in this way, the dirt on the internal surfaces can be regulated. 9a shows four wrappers 39 arranged on a pallet 41, so that on this pallet 41 only, the strips 2 for approximately 20,000"hollow items can be" stored, transported and placed in front of, or at the bottom of the apparatus. 1. In this example, the hollow items that will be produced have a capacity of 1 liter of liquid. 9b shows, similar to Figure 9a, the bands 2 in stacks 40 folded by fan for "hollow items that. They have a filling volume of 0.5 liters in a filling machine. In one of the illustrated envelopes 39, two stacks 40, together comprising 5000 templates, are arranged in parallel and can be removed at the same time, so that a total of 30,000 templates in the form of band 2 is available on the pallet 41. The method described can be varied within wide ranges and can be adapted to different production conditions and transverse shapes of hollow articles Hollow articles 15 with a round or oval cross section in this way can be produced analogously by adapting the mandrel 12 and the bending tools 16 and 17 without marking lines 14 which have to be pre-printed on the web 2 or the stencils 22. By making slight changes, the hollow articles 15 with a rectangular cross-section can also be produced using the a ^ pratorate illustrated in FIGS. 6a to 61. One embodiment of the method according to the invention has been described before From the point of view of the bent corner posture that is going to be preferred and is slightly more complex in terms of production. For reasons of continuity of the package design, the bent corner seam is currently preferred. Folding over the seam in the construction by inserting an additional longitudinal edge 34 onto the first longitudinal edge 33 and the overlapping cover along the second longitudinal edge 35, a seam is provided which is permanently strong and resistant to liquid from the bottom, and is used, in particular, in food products with a long storage life. Here, the packing material of the band 2 is coated with a PE film on both sides and furthermore has a closed aluminum lamination in order to prevent light and oxygen from entering the interior of the package. "In the sector of packaged food products with a relatively short storage life, less complex cardboard materials are used with simpler welded seams." Figure 10 shows an embodiment of the apparatus 1 for producing a corner seam, which is bent in the production of hollow tubular articles 15. In contrast to this, the apparatus of Figure 10 comprises a simplified design of a cutting unit 4a since, with the band 2 cut to form a template 22a, no pre-bending of an additional longitudinal edge 34 is necessary. The process step illustrated in Figure 10 corresponds to that of Figure 6e of FIG. first modality. Regarding the lack of an additional longitudinal edge 34 in Figure 10, the construction of the folding comb 10a has been changed in the manner illustrated in order to bend the first longitudinal edge 33 over the region around the anvil 30c of the mandrel 12 Figure 11 illustrates a detail of Figure 10. Here, the region around the anvil 30 and the end of the welding tool 32 with the longitudinal edges 33 and 35 guided or maintained therebetween, is illustrated on an enlarged scale. It can be seen that, when the bending tool 16 is closed and the trailing edge of the template 22a is compressed against the anvil region 30 of the mandrel 12, the first longitudinal edge 33 is flexed to 1"of the region. of anvil 30 about a marking line 14 through an additional bending edge 10b on the modified bending comb 10a The first longitudinal edge 33 in this way lies below the second longitudinal edge 35 before the final descent of the compression unit 20, and the outer and inner plastic liners 42 and 43 can be compressed on the top side of the other and welded through the welding tool 32 on the anvil 30.

Figure 12 shows the position of the F i g u r a_ 11 in a three-dimensional illustration. The bending tool 16 is completely closed, so that the folding handle 10a bears against the mandrel 12, and the first longitudinal edge 13 is flexed around the anvil 30 through the edge 10b. Furthermore, it can be seen here how the comb part 31 of the compression unit 20 engages in the slots or comb structure of the fold comb 10a. Through the comb structure, preferably in each embodiment of the present invention, neither the first longitudinal edge 33 nor the second lateral edge 1 nor the longitudinal edge 34 (not present in the illustrative embodiment) is secured. of Figures 10 to 12) can be trapped and thus destroyed between the folding comb 10 or 10 and the compression unit 20 when the compression unit 20 is lowered, Figure 13a shows a further embodiment of a Here, a bent seam is produced in a central region of a hollow tubular article 15 from templates 22c separated from a band 2. In so doing, the alternative embodiments of a cutting mode 4c, the tools of flexure 16c, 17c and the compression unit 20c are configured as illustrated in Fig. 13a In the sequence of Figs 13a to 13g, the sequence of the method is illustrated below similar to Figs. a to 61. In terms of the process step, Figure 13a corresponds to Figure 6a. Here, the band 2 is inserted by the conveyor unit 3 towards a flex station 5c and is pre-bent. However, at the anterior end of the band 2a, in contrast to the first embodiment of Figure 6a, an additional longitudinal edge 34c is already punctured. Figure 13b is a momentary image of the cutting operation in which the template 22c, thus placed in the flexure apparatus 5c and hermetically clamped against the mandrel 12c by the press 21, is separated from the band 2. through the cutting unit 4c Figure 13c - shows the conveyor unit 3 together with the cutting unit 4c in an enlarged illustration From this figure, it can be seen that the cutting unit has been modified compared to the first embodiment of Such a way that a fold edge 10c is disposed in each case on the first longitudinal edge of a jig For the transport of the additional longitudinal edge 34c beyond the bottom cutter 9, it is possible either to raise the longitudinal edge 34c towards r_i ba or move the lower cutter Lo r 9. The illustration of Figure 13d corresponds to that of Figure 6e in the first mode and illustrates the bending station almost completely closed 5c with a tubular hollow article 15c, formed from the template 22c, contained in 1 to my sma. - In an enlarged illustration of the understanding unit 20c of Figure 13d, the bending and bending sequence directly before the compression unit 20c is closed as illustrated in Figure 13e. The additional longitudinal edge 34c is moved, in the pre-bend form, by the guide rails 13 below a comb part 31c of the compression unit 20c, "in such a way that it is placed- in its pre-folded state. below the as per d_p longitudinal edge 35. The comb part 31c performs this function since __i immediately engages in an anterior shape with the additional longitudinal edge 34c in the region of the ends of the guide rails 13. The comb part 31c in this arranged manner is disconnected from the welding tool of the compression unit 20c on a support 44 in order to be able to descend downwards.When the bending apparatus 5c is closed, the second longitudinal edge 35 hits the its cutting edge against the comb part 31c and is driven downwards by the welding tool 32. In the process, the second longitudinal edge 35 is accurately positioned.The force for compressing the comb part 31c is washer by the welding tool 32 on the comb part 31c by the fact thatwhen it is lowered to a part 45 of the comb part 31c, it is compressed against a restoration spring 46 and thus compresses the comb part 31c down towards the jig 22c. In Figure 13f, the apparatus is illustrated with the flexure apparatus 5c completely closed and the compression unit 20c down. The hollow article 15c with the folded central seam is closed around the mandrel 12c, and the longitudinal seam 36c can be welded in the process step i lustrated.

Figure 13g shows a detail of Figure 13f with the region around the longitudinal seam 36c disposed in the central region. Here, it is evident how the "comb part 31c descending opposite the welding tool 32 serves as a stop for the second longitudinal edge 35 and thus guides the latter toward a precisely predetermined position. In addition, the comb part 31c keeps the anterior part of the template 14c compressed on the mandrel 12c, so that when lowering the welding tool 32, the first edge 1 ongi your dinal 33c is placed with the additional folded longitudinal edge 34c below the second or longitudinal edge 35, and this construction can be welded after it has been compressed together With the apparatus described, exchanging the cutting unit 4c with the cutting unit 4a of Figure 10 and connecting the part of comb 31c to welding tool 32 in a manner similar to the manner illustrated in Figure 1, a hollow article can also be produced, which has a simple seam that is not bent in its central region.

Claims (41)

1. A method for producing hollow tubular articles, in particular for containers, from a cardboard material or the like, having the purposes of: - transporting a template, joined through longitudinal edges, or a band of cardboard material 'or similar, starting __d e where the template is separ ard a, towards a bending station, the template or the band can be folded through guiding elements acting as an apparatus of f 1 exi or "ny, - after they are fi xed in the station of f 1 exi o "ny - they can be bent through mobile bending apparatuses to the finished form of the hollow article and a region of overlap that is formed where the two longitudinal edges of the template which are parallel-to the longitudinal axis of the hollow article, are placed on the upper part of the other, wherein - an additional longitudinal edge, especially a pre-bent edge, between the first and second longitudinal edges is compressed. jointly, in combination with the latter, to form a three-layer construction, and - the aforementioned parts are connected together and I the hollow article to be transported from the bending station.

2. The method according to the claim 1, characterized in that: while being transported towards the station, the jig or band is put in coupling with, with rail-type guide elements, in particular, fixed ones which have a curved section, the jig or the band is configured therefore in the curved section and is flexed, in particular at least partially, around a mandrel, the band or the template is guided towards the bending station between the guide elements and the mandrel 1.

3. The method according to one or more of the preceding claims, characterized in that: the jig is placed at least partially against the mandrel and - subsequently it is bent to a finishing state to connect the longitudinal edges through bending tools - which are rotated about their propicr point of union while the template is held in a predetermined position by a compressor.

4. The method according to claim 3, characterized in that - while the bending tools are closed, the two longitudinal edges lying parallel to the longitudinal axis of the hollow article are placed on the upper part of the other and they compress each other through a compression unit.

5. The method according to one or more of the preceding claims, characterized in that the end slape of the longitudinal edges of the plant is placed against the mandrel to produce the connection re gion.

6. The method according to one or more of the preceding claims, characterized in that the overlap of the longitudinal edges is maintained between an anvil portion of the mandrel and the compression unit and is set to produce the overlap region, preferably through at least one point type welding.

7. The method according to one of the preceding claims, characterized in that the overlap region is welded in a sealing form, in particular by welding at least one plastic layer or plastic coating present in the overlap region.

8. The method according to claim 6 or 7, "wherein accrued - the overlapping region that is being fixed, is possibly welded, the bending tools are opened again.

9. The method according to one or more of claims 6-8, characterized in that - while the overlap region is fixed, possibly welded, with the opening of the tools of f 1 exi or "h - a compressor is also opened and an insertion aid, if it was moved to a different position for the bending operation, it is moved back to its reading place upstream of the fl "x ion station, - an additional section of the band or a template being introduced into the station. f 1 exi ó ~ hy - the previous template is arranged below.

10. The method according to one or more of the preceding claims, characterized in that: - when a given insertion length has been reached, the template or the band is held in a position predetermined by the compressor in the station region of bending, when a predetermined insertion length of the band has been reached, the plant iL is separated from the band and, - during the cutting operation, the band 2 and / or the template is pre-bent in the edge region cutting, preferably parallel and with a space defined from the cutting edge.

11. The method according to claim 10, characterized in that the web is separated between an upper cutter and a lower cutter and - the pre-bend is introduced through the interaction of the cutter. a fold edge which is located opposite to the upper Rc counter.

12. The method according to claim 10 or 11, characterized in that the length of the insoles and the width of the pre-bend can be adjusted.

13. The method according to claims 10-12, characterized in that, before the cutting operation, the band is marked in the cutting edge region, or the template is marked for the pre-bending.

14. The method according to one or more of the preceding claims, characterized in that a first longitudinal edge is bent around the mandrel through a part of the compression unit, which is constructed in the form of a comb part.

15. The method according to claim 14, characterized in that a second longitudinal edge is bent by lowering the compression unit in such a way that the second longitudinal edge engages the first edge 1 or n g i t i d i n a 1.

16. The method according to claim 15, characterized in that the second longitudinal edge covers the first longitudinal edge in such a way that the second longitudinal edge extends over the additional longitudinal edge in the three-layer construction and is joined through the part "of extension to the first longitudinal edge.

17. The method according to one of the preceding definitions, characterized in that the marking lines are only produced before the band or the template enters the flexure phase.

18. The method according to one or more of the preceding claims, characterized in that - it produces a hollow article without any bending edge, for example, with a circular cross-sectional area, - an additional longitudinal edge of the first longitudinal edge of the template in the bending station "- bends during the cutting operation - along a marking line towards the outside of the hollow article Y - overlaps in uTTa region by the second longitudinal edge.

19. The method according to one of the preceding claims, characterized in that the band is guided to the cutting operation from a storage, for the production of which it doubles in a concertina-like form, for example, out of a wrapping, each bending edge "" or fold region of the band material in the fan fold being provided with a perforation or a half-cut.

20. A method according to claim 19, characterized in that the fold of the band is pulled in portions corresponding to the length of a template or a multiple of said length.

21. The method according to claim 19 or -20, characterized in that a plurality of bands are arranged adjacent in the storage or in the wrapper and are removed, in particular simultaneously in parallel.

22. An apparatus for producing hollow tubular articles, in particular for containers made from cardboard material or the like, having a conveyor unit for transporting and placing a band or a template, a cutting unit for separating defined templates from the "web" in the case that the material is supplied in the form of a band, - a bending station for pre-f lexi ona a template or the band during insertion and "" "- in addition the fold station folds the template, which is fixed in place, around a mandrel to form a the tubular hollow article terminated with open end faces, a compressor is disposed on the boss located in such a way that the jig is raised and, if appropriate, compressed by a third side against the mandrel to "fix it / in place", so that the passage for inserting the next template is formed below the mandrel and "- a compression unit for connecting in a region of overlap of the welded insole, a sliding unit for further transport of the finally formed hollow article.

23. The apparatus according to claim 22, characterized in that the conveyor unit for transporting the band or the plant comprises a roller or roller impeller, in particular as a combination. ation of a spring-loaded clamping roller and a drive roller, between which the belt or plant will run. ^ ~

24. The apparatus according to claims 22-23, characterized in that an insertion aid can be moved between a reading position and at least one position outside the insertion point, in particular it can be pivoted on a circular path between said positions. positions.

25. The apparatus according to one of claims 22-24, wherein the bending station comprises fixed guide elements which act as a bending apparatus, have at least one curved section and preferably they are configured as guide rails, "arranged separately apart in parallel from each other, to pr - fx the band or a template while it is being inserted.

26. The apparatus according to one of the rei indications 22-25, characterized in that a configuration body or a mandrel is engaged in the bending station, against which the template is placed, flexing "and bending at least in sections a through bending tools and achieves the shape of a hollow article.

27. The apparatus according to claim 26, characterized in that the cross-sectional profile of the mandrel lies within the cross-section of the hollow body that will be produced, and the generation lines of the cross-section are left in place. contact in the places where the template is placed against the mandr i 1.

28. The apparatus according to one of claims 22-27, characterized in that the bending station comprises at least one first movable bending tool, which realizes the bending of the front section of the template and folds a first side of the template and moves it to a predetermined position relative to the mandrel and, if appropriate, places the first side against the mandrel.

29. The apparatus according to one of claims 22-28, characterized in that the bending tool is of a limb-type configuration and, for bending and / or bending, engages the gaps between the adjacent guide rails.

The apparatus according to one of claims 22-29, characterized in that the bending station comprises at least one second mobile bending tool, which is located opposite the first tool and flexes a second side of the template , located opposite the first side, in a predetermined form.

31. The apparatus according to one of claims 22-30, characterized in that - the cutting unit comprises a fixed lower cutter and a movable upper cutter, - a part of the apparatus being located with a bending edge, - opposite to the upper cutter. to produce an additional longitudinal edge and - the lower cutter and the edge of the fold receiving the upper cutter between them at the end of the cutting operation.

32. The apparatus according to claim 31, characterized in that the width of 1 additional longitudinal edge, pre-folded, - essentially corresponds to the width of the transverse area of the upper coater located perpendicular to the cutting direction and 'above the "Cutting surface and can be adjusted, - in particular, through these means.

33. The apparatus according to one of claims 31-32, characterized in that the bending edge is disposed on the second bending tool, which moves between the position on the bending unit and the bending positions or flexion.

34. The apparatus according to one of claims 30 to 33, characterized in that the second fl exing tool has an inclining bend edge for pre-bending the first longitudinal edge on the mandrel.

35. The apparatus according to one or more of claims 30 to 34, characterized in that the second wave tool is assigned to a bending principle that places the first longitudinal edge against the mandrel in the closeness of the edge of the mandrel, the fold element preferably "being a constituted part of the compression unit.

36. The apparatus according to claim 35, characterized in that the bending element is configured as a bending comb and, when the first longitudinal edge is placed against the mandrel, it is guided in corresponding grooves in the second tool. f 1 exióñ.

37. The apparatus according to one or more of the embodiments 26 to 36, characterized in that the compression unit comprises a compression ram which, in order to place the first longitudinal edge against the mandrel, and is lowered.

38. The apparatus according to claim 36 or 37, characterized in that the bending comb is mounted on the compression unit in order to be able to move relatively in such a way that it rests on the first longitudinal edge before compressing the ram.

39. The apparatus according to claim 37 or 38, characterized in that the compression ram is configured as a welding tool and - a part of the mandrel is configured as an anvil. _

40. The apparatus according to claim 39, characterized in that at the end of the bending and bending operation, the overlapping region is compressed on the anvil through the compression unit and welded in any section or in the form of sealing by the tool of so l_d a du ra.

41. The apparatus according to one or more of claims 22 to 40, characterized in that the overlapping region is formed in a central region or in the region of a trailing edge of the hollow article and is compressed between a compression unit of multiple parts and a mandrel and is fixed at least in sections.