Method and device for improving the roundness of tube bodies and method and device for producing packaging tubes

Description

[0001] The present invention relates to a method for improving the roundness of tube blanks, hereinafter referred to as tube bodies, a method for producing packaging tubes from a tube body and a head for attachment to the tube body according to the preamble of claim 9, further to a device for improving the roundness of tube bodies for packaging tubes and finally to a device for producing packaging tubes from a tube body and a head for attachment to the tube body according to the preamble of claim 16.

[0002] Packaging tubes are typically made from a tube body and a head, with the head being connected to the tube body at one axial end. The second axial end of the tube body is usually left open for backfilling of the packaging tube and is only closed and sealed by the filler or packer.

[0003] The tubes or tube bodies, if they have plastic as their base material, are manufactured from a plastic laminate sheet, in which the different layers of the plastic laminate realize or enhance different functions of the tube or tube body. For example, barrier layers, layers for achieving sufficient mechanical stability, decorative outer layers, and various other layers can be provided in such a laminate.

[0004] The laminate is usually provided as a flat starting material and then formed into a tubular body and then joined to form a tube or continuous tube by creating a connecting seam, in particular a welded seam, at an overlap or butt point between two opposite ends of the laminate sheet. This weld extends in the longitudinal direction and is therefore also called a longitudinal seam. For further processing of the tube or continuous tube produced in this way, in particular for the manufacture of packaging tubes, the most complete or perfect geometric roundness of the cross-section of the tube is desired or intended. The best possible roundness is desired or required for technical reasons, for example for reasons of further processing when connecting to the tube head or during filling, as well as for reasons of handling or printing.However, the creation of the longitudinal seam or weld seam results in the formation of a more or less pronounced ovality or an overall deviation from a circular geometry of the cross-section due to the resulting material changes, stiffening, tension and other inhomogeneities.

[0005] The problem of the lack of roundness or ovality of the tubes or tube bodies is known in the state of the art and has already been addressed by various technical approaches.

[0006] For example, devices and methods are known that attempt to minimize ovality or improve roundness through thermal post-treatment or temperature exposure. This approach is known, for example, from EP 2 276 622 A1, CH 695 937 A5, and other disclosures, such as EP 2 188 110 A1.

[0007] CN 102 909 855 B also concerns a device for improving the roundness of endless tubes for tube bodies. The freshly welded endless tubes are to be deformed several times inward and outward before being separated in order to reduce the effects of the weld seam on the shape or cross-section of the endless tube. Both the deformation of the "freshly welded tubes" and the repeated alternating inward and outward deformation limit the possible degree of deformation and thus necessitate the described high level of plant engineering effort to positively influence roundness.

[0008] The known solutions counteract ovality on the endless tube, which then also affects the tube bodies separated from the endless tube.

[0009] However, it has been found that the known approaches to improving the roundness of tube bodies are not sufficient because, in terms of the result, i.e. the improvement in roundness, they are either not sufficient or not reliable enough, or they require too much effort in terms of device technology and process engineering to sufficiently improve the roundness.

[0010] Based on the known prior art, it is therefore the object of the present invention to propose methods and devices which allow the roundness of tube bodies, preferably made of plastic laminate, to be improved by simple means.

[0011] With regard to the method for improving the roundness of tube bodies for packaging tubes having a longitudinal seam, in particular a longitudinal weld seam, this object is achieved by the features of claim 1. With regard to a method for producing packaging tubes, this object is achieved by the features of claim 9. With regard to a device for improving the roundness of tube bodies for packaging tubes having a longitudinal seam, in particular a longitudinal weld seam, the object is achieved by the features of claim 11. Furthermore, the object is achieved by a device for producing packaging tubes from a tube body and a head for attachment to the tube body, with the features of claim 16.

[0012] Advantageous embodiments and configurations are the subject of the dependent claims as well as the following claim support and description of the figures.

[0013] The method for improving the roundness of tube bodies having a longitudinal seam, in particular a longitudinal weld seam, which are also known in technical jargon as "tube bodies", for packaging tubes, preferably as part of a packaging tube manufacturing process, comprises, in addition to the known method steps in the form of a transfer of individual tube bodies to a transport device and the transport of the tube bodies along a transport path with the transport device, also the method steps according to the invention, according to which the tube body undergoes a section-wise and / or temporary radial deformation inwards during transport along the transport path by the tube body passing through deformation means.

[0014] In the present description, unless otherwise stated, a radially inwardly directed deformation is to be understood as a deformation of a part of the surface of the tube body which acts substantially perpendicularly on the tube body and is directed towards a center or center of gravity of the tube body.

[0015] The basic idea of the present invention is based on mechanical compensation or mechanical reshaping of the tube bodies, which acts or acts inward on a section or a partial area of the circumference or cross-section of the tube body and thus reduces the ovality or, in other words, improves the roundness. The basic idea of the invention is that the tube bodies move on the transport device or in the transport device along the transport path past the deformation means, so that the interaction between the properties of the transport device on the one hand, such as transport speed, and the properties of the deformation means on the other hand, such as the degree of radial deformation, can be well adjusted, so that, on the one hand, a plastic deformation or a deformation with a plastic component takes place,which specifically improves the roundness or reduces the asymmetry, but at the same time ensures that the elastic components of the deformation or, in other words, the elastic restoring forces of the tube bodies are sufficient to return the tube bodies, after passing through the deformation means, to a state which has a fundamentally round cross-section of the tube bodies and, in addition, also an improved geometric roundness of the tube bodies.

[0016] The invention takes advantage of the finding that, compared to the continuous tube, the tube bodies can undergo significantly greater temporary and / or section-wise deformation without damaging the tube bodies, in particular without scratching or kinking them. This advantageously allows the method to be implemented with relatively simple device elements while still achieving an outstanding improvement in roundness. At the same time, it advantageously enables the method to be integrated into a packaging tube manufacturing process or a method for manufacturing packaging tubes, and particularly advantageously, it can also be subsequently integrated or retrofitted into known methods and devices.

[0017] It has also proven particularly advantageous that the method according to the invention, not least because of its simple implementation at the method and device level, can also be combined with already known approaches, devices and methods for improving the roundness of the tube bodies, and then supports or improves the other known or previously known mechanisms for reducing ovality.

[0018] The process is also characterized by the fact that the improvement in roundness is achieved without a mandrel or mandrel, which makes implementation in the device much easier.

[0019] Unless explicitly stated otherwise below, it should generally be assumed for the purposes of the following disclosure that the tube bodies are manufactured or produced from a multi-layer plastic laminate or at least a plastic-containing laminate.

[0020] Furthermore, for the purposes of this disclosure, it should be assumed that the tube bodies are individual tube bodies suitable for direct or immediate further processing into packaging tubes. This is intended to distinguish the term "tube body" in particular from a precursor or predecessor considered in terms of the process, namely an endless tube produced from a laminate by welding, which, according to the understanding of the present disclosure, only becomes a plurality of tube bodies through singulation processes. The endless tube, as the procedural predecessor of the tube body, is also referred to as a "sleeve" in the vocabulary of the person skilled in the art.

[0021] According to a first particularly advantageous embodiment of the method, it can be provided that a maximum radial deformation of the tube bodies occurs in a region of the longitudinal seam of the tube bodies. This means that the tube bodies and the deformation means are arranged or aligned relative to one another such that, viewed in the cross-section of the tube bodies, the deformation means act on the tube body from radially outside to radially inside and thereby come into contact substantially or directly with a section of the tube body in which the longitudinal seam is arranged or formed.In this case, it is advantageously achieved that the axial or longitudinally extending section of the longitudinal seam of the tube body, which essentially causes the distortion or deviation from a geometrically circular cross-sectional shape, is subjected to a maximum deformation and / or a maximum force effect, so that a plastic, irreversible deformation is most likely to be generated in this area and consequently stresses or material or structural properties that prevent or impair roundness can be advantageously influenced.

[0022] It can be provided that the tube bodies are fed onto the transport device with a specific orientation. Alternatively, the method or device can include an orientation step or an orientation unit that ensures that the tube bodies pass through the deformation means in the desired orientation, so that the area of the longitudinal seam experiences the maximum deformation radially inward.

[0023] In a further, particularly advantageous embodiment of the method, it can be provided that the deformation by the deformation means transforms or at least temporarily transforms the tube bodies into a cross-section that simulates a U-shaped or V-shaped contour, wherein the longitudinal seam of the tube bodies is arranged in the region of a mirror symmetry axis of the deformed contour or the deformed cross-section.By means of the said deformation, which can occur, for example, when a deformation means deforms the tube body in a radial direction directed towards the centre or centre of gravity of the approximately circular cross-section of the tube body, it can be advantageously achieved at the same time that the greatest possible permanent or plastic effect takes place in the region of the longitudinal seam, while at the same time in regions of the tube body - in the circumferential direction - which are further away from the seam or longitudinal seam, essentially elastic deformations are carried out, which therefore do not adversely affect the roundness of the tube body and also provide or build up the necessary restoring forces in order to return the tube body to an initial shape or an initial cross-section, or better said to a circular cross-section which is improved compared to the initial cross-section, after the action of the deformation means.When deforming into a U-shaped or V-shaped cross-section, especially when the mirror symmetry axis runs in the area of the longitudinal seam, curvatures arise in the area of the longitudinal seam and the adjacent areas that run in the opposite direction to the original curvature of the circular or slightly oval cross-section. This reversal of the curvature ratios makes it particularly effective to influence stiffeners, bracing, or other properties that counteract a geometrically round shape of the tube body's cross-section.

[0024] In a further, particularly preferred embodiment of the method, it can be provided that the rotation of the tube bodies around a longitudinal axis is prevented by means of guide means along the transport path, or at least along part of the transport path. This also means that, at least during part of the transport of the tube bodies along the transport path, and in particular also during the action of the deformation means, the contact surfaces or contact areas between the transport device and the tube bodies remain constant or unchanged. The guide means can, for example, be formed as part of the transport device. For example, the transport device can have a rubberized belt with a V-shaped profile ("V-belt"), so that the rubberized contour of the belt prevents rotation of the tube bodies on the transport device, in particular also during the action of the deformation means.Alternatively, the guide means can also be implemented by several, preferably four, belts. The belts can also be rubberized and / or arranged in the shape of a rectangle or square around the tube body. The belts can preferably be driven to transport the tube bodies. Advantageously, in both embodiments, parts of the transport device can also provide the guide means, so that they simultaneously contribute to or support the transport along the transport path and prevent the tube bodies from rotating around their longitudinal axis.

[0025] This ensures that the tube bodies are applied to the transport device in a defined position and with a defined orientation and are transported in this position and orientation and are influenced, in particular deformed, by the deformation means.

[0026] Furthermore, it can advantageously be provided that along the transport path, at least in sections, preferably over the entire extent or extension of the deformation means in the direction of the transport path, lateral deformation of the tube bodies is limited by lateral guide elements. The lateral guide elements can be designed, for example, as side walls or as lateral guide profiles or as guide bodies concave towards the transport device, for example guide rollers, which on the one hand prevent the tube bodies from being pushed away by the deformation means and at the same time laterally limit or restrict the deformation of the tube body within a range of approximately ± 90° relative to the position of the longitudinal seam. In this way, the deformation can be particularly advantageously limited in areas that would otherwise counteract or reduce the targeted cold forming or hot forming in the region of the longitudinal seam.At the same time, this ensures that no tube bodies are removed from the transport device, in particular pushed out, under the influence of the deformation means.

[0027] In a further advantageous embodiment of the method, it can be provided that the deformation is varied along the transport path by the deformation means extending at different distances in the direction of the tube bodies and / or the transport device at different points along the transport path. In this context, it can be particularly preferably provided that in a first section of the deformation means a slight or moderate deformation takes place, which then increases with increasing transport along the transport path. In an end section of the deformation path, i.e. the section on which the deformation means act on the tube bodies, it can be provided that the deformation either gradually decreases again or that the deformation is suddenly canceled.If the deformation is suddenly released, the elastic prestressing of the deformed tube bodies can be advantageously utilized to return to the original or improved shape. However, there is a risk of highly uneven reshaping, which in the worst case could leave kinks or other damage or impairments on the tube body. Gradual release or reduction of the deformation reduces the risk of damaging the tube bodies. At the same time, however, care must be taken to ensure that the tube bodies are completely returned to a state where the desired, improved cross-sectional shape is achieved compared to the initial situation.

[0028] In a further, particularly advantageous embodiment of the method, it can be provided that the deformation means at least temporarily produces a radial deformation of a part of the surface of the tube body of more than 40%, preferably more than 60%, particularly preferably more than 80%, in particular more than 95% of the tube diameter or tube pipe diameter. In other words, this means that the section of the tube body, viewed in the circumferential direction, which has the longitudinal seam is deformed inwards at least up to a region that is located approximately in the region of the center point or center of gravity of the originally undeformed tube body. In an extreme case, for example with a deformation of 95% or more, the longitudinal seam is deformed at a maximum deformation up to or almost up to the side of the tube body that is opposite in the originally undeformed state.

[0029] The degree of maximum deformation required depends essentially on the original ovality or the degree of lack of roundness prior to deformation. As will be discussed later, temperature, particularly the temperature of the longitudinal seam at the time or during the deformation period, is also an influencing factor and can thus influence or determine the necessary deformation or the necessary degree of deformation, relative to the original diameter, required to achieve an improvement in roundness.

[0030] In a further advantageous embodiment of the method, it can be provided that the deformation means has a contact surface for contacting the tube body, which moves with the tube body when it comes into contact with the tube body or slides along it without friction. This essentially ensures that the outside of the tube body is not damaged, in particular not scratched. The deformation means, which can be designed as a plurality of individual deformation elements, for example, can have a circular contact surface, for example by being constructed as wheels or disks, in which case the speed of the contact surface is or must be the same as the transport speed of the tube body on the transport device, in order to ensure that the contact surface moves with the tube body and slides along it and precisely does not drag, rub or the like against it.The deformation means can also be designed, for example, as a continuous endless belt, with the part of the endless belt facing the transport device at any given time forming the contact surface. In this case, too, it must be ensured that the speed of movement in the direction of the transport path is the same as that of the tube bodies on the transport device.

[0031] Another particularly advantageous variant of the method provides for the deformation means to be cooled, at least during operation, using an active cooling process. This allows heat to be dissipated from the tube body, preferably from the region of the longitudinal seam, in the deformed state or deformation state of the tube body. This then leads to the properties and conditions of the deformation state being better preserved or maintained, so that the roundness of the tube body can be better achieved and maintained after it returns to its improved original cross-sectional shape.

[0032] Furthermore, it can advantageously be provided that the deformation means are driven such that the movement of the deformation means and their contact surfaces and the movement or direction of movement of the transport device are in the same direction, in particular at the same speed. It is of particular interest to ensure that no friction is generated between the deformation means, in particular the contact surfaces of the deformation means and the tube bodies, especially in the region of the longitudinal seam. To ensure this, a proposed embodiment can preferably be provided in which the deformation means themselves are actively driven. The drive should then be adjusted as precisely as possible so that the tangential speeds of the deformation means in the direction of the transport path are identical to the speed of the transport device and / or the tube bodies located thereon.

[0033] Furthermore, according to a particularly preferred embodiment, the deformation can begin in a state of the tube body in which the longitudinal seam of the tube body has a temperature of more than 40°C, preferably more than 50°C. This advantageously ensures that the connecting seam or the longitudinal seam is not yet fully cured, which in turn facilitates an effect on the longitudinal seam to improve roundness. It can be particularly advantageous in this context if the deformation means and / or the tube body itself is cooled in the deformed state or deformed state, since then a curing or fixing of the longitudinal seam, which promotes roundness, takes place or is accelerated in the deformed state.The temperature of the weld seam at the start of deformation can, for example, be adjusted or determined by a spatial and / or temporal interval between the creation of the weld seam and the deformation of the tube body, and the corresponding arrangement of the associated deformation means. The closer the deformation means are brought or positioned, both temporally and spatially, to the location or point where the longitudinal seam is created, the higher the temperature or residual heat of the weld seam or longitudinal seam at the start of deformation.

[0034] Particularly advantageously, the deformation of the tube bodies can take place over a period of more than 0.5 s. This can be particularly advantageous to ensure that sufficient deformation takes place and that the deformation has a lasting effect on the final cross-section of the tube bodies, for example, by cooling the longitudinal seam in the deformed state or otherwise solidifying or curing it.

[0035] Overall, the duration of the deformation and the temperature range in which the deformation takes place are advantageously adapted to the material system of the laminate. For example, higher temperatures may be advantageous for specific laminate systems.

[0036] A further, particularly advantageous embodiment, as already discussed above, provides that the tube body, in particular the region of the longitudinal seam of the tube body, is cooled during deformation or is actively exposed to or brought into contact with a coolant or cooling medium. This can be achieved, for example, by one or more nozzles that apply cold air or another heat-transporting fluid, for example, water, toward the surface of the tube body in the region of the longitudinal seam, thus cooling the longitudinal seam or dissipating heat from the region of the longitudinal seam.

[0037] The above-mentioned object is also achieved with a method for producing packaging tubes from a tube body and a head for attachment to the tube body, in particular for attachment to an axial end of the tube body, in which method, according to the invention, a method for improving the roundness of a tube body having a longitudinal seam, in particular a longitudinal weld seam, according to one of the previously described embodiments is used. The basic idea of the invention is to incorporate or include the method for improving roundness in the tube manufacturing process, so that an improved roundness of the tube body is produced before the head or tube head is attached or fastened.

[0038] According to an advantageous embodiment, the tube bodies can be separated from a continuous tube before the deformation is carried out. Preferably, the formation or creation of the longitudinal seam can be carried out before the deformation begins and before the separation takes place.

[0039] Furthermore, it can advantageously be provided that the deformation is carried out while the tube bodies are fed to a device for attaching the header or while the tube bodies are being processed in the device for attaching the header. Both variants make it particularly advantageous that the basic process sequence does not have to be changed or is otherwise impaired. In other words, the integration of the deformation into the device for attaching the head or into a feed area to the device for attaching the head means that the original process and material flow as well as the associated cycle times can be retained. This also means that the retrofitting of the process for improving roundness into existing processes for producing packaging tubes is particularly preferably enabled.

[0040] With regard to a device for improving the roundness of tube bodies for packaging tubes having a longitudinal seam, in particular a longitudinal weld seam, preferably as part of a packaging tube manufacturing device, comprising a transport device for receiving and transporting individual tube bodies along a transport path, the above-mentioned object is achieved in that deformation means are provided which are arranged such that during transport along the transport path the tube bodies experience a section-wise and / or temporary radial deformation inwards in that the transport device transports the tube bodies past the deformation means.

[0041] To avoid unnecessary repetition, all features, properties, and advantages disclosed by the method shall also be deemed to be disclosed by the device. The same applies to the device features and their properties and advantages that are also deemed to be disclosed by the method.

[0042] With the device according to the invention, as with the method according to the invention, the lack of roundness of the tube bodies is improved with relatively little design effort or effort in terms of device features. Furthermore, the device is fundamentally suitable for integration into an existing process or into an existing device for producing packaging tubes. This is because the deformation means can be arranged, for example, in the transport section between the separation of the individual tube bodies and the device for attaching the header. Alternatively, the deformation means can also be integrated into the device for attaching the header.

[0043] According to a first advantageous embodiment of the device, the deformation means can comprise a plurality of individual deformation elements. For example, the deformation elements that together form the deformation means can be designed as individual rotatably mounted and / or driven discs or disc wheels or the like. This advantageously allows for the construction or structural design of the deformation means to be implemented particularly easily.

[0044] Advantageously, it can be provided that the deformation means are arranged in a fixed position in an absolute position or fastening position with respect to the transport path and / or the transport direction. Accordingly, this can also apply to the deformation elements to the same extent if the deformation means are formed by a plurality of deformation elements. The fixed arrangement or mounting of the deformation means / deformation elements also enables a structurally simple design. However, it can simultaneously be provided that the mounting and / or arrangement of the deformation means is variable in the direction perpendicular to the transport path and / or the transport direction, namely directed toward the transport device.Thus, the degree of deformation of the tube bodies can be changed for the deformation means or for individual deformation elements by positioning or arranging the deformation means or deformation elements further or closer to the transport device.

[0045] Preferably, the deformation elements are designed as rotatably mounted discs or disc wheels, the respective bearing points of which are arranged along the transport path. This allows the tube bodies to pass through various discs one after the other and be deformed separately by each disc or disc wheel during the transport.

[0046] Furthermore, it can advantageously be provided that the radially outer regions of the deformation means or deformation elements form a contact surface for contacting the tube bodies. Preferably, the contact surfaces of the deformation means or deformation elements can be curved, in particular convexly curved, transversely to the direction of the transport path or transversely to the longitudinal direction of the tube bodies in order to prevent the tube bodies from kinking or bending in the deformed or deformed state.

[0047] Furthermore, it can advantageously be provided that the contact surface of the deformation means or deformation elements has a different distance from the transport means at different locations along the transport path. This allows the deformation of the tube bodies by the deformation means or deformation elements to be achieved to varying degrees along the transport path or along the extent of the deformation means.

[0048] Furthermore, it can particularly preferably be provided that guide means are arranged along the transport path, which prevent rotation of the tube bodies about a longitudinal axis. The guide means can, for example, be integrated into the transport device or interact with the transport device. For example, it can advantageously be provided that a rubberized conveyor belt or belt with a V-shaped profile (V-belt) ensures that the tube bodies are not twisted or rotated about their longitudinal axis after they have been picked up or received by the transport device.

[0049] Furthermore, it can advantageously be provided that lateral guide elements are arranged along the transport path, at least in sections, preferably over the entire extent or dimension of the deformation means, and limit lateral deformation of the tube bodies. The lateral guide elements are preferably arranged on both sides of the transport device and are preferably dimensioned such that the lateral guide elements extend at an end facing away from the transport device and towards the deformation means up to at least 50%, preferably up to at least 70% of the original diameter of the undeformed tube bodies. The lateral guide elements can preferably be designed as concave rollers or rollers with a concave outer surface, which are arranged on both sides of the transport device in a rotating manner perpendicular to the transport direction.

[0050] Particularly preferably, it can also be provided that the deformation means or deformation elements are designed to cooperate with cooling elements that enable active cooling of the deformation means or deformation elements during operation. The cooling elements can be designed, for example, as nozzles that apply a cooling fluid to the deformation means, deformation elements, and / or their contact surface. Alternatively, however, it can also be provided that the cooling elements ensure the transport of cooling fluid into and out of the interior of the deformation means or deformation elements, thus enabling a type of internal cooling of the deformation means or deformation elements.

[0051] According to a further preferred embodiment, a cooling unit can be provided, which is configured to cool the tube bodies, in particular the longitudinal seam of the tube bodies, during at least part of the action of the deformation means. This promotes stabilization, hardening, or solidification of the longitudinal seam in the deformed state or deformation state, which then contributes to improved roundness of the tube bodies after the deformation is removed or after passing through the deformation means.

[0052] The above-mentioned object is also achieved by a device for producing packaging tubes from a tube body and a head for attachment to the tube body, in that the device comprises a device, as described in the preceding embodiments, for improving the roundness of a tube body having a longitudinal seam, in particular a longitudinal weld seam. As already explained above, the device for improving roundness can be particularly advantageously integrated into a known or generic device for producing packaging tubes, or even retrofitted.

[0053] It can be particularly advantageous to provide a separating device for separating tube bodies from an endless tube, wherein the separating device is arranged such that the separation is completed before the deformation means come into contact with the tube bodies.

[0054] It can be particularly advantageous for the deformation means to be arranged between a separating device and a device for attaching the head or to be formed as part of the device for attaching the head.

[0055] The following are examples of embodiments, advantages, and effects of the present invention, based on purely schematic, exemplary drawings. In these drawings: Fig. 1: different cross-sections of tube bodies; Fig. 2: a generic device for producing packaging tubes; Fig. 3: an exemplary representation of a device according to the invention for improving the roundness of tube bodies and a section of a device according to the invention for producing packaging tubes; Fig. 4a: a cross-section through the plane A - A of the Fig. 3 ; Fig. 4b: a modified embodiment of the Fig. 3 or 4a. Fig. 5: exemplary cross-sections of a temporarily and sectionally deformed endless tube and a temporarily and sectionally deformed tube body.

[0056] The Fig. 1 shows two tube bodies 01 in a cross-sectional view. The left-hand tube body 01 shows a desired state of the cross-section. This is characterized by a completely or largely circular cross-section. The right-hand side shows the realistic cross-sectional shape or an actual cross-section of a tube body 01 after production from a plastic laminate, wherein a longitudinal seam 03, in particular a weld seam, is present or exists in a seam region 02 of the tube body 01, at which two opposite sides or ends of the laminate were connected to one another, in particular welded to one another, butt-jointly or with a spatial overlap.

[0057] It is in the Fig. 1 It can already be seen that the roundness of the actual cross-sections of the tube bodies 01 is insufficient or insufficient, especially for further processing of the tube bodies 01. Therefore, it is necessary and desired to adapt the cross-sectional shape more closely to the optimal or desired target shape of the left side of the Fig. 1 to approach.

[0058] The Fig. 2 shows, by way of example, a generic device 04 for producing packaging tubes. The film or plastic laminate 05 is introduced into the device 04 from the right and guided around a mandrel (not shown in detail). In the joining unit 06, two opposite ends of the laminate are then joined, in particular welded, to form a longitudinal seam (not shown in detail). The thus-produced endless tube 07 leaves the joining unit and is fed to a separating or separating device 08, which may, for example, have a knife or other cutting or separating device and divides the endless tube 07 into individual, separate tube bodies 09.

[0059] After separation or singulation, the tube bodies 09 are transferred to a transport device 10 and conveyed further along a transport path 11 by the transport device 10. The transport device 10 is generally operated at a higher speed than the longitudinal seam welding process or the singulation process, which results in a spatial separation or singulation after the tube bodies 09 are cut or singulated from the endless tube 07. A lower speed on the part of the transport device is also possible in principle if the tube bodies 09 are suitably rotated about an axis perpendicular to the transport direction 12.

[0060] The positions of the individual tube bodies 09 can be recorded on the transport line 11. Advantageously, the tube bodies 09 can also be examined with an optical system or other measuring system to prevent them from entering the device 13 for attaching the tube header if certain quality characteristics are not met. The latter removal can be achieved, for example, by blowing them out with compressed air. Tube bodies 09 can also be separated or removed along the transport line for manual quality inspections.

[0061] In the Fig. 3 A modified variant of a device 04 is shown, in which a device 24 according to the invention for improving the roundness of the tube bodies 09 is mounted or integrated between the device 13 for attaching the heads and a separating device 08. This device comprises deformation means 14 arranged above the transport device 10, which are designed as a plurality of individual deformation elements 15. The deformation means 14, in particular the individual deformation elements 15, are designed with a different distance from the transport device 10. In the illustration of the Fig. 3 It can already be seen that the deformation elements 15 cause a deformation of the tube bodies 09 to take place radially inwards from above or from the transport device opposite, which is canceled again after the deformation means 14 or the last deformation element 15 have been passed.

[0062] In order to limit the deformation to the side, i.e. perpendicular to the plane of the drawing, the device has lateral guide elements 16 arranged on both sides of the transport device 10, which extend over a part, but preferably over the entire extent of the deformation means 14. The lateral guide elements 16 are designed as rotatably mounted rollers arranged on both sides with a concave surface or lateral surface, which can be seen from the Fig. 4 is even more clearly visible.

[0063] The deformation elements 15 are designed, for example, as wheels or disc wheels and have a contact surface 17 on their radial outer side, which in turn is connected to the tube bodies 09 in order to deform them radially inward. The deformation means 14 or deformation elements 15 can preferably be designed to be driven to ensure that the contact surface 17 merely slides or rolls onto the tube body 09, but that no grinding or slippage occurs between the tube bodies 09 and the deformation means / deformation elements 14, 15. This prevents any influence on the outer surface of the tube bodies 09, in particular, scratching.

[0064] In the presentation of the Fig. 4 is a section along the plane AA of the Fig. 3 This shows, on the one hand, the design of the lateral guide elements 16 as rotatably mounted rollers with a concave surface. It can also be seen that the tube bodies 09 are guided by guide means 18, which in the example of the Fig. 4 are formed as part of the transport device 10 and secured against rotation about the longitudinal axis. The guide means 18 are designed, for example, in the form of a V-profile and, furthermore, in the form of a rubber coating of the conveyor belt 19 of the transport device 10. In the Fig. 4 It can also be seen that the deformation elements 15 advantageously have a convexly curved contact surface 17 in order to prevent or minimize kinking on the side of the tube body 09. The Fig. 4 also shows the deformation of the tube body 09 toward a cross-section with a U-shaped or V-shaped contour. The deformation elements 15 extend along a mirror-symmetry axis 23. Furthermore, the tube body 09 is arranged such that the contact surface 17 acts, if possible, precisely on the longitudinal seam 03, in particular the weld seam, and deforms it radially inward relative to the undeformed cross-section of the tube body.

[0065] In the Fig. 4 Cooling elements 22 are also provided, for example, which are designed to interact with the deformation means 14 or the deformation elements 15 and enable active cooling of the deformation means 14 or the deformation elements 15 during operation. The cooling elements 22 can be designed, for example, as cooling nozzles. A cooling unit (not shown in detail) can also be provided, which is designed to cool the tube body 09, in particular the longitudinal seam 03, during at least part of the action of the deformation means 14 or the deformation elements 15.

[0066] As an alternative to the conveyor belt 19 of the transport device 10, which is designed as a rubberized V-belt, a conveyor chain can also be provided as the transport device 10. Another alternative of the transport device 10 is shown in the Fig. 4b Here, the transport device 10 comprises four rubberized, driven belts 25, which can be designed, for example, as endless belts. Fig. 4b shows only the sections of the belts 25 in cross-section that come into contact with the tube tube. The belts also form guide means 18, which prevent rotation of the tube body 09 about the longitudinal axis in the same way as the guide means 18 of the Fig. 4a .

[0067] In the Fig. 4a und 4b It can also be seen that the deformation transforms the tube body 09 into a cross-section that simulates a U-shaped or V-shaped contour, wherein the longitudinal seam 03 is arranged in the region of a mirror symmetry axis 23 of the contour or the cross-section.

[0068] The Fig. 5 shows on the left side a cross-section of an endless tube 07, which in a known manner according to the prior art already undergoes a deformation in order to reduce the ovality of the endless tube 07 and thereby also improve the roundness of the subsequently separated tube bodies 09. This endless tube profile or this endless tube cross-section 20 shows a deformation that deforms the seam 03 or weld seam only up to about 40% of the original diameter of the endless tube 07. In contrast, the right side of the Fig. 5 a tube body 09 according to the present invention or in a deformation state according to the present invention. The tube body 09 is deformed by more than 40%, preferably more than 80%, and in exceptional or extreme cases even up to 100% of the diameter of the original tube body, so that in said extreme case, the longitudinal seam 03 can even touch the opposite wall 21 of the tube body 09. This also means that the invention is based on the finding that an isolated tube blank 09 can be deformed significantly more than an endless tube 07 without suffering damage or other negative impairments to the tube body 09. Due to the greater deformation, the ovality can be better counteracted. If, on the other hand, the endless tube 07 is deformed too much, it tends to buckle, whereupon the manufacturing process is interrupted. The Fig. 5The strong deformation shown in the example in the area of the longitudinal seam 03 leads to a strong curvature of the wall of the tube body 09 in this area, resulting in a permanent, counter-oval and thus plastic deformation. By selecting the appropriate deformation depth and curvature radius, the resulting shape and thus the roundness can be optimized. Reference symbol

[0069] 01Tube body 02Seam area 03Longitudinal seam / seam 04Device 05Plastic laminate 06Connecting unit 07Endless tube 08Separating unit 09Tube body 10Transport device 11Transport path 12Transport direction 13Device for attaching heads 14Deformation means 15Deformation elements 16Side guide elements 17Contact surface 18Guiding means 19Conveyor belt 20Endless tube cross-section 22Cooling elements 23Mirror symmetry axis 24Device 25Belt

Claims

1. A method for improving the roundness of tube bodies (09) having a longitudinal seam (03), in particular a longitudinal weld seam, and intended for packaging tubes, preferably as part of a packaging-tube production method, the method comprising the following steps: - transferring the individual tube bodies (09) to a transport unit (10). - transporting the tube bodies (09) along a transportation path (11) using the transport unit (10); the tube body (09) being subjected to radial inward deformation in sections and / or temporarily during transportation along the transportation path (11) by the tube body (09) passing through deforming means (14).

2. The method according to claim 1, characterized in that a maximum radial deformation in the area of the longitudinal seam (03) of the tube body (09) takes place and / or the deformation reshapes the cross section of the tube body (09), the cross section replicating a U-shape or V-shape contour, the longitudinal seam (03) being disposed in the area of a mirror-symmetry axis (23) of the contour or the cross section.

3. The method according to claim 1 or 2, characterized in that a rotation of the tube bodies (09) about a longitudinal axis is prevented along the transportation path (11) by means of guide means (18).

4. The method according to any one of the claims 1 to 3, characterized in that a lateral deformation of the tube bodies is limited along the transport path (11), at least in sections, preferably the entirety of the extension or length of the deforming means (14), by lateral guide elements (16).

5. The method according to any one of the claims 1 to 4, characterized in that the deformation along the transport path (11) is varied by the deforming means (14) extending towards the tube bodies (09) and / or the transport unit (10) at varying depths and at different positions along the transport path (11).

6. The method according to any one of the claims 1 to 5, characterized in that the deforming means (14) at least temporarily generate a radial deformation of a part of the surface of the tube bodies (09) of more than 40%, preferably more than 60%, particularly preferably more than 80 %, of the originally undeformed tube diameter.

7. The method according to any one of the claims 1 to 6, characterized in that the deforming means (14) have a contact surface (15) for abutment against the tube bodies (09), the contact surface (15) moving along with the tube bodies (09) when abutting against them.

8. The method according to any one of the claims 1 to 7, characterized in that the deformation begins in a state of the tube body (09) in which the longitudinal seam (03) of the tube body (09) has a temperature of more than 40 °C, preferably more than 50 °C.

9. A method for producing packaging tubes of a tube body (09) and a head for attachment on the tube body (09), characterized by a method for improving the roundness of tube bodies (09) having a longitudinal seam (03), in particular a longitudinal weld seam, according to any one of the claims 1 to 8.

10. The method according to claim 9, characterized in that the deformation is carried out while the tube bodies (09) are supplied to a unit (13) for attaching the head or while the tube bodies (09) are processed in the unit (13) for attaching the head.

11. A device for improving the roundness of tube bodies (09) having a longitudinal seam (03), in particular a longitudinal weld seam, and intended for packaging tubes, preferably as part of a packaging-tube production device, the device comprising a transport unit (10) for receiving and transporting individual tube bodies (09) along a transport path (11) and deforming means (14) which are disposed in such a manner that the tube bodies (09) are subjected to a radial inward deformation in sections and / or temporarily during transport along the transport path by the transport unit (10) transporting the tube bodies (09) past the deforming means (14).

12. The device according to claim 11, characterized in that the deforming means (14) comprise a plurality of individual deforming elements (15).

13. The device according to claim 11 or 12, characterized in that the deforming elements (15) are designed as rotationally mounted disks whose mounting points are disposed along the transport path (11).

14. The device according to any one of the claims 11 to 13, characterized in that a rotation of the tube bodies (09) about a longitudinal axis is prevented along the transport path (11) by means of guide means (18).

15. The device according to any one of the claims 11 to 14, characterized in that lateral guide elements (16), which are disposed along the transport path (11) at least in sections, preferably across the entire extension or length of the deforming means (14), limit a lateral deformation of the tube bodies (09).

16. A device for producing packaging tubes from a tube body (09) and a head for attachment on the tube body (09), characterized by a device for improving the roundness of tube bodies (09) having a longitudinal seam (03), in particular a longitudinal weld seam, according to any one of the claims 11 to 15.