METHOD AND DEVICE FOR MAKING BAGS

Description

[0001] The present invention relates to a method and a device for producing bags from film, preferably tobacco bags, in which a film web is welded at a welding station to at least one of two detachably connectable profile strips of a multi-action pressure closure, such as a so-called Zip-Lock ®< , in particular by means of ultrasound.

[0002] After such profile strips have been welded to the film web during bag production, the film web often subsequently wrinkles in the welded area. This is primarily due to the fact that the film web and the printing strip are usually conveyed along the welding station using tensile forces, stretching to different degrees due to the material, and then later, i.e. when the tensile forces are removed, contracting again to different degrees. The profile strip usually contracts more than the film, resulting in the film wrinkling described above. This effect is reinforced or supplemented by the fact that the printing strip and the film web are initially stretched during welding due to the associated heating and then, when they cool down, also contract again - depending on the material.

[0003] JP H09 39121 A discloses welding a profile strip and a film along the circumferential surface of a rotating drum using a correspondingly curved sealing element. The profile strip is guided in a groove recessed into the circumferential surface of the rotating drum.

[0004] JP 2016 198919 A ​​also provides for the profile strip and film to be pulled taut and connected to each other on the circumferential surface of a rotating drum.

[0005] JP 2007 283637 A describes a device in which a profile strip and a film are first guided along heating blocks and heated up. They are then joined together by two pressure rollers.

[0006] EP 1 681 155 A2 discloses a manufacturing method for a hook and loop fastener, in which a hook and loop fastener strip is conveyed parallel to a film and is connected to the film by a sealing shoe which exerts pressure and heat perpendicularly on the hook and loop fastener strip.

[0007] EP 2 441 685 A1 describes a method and a device in which two profile strips of a pressure closure are positioned on the edges of a film by rollers having a groove on the peripheral surface which receives the respective profile strip, and are then connected to the film.

[0008] Based on this, it is the object of the present invention to further develop the method and device mentioned at the outset, in particular to counteract the aforementioned wrinkling.

[0009] This object is achieved by a method having the features of claim 1 and a device having the features of claim 10.

[0010] According to the invention, a method of the type mentioned at the outset for producing bags from film is characterized in that the profile strip is subjected to compressive forces acting in the longitudinal direction during welding and counteracting the formation of wrinkles in the film web.

[0011] It has surprisingly been shown that by subjecting the profile strip to this type of pressure, at best the formation of wrinkles can be completely avoided. But at the very least it can be reduced. According to current knowledge, this is achieved by compressing the profile strip before welding and creating compressive stress therein. This causes the profile strip to relax upon cooling after welding and ultimately contract less than would be the case without the compressive forces being applied. This compensates for the differences in the stretching behavior of the profile strip on the one hand and the film on the other. The same applies to the different stretching behavior if the profile strip and the film are stretched by applying tensile forces.

[0012] It is understood that, as a rule, both profile strips of the pressure seal are connected to the film web, and accordingly, the other profile strip can or should also be subjected to compressive forces in the manner according to the invention in order to prevent or counteract wrinkling of the film during the welding of this other profile strip. In this respect, all features or measures described in this application as examples for one profile strip can also be provided for the other profile strip.

[0013] According to the invention, the compressive forces are applied to the profile strip by means of a force transmission element, in particular a force transmission roller, which acts on the profile strip and in particular faces one side of the profile strip. In particular, a force transmission element which has one or more, preferably serrated, force transmission elements which act on the profile strip, in particular on one side of the profile strip, to transmit the compressive forces. As an alternative to the aforementioned force transmission roller, other force transmission elements could also be used. For example, an element which moves back and forth in a linear, cyclical manner parallel to the conveying direction and which has serrations (serrated comb) and which engages the profile strip during a forward movement but not during a return movement.Two such elements could also be provided which act alternately on the profile strip, so that overall, despite the cyclical movement which only transmits compressive forces to the profile strip during the respective feed movement, compressive forces can nevertheless be transmitted continuously to the profile strip.

[0014] Insofar as reference is made in this application to the "sides" of the profile strip or film web, this naturally refers to their two large-area sides and not to their narrow longitudinal edges at which these large-area sides adjoin or connect them.

[0015] Preferably, the film web and the profile strip can be conveyed continuously along the welding station while they are being welded together. However, it is also within the scope of the invention to convey the film web and the profile strip intermittently.

[0016] Preferably, the film web and the profile strip can be subjected to tensile forces, in particular generated by preferably motor-driven (possibly a servomotor) conveyor elements, preferably tension rollers, in order to convey the film web and the profile strip in a conveying direction along the welding station. The compressive forces can be applied in addition to the tensile forces, preferably in the conveying direction of the profile strip. In particular, compressive forces that are greater than the tensile forces.

[0017] According to the invention, the profile strip is guided laterally in the area of ​​the welding station by a guide means that, in particular, slides against the profile strip and / or the film web, in order to prevent lateral buckling of the profile strip caused by compressive forces. This is particularly achieved by a guide means that faces one side of the profile strip.

[0018] The guide means can in particular be a guide roller rolling on the film web and / or the profile strip or a guide rail which in particular slides against the profile strip and / or the film web.

[0019] Such a guide means can be arranged on one or both sides of the profile strip or the film web.

[0020] According to the invention, the guide means is arranged between the force transmission element and the support element relative to the longitudinal direction or conveying direction of the profile strip. Preferably, it faces the same side of the profile strip as the force transmission element and the support element.

[0021] According to the invention, the film web, while carrying the profile strip, is pressed by a welding element arranged downstream of the force transmission element during the welding process against a contact means opposite the welding element, which is facing the same side of the profile strip as the force transmission element.

[0022] Preferably, the profile strip can be guided laterally by a further guide means, wherein one guide means faces one side of the profile strip and the other guide means faces the other side of the profile strip.

[0023] As regards the speed component of the force transmission element which is effective in transmitting the compressive forces to the profile strip, in particular the peripheral speed of the force transmission roller, this may be 10% to 50%, preferably 30%, greater than the speed at which the film web is moved.

[0024] The contact means can be a contact roller, in particular one driven in a rotatable manner (possibly by a servo motor), the rotational speed of which is preferably lower than the rotational speed of the power transmission roller.

[0025] According to a further embodiment of the inventive concept, it can be provided that the speed component of the force transmission element, which is effective when transmitting the compressive forces to the profile strip, in particular the circumferential speed of the force transmission roller, is controlled or regulated according to the speed, temperature and / or the material type of the film, the film web and / or the profile strip. In particular, in such a way that an associated target value for the speed component is stored in a memory for several speed, temperature and / or material type values ​​of the film, the film web and / or the profile strip, in particular in a table, and that this target value is selected for controlling or regulating the force transmission element according to the respective actual value of the speed, temperature and / or the material type of the film, the film web and / or the profile strip.

[0026] It may also be provided to measure the temperature of the film, the temperature of the profile strip, the temperature of the welding element and / or the temperature of the attachment means and, depending on this, to regulate the speed component of the force transmission element which is effective in transmitting the compressive forces to the profile strip and / or the power of the welding element.

[0027] Furthermore, it can be provided that the film web is monitored after the welding process, in particular downstream of the welding station, with a particularly electro-optical testing device, preferably a line sensor, with regard to the formation of wrinkles in the film web, and that the speed component of the force transmission device, which is effective when transmitting the compressive forces to the profile strip, is automatically changed, in particular is regulated, in order to counteract the formation of wrinkles, should the testing device detect a wrinkle formation or a wrinkle formation that exceeds a predetermined level, and / or the performance of the welding device.

[0028] A device according to the invention for producing bags from film, which is particularly suitable for carrying out the method described above, has a welding station at which a film web is welded to at least one of two profile strips of such a multi-action pressure closure by means of a welding element, in particular an ultrasonic welding element, and a force transmission element, in particular a force transmission roller driven in rotation (optionally with a servo motor), with which compressive forces acting in the longitudinal direction of the profile strip can be introduced into the profile strip during the welding process and counteracting the formation of wrinkles in the film web.

[0029] The force transmission element, in particular the force transmission roller, can have one or more, preferably tooth-shaped, force transmission elements which act on the profile strip to transmit the compressive forces, in particular on one side of the profile strip.

[0030] The device according to the invention, in particular the welding station thereof, further comprises a guide means that guides the profile strip on at least one side to prevent the lateral buckling of the profile strip caused by compressive forces, as outlined above. In particular, a guide means that faces one side of the profile strip.

[0031] According to the invention, the welding station has a contact means arranged opposite the welding element, which faces the same side of the profile strip as the force transmission element and is arranged downstream thereof, wherein the film web and the profile strip are guided between the welding element and the contact means, and wherein the film web and the profile strip can be pressed together by the welding element against the contact means, in particular against a contact surface of the contact means, during the welding process.

[0032] According to the invention, the guide means, in particular a guide roller or a guide rail, is arranged between the force transmission member and the contact means, preferably in such a way that it faces the same side of the profile strip as the force transmission member and the contact means.

[0033] The device, in particular the welding station thereof, can have a further guide means which guides the profile strip laterally or on its side in order to prevent lateral buckling of the profile strip caused by the compressive forces, wherein one guide means faces one side of the profile strip and guides it there, and wherein the other guide means faces the other side of the profile strip and guides it there.

[0034] As far as the contact means is concerned, it can be a rotatable contact roller, in particular one driven by a motor (possibly a servo motor), in particular a contact roller with individual, separate contact surfaces distributed over the circumference.

[0035] The contact means may have an (internal) cooling system, in particular for cooling the contact surface(s), preferably an electrically operated cooling system or a cooling system based on cooling liquids.

[0036] As far as the welding organ is concerned, it can be designed as a rotary or translatory ultrasonic sonotrode.

[0037] According to a further embodiment of the invention, a counter-element can be arranged on the other side of the profile strip, in particular without offset in the longitudinal direction of the profile strip (directly) opposite the force transmission element. In particular, this counter-element is a preferably rubberized roller that presses against the profile strip, so that the profile strip is arranged, in particular clamped, between the force transmission element and the counter-element for transmitting the compressive forces. The counter-element can also be motor-driven and, for example, transmit additional compressive forces to the profile strip and / or decelerate the profile strip and / or the film web.

[0038] Downstream of the welding station, the device can also have conveying elements, in particular pulling rollers, with which the profile strip and the film web can be conveyed along the welding station by applying pulling forces, wherein the force transmission element is designed such that the compressive forces which it transmits to the profile strip are applied in the conveying direction.

[0039] Further features of the present invention will become apparent from the appended claims, the following description of preferred embodiments, and the accompanying drawings, in which: Fig. 1 shows a welding station of a bag packer operating according to the method according to the invention in an oblique view, partly in section, Fig. 2 shows the welding station of the bag packer according to the invention in a side view, partly in section, Fig. 3 shows a sectional view of the welding station along the section line III-III in Fig. 2, Fig. 4 a sectional view of the welding station along the section line IV-IV in Fig. 3 , Fig. 5 a sectional view of the welding station along the section line VV in Fig. 4 , Fig. 6 a sectional view of the welding station along the section line VI-VI in Fig. 4 , Fig. 7 a sectional view of the welding station along the section line VII-VII in Fig. 4 , Fig. 8 a sectional view of the welding station along the section line VIII-VIII in Fig. 7 , Fig. 9 a schematic representation of a control or regulation concept for the welding station or the bag packer according to the invention.

[0040] The drawings show a section of a bag packer for producing bags from film, in this case tobacco pouches, namely primarily a welding station 24 for welding a multi-action, i.e., multiply openable and closable, pressure seal 15 to a film web 10. Such a bag packer can otherwise be constructed as in the German patent application DE 10 2009 008 129 A1, the content of which is hereby incorporated into the present application for the purpose of sufficient disclosure.

[0041] One or more tobacco portions can be filled into a bag produced with the bag packer (not shown). Such a bag consists of a thin packaging material, in particular a (plastic) film that can be sealed or welded using ultrasonic and / or heat.

[0042] As shown in the present embodiment, such a bag can be produced from a continuous film web 10. The process is shown in simplified form as follows: In a manner already known, the initially flat, continuous film web 10 of the welding station 24 is folded by means of a folding device 16 to form a continuous edge 11 and is fed in this state to the welding station 24. In the present case, the folding device 16 comprises a folding triangle 17 and, downstream of this, two spaced-apart guide rollers 25a with parallel axes of rotation running perpendicular to the conveying direction of the film web 10, which enclose a guide gap. The film web 10 runs through this guide gap in the already folded state.

[0043] In the later bags, the edge 11 forms one or the bottom edge at which a front wall and a rear wall of the respective bag, which runs at an angle to the front wall, adjoin each other.

[0044] In the present exemplary embodiment, the respective front wall of the respective bag is formed by a front film web section 12, the rear wall and a cover flap of the bag by a rear film web section 13, cf. Fig. 1 .

[0045] With respect to the conveying direction of the film web 10, a pressure seal 15 (in this case a Zip-Lock®) is conveyed upstream of the welding station 24 as a continuous material web or as a continuous material strip in a closed state into the conveying path of the film web 10. The pressure seal 15 is formed by two detachably connectable, continuous profile strips 14a and 14b and is conveyed into the conveying path in a closed state, i.e., in a state in which the profile strips 14a and 14b are connected to one another. At the welding station 24, the profile strips 14a and 14b are then each welded to the film web 10 in a manner described in more detail below, namely, in this case, the profile strip 14a to the front film web section 12 and the profile strip 14b to the rear film web section 13.

[0046] Downstream of the welding station 24, opposite end sections of the profile strips 14a, 14b are fused ("crashed") together at a second welding station (not shown).

[0047] At a third sealing station (also not shown), transverse seams are produced, namely seams that run perpendicular to the bottom edge 11 and which, in the case of the later individual bags, form the lateral edges of the respective bag by connecting the front film web section 12 and the rear film web section 13.

[0048] Separating cuts are then made in the middle of these transverse seams in a separating station (not shown), so that the remaining transverse seam strips then form the side seams connecting the respective front and back walls of the finished bags.

[0049] The following describes in detail the particularly important features and method steps according to the invention that are related to the welding of the pressure seal 15 to the film web 10 at the welding station 24: To prepare for the welding processes at the welding station 24, the profile strips 14a, 14b are first separated from one another or the pressure seal 15 is opened. Alternatively, it is also conceivable that the profile strips 14a, 14b are connected to the film web cuts 12 and 13, respectively, while the pressure seal 15 is closed.

[0050] For separation or opening, the pressure closure 15 is conveyed along a separating switch 18 arranged in its conveying path, which separates the closed pressure closure 15 into the two separate profile strips 14a and 14b or releases the connection between the two profile strips 14a and 14b.

[0051] For this purpose, the separating switch 18 has a first, wedge-shaped free end 18a. The free end 18a engages centrally between the interconnected profile strips 14a, 14b and separates them into the individual profile strips 14a, 14b.

[0052] The separating switch 18 has an overall elongated contour. Downstream of the free end 18a, the separating switch 18 has lateral contact surfaces 19a, 19b on two opposite longitudinal sides. The front film web section 12 is conveyed together with the profile strip 14a along the front lateral contact surface 19a, while the rear film web section 13 is conveyed together with the profile strip 14b along the rear lateral contact surface 19b.

[0053] The profile strips 14a, 14b are guided, at least in sections, along guide grooves 20a, 20b recessed into the lateral contact surfaces 19a, 19b. These extend from the first free end 18a of the separating switch 18 along the lateral contact surfaces 19a and 19b of the separating switch 18 to a second wedge-shaped free end 18b of the separating switch 18.

[0054] Following the welding processes explained in more detail below, the pressure closure 15 is (re)closed, or the profile strips 14a, 14b are reconnected. For this purpose, the profile strips 14a, 14b are guided along the contact surfaces 19a and 19b of the second wedge-like end 18b, which converge in a wedge shape in the conveying direction, so that they are moved toward one another and finally pressed together by a pair of opposing guide rollers 25b, between which a guide gap is formed, with a correspondingly adapted dimension, through which the pressure closure 15 or the not yet fully reconnected profile strips 14a and 14b are guided.

[0055] The lateral contact surfaces 19a and 19b of the separating switch 18 are each interrupted by receiving areas 26a and 26b, respectively, in which a force transmission element 21a and 21b and a contact means 22a and 22b (anvil) are arranged one after the other in the conveying direction.

[0056] The respective contact means 22a or 22b is located opposite a welding element 23a or 23b arranged on the other side of the film web 10 or the respective profile strip 14a or 14b, namely in the present case an ultrasonic sonotrode, and is designed in the present case as a contact roller, driven in particular in a rotating manner (by a motor), with individual contact surfaces 27 arranged distributed over the circumference.

[0057] In this case, it can be provided that the contact means 22a, 22b have (internal) cooling, particularly for cooling the respective contact surface(s) 19a, 19b, based in particular on the passage of coolant. In the simplest case, this can, for example, comprise a cooling water channel 29 running inside the contact means 22a, 22b, through which cooling water or coolant is conducted.

[0058] The respective profile strip 14a or 14b is welded to the front film web section 12 or the rear film web section 13 by the respective welding element 23a, 23b. For this purpose, the respective welding element 23a or 23b can be moved perpendicular to the conveying direction of the film web 10 or the profile strip 14a or 14b from a rest position, in which it is spaced from the film web 10, towards the film web 10 into a welding position in which it presses the film web 10 (the front or rear film web sections 12 or 13, respectively) together with the profile strip 14a or 14b against the contact means 22a or 22b, namely against a contact surface 27 thereof, and welds the film web 10 to the respective profile strip 14a or 14b.

[0059] In this case, the respective film web section 12 or 13 on the one hand and the respective profile strip section 14a or 14b each abut each other, while the respective profile strip 14a or 14b is arranged in the respective guide groove 20a or 20b and the respective film web section 12 or 13 together with the associated profile strip 14a or 14b is arranged between the respective welding element 23a or 23b on the one hand and the contact means 22a or 22b on the other hand, see also Fig. 2 .

[0060] After welding the profile strips 14a, 14b to the film web 10, wrinkles often subsequently form in the welded area of ​​the film web 10. As already explained above, this is primarily due to the fact that the film web 10 and the pressure strip 15 or the profile strips 14a, 14b are generally conveyed along the welding station 24 by means of tensile forces. For example, by means of tensile forces exerted by tension rollers 41 arranged downstream of the welding station 24 (see FIG. Fig. 9 , along which the film web 10 and the pressure seal 15 are guided or which pull them accordingly along the welding station 24.

[0061] Due to the material, the profile strips 14a, 14b on the one hand and the film web 10 on the other hand expand differently and then contract differently once the tensile forces are removed. This effect is reinforced or supplemented by the fact that the profile strips 14a, 14b and the film web are initially expanded during welding due to the associated heating and then contract again upon cooling - also differently depending on the material.

[0062] To counteract this wrinkling, the force transmission elements 21a and 21b each introduce additional compressive forces into the profile strips 14a and 14b, respectively, to counteract this wrinkling. For this purpose, the force transmission elements 21a, 21b are each designed as a rotating (motor-driven) force transmission roller, each of which has serrated force transmission elements 28 distributed around the circumference in a force transmission area. These force transmission elements 28 each engage the respective profile strip 14a, 14b to transmit the compressive forces.

[0063] In order to optimise the force transmission, a counter-element 38 is arranged on the other side of the respective profile strip 14a, 14b, in particular a roller which presses against the profile strip 14a, 14b, so that the profile strip 14a, 14b is arranged, in particular clamped, between the force transmission element 21a or 21b and the respective counter-element 38 for transmitting the compressive forces.

[0064] In the present case, the direction of rotation of the force transmission elements 21a and 21b is selected such that the direction of the compressive forces they transmit corresponds to the conveying direction in which the profile strips 14a, 14b are conveyed when they are in the welding station 24 or are conveyed along the welding station 24.

[0065] The circumferential speed of the respective force transmission element 21a and 21b is selected to be greater than the conveying speed at which the film web 10 is conveyed or greater than the conveying speed at which the profile strips 21a and 21b are conveyed solely by the tensile forces of the tension rollers 41. This circumferential speed is preferably 10% to 50% greater, particularly preferably 30%.

[0066] In order to prevent lateral buckling of the respective profile strips 14a, 14b during this transmission of the compressive forces, i.e. an undesired movement perpendicular to the conveying direction of the profile strips 14a, 14b, guide means are provided.

[0067] In the conveying direction of the respective profile strip 14a, 14b, between the respective force transmission element 21a, 21b and the respective support element 22a, 22b, a guide element 30 is arranged, which prevents such buckling inward or toward the separating switch 18. The guide element 30 is arranged on the side of the respective profile strip 14a, 14b on which the force transmission element 21a, 21b and the support element 22a, 22b are also arranged. In the present case, the guide element 30 can, for example, be a guide rail with a guide surface running parallel to the profile strip 14a, 14b.

[0068] A buckling of the respective profile strip 14a, 14b in the opposite direction (outwards or away from the separating switch 18) caused by the compressive forces can be prevented by a further guide means 31, cf. Fig. 4, be prevented by being arranged on the corresponding other side of the respective profile strip 14a, 14b, namely on the side on which the respective welding element 23a, 23b is located. This can be, for example, a guide roller or a guide wheel.

[0069] In Fig. 9 Finally, a schematic diagram is shown of how the individual units of the welding station and bag packer could be controlled. In addition, some alternative or additional developments of the invention are presented.

[0070] It is shown how, by means of a central control 33, certain elements of the welding station 24 can be operated depending on one or more (current or actual) parameters that are measured.

[0071] For example, the temperature of the respective profile strip 14a, 14b could be measured with a temperature sensor 34 and / or the temperature of the film web with a temperature sensor 35 and / or the room temperature with a temperature sensor 36 and / or the temperature of the welding element 23a, 23b with a temperature sensor 37 and / or the temperature of the coolant of the (internal) cooling of the installation means 22a, 22b with a temperature sensor 45.

[0072] It is then conceivable, for example, to automatically control / regulate the rotational speed or speed of the respective power transmission element 21a, 21b (or of a drive motor 32 driving it) or the rotational speed of the respective power transmission element 21a, 21b and thus the strength of the compressive forces introduced into the respective profile strips 14a, 14b depending on one or more of these parameters, preferably depending on the temperature of the respective profile strip 14a, 14b, and / or the temperature of the film web 10 and / or the room temperature.

[0073] It is also conceivable to automatically control / regulate the speed of the film web 10 and / or the tensile forces with which the film web 10 is conveyed along the welding station (via a motor 39 which drives the tension rollers 41) depending on one or more of the aforementioned parameters.

[0074] It is also conceivable to control / regulate the rotational speed or speed of rotation of the respective installation means 22a, 22b (or of a drive motor 40 driving it) or the rotational speed of the respective installation means 22a, 22b depending on one or more of these parameters.

[0075] Furthermore, the speed of a coolant pump 42 conveying the coolant for the (internal) cooling of the system means 22a, 22b could also be controlled / regulated depending on one or more of these aforementioned parameters, preferably depending on the coolant temperature.

[0076] Furthermore, the power of a compressed air nozzle for cooling the respective welding element 23a or 23b could be controlled / regulated depending on one or more of the aforementioned parameters (or the power of a compressed air source 44 that supplies compressed air to the compressed air nozzle 43), preferably depending on the temperature of the welding element 23a, 23b.

[0077] Furthermore, depending on one or more of the aforementioned parameters, the pressure in a pneumatic cylinder 46 could also be controlled / regulated, which can transfer the respective welding element 23a, 23b from a rest position to a welding position (and back) and which presses the welding element 23a, 23b in the welding position against the film web 10. If the welding element 23a, 23b lowers during the welding process due to the yielding of the film web 10, the welding force can be kept constant by appropriate control / regulation of the pneumatic cylinder 26. List of reference symbols: 10 film web 26b Recording area 11 edge 27 Investment areas Investment funds 12 front film web section 28 Power transmission elements 13 rear film web section 29 Cooling water channel 14a Profile strips 30 Management tools 14b Profile strips 31 Management tools 15 snap fastener 32 drive motor 16 Folding device 33 central control 17 folding triangle 34 Temperature sensor 18 Separating switch 35 Temperature sensor 18a first free end 36 Temperature sensor 18b second free end 37 Temperature sensor 19a contact surface 38 Counter organ 19b contact surface 39 drive motor 20a guide groove 40 drive motor 20b guide groove 41 Pulleys 21a Power transmission element 42 coolant pump 21b Power transmission element 43 pressure nozzle 22a Investment funds 44 Compressed air source 22b Investment funds 45 Temperature sensor 23a sweat organ 46 Pneumatic cylinder 23b sweat organ 24 welding station 25a leadership roles 25b leadership roles 26a Recording area

Claims

1. Method for manufacturing foil bags, preferably tobacco bags, in which a foil web (10) is welded, in particular ultrasonically, at a welding station (24), to at least one of two profile strips, which can be releasably connected to one another, of a multi-action pressure closure (15), preferably while the foil web (10) and the profile strip are being continuously conveyed along the welding station (24), wherein the profile strip is subjected, during the welding operation, to compressive forces, which act in the longitudinal direction of said profile strip and counteract creasing of the foil web (10), wherein the compressive forces are applied to the profile strip by means of a force-transmission member (21a, 21b) acting on the profile strip, wherein, in the region of the welding station (24), the profile strip is guided laterally by a guide means in order to prevent lateral buckling, caused by the compressive forces, of the profile strip, wherein the foil web (10) is pressed against a contact means (22a, 22b) opposite the welding member during the welding process, with the profile strip being carried along by a welding member (23a, 23b) arranged downstream of the force-transmission member (21a, 21b), wherein the contact means (22a, 22b) faces the same side of the profile strip as the force-transmission member (21a, 21b), characterized in that the guide means, in particular a guide roller or a guide rail, is arranged with respect to the longitudinal direction or conveying direction of the profile strip between the force-transmission member (21a, 21b) and the contact means (22a, 22b), preferably in such a manner that it faces the same side of the profile strip as the force-transmission member (21a, 21b) and the contact means (22a, 22b).

2. Method according to Claim 1, characterized in that the force-transmission member (21a, 21b) is a force-transmission member (21a, 21b) that faces one side of the profile strip, in particular a force-transmission roller, in particular a force-transmission member (21a, 21b) that has one or more, preferably serrated, force-transmission elements, which act on the profile strip, in particular on one side of the profile strip, in order to transmit the compressive forces.

3. Method according to one or more of the preceding claims, characterized in that the guide means faces one side of the profile strip.

4. Method according to one or more of the preceding claims, at least according to Claim 2, characterized in that the foil web (10) and the profile strip are subjected to tensile forces generated in particular by conveying members, preferably tension rollers, in order to convey the foil web (10) and the profile strip in a conveying direction along the welding station (24), wherein the compressive forces are applied in addition to the tensile forces, preferably in the conveying direction of the profile strip, in particular compressive forces that are greater than the tensile forces, and / or in that the contact means is a rotatably driven contact roller, preferably a contact roller having a slower rotational speed than the rotational speed of the force-transmission roller.

5. Method according to Claims 3 and 4, characterized in that the profile strip is laterally guided by a further guide means, wherein one guide means faces one side of the profile strip and the other guide means faces the other side of the profile strip.

6. Method according to one or more of the preceding claims, characterized in that the speed component of the force-transmission member (21a, 21b), which is active when the compressive forces are being transmitted to the profile strip, in particular the peripheral speed of the force-transmission roller, is 10% to 50% greater, preferably 30% greater, than the speed at which the foil web (10) is moved, and / or in that the speed component of the force-transmission member (21a, 22b), which is active when the compressive forces are being transmitted to the profile strip, in particular the peripheral speed of the force-transmission roller, is subject to open-loop or closed-loop control according to the speed, temperature and / or the material type of the foil of the foil web (10) and / or of the profile strip, in particular in such a manner that, for a plurality of speed values, temperature values and / or material-type values of the foil of the foil web (10) and / or of the profile strip, an assigned setpoint value for the speed component is stored in each case in a memory, in particular in a table, wherein, in order to subject the force-transmission member (21a, 21b) to open-loop or closed-loop control, this setpoint value is selected according to the respective actual value of the speed, the temperature and / or material type of the foil of the foil web (10) and / or of the profile strip.

7. Method according to one or more of the preceding claims, characterized in that the temperature of the foil, the temperature of the profile strip, the temperature of the welding member and / or the temperature of the contact means (22a, 22b) (in operation) is measured, and in that, in dependence thereon, the speed component of the force-transmission member, which is active when the compressive forces are being transmitted to the profile strip, and / or the power of the welding member are / is subject to closed-loop control.

8. Method according to one or more of the preceding claims, characterized in that, after the welding process, in particular downstream of the welding station (24), the foil web (10) is monitored with respect to the creasing of the foil web (10) using a checking member, in particular an electro-optical checking member, preferably a line sensor, and in that the speed component of the force-transmission member (21a, 21b), which is active when the compressive forces are being transmitted to the profile strip, and / or the power of the welding member (23a, 23b) are / is automatically changed, in particular are / is subject to closed-loop control, in order to counteract creasing, should the checking member detect any creasing or creasing that exceeds a predetermined level.

9. Method according to one or more of the preceding claims, characterized in that the second profile strip of the pressure closure is likewise subjected, during the welding operation, to compressive forces, which act in the longitudinal direction and counteract creasing of the foil web (10), in particular according to one or more further features of one or more of the preceding claims.

10. Apparatus for manufacturing foil bags, preferably tobacco bags, in particular for carrying out the method according to one or more of preceding Claims 1-9, having a welding station (24), at which a foil web (10) can be welded to at least one of two profile strips, which can be releasably connected to one another, of a multi-action pressure closure (15) using a welding member (23a, 23b), in particular an ultrasonic welding member, which is preferably designed as an ultrasonic sonotrode that moves in rotation or in translation, wherein the apparatus has a force-transmission member (21a, 21b), in particular a rotationally driven force-transmission roller, which can be used to introduce compressive forces, which act in the longitudinal direction of said profile strip and counteract creasing of the foil web (10), into the profile strip during the welding process, and wherein the apparatus, in particular the welding station (24), has a guide means, which guides the profile strip on at least one side in order to prevent lateral buckling, caused by the compressive forces, of the profile strip, wherein the welding station (24) has a contact means (22a, 22b), in particular a rotatable contact roller, arranged opposite the welding member (23a, 23b), wherein the contact means (22a, 22b) faces the same side of the profile strip as the force-transmission member (21a, 21b) and is arranged downstream thereof, wherein the foil web (10) and the profile strip are guided between the welding member (23a, 23b) and the contact means (22a, 22b), and wherein the foil web (10) and the profile strip can be jointly pressed against the contact means (22a, 22b) by the welding member (23a, 23b) during the welding process, characterized in that the guide means, in particular a guide roller or a guide rail, is arranged between the force-transmission member (21a, 21b) and the contact means (22a, 22b), preferably in such a manner that it faces the same side of the profile strip as the force-transmission member (21a, 21b) and the contact means (22a, 22b).

11. Apparatus according to Claim 10, characterized in that the force-transmission member (21a, 21b), in particular the force-transmission roller, has one or more, preferably serrated, force-transmission elements, which act on the profile strip in order to transmit the compressive forces, in particular on one side of the profile strip, and / or in that the guide means faces one side of the profile strip.

12. Apparatus according to Claim 11, characterized in that the contact means (22a, 22b) is a rotatable, preferably motor-driven, preferably individual, separate contact roller, which has contact surfaces distributed over the circumference.

13. Apparatus according to one or more of preceding Claims 10-12, characterized in that the apparatus, in particular the welding station (24), has a further guide means, which laterally guides the profile strip in order to prevent lateral buckling, caused by the compressive forces, of the profile strip, wherein one guide means faces one side of the profile strip and provides guidance there, and wherein the other guide means faces the other side of the profile strip and provides guidance there.

14. Apparatus according to one or more of preceding Claims 12-13, at least according to Claim 12, characterized in that the contact means (22a, 22b) has (internal) cooling, in particular for cooling the contact surface(s), preferably electrically powered cooling or cooling based on the use of cooling liquids.

15. Apparatus according to one or more of preceding Claims 10-14, characterized in that, on the other side of the profile strip, in particular without offset in the longitudinal direction of the profile strip, a counter-member (38), in particular a roller that presses against the profile strip, is arranged (directly) opposite the force-transmission member (21a, 21b), so that the profile strip is arranged, in particular is clamped, between the force-transmission member (21a, 21b) and the counter-member (38) in order to transmit the compressive forces.

16. Apparatus according to one or more of preceding Claims 10-15, characterized in that the apparatus downstream of the welding station (24) has conveying members, in particular tension rollers, which can be used to convey the profile strip and the foil web (10) along the welding station (24) with application of tensile forces, and in that the force-transmission member (21a, 21b) is designed in such a manner that the compressive forces it transmits to the profile strip are applied in the conveying direction.