Sealing of cut edges of hollow articles that are open at both ends

Abstract

The invention relates to a method and a device for sealing cut edges of hollow articles that are open at both ends and comprise a cover on the exterior of the hollow article.

Description

[0001] SEALING CUT EDGES OF HOLLOW BODIES OPEN ON BOTH SIDES

[0002] The invention relates to a method and a device for sealing cut edges of hollow bodies open on both sides with a shell present on the outside of the hollow body.

[0003] The hollow body, open on both sides, can be provided with a closure element at each end to form a can and contain a medium as its contents. The closure elements are in the form of a base and a lid, as is known from cans, for example, beverage cans in the form of aluminum cans or composite cans.

[0004] The hollow body, open on both sides, is designed as a section of a continuous tube consisting of several layers, with the innermost layer being a dense barrier layer. At least one further layer of the hollow body consists of a non-liquid-tight material, particularly paper, cardboard, or paperboard. The barrier layer prevents liquid or moisture from the interior of the hollow body from penetrating the next layer.

[0005] When the hollow body, which is open on both sides, is cut, the two cut edges of the further layer are exposed.

[0006] The application of sleeves to packaging bodies, especially plastic containers such as PET bottles, is well known in the art. This involves pulling an expandable sleeve over the packaging body and adhering to the outer surface of the packaging body. Depending on the application principle, a distinction is made between shrink sleeves and stretch sleeves. Shrink sleeves are shrunk onto the packaging body under the influence of heat, while stretch sleeves contract and adhere to the outer surface solely due to their elastic properties.

[0007] From WO2022219176A1, the applicant discloses a can and a method for producing a can, in which, in one embodiment, the cut edges of the can are sealed by a sleeve that is pulled over the hollow body, which is open on both sides and is in the form of the can shell. WO2022219176A1 already discloses that the sleeve can be in the form of an expandable sleeve and that the sleeve can be folded inward and connected to the inner barrier layer of the hollow body. Furthermore, it is disclosed that the hollow body can already have outwardly shaped end regions. A shaped end region is understood to mean a radial shape of the shell at the open end of the hollow body.

[0008] An object of the invention is to provide a method and a device to be able to apply the sleeve to the inside of the hollow body, in particular in a continuous process.

[0009] To solve this problem, one embodiment proposes a method for attaching an outer shell to the inside of a hollow body open on both sides. To solve this problem, one embodiment proposes a device for attaching an outer shell to the inside of a hollow body open on both sides.

[0010] In one embodiment of a method according to the invention, an expandable sleeve is attached to the hollow body in a first step, extending beyond the hollow body on both sides. The hollow body preferably already has formed edges. This refers to an outwardly deformed edge region, in particular an end region extending outward along a radius.

[0011] As a machine for placing the sleeve on the hollow body, a known device of the prior art for attaching sleeves to packaging bodies can be used, in particular a device for attaching stretch sleeves.

[0012] Compared to the known method, however, there is the difference that the sleeve is attached to a hollow body that is open on both sides and the sleeve is longer than the hollow body, so that the sleeve projects beyond both cut edges of the hollow body.

[0013] Due to this overlap and the use of an elastic film as the material for the cover, which contracts after application, the overlapping edges of the cover protrude into the respective opening at an angle or approximately at right angles to the outer surface of the hollow body. This result of the first step thus differs from the state of the art.

[0014] The second step of the inventive method consists in pressing the inwardly projecting portion of the casing against the barrier layer at the cut edges of the hollow body, which is open on both sides, and sealingly bonding it to the barrier layer. This is preferably done by welding the casing to the barrier layer using heat.

[0015] The heat effect can be caused by a heated or heated surface of a body, which presses the inwardly projecting areas of the casing against the barrier layer.

[0016] In one embodiment, the heat can be applied using hot air. In another embodiment, the heat can be applied using hot compressed air, with the compressed air pressing the inwardly projecting portions of the casing against the barrier layer.

[0017] In other versions, the heat can be applied by ultrasound or induction. In other versions, the heat can be applied by laser. In another version, the heat can be applied by thermal radiation. In another version, the heat can be applied by infrared light.

[0018] If the welding is carried out or assisted by a laser, it is preferably provided that the sleeve is pressed against the barrier layer by a transparent pressing element, in particular a transparent stamp, wherein at least one laser beam passes through the transparent pressing element to the area to be welded. The welding methods mentioned can each be used on one or both sides of the hollow body. Several methods can also be used in combination, wherein two or more energy sources can act simultaneously or a first energy source is used first and then a different second energy source. Thus, an initial pre-welding can be carried out with the first energy source and the welding can then be completed with a second energy source.In one embodiment, the two welding steps differ in the type, level or presence of a counterpressure on the outside of the hollow body and / or in the type or presence of a pressure element on the inside of the hollow body, or its contact pressure.

[0019] In another embodiment, an adhesive can be used to bond the sleeve to the barrier layer. The adhesive can be applied to the inwardly projecting portion of the sleeve or to the barrier layer.

[0020] In one embodiment, the adhesive can be heat-activated. In another embodiment, the adhesive can be light-activated, particularly UV-activated.

[0021] The attachment of the inwardly projecting areas of the shell to the inside of the barrier layer can be carried out in an identical manner at both ends of the hollow body or by different methods selected from the methods mentioned herein.

[0022] In one embodiment, the shell or hollow body is heated before the shell is attached to the barrier layer. In one embodiment, the shell and hollow body are heated before the shell is attached to the barrier layer. The heating takes place or begins before the inwardly projecting portion of the shell is pressed against the barrier layer of the hollow body.

[0023] It is preferred that the inwardly projecting portions of the sleeve be joined to the barrier layer at the sleeve placement system or subsequently. In known sleeve placement systems, the packaging bodies are continuously moved along a line and / or through a carousel. A mechanical device for stretching and covering the sleeve can be moved along with the packaging bodies over a portion of the area.

[0024] Preferably, the machine for placing the sleeve is followed by a station according to the invention for connecting the projecting areas of the sleeve to the barrier layer. Preferably, the two projecting areas are simultaneously pressed against the opposite openings of the hollow body or connected to the barrier layer. In another embodiment, the two opposite openings are processed one after the other. In this case, it is possible for the hollow body to be turned over after the sleeve and the barrier layer have been connected on the first side, or for the hollow body to be transferred from a first holder to a second holder. In a further embodiment, it is provided that after the sleeve and the barrier layer have been connected on the first side, a first closure element is attached to this first side and then the sleeve and the barrier layer are connected on the second side.The first closure element applied can be the bottom or the lid of a can.

[0025] After the shell and barrier layer have been bonded on the second side, the hollow body, now sealed on one side, can be filled, and a second closure element can then be applied to the second side. The shell and barrier layer can be bonded on the second side simultaneously or overlapping the filling process.

[0026] Filling can take place immediately after the station for closing the first end of the hollow body at the same location. Alternatively, the hollow bodies can be transported to a filling line after sealing the two cut edges or after closing the first open end.

[0027] One or each of the two closure elements can be attached to the hollow body in the preheated state.

[0028] Preferably, the inwardly projecting regions of the casing are pressed against the barrier layer by a pressing element which is moved perpendicularly towards the opening surface until it rests on the inside against the outwardly shaped edge region of the hollow body.

[0029] During this time, the hollow body is preferably held externally directly beneath the molding by a retaining element. This retaining element creates the necessary counterpressure on the outside of the molding to prevent it from being deformed or damaged when the pressure element is applied.

[0030] Preferably, a retaining element is provided at each end of the hollow body. Alternatively, a retaining element can be provided that extends over the entire height of the hollow body in order to apply counterpressure to both outwardly shaped hollow body edges.

[0031] The retaining element can be made of a dimensionally stable material such as metal or plastic. In one embodiment, the retaining element has an elastic surface, particularly made of rubber, silicone, or another elastic material.

[0032] In one embodiment, the retaining element comprises an inflatable or inflatable body or an otherwise expandable body that rests against the hollow body, in particular its molded hollow body edge. The inflatable or inflatable body can be a ring that, in the non-expanded state, can be moved externally over the molded hollow body edge, with the expansion causing a reduction in the inner diameter of the ring.

[0033] In another embodiment, the hollow body is held internally. The hollow body is preferably held with a defined position of the side seam of the shell and / or a thickness increase in the casing of the hollow body. In one embodiment, a holding element on the outside of the hollow body can have a recess for the side seam of the shell and / or a recess for receiving a thickness increase of the hollow body present on the outside of the casing. In one embodiment, a holding element on the inside of the hollow body can have a recess for a thickness increase of the hollow body present on the inside of the casing. In one embodiment, a pressing element, which presses the inwardly projecting region of the shell against the barrier layer, can have a recess for receiving the side seam of the shell and / or a recess for receiving a thickness increase of the casing.

[0034] Preferably, the system comprises a carousel or a line, wherein several pressing units comprising pressing elements and holding elements move along with the hollow bodies moved along the carousel or the line.

[0035] In one embodiment, the hollow bodies can also be stationary while the casing is pressed against the shell by the pressing elements, with several pressing elements preferably being pressed against several stationary hollow bodies simultaneously. This can be achieved by stopping the conveyor device for the hollow bodies for this process, or by removing the hollow bodies for this process from a continuously moving conveyor device and returning them to the continuously moving conveyor device after the process.

[0036] This process with stationary hollow bodies that are processed in groups can be described as a batch process.

[0037] In another design variant, the inward-projecting areas of the sleeve are only connected to the barrier layer when closure elements are placed. The closure elements are preferably in the form of a can lid and can base. When a closure element is placed, the edge area of ​​the closure element is placed on the outwardly shaped hollow body edge and the two edge areas are crimped together. By crimping, the edge area of ​​the closure element and the edge area of ​​the hollow body are mechanically pressed together to create a tight connection. By mechanical pressing, the inward-projecting area of ​​the sleeve is pressed against the barrier layer. In one design variant, only this mechanical connection of the sleeve to the barrier layer is created by crimping the closure element.

[0038] In variant designs, one or each of the two closure elements can be attached to the hollow body in the preheated state.

[0039] In another design variant, the sleeve is additionally welded to the barrier layer. This can be achieved by attaching a heated closure element or by subsequent heat exposure, for example, through ultrasound, induction, thermal radiation, hot air, or laser. If the closure element has a plastic coating on the inside, this can also be welded to the sleeve.

[0040] One embodiment of the invention consists in a method for attaching a sleeve to the outside of a hollow body open on both sides, wherein the hollow body is held on its inside when the sleeve is attached, wherein the sleeve is longer than the hollow body and projects beyond the hollow body at both ends of the hollow body after attachment.

[0041] One embodiment of the invention consists in a device for attaching a sleeve to the outside of a hollow body open on both sides, wherein a holding device projects into the inside of the hollow body and rests against the inside of the hollow body, wherein the hollow body is present at a defined longitudinal position and with a defined orientation on the holding device.

[0042] One embodiment of the invention consists in a method in which, in a first step, a sleeve is attached to the outside of a hollow body open on both sides. After attachment, the sleeve projects beyond the hollow body at both ends. In a second step, the projecting portions of the sleeve are attached to the inside of the hollow body. The first step can be carried out using known methods and devices of the prior art.

[0043] One embodiment relates to a method for placing an elastic sleeve on each hollow body that is open on both sides, which sleeve is longer than the distance between the two opposite open ends of the hollow body and which sleeve, in the unexpanded state, has a smaller circumference than the hollow body at its open ends, wherein the hollow bodies that are open on both sides are held in a machine for applying the sleeve from the inside, wherein the respective sleeve is expanded at least at its end facing the hollow body by means of a spreading effect and is placed over the respective hollow body in the longitudinal direction of the hollow body until the sleeve projects beyond the lateral surface of the hollow body at both open ends in the longitudinal direction of the hollow body, wherein the spreading effect is subsequently removed, whereupon the two edges of the sleeve that project beyond the hollow body project obliquely or vertically inwards from the opening edge of the hollow body,whereby the two inwardly projecting edges of the shell are subsequently pressed against the inner surface of the hollow body and connected to it.

[0044] In this method, it is preferred that the respective hollow body is cylindrical and has an outwardly shaped edge region at both open ends, in particular two opposite edge regions extending outwards along a radius, between which a cylindrical shell section of the hollow body extends.

[0045] In this method, it is preferred that the inner surface of the respective hollow body is formed by a barrier material which extends over the entire height of the hollow body up to the two opening edges, and that the outer surface of the hollow body is made of paper or cardboard. In this method, it is preferred that a plurality of hollow bodies are moved simultaneously through the machine for applying the sleeves, with each hollow body being present on a holding element which rests on the inside against the surface of the hollow body. After the sleeve has been applied, the hollow bodies are transported further on the holding element to a device which presses one or both of the inwardly projecting edges of the sleeve against the inner surface of the hollow body.

[0046] In this method, it is preferred that before or when the inwardly projecting edges of the casing are pressed against the inner surface of the hollow body, heat is applied to the casing and the inner surface of the respective hollow body, wherein the casing and the inner surface are formed from plastic and are welded together.

[0047] In one embodiment of the method, it is provided that the pressing of at least one of the two inwardly projecting edges of the casing is carried out by attaching a closure element which closes an opening of the hollow body.

[0048] It is preferred that the respective hollow body is supported from the inside by a holding element on its entire cylindrical inner shell region when the shell is attached.

[0049] It is preferred that the respective hollow body is supported from the inside by a holding element when attaching the cover to at least one outwardly shaped edge region of the hollow body.

[0050] In this method, it is preferred that the expansion of the sleeve is carried out by a plurality of expansion elements which project into the interior of the sleeve, wherein the expansion elements bear against the inside of the sleeve over a length of the sleeve which is at least half the length of the hollow body, wherein the plurality of expansion elements are present between the sleeve and the hollow body when the sleeve is placed and wherein these are pulled out between the hollow body and the sleeve when the sleeve is in the desired position on the hollow body.

[0051] In this method, it is preferred that when pressing and connecting at least one of the two inwardly projecting edges of the shell to the inner surface of the hollow body, a counterpressure is applied to the outside of the hollow body, in particular to an outwardly shaped edge region of the hollow body.

[0052] It is preferred that the counterpressure is provided by a holder which surrounds the hollow body.

[0053] It is preferred that the counterpressure is provided by an expandable, in particular inflatable or pumpable element, which only rests against the outer edge region of the hollow body in the expanded state.

[0054] It is preferred that the sleeve is attached to the hollow body with a controlled orientation, so that an increase in thickness of the shell of the hollow body and an increase in thickness of the sleeve are located at different circumferential regions. It is preferred that at least one of the two inwardly projecting edges of the sleeve is pressed against the inner surface of the hollow body using a transparent stamp, and a laser beam is directed through the transparent stamp onto the areas of the sleeve and the inner surface of the hollow body to be joined.

[0055] One embodiment relates to a device for attaching an outer sleeve to the inside of a hollow body that is open on both sides, the sleeve of the respective hollow body being placed outside over the hollow body, the sleeve projecting beyond the lateral surface of the hollow body at both open ends in the longitudinal direction of the hollow body, the two edges of the sleeve that project beyond the hollow body preferably projecting obliquely or perpendicularly inwards from the opening edge of the hollow body, the device comprising holding devices or holders for holding an open hollow body each, and the device comprising pressing elements for pressing the sleeve onto the inside of the hollow body at at least one end of the open hollow body, the device being able to carry out a relative movement between the pressing elements and the holding devices or holders.

[0056] It is preferred that the device comprises means for welding the shell to the inside of the hollow body which is open on both sides.

[0057] It is preferred that the device comprises means for applying a counterpressure on the outside of the hollow body relative to the pressing elements.

[0058] Preferably, the sleeve was placed on the hollow body according to the methods described herein before it reaches the said device for attaching an outer sleeve to the inside of each hollow body open on both sides.

[0059] Less preferably, the cover may also be placed in another way, as long as it envelops the hollow body on the outside and projects beyond it at both open ends.

[0060] The sleeve is preferably an expandable sleeve. Less preferably, it can also be a shrink sleeve.

[0061] The invention is further explained with reference to the following embodiments shown in the figures:

[0062] Fig. 1 schematically illustrates a device for attaching an outer shell to the inside of a hollow body open on both sides in the opened state.

[0063] Fig. 2 schematically illustrates a device for attaching an outer shell to the inside of a hollow body open on both sides in the closed state.

[0064] Fig. 3 schematically illustrates the process of receiving a hollow body open on both sides in a first exemplary holder. Fig. 4 schematically illustrates the process of inserting the first exemplary holder, with the hollow body open on both sides, into a casing.

[0065] Fig. 5 schematically illustrates the first exemplary holder with the hollow body open on both sides in the shell.

[0066] Fig. 6 schematically illustrates a device for attaching the sleeve to the inside of the hollow body comprising the first exemplary holder of Figs. 3 to 5.

[0067] Fig. 7 schematically illustrates the process of receiving a hollow body open on both sides in a second exemplary holder.

[0068] Fig. 8 schematically illustrates the combination of the second exemplary holder with a loose element before the introduction of the second exemplary holder with the hollow body open on both sides into a casing.

[0069] Fig. 9 schematically illustrates the process of inserting the second exemplary holder with the hollow body open on both sides into a casing.

[0070] Fig. 10 schematically illustrates the second exemplary holder with the hollow body open on both sides in the shell.

[0071] Fig. 11 schematically illustrates a device for fastening the sleeve to the inside of the hollow body comprising the second exemplary holder of Figs. 7 to 10.

[0072] Fig. 12 shows another variant for attaching the cover.

[0073] Fig. 13 and 14 illustrate internal supports of the hollow body when connecting the shell to the barrier layer.

[0074] Fig. 15 shows a variant for connecting the shell to the barrier layer by sealing the hollow body with a closure element.

[0075] Fig. 16 illustrates the offset arrangement of an increase in thickness of the shell of the hollow body and an increase in thickness of the casing.

[0076] The figures are not to scale and are schematic sketches.

[0077] The embodiments shown in the figures merely illustrate possible embodiments. It should be noted at this point that the invention is not limited to the specifically illustrated embodiments, but rather combinations of the individual embodiments with one another and a combination of an embodiment with the general description given above are also possible. These further possible combinations do not need to be mentioned explicitly, since these further possible combinations are within the skill of a person skilled in the art based on the teaching of technical action based on the invention in question. The scope of protection is determined by the claims. However, the description and the drawings must be used to interpret the claims.Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying the independent inventive solutions can be found in the description.

[0078] Big. 1 and 2 illustrate a device for attaching an outer shell 1 to the inside of a hollow body 2 open on both sides. The hollow body 2 comprises a multi-layer casing comprising at least one outer layer 3 made of absorbent and / or non-liquid-resistant material. Preferably, the hollow body 2 comprises several such outer layers 3.

[0079] On the inside, the hollow body 2 has a barrier layer 4, which is impermeable to liquid. The barrier layer 4 is particularly impermeable to the contents of the finished packaging body. The barrier layer 4 forms a closed inner wall of the hollow body 2.

[0080] To create hollow bodies 2, preferably, the multiple layers are first wound into a continuous tube. Subsequently, individual hollow bodies 2 are cut from the continuous tube, so that the outer layer 3 or the multiple outer layers 3 are exposed at the cut edges of the hollow bodies 2.

[0081] After separating the individual hollow bodies 2, their respective edge regions are shaped outward, i.e., provided with a radially outwardly extending edge region. The shape 5 is preferably in the form of a radius.

[0082] The outer layer 3 or the outermost of several layers 3 of the hollow body 2 can consist on the outside of absorbent and / or non-liquid-resistant material.

[0083] The outer layer 3 or each of several outer layers 3 is preferably made of cardboard, paperboard, or paper. Kraft paper is preferred.

[0084] In Figs. 1 and 2, a sleeve 1 is already present outside the hollow body 2. The sleeve 1 can be pulled over the hollow body 2 using a machine for applying stretch sleeves, or the hollow body can be pushed into the sleeve 1 using a machine for applying stretch sleeves. Such machines are generally known in the art.

[0085] However, the decisive feature of the present invention is that the casing 1 is longer than the hollow body 2, with the casing 1 projecting beyond both cut edges of the hollow body 2. Thus, there is a projecting area 6 of the casing 1 in each case.

[0086] This protruding area 6 is shown running perpendicular to the longitudinal direction of the hollow body 2, but it can also protrude obliquely inwards.

[0087] One function of the device is to press the protruding areas 6 inward against the barrier layer 4 and secure them there. One embodiment of a machine for securing the protruding areas of the casing 1 comprises at least one holder 7 for each hollow body 2 simultaneously moved through the machine. As shown, two holders 7 can be provided per hollow body 2, one for each end area.

[0088] In one embodiment, the holders 7 can initially be positioned centrally on the hollow body 2 and press the sleeve 1 centrally onto the hollow body 2. The holders 7 are then moved apart to the edges of the hollow body 2. This allows any air that may be located between the hollow body 2 and the sleeve 1 to be removed. Furthermore, the sleeve 1 adheres better to the hollow body 2 if the elastic restoring forces are insufficient. In a less preferred embodiment, the holders 7 can be heated to shrink the sleeve 1. However, a stretch sleeve is preferably used.

[0089] The holders 7 preferably encompass the circumference of the hollow body 2 at one of the end regions. As shown, the holders 7 can have radii shaped according to the recess 5. Alternatively, the holders 7 can also hold the hollow body 2 at a slight distance from the recess 5.

[0090] Preferably, each hollow body 2 is gripped by a holder 7 (or two holders 7) upon reaching the machine and then moved through the machine with this holder 7 (or these holders 7) until the hollow body 2 is removed from the machine or transferred to another machine.

[0091] As soon as the hollow body 2 is held in the holder 7, the two pressing elements 8 can be moved into the two open ends of the hollow body 2 so that they press the projecting areas 6 of the shell 1 against the barrier layer 4. Preferably, the projecting areas 6 rest exclusively on the formation 5 and thus do not extend to the vertical area of ​​the inner hollow body wall.

[0092] The pressing elements 8 preferably have a surface shape in the region of the recess 5 that corresponds to the shape of the recess 5. The surface shape can have a recess for a thickness increase 21 of the shell 1. The surface shape can have a recess for a thickness increase of the hollow body 2.

[0093] Since the pressing elements 8 and preferably also the holders 7 are designed according to the shape of the formation 5 facing them, the shape of the formation 5 is retained during the attachment of the projecting areas 6.

[0094] When the projecting areas 6 are connected to the barrier layer 4, in particular fused or glued, the pressing elements 8 can be moved out of the hollow body 2 and the hollow body 2 can be removed from the holders 7 or transferred from the holders 7 to another part of the system.

[0095] The pressing elements 8 are preferably moved through the machine together with the holders 7 and the hollow body 2. Instead of a pressing element 8, which simultaneously presses the protruding area 6 along its entire circumference, a less preferred rotating or pivoting pressing element can also be used, which presses the protruding area 6 from one or more locations along the entire circumference.

[0096] Preferably, many devices, each comprising one or two holders 7 and two pressing elements 8, are arranged on a carousel, wherein hollow bodies 2 are moved over a partial area of ​​the circumference of the carousel.

[0097] Less preferably, many devices, each comprising one or two holders 7 and two pressing elements 8, can be moved along a line and, as soon as a hollow body 2 has been released at the end of the line, can be moved back to the beginning of the line.

[0098] Less preferably, the holders 7 and the pressing elements 8 can be moved independently of each other with the hollow bodies 2.

[0099] Alternatively, several devices, each comprising one or two holders 7 and two pressing elements 8, can be arranged in a stationary manner on a transport line (carousel or line) for hollow bodies 2, wherein each device removes a hollow body 2 from the line at a time offset or simultaneously with the other devices and transfers it to another line after completion of the attachment.

[0100] Following the machine for applying the protruding areas 6, a machine for applying a closure element to one of the two ends of the hollow body 2 can follow. The closure element is preferably placed over the formation 5 and rolled up with it to form a bead. The formation 5 and thus also the protruding area 6 attached to the barrier layer 4 are enclosed in the bead of the closure element and also mechanically pressed by it. The hollow body 2 can then be filled from the still open side and subsequently closed on this side with a second closure element in the same way. Since at least the grommet of the hollow body and the placement of the second closure element take place in a humid environment, the protection of the cut edge by the sleeve 1 is important.

[0101] Following the machine for attaching the protruding areas 6 and / or after the placement of the first closure element, the hollow bodies 2 can also be stored temporarily until they are brought to the filling stage.

[0102] The cover 1 and / or the outermost layer 3 may have a print.

[0103] Figs. 3-11 do not directly address the core task of pressing the protruding areas 6, but these can be considered upstream steps of a preferred process or system. Fig. 3 shows a first variant of a holding device 9 for hollow bodies 2, which can be moved with the hollow bodies 2 through a machine for applying sleeves 1.

[0104] The holding device 9 can fulfill two functions. First, it can have a shape corresponding to the shape of objects previously provided with sleeves using known devices. Such objects, in particular bottles, have a conical upper region with which the object is pushed into the sleeve. Accordingly, the holding device 9 has an upper end that projects beyond the hollow body 2 at the time of insertion into the sleeve 1, which upper end comprises a tapered, in particular conical or rounded region. The expansion of the sleeve 1 is thus advantageously achieved by the holding device 9 and not by the shaping 5 of the hollow body 2.

[0105] The second task of the holding device 9 is to stabilize the hollow body 2 from the inside, particularly in the area of ​​the molding 5.

[0106] In one embodiment, the holding device 9 can be present as a packaging dummy, which means that instead of a known object, such as a bottle, a packaging dummy comprising the holding device 9 and the hollow body 2 attached thereto is moved through the system for applying the sleeve 1. The packaging dummy is received in a holder by the system like a conventional object to be packaged and moved through the system. The end result is a packaging dummy according to Fig. 5 or Fig. 10. If the holding device 9 is removed from the hollow body 2, the protruding areas 6 contract, so that the state of Fig. 1 is achieved, so that the protruding areas 6 can be pressed together as already described. A new hollow body 2 can then be attached to the freed holding device 9, and thus the holding devices 9 can be moved in a circuit through the system for applying the sleeve 1.

[0107] Preferably, the holding device 9 is removed as soon as the hollow body 2 is held in the holder 7 of the machine for attaching the protruding areas 6.

[0108] The holding device 9 can also be part of the system for applying the sleeve 1 and thus be moved in a circuit within the system. The holding device 9 picks up a hollow body 2 to be wrapped and moves it into the sleeve 1. This is usually done by the sleeve 1 being held and stretched at one end by several gripping elements 11, and the object to be wrapped being moved into the sleeve 1 from this side. As soon as the sleeve 1 is in the desired position, the gripping elements 11 can be opened or moved away and pulled downwards out of the sleeve 1. Alternatively, the gripping elements 11 can be opened or moved away, and the object with the sleeve 1 adhering to it can be moved further upwards by the holding device 9 until the sleeve 1 leaves the gripping elements 11 and comes into contact with the object. The gripping elements 11 are shown very briefly in Figs. 4, 8, and 9.In known devices, these can be considerably longer in order to expand the sleeve 1 over a larger portion or its entire length. The inner circumference of the expanded sleeve 1 can be larger in any area than the outer circumference of the formations 5, so that the sleeve 1 does not come into contact with the hollow body 2 during pulling, but only when the gripping elements 11 are removed from the sleeve 1. The gripping elements 11 can be in the form of finger-like holding elements 22, as illustrated in Fig. 12.

[0109] The holding device 9 of Fig. 3-6 comprises a radially adjustable head 10 made up of at least two elements. By moving the plurality of elements radially inwardly together, the holding device 9 can be moved from the first formation 5 into the hollow body 2. As soon as the adjustable head has reached the second formation 5, the plurality of elements can be moved radially outwardly apart until they rest against the inside of the second formation 5. At the other end, the holding device 9 can have a fixed head corresponding to the shape of the first formation 5, which rests against the inside of the first formation 5. The adjustable head 10 and the fixed head preferably each have a cylindrical region which projects beyond the respective formation 5 in the longitudinal direction of the hollow body 2.In the adjustable head 10, the cylindrical region is interrupted and is formed by the respective cylindrical partial surface of the individual elements of the adjustable head 10. The outer circumference of the cylindrical region can be greater than or equal to the outer diameter of the outermost edge of the recess 5. As a result, the second recess 5, in particular, is not subjected to any stress, or at least to a lesser degree, in the longitudinal direction of the hollow body 2 when the sleeve 1 is attached.

[0110] The same can also be achieved with a two-part holding device 9, as illustrated in Figs. 7-11. The loose head 12 can be inserted into the hollow body 2 from the other side after the other part of the holding device 9 has been inserted. The loose head 12 could be guided in the other part of the holding device 9 or have a detachable connection to it (neither shown).

[0111] When integrating this holding device 9 into a system for applying sleeves 1, the hollow bodies 2 can first be placed on a holder, which is the first part of the holding device 9. As illustrated in Fig. 8, the loose head 12 can be held above this holder by a gripping element 13, which, when the holder moves upwards, enters the hollow body 2 with the hollow body 2 and is transferred to the holder by the gripping element 13. The loose head 12 is therefore moved through the sleeve 1 as part of the holding device 9 until the state shown in Fig. 10 is achieved. The loose head 12 can then be lifted off and made available in the position shown in Fig. 8 for reuse on a hollow body 2 to be wrapped later. After removing the loose head 12 and the other part of the holding device, the state shown in Fig.1 so that the hollow body 2 can be machined in the machine to attach the protruding areas 6.

[0112] Finally, Figs. 6 and 11 illustrate variants in which the protruding portions 6 are attached to the holding devices 9. Since this requires the application of heat to weld the casing 1 to the barrier layer 4 through the holding devices 9, the complexity of the machine is increased. The lower part of the holding device 9 can be designed as a pressing element 8; a separate pressing element 8 will likely be required at the other end, since the application of heat from the movable head 10 or the loose head 14 would result in an even more complex device.

[0113] As illustrated, the movable head 10 can be countersunk into the hollow body 2 after radial contraction to create space for the pressing element 8. The countersinking of the movable head 10 can, for example, be effected passively by the pressing force of the pressing element 8. Alternatively, the loose head 12 can be removed beforehand by a gripper element 14.

[0114] The lower fixed head of the holding device 9 is briefly moved out of the hollow body 2 so that the protruding area 6 of the shell 1 can be formed inward. The lower fixed head can then be moved back into the hollow body 2 and, at the same time, the protruding area 6 can be welded to the pressing element 8.

[0115] Of course, it is also possible to remove the lower fixed head of the holding device 9 and to provide a second separate pressing element 8 instead.

[0116] Fig. 12 illustrates a further variant of a holding device 9. This is held frictionally in the interior of the hollow body 2, for example by comprising radially extendable elements or by being inflatable.

[0117] The formations 5 can optionally also be supported from the inside by radially extendable elements or radially inflatable areas. When the cover 1 is attached, it is pulled directly over the formations 5 so that, after releasing the gripping elements 11, the state shown in Fig. 1 is directly achieved, allowing the protruding areas 6 to be formed.

[0118] As further illustrated in Fig. 12, devices for applying a sleeve 1 are known in the prior art, in which long, finger-like holding elements 22 expand the sleeve 1 and hold it open until it is completely over the body to be packaged, or until the sleeve 1 is in the required position. The holding elements 22 are then pulled out of the sleeve 1, which can be assisted by blowing in air. When the holding elements 22 are pulled out, the sleeve 1 rests against the body to be packaged, in this case, against the hollow body 2.

[0119] It should be noted that the machine for applying the sleeve 1 can, in principle, correspond to the known state of the art, in particular with regard to the elements for stretching and covering the sleeve 1 and all elements for feeding the sleeve tube and for separating individual sleeves 1 from this sleeve tube. The mechanism for the relative movement between the sleeve 1 and the body to be packaged can also be according to the known state of the art. However, the holder of the hollow body 2 is different, since it is held on its inside when the sleeve 1 is applied, which is not possible with a closed body such as a beverage bottle.

[0120] The casing 1 is placed over the hollow body 2 such that it extends beyond the hollow body 2 at both ends. The length of these projecting areas 6 of the casing 1 is preferably between 3 and 6 mm. Preferably, the casing 1 extends beyond the hollow body 2 by the same amount at both ends. Therefore, the casing 1 must be positioned very precisely.

[0121] The hollow body 2 is preferably located at a defined position on the holding device 9 in its longitudinal direction. Preferably, the hollow body 2 is also located on the holding device with a defined orientation, i.e., with a defined circumferential position of a feature of the hollow body, such as an increase in thickness and / or the position of a seam in one of the layers of the hollow body. The holding device 9 preferably fixes the hollow body 2 in its longitudinal direction and also prevents rotation about its longitudinal axis.

[0122] The support of the hollow body 2 on its inner side is advantageous since this allows the cylindrical shape of the hollow body 2 to be stabilized and drying of the hollow body 2 can take place on its outer side, at least until the casing 1 is applied.

[0123] Fig. 13 schematically illustrates a variant embodiment in which the hollow body 2 is held in the device for connecting the protruding regions 6 of the casing 1 to the barrier layer 4 inside the hollow body 2. The connection takes place on the side facing away from the holding device 9, for example by means of the pressing element 8 shown. The hollow body 2 can then be lifted off the holding device 9 and turned over and placed back on the holding device 9 or a further holding device 9, whereupon the casing is connected to the barrier layer at the second end in the same or a different way. Alternatively, a transfer to a second holding device 9 can take place, which projects into the hollow body 2 from the opposite side, so that the second end can be processed without turning the hollow body 2.In one embodiment, a pressing element 8 can comprise a holding device that projects into the interior of the hollow body 2, so that the pressing element 8 takes over the hollow body from the illustrated holding device 9. The illustrated holding device 9 can then be moved out of the hollow body 2, and a second pressing element 8 can be moved into the hollow body 2 from this side.

[0124] Fig. 14 shows a second embodiment variant in which the hollow body 2 is held in the device for connecting the projecting areas 6 of the casing 1 to the barrier layer 4 inside the hollow body 2. As shown, in this case too, both ends of the hollow body 2 can be machined on both sides or simultaneously. This can be achieved by having an annular pressing element 8 around the holding device 9, which can be moved towards the hollow body 2. Alternatively, the holding force of the holding device 9 can be lower than the pressing force of the opposite pressing element 8, so that the upper pressing element 8 presses the hollow body 2 against the lower pressing element 8. The holding force of the holding device 9 can be before or afterduring the pressing of the upper holding element 8, or be completely eliminated, for example by adjusting adjustable or inflatable elements of the holding device radially inward or reducing their contact pressure. The lowering of the hollow body 2 onto the lower pressing element 8 can also be achieved by gravity, whereby the gravity of the hollow body 2 can also be sufficient to press the casing 1 against the barrier layer 4.

[0125] In all embodiments, the holding device 9 or the holder 7 can be designed to carry out a movement of the hollow body 2 in its longitudinal direction, so that the holding device 9 or the holder 7 presses the hollow body 2 against a pressing element 8.

[0126] As illustrated in Fig. 14, the lower pressing element 8 can be in the form of two half-shells, so that it can be placed around the holding device 9 at any time. This eliminates the need for the pressing element 8 to be constantly moved along with the holding device 9.

[0127] If the casing 1 is pressed against the barrier layer by compressed air, ring nozzles can be used to press all areas of the casing 1 simultaneously. Alternatively, a row of nozzles can be stationary on one or both sides of a transport path, with the hollow body 2 being rotated around its longitudinal axis on the holding device.

[0128] In one embodiment, a holding device 9 is used both in the machine for applying the casing 1 and in the machine for connecting the projecting areas 6 to the barrier layer 4, so that each hollow body 2 is moved through both machines with only one holding device 9.

[0129] In another embodiment, a transfer from a first holding device 9 to a second holding device 9 takes place between the two machines.

[0130] Less preferably, the hollow bodies 2 can also be stored temporarily between processing on the two machines or fed into a buffer system.

[0131] In a preferred variant, the machine for applying the casing 1 follows a machine for winding the individual layers of the hollow body into a continuous tube, which machine comprises a device for separating the individual hollow bodies 2 and is followed by a machine for forming the two formations 5, wherein said machines preferably cooperate in a continuous process. Between the machine for forming the two formations 5 and the machine for applying the casing 1, or even before the machine for forming the two formations 5, if necessary for drying, the separated individual hollow bodies 2 can be temporarily stored and / or the transport path of a transport line can be extended, for example by means of a buffer tower.

[0132] As already mentioned and illustrated in Fig. 15, in one embodiment, the inwardly projecting regions 6 of the sleeve 1 can only be connected to the barrier layer 4 upon placement of closure elements 15. The closure elements 15 are preferably in the form of a can lid and can base, which are known, for example, from aluminum cans. When placing a closure element 15, the edge region 16 of the closure element 15 is placed against the outwardly shaped hollow body edge, and the two edge regions are crimped together. By crimping, the edge region 16 of the closure element 15 and the edge region of the hollow body 2 are mechanically pressed together to create a tight connection.

[0133] Through mechanical compression, the inwardly projecting region 6 of the casing 1 is pressed against the barrier layer 4. In one embodiment, only this mechanical connection of the casing 1 with the barrier layer 2 is achieved by flanging the closure element 15.

[0134] In another embodiment, the casing 1 is also welded to the barrier layer 4. This can be done by attaching a heated closure element 15 or by subsequent heat exposure, for example by ultrasound, induction, thermal radiation, hot air, infrared light, UV light or laser.

[0135] If the closure element 15 has a plastic coating 17 on the inside or only in the area of ​​the flange, this can also be welded to the casing 1.

[0136] As is known from WO2022219176A1, the hollow body 2 can have an increased thickness at one point along its circumference. This increased thickness results from the fact that the barrier layer 4 is a wound layer, so that sealing the seam of this layer is necessary. The seam preferably runs straight and in the longitudinal direction of the hollow body. Possible variants for sealing the seam can be found in WO2022219176A1. The illustrated folded seam 20 (anaconda seam) represents a preferred form of the seam. The increased thickness can continue from the barrier layer 4 to the outside of the hollow body 2. However, the increased thickness could also be present on the inside of the hollow body 2.

[0137] The casing 1 also generally has a peripheral area with a thickness increase 21, in which there is a simple overlap of the material of the casing 1. The thickness increase 21 runs straight in the longitudinal direction of the casing 1.

[0138] It is preferred that the attachment of the sheath 1 to the hollow body 2 is carried out with controlled orientation, so that the thickness increase of the shell of the hollow body 2 and the thickness increase 21 of the sheath 1 are located at different circumferential areas.

[0139] As illustrated in Fig. 16, the thickness increase 21 of the shell 1 can be connected to the thickness increase of the hollow body 2.

[0140] In another embodiment, the thickness increase 21 of the shell 1 can be located at any position away from the thickness increase of the hollow body 2. It is also possible, but not necessary, for the thickness increases to be diametrically opposite each other on the circumference of the hollow body 2. The positioning of the thickness increase 21 of the shell 1 does not need to be particularly precise, as long as it lies within an angular range that lies outside the angular range of the thickness increase of the hollow body 2.

[0141] The thickness increase of the hollow body 2 and the thickness increase 21 of the shell 1 run in the longitudinal direction of the hollow body 2. Thus, the thickness increases do not cross.

Claims

PATENT CLAIMS 1. A method for placing an elastic sleeve (1) on a hollow body (2) open on both sides, which sleeve (1) is longer than the distance between the two opposite open ends of the hollow body (2) and which sleeve (1) in the unexpanded state has a smaller circumference than the hollow body (2) at its open ends, characterized in that the hollow bodies (2) open on both sides are held from the inside in a machine for applying the sleeve (1), wherein the respective sleeve (1) is expanded by a spreading effect at least at its end facing the hollow body (2) and is placed over the respective hollow body (2) in the longitudinal direction of the latter until the sleeve (1) projects beyond the lateral surface of the hollow body (1) at both open ends in the longitudinal direction of the hollow body (1), wherein the spreading effect is subsequently removed, whereupon the two edges of the sleeve (1) which project beyond the hollow body (2),protrude obliquely or vertically inwards from the opening edge of the hollow body (2), whereby the two inwardly projecting edges of the casing (1) are subsequently pressed against the inner surface of the hollow body (2) and connected thereto.

2. Method according to claim 1, characterized in that the respective hollow body (2) is cylindrical and has an outwardly shaped edge region at both open ends, in particular two opposite edge regions extending outwards along a radius, between which a cylindrical shell section of the hollow body (2) extends.

3. Method according to claim 1 or 2, characterized in that the inner surface of the respective hollow body (2) is formed by a barrier material which extends over the entire height of the hollow body (2) up to the two opening edges and the outer surface of the hollow body (2) consists of paper or cardboard material.

4. Method according to one of claims 1 to 3, characterized in that several hollow bodies (2) are moved simultaneously through the machine for applying the casings (1), each hollow body (2) being present on a holding element (8) which bears internally against the outer surface of the hollow body (2), wherein after the casing (1) has been applied, the hollow bodies (2) are transported further on the holding element (8) to a device which presses one or both of the inwardly projecting edges of the casing (1) onto the inner surface of the hollow body (2).

5. Method according to claim 4, characterized in that before or during pressing the inwardly projecting edges of the casing (1) onto the inner surface of the hollow body (2), heat is applied to the casing and the inner surface of the respective hollow body (2), the casing (1) and the inner surface being formed from plastic and being welded together. Method according to one of claims 1 to 5, characterized in that at least one of the two inwardly projecting edges of the casing (1) is pressed on by attaching a closure element which closes an opening in the hollow body (2). Method according to one of claims 1 to 6, characterized in that the respective hollow body (2) is supported from the inside by a holding element (8) over its entire cylindrical inner casing region when the casing (1) is attached. Method according to one of claims 1 to 7, characterized in that the respective hollow body (2) is supported from the inside by a holding element (8) over at least one outwardly shaped edge region of the hollow body (2) when the casing (1) is attached.Method according to one of claims 1 to 8, characterized in that the expansion of the sleeve (1) is achieved by a plurality of expansion elements which project into the interior of the sleeve (1), wherein the expansion elements bear against the inside of the sleeve (1) over a length of the sleeve (1) which amounts to at least half the length of the hollow body (2), wherein the plurality of expansion elements are present between the sleeve (1) and the hollow body (2) when the sleeve is placed and wherein they are pulled out from between the hollow body (2) and the sleeve (1) when the sleeve (1) is in the desired position on the hollow body (2). Method according to one of claims 1 to 9, characterized in that when at least one of the two inwardly projecting edges of the sleeve (1) is pressed and connected to the inner surface of the hollow body (2), a counterpressure is applied to the outside of the hollow body (2), in particular to an outwardly shaped edge region of the hollow body (2).Method according to claim 10, characterized in that the counterpressure is provided by a holder (7) which surrounds the hollow body (2). Method according to claim 11, characterized in that the counterpressure is provided by an expandable, in particular inflatable or pumpable element, which rests against the outer edge region of the hollow body (2) only in the expanded state. Method according to one of claims 1 to 9, characterized in that the attachment of the sleeve (1) to the hollow body (2) takes place with controlled orientation, so that an increase in the thickness of the shell of the hollow body (2) and an increase in the thickness (21) of the sleeve (1) are located at different circumferential regions.Method according to one of claims 1 to 9, characterized in that the pressing of at least one of the two inwardly projecting edges of the casing (1) against the inner surface of the hollow body (2) is carried out with a transparent stamp and a laser beam is directed through the transparent stamp onto the areas of the casing (1) and the inner surface of the hollow body (2) to be joined. Device for attaching an outer sleeve (1) to the inside of a hollow body (2) open on both sides, wherein the sleeve (1) is placed over the respective hollow body (2) in the longitudinal direction of the latter, wherein the sleeve (1) projects beyond the outer surface of the hollow body (1) in the longitudinal direction of the hollow body (1) at both open ends, wherein the two edges of the sleeve (1) which project beyond the hollow body (2) preferably project inwards at an angle or perpendicularly from the opening edge of the hollow body (2), characterized in that the device comprises holding devices (9) or holders (7) for holding a respective open hollow body (2), and wherein the device comprises pressing elements (8) for pressing the sleeve (1) against the inside of the hollow body (2) at at least one end of the open hollow body (2), wherein a relative movement between the pressing elements (8) and the holding devices (9) or holders (7) can be carried out by means of the device.Device according to claim 15, characterized in that it comprises means for welding the casing (1) to the inside of the hollow body (2) open on both sides. Device according to claim 15 or 16, characterized in that it comprises means for applying a counterpressure on the outside of the hollow body (2) against the pressing elements (8).

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