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

Abstract

The present invention relates to a method and apparatus for sealing a cut edge of a hollow article that is open at both ends and has a cover on the exterior of the hollow article.

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for sealing the cut end of a hollow article that is open at both ends using a sleeve around the hollow article.

[0002] A hollow article open at both ends may be provided with one closure element at each of its two ends to form a can and may contain a medium, the closure elements being present in the form of a base and a lid, as is known from cans in the form of aluminum cans or composite cans, for example beverage cans.

[0003] The hollow article, open at both ends, is a section of a continuous tube made of multiple layers, the innermost layer of which is a tight barrier layer. At least one other layer of the hollow article is made of a non-fluid-tight material, particularly paper, paperboard, or cardboard. The barrier layer prevents liquid or moisture from reaching the other layers from the inside of the hollow article.

[0004] When the open ended hollow article is cut, two cut edges of the other layer are exposed. [Background technology]

[0005] The prior art knows how to attach sleeves to packaging articles, in particular plastic articles such as PET bottles. This involves an elastic sleeve being placed over the packaging article and contacting the jacket surface of the packaging article. Depending on the attachment principle, a distinction is made between shrink sleeves and stretch sleeves: shrink sleeves shrink onto the packaging article under the action of heat, while stretch sleeves shrink solely due to their elastic properties and attach themselves to the jacket surface.

[0006] Cans and a method for producing them are known from the applicant's WO 2022219176, in which the sealing of the cut end of the can is, in one variant, achieved by a sleeve that is placed over a hollow article open at both ends in the form of a can jacket. WO 2022219176 has already disclosed that the sleeve can be in the form of an elongated sleeve and that the sleeve can be folded inward and connected to the inner barrier layer of the hollow article. It has also been disclosed that the hollow article can already have an outwardly bulging end region. A bulging end region is understood to mean a radial bulge of the jacket at the open end of the hollow article. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2022219176 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a method and an apparatus by which sleeves can be attached to the inside of hollow articles, especially in a continuous process. [Means for solving the problem]

[0009] To solve the above problem, in one variant embodiment, a method is proposed in which an outer sleeve is attached to the inside of a hollow article that is open at both ends.

[0010] To solve this problem, in one variant embodiment, a device is proposed for fitting an outer sleeve inside a hollow article that is open at both ends.

[0011] In one variant of the method of the invention, an elastic sleeve is attached in a first step to the hollow article, covering it at both ends. Preferably, the hollow article already presents a bulged edge, which is understood to mean an outwardly deformed edge region, in particular an end region extending outward along a radius.

[0012] As machines for placing the sleeve on the hollow article, known devices from the prior art for attaching sleeves to packaging articles can be used, in particular devices for attaching tension sleeves.

[0013] However, the difference with known methods is that the sleeve is attached over a hollow article that is open at both ends, and because the sleeve is longer than the hollow article, the sleeve covers both cut ends of the hollow article.

[0014] The use of an elastic foil as the overlay and sleeve material that shrinks after installation causes the overlapping edges of the sleeve to project obliquely or nearly perpendicularly from the jacket surface of the hollow article into the respective openings. This result of the first step thus constitutes a difference from the prior art.

[0015] The second step of the method of the invention is that at the cut end of the hollow article open at both ends, the inwardly projecting area of ​​the sleeve is pressed inward onto the barrier layer and tightly connected to it, preferably by welding the sleeve and the barrier layer together under the action of heat.

[0016] The heating action may be by a heated surface of the article pressing the inwardly projecting area of ​​the sleeve onto the barrier layer.

[0017] In an alternative embodiment, the heating action may be by hot air. In an alternative embodiment, the heating action may be by compressed hot air, whereby the inwardly protruding area of ​​the sleeve is pressed against the barrier layer by the compressed air.

[0018] In other variations, the heating may be by ultrasound or induction. In other variations, the heating may be by laser. In another variation, the heating may be by thermal irradiation. In another variation, the heating may be by infrared light.

[0019] If the welding is performed or assisted by a laser, the sleeve is preferably pressed onto the barrier layer by a transparent pressing element, in particular a transparent stamp, and at least one laser beam passes through the transparent pressing element to reach the area to be welded.

[0020] The welding method may be used at either end of the hollow article or at both ends. Multiple methods may be used in combination, with two or more power sources operating simultaneously, or one power source being used first followed by a second, different power source. In this manner, an initial pre-weld may be performed using one power source, and the weld may then be completed using a second power source. In one alternative embodiment, the two welding steps differ in the type, level, or presence of counter pressure on the outside of the hollow article and / or the type, presence, or presence of a pressure element or pressure on the inside of the hollow article.

[0021] In another alternative embodiment, adhesive may be used to connect the sleeve to the barrier layer. The adhesive may be applied to the inwardly projecting area of ​​the sleeve or to the barrier layer.

[0022] In one alternative embodiment, the adhesive may be a heat-activatable adhesive, while in another alternative embodiment, the adhesive may be a light-activatable adhesive, in particular UV light-activatable adhesive.

[0023] Attaching the inwardly projecting region of the sleeve to the inside of the barrier layer can be done the same at both ends of the hollow article or by different methods selected from those described herein.

[0024] In an alternative embodiment, the sleeve or hollow article is heated before attaching the sleeve to the barrier layer. In an alternative embodiment, the sleeve and hollow article are heated before attaching the sleeve to the barrier layer. Such heating occurs or begins before the inwardly protruding region of the sleeve is pressed against the inside of the barrier layer of the hollow article.

[0025] The connection of the inwardly projecting region of the sleeve to the barrier layer is preferably already carried out in the plant for laying the sleeve or subsequently. In known plants for laying the sleeve, the packaging articles are continuously moved along a line and / or through a carousel. The mechanical device for stretching the sleeve over the partial region can be moved together with the packaging articles.

[0026] Preferably, the machine for placing the sleeve is followed by a station of the present invention for connecting the protruding regions of the sleeve to the barrier layer. Preferably, the two protruding regions are simultaneously pressed into the diametrically opposed openings of the hollow article, i.e., connected to the barrier layer. In another variant, the two diametrically opposed openings are processed sequentially. In this case, the hollow article may be rotated after the sleeve and barrier layer are connected on the first side, or the hollow article may be transferred from the first holder to the second holder.

[0027] In another alternative embodiment, after the sleeve and barrier layer are connected at a first end, a first sealing element is attached to the first end, and then the sleeve and barrier layer are connected at a second end, which may be the bottom or lid of the can.

[0028] After the sleeve and barrier layer are connected at the second end, the hollow article sealed at one end may be filled, and then a second sealing element may be attached to the second end. The connection of the sleeve and barrier layer at the second end may also occur simultaneously or overlapping with the filling process.

[0029] The filling may be performed immediately adjacent to the station for sealing the first end of the hollow article at the same location, or the hollow article may be transported to the filling plant after the two cut ends have been sealed or after the first open end has been sealed.

[0030] Either or each of the two sealing elements may be attached to the hollow article in a preheated state.

[0031] Preferably, the inwardly projecting region of the sleeve is pressed against the barrier layer by a pressing element which is moved vertically towards the opening face until it contacts the inside of the outwardly bulging edge region of the hollow article.

[0032] Preferably, during this process, the hollow article is held directly beneath the outer bulge by a retaining element that creates the necessary counter pressure on the outside of the outer bulge to prevent deformation or damage to the outer bulge while the pressing element is pressing.

[0033] Preferably, there is one retaining element at each of the two ends of the hollow article, or alternatively, there may be one retaining element extending across the height of the hollow article to apply opposing pressure to both outwardly bulging hollow article edges.

[0034] The holding element may be made of a dimensionally stable material such as metal or plastic. In an alternative embodiment, the holding element has an elastic surface, in particular made of rubber, silicone or another elastic material.

[0035] In one variant embodiment, the retaining element comprises an inflatable or pumpable or differently expandable article contacting the hollow article, in particular its outwardly bulging hollow article edge. The inflatable or pumpable article may be a ring which, in a non-expanded state, can be moved outside the outwardly bulging hollow article edge, but which reduces its inner diameter when expanded.

[0036] In another alternative embodiment, the hollow article is held from the inside.

[0037] Preferably, the hollow article is held by a predetermined layer of the side seam of the sleeve and / or a thicker region of the jacket of the hollow article. In one alternative embodiment, the holding element may have a recess for the side seam of the sleeve and / or a recess for receiving the thicker region of the hollow article that is present on the outside of the jacket. In one alternative embodiment, the holding element on the inside of the hollow article may have a recess for receiving the thicker region of the hollow article that is present on the inside of the jacket. In one alternative embodiment, the pressing element that presses the inwardly protruding region of the sleeve against the barrier layer may have a recess for receiving the side seam of the sleeve and / or a recess for receiving the thicker region of the jacket.

[0038] Preferably, the plant comprises a carousel or line, and a plurality of pressing units comprising pressing elements and holding elements travel together with the hollow articles which are moved along the carousel or line.

[0039] In an alternative embodiment, the hollow articles may also be stationary when the sleeve is pressed by the pressing element, and preferably, multiple pressing elements are pressed simultaneously onto multiple stationary hollow articles, which may be done by stopping the conveying device for the hollow articles for this process, or by removing the hollow articles from the continuously moving conveying device for this process and returning them to the continuously moving conveying device after the process.

[0040] This procedure, in which stationary hollow articles are processed as a group, may be called a batch process.

[0041] In another variant, the inwardly protruding region of the sleeve is connected to the barrier layer only when the sealing element is placed. The sealing element is preferably present on the can lid and can bottom. When placing the sealing element, the edge region of the sealing element is placed on the outwardly bulging edge of the hollow article, and the two edge regions are crimped together. The crimping mechanically presses the edge region of the sealing element and the edge region of the hollow article together to form a tight connection. The mechanical crimping presses the inwardly protruding region of the sleeve onto the barrier layer. In one variant, the sleeve is mechanically connected to the barrier layer only once by crimping the sealing element.

[0042] In an alternative embodiment, either or both of the two sealing elements may be attached to the hollow article in a preheated state.

[0043] In another variant, additional welding of the sleeve to the barrier layer is performed, which may be by attaching a heated sealing element or by subsequent heating, for example by ultrasound, induction, thermal radiation, hot air or laser.

[0044] If the sealing element has a plastic coating on its inside, this coating may also be welded to the sleeve.

[0045] A variant embodiment of the invention consists in a method of attaching a sleeve to the outside of a hollow article that is open at both ends, the hollow article being held from its inside while the sleeve is attached, the sleeve being longer than the hollow article and covering the hollow article at both ends of the hollow article after attachment.

[0046] One alternative embodiment of the present invention is a device for attaching a sleeve to the outside of a hollow article having open ends, wherein a retaining device projects into the inside of the hollow article and contacts the inside of the hollow article, the hollow article being present in the retaining device at a predetermined length and in a predetermined orientation.

[0047] A variant embodiment of the invention resides in a method in which in a first step a sleeve is attached to the outside of a hollow article open at both ends, which after attachment covers the hollow article at both ends, and in a second step the protruding areas of the sleeve are fastened to the inside of the hollow article, which first step can be carried out using methods and devices known in the prior art.

[0048] One variant embodiment relates to a method for placing an elastic sleeve on each hollow article having an opening at both ends, the elastic sleeve having a length greater than the distance between the two opposite ends of the hollow article and a smaller circumference in an unstretched state than the hollow article has at its open end, in which the open-ended hollow articles are held from the inside in a machine for attaching the sleeves, and each sleeve is stretched by spreading at least at its end facing the hollow article, and is placed on each hollow article in the longitudinal direction of the hollow article until the sleeve covers the jacket surface of the hollow article at both open ends, and then the spreading action is removed, so that the two edges of the sleeve covering the hollow article protrude inwardly from the open edges of the hollow article diagonally or vertically, and then the two inward-protruding edges of the sleeve are pressed against the inner surface of the hollow article and connected to it.

[0049] In this method, each hollow article is preferably cylindrical and has outwardly bulging edge regions at both open ends, in particular two diametrically opposed edge regions that extend outward along radii between which the cylindrical jacket section of the hollow article extends.

[0050] In this method, the inner jacket surface of each hollow article is formed by a barrier material extending over the height of the hollow article up to the two opening edges, and the outer jacket surface of the hollow article is preferably made of a paper or cardboard material.

[0051] In this method, a plurality of hollow articles are moved simultaneously through a machine for attaching sleeves, each of the hollow articles resting on a retaining element that contacts the jacket surface of the hollow article on the inside, and after attaching the sleeve, the hollow articles are preferably transported further on the retaining element to a device that presses one or both of the inwardly protruding edges of the sleeve against the inner surface of the hollow article.

[0052] In this method, heating is applied to the sleeve and inner jacket surface of each hollow article before or while the inwardly protruding edge of the sleeve is pressed against the inner surface of the hollow article, the sleeve and inner jacket surface being preferably made of plastic and welded to one another.

[0053] In one variant of the method, the pressing of at least one of the two inwardly projecting edges of the sleeve is carried out by attaching a sealing element that seals the opening of the hollow article.

[0054] Each hollow article is preferably supported from the inside by a retaining element across its cylindrical inner jacket area while the sleeve is attached.

[0055] Each hollow article is preferably supported from the inside by a retaining element in at least one edge region of the outwardly bulging hollow article while the sleeve is attached.

[0056] In this method, stretching of the sleeve is preferably carried out by a plurality of expansion elements protruding inwardly from the sleeve, the expansion elements contacting the sleeve on the inside over a length equal to at least half the length of the hollow article, the plurality of expansion elements being present between the sleeve and the hollow article while the sleeve is in position, and the plurality of expansion elements being withdrawn from between the hollow article and the sleeve when the sleeve is in its desired position on the hollow article.

[0057] In this method, it is preferred that a counter pressure be applied to the outside of the hollow article, in particular to the outwardly bulging edge region of the hollow article, while at least one of the two inwardly protruding edges of the sleeve is pressed and connected to the inner surface of the hollow article.

[0058] In particular, the counter pressure is preferably applied by a holder that surrounds the hollow article.

[0059] In particular, the counter pressure is preferably exerted by an expandable, in particular inflatable or pumpable, element which contacts the outer edge region of the hollow article only in the expanded state.

[0060] Preferably, the attachment of the sleeve to the hollow article is performed in a controlled orientation so that the thicker areas of the jacket of the hollow article and the thicker areas of the sleeve are located in different circumferential regions.

[0061] It is preferred that pressing at least one of the two inwardly protruding edges of the sleeve against the inner surface of the hollow article is carried out using a transparent stamp, and that a laser beam is directed at the area of ​​the sleeve and the inner surface of the hollow article so as to be connected via the transparent stamp.

[0062] A variant embodiment relates to an apparatus for attaching an external sleeve to the inside of a hollow article that is open at both ends, wherein the sleeve is arranged over each hollow article in its longitudinal direction, the sleeve covers the jacket surface of the hollow article at both open longitudinal ends of the hollow article, and the two edges of the sleeve covering the hollow article preferably protrude inwardly obliquely or perpendicularly from the open edges of the hollow article, the apparatus comprises holding devices or holders each for holding one open hollow article, the apparatus comprises pressing elements for pressing the sleeve against the inside of the hollow article at at least one end of the open hollow article, and relative movement between the pressing elements and the holding elements or holders can be performed via the apparatus.

[0063] The apparatus preferably comprises means for welding a sleeve to the inside of the hollow article which is open at both ends.

[0064] The device preferably comprises means for applying a counter pressure to the outside of the hollow article opposite the pressing element.

[0065] Preferably, the sleeve is placed on the hollow article according to the method described herein before reaching the apparatus for attaching an outer sleeve to the inside of each open ended hollow article.

[0066] Although less preferred, the sleeve may also be arranged in a different manner, so long as the sleeve surrounds the hollow article on its outside and overlies it at both open ends.

[0067] Preferably, the sleeve is a tension sleeve. Less preferably, the sleeve may be a shrink sleeve.

[0068] The invention will now be further explained on the basis of the following embodiments illustrated in the drawings. [Brief explanation of the drawings]

[0069] [Figure 1] 1 shows a schematic view of a device for fastening an outer sleeve inside a hollow article that is open at both ends in an open state; [Figure 2] 1 shows a schematic view of a device for fastening an outer sleeve inside a hollow article that is open at both ends and in a closed state; [Figure 3] 1A-1C are diagrams illustrating a procedure for receiving a hollow article having open ends into a first exemplary holder. [Figure 4] 10A-10C are diagrams illustrating a procedure for inserting a first exemplary holder with a hollow article open at both ends thereon into a sleeve. [Figure 5] 1 is a schematic diagram of a first exemplary holder on which a hollow article having open ends within a sleeve is placed; FIG. [Figure 6]6 shows a schematic view of a device for fastening a sleeve inside a hollow article comprising the first exemplary holder of FIGS. 3 to 5. FIG. [Figure 7] 10A-10C are diagrams illustrating a procedure for receiving a hollow article having open ends into a second exemplary holder. [Figure 8] A diagram schematically illustrating combining a second exemplary holder with a loosely present element before inserting the second exemplary holder, on which a hollow article having open ends is present, into a sleeve. [Figure 9] 10A-10C are schematic diagrams illustrating the procedure for inserting a second exemplary holder with a hollow article open at both ends thereon into a sleeve. [Figure 10] 10 is a schematic diagram of a second exemplary holder on which a hollow article having open ends within a sleeve is placed. FIG. [Figure 11] 11 shows a schematic view of a device for fastening a sleeve inside a hollow article comprising the second exemplary holder of FIGS. 7 to 10. FIG. [Figure 12] 10A and 10B show another modification for attaching the sleeve. [Figure 13] FIG. 10 shows the inner holder of the hollow article when connecting the sleeve to the barrier layer. [Figure 14] FIG. 10 shows the inner holder of the hollow article when connecting the sleeve to the barrier layer. [Figure 15] 10 shows a variant for connecting a sleeve to a barrier layer by sealing the hollow article with a sealing element. [Figure 16] FIG. 10 illustrates an offset arrangement of thicker regions of the jacket and sleeve of a hollow article. DETAILED DESCRIPTION OF THE INVENTION

[0070] These figures are schematic and not to scale.

[0071] It should be noted that the illustrated embodiments only show possible embodiments, and the present invention is not limited to these specifically shown variant embodiments, and that combinations between individual variant embodiments, as well as combinations of one embodiment with the general description above, are possible. Such other possible combinations do not need to be explicitly mentioned, since they are within the knowledge of a person skilled in the art based on the technical teachings of the present invention.

[0072] The scope of protection is defined by the claims. However, the specification and drawings should be used when interpreting the claims. Individual features or combinations of features from the various embodiments shown and described may represent separate inventive solutions in themselves. The underlying purpose of such separate inventive solutions can be understood from the description.

[0073] 1 and 2 show a device for fastening an outer sleeve 1 inside a hollow article 2 that is open at both ends. The hollow article 2 comprises a multi-layer jacket that comprises at least one outer layer 3 made of an absorbent and / or liquid-resistant material. Preferably, the hollow article 2 comprises several such outer layers 3.

[0074] The hollow article 2 has on its inside a liquid-tight barrier layer 4. The barrier layer 4 is particularly tight to the contents of the finished packaging article. The barrier layer 4 forms the closed inner wall of the hollow article 2.

[0075] To form the hollow article 2, the layers are preferably first produced by winding into a continuous tube from which individual hollow articles 2 are subsequently cut, exposing the outer layer 3 or layers 3 at the cut edge of the hollow article 2.

[0076] After separation of the individual hollow articles 2, each of them has an edge region that bulges outwards, i.e. that widens radially outwards. The bulges 5 are preferably present as radial areas.

[0077] The outer layer 3, ie the outermost of the layers 3 of the hollow article 2, may be made on its outside from an absorbent and / or non-liquid-resistant material.

[0078] The outer layer 3 or each of the outer layers 3 is preferably made of cardboard, paperboard or paper, with kraft paper being preferred.

[0079] 1 and 2, there is already an outer sleeve 1 around the hollow article 2. The sleeve 1 can be placed over the hollow article 2 using a machine for fitting stretch sleeves, or the hollow article can be pressed into the sleeve 1 using a machine for fitting stretch sleeves. Such machines are known in the prior art.

[0080] However, and most importantly for the present invention, the sleeves 1 are made longer than the hollow articles 2 so that the sleeves 1 cover both cut edges of the hollow articles 2. Thus, there is a protruding area 6 of each sleeve 1.

[0081] Although the protruding regions 6 are shown extending perpendicular to the longitudinal direction of the hollow article 2, they may also protrude obliquely inward.

[0082] It is the task of the device to press the protruding areas 6 inwards onto the barrier layer 4 and fasten them there.

[0083] A variant embodiment of the machine for fastening the protruding regions of the sleeve 1 comprises at least one holder 7 for each hollow article 2 that is moved simultaneously through the machine. As shown, there may be two holders 7 per hollow article 2, one in each end region.

[0084] In one alternative embodiment, the holder 7 can start from the center of the hollow article 2 and press the sleeve 1 against the center of the hollow article 2. The holder 7 is then pulled away to the edge of the hollow article 2. This facilitates the removal of any air that may be present between the hollow article 2 and the sleeve 1. This also allows the sleeve 1 to contact the hollow article 2 with a better fit if the elastic reset force is insufficient. In a less preferred alternative embodiment, the holder 7 can be heated to sorb the sleeve 1. However, the use of a stretched sleeve is preferred.

[0085] Preferably, the holder 7 surrounds the outer periphery of the hollow article 2 at either of the end regions. As shown, the holder 7 may have a radial extent formed to correspond to the bulge 5. Alternatively, the holder 7 may also hold the hollow article 2 closely spaced from the bulge 5.

[0086] Preferably, each hollow article 2 is grasped by a holder 7 (i.e., by two holders 7) as it reaches the machine and then moved through the machine by said holder(s) 7 until the hollow article 2 is removed from the machine or passed to another machine.

[0087] When the hollow article 2 is held in the holder 7, two pressing elements 8 can be transferred to the two open ends of the hollow article 2 to press the protruding regions 6 of the sleeve 1 onto the barrier layer 4. Preferably, the protruding regions 6 only contact the bulges 5 and thus do not protrude completely into the vertical region of the inner hollow article wall.

[0088] Preferably, the pressure element 8 has a surface profile in the region of the bulge 5 that corresponds to the shape of the bulge 5. The surface profile may have recesses for the thicker regions 21 of the sleeve 1. The surface profile may also have recesses for the thicker regions of the hollow article 2.

[0089] By having the pressure element 8, and preferably also the holder 7, correspond to the shape of the bulge 5 facing it, the shape of the bulge 5 is maintained while the protruding region 6 is attached.

[0090] Once the protruding region 6 is connected to the barrier layer 4, in particular fused or caulked, the pressing element 8 may be moved out of the hollow article 2 and the hollow article 2 may be removed from the holder 7 or transported from the holder 7 to another part of the plant.

[0091] The pressing element 8 is preferably moved through the machine together with the holder 7 and the hollow article 2 .

[0092] Less preferably, instead of a pressing element 8 which simultaneously presses the protruding region 6 around the entire circumference, a rotating or pivoting pressing element may be used which starts from one or more points and presses the protruding region 6 around the entire circumference.

[0093] Preferably, a number of devices, each comprising one or two holders 7 and two pressing elements 8, are arranged on the carousel, and the hollow articles 2 are moved along partial areas of the circumference of the carousel.

[0094] Less preferably, a number of devices, each comprising one or two holders 7 and two pressing elements 8, may be moved along the line and returned to the beginning of the line once the hollow articles 2 have been released at the end of the line.

[0095] Less preferably, the holder 7 and the pressing element 8 may also be moved together with the hollow article 2 independently of each other.

[0096] Alternatively, several devices, each with one or two holders 7 and two pressing elements 8, may each be stationary on a conveying path (carousel or line) for the hollow articles 2, each device taking turns removing a hollow article 2 from the line upon completion of installation and handing it over to another line.

[0097] A machine for attaching the sealing element may follow the machine for attaching the protruding region 6 to either of the two ends of the hollow article 2. The sealing element is preferably placed on the bulge 5 and rolled up into the bulge. The bulge 5, and therefore the protruding region 6 fastened to the barrier layer 4, is also included in the bulge of the sealing element and mechanically crimped thereto. The hollow article 2 can then be filled from the still-open end and subsequently sealed in the same manner using a second sealing element. At least the filling of the hollow article and the placement of the second sealing element take place in a moist environment, so it is important that the cut edge be protected by the sleeve 1.

[0098] After placing the machine and / or the first sealing element for applying the projecting region 6, intermediate storage of the hollow article 2 may also take place until the hollow article 2 is removed for filling.

[0099] The sleeve 1 and / or the outer layer 3 may exhibit some printing.

[0100] 3 to 11 are not directly related to the core issue of pressing the protruding region 6, but may be considered as preliminary steps in the preferred process or preferred plant.

[0101] FIG. 3 shows a first variant of a holding device 9 for a hollow article 2 which can be moved through a machine for mounting a sleeve 1 together with the hollow article 2 .

[0102] The holding device 9 can perform two functions. First, it can have a shape that corresponds to the shape of an object that has previously been provided with a sleeve using known devices. Such objects, in particular bottles, have a conical upper region that initially advances when the object is pushed into the sleeve. The holding device 9 therefore has an upper end that covers the hollow object 2 upon insertion into the sleeve 1, and this upper end comprises a tapered, in particular conical or rounded, region. The stretching of the sleeve 1 is thus advantageously performed by the holding device 9 and not by the bulge 5 of the hollow object 2.

[0103] A second task of the holding device 9 is to stabilize the hollow article 2 from the inside, especially in the region of the bulge 5 .

[0104] In a variant embodiment, the holding device 9 may be present as a packaging dummy, meaning that instead of a known object such as a bottle, a packaging dummy with the holding device 9 and the hollow article 2 present thereon is moved through the plant for attaching the sleeve 1. The packaging dummy is picked up by the plant in a holder like a conventional object to be packaged and moved through the plant. The result is a packaging dummy according to FIG. 5 or FIG. 10. When the holding device 9 is removed from the hollow article 2, the protruding area 6 contracts, so that the state of FIG. 1 is achieved, and the protruding area 6 can be pressed as described above. A new hollow article 2 can then be placed in the vacant holding device 9, which can then be circulated and moved through the plant for attaching the sleeve 1.

[0105] Preferably, the removal of the holding device 9 takes place after the hollow article 2 has been held in a holder 7 of a machine for attaching the protruding regions 6 .

[0106] However, the holding device 9 may also be part of the plant for attaching the sleeve 1 and may therefore be moved around in the plant. The holding device 9 then picks up the hollow article 2 to be sleeved and moves the hollow article 2 into the sleeve 1. This is usually done by holding and stretching the sleeve 1 at one end with multiple gripping elements 11, and then moving the object to be sleeved into the sleeve 1 from this end. Once the sleeve 1 is in its desired position, the gripping elements 11 can be opened or released and pulled downward from the sleeve 1. Alternatively, the gripping elements 11 can be opened and released while the sleeve 1, together with the object attached to the object, leaves the gripping elements 11 and is moved further up until it contacts the object. The gripping elements 11 are shown as very short in FIGS. 4, 8, and 9. In known devices, they can be significantly longer to stretch the sleeve 1 over a larger partial area or over its entire length. The inner circumference of the stretched sleeve 1 may be greater in each region than the circumference of the bulge 5 so that the gripping elements 11 do not come into contact with the hollow article 2 when the sleeve 1 is put on, only when they are removed from the sleeve 1. The gripping elements 11 may be present as finger-shaped holding elements 22, as shown in Figure 12.

[0107] The holding device 9 of Figures 3 to 6 comprises a radially adjustable head 10 made of at least two elements. The holding device 9 can be moved from the first bulge 5 into the hollow article 2 by moving the elements radially inward. When the adjustable head reaches the second bulge 5, the elements can be moved radially outward until they contact the inside of the second bulge 5. At the other end, the holding device 9 can have a solid head corresponding to the shape of the first bulge 5 and contacting the inside of the first bulge 5. Preferably, the adjustable head 10 and the solid head each have a cylindrical region that covers the respective bulge 5 in the longitudinal direction of the hollow article 2. In the case of the adjustable head 10, the cylindrical region is permanently present and is formed by the cylindrical partial surfaces of each of the individual elements of the adjustable head 10. The outer periphery of the cylindrical region can be equal to or greater than the outer diameter of the outer edge of the bulge 5. This means that there is no or at least less strain on the second bulge 5, particularly in the longitudinal direction of the hollow article 2.

[0108] The same can be achieved by a two-part retaining device 9 as shown in Figures 7 to 11. A loose head 12 can be inserted into the hollow article 2 from the other end. The loose head 12 may be guided in the other part of the retaining device 9 or may have a releasable connection to the other part (both not shown).

[0109] If such a holding device 9 is included in a plant for attaching a sleeve 1, the hollow article 2 may first be placed on a holder, which is the first part of the holding device 9. As shown in FIG. 8, the loose head 12 may be held above the holder by a gripping element 13, so that the loose head 12 reaches the hollow article 2 when the holder is moved upward together with the hollow article 2 and transferred to the holder by the gripping element 13. The loose head 12 is then moved through the sleeve 1 as part of the holding device 9 until the state of FIG. 10 is reached. The loose head 12 can then be lifted and provided in the position shown in FIG. 8 for later reuse with the hollow article 2 to be sleeved. After removing the loose head 12 and the other part of the holding device, the state of FIG. 1 is restored, and the hollow article 2 can be processed in a machine for attaching the protruding region 6.

[0110] 6 and 11 show a variant in which the attachment of the protruding region 6 is carried out on a holding device 9. This increases the complexity of the machine, since it requires a heating action to weld the sleeve 1 to the barrier layer 4 via the holding device 9. The lower part of the holding device 9 may be implemented as a pressing element 8, while the other end would probably need its own pressing element 8, since the heating action via a movable or loose head 10 would further increase the complexity of the machine.

[0111] As shown, the movable head 10 can be lowered into the hollow article 2 following contact radial contraction to make room for the pressure element 8. The lowering of the movable head 10 can be done passively, for example, by the pressure force of the pressure element 8. Alternatively, the loose head 12 can be removed first by the gripping element 14.

[0112] The lower solid head of the holding device 9 is temporarily removed from the hollow article 2 to allow the protruding region 6 of the sleeve 1 to assume its inner shape. The lower solid head can then be placed back into the hollow article 2 for welding on the protruding region 6 simultaneously with the pressing element 8.

[0113] Of course, it is also possible to remove the lower solid head of the holding device 9 and provide a second separate pressing element 8 instead.

[0114] 12 shows another variant of the retaining device 9. The retaining device 9 is frictionally engaged inside the hollow article 2, for example by comprising a radially expandable element or by being inflatable.

[0115] Optionally, the bulge 5 may also be supported from the inside by a radially expandable element or region. When the sleeve 1 is attached, it is pulled over the bulge 5 so that the situation of Figure 1 is directly achieved by releasing the gripping element 11 and the protruding region 6 can be attached.

[0116] 12, devices for attaching sleeve 1 are known in the prior art, in which long, finger-shaped retaining elements 22 stretch sleeve 1 and hold it open until it has completely covered the article to be packaged, or until it is in its required position. Retaining element 22 is then withdrawn from sleeve 1, potentially assisted by blowing air. As retaining element 22 is withdrawn, sleeve 1 contacts the article to be packaged, in this case hollow article 2.

[0117] It is noted that the machine for applying the sleeves 1 may generally be one known in the prior art, in particular with regard to all elements for stretching and covering the sleeves 1, and for delivering the sleeve tube and separating the individual sleeves 1 from this sleeve tube. The mechanism for causing relative movement between the sleeve 1 and the article to be packaged may be present as known in the prior art.

[0118] However, what is different is the way in which the hollow article 2 is held, as when the sleeve 1 is attached the hollow article 2 is held inside the hollow article 2, which is not possible with closed articles such as beverage bottles.

[0119] The sleeve 1 is placed on the hollow article 2 so as to cover both ends of the hollow article 2. The length of the protruding region 6 of the sleeve 1 is preferably 3 mm to 6 mm. Preferably, the sleeve 1 covers the hollow article 2 by the same amount at both ends. Therefore, the placement of the sleeve 1 must be particularly accurate.

[0120] The hollow article 2 is preferably in a predetermined position in its longitudinal direction on the holding device 9. Preferably, the hollow article 2 also has a predetermined orientation on the holding device, i.e., predetermined circumferential positions of features of the hollow article, such as thicker areas of one of the layers of the hollow article and / or the location of seams. The holding device 9 preferably fixes the hollow article 2 in its longitudinal direction, including against rotation about its longitudinal axis.

[0121] Holding the hollow article 2 inside it is advantageous as it stabilizes the cylindrical shape of the hollow article 2 and allows the outside of the hollow article 2 to dry, at least until the sleeve 1 is attached.

[0122] FIG. 13 shows a schematic diagram of a variant in which the hollow article 2 is held in a device for connecting the protruding region 6 of the sleeve 1 to the barrier layer 4 from the inside of the hollow article 2. The connection is made at the end facing away from the holding device, for example, by a pressing element 8 as shown. The hollow article 2 can then be lifted from the holding device 9, rotated, and placed back onto the holding device 9 or onto another holding device 9, whereupon the sleeve is connected to the barrier layer in an identical or different way at the second end. Alternatively, the hollow article 2 can be transferred from the opposite end to a second holding device 9 that protrudes into the hollow article 2, so that the second end can be processed without rotating the hollow article 2. In a variant, the pressing element 8 can comprise a holding device that protrudes into the hollow article 2, so that the pressing element 8 takes over the hollow article from the holding device 9 as shown. The holding device 9 as shown can then be moved out of the hollow article 2, and the second pressing element 8 can be moved into the hollow article 2 from this end.

[0123] FIG. 14 shows a second variant embodiment in which the hollow article 2 is held in a device for connecting the protruding region 6 of the sleeve 1 to the barrier layer 4 from the inside of the hollow article 2. As shown, processing the two ends of the hollow article 2 can again be performed simultaneously at both ends. This can be facilitated by the presence of an annular pressing element 8 around the holding device 9, which is movable toward the hollow article 2. Alternatively, the holding force of the holding device 9 can be lower than the pressing force of the opposing pressing element 8, so that the upper pressing element 8 presses the hollow article 2 against the lower pressing element 8. The holding force of the holding device 9 can be reduced or completely removed before or during pressing against the upper holding element 8, for example, by adjusting adjustable or expandable elements of the holding device radially inward and / or reducing their pressing force. Lowering the hollow article 2 onto the lower pressing element 8 can also be achieved by using gravity, which can also be sufficient to press the sleeve 1 onto the barrier layer 4.

[0124] In all variant embodiments, the holding device 9 or holder 7 can be designed to effect a longitudinal movement of the hollow article 2 such that the holding device 9 or holder 7 presses the hollow article 2 against the pressing element 8 .

[0125] As shown in Figure 14, the lower pressure element 8 can be in the form of two half shells so that it can be positioned at any time around the holding device 9. This means that the pressure element 8 does not have to be constantly moved together with the holding device 9.

[0126] If the sleeve 1 is pressed against the barrier layer by compressed air, a ring nozzle may be used to simultaneously press all areas of the sleeve 1. Alternatively, a series of nozzles may be stationary at either or both ends of the conveying path, and the hollow article 2 is rotated on the holding device about its longitudinal axis.

[0127] In one alternative embodiment, a holding device 9 is used in both the machine for attaching the sleeve 1 and the machine for connecting the protruding region 6 to the barrier layer 4, so that each hollow article 2 is moved through both machines using a single holding device 9.

[0128] In another variant, there is a handover from the first holding device 9 to the second holding device 9 between the two machines.

[0129] Although less preferred, the hollow articles 2 may also be stored intermediately or delivered to a buffer system while being processed by the two machines.

[0130] In one preferred variant, the machine for applying the sleeve 1 follows a machine for winding the individual layers of hollow articles into a continuous tube, which machine is equipped with a device for separating the individual hollow articles 2 and is followed by a machine for forming two bulges 5, said machines preferably cooperating in a continuous process. If required for drying, intermediate storage of the separated individual hollow articles 2 and / or an extension of the conveying path of the conveying line can be provided between the machine for forming the two bulges 5 and the machine for applying the sleeve 1, for example by means of a buffer tower, or even before the machine for forming the two bulges 5.

[0131] In a variant embodiment, as previously described and shown in Figure 15, the inwardly projecting region 6 of the sleeve 1 can be connected to the barrier layer 4 only when the sealing element 15 is placed. The sealing element 15 is preferably present as a can lid and can bottom, as known from aluminum cans, for example. When the sealing element 15 is placed, the edge region 16 of the sealing element 15 comes into contact with the outwardly bulging edge of the hollow article, and the two edge regions are crimped together. Said crimping mechanically presses the edge region 16 of the sealing element 15 and the edge region of the hollow article 2 together, forming a tight connection.

[0132] Said mechanical crimping presses the inwardly projecting area 6 of the sleeve 1 onto the barrier layer 4. In a variant embodiment, this mechanical connection of the sleeve 1 to the barrier layer 4 by crimping the sealing element 15 is unique.

[0133] In another variant, additional welding of the sleeve 1 to the barrier layer 4 is performed, either by applying a heated sealing element 15 or by subsequent heating, for example by ultrasound, induction, thermal radiation, hot air, infrared light, UV light or laser.

[0134] If the sealing element 15 has a plastic coating 17 only on its inside or in the area of ​​the flange, this coating can also be welded to the sleeve 1 .

[0135] As known from WO 2022219176, the hollow article 2 may have a thicker region at one point on its periphery. This thicker region results from the barrier layer 4 being a wound layer, so that the seam of this layer does not require sealing. Preferably, the seam runs straight in the longitudinal direction of the hollow article. Possible variations for sealing the seam can be taken from WO 2022219176. The illustrated fold seam 20 ("anaconda seam") is a preferred shape of the seam. The thicker region may be continuous from the barrier layer 4 all the way to the outside of the hollow article 2. However, the thicker region may also be present on the inside of the hollow article 2.

[0136] The sleeve 1 also typically has a circumferential region with a thicker region 21 due to a single overlap of the material of the sleeve 1. The thicker region 21 extends straight down the length of the sleeve 1.

[0137] The attachment of the sleeve 1 to the hollow article 2 is preferably done in a controlled orientation so that the thicker areas of the jacket of the hollow article 2 and the thicker areas 21 of the sleeve 1 are in different circumferential regions.

[0138] As shown in FIG. 16, thicker regions 21 of sleeve 1 may be adjacent to intertwined regions of hollow article 2.

[0139] In another alternative embodiment, the thicker region 21 of the sleeve 1 can be located anywhere beyond the thicker region of the hollow article 2. It is possible, but not necessary, for the thicker regions to even be diametrically opposite one another on the circumference of the hollow article 2. The positioning of the thicker region 21 of the sleeve 1 is not particularly precise, as long as it is within an angular range outside the angular range of the thicker region of the hollow article 2.

[0140] The ticker region of the hollow article 2 and the thicker region 21 of the sleeve 1 extend in the longitudinal direction of the hollow article 2. The respective thicker regions therefore do not intersect.

Claims

1. A method for disposing, on each of several hollow articles (2) open at both ends, an elastic sleeve (1) having a circumference in an unstretched state greater than the distance between the two diametrically opposed open ends of the hollow articles (2) and smaller than the circumference of the hollow articles (2) at their open ends, comprising: a method for fitting the sleeves, characterized in that the hollow articles (2), which are open at both ends, are held from the inside in a machine for fitting the sleeves (1), each sleeve (1) is stretched by a spreading action at least at its end facing the hollow article (2), and the sleeve (1) is placed on the hollow article (2) in the longitudinal direction of the respective hollow article (2) until the sleeve (1) covers the jacket surface of the hollow article (2) in the longitudinal direction of the hollow article (2) at both open ends, then the spreading action is removed, so that the two edges of the sleeve (1) covering the hollow article (2) protrude inwardly from the open edges of the hollow article (2) obliquely or perpendicularly, and then the two inward-protruding edges of the sleeve (1) are pressed onto the inner surface of the hollow article (2) and connected to the hollow article (2).

2. 2. The method according to claim 1, characterized in that each hollow article (2) is cylindrical and has, at both open ends, outwardly bulging edge regions, in particular two diametrically opposed edge regions extending outward along radii between which the cylindrical jacket section of the hollow article (2) extends.

3. 3. The method according to claim 1 or 2, characterized in that the inner jacket surface of each hollow article (2) is formed by a barrier material extending over the height of the hollow article (2) up to the two opening edges, and the outer jacket surface of the hollow article (2) is made of paper or cardboard material.

4. 4. The method according to claim 1, wherein a plurality of hollow articles (2) are simultaneously moved through the machine for fitting the sleeves (1), each of the hollow articles (2) resting on a retaining element (8) that contacts the jacket surface of the hollow article (2) on its inside, and after fitting the sleeves (1), the hollow articles (2) are further conveyed on the retaining element (8) to a device that presses one or both of the inwardly protruding edges of the sleeves (1) against the inner surface of the hollow article (2).

5. 5. The method according to claim 4, characterized in that before or during the pressing of the inwardly projecting edge of the sleeve (1) against the inner surface of the hollow article (2), a heating action is performed on the sleeve and the inner jacket surface of each hollow article (2), the sleeve (1) and the inner jacket surface being made of plastic and welded to each other.

6. 6. The method according to any one of claims 1 to 5, characterized in that the pressing of at least one of the two inwardly projecting edges of the sleeve (1) is carried out by attaching a sealing element that seals the opening of the hollow article (2).

7. 7. A method according to any one of claims 1 to 6, characterized in that each hollow article (2) is supported from the inside by a retaining element (8) across its cylindrical inner jacket area while the sleeve (1) is attached.

8. 8. The method according to any one of claims 1 to 7, characterized in that each hollow article (2) is supported from the inside by a retaining element (8) in at least one edge region of the outwardly bulging hollow article (2) while the sleeve (1) is attached.

9. 9. The method according to claim 1, wherein the stretching of the sleeve (1) is performed by means of a plurality of expansion elements protruding inward from the sleeve (1), the expansion elements contacting the sleeve (1) on the inside over a length equal to at least half the length of the hollow article (2), the plurality of expansion elements being present between the sleeve (1) and the hollow article (2) while the sleeve is in position, and the plurality of expansion elements being withdrawn from between the hollow article (2) and the sleeve (1) when the sleeve (1) is in its desired position on the hollow article (2).

10. 10. The method according to claim 1, wherein a counter pressure is applied to the outside of the hollow article (2), in particular to the edge region of the outwardly bulging hollow article (2), while at least one of the two inwardly protruding edges of the sleeve (1) is pressed and connected to the inner surface of the hollow article (2).

11. 11. A method according to claim 10, characterized in that the counter pressure is exerted by a holder (7) surrounding the hollow article (2).

12. 12. A method according to claim 11, characterized in that the counter pressure is exerted by an expandable, in particular inflatable or pumpable, element which contacts the outer edge region of the hollow article (2) only in the expanded state.

13. 10. The method according to any one of claims 1 to 9, characterized in that the attachment of the sleeve (1) to the hollow article (2) is performed in a controlled orientation, so that the thicker areas of the jacket of the hollow article (2) and the thicker areas (21) of the sleeve (1) are located in different circumferential regions.

14. 10. The method according to claim 1, wherein pressing at least one of the two inwardly protruding edges of the sleeve (1) against the inner surface of the hollow article (2) is performed using a transparent stamp, and a laser beam is directed at the area of ​​the sleeve (1) and the inner surface of the hollow article (2) so as to be connected via the transparent stamp.

15. 1. A device for fitting an outer sleeve (1) inside hollow articles (2) that are open at both ends, wherein the sleeve (1) is arranged longitudinally over each hollow article (2), the sleeve (1) covers the jacket surface of the hollow article (2) at both open longitudinal ends of the hollow article (2), and the two edges of the sleeve (1) covering the hollow article (2) preferably project obliquely or perpendicularly inward from the open edges of the hollow article (2), characterized in that the device comprises holding devices (9) or holders (7) each for holding one open hollow article (2), and a pressing element (8) for pressing the sleeve (1) inside the hollow article (2) at at least one end of the open hollow article (2), and relative movement between the pressing element (8) and the holding element (9) or holder (7) can be performed via the device.

16. 16. Apparatus according to claim 15, characterized in that it comprises means for welding the sleeve (1) inside the hollow article (2) open at both ends.

17. 17. Apparatus according to claim 15 or 16, characterized in that the apparatus comprises means for applying a counter pressure to the outside of the hollow article (2) opposite the pressing element (8).

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