Ultrasonic welding electrode and device for forming three-dimensional top of packaging body

Abstract

An apparatus is configured for shaping a three-dimensional top of a package. The apparatus comprises an anvil (21 ') having a three-dimensional shape. The anvil (21 ') is configured to receive a sleeve (11) of substrate material such that a front sleeve portion (11') of the sleeve (11) is positioned around at least a portion of the anvil (21 '). The apparatus further comprises a sonotrode (25) defining a three-dimensional cavity configured to receive the anvil (21 ') and the front sleeve portion (11') on the anvil (21 ') The sonotrode (25) is configured to apply mechanical vibrations to the front sleeve portion (11') on the anvil (21 ') via the three-dimensional cavity to cause permanent deformation of the front sleeve portion (11') to form the three-dimensional top.

Description

Technical Field

[0001] The present disclosure relates to the manufacture of packaging for food products and, in particular, to techniques for forming the top of the package body of such packaging. Background Art

[0002] In the food industry it is common practice to package food products in packages made from paper-based laminates comprising a core layer of paper or paperboard and one or more barrier layers, such as plastic.

[0003] A common type of package is manufactured by forming a tubular blank ("sleeve") of the above-mentioned paper-based laminate and sealing one end of the sleeve by a top of plastic material to form a bottle-shaped package. Typically, the top is formed directly on one end of the sleeve by injection molding. The top includes a neck that defines a pouring spout sealed by a cap and / or foil. The cap and / or foil can be provided by injection molding or in a separate installation step. The package is then transported to a subsequent filling station where it is filled with liquid product through the opposite open end of the package. After filling, the open end of the package is folded and sealed to form the final package. An example of this manufacturing technique is shown in WO2007 / 106006.

[0004] A variation is shown in WO2010 / 085182, in which a shoulder is formed at one end of a sleeve and then a top portion defining a neck is injection molded onto the shoulder. The shoulder is formed by folding the packaging material into the sleeve along crease lines to form radial folds. During the injection molding process, the upper edge of the radial folds is covered by the injected plastic material to fix the fold and avoid cracks forming inside the package. A related solution is shown in WO2004 / 041663.

[0005] In another variant shown in DE102005048821, a prefabricated pyramidal top of plastic material is attached to four foldable fins at one end of the sleeve. The shape of the fins is consistent with the pyramidal top, which is attached to the fins by horizontal welds along the corresponding sides of the pyramidal top.

[0006] Providing bottle-shaped packaging suitable for mass production is a common desire in the field of food packaging. Therefore, a robust technology for manufacturing bottle-shaped packaging with high production volume and low defect rate is required.

[0007] There is also a general desire to improve the recyclability of packaging by being able to reduce the use of different types of materials in the packaging. Utility Model Content

[0008] It is an object to at least partially overcome one or more limitations of the prior art.

[0009] One such object is to provide a simple and efficient technology for manufacturing bottle-shaped packaging bodies for food packaging.

[0010] One or more of these objects, as well as other objects that will emerge from the following description, are at least partly achieved by an apparatus and a sonotrode according to the following aspects, wherein embodiments are defined by the following clauses of the first aspect.

[0011] A first aspect, clause 1, is an apparatus for forming a three-dimensional top of a package. The apparatus comprises an anvil having a three-dimensional shape, the anvil being configured to receive a sleeve of a substrate material such that a front sleeve portion of the sleeve is positioned around at least a portion of the anvil. The apparatus further comprises a sonotrode defining a three-dimensional cavity, the three-dimensional cavity being configured to receive the anvil and the front sleeve portion on the anvil, the sonotrode being configured to apply mechanical vibrations to the front sleeve portion on the anvil via the three-dimensional cavity to cause permanent deformation of the front sleeve portion to form a three-dimensional top.

[0012] Clause 2. The apparatus of clause 1, wherein when the front sleeve portion is received in the three-dimensional cavity, a longitudinal center axis within the three-dimensional cavity is aligned with a longitudinal center axis of the anvil.

[0013] Clause 3. Apparatus according to any preceding clause, configured to press the anvil and the sonotrode towards each other with a predetermined force to compress the base material of the front sleeve portion during application of the mechanical vibration.

[0014] Clause 4. Apparatus according to any of the preceding clauses, wherein the three-dimensional cavity extends from an inlet opening into the sonotrode in a depth direction and is defined by a cavity wall surrounding the three-dimensional cavity in a circumferential direction.

[0015] Item 5. An apparatus according to Item 4, wherein the anvil includes a three-dimensional surface portion, the shape of which is consistent with the three-dimensional wall portion of the cavity wall, the three-dimensional wall portion is circumferential in the peripheral direction and defines a band-like contact surface for engaging with the three-dimensional surface portion of the anvil via the front sleeve portion.

[0016] Clause 6. An apparatus according to any one of clauses 4 to 5, wherein at least one of the anvil or the cavity wall includes a surface structure configured to cause a local change in the engagement force from the anvil and the cavity wall to the front sleeve portion.

[0017] Clause 7. The apparatus of Clause 6, wherein at least a subset of the deformation zones are configured to form a plurality of overlapping layers of the base material when the front sleeve portion is received in the three-dimensional cavity.

[0018] Clause 8. The apparatus of Clause 7, wherein the surface structure comprises elongated recesses configured to receive the plurality of overlapping layers of respective deformation regions of the at least one subset of deformation regions.

[0019] Clause 9. The apparatus of any one of Clauses 4 to 8, wherein the cavity wall includes a wall portion defining a shoulder, the wall portion being configured to deform at least a portion of the front sleeve portion into a shoulder of the package.

[0020] Clause 10. An apparatus according to any one of clauses 4 to 9, wherein the front end portion of the anvil includes a mounting structure for a neck element, the neck element including a tubular portion for defining an entry opening on the packaging body, wherein the mounting structure is arranged so that the neck element is at least partially located within the front sleeve portion when the front sleeve portion is located on the anvil.

[0021] Clause 11. The apparatus of any one of clauses 4 to 10, wherein the sonotrode comprises a first end face and a second end face, and a circumferential outer surface extending between the first end face and the second end face, wherein the three-dimensional cavity is formed in the first end face.

[0022] Clause 12. The apparatus according to any one of the preceding clauses, further comprising a deformation unit configured to engage the front sleeve portion on the anvil before the front sleeve portion is received in the three-dimensional cavity to cause a preliminary deformation of the front sleeve portion.

[0023] Clause 13. Apparatus according to any of the preceding clauses, wherein the base material of the front sleeve portion comprises a plastic material configured to be softened by the mechanical vibrations applied by the ultrasonic welding electrode and subsequently hardened in the absence of the mechanical vibrations to achieve the permanent deformation of the front sleeve portion.

[0024] Clause 14. Apparatus according to any of the preceding clauses, wherein the anvil is removably comprised in an elongated holder for receiving the sleeve of substrate material.

[0025] A second aspect is a sonotrode for use in the apparatus of the first aspect.

[0026] A third aspect is an anvil for use in the apparatus of the first aspect.

[0027] A fourth aspect is a sonotrode comprising a cavity defined by a three-dimensional cavity wall and configured to receive a three-dimensional anvil, the sonotrode being configured to apply mechanical vibrations to the three-dimensional anvil via the three-dimensional cavity wall.

[0028] Some embodiments of the device of the first aspect are described below, and these embodiments are also applicable to the second to fourth aspects.

[0029] When the front sleeve portion is received in the three-dimensional cavity, the longitudinal center axis of the three-dimensional cavity can be aligned with the longitudinal center axis of the anvil.

[0030] The three-dimensional cavity may be configured to fit tightly onto a front sleeve portion on the anvil.

[0031] The apparatus may be configured to press the anvil and the sonotrode toward each other with a predetermined force during application of the mechanical vibrations to compress the base material of the front sleeve portion.

[0032] The apparatus may be configured to apply a predetermined force to compress the substrate material by at least 10%, preferably at least 50%, during application of the mechanical vibrations.

[0033] The three-dimensional cavity may extend in depth direction from the entry opening into the sonotrode and be defined by a cavity wall surrounding the three-dimensional cavity in circumferential direction.

[0034] The anvil may comprise a three-dimensional surface portion having a shape conforming to the three-dimensional wall portion of the cavity wall, the three-dimensional wall portion being circumferential in a peripheral direction and defining a band-like contact surface for engagement with the three-dimensional surface portion of the anvil via the front sleeve portion.

[0035] When the anvil is received in the three-dimensional cavity, a three-dimensional surface portion of the anvil may be shaped to be locally parallel to a three-dimensional wall portion of a cavity wall.

[0036] At least one of the anvil or the cavity wall may include a surface structure configured to cause a localized change in the engagement force from the anvil and the cavity wall onto the front sleeve portion.

[0037] The surface structure may be arranged to extend in alignment with a deformation zone on the front sleeve part, the deformation zone being arranged to deform a local part of the front sleeve part when the front sleeve part is received in the three-dimensional cavity.

[0038] The surface structure may be elongated and extend in a depth direction when the anvil is received in the three-dimensional cavity.

[0039] At least a subset of the deformation regions may be configured to form a plurality of overlapping layers of the base material when the front sleeve portion is received in the three-dimensional cavity.

[0040] The surface structure may comprise elongated recesses configured to receive a plurality of overlapping layers of respective deformation regions of said at least one subset of said deformation regions.

[0041] The one or more deformation regions may be configured to form an elongated joint between adjacent edges of the base material when the front sleeve portion is received in the three-dimensional cavity.

[0042] The surface structure may comprise an elongate recess configured to receive the elongate joint when the front sleeve portion is received in the three-dimensional cavity.

[0043] The cavity wall may include a wall portion defining a shoulder configured to deform at least a portion of the front sleeve portion into a shoulder of the package.

[0044] The sonotrode may be configured to have an increasing radial thickness of material around the three-dimensional cavity in a depth direction along at least a portion of a wall defining the shoulder.

[0045] The three-dimensional cavity may have a non-circular cross-section transverse to the depth direction, wherein the radial protrusions are distributed around the inlet opening and are located at positions of maximum radial distance from a centerline of the three-dimensional cavity.

[0046] The front end portion of the anvil may include a mounting structure for the neck element, the mounting structure including a tubular portion for defining an access opening on the package body, wherein the mounting structure is arranged to position the neck element at least partially within the front sleeve portion when the front sleeve portion is located on the anvil.

[0047] The cavity wall may include a neck-defining wall portion configured to drive the front sleeve portion into engagement with a flange on the neck element when the front sleeve portion is received in the three-dimensional cavity.

[0048] The cavity wall may further include a bottom wall portion adjacent to the wall portion defining the neck, wherein the bottom wall portion is configured to receive the tubular portion of the neck element when the front sleeve portion is received in the three-dimensional cavity.

[0049] The bottom wall portion may be configured to be spaced apart from the tubular portion of the neck element when the front sleeve portion is received in the three-dimensional cavity.

[0050] The inlet opening may be defined by a tapered wall portion that slopes into the three-dimensional cavity to receive the front sleeve portion within the three-dimensional cavity.

[0051] The sonotrode may be arranged with the three-dimensional cavity facing upwards relative to gravity.

[0052] The sonotrode may include a first end face and a second end face, and a circumferential outer surface extending between the first end face and the second end face, wherein the three-dimensional cavity is formed in the first end face.

[0053] The circumferential outer surface may have a convex shape between the first end surface and the second end surface.

[0054] The second end surface may be configured for mechanical attachment to the generator unit to receive mechanical vibrations.

[0055] The apparatus may include a generator unit configured to generate mechanical vibrations and to transfer the mechanical vibrations to the sonotrode.

[0056] The generator unit may be configured to generate mechanical vibrations having a frequency given by a distance between the first end surface and the second end surface.

[0057] The circumferential outer surface of the sonotrode may be shaped to induce mechanical vibrations when the front sleeve portion is received in the three-dimensional cavity to cause the cavity wall to vibrate locally substantially perpendicular to the front sleeve portion on the anvil.

[0058] At least one channel may be defined in the sonotrode to extend from a first opening in the bottom of the three-dimensional cavity to a second opening in the circumferential outer surface.

[0059] The at least one channel may extend away from the first end surface.

[0060] The apparatus may comprise a deformation unit configured to engage the front sleeve part on the anvil to cause a preliminary deformation of the front sleeve part before the front sleeve part is received in the three-dimensional cavity.

[0061] The deformation unit may comprise an engagement element for engaging with a corresponding deformation zone on the front sleeve part, the corresponding deformation zone being arranged to facilitate a local deformation of the front sleeve part when the front sleeve part is received in the three-dimensional cavity.

[0062] The engagement elements may be configured to be biased towards the respective deformation zones.

[0063] The deformation unit may be operable to slide the engagement element into engagement with the corresponding deformation zone.

[0064] The deformation unit may be configured to synchronously engage the engagement elements with the respective deformation zones.

[0065] The deformation unit may be arranged in front of the three-dimensional cavity to engage the front sleeve portion when the front sleeve portion relatively moves toward the three-dimensional cavity.

[0066] The deformation unit may be spaced apart from the sonotrode and operable independently of the sonotrode, the apparatus further comprising a transport device for moving the elongated holder with the sleeve from the deformation unit to the sonotrode.

[0067] The base material of the front sleeve portion may include a plastic material configured to be softened by mechanical vibrations applied by the sonotrode and subsequently hardened in the absence of mechanical vibrations to achieve permanent deformation of the front sleeve portion.

[0068] The base material may comprise a sheet, and the plastic material may be provided on at least one side of the sheet.

[0069] The base material may be compressible.

[0070] The three-dimensional cavity can form a blind hole in the sonotrode.

[0071] The sonotrode may be a solid block of material.

[0072] The anvil may be removably included in an elongated holder for receiving a sleeve of base material.

[0073] The apparatus may further include a translation device connected to the sonotrode and operable to linearly move the sonotrode relative to the anvil.

[0074] Other objects, features, embodiments, aspects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1A is a schematic diagram of an exemplary manufacturing process according to an embodiment using a first type of blank, Figure 1B and Figure 1C is a plan view of an alternative blank used in the exemplary manufacturing process, and Figure 1D is a side view of a neck component used in this manufacturing process.

[0076] Figure 2A is a plan view of an exemplary first type blank, Figure 2B is a perspective view of a sleeve with a deformed front sleeve portion, Figure 2C is a three-dimensional image of the packaging body produced by the manufacturing process, Figure 2D yes Figure 2C A cross-sectional view of the packaging body, Figure 2E yes Figure 2D an enlarged view of a portion of Figure 2F It is a cross-sectional view of the blank material.

[0077] Figure 3 is a schematic diagram of an example station for manufacturing packages according to various embodiments.

[0078] Figure 4A is Figure 3 A cross-sectional view of an exemplary top forming station during operation in a station of Figure 4B is a perspective view of an exemplary anvil for use in a top forming station, Figure 4C and Figure 4D is a cross-sectional view of a blank material positioned on an anvil; FIG. 4E to FIG. 4G yes Figure 4B Side, cross-sectional and top plan views of the center anvil.

[0079] Figure 5A and Figure 5B is a perspective view of an example sonotrode used in a top forming station, Figure 5C is a plan view of the ultrasonic welding electrode. Figure 5D is a side view of the ultrasonic welding electrode. Figure 5E yes Figure 5C Cross-sectional view of the ultrasonic welding electrode, Fig. 5F is relative to Figure 5D Side view of the sonotrode displaced 45° about its longitudinal axis, Figure 5G yes Fig. 5F Cross-sectional view of the ultrasonic welding electrode.

[0080] Figure 6 It is related to the deformation unit Figure 4B A cross-sectional view of an anvil in FIG. 1 , wherein the anvil is provided with a sleeve and a neck element.

[0081] Fig. 7A shows a vibration cycle of an exemplary sonotrode, and Figure 7B yes Fig. 7A Schematic representation of the perimeter of the cavity in the sonotrode at different stages during the vibration cycle.

[0082] Figure 8 is a schematic diagram of an alternative station for manufacturing packages according to various embodiments. DETAILED DESCRIPTION

[0083] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments are shown. Indeed, the subject matter of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure may satisfy applicable legal requirements.

[0084] Where possible, any advantage, feature, function, device and / or operational aspect of any embodiment described and / or contemplated herein may be included in any other embodiment described and / or contemplated herein, and / or vice versa. In addition, where possible, unless otherwise expressly provided, any term expressed in the singular herein is also intended to include the plural form and / or vice versa. Therefore, the term "a" and / or "one" should mean "at least one" or "one or more", even if the phrase "one or more" or "at least one" is also used here. The terms "several", "plural" and "multiple" are intended to imply that two or more elements are provided. The term "and / or" includes any and all combinations of one or more related listed elements. Although the terms first, second, etc. may be used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0085] For the sake of brevity and / or clarity, well-known functions or constructions may not be described in detail. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs.

[0086] Like reference numerals refer to like elements throughout.

[0087] The present disclosure relates to a technology for producing a package for food. The technology involves using welding to shape a three-dimensional (3D) top of a package. Welding involves transmitting mechanical vibrations to a packaging material to form a fusion or weld between different parts of the packaging material. The weld is produced by friction heating caused by mechanical vibrations. The mechanical vibrations can be in the ultrasonic range, such as 15-40kHz, resulting in so-called ultrasonic welding. The mechanical vibrations are transmitted to the packaging material by a so-called sonotrode (also called a horn). The packaging material is joined between the sonotrode and anvil (also called a nest) under pressure. The anvil has no active vibration. Traditionally, the sonotrode and the anvil are configured to join along a line, thereby producing a one-dimensional weld. The present disclosure is based on the following basic understanding, that at least a portion of the top can be produced by simultaneous three-dimensional welding, in particular by using a sonotrode having a 3D surface, which is configured to transmit mechanical vibrations to the packaging material when it abuts against an anvil with a shape consistent with the 3D surface of the sonotrode. 3D welding is capable of forming welds of any 3D shape and any size. As used herein, 3D surface includes one or more curved or non-planar surface parts in a three-dimensional Euclidean coordinate system. For example, in a bottle-shaped package, the top can have the general shape of a dome as a 3D object. This novel three-dimensional welding (3DW) technology allows the top or at least a portion thereof to be formed in a single welding operation, which provides high yield and production reliability. The packaging material can be made of paper or paperboard, with a thermoplastic material thereon to melt during the welding operation and then harden. Three-dimensional welding makes it possible to manufacture at least a portion of the top of the packaging material forming the main package. Compared with the top being fully by plastic material injection molding or otherwise produced, this will reduce the amount of plastic material in the package.

[0088] Figure 1AFrom left to right, an overview of the operation steps for producing a packaging body according to an embodiment is shown. The process shown starts from a sheet or blank 10 of packaging material, also referred to herein as a base material. The sheet 10 is rectangular and includes opposite end edges 110 connected by side edges 111. In the example shown, the end at one end edge 110 of the sheet 10 has a predetermined deformation zone 10', which can achieve a controlled and clear deformation of the base material during the production process of the packaging body. In some embodiments, the corresponding deformation zone 10' includes one or more crease lines or folding lines. The crease line acts as a hinge for folding the base material and can be implemented as a depression in the base material. If a depression is formed on one side of the sheet, it is conducive to folding on that side. The crease line is arranged so that the base material is folded onto itself in 3D welding (operation step S3). In some embodiments, the deformation zone 10' is omitted. In operation step S1, the sheet 10 is formed into a sleeve or collar 11 by overlapping and joining the edge portions at the side edges 111, such as by gluing or welding. The overlapping edge portions form a longitudinal seam (not shown) extending along the sleeve 11. The sleeve 11 is a cylinder having any cross-section, whether circular or non-circular. The sleeve 11 includes a front portion 11' ("front sleeve portion"), which will be formed into a top during the production of the packaging body 13. If present, the deformation zone 10' is located in the front sleeve portion 11'. The remainder of the sleeve 11 forms a main body 11", which extends from the front sleeve portion 11' to the opposite end of the sleeve 11. In operation step S2, the front sleeve portion 11' undergoes preliminary deformation or "preforming" to produce a deformed sleeve 12. Preforming is optional and its purpose is to give the front sleeve portion 11' a shape suitable for the subsequent operation step S3. Typically, as shown in the figure, preforming changes the shape of the front sleeve portion 11' from a cylinder to a truncated cone. Preforming can improve the ability of operation step S3 to produce a top with a consistent shape, thereby potentially reducing the defect rate. Preforming can also ensure that the neck element (see below) is placed in operation step S3. The preforming can be accomplished by mechanically engaging a deformation unit (not shown) with the front sleeve portion 11' to bend the base material. For example, preforming can involve folding the base material around a crease line. In operation step S3, the deformed sleeve 12 is subjected to the above-mentioned 3D welding to produce a packaging body 13 having a top 13' of a desired 3D shape. As will be further explained in detail below, in operation step S3, as the front sleeve portion 11' is deformed into the desired shape, the base material is folded onto itself, and the overlapping portions are melted together by 3D welding to fix the shape of the front sleeve portion 11', thereby producing a top 13'.

[0089] like Figure 1AAs shown, prefabricated neck element 14 can be provided to operation step S3, integrated in top 13 ' by 3D welding. Neck element 14 defines access opening 14a, and consumer enjoys food through this access opening. Neck element 14 can include a cap or foil of sealing access opening 14a. Alternatively, in a subsequent operation step (not shown), a cap or foil can be attached to cover access opening 14a. Then package 13 is transferred to a filling station (not shown), where food is filled in package 13 by its open end facing upward, and afterwards, as known in the art, the open end facing upward is sealed.

[0090] An example of a neck member 14 is Figure 1D As shown. The neck element 14 includes a tubular portion 14" defining an entry opening 14a. The tubular portion 14" may include external threads (not shown) for engaging with a cap. As described above, the cap may or may not be included in the neck element 14. The neck element 14 also includes a circumferential flange 14' protruding from the tubular portion 14". The flange 14' defines an attachment surface that engages with a base material in the packaging body 13 during or after 3D welding.

[0091] Many variations are possible. If preforming is omitted, 3D welding is performed directly on the sleeve 11. The prefabricated neck element 14 does not need to be attached by 3D welding, but can be attached to the packaging body 13 in a separate operation step after 3D welding. Alternatively, the neck element can be formed and attached by injection molding after 3D welding.

[0092] Furthermore, the deformation zone 10' need not include crease lines. Figure 1B A sheet 10 is shown having a deformation zone 10' in the form of a cut. Each cut 10' is defined by a boundary edge of a base material. When the front sleeve portion 11' is deformed in operation step S3 and fused together by 3D welding, the shape of the respective cuts 10' is such that their boundary edges are aligned and in contact with each other. In order to ensure a strong and durable seal between the boundary edges, a thermoplastic material strand 10" may be provided on at least a portion of the boundary edge around the respective cut 10'. The boundary edge is preferably curved (non-linear) to ensure a durable seal and avoid wrinkle formation. In certain embodiments, as shown, the boundary edge is convex.

[0093] Figure 1C A sheet is shown with a deformation zone 10' in the form of a cutout covered by a film or web of thermoplastic material. The provision of a film potentially relaxes the need for correct alignment between the cutout boundary edges during the 3D welding process, since as the front sleeve portion 11' is deformed in operation step S3, the film will be folded over the base material, thus covering a surface area greater than that of the base material. Figure 1B 10". Therefore, Figure 1CThe deformation zone 10' in the embodiment may allow the substrate material to overlap when the cutout 10' is closed by deformation in operation step S3.

[0094] It is also conceivable that the deformation zone 10' comprises Figures 1A to 1C Any combination of variations in the , such as crease lines and cuts.

[0095] Figure 2A A detailed example of a sheet 10 having a deformation zone 10' formed by crease lines that promote a predetermined bending pattern of the base material in the corresponding deformation zone 10' is shown. The corresponding deformation zone 10' includes a first set of crease lines 10a that promote bending in one direction, and a second set of crease lines 10b that promote bending in the opposite direction. Specifically, when the sheet 10 is formed into a sleeve 11, the first set of crease lines 10a promotes the formation of an outward fold protruding from the inside of the sleeve 11, while the second set of crease lines 10b promotes the formation of an inward fold protruding into the inside of the sleeve 11. The crease lines 10a, 10b can be linear, as shown in the figure. The first set of crease lines 10a and the second set of crease lines 10b can be arranged to define a corresponding triangle, such as an isosceles triangle, whose base is at the end edge 110, and therefore at the front edge of the front sleeve portion 11'. The triangles of each deformation zone 10' are aligned with each other so that one triangle is arranged inside another triangle. In the example shown, the crease line 10a is arranged around the crease line 10b, although the opposite is also possible. In a variant, the apex of the triangle is removed, forming a truncated triangle, which is believed to reduce the formation of wrinkles on the top. Such a truncated triangle is included in the deformation sleeve 12, such as Figure 2B As shown, the crease line 10a forms an outward fold in the front sleeve portion 11' and the crease line 10b forms an inward fold. Figure 2C A package 13 is shown, which consists of Figure 2B The deformed sleeve 12 is made in the middle. The body 11 "is not affected by the 3D welding, but the front sleeve part 11 'has been formed into a top part 13' with a substantially smooth outer surface. The base material has been folded onto itself through the crease line in the deformation zone 10' and fused together. Figure 2C The dotted lines in the individual deformation zones 10' in the figure indicate where the inward folds (crease lines 10b) meet in the joint 1' inside the package body 13. By melting the overlapping substrate materials in the deformation zones 10', a strong and durable formation of the top 13' is achieved. In addition, the deformation zones 10' are flat in the top 13 both on the outside and on the inside of the package body. If desired, a flat inner surface can improve food safety and facilitate sterilization. Figure 2CIt is also shown that 3D welding will generally also deform the front sleeve portion 11' outside the deformation zone 10'. In the example shown, a slightly protruding panel 13' is formed on the side of the top 13'. The deformation zone 10' is different from the rest of the front sleeve portion 11' because it is formed to accommodate the base material that becomes redundant when the front sleeve portion 11' is deformed into a dome shape. Figure 1B and Figure 1C In the example of , excess substrate material is at least partially cut away. Figure 2A In the example above, excess base material folds over on itself in a controlled manner.

[0096] Figure 2D Shows Figure 2C A cross section of the package body 13 taken along the 2D direction, and Figure 2E yes Figure 2D An enlarged view of the middle area 2E. As shown in the figure, the dome-shaped top 13' is formed as a neck NP extending from the main body 11" to the packaging body 13. The neck NP is formed by a neck element 14. The top 13' includes a band-like shoulder SP adjacent to the main body 11" and an attachment portion AP located at the distal end of the top 13'. The attachment portion AP is attached to the flange 14' of the neck element 14. In the illustrated example, the cap 14' is engaged with the tubular portion 14" of the neck element 14 by engaging the internal thread of the cap 14' with the external thread on the tubular portion 14' to seal the entry opening 14a defined by the tubular portion 14". As is well known in the art, the neck element 14 also includes an anti-tamper element 14", which breaks when the cap 14'" is unscrewed from the tubular portion 14".

[0097] Figure 2F 1 is a cross-sectional view of the base material 1 in the sheet 10. The base material 1 is ductile so that it can be reshaped by applying force. In some embodiments, the base material 1 is compressible. This improves the performance of 3D welding. In the example shown, the base material has a thickness T0 and includes a core 1A and a covering surface 1B of a plastic material on both sides of the core 1A. The covering surface 1B may include any plastic material or a combination of plastic materials that softens due to mechanical vibrations applied during 3D welding and then hardens in the absence of mechanical vibrations. For example, the covering surface 1B may include a thermoplastic material. Depending on the bending mode in the deformation zone 10', it may be sufficient to provide a covering surface 1B only on one side of the core 1A. It is also conceivable that one of the covering surfaces 1B is optimized for 3D welding, while the other covering surface 1B is optimized for another purpose, such as with respect to barrier properties. In some embodiments, the core 1A is or includes a fiber base material, such as one or more layers of paper or cardboard. Other materials or combinations of materials may define the core 1A or be part of the core 1A, including plastic materials. If the core 1A is made of plastic material, the covering surface 1B may be omitted.

[0098] Figure 3 is a side view of a station or machine 2 for producing packages 13 according to a non-limiting example. The station 2 comprises an indexing device 300, a neck loading device 301, a sleeve loading device 302, a top forming device 303 and an unloading device 304. The neck loading device 301 is configured to receive a neck element 14, as indicated by arrow A1, and arrange the neck element 14 on the indexing device 300. The sleeve loading device 302 is configured to receive an incoming sleeve 11, as indicated by arrow A2, and arrange the sleeve 11 on the indexing device 300. The top forming device 303 is configured to reshape the sleeve 11 and attach the neck element 14 to form the package 13. The unloading device 304 is configured to remove the packages 13 from the indexing device 300 and provide them for downstream processing, as indicated by arrow A4.

[0099] The loading devices 301 , 302 and the unloading device 304 may be configured in many different ways to perform their respective functions and will not be described in detail. Some non-limiting examples are found in WO2007 / 106006.

[0100] The indexing device 300 includes an elongated holder or arm 21 attached to or otherwise coupled to a rotatable member 22 (also referred to as a wheel or spindle wheel). Each arm 21 includes an internal tool 21' corresponding to the anvil described above. In some embodiments, the anvil 21' is removably attached to the arm 21 to facilitate replacement of the anvil 21'. The anvil 21' is subject to wear and may need to be replaced. In addition, an anvil 21' and a corresponding ultrasonic welding electrode 25 having another 3D shape can be installed to produce a package 13 with a different 3D shape of the top 13.

[0101] The elongated arms 21 protrude radially from the wheel 22 and are equidistantly distributed around the wheel 22. In the illustrated example with four arms 21, each arm is arranged at right angles to its adjacent arm. A drive unit 23 is connected to the wheel 22 and is operable to rotate the wheel 22 as indicated by arrow A0. The drive unit 23 may be an electric motor capable of precise angular positioning, such as a servo motor or a stepper motor. The drive unit 23 is operable to intermittently rotate or index the wheel 22 and thus the arms 21 to four different angular positions. The drive unit 23 stops at the corresponding angular positions. These positions are indicated by Figure 3 The Roman numerals in the dotted circle indicate: Position I is the first loading position, in which the anvil 21' is aligned with the neck loading device 301. Position II is the second loading position, in which the anvil 21' is aligned with the sleeve loading device 302. Position III is the processing position, in which the anvil 21' is aligned with the top forming device 303. Position IV is the unloading position, in which the anvil 21' is aligned with the unloading device 304.

[0102] The arrangement of four arms 21 with corresponding anvils 21' satisfies a high throughput of station 2 since it enables four operations to be performed simultaneously: loading the neck element 14 onto the anvil 21' at device 301, loading the sleeve 11 onto the anvil 21' at device 302, processing the sleeve 11 on the anvil 21' at device 303, and unloading the package 13 from the anvil 21' at device 304.

[0103] The arm 21 extends from the wheel 22 in a common plane which forms a plane of rotation of the arm 21. Depending on the embodiment, the plane of rotation may be vertical or horizontal.

[0104] In a variant not shown, the neck loading device 301 is configured to place the neck element 14 on the anvil 21' when the anvil 21' is moved between positions IV and I or between positions I and II. In another variant, the neck loading station 301 is omitted and the neck is attached or otherwise formed on the packaging body 13 downstream of the unloading device 304.

[0105] The top forming device 303 includes an external tool 25, which is movable relative to the anvil 21' when in position III. The external tool 25 is the ultrasonic welding electrode mentioned above. In the example shown, the ultrasonic welding electrode 25 is linearly movable between a rest position and an operating position, as shown by the double-ended arrow A3. In the rest position, the ultrasonic welding electrode 25 is spaced apart from the anvil 21'. In the operating position, the ultrasonic welding electrode 25 is arranged to surround the anvil 21'. The top forming device 303 includes an actuator or translation device 26, which is connected to the ultrasonic welding electrode 25 and is operable to impart movement thereto between the rest position and the operating position. As shown in dotted lines, a cavity 25' is defined in the ultrasonic welding electrode 25 to receive the anvil 21'. Since the neck 14 and the sleeve 11 are arranged on the anvil 21', the ultrasonic welding electrode 25 surrounds both the neck 14 and the front sleeve 11' ( Figure 1A , Figure 2B ). The dimensions of the sleeve 11 are such that the inner side of the sleeve 11 is at least partially in contact with the arm 21, so that it falls off the arm 21 when the arm 21 is in position III. The cavity 25' defines the above-mentioned 3D surface. In its operating position, the sonotrode 25 is operable to reshape the front sleeve part 11' into the top 13' of the packaging body 13, while also attaching the neck element 14 to the front sleeve part 11'.

[0106] The top forming device 303 also includes a supply device 27A for generating a power supply signal of a predetermined frequency, and a conversion unit 27B configured to convert the power supply signal into mechanical vibration. The supply device 27A and the conversion unit 27B together define a generator unit, which is configured to generate mechanical vibrations and transmit the mechanical vibrations to the ultrasonic welding electrode 25. The ultrasonic welding electrode 25 is mechanically attached to the conversion unit 27B to receive the mechanical vibrations. The conversion unit 27B can be a conventional configuration and includes a transducer for converting the power supply signal into mechanical vibrations. The mechanical vibrations can be generated by one or more piezoelectric crystals in the transducer. As known in the art, the conversion unit 27B can also include a booster or an amplitude coupler, which is configured to limit the amplitude of the mechanical vibrations transmitted to the ultrasonic welding electrode by amplifying or attenuating the amplitude of the mechanical vibrations generated by the transducer.

[0107] In the example shown, the deformation unit 28 is arranged to be located in front of the cavity 25'. The deformation unit 28 is configured to perform the above-mentioned preliminary deformation ("preforming") of the front sleeve part 11'. The deformation unit 28 is arranged to be movable together with the sonotrode 25 to engage and preform the front sleeve part 11' when the sonotrode 25 moves towards the anvil 21' and moves on the anvil 21'. As shown, the deformation unit 28 can be attached to the sonotrode 25. Alternatively, the deformation unit 28 can be isolated from mechanical vibrations, for example by being attached to a separate holder (not shown), which is moved in unison with the sonotrode 25 by the actuator 26 or another actuator (not shown).

[0108] Figure 3 The top forming device 303 in is an example of an apparatus for forming a three-dimensional (3D) top 13' of a package body 13. The apparatus includes an anvil 21' having a 3D shape. The anvil 21' is configured to receive a sleeve 11 of a base material 1 so that a front sleeve portion 11' is positioned around at least a portion of the anvil 21'. The apparatus also includes an ultrasonic welding electrode 25, which defines a 3D cavity 25', which is configured to receive the anvil 21' and the front sleeve portion 11' located on the anvil 21'. The ultrasonic welding electrode is configured to apply mechanical vibrations to the front sleeve portion 11' on the anvil 21' via the 3D cavity 25' to cause permanent deformation of the front sleeve portion 11', thereby forming a 3D top 13'.

[0109] like Figure 3 As shown, the sonotrode 25 can be arranged with the cavity 25' facing upwards relative to gravity. This can reduce the risk of debris that may be formed during operation of the top forming device 303 being spread on the station 2. The cavity 25' facing upwards also facilitates the controlled removal of liquid or debris that may enter or form in the cavity 25' during operation of the top forming station 303. The controlled removal of debris may be important to ensure a consistent quality of the produced packages 13.

[0110] In some embodiments, Figure 3 As shown, the cavity 25' forms a blind hole in the sonotrode 25. The blind hole has an axial extent limited by a bottom surface. The cavity 25' in the form of a blind hole allows the sonotrode 25 to include solid material between the cavity 25' and the conversion unit 27B, which is believed to improve the proper transmission of mechanical vibrations to the walls of the cavity 25'.

[0111] Station 2 need not be configured to rotate the respective arm 21 between devices 301 - 304 , but may be configured in other ways to move arm 21 between devices 301 - 304 , for example along a linear path.

[0112] It may be noted that the station 2 may alternatively be designed so that the sonotrode 25 is stationary, while the anvil 21 ′ on which the sleeve 11 is mounted moves between a stationary position spaced from the sonotrode 25 and an operative position engaged with the sonotrode 25 .

[0113] Figure 4A is a cross-sectional view of an exemplary sonotrode 25 engaged with an exemplary anvil 21'. The anvil 21' and the sonotrode 25 may include Figure 3 The anvil 21' and the ultrasonic welding electrode 25 can both be made of metal. The anvil 21' is attached to the arm 21. Before the anvil 21' is received in the cavity 25', for example by Figure 3 In the sleeve loading device 302, the sleeve 11 has been slid onto the anvil 21 '. In addition, the neck element 14 has been Figure 3 The neck loading device 301 in is attached to the anvil 21' and is received in the cavity 25'. The anvil 21' and the ultrasonic welding electrode 25 are forced into engagement with each other by a force F, as shown by the opposing block arrows, while at least a portion of the front sleeve portion 11' is engaged between the anvil 21' and the ultrasonic welding electrode 25. The force F is applied during the welding process, and optionally before the welding process. The force F is suitable for deforming the front sleeve portion 11' into a top of a predetermined shape. The force F may be suitable for compressing the substrate material by at least 10%, for example at least 50%, compared to the thickness T0 of the unloaded substrate material (see Figure 2F ). In other embodiments, the compression may be at least 20%, 30%, 40%, 60% or 70%. In some embodiments, the force F is at least 500N, for example at least 1000N.

[0114] The surface portions of the anvil 21 'and the cavity have complementary 3D shapes. The shape of the anvil 21 'is consistent with the cavity 25' of the sonotrode 25, so that the front sleeve portion 11 'arranged on the anvil 21 'fits tightly in the cavity 25'. As used herein, "snug fit" means that at least when the force F is applied, the front sleeve portion 11 'is in contact with the anvil 21 'and the cavity wall 250 around the entire circumference of the front sleeve portion 11 '.

[0115] The three-dimensional view of the anvil 21 ' is as follows Figure 4B As shown, the side view is Figure 4E shown. Figure 4F Shows along Figure 4E A cross section of the anvil 21' taken along the 4F direction. Figure 4G is a plan view of the protruding end (free end) of the anvil 21'. Two stereoscopic views of the ultrasonic welding electrode 25 at different angles are shown in FIG. Figure 5A and Figure 5B shown. Figure 5C is a plan view of an inlet opening 250 ′ of a cavity 25 ′ in a sonotrode 25 . Figure 5D and Fig. 5F Different sides of the sonotrode 25 are shown. Figure 5D and Fig. 5F Rotate 45° around its longitudinal center axis. Figure 5E is along Figure 5D A cross-sectional view taken along the 5E direction, and Figure 5G is along Fig. 5F Cross-sectional view taken along the 5G direction.

[0116] The anvil 21' has a longitudinal central axis or centerline CS1, such as Figure 4F As shown, the cavity 25' has a longitudinal central axis or centerline CS2', as shown Figure 5E and Figure 5G When the anvil 21' and thus the front sleeve portion 11' are received in the cavity 25', these center axes CS1, CS2' are aligned to coincide.

[0117] In the illustrated example, the cavity 25' in the sonotrode 25 is defined by a peripheral cavity wall 250 and a bottom wall 250b ( Figure 5E , Figure 5G The cavity wall 250 surrounds and limits the cavity 25' in the peripheral direction, and the cavity 25' is Figure 4A , Figure 5E , Figure 5G ) has an axial extent from the inlet opening 250' to the bottom wall 250b. The cavity wall 250 includes a 3D wall portion 250a ( Figure 4A , Figure 5E , Figure 5G), which is configured to engage the 3D surface portion 211 of the anvil 21' via the front sleeve portion 11'. The shapes of the 3D wall portion 250a and the 3D surface portion 211 are consistent with each other to achieve the above-mentioned tight fit of the front sleeve portion 11'. Figure 4A As shown, the 3D wall portion 250a defines a band-like contact surface for engaging with the 3D surface portion 211 of the anvil 21' via the front sleeve portion 11'. The contact surface is band-like in that it spans the entire circumference of the cavity 25' in the peripheral direction and has a certain extent in the depth direction DD.

[0118] In some embodiments, in order to achieve a tight fit, when the anvil 21 'is received in the cavity 25', the 3D surface portion 211 and the 3D wall portion 250a are formed to be partially parallel. In this case, "partially parallel" means that at corresponding positions on the surface portion 211 and the wall portion 250a, the tangent plane of the surface portion 211 and the tangent plane of the wall portion 250 are substantially parallel, for example within the range of ±10° or ±5°.

[0119] By comparison Figure 2C and Figure 4B As can be seen, the shape of the 3D surface portion 211 of the anvil 21' provides the 3D shape of the top portion 13' including the protruding panel 13". Similarly, as shown in FIG. Figure 5E and Figure 5G As shown, the shape of the cavity wall 250 in the cavity 25 ′ of the sonotrode 25 provides a 3D shape including the top 13 ′ of the protruding plate 13 ″.

[0120] The free end of the anvil 21' includes a mounting structure 212 for receiving the neck element 14. In the illustrated example, the mounting structure 212 is defined to engage with the neck element 14 in a form-fitting manner so that the neck element 14 is retained on the free end of the anvil 21' during its passage from the neck loading device 301 to the top forming device 303 ( Figure 3 ).like Figure 4A and Figure 4B As shown, the anvil 21' can be releasably included in the arm 21 by using a bolt 220 and a washer 221. At the end opposite to the mounting structure 212, the anvil 21' includes a mounting hole 214 ( Figure 4F ), the assembly hole is configured to receive the axially protruding arm member 21a ( Figure 4A The anvil 21 ′ defines a through hole 213 which is arranged to cooperate with an internally threaded mounting hole in the protruding arm member 21 a for engagement with an external thread on the bolt 220 .

[0121] exist Figure 4BIn the example of, the anvil 21' also includes a surface structure 210, which is configured to cause a local change in the engagement force of the anvil 21' and the cavity wall 250 on the front sleeve portion 11'. This means that the engagement force is modified compared to the alternative case where the surface structure 210 is omitted. In the illustrated example, the corresponding surface structure 210 is a restricted area on the 3D surface portion 211 of the anvil 21'. In some embodiments, when the sleeve 11 is pressed into engagement with the cavity wall 250, the surface structure 210 is positioned to coincide with or align with the deformation zone 10' on the front sleeve portion 11'. In some embodiments, the surface structure 210 can be designed to locally increase the engagement force to enhance friction, thereby enhancing the heat generation caused by mechanical vibration. In other embodiments, the surface structure 210 can be designed to achieve an engagement force that is substantially the same as the engagement force achieved by other parts of the 3D surface portion 211.

[0122] In some embodiments, Figure 4A As shown, the surface structure 210 is elongated and is configured to extend in the depth direction DD of the cavity 25 when the anvil 21' is received in the cavity 25'. Such an elongated surface structure 210 may be relevant when the deformation zone 10' also has an extent in the depth direction DD, which is Figures 1A to 1C and FIG. 2A to FIG. 2C The situation of the deformation zone 10' is shown.

[0123] Figure 4C is along Figure 4B 2 '. In addition, the base material 1 is overlaid with a dotted line to illustrate how the surface structure 210 coincides with the deformation zone when the front sleeve portion 11' is pressed between the anvil 21' and the cavity wall 250. In this example, the two separated edges of the base material 1 will be joined together at the open joint 1'. Such a joint 1' can be formed by using a sheet 10 with a cutout, for example, as Figure 1B or Figure 1C As shown. It can be appreciated that the joint 1' will have an elongated extent in the depth direction DD of the cavity 25'. In the example shown, the surface structure 210 is raised to define a protrusion or ridge, which is arranged to carry the base material 1 at the joint 1'. The protrusion 210 will locally increase the engagement force between the anvil 21' and the cavity wall 250, thereby locally increasing the impact of mechanical vibrations. This local increase can help ensure that the joint 1' is properly and permanently melted by the heat from the mechanical vibrations. The height T2 of the protrusion 210 relative to the surrounding surface can be sized relative to the thickness T0 of the base material 1 to achieve appropriate local heating. In some embodiments, the ratio T2:T0 is greater than 0.1-0.3 and less than 0.7-0.9.

[0124] Figure 4Dis along Figure 4B Another example view of a cross section taken in the direction 4 of the anvil 21'. Here, the base material 1 is folded into multiple overlapping layers in the deformation zone, where the inner layer includes an open joint 1' where different parts of the base material meet. This joint 1' is permanently melted by the heat from the mechanical vibrations. Figure 4D In this case, three layers are stacked on top of each other. For example, this stacking of layers is made up of Figure 2A and Figure 2B The deformation zone shown is formed. In the example shown, the surface structure 210 defines a recess or tray, which is arranged to receive the stacked layers of substrate material 1 and the joint 1'. The depth T2 of the recess 210 can be sized to obtain the desired bonding force between the anvil 21' and the cavity wall 250. In the absence of the recess 210, the bonding force may become too large due to the stacked layers. In some embodiments, the depth T2 is equal to or less than the difference between the height T1 of the stacked layer and the thickness T0 of the substrate material. This will result in the bonding force on the substrate material in the stacked layer being approximately equal to or greater than the bonding force on the substrate material around the recess 210. In some embodiments, T2 = T1-T0·(1+α), where α is greater than 0.1-0.3 and less than 0.7-0.9.

[0125] The anvil 21' may also include a dedicated surface structure for the longitudinal seam of the sleeve 11. According to the embodiment, the surface structure may be a protrusion or a depression. Examples of such surface structures are as follows: Figure 4E As shown in the figure 210'.

[0126] The surface structures 210, 210' on the anvil 21' may be supplemented or replaced by similar surface structures on the cavity wall 250 in the sonotrode 25. However, it is currently considered beneficial to provide the surface structure 210 only on the anvil 21'. If the surface structures are provided on the cavity wall 250 in the sonotrode 25 as depressions or protrusions, the corresponding surface structures may be observed on the outside of the top 13' of the resulting package 13. This may be undesirable from an aesthetic point of view. The top 13' is also generally required to have a smooth outer surface to reduce the adhesion of dust and stains. The smooth outer surface of the top 13' is achieved by having a smooth 3D wall portion 250a in the cavity 25'. In addition, providing the surface structure on the cavity wall 250 in the sonotrode 25 may affect the vibration mode of the sonotrode 25. Therefore, providing the surface structure 210, 210' on the cavity wall 250 may make it more difficult to design the sonotrode 25. On the other hand, the anvil 21 ′ does not transmit mechanical vibrations and can be designed more freely and even modified with respect to existing sonotrodes without affecting the vibration mode of the sonotrode.

[0127] Go to FIG. 5A to FIG. 5GIn the example of FIG. 1 , the ultrasonic welding electrode 25 extends between a first end face 253′ and a second end face 253″. The first end face 253′ includes an inlet opening 250′ leading to the 3D cavity 25′, which extends from the first end face 253′ toward the second end face 253″ in the depth direction DD. Therefore, the depth direction DD is aligned with the axial centerline CS2 of the ultrasonic welding electrode 25, and the end faces 253′, 253″ are separated by a distance D3 ( Figure 5D The second end surface 253" is configured to be attached to the conversion unit ( Figure 3 27B in the figure). In the example shown, the second end face 253" is flat and is configured to be bolted to the conversion unit by using a threaded mounting hole 255, which extends axially towards the cavity 25'. It can be understood that the ultrasonic welding electrode 25 is configured to receive mechanical vibrations via the second end face 253".

[0128] The circumferential outer surface 251 extends between the end faces 253', 253". In the example shown, the shape of the outer surface 251 is generally convex in the axial direction. Therefore, near the end faces 253', 253", the distance between the outer surface 251 and the axial centerline is the smallest. The shape of the outer surface 251 is determined by the need for solid material around the cavity 25' in order to achieve a suitable vibration mode of the sonotrode 25 to achieve the desired permanent deformation of the front sleeve portion 11', as described below with reference to Fig. 7A and Figure 7B discussed.

[0129] The cavity 25' is arranged at the center of the first end surface 253'. Thus, the axial center line CS2' of the cavity 25' coincides with the axial center line CS2 of the ultrasonic welding electrode 25 ( Figure 5E , Figure 5G As described above, the cavity 25' is defined by the peripheral cavity wall 250 and the bottom wall 250b, wherein the peripheral cavity wall 250b extends from the entry opening 253' to the bottom wall 250b in the depth direction DD. Depending on the function, the cavity wall 250 can be subdivided into different circumferential wall portions, such as Figure 5E and Figure 5G As shown. The entrance wall portion EW ("entrance wall") is arranged to extend from the entrance opening 250' to an axial distance W1 in the cavity 25' in the depth direction DD. The entrance wall EW is shaped to receive and guide the front sleeve portion 11' into the cavity 25'. In the illustrated example, the entrance wall EW defines a tapered surface. The tapered surface is inclined into the cavity 25' toward the center line CS2' of the cavity 25'. The cavity wall 250 also includes a wall portion SW ("shoulder wall") defining a shoulder, which is configured to shape the shoulder SP of the packaging body 13 by deformation of the front sleeve portion 11' (see Figure 2E). As shown in the figure, the shoulder wall SW can be adjacent to the entrance wall EW, or there can be an intermediate wall portion between the entrance wall EW and the shoulder wall SW. The shoulder wall SW has a range W2 in the depth direction DD. The shoulder wall SW is a part of the band-shaped contact surface 250a. The cavity wall 250 also includes a wall portion NW ("neck wall") defining a neck, which is configured to drive the front sleeve portion 11' to engage with the flange 14' on the neck element 14 when the front sleeve portion 11' on the anvil 21' is pressed into the cavity 25'. The neck wall NW is adjacent to the shoulder wall SW and spans a distance W3 in the depth direction DD. It can be recognized that the neck wall NW is also a part of the band-shaped contact surface 250a. In the illustrated example, the neck wall NW defines a tapered surface that is inclined toward the center line CS2' of the cavity 25'. The cavity wall 250 also includes a bottom wall portion BW ("circumferential bottom wall") which is adjacent to the neck wall NW and is configured to receive the tubular portion 14" of the neck element 14 when the anvil 21' is inserted into the cavity 25'. Figure 5E and Figure 5G In the example of , the circumferential bottom wall BW has an extent W4 in the depth direction DD. When the anvil 21' is inserted into the cavity 25', the circumferential bottom wall BW can be spaced apart from the tubular portion 14" of the neck element 14. This prevents the tubular portion 14" from being damaged by mechanical vibrations. In addition, the spacing ensures that the neck element 14 will not be stuck in the cavity 25" due to welding. However, in some embodiments, the circumferential bottom wall BW may include a surface portion for contacting the tubular portion 14" to achieve intentional patterning or reshaping thereof. The circumferential bottom wall BW is engaged with the bottom wall 250b of the cavity 25'. The bottom wall BW 250b together defines a bottom cavity portion, which is arranged to accommodate the neck element 14 when the anvil 21' is pressed into the cavity 25'.

[0130] As described above, it is conceivable to attach or form the neck element 14 to the top 13' in a separate step after deformation and welding in the sonotrode 25. In such an embodiment, the neck wall NW and the circumferential bottom wall BW can be omitted from the cavity wall 250, and the shoulder wall SW can be configured to deform at least a portion of the front sleeve portion 11' into the top 13'. It is also conceivable to omit the entry wall EW from the cavity wall 250.

[0131] In the illustrated example, the ultrasonic welding electrode 25 includes a plurality of channels 252 extending from an internal opening 252' at the bottom of the cavity 25' to an external opening 252". The channels 252 are arranged to remove debris or liquid that may accumulate at the bottom of the cavity 25' during operation of the ultrasonic welding electrode 25. For example, deformation of the front sleeve portion 11' may generate debris. In some embodiments, the external opening 252" is connected to a pressure control system (not shown) that is operable to generate suction in the channels 252 to draw debris and / or liquid out of the cavity 25'. Suction can be generated when the anvil 21' is inserted into the cavity 25' and / or when the anvil 21' is spaced apart from the cavity 25'. As shown in FIG. Figure 5E and Figure 5G As shown, the channel 252 can be inclined to extend away from the first end surface 253'. The discharge of debris and / or liquid will thus be at least partially driven by gravity. The pressure control system is optional, but can also be used to create an overpressure in the channel 252 to help remove the top 13' from the cavity 25' after the welding operation. Any number of channels 252 can be provided. As shown, the symmetrical arrangement of the channels 252 relative to the cavity 25' can improve the removal of debris and / or fluid. The internal openings 252' of each channel 252 can be formed in the circumferential bottom wall BW and / or the bottom wall 250b.

[0132] In the illustrated example, the sonotrode 25 includes a plurality of shallow depressions 256 formed in the outer surface 251 and including corresponding blind holes 256' ( Figure 5A ). The recess 256 and the blind hole 256' are irrelevant to the operation of the sonotrode 25. The blind hole 256' is used to mount the sonotrode 25 in a fixture during manufacturing, and the recess 256 is provided to provide space for a tool.

[0133] exist FIG. 5A to FIG. 5G In the example of FIG. 2 , the protrusions 254 of the same solid material are symmetrically distributed around the inlet 250 ′. The protrusions 254 radially protrude from the center line CS2 ′ of the cavity 25 ′ and also have an extent in the depth direction DD along the cavity 25 ′. The amount of material of each protrusion 254 increases monotonically toward the inlet opening 250 ′, for example, as Figure 5A When the cross section of the cavity 25' is non-circular and perpendicular to the depth direction DD, the protrusion 254 is included to achieve controllable vibration of the cavity wall 250 at and near the inlet opening 250'. FIG. 5A to FIG. 5G The cavity 25' in the embodiment has a non-circular cross section, such as Figure 5C Here, the inlet opening 250' has a truncated square shape, generally forming an octagon with relatively parallel sides. The minimum distance D1 and the maximum distance D2 to the center line CS2' of the cavity 25' are given by Figure 5CAfter extensive experimentation, it has been found that in the case of uniform material thickness around the inlet opening 250', the mechanical vibrations applied to the cavity wall 250 at and near the inlet opening 250' will differ depending on the distance from the center line CS2'. Therefore, the protrusions 254 are arranged to add mass at the locations of the maximum radial distance D2 from the center line CS2' to at least change the amplitude of the mechanical vibrations of the cavity wall 250 at and near these locations.

[0134] Figure 6 A cross-sectional view of the sleeve 11 is shown positioned on the arm 21. The front sleeve portion 11' is arranged to surround the anvil 21'. The neck element 14 is releasably attached to the mounting structure 212 by a snap fit between the tubular portion 14" and the mounting structure 212. In the illustrated example, the neck element 14 has an integrated cap (see Figure 2E 14"' in the anvil 21'). A portion of the mounting structure 212 protrudes beyond the front edge of the front sleeve portion 11'. The flange 14' of the neck element 14 is located inside the front sleeve portion 11' through the mounting structure 212. Thus, when the front sleeve portion 111' is deformed due to the engagement between the anvil 21' and the cavity wall 250, the outermost portion of the front sleeve portion 12' contacts the flange 14' (see Figure 2E Attachment part AP in ).

[0135] Figure 6 An example of a deformation unit 28 for preforming the deformation zone 10' on the front sleeve part 11' is also shown in cross-section. The deformation unit 28 shown is configured to be arranged in front of the ultrasonic welding electrode 25, for example, as shown in FIG. Figure 3As shown. To this end, the deformation unit 28 is annular to allow the anvil 21' to extend through the deformation unit 28. The deformation unit 28 includes a base element 280 formed as a hollow shaft ring. The legs 281 extend from the base element 280 to the engagement element 282. Each engagement element 282 is arranged to engage the base material of the front sleeve portion 11' in the corresponding deformation zone 10' at the corresponding abutment surface 282' as the anvil 21' is inserted into the deformation unit 28. In the example shown, the abutment surface 282' is flat and inclined so that as the anvil 21' slides into the deformation unit 28, the front sleeve portion 11' is gradually turned toward the anvil 21'. The engagement element 282 can, for example, cause the base material to bend around one or more crease lines. In some embodiments, the engagement element 282 is arranged to be biased toward the front sleeve portion 11' to ensure a clear engagement force between the engagement element 282 and the front sleeve portion 11' on the anvil 21'. In some embodiments, the legs 281 are configured to bend radially, thereby allowing the engagement element 282 to slide along the anvil 21' and onto the arm 21. This will reduce the risk of damaging the sleeve 11. In some embodiments, the deformation unit 28 is a passive component, wherein the engagement element 282 is arranged to inherently engage and deform the front sleeve portion 11' when the anvil 21' slides into the deformation unit 28. The example in Figure 5 is a passive component. In other embodiments not shown, the deformation unit 28 is alternatively an active component, wherein the engagement element 282 is actively moved by an actuator to engage with the front sleeve portion 11' when the anvil 21' has slid into the deformation unit 28. In one example, the engagement element 282 is configured as a tongue that retracts when the anvil 21' is inserted into the deformation unit 28 and then pushed into engagement with the front sleeve portion 11'.

[0136] It has been found to be beneficial to configure the deformation unit 28 so that the engagement elements 282 engage synchronously with the front sleeve portion 11'. This means that the engagement elements 282, whether by an actuator or passively, engage the front sleeve portion 11' at approximately the same time. This will allow a uniform application of the engagement force, thereby enabling the pre-forming of the front sleeve portion 11' to be well controlled. By arranging the engagement elements 282 in opposing pairs, such that they engage the front sleeve portion 11' from diametrically opposite directions, a further well-controlled pre-forming can be achieved. For the same reason, it may be beneficial to arrange the deformation zones 10' to form opposing pairs on the front sleeve portion 11', for example as Figure 2B shown.

[0137] The ultrasonic welding electrode 25 is designed to achieve a desired vibration mode of the cavity wall 250, both with respect to the local direction of the mechanical vibration and the local amplitude of the mechanical vibration. It may be generally desired that the mechanical vibration causes the cavity wall 250 to move approximately at right angles to its local extent. This means that the cavity wall 250 locally vibrates approximately perpendicularly to the front sleeve portion 11' on the anvil 21' at least in the shoulder wall SW and the neck wall NW ( Figure 5E and Figure 5G ). In this case, "substantially vertical" may mean that the local direction of vibration deviates from 90° by less than β, which is ±5°, ±10° or ±15° depending on the embodiment. Non-vertical vibrations may cause significant local wear of the substrate material, excessive formation of debris and may impair the practicality of the package. It may also be generally desirable that the amplitude of the mechanical vibrations be well defined on the cavity wall 250, at least within the shoulder wall SW and the neck wall NW. Different amplitudes lead to different heating and ultimately different welding performance. In some embodiments, the ultrasonic welding electrode 25 is configured to have a consistent mechanical vibration amplitude within the shoulder wall SW. In this case, "consistent amplitude" may mean that the amplitude deviates by less than 5%, 10% or 15% on the shoulder wall SW. It may also be desirable to ensure that the ultrasonic welding electrode vibrates at a single frequency, similar to a tuning fork, to avoid the presence of parasitic or alternative frequencies that consume power.

[0138] The vibration mode of the sonotrode 25 may be evaluated by simulation using a mathematical model of the sonotrode 25. For example, the mathematical model may be based on finite element analysis (FEA), which is commonly used for vibration analysis.

[0139] Fig. 7A shows the data generated by a proprietary simulation program FIG. 5A to FIG. 5G 1 and 2. The estimated vibration mode of the sonotrode 25 in FIG. The sonotrode 25 is shown in cross section at six successive stages during the vibration cycle, indicated by reference numerals 71-76. As shown, the sonotrode changes its shape significantly during the vibration cycle. Likewise, the shape of the cavity 25' changes significantly both in the axial direction and in the radial direction. The shape of the cavity 25' (and the sonotrode 25) is substantially the same between stages 72 and 76 and between stages 73 and 75. Fig. 7A The ultrasonic welding electrode 25 in the embodiment has been designed to vibrate the cavity wall 250 approximately at right angles to its local extent. Figure 7B It is schematically shown in Fig. 7AThe peripheral line PL of the cavity 25' is drawn at different stages 71-76 in FIG. As shown by the double-ended arrow MV, the peripheral line PL moves locally approximately vertically over the vibration cycle. It should be understood that the vibration mode is mainly related to the portion of the cavity wall 250 that will contact the front sleeve portion 11' on the anvil 21' (i.e., the above-mentioned contact surface 250a). In other parts of the cavity 25', the amplitude of the vibration mode can be controlled to prevent accidental contact with the front sleeve portion 11' or the neck element 14.

[0140] The applicants have identified a number of design features of the sonotrode 25 that can be tailored to achieve the appropriate vibration mode.

[0141] The first design feature is the axial extent of the sonotrode 25. The axial extent is the distance D3 between the end faces 253', 253", as shown in FIG. Figure 5D As shown. It has been found that the distance D3 can be matched to the frequency of the power supply signal provided from the power supply unit 27A to the conversion unit 27B, and thus to the expected frequency of the mechanical vibrations in the sonotrode 25. This will reduce the risk of vibrations at parasitic frequencies other than the expected frequency, thereby improving the efficiency and durability of the sonotrode 25. Therefore, for a given sonotrode, the power supply unit 27A is tuned to the sonotrode and is configured to generate a power supply signal with a frequency given by the distance D3 of the sonotrode. Likewise, the conversion unit 27B is adapted to this frequency.

[0142] The second design feature is the shape or contour of the outer surface 251 of the sonotrode 25. It has been found that the shape of the outer surface 251 affects the amplitude and / or direction of the mechanical vibration of the cavity wall 250. The applicant has found that in some embodiments, when the outer surface 251 is shaped to be generally convex in the axial direction of the sonotrode 25, for example FIG. 5A to FIG. 5G As shown, an appropriate vibration mode is achieved. For comparison, it has been found that a cylindrical shape of the outer surface 251 results in an unacceptable vibration mode of the cavity wall 250, at least when the cavity 25' is dome-shaped.

[0143] The third design feature is the radial thickness of the material around the band-like contact surface 250a. It has been found that a suitable vibration mode is obtained when the radial thickness increases in the depth direction DD of the cavity 25' along all or a significant portion of the band-like contact surface 250a. This is Figure 5E and Figure 5G , where the radial thickness is indicated by a thick double-ended arrow. In the example shown, the band-shaped contact surface 250a includes a shoulder wall SW and a neck wall NW. As described above, the neck wall NW can be omitted in some embodiments.

[0144] The fourth design feature is to configure the sonotrode 25 as a solid or unitary block of material. For example, the sonotrode 25 can be manufactured by casting, optionally followed by subtractive machining operations such as grinding, milling, boring, reaming, etc. Alternatively, the sonotrode 25 can be manufactured only by subtractive machining operations. The solid or unitary block of material has no joints or welds, resulting in a clear transmission of mechanical vibrations from the end face 253″ to the cavity wall 250.

[0145] A fifth design feature is the local addition of material around the perimeter of the inlet opening 250', as shown by radial protrusions 254. As discussed above, such local addition of material may facilitate vibration modes when the cavity 25' has a non-circular cross-section transverse to the depth direction DD.

[0146] Figure 8 Shows Figure 3 Alternative configuration for mid-station 2. Figure 8 Station 2 in the production process is shown. Figure 3 In the embodiment, station 2 comprises an indexing device 300, a neck loading device 301, a sleeve loading device 302, a top forming device 303 and an unloading device 304. In addition, station 2 comprises a separate preforming station 303', which is functionally located between the sleeve loading device 302 and the top forming device 303. The indexing device 300 has six elongated holders or arms 21, each of which comprises an anvil 21' at its outer end. The arms 21 are arranged equiangularly on the wheel 22. The indexing device 300 is indexed to six different angular positions I-VI during one full revolution. The devices 301, 302, 303 and 304 can be connected to Figure 3 is identical to the corresponding device in, except that there is no deforming unit 28 in the device 303. In the example shown, the neck loading device 301 is configured to arrange the neck element 14 on the anvil 21' when the anvil 21' moves between positions I and II. Therefore, in position II, the neck element 14' is already attached to the anvil 21'. In an alternative that is not shown, the device 301 can be aligned with position I or II to attach the neck element 14 to the anvil 21'. In position III, the sleeve 11 is slid onto the arm 21 with its front sleeve portion properly aligned with the anvil 21'. In position IV, the pre-forming device 303' is operated to perform a preliminary deformation ("pre-forming") of the front sleeve portion by using the deforming unit 28. The deforming unit 28 can be operated by Figure 6 The deformation unit 28 in is configured in a similar manner. Figure 8In the example of , the deformation unit 28 can be linearly moved between a static position and an operating position, as shown by the double arrow A3'. In the static position, the deformation unit 28 is spaced apart from the anvil 21'. In the operating position, the deformation unit 28 is arranged around the front sleeve portion on the anvil 21'. The pre-forming device 303' includes an actuator or a translation device 26', which is connected to the deformation unit 28 and can be operated to move it between the static position and the operating position. As described above, the deformation unit 28 can be a passive or active component. If it is an active component, the actuator 26' can also be operated to actively engage the deformation unit 28 with the front sleeve portion. In position V, the top forming device 303 is operated to reshape the front sleeve portion into the top of the packaging body 13, while also attaching the neck element 14 to the front sleeve portion. In position VI, the unloading device 304 is operated to remove the packaging body 13 from the arm 21.

[0147] Figure 8 is an example of an embodiment in which the deformation unit 28 is spaced apart from the sonotrode 25 and is operable independently of the sonotrode 25, and the sleeve 11 is moved from the deformation unit 28 to the sonotrode 25 by a conveying device after being preformed by the deformation unit 28. Figure 8 In the example shown, the conveying device is formed by a combination of a wheel 22 and a drive unit 23, but other ways of conveying the sleeve are also conceivable.

[0148] Although the combination of the sonotrode 25 having a 3D cavity 25' and a corresponding 3D anvil 21' has been developed and tested for forming a package top, it can be used to form a sheet material into a three-dimensional surface of any type of product (including non-food packaging), whether or not the sheet material is formed into a sleeve. Therefore, the present disclosure generally provides a sonotrode 25 including a cavity 25', the cavity being defined by a three-dimensional cavity wall 250 and configured to receive a three-dimensional anvil 21', wherein the sonotrode 25 is configured to apply mechanical vibrations to the 3D anvil 21' via the three-dimensional cavity wall 250, and thereby to a sheet material disposed between the three-dimensional anvil 21' and the three-dimensional cavity wall 250.

Claims

1. A device for forming a three-dimensional top (13') of a packaging body (13), characterized in that The device comprises: an anvil (21') having a three-dimensional shape, the anvil (21') being configured to receive a sleeve (11) of a base material (1) such that a front sleeve portion (11') of the sleeve (11) is positioned around at least a portion of the anvil (21'), and A sonotrode (25) defining a three-dimensional cavity (25'), wherein the three-dimensional cavity (25') is configured to receive the anvil (21') and the front sleeve portion (11') on the anvil (21'), and the sonotrode is configured to apply mechanical vibration to the front sleeve portion (11') on the anvil (21') via the three-dimensional cavity (25') to cause permanent deformation of the front sleeve portion (11') to form the three-dimensional top (13').

2. The device according to claim 1, wherein when the front sleeve portion (11') is received in the three-dimensional cavity (25'), the longitudinal center axis (CS2') within the three-dimensional cavity (25') is aligned with the longitudinal center axis (CS1) of the anvil (21').

3. The device according to claim 1 or 2, configured to press the anvil (21') and the sonotrode (25) towards each other with a predetermined force (F) during the application of the mechanical vibrations, so as to compress the base material (1) of the front sleeve part (11').

4. The apparatus according to claim 1 or 2, wherein the three-dimensional cavity (25') extends from an inlet opening (250') into the sonotrode (25) in a depth direction (DD) and is defined by a cavity wall (250) surrounding the three-dimensional cavity (25') in a peripheral direction.

5. The device according to claim 4, wherein the anvil includes a three-dimensional surface portion (211), the shape of the three-dimensional surface portion (211) is consistent with the three-dimensional wall portion (250a) of the cavity wall (250), and the three-dimensional wall portion (250a) is circumferential in the peripheral direction and defines a band-shaped contact surface for engaging with the three-dimensional surface portion (211) of the anvil (21') via the front sleeve portion (11').

6. An apparatus according to any one of claims 4 to 5, wherein at least one of the anvil (21') or the cavity wall (250) includes a surface structure (210), which is configured to cause a local change in the engagement force from the anvil (21') and the cavity wall (250) to the front sleeve portion (11').

7. Apparatus according to claim 6, wherein at least a subset of deformation zones (10') are configured to form a plurality of overlapping layers of the base material (1) when the front sleeve portion (11') is received in the three-dimensional cavity (25').

8. The device according to claim 7, wherein the surface structure (210) comprises elongated recesses configured to receive the plurality of overlapping layers of corresponding deformation zones (10') of the at least one subset of deformation zones.

9. An apparatus according to any one of claims 4 to 8, wherein the cavity wall (250) comprises a wall portion (SW) defining a shoulder, the wall portion being configured to deform at least a portion of the front sleeve portion (11') into a shoulder (SP) of the packaging body (13).

10. An apparatus according to any one of claims 4 to 9, wherein the front end portion of the anvil (21') includes a mounting structure (212) for a neck element (14), the neck element (14) including a tubular portion (14") for defining an entry opening on the packaging body (13), wherein the mounting structure (212) is arranged so that the neck element (14) is at least partially located within the front sleeve portion (11') when the front sleeve portion (11') is located on the anvil (21').

11. The apparatus according to any one of claims 4 to 10, wherein the sonotrode (25) comprises a first end face (253') and a second end face (253"), and a circumferential outer surface (251) extending between the first end face (253') and the second end face (253"), wherein the three-dimensional cavity (25') is formed in the first end face (253').

12. The device according to claim 1 or 2 further comprises a deformation unit (28), which is configured to engage the front sleeve portion (11') on the anvil (21') before the front sleeve portion (11') is received in the three-dimensional cavity (25') to cause preparatory deformation of the front sleeve portion (11').

13. The apparatus according to claim 1 or 2, wherein the base material (1) of the front sleeve part (11') comprises a plastic material (1B), the plastic material (1B) being configured to be softened by the mechanical vibrations applied by the ultrasonic welding electrode (25) and subsequently hardened in the absence of the mechanical vibrations to achieve the permanent deformation of the front sleeve part (11').

14. Apparatus according to claim 1 or 2, wherein said anvil (21') is detachably comprised in an elongated holder (21) for receiving said sleeve (11) of substrate material.

15. A sonotrode comprising a cavity (25'), characterized in that The cavity (25') is defined by a three-dimensional cavity wall (250) and is configured to receive a three-dimensional anvil (21'), and the sonotrode (25) is configured to apply mechanical vibrations to the three-dimensional anvil (21') via the three-dimensional cavity wall (250).

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