Flexible tool and method for integrally bonding two joining partners

Abstract

The invention relates to a tool (1) for integrally bonding a first joining partner (3) to a second joining partner (2). The tool (1) has: a profiled part (4) with a profiled part surface (5) which is in contact with the second joining partner (2) during a joining operation, at least one heating element (6), and at least one elastic element (7). The heating element (6) is situated between the profiled part surface (5) and the elastic element (7). The invention further relates to an integral bonding method and to a system (100) for producing packaging (111) using such a tool (1).

Description

[0001] Flexible tool and method for material-bonded joining of two joining partners

[0002] The invention relates to a tool and a method for joining a first joining partner with a second joining partner by means of a material bond, as well as a system for producing packaging with such a tool.

[0003] The sealing of packaging by means of thermal sealing or welding is known from the prior art, for example by thermal plasticizing a plastic or another thermally reactivated material for joining with another or the same material.

[0004] The object to be sealed or welded, acting as the first joining partner (e.g., a cup, glass container, jar, or bag), may have an uneven joining surface, such as an uneven cup rim or an uneven glass surface on a jar. Furthermore, the thickness of the second joining partner, for example, the seal (e.g., a film with a typical thickness ranging from a few hundredths to tenths of a millimeter), may also vary. These differences in height or thickness can range from a few hundredths of a millimeter to tenths of a millimeter, or even several millimeters. Additional unevenness can result from uneven contact surfaces or mechanical interfaces. For instance, the cell board of a fill-and-close or fill-and-seal (FS) cup machine may be bent or damaged, or the mandrel on which the sealing head is attached may be bent or misaligned.

[0005] For sealing or welding, heated sealing or welding tools, also known as sealing or welding devices, are typically used. These usually have a rigid and flat profile or a profile with a contour, also called a bead, which transfers the heat and pressure necessary for sealing or welding. However, the irregularities described above lead to incomplete contact between the tool and the parts being joined, resulting in insufficient heat and pressure application and ultimately a defective seal or weld.

[0006] To improve contact between the profile and the joining partners, various solutions are known from the prior art. A technically simple solution is the use of elastic materials, such as silicones or elastomers, as a profile, e.g., a sealing contour. Disadvantages of this solution include limited heat transfer due to the low thermal conductivity of the elastic material and a limited service life due to high wear of the elastic material. This leads to regular downtime of the sealing or welding tool for replacing the elastic material. DE 6602588 U describes a device for welding or sealing a lid onto a container made of thermoplastic material at an outwardly projecting container edge.The device consists of a container holder with ring-shaped or frame-shaped welding supports that engage under the container rim, and a heated welding or sealing die that engages the lid rim from above. The welding or sealing die contains a ring of closely spaced pins, which are embedded at one end in a block of flexible material and have welding or sealing support surfaces at their free end that engage under the container rim and lie in a common plane. Under the pressure exerted on them by the welding or sealing die, the welding or sealing support surfaces can move relative to each other, thereby precisely adapting to the shape of the container rim and the lid. However, this solution requires that the object to be sealed has a suitable container rim and is therefore of limited use.

[0007] In another solution option, described in EP 0 203 032 A1, the sealing profile is formed by a metal disc with a multitude of slots extending essentially radially from the periphery to the center. This creates lamellae that result in flexibility and elastic springiness of the sealing profile. A recess filled with metal balls, chips, or granules can be arranged in the area above the lamellae, allowing the lamellae to deflect and also enabling thermal coupling with a heating element located in the base body or the recess.Since this solution uses a single heating element positioned centrally behind the elastic lamellae—that is, on the surface of the lamellae opposite the seal—the sealing profile can only be heated indirectly via the heated base plate. This impairs heat transfer between the heating element and the lamellae, and consequently to the seal and the object being sealed. As a result, dynamic and precise control of the tool temperature at or near the point of contact cannot be guaranteed. This leads to highly fluctuating and uncontrolled temperature deviations at the sealing profile, which in turn result in inconsistent sealing performance and quality variations at the seal seam.

[0008] Against this background, the object of the invention is to provide a tool for material-bonding joining, in particular for sealing or welding, with which the aforementioned disadvantages are overcome as far as possible. A tool for material-bonding joining that enables reliable joining of the joining partners even on non-parallel, e.g., undesirably uneven, surfaces would be desirable. Furthermore, precise control or regulation of the tool temperature at or near the point of action should preferably be ensured. This object is achieved by the subject matter of the independent claims. The dependent claims relate to embodiments.

[0009] The terms used below are defined as follows:

[0010] The term "sealing" refers to the process of creating a material bond between a first component, hereinafter also referred to as the "object to be sealed," and a second component, hereinafter also referred to as the "seal," to close an opening in the first component, for example. This material bond is achieved by melting and bonding a specifically designed sealing layer of a typically multi-layered packaging material as the second component, such as an aluminum lid or cap applied to a glass jar as the first component. The object to be sealed can also be a film, so that, for example, two films are sealed together. In this case, the heat applied during sealing melts only the inner layer of the sealing film, which is responsible for the sealing action and bonds with the film that forms the first component.

[0011] The term "welding" also refers to a material-bonded joining of two components, but unlike sealing, the bond is achieved by melting the base material of both components, which is usually a single material. For example, a polypropylene lid can be welded onto a PP (polypropylene) cup.

[0012] Sealing and welding are used particularly, but not exclusively, in the production of packaging made from thermoplastic materials, such as plastic films or film composites, e.g., plastic films coated with metallic and non-metallic materials, metal foils coated with thermoplastic plastic such as aluminum foil, for example in the production of tubular bags, the closing of containers, for example by sealing plastic film with or without aluminum coating, plastic-coated aluminum foil or other thermally weldable materials onto containers made of plastic with or without coating or of aluminum with plastic coating, or the sealing or welding of films or film composites of the above-mentioned type.

[0013] Sealing or welding three-dimensionally shaped structures is also possible. An example of this is the so-called spout bag, i.e., bags of various types equipped with a screw-on resealing mechanism. The "spout" (from the English word for spout, nozzle, or nozzle) is an injection-molded plastic part that provides a threaded opening which can be opened and closed with a screw cap. The term "first joining partner" refers to an object or product that is to be joined to the second joining partner in the area of ​​the first joining partner's joining surface, e.g., a container, cup, pot, bag, etc. In the context of a sealing process, the first joining partner is the object that is to be joined by the seal. The first joining partner could, for example, be a packaging material.

[0014] The term "second joining partner" refers to an object, such as a film, with which the first joining partner is to be connected during the sealing process, for example, to close an opening in the first joining partner. In the context of a sealing process, the second joining partner is the seal itself, with which the object to be sealed is to be attached. The second joining partner can also be a packaging material.

[0015] The term "tool" refers to a tool used to perform a joining process between two components. A sealing tool is a tool used to perform a sealing process or to seal. A welding tool is a tool used to perform a welding process or to weld.

[0016] The term "profile" refers to the component of the tool used to press the second joining partner onto the joining surface of the first joining partner, and whose profile surface is in contact with the second joining partner during the joining process. The profile is heatable, so that a material-bonded connection between the two joining partners is achieved through the application of pressure and temperature. The profile can have a flat surface with or without recesses, or a three-dimensionally shaped surface, e.g., curved, arched, grooved, and / or textured. The profile surface can also correspond to the shape of a bead.

[0017] In the context of a sealing process, the term "profile" refers to the sealing profile, i.e., the component of the sealing tool with which the seal is pressed onto the sealing surface of the object to be sealed and which, with its sealing profile surface, is in contact with the seal during the sealing process.

[0018] The term "profile segment" refers to a single, definable area of ​​the profile that forms part of the profile surface. All profile segments are mechanically separated from one another, e.g., spaced apart by gaps, and together form the profile. The surface of a profile segment that is in contact with the second joining partner during the joining process is called the profile segment surface.

[0019] In the context of a sealing process, the term "profile segment" refers to a sealing profile segment, i.e., a single, definable area of ​​the sealing profile that forms part of the sealing profile surface. The surface of a sealing profile segment that is in contact with the seal during sealing is called the sealing profile segment surface.

[0020] In this context, a "film" is understood to be a sheet-like structure, preferably a homogeneous one, whose thickness is very small compared to its lateral dimensions. The thickness can, for example, be in the pm or mm range. For instance, the thickness can be between 50 pm and 1000 pm. Consequently, a film has two opposite sides, the distance between which is determined by the film's thickness. These opposite sides can be referred to, for example, as the top and bottom or front and back. The film can preferably be made of a thermoplastic material.

[0021] The products may consist of plastic and optionally other materials, such as metals, fibers, or non-thermoplastic materials. Preferred thermoplastic materials include polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), polyamide (PA), polyetheretherketone (PEEK), and polylactic acid (PLA), whereby the aforementioned materials may also be used as blends or copolymers, as well as in the form of coextruded or laminated structures.

[0022] The term "elastic element" refers to a component whose expansion, e.g., length, changes reversibly in at least one spatial direction under pressure or load, even at a constant temperature. The extent of this change in length is called the spring deflection. The elastic element can also be called a spring. It can be designed, for example, as a helical spring or a rubber spring, e.g., in the form of a solid elastomer block.

[0023] The term "elastomer" refers to a dimensionally stable but elastically deformable plastic whose glass transition temperature is below its service temperature and is, for example, less than 20 °C, less than 10 °C, or less than 0 °C. Typical examples of elastomers are styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butadiene rubber, ethylene propylene diene monomer rubber, thermoplastic elastomers, and silicone rubber.

[0024] A first aspect of the invention relates to a tool for joining a first joining partner to a second joining partner by means of a material bond, for example, a sealing tool for applying a seal to an object to be sealed or a welding tool. The tool has a profile with a profiled surface, wherein the profiled surface is in contact with the second joining partner during a joining process. Furthermore, the tool has at least one heating element and at least one elastic element. The heating element is arranged between the profiled surface and the elastic element. For example, the heating element can be integrated into the profile or arranged between the profile and the elastic element.From the perspective of the joining partners, the following arrangement sequence results: profile surface - profile with integrated heating element - heating element, if this is not integrated into the profile - elastic element - optionally a thermally insulating base body - optionally a housing with integrated control electronics.

[0025] The heating element can preferably be small, allowing for very uniform or incremental heating. For example, the heating element can have a length and width in the range of 2 to 20 mm, or 2 to 10 mm, and a thickness in the range of 0.1 to 5 mm.

[0026] The elastic element advantageously allows for flexible adaptation to uneven surfaces, such as uneven joining surfaces and / or joining partners. It can also, for example, adapt to layer changes in (paper) bags, i.e., transitions between, for example, two bag layers and three or four bag layers.

[0027] At the same time, the arrangement of the heating element close to the second joining partner, i.e., viewed from the second joining partner in front of the elastic element, enables heat supply close to the point of action and, if necessary, heat control, so that particularly precise temperature control is possible even under load, i.e., when heat is dissipated by the joining partners, and under different load scenarios.

[0028] Undesirable decreases or fluctuations in surface temperature, which depend on the machine's operating state and behavior, can be avoided by arranging the heating elements and, if necessary, sensors close to the point of contact, in conjunction with rapid control of the heating elements. Furthermore, this close-contact arrangement ensures that the surface temperature remains virtually identical from one joining cycle to the next, as the heat dissipated by the joining partners can be directly replenished.

[0029] Exemplary load scenarios include start-stop scenarios where the machine runs for a short time, dissipating heat, and then stops again, during which no heat is dissipated. Providing heat close to the point of application can prevent the temperature from overshooting or, when the machine restarts, from dropping below the setpoint. The short control path, achieved by positioning the heating element close to the second joining partner, reduces otherwise occurring delays.

[0030] Due to the proposed arrangement, heating the elastic element for joining is unnecessary, thus preventing heat losses. Since the heat flow in the proposed arrangement is not obstructed by the elastic element, heat input can be significantly more efficient. Overall, more uniform joining processes, such as sealing or welding, are possible, and a higher joining quality can be achieved.

[0031] Depending on the design variant, the profile can have several profile segments.

[0032] The profile segments can be designed, for example, as a prism (e.g., with a base and top surface formed as a circular or annular segment), as a cube, or as a cuboid. The specific geometric design of the profile segments, their arrangement, and number can depend on the geometric design of the desired profile surface. For example, a round profile surface can be formed by eight, twelve, sixteen, or more segments, depending on the diameter of the profile surface. In a linear arrangement of the profile segments, there can be up to several hundred profile segments, e.g., up to three hundred.

[0033] A profile segment can contain one or more heating elements.

[0034] The spacing between the profile segments can be a few hundredths or tenths of a millimeter, e.g., 0.01 mm to 0.4 mm. This allows for the most consistent possible application of heat and pressure during joining, thus ensuring high-quality joining.

[0035] The dimensions of the profile segments can range from a few millimeters. The surface area of ​​a profile segment, for example, can be approximately 4 mm². 2 up to 400 mm 2 The dimensions of the profile segments can preferably be adapted to the joining application in such a way that typical height profiles can be compensated for and mechanical and thermal contact with the second joining partner, e.g. lid on container or film on films with different film thicknesses, is always ensured.

[0036] Each profile segment, or multiple profile segments, can be assigned an elastic element. The more elastic elements are provided, the more precisely the adaptation to unevenness can be achieved. Alternatively, all profile segments can share an elastic element. This can improve the mechanical stability of the tool, resulting, for example, in a more uniform pressure distribution during joining.

[0037] According to further design variants, each profile segment can be assigned at least one heating element for heating that profile segment. Optionally, several heating elements can be assigned to each or some profile segments. "Assigned" here means that the surface of the profile segment can be heated by means of the assigned heating element. The heating elements can be configured as described above.

[0038] By assigning at least one heating element to each profile segment, the heating element can adapt to uneven surfaces and direct contact with the surface of the second joining partner is possible. This enables heat supply and control that is particularly close to the point of action, allowing for highly precise temperature control.

[0039] Optionally, the heating elements can be individually or group-wise controlled or regulated. This allows a thermal profile to be created, so that, for example, certain areas of the joining surface can be subjected to a higher temperature than others, as required. This can contribute to increased joining quality and / or improved functionality of the resulting joint, such as locally varying opening behavior, e.g., easier opening or peeling.

[0040] According to further embodiments, the elastic element can comprise or consist of an elastomer. Preferably, the elastomer can be selected from the group comprising silicone rubber and perfluorocarbon rubber.

[0041] Elastomers can be manufactured cost-effectively and in a wide variety of geometric shapes. Furthermore, their elastic properties, such as spring deflection, can be flexibly and precisely adjusted by selecting appropriate manufacturing parameters. Elastomers are also characterized by high corrosion resistance.

[0042] It can also be designed so that the elastic element exhibits different elastic behavior in certain areas, i.e., certain areas are more elastic than others. For example, in the case of a layer transition with thick paper, the area of ​​the layer transition can be designed to be more compliant than the rest of the profile, e.g., the sealing strip.

[0043] Alternatively or additionally, the elastic element can have a metallic material or be made of a metallic material. This can achieve improved resistance to aggressive chemicals.

[0044] The metal material can be, for example, (stainless) steel or a copper alloy. The use of different metal materials is also possible.

[0045] The maximum travel of the elastic element can be, for example, 5 mm, 2 mm, or 0.5 mm. Limiting the maximum travel ensures that the pressure required for sealing is applied evenly, despite unevenness. In other words, the maximum travel should be as large as necessary to compensate for the unevenness, but also as small as possible to avoid negatively impacting the pressure application.

[0046] According to further design variants, the elastic element can be replaceable.

[0047] This allows for the replacement of the elastic element(s), e.g. in case of wear or to use an elastic element with a different elasticity behavior.

[0048] Each profile segment can be assigned at least one elastic element. Optionally, each or some profile segments can be assigned multiple elastic elements, or several profile segments can share a common elastic element.

[0049] Depending on the design, a single elastic element can be present in the form of a solid elastomer block. This allows for particularly good adaptation to uneven surfaces while simultaneously ensuring uniform pressure for joining.

[0050] According to further embodiment variants, the profile or profile segments can be movable in three degrees of freedom, preferably in four degrees of freedom, and particularly preferably in five degrees of freedom.

[0051] For example, the profile segments around the fixing point of a connecting element can be freely movable, with the movement limited only by the adjacent profile segments. This allows for very flexible adaptation to uneven surfaces.

[0052] According to further design variants, the profile segments can be arranged radially, linearly or along a contour.

[0053] In other words, the profile segments can be evenly distributed around a common center point or arranged in one or more rows, e.g., in the form of a sealing strip. Alternatively, the profile segments can be arranged along a contour, e.g., a rectangular, oval, or other contour, which may, for example, correspond to the shape of an opening in the first joining partner.

[0054] The profile segments can be arranged in a single plane to form a flat profile surface. Alternatively, they can be arranged to create a three-dimensionally shaped profile surface.

[0055] A radial arrangement can result in improved joining, especially with circular or annular joining surfaces, while a linear arrangement is preferred for angular, e.g. rectangular, joining surfaces.

[0056] According to further design variants, the profile segments can be arranged in such a way that a three-dimensionally shaped profile surface is formed.

[0057] Such a three-dimensionally shaped profile surface opens up further sealing and welding application areas, e.g. the joining of spouts or pourers.

[0058] According to further design variants, the profile or profile segments can be held by connecting elements, e.g. in a radial arrangement.

[0059] The connecting elements can be made of an elastic material, such as spring steel. This allows for further movement of the profile or profile segment and thus further improved adaptation to uneven surfaces.

[0060] According to further design variants, the heating element can be embedded in the profile segment.

[0061] If multiple heating elements are present, then of course several or all of the heating elements can be embedded in the profile segment. Preferably, the heating element(s) assigned to the profile segment can be embedded in the profile segment.

[0062] Embedding can include a material-bonded connection, which can be achieved, for example, by welding or gluing. Embedding the heating element provides a high level of protection, e.g., against mechanical damage, corrosion, or damage caused by moisture.

[0063] According to further design variants, the heating element can have a ceramic or polymer substrate or plastic substrate with resistance-based heating conductors.

[0064] The heating conductors can be embedded or integrated into the substrate, or applied to the substrate, e.g., printed. The heating conductors can be made of a metallic material and be designed as metallic resistance heating conductors.

[0065] For example, a heating element can comprise a flat substrate with a front and a back, on the front of which at least one heating circuit is arranged. In this context, "flat" means, for example, "in the form of a plate," which can be flat, curved, or convex. In the simplest case, a substrate contains exactly one heating circuit. Alternatively, two or more heating circuits can be arranged on the substrate. The heating element can be manufactured, for example, using a thin-film coating process from metal or a thick-film printing process from conductive paste or conductive ceramic slurry, i.e., by layering ceramic conductor circuits. Alternatively, the heating element can be designed as a ceramic volume heater, i.e., milled from a conductive ceramic material.

[0066] It can be advantageous to provide that the heating elements can be individually controlled. It can be particularly advantageous that each individual heating circuit can be controlled separately from all other heating circuits, even those located on the same substrate, with regard to its heating power or target temperature. For this purpose, the heating elements can be connected to a control unit via a signal connection, which can also be part of the proposed tool.

[0067] According to further design variants, the heating element or elements can be designed for temperature measurement.

[0068] In other words, the individual heating elements can have an integrated temperature measurement function. For temperature measurement, the temperature-dependent resistance behavior of a resistive heating circuit within the heating element itself can be used, for example, and / or the temperature measurement can be achieved using an additionally applied, e.g.,...

[0069] B. printed, sensor, whereby the sensor can be designed, for example, as a resistance sensor or thermocouple.

[0070] The temperature measurement can be used to control the heating circuit(s) of the heating elements by transmitting the temperature readings to a control unit. The control unit processes the temperature readings based on instructions or code programmed into the control unit, according to one or more routines, and sends control signals to the heating circuits.

[0071] It is also possible to design the device so that only some, but not all, of the heating elements are equipped for temperature measurement. Similarly, in the case of multiple heating circuits per heating element, it may be possible to design the device so that only some, but not all, of these heating circuits are used for temperature measurement. For example, a single temperature measurement can be used to control two heating circuits. The more temperature measurement points there are, the more accurately the temperature can be determined and the more precisely the heating circuits can be controlled. However, with an increasing number of temperature measurement points, the complexity of the temperature measurement and the control systems based on it also increases. According to further design variations, the device can have a thermally insulating base.

[0072] One function of the thermally insulating base body is to thermally insulate the heated profile from the control electronics and mounting hardware located behind it (viewed from the profile surface). This insulating base body is also responsible for transmitting the required joining force and is therefore designed to be correspondingly robust. This base body can thus simultaneously serve as a support structure.

[0073] The base body can, for example, be made of a high-temperature-resistant plastic such as PEEK or glass fiber reinforced plastics or silicone resin composites, but also ceramics or comparable inorganic materials, as well as metals with poor thermal conductivity, e.g., stainless steel, or consist of one of the aforementioned materials or combinations thereof. Preferably, the base body can be made of a material whose thermal conductivity is in the range of 0.1 W / (m K) to 15 W / (m K), preferably in the range of 0.1 W / (m K) to 10 W / (m K).

[0074] According to further design variants, the profile can have or consist of a material with a thermal conductivity of more than 10 W / (m K). If the profile comprises several profile segments, then the profile segments accordingly have a material with a thermal conductivity of more than 10 W / (m K).

[0075] In other words, the material of the profile or profile segments can have high thermal conductivity and is preferably made of a metal such as aluminum, copper, an aluminum alloy or a copper alloy.

[0076] According to further design variants, the profile or profile segments can be made of or consist of stainless steel. Preferably, a stainless steel with a thermal conductivity of more than 10 W / (m K) can be used.

[0077] The use of stainless steel can advantageously contribute to increased resistance to cleaning agents or highly reactive environments, such as those encountered during sterilization with hydrogen peroxide, as well as improved corrosion resistance.

[0078] According to further design variations, the profile can contain an elastomer or be made of an elastomer. For example, the elastomer can be selected from a group including silicone rubber and perfluorocarbon rubber.

[0079] This further enhances the ability to adapt to uneven surfaces. Furthermore, surface damage caused by the tool impacting the first and second joining partners can be largely avoided. Potential negative effects of reduced thermal conductivity are minimized by the thin profile and the small distance between the profile surface and the heating element.

[0080] According to further design variants, the tool can have a vacuum connection to create a negative pressure in the area of ​​a recess, for example a circular recess, of the profile.

[0081] The recess can, for example, be closed by means of a cover that has channels through which a vacuum can be applied via the vacuum connection. The vacuum can then be used to hold the second joining partner against the profile surface.

[0082] Due to the proposed heating of the profile surface near the point of action by arranging the heating element(s) in the area of ​​the profile surface and the surrounding heat-insulating materials, the area of ​​the recess or the cover only heats up slightly, so that applying the negative pressure is possible without problems.

[0083] Another aspect of the invention relates to a method for joining a first joining partner to a second joining partner by means of a material bond, wherein a tool according to the above description is used.

[0084] The process can be, for example, a sealing or welding process; for example, a three-dimensionally shaped contour, e.g., a spout, can be sealed or welded.

[0085] As already mentioned, a tool with a three-dimensionally shaped profile surface can be used for this purpose. Particularly good adaptation to the three-dimensional contour can be achieved through the elastic elements of the tool.

[0086] Alternatively or additionally, a layer jump, i.e. a transition from a first number of material layers to a second number of material layers, can be sealed or welded, whereby the first number differs from the second number.

[0087] For example, a layer break in flexible packaging made of plastic or paper composite can be sealed. Thanks to its elastic elements, the proposed tool allows for flexible adaptation to varying numbers of layers, ensuring a secure seal and preventing leaks at the seal or weld seam.

[0088] Another aspect of the invention relates to a plant for the production of packaging. In particular, packaging with a plastic film, such as plastic packaging, but also cardboard or paper packaging with a plastic film, e.g. as a laminate, can be produced.

[0089] The proposed system incorporates a tool as described above. Therefore, the above explanations of the tool also serve to describe the system. The advantages of the tool and its various designs are inherently linked to the system.

[0090] The system can be, for example, a fill-and-close or fill-and-seal system, where a container, such as a cup or jar, is filled and then sealed, or a form-fill-and-close system, where the container is also formed first. The forming process can be thermoforming, meaning the packaging system can also be a thermoforming system.

[0091] Alternatively, the packaging system can be a system for flexible packaging materials (plastic or paper composite), e.g. a VFFS system, vertical form fill sealing machine, or an HFFS system, horizontal form fill sealing machine.

[0092] Alternatively, the plant could be a bag manufacturing plant or a plant for the production of packaging with spouts.

[0093] Alternatively, the system can be a system for sealing laminated cardboard or paper packaging, e.g. cups or trays, which can also be integrated into an inline laminating system.

[0094] In addition to the tool described above, the system may include further tools, devices and equipment, such as a device for heating a film that can be used as a seal and a transport device for transporting the film from a film reservoir, e.g. a film roll, to various processing stations, such as a forming tool, designed and equipped for forming the heated film, the forming tool comprising, for example, a forming bowl and a forming tool lid.

[0095] In summary, various aspects of the invention can be described as follows: One proposed solution involves segmenting the profile of a joining tool, with the profile segments being directly equipped with controlled heat sources. The individual heat sources, e.g., heating circuits or heating pixels, based on small heating elements (e.g., ceramic elements) with integrated temperature measurement, are arranged in segments and are additionally mounted individually and elastically to allow for flexible adaptation to uneven joining surfaces, joining partners, and / or deviations in the mechanical contact elements or interfaces. The size of the segments, e.g.,Measuring a few millimeters in width and length, the elastic elements are adapted to the application in such a way that typical height profiles can be compensated for, ensuring consistent mechanical and thermal contact with the sealing material or the lid on containers or films of varying thicknesses. The elastic elements are thus positioned not in front of, i.e., between, the joining partners and the heat source, but behind it. The incrementally designed heating element also adapts to the contour of the joining surface, thereby establishing a direct connection with the surface of the second joining partner. This enables heat input and control close to the point of action, allowing for particularly precise temperature control even under load and various load scenarios. The elastic elements can also be made of elastomers or springs, or resilient elements, which, as wear parts, are also replaceable.

[0096] The invention is explained below by way of example with reference to the accompanying figures and preferred embodiments, whereby the features shown below can represent an aspect of the invention both individually and in various combinations with one another.

[0097] For clarity, the described examples refer to sealing tools and sealing processes. Analogously, welding tools can be designed and welding processes carried out. Therefore, the explanations regarding sealing tools and sealing processes are also applicable to welding tools and welding processes.

[0098] The figures are not necessarily detailed or to scale and may be enlarged or reduced to provide a better overview. Therefore, the functional details disclosed here are not to be understood as limiting, but merely as an illustrative basis to guide those skilled in this field of technology in using the present invention in a variety of ways.

[0099] The expression "and / or" used here, when used in a series of two or more elements, means that each of the listed elements can be used alone, or any combination of two or more of the listed elements can be used. In the figures, identical or similar elements are marked with identical reference symbols where appropriate.

[0100] Figure 1 shows a first schematic diagram of a first exemplary sealing tool with radially arranged sealing profile elements;

[0101] Fig. 2 shows another schematic diagram of the sealing profile of the sealing tool from Fig. 1;

[0102] Fig. 3a, b shows a detailed view of a seal embedded in a seal profile segment.

[0103] Heating element;

[0104] Fig. 4 shows a schematic diagram of another exemplary sealing tool with radially arranged sealing profile segments;

[0105] Fig. 5 is a schematic diagram of the sealing profile of the sealing tool from Fig. 4;

[0106] Fig. 6 shows a schematic diagram of another exemplary sealing tool seal profile with linearly arranged seal profile segments;

[0107] Fig. 7 is a schematic diagram of the sealing profile of the sealing tool from Fig. 6;

[0108] Fig. 8 shows a schematic diagram of another exemplary sealing tool seal profile with three-dimensionally arranged seal profile segments; and

[0109] Fig. 9 shows a schematic diagram of an exemplary plant for the production of packaging.

[0110] Fig. 1 shows a schematic representation of an exemplary sealing tool 1 with a round sealing head. The sealing tool 1 has a sealing profile 4 with an annular sealing profile surface 5, which is in contact with the seal as the second joining partner 2 during sealing.

[0111] In this embodiment, the sealing profile 4 consists of sixteen sealing profile segments 8, which are designed as circular ring segments, arranged radially to one another around a recess 18 (see Figure 2), and whose sealing profile segment surfaces 9 are in contact with the second joining partner 2 during sealing. The diameter of the sealing profile surface 5 can be, for example, between 20 mm and 200 mm, but can also be smaller or larger, depending on the specific application.

[0112] The sealing profile segments are held in a radial arrangement by means of connecting elements 14, which connect the sealing profile segments 18 to a mounting area 17 (see Figure 2). In the exemplary embodiment, the connecting elements 14 consist of a stainless steel spring sheet, preferably corrosion-resistant, and can yield elastically to the mounting area 17 in order to allow additional elastic deflection of the sealing profile segments 8.

[0113] In the exemplary embodiment, the sealing profile segments 8 are made of aluminum, a material with a thermal conductivity of more than 10 W / (m K). The sealing profile segments 8 are supported by an elastic element 7, which in the first exemplary embodiment is designed as a solid elastomer block in the form of a hollow cylinder. The elastic element 7 allows for a deflection of a few tenths of a millimeter up to a few millimeters; that is, depending on the specific design, the deflection ranges from a few tenths of a millimeter to a few millimeters.

[0114] The gaps between the sealing profile segments 8 are a few tenths of a millimeter to allow continuous heat and pressure application and thus a high-quality seal. The sealing profile segments 8 have five degrees of freedom and are freely movable around the fixing of the connecting element 14 and radially limited only by the adjacent sealing profile segments 8. In other words, movement is only restricted in the direction of the center of the fastening area, but movement in the other two spatial directions as well as torsional movements, i.e., yaw, pitch, and roll, are possible.

[0115] The sealing tool 1 also has a thermally insulating base body 12. This base body 12 thermally insulates the area of ​​the sealing profile 4 from the control electronics and mounting (not shown) located behind it in the housing 13. The base body 12 is also responsible for transmitting the required sealing force and is designed to be correspondingly robust.

[0116] Each of the sixteen sealing profile segments 8 has a heating element 6 integrated or encapsulated within it. The heating elements 6 are embedded in the respective sealing profile segment 8 and bonded together, e.g., welded or glued, to protect them from mechanical or other influences, e.g., moisture, etc. (see Figure 3).

[0117] The heating elements 6 are small, flat bodies, a few millimeters in size, which preferably have a ceramic or polymer substrate 10 with embedded or applied resistance-based heating conductors 11 (see Figure 3). In the exemplary embodiment, each heating element 6 has a single heating conductor 11 or heating circuit. However, several heating conductors 11 can also be present, forming multiple heating circuits that can be controlled independently of one another. The individual heating elements 6 have an integrated temperature measurement function. For this purpose, either the temperature-dependent resistance behavior of the resistive heating circuit itself can be used, or a separate sensor is provided, e.g., as a resistance sensor or thermocouple.

[0118] The electrical contact, i.e., the connection of the heating circuits and, if applicable, sensor circuits to the control electronics, is effected by means of cables, in particular flat cables, which are led out of the sealing profile segment 8 and are designed in such a way as to enable the desired movements of the elastically mounted sealing profile segment 8. The control or regulation of the heating elements 6 can be effected by means of a control unit 15, which, for example, can be arranged as control electronics in the housing 13 or alternatively can be implemented by a control unit 15 of a thermoforming machine 100 (see Figure 5).

[0119] As shown in Figure 1, the recess 18 of the sealing tool 1, i.e., the area of ​​the connecting elements 14 and the fastening area 17, can be closed with a cover 19. The cover 19 is made of a thermally insulating material to largely prevent heating in the area of ​​the recess 18. Small channels 20 can be integrated into the cover 19, through which, for example, a vacuum can be applied, e.g., to hold the cover 19 in the desired position.

[0120] The sealing tool 1 also has a coolant connection 21, through which a coolant can be supplied to the housing 13 to cool the electronic components arranged in the housing 13. Furthermore, the sealing tool 1 has a vacuum connection 22, which is operatively connected to the channels 20. In other words, a vacuum can be applied to the channels 20 via the vacuum connection 22, so that, for example, a seal 2, e.g., a lid, can be held in place by vacuum.

[0121] Figure 3a shows a detailed view of an exemplary heating element 6 with a ceramic thick-film substrate 10 and a metallic heating conductor 11, which is printed or deposited onto the substrate 10. The heating element e is embedded in a sealing profile segment 8 and adapted to the geometric shape of this sealing profile segment 8 in the manner of a slice of cake.

[0122] The heating element 6 is designed for temperature measurement by determining the temperature based on the temperature-dependent resistance behavior of the heating conductor 11. The heating element e is in a signal communication with a control unit 15, so that the control unit 15 can receive and process the temperature measurements and output control signals to the heating element 6 based on these measurements.

[0123] Figure 3b shows a detailed representation of another exemplary heating element 6. In contrast to the variant according to Figure 3a, the heating element 6 has a cuboid or cube-shaped form, so that it does not fill the shape of the sealing profile segment 8.

[0124] Figure 4 shows a further embodiment of an exemplary sealing tool 1 with radially arranged sealing profile segments 8 in a side view. In Figure 5, the sealing profile segments 8 of the sealing profile 4 of Figure 4 are shown in a viewing direction perpendicular to the sealing profile surface 5.

[0125] As in the first embodiment described above with reference to Figures 1 to 3, the sealing tool 1 of this embodiment also has a housing 13, a base body 12, elastic elements 7 and sealing profile segments 8 arranged radially around a recess 18, wherein exactly one heating element 6 is integrated into each sealing profile segment 8 (shown in dashed lines in Figures 4 and 5).

[0126] In contrast to the first embodiment, there is not just a single elastic element 7, but rather each sealing profile segment 7 is assigned an elastic element 7 in the form of a helical spring. The elastic element 7 also serves to hold the respective sealing profile segment 8, thus eliminating the need for separate connecting elements 14. However, connecting elements 14 can still be present even with multiple elastic elements 7. For further details, please refer to the description of the first embodiment.

[0127] Figure 6 shows a further embodiment of an exemplary sealing tool 1 with linearly arranged cuboid sealing profile segments 8 in a side view. In Figure 7, the sealing profile segments 8 of the sealing profile 4 of Figure 6 are shown in a viewing direction perpendicular to the sealing profile surface 5. In contrast to the embodiments described with reference to Figures 1 to 5, the sealing profile segments 8 are therefore not arranged radially, but linearly in series to form a sealing strip. As in the second embodiment (Figures 4 and 5), each sealing profile segment 8 can have an elastic element 7, as shown in Figure 6. Alternatively, only a single elastic element 7 can be provided analogously to the first embodiment, e.g., as an elastomer block. For further details, please refer to the explanations of Figures 1 to 5.

[0128] Figure 8 shows a further embodiment of an exemplary sealing tool 1 with three-dimensionally arranged cuboid sealing profile segments 8 in a side view. The view in the direction perpendicular to the sealing profile surface 5 of this embodiment corresponds to Figure 7. In contrast to the embodiment described with reference to Figures 6 and 7, the sealing profile segments 8 are arranged linearly, but also three-dimensionally, in order to allow, for example, the insertion of a spout into a package 111. For this purpose, the spout can be arranged in the centrally shown three-dimensionally curved area of ​​the sealing profile 4. The elastic elements 7 enable a very good adaptation to the shape of the spout, so that a high sealing quality can be achieved. For further details, please refer to the explanations of Figures 1 to 7.

[0129] Figure 9 shows an embodiment of a system 100 for manufacturing a package 111 with a sealing tool 1. The sealing tool 1 can be configured, for example, as described above with reference to Figures 1 to 4. The system 100 has a transport device 103, which can be configured, for example, as at least partially driven transport rollers. By means of the transport device 103, an object to be sealed, as the first joining partner 3, which can be configured, for example, as a shell as shown in Figure 8, but can also have a different shape, can be moved along the transport direction 104 and fed to the sealing tool 1.

[0130] In the sealing tool 1, the first joining partner 3 is sealed with a seal as the second joining partner 2 in the form of a film, which is fed from a film roll 101. After sealing, individual packages can be separated from each other by means of a cutting tool 102, so that the individual packages 111 are released.

[0131] A control unit 15 is provided to control the sealing tool 1, which generates control signals 16 and outputs them to various actuators.

[0132] The control signal 16 is output to the sealing tool 1, which is connected to the control unit 15 via a signal transmission system. The control signal 16 causes the object 3 to be sealed to be sealed with the top film or the seal 2, for example, by selectively welding the top film to the object 3. For example, the sealing tool 1 can move perpendicular to the transport direction 104 and apply the temperature and pressure necessary for sealing to the sealing or welding area, resulting in a material-bonded connection between the first joining partner 3 and the second joining partner 2. The control signal 16 can also, for example, activate or deactivate the heating elements 6 and, if necessary, set different temperatures. For example, the temperature can be somewhat lower in the area of ​​an opening flap, i.e.,They are sealed at a lower temperature to locally reduce the required opening forces and allow for easy opening.

[0133] List of reference signs

[0134] Tool of the second joining partner, first joining partner

[0135] profile

[0136] Profile surface

[0137] Heating element elastic element

[0138] Profile segment

[0139] Profile segment surface

[0140] substrate

[0141] heating conductor

[0142] basic body

[0143] Housing

[0144] Connecting element

[0145] control unit

[0146] Control signal

[0147] Mounting area

[0148] Exclusion

[0149] cover

[0150] channel

[0151] Coolant connection

[0152] Vacuum connection

[0153] Attachment

[0154] Film roll cutting tool transport device transport direction packaging

Claims

Patent claims 1. Tool (1) for joining a first joining partner (3) with a second joining partner (2), the tool (1) comprising: a profile (4) with a profile surface (5) which is in contact with the second joining partner (2) during a joining process, at least one heating element (6), at least one elastic element (7), wherein the heating element (6) is arranged between the profile surface (5) and the elastic element (7).

2. Tool (1) according to claim 1, wherein the profile (4) has several profile segments (8).

3. Tool (1) according to claim 2, wherein at least one heating element (6) is assigned to each profile segment (8) for heating this profile segment (8).

4. Tool (1) according to claim 3, wherein the heating elements (6) are individually or group-wise controllable or adjustable.

5. Tool (1) according to one of the preceding claims, wherein the elastic element (7) comprises an elastomer and / or a metallic material.

6. Tool (1) according to one of the preceding claims, wherein the elastic element (7) has a spring travel of a maximum of 5 mm.

7. Tool (1) according to one of the preceding claims, wherein a single elastic element (7) in the form of a solid elastomer block is present.

8. Tool (1) according to one of the preceding claims, wherein the profile (4) or the profile segments (8) are movable in three degrees of freedom, preferably in four degrees of freedom, particularly preferably in five degrees of freedom.

9. Tool (1) according to any one of claims 2 to 8, wherein the profile segments (8) are arranged radially, linearly or along a contour.

10. Tool (1) according to one of claims 2 to 9, wherein the profile segments (8) are arranged such that a three-dimensionally shaped profile surface (5) is formed.

11. Tool (1) according to one of the preceding claims, wherein the profile (4) or the profile segments (8) are held by connecting elements (14).

12. Tool (1) according to one of claims 2 to 11, wherein the heating element (6) is embedded in the profile segment (8).

13. Tool (1) according to one of the preceding claims, wherein the heating element (6) has a substrate (10) made of a ceramic material or a plastic with resistance-based heating conductors (11).

14. Tool (1) according to one of the preceding claims, wherein the heating element (6) is designed for temperature measurement.

15. Tool (1) according to one of the preceding claims, comprising: a thermally insulating base body (12).

16. Tool (1) according to one of the preceding claims, wherein the profile (4) comprises stainless steel.

17. Tool (1) according to one of the preceding claims, wherein the profile (4) comprises an elastomer.

18. Tool (1) according to one of the preceding claims, comprising: a vacuum connection (22) for forming a vacuum in the area of ​​a recess (18) of the profile (4).

19. Method for joining a first joining partner (3) with a second joining partner (2), wherein the joining is carried out with a tool (1) according to one of claims 1 to 18.

20. Method according to claim 19, wherein the material-bonding joining is sealing or welding.

21. Method according to claim 20, wherein a three-dimensionally shaped contour and / or a layer transition is sealed or welded.

22. Plant (100) for the production of packaging (111) with a tool (1) according to one of claims 1 to 18.

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