Sealing device and method for sealing a component to a workpiece by means of ultrasound

Abstract

What is described and shown is a sealing device (1) for sealing an equipment element (2) to a workpiece (3), particularly a workpiece in the form of a composite laminate, by means of ultrasonic waves. The sealing device has an ultrasonic generator (5) for generating ultrasonic waves, a sealing surface (6) for transmitting ultrasonic waves to the equipment element (2) and / or the workpiece (3), an anvil (7) opposite to the ultrasonic generator (5), and an adjustment device for adjusting the ultrasonic generator (5) and the anvil (7) relative to each other from an open position to a closed position and back, the open position for introducing the equipment element (2) and the workpiece (3) into a sealing gap (4) between the ultrasonic generator (5) and the anvil (7) at least partially, and the closed position for pressing the workpiece (3) and the equipment element (2) at least partially between the sealing surface (6) of the ultrasonic generator (5) and the anvil (7) respectively during ultrasonic sealing. In order to avoid damage and non-sealing of the workpiece or packaging laminate due to ultrasonic sealing of the equipment element, such as the tilter, to the workpiece or packaging laminate in areas such as grooves, at least one pair of mating clamping elements (10, 11) that are vibrationally decoupled relative to the sealing surface (6) are provided on opposite sides of the sealing gap (4) for clamping the workpiece (3) in the closed position, and the at least one pair of clamping elements (10, 11) are provided outside the sealing surface (6) relative to the equipment element (2) and viewed along the direction of the sealing gap (4).

Description

Technical Field

[0001] This invention relates to a sealing device for sealing an accessory element onto a workpiece, particularly a workpiece in the form of a composite laminate, by means of ultrasonic waves. The sealing device comprises: an ultrasonic generator for generating ultrasonic waves; a sealing surface for transmitting ultrasonic waves to the accessory element and / or the workpiece; an anvil opposite the ultrasonic generator; and an adjusting device for adjusting the ultrasonic generator and the anvil relative to each other from an open position to a closed position and back again. The open position is used to at least partially introduce the accessory element and the workpiece into a sealing gap between the ultrasonic generator and the anvil, and the closed position is used to at least partially compress the workpiece and the accessory element between the sealing surface of the ultrasonic generator and the anvil, respectively, during ultrasonic sealing. Furthermore, this invention relates to a method for sealing an accessory element onto a workpiece, particularly a workpiece in the form of a composite laminate, by means of ultrasonic waves. Background Technology

[0002] The workpiece can be constructed in the form of a packaging laminate. Packaging laminates are used to form packaging for containing various products to be filled. These products mostly involve food, especially beverages, which may have block-shaped components as needed. In principle, the products are pourable or flowable, particularly liquid. Packaging for containing food containing at least one liquid component is particularly preferred. The packaging is typically constructed here as so-called composite packaging, which in principle consists of packaging laminates with a planar layered structure, particularly cardboard / plastic composite laminates.

[0003] Paperboard composite packaging and the paperboard / plastic composite laminate used to manufacture such packaging have paperboard layers that provide the packaging with basic stability and thus its basic structure. The paperboard layers thus constitute the supporting layer that provides the structure, and this supporting layer is at least authoritatively involved in determining, but especially very importantly, the flexural stiffness of the packaging laminate. In other words, the packaging laminate and the packaging thus manufactured retain their shape because of the supporting layer that provides the structure. In addition, an outer, especially thermoplastic, plastic layer, such as a plastic layer made of polyethylene (PE), is usually provided. The plastic layer protects the paperboard from moisture and prevents food from receiving unwanted substances from the packaging. Furthermore, other layers, such as an aluminum layer, may be provided to prevent the diffusion of oxygen and other gases through the packaging laminate. Moreover, the outer thermoplastic layer allows for sealing the packaging laminate, for closing the packaging, and for attaching accessories such as pourers to the packaging. Furthermore, the packaging laminate is often printed with decorations, which can be printed on the outer plastic layer, wherein the decorations are typically much thinner than the actual outer plastic layer. Packaging laminates may also include other layers, such as an aluminum layer, which provides a barrier against gases and light.

[0004] Packaging laminates can be supplied as webs or continuous materials, especially as rolls, allowing packages to be formed directly without first producing cut pieces. Here, the roll is first bent and formed into a flexible tube along its longitudinal edge, and then liquid-sealed in the longitudinal direction. The liquid-sealed transverse seams are then sealed at regular intervals. Products can be individually filled into the open upper flexible tubes before each tube is sealed into a package through the next transverse seam.

[0005] Alternatively, the packaging laminate can be cut longitudinally and / or laterally before the package is formed, thereby producing so-called cut pieces. These cut pieces can be further processed into so-called package shell blanks in the form of package housings or sleeves. For this purpose, the longitudinal edges are overlapped and sealed to each other in the form of a longitudinally sealed seam. This results in a tubular package shell as needed, which is folded flat and stacked for further processing in another location, particularly in a filling machine. In the filling machine, the formed and filled packages can be manufactured from the package shells.

[0006] The flattened packaging shells are transferred as a stack to the filling machine's hopper and unfolded sequentially. This unfolding occurs along pre-folded fold lines where the packaging laminates can be easily bent or folded. These fold lines are also known as groove lines. The unfolded packaging shells are then folded, pressed, and sealed at one end, i.e., closed. The closed end of the packaging shell can then form the bottom or top of the package. The resulting one-sided open package is then fed into the filling machine, where it is preheated with hot sterile air and then typically sterilized with hydrogen peroxide and dried with sterile air. The sterile package is then filled, and the opening of the filled package is subsequently sealed before the package leaves the filling machine.

[0007] To enable reliable, rapid, and simple folding of package material cutouts into the outer shell, bottom of the package body, and head of the package, the package material web is provided with grooves on which the package material cutouts can be folded. Here, the grooves are typically embossed into the package material web using a groove-pressing tool, wherein the package material web has a recess along the groove on one side facing the package material web and a protrusion on the opposite side facing the package material web.

[0008] Especially numerous grooves are provided in the top and bottom areas of the packaging, as these grooves are necessary for folding the packaging at the top and bottom. In addition to the grooves, in many cases, a tipper-like element is installed in the top area of ​​the packaging, through which the contents of the package can be later emptied. Here, the tipper typically has a base for guiding the product through and a flange for connecting the tipper to the thermoplastic layer of the packaging laminate. Furthermore, a cap may be provided, which screws onto the base to close the tipper. Typically, a hole is provided in the packaging laminate, and the tipper is installed into this hole from the subsequent inner or outer side of the packaging. Here, the hole can be coated with another material to close the hole in the packaging laminate, for example, through a film that can be easily opened if needed.

[0009] Typically, the pourer is installed by placing its flange around a hole and then ultrasonically welding it to the thermoplastic layer of the adjacent packaging laminate. For this purpose, the packaging laminate and the pourer are pressed between an ultrasonic generator that generates ultrasound and an anvil, and are partially heated by the ultrasound, causing the flange of the packaging laminate and / or the adjacent layer to melt or at least soften. Due to the pressure applied to the packaging laminate and the pourer, the pourer and the packaging laminate are welded together. However, damage to the adjacent groove lines always occurs. Here, the packaging laminate may crack, become unsealed, and / or delaminate.

[0010] Similar problems may arise when sealing other components on the packaging laminate, such as when sealing lids, cutlery, straws, and giveaways. However, corresponding problems may also occur when sealing components to other workpieces. The workpiece is preferably at least partially planar, and can be constructed in the form of a laminate. It is preferable that at least this surface is partially composed of thermoplastic. Furthermore, the aforementioned problems particularly arise when there is an interruption in the workpiece adjacent to the seal, which hinders the unimpeded conduction of vibration and / or heat. Summary of the Invention

[0011] Therefore, the object of the present invention is to design and improve sealing devices and methods of the type described at the beginning and those previously detailed, so that, for example in the area of ​​the groove line, damage and non-sealing of the workpiece, such as the packaging laminate, can be avoided by means of ultrasonic sealing of the fitting element, such as the tilter, to the workpiece or packaging laminate.

[0012] This objective is achieved in the sealing device according to the preamble of claim 1, wherein at least one pair of clamping members, which are paired with each other and decoupled from the sealing surface, are provided on opposite sides of the sealing gap for clamping the workpiece in the closed position, and the at least one pair of clamping members are provided outside the sealing surface relative to the equipping element, in particular the tilter, when viewed along the direction of the sealing gap.

[0013] Furthermore, the objective according to claim 9 is achieved by a method for sealing a fitting element on a workpiece, particularly a workpiece in the form of a composite laminate, by means of ultrasound, preferably according to any one of claims 1 to 8, wherein the fitting element and the workpiece are respectively introduced at least partially into a sealing gap between an ultrasonic generator and an anvil, and there are compressed between the ultrasonic generator and the anvil, wherein the compressed workpiece is clamped relative to the fitting element from opposite sides of the sealing gap outside the sealing surface between at least a pair of mutually mating clamping members, and wherein, when the workpiece is clamped, the sealing surface of the ultrasonic generator, which is decoupled from the vibration of the at least a pair of clamping members, transmits ultrasonic waves to the compressed fitting element and / or the compressed workpiece, and hereby seals the fitting element and the workpiece to each other.

[0014] According to the invention, not only workpieces, especially those in the form of packaging laminates, but also equipment elements, especially those in the form of tilters, are pressed between an ultrasonic generator and an anvil to seal the equipment elements with the workpiece. Furthermore, the workpiece is also clamped between clamping members disposed on opposite sides of the sealing gap, and thus arranged on opposite sides of the workpiece contained within the sealing gap. During the sealing of the workpiece and equipment element, the ultrasonic generator and anvil are in the closed position, and the clamping members can also close to clamp the workpiece. Here, the clamping members are decoupled from the vibration of the ultrasonic generator, such that the ultrasonic waves transmitted to the workpiece through the clamping members are negligible compared to those transmitted through the sealing surface of the ultrasonic generator.

[0015] Furthermore, the clamping element is positioned outside the area to be sealed relative to the mounting element. This does not necessarily mean that the clamping element clamps the workpiece outside the flange of the mounting element. It can also be configured such that the clamping element clamps the workpiece together with the flange of the mounting element, specifically outside the area to be welded, or on the one hand, at least outside the contact surface between the workpiece and / or the mounting element, and on the other hand, outside the sealing surface of the ultrasonic generator. Outside the sealing surface means that the clamping surface of the clamping element in contact with the workpiece is not arranged on the side of the sealing surface pointing towards the central area of ​​the mounting element, but on the opposite side of the sealing surface.

[0016] According to this method, the workpiece and the mounting element are first introduced, at least partially, into a sealing gap between the ultrasonic generator and the anvil, and thereby compressed between the ultrasonic generator and the anvil. In any case, during the ultrasonic sealing of the workpiece and the mounting element, the compressed workpiece is clamped between at least one pair of mating clamping elements from opposite sides of the sealing gap, and specifically at a position relative to the mounting element outside the sealing surface of the ultrasonic generator. The ultrasonic generator, decoupled from the vibration of the clamping elements, can then seal the workpiece compressed between the ultrasonic generator and the anvil and the mounting element, which is also compressed between the ultrasonic generator and the anvil, to each other. This is achieved by transmitting ultrasonic vibrations to the compressed workpiece and / or the compressed mounting element through the sealing surface of the ultrasonic generator.

[0017] Finally, the energy required for sealing is locally introduced into the workpiece and / or mounting components via ultrasound. However, even though the energy density in the workpiece decreases due to dissipation with increasing distance from the sealing surface of the ultrasonic generator, this corresponding energy is available not only in the area of ​​the sealed joint but also radiated into other areas of the workpiece. However, clamping the workpiece completely and specifically terminates energy conduction within the workpiece, or in any case significantly reduces energy conduction. Energy cannot or cannot easily pass through the clamped area.

[0018] Here, energy propagates primarily through the workpiece via thermal conduction and via ultrasonic vibration. In the area where the workpiece is clamped, the conduction of ultrasonic vibration is blocked because the clamped area cannot or can only vibrate to a limited extent due to the clamping. The clamping area of ​​the workpiece is therefore an obstacle to its vibration. Furthermore, the clamping element can absorb a significant portion of the heat conducted by the workpiece. Therefore, only a significantly smaller portion of the heat is conducted beyond the clamping area of ​​the workpiece. Thus, thermal conduction itself is not blocked by the clamping. Heat is also directed beyond the clamping area of ​​the workpiece. However, through contact with the clamping element, a significant portion of the heat conducted to the clamping area is removed from the workpiece.

[0019] Therefore, clamping the workpiece prevents, for example, the high energy density that could be conducted to the adjacent grooves of the workpiece. That is, the grooves also act as an obstacle to the propagation of ultrasonic vibrations within the workpiece, because the workpiece is more compact and rigid in the grooved region, thus conducting vibrations significantly worse in the grooved region than in the adjacent region. Consequently, vibrations reaching the grooves are either partially absorbed or partially reflected by the grooves, directly resulting in mechanical loads on the grooves and indirectly leading to heat generation at the grooves. In addition to this heat generation, heat may also be transferred to the grooves via thermal conduction. Without clamping in this manner, all of these factors could individually or collectively lead to damage to the grooves, potentially resulting in workpiece desealing, cracking, and delamination.

[0020] The processes previously described for grooves can also occur at other discontinuities in the workpiece. These discontinuities can be bends, curls, shrinkage, openings, holes, connections, etc. These elements can also be obstacles to the unimpeded propagation of ultrasonic vibrations and / or temperature within the workpiece. If necessary, the workpiece can also be a composite laminate. According to the invention, in the case of these workpieces, undesirable delamination, i.e., the separation of the individual layers of the laminate, can be prevented as much as possible.

[0021] Furthermore, it has been proven in principle that the clamping force of at least one pair of mating clamping elements is perfectly suitable, and this clamping force can be between 10N and 150N for typical applications. However, the clamping force is particularly preferably between 25N and 100N or between 45N and 70N.

[0022] For better understanding and to avoid unnecessary repetition, the sealing device and method are described together below without making a detailed distinction between them. However, those skilled in the art will, based on the context, derive the features that are particularly preferred for the sealing device and method, respectively.

[0023] In a first particularly preferred design of the sealing device, the fitting element is constructed as a tipper and / or the workpiece is constructed as a packaging laminate, particularly in the form of a cardboard / plastic composite laminate. In these cases, the advantages of the sealing device are utilized to a particular degree, as otherwise damage to the workpiece might be particularly easy. Here, a tipper can also be used without a packaging laminate, and vice versa. Furthermore, advantages arise to a particular degree when using workpieces in the form of cardboard / plastic composite laminates. That is, these workpieces are particularly prone to delamination. Moreover, such workpieces are often first connected with the grooved lines and then with the fitting element to manufacture cardboard composite packaging. Therefore, the installation of the fitting element may negatively impact the grooved lines. The corresponding workpiece, particularly the cardboard / plastic composite laminate, has a cardboard layer that should act as a supporting layer providing the structure, giving the packaging basic stability, and thus providing the basic structure. Furthermore, an outer thermoplastic layer, for example made of polyethylene (PE), is preferably provided to enable sealing of the workpiece and to protect the cardboard from moisture. Additionally, other layers, such as an aluminum layer, can be provided to prevent the diffusion of oxygen and other gases through the workpiece. In addition, the workpiece may have decorations or similar designs printed on at least one side.

[0024] Alternatively or additionally, at least one pair of clamping elements may be arranged relative to the sealing gap at least substantially around the sealing surface. In this way, the sealing energy introduced by the sealing surface of the ultrasonic generator in the area equipped with the element cannot, or is not to a noteworthy degree, diffuse outward in all directions. For simplicity, and to avoid stress peaks in the workpiece, it is further suitable that at least one pair of clamping elements are arranged at least substantially circularly around the sealing surface.

[0025] For example, at least two pairs of mating clamping members can be provided on opposite sides of the sealing gap to clamp the workpiece in the closed position. This is suitable when the groove line is present adjacent to the mounting element only in specific directions. Only in these directions must the propagation of energy introduced during sealing be limited. The same applies when the workpiece has a fibrous layer, especially a layer made of cardboard, with a preferred fiber direction, also referred to as the main fiber direction. Thus, vibrations introduced into the workpiece are preferably transmitted along the main fiber direction. Therefore, it is only necessary to limit the propagation of energy introduced during sealing in this main fiber direction, more precisely, on both sides originating from the central region of the mounting element as needed. Here, at least another pair of clamping members is also vibrationally decoupled relative to the sealing surface. No additional vibration should be transmitted to the workpiece through the clamping members to a noteworthy degree. Here, unrelatedly, it is particularly suitable that the at least two pairs of clamping members are positioned outside the sealing surface on opposite sides relative to the mounting element and viewed along the direction of the sealing gap. Thus, excessive propagation of sealing energy in opposite directions within the workpiece can be prevented.

[0026] If at least one of the clamping elements in at least one pair has an elastic portion, further vibration decoupling from the ultrasonic generator can be achieved. That is, at least a large portion of the vibration of the ultrasonic generator is absorbed by the elastic material and thus removed from the system. Alternatively or additionally, reliable clamping of the workpiece can be achieved as needed. The elastic portion of the clamping element can help compensate for unevenness of the workpiece in the clamping area. Therefore, uniform and sufficient clamping of the workpiece can be achieved. Here, it is particularly simple and suitable that the elastic portion provides a clamping surface for clamping at least one clamping element for clamping the workpiece. Alternatively, the clamping surface should preferably be connected to the other parts of the clamping element only through the elastic portion. Furthermore, at least a portion of the vibrational energy can be removed from the workpiece through the elastic portion of the clamping element. The vibration of the workpiece causes the elastic portion to vibrate, and the elastic portion converts the vibration into heat due to internal friction. The corresponding heat can then be released to the surrounding environment or other parts of the clamping element. Here, it is entirely appropriate in principle that the elastic portion is made of a material with a small elastic modulus. Here, the elastic modulus of the material should preferably be less than 5.0 N / mm. 2 Preferably less than 2.5 N / mm 2 Especially less than 1.0 N / mm 2 Alternatively, the elastic portion can have a Shore hardness of 20 to 100, particularly 40 to 80. At this hardness, suitable vibration damping characteristics are achieved.

[0027] For simplicity, at least one of the clamping elements corresponding to the anvil can be constructed as part of the anvil. This is especially true when the corresponding clamping element has a resilient portion. Additional vibration decoupling can then be achieved. However, vibration is typically transmitted to the anvil via the sealing element and / or the workpiece through the seal itself. Therefore, when the clamping element is implemented spaced apart from the anvil in a direction at least substantially parallel to the sealing gap, additional vibration decoupling of at least one clamping element corresponding to the anvil can be largely achieved. Vibration cannot be transmitted through this spacing, especially when air or the like is provided between the anvil and the clamping element. Regardless of this, it is also suitable to make the corresponding clamping element have a resilient portion. Vibration decoupling, at least relative to the workpiece, can then be achieved. Vibration decoupling also results in the desired vibration reduction in the clamping area of ​​the workpiece.

[0028] Comprehensive vibration decoupling is particularly important for ultrasonic generators. Therefore, it is suitable that at least one of the at least one pair of clamping members corresponding to the ultrasonic generator is spaced apart from the ultrasonic generator in a direction at least substantially parallel to the sealing gap. Thus, vibration cannot be transmitted through this spacing, especially when air or the like is provided between the anvil and the clamping member.

[0029] Alternatively or additionally, to dampen vibrations, a vibration damper in the form of a robust component with increased inertia can also be used. This is possible in that at least one of a pair of clamping elements is fixed to a vibration damper with a mass between 50g and 400g, preferably between 80g and 300g, and especially between 125g and 225g. Here, the clamping element can be at least one clamping element corresponding to an anvil and / or at least one clamping element corresponding to an ultrasonic generator. However, the latter may be particularly suitable here because the ultrasonic waves are generated by the ultrasonic generator and are also transmitted by the ultrasonic generator to the workpiece and / or the mounting element. In order to enable vibration damping, especially by inertia, it is suitable that the vibration damper has a mass of at least 50,000 N / mm². 2 Preferably at least 100,000 N / mm 2 Especially at least 150,000 N / mm 2 The material composition of the elastic modulus.

[0030] In addition, for the purpose of uniform vibration damping, at least one of the at least one pair of clamping elements may be disposed on a vibration damper that is arranged at least substantially circumferentially around the ultrasonic generator and / or the sealing surface. Here, the at least one clamping element may also correspond to the anvil and / or the ultrasonic generator. Since ultrasonic waves are generated by the ultrasonic generator as described above and transmitted from the sealing surface of the ultrasonic generator to the workpiece and / or the mounting element, it is also particularly suitable here when the corresponding clamping element corresponds to the ultrasonic generator.

[0031] To achieve the best possible clamping of the workpiece while taking into account possible tolerances or other deviations, it is suitable, if necessary, that at least one clamping element be adjustable, preferably oscillating, or tiltable. This is particularly suitable when at least one of the at least one pair of clamping elements is configured to oscillate relative to the ultrasonic generator and / or anvil about at least one oscillation axis oriented at least substantially parallel to the sealing gap. This achieves good contact between the clamping element and the workpiece. Furthermore, this contact can be achieved particularly reliably when a clamping element is provided that can oscillate freely about the oscillation axis. Since the ultrasonic generator produces vibrations, the corresponding clamping element preferably corresponds to the ultrasonic generator. Alternatively or additionally, for vibration damping, it is particularly preferred that the clamping element, together with a vibration damper, be configured to oscillate about at least one oscillation axis.

[0032] To ensure reliable and proper clamping, at least one of the clamping elements in at least one pair can be spring-loaded, at least substantially, in the direction of the sealing gap. This allows the clamping force to be predetermined or adjusted to a certain extent. For simplicity, it is arranged here that the clamping element is spring-loaded together with the vibration damper. In this case, particularly good results can also be obtained if the clamping element corresponds to an ultrasonic generator that causes vibration.

[0033] In a first particularly preferred design of this method, a tipper is used as an accessory element and / or a packaging laminate, especially in the form of a cardboard / plastic composite laminate, is used as the workpiece. In these cases, the advantages of this method are particularly utilized, as damage to the workpiece might otherwise occur particularly easily. Here, a tipper can also be used without a packaging laminate, and vice versa. Furthermore, advantages are particularly evident when using workpieces in the form of cardboard / plastic composite laminates. That is, these workpieces are particularly prone to delamination. Moreover, such workpieces are often first connected with the corrugated lines and then with the accessory element to manufacture cardboard composite packaging. Therefore, the installation of the accessory element may negatively affect the corrugated lines. The corresponding workpiece, especially the cardboard / plastic composite laminate, has a cardboard layer that should act as a supporting layer to provide basic stability to the packaging and thus provide the basic structure. Furthermore, an outer thermoplastic layer, for example made of polyethylene (PE), is preferably provided to seal the workpiece and protect the cardboard from moisture. Additionally, other layers, such as an aluminum layer, can be provided to prevent the diffusion of oxygen and other gases through the workpiece. In addition, the workpiece may have decorations or similar designs printed on at least one side.

[0034] Alternatively or additionally, the workpiece can be clamped by at least one pair of clamping members extending longitudinally along the clamping members, at least primarily transverse to the main fiber direction of the workpiece. Thus, the conduction of vibration and heat, primarily in the fiber direction, is reliably interrupted, or at least significantly reduced, by the corresponding clamping of the clamping members and the workpiece. This is particularly true when the longitudinal extension of the clamping members is oriented, especially at least substantially perpendicular to, the main fiber direction of the workpiece, particularly the paperboard. Here, in many cases, this is true that not all fibers of the workpiece, particularly not all fibers of the paperboard layer, are oriented parallel to each other. However, nevertheless, most and / or the longest fibers of the workpiece, particularly the paperboard layer, are generally oriented at least approximately parallel to each other. This direction is then considered the main fiber direction.

[0035] Alternatively or additionally, it is advantageous that the workpiece is clamped between the mounting element and the groove line of the workpiece by a clamping element. This prevents the unimpeded conduction of energy introduced into the workpiece as vibration and heat during sealing from the workpiece toward the groove line, which could lead to damage to the groove line and / or the workpiece. By clamping the workpiece with the clamping element, the conduction of energy is limited to at least a significant extent.

[0036] Because in many cases the grooves are arranged on opposite sides of the mounting elements, especially when viewed along the main fiber direction, it is suitable that the workpiece be clamped by clamping elements located on opposite sides of the mounting elements, especially when viewed along the main fiber direction. In other directions, such as perpendicular to the main fiber direction, clamping may not occur to protect the workpiece there. This may be suitable when the grooves are spaced at intervals in these directions, or when energy conduction perpendicular to the main fiber direction is so small that energy conduction can be accepted without concern for damage to the grooves there.

[0037] If the workpiece is clamped at least substantially around the clamping element, the propagation of energy introduced into the workpiece during sealing can be limited particularly easily and reliably. Propagation can then be limited in all directions. This can be achieved particularly simply and uniformly if the clamping of the workpiece is at least substantially circular around the ultrasonic generator and / or the sealing surface.

[0038] To reduce overall vibration and thus remove it from the system, at least one of the clamping elements in a pair may have at least one elastic portion. The ultrasonic vibration can then be at least partially absorbed by these elastic portions during sealing. However, for this to be achieved, appropriate contact must be established with the workpiece to transmit the vibration to the elastic portion. This can be particularly easily achieved if the elastic portion provides the clamping surface of the clamping element. Alternatively, the clamping surface should preferably be connected to the other parts of the clamping element only through the elastic portion. The vibration of the workpiece causes the elastic portion to vibrate, and the elastic portion converts the vibration into heat due to internal friction. The corresponding heat can then be released to the surrounding environment or other parts of the clamping element. Here, it is perfectly suitable in principle that the elastic portion is made of a material with a low modulus of elasticity. Preferably, the modulus of elasticity of the material should be less than 5.0 N / mm². 2 Preferably less than 2.5 N / mm 2 Especially less than 1.0 N / mm 2 Alternatively, the elastic portion can have a Shore hardness of 20 to 100, particularly 40 to 80. At this hardness, suitable vibration damping characteristics are achieved.

[0039] Vibration damping can also be provided as an alternative or addition to corresponding vibration absorption. During absorption, vibration is converted into elastic deformation of the elastic portion, and thus the corresponding energy is dissipated. Conversely, during damping, utilizing the inertia of sufficient mass of the damper, the damper must also be in contact with the workpiece in such a way that vibration can be transmitted from the workpiece to the damper. According to this method, vibration transmitted from the ultrasonic generator to at least one of the at least one pair of clamping members can be damped by a damper supporting the clamping member, the mass of which is between 50g and 400g, preferably between 80g and 300g, and particularly between 125g and 225g. This results in sufficient energy dissipation within the system to protect adjacent groove lines from the effects of this energy. For damping to be effective by the damper, especially by inertia, it is suitable that the damper has a mass of at least 50,000 N / mm². 2 Preferably at least 100,000 N / mm 2 Especially at least 150,000 N / mm 2 The material is composed of elastic modulus.

[0040] Alternatively or additionally, it is equally suitable that the vibration transmitted from the ultrasonic generator to at least one of the at least one pair of clamping members is damped by a vibration damper supporting the clamping member and surrounding the ultrasonic generator. Thus, the vibration energy is compensated for when the vibration introduced during sealing has different transmission characteristics in different directions. This compensation is particularly largely achieved when the vibration damper is constructed to at least substantially annularly surround the ultrasonic generator.

[0041] To ensure adequate contact between the clamping elements and the workpiece, it is suitable that at least one of the at least two clamping elements oscillates about a swing axis that is at least substantially parallel to the orientation of the sealing gap for clamping. This allows inaccuracies arising during movement or within the workpiece itself to be compensated, which can contribute to uniform clamping as intended. For simplicity and better vibration damping, at least one clamping element may oscillate together with a damper about a swing axis that is at least substantially parallel to the orientation of the sealing gap.

[0042] At least one of the at least one pair of clamping members can at least partially clamp the workpiece using a clamping force comprised at least partially of the restoring force of at least one spring member. Therefore, it is possible to ensure, without problems, that the workpiece is clamped with sufficient clamping force to prevent the propagation of energy introduced into the workpiece during sealing, without the clamping force being so large as to damage the workpiece during clamping. It is suitable here that, during clamping, at least one clamping member, together with the damper, is loaded with a restoring force via at least one spring member. This simultaneously ensures that vibrations transmitted from the workpiece to the clamping member are reliably and appropriately transmitted to the damper. Attached Figure Description

[0043] The invention will now be explained with the aid of the accompanying drawings, which illustrate only one embodiment. The drawings show:

[0044] Figure 1A-1B A three-dimensional view of the sealing device according to the invention in the open position;

[0045] Figure 2 Figure 1 shows a top view of the anvil of the sealing device.

[0046] Figure 3 Figure 1 shows a top view of the ultrasonic generator and vibration damper of the sealing device; and

[0047] Figures 4A-4C The sealing device of FIG1 in the open and closed positions during the method according to the invention. Detailed Implementation

[0048] exist Figure 1A and 1B The diagram shows a sealing device 1 for ultrasonically sealing a pouring device 2 to a workpiece 3, particularly a cardboard / plastic composite laminate, on a packaging laminate. The sealing device 1 provides a sealing gap 4 into which portions of the workpiece 3 and the device 2 can be introduced. An ultrasonic generator 5 is positioned on one side of the sealing gap 4, generating ultrasonic vibrations that are transmitted to the workpiece 3 via a sealing surface 6. Opposite the ultrasonic generator 5, an anvil 7 is arranged on the other side of the sealing gap 4, receiving a flange 9 of the device 2 in a receiving portion 8. The ultrasonic generator 5 then presses the workpiece 3 against the flange 9 while simultaneously transmitting ultrasonic vibrations to the workpiece 3, thereby sealing the workpiece 3 in the corresponding position against the flange 9 of the device 2.

[0049] Simultaneously, the clamping elements 10 and 11 of the two pairs of mating clamping elements 10 and 11 clamp the workpiece 3 between each other to prevent vibrations introduced into the workpiece 3 and the heat induced therefrom during sealing from being conducted almost unimpeded through the workpiece 3 toward the adjacent groove line 12. Otherwise, the energy generated by vibration and heat in the workpiece 3 could damage the groove line 12. The workpiece 3 might, for example, crack, become unsealed, and / or delaminate in the area of ​​the groove line 12.

[0050] In the region of the clamped workpiece 3, heat and vibration are transmitted from the workpiece 3 to the mating clamping members 10, 11, and therefore cannot be transmitted further outward from the workpiece 3 to the extent described above. Here, the clamping members 10, 11 are respectively disposed opposite each other on both sides of the sealing gap 4, and therefore correspond either to the anvil 7 or to the ultrasonic generator 5. The clamping member 11 corresponding to the anvil 7 is made of an elastic material, but not necessarily silicone. Therefore, the elastic portion 13 of the clamping member 11 also constitutes the clamping surface 14 of the corresponding clamping member 11. In this way, unimpeded transmission of vibration from the workpiece 3 to the anvil 7, or from the anvil 7 to the workpiece 3 through the clamping member 11, is prevented. These vibrations are partially received by the clamping member 11, and therein, elastic deformation occurs, through which vibrational energy is absorbed in the clamping member 11.

[0051] Furthermore, vibrations transmitted to the anvil 7 via the equipped element 2 during sealing cannot, or can only be limitedly, transmitted to the workpiece 3 via the clamping member 11. These vibrations also cause elastic deformation of the clamping member 11, which is made of an elastic material, and thus cause the corresponding absorption of energy, which can no longer be transmitted from the anvil 7 to the workpiece 3 via the associated clamping member 11. Finally, vibration decoupling between the anvil 7 and the workpiece 3 is achieved through the clamping member 11 corresponding to the anvil 7.

[0052] The clamping member 10 corresponding to the ultrasonic generator 5 is held by a vibration damper 15, which is spaced apart from the ultrasonic generator 5 and thus arranged in a vibration-decoupled manner from the ultrasonic generator 5 and its sealing surface 6. The vibration damper 15 is held freely on a swing axis 16. Here, the swing axis 16 extends at least substantially parallel to the sealing gap 4. Therefore, the clamping surface 14 of the clamping member 10 is always oriented parallel to the workpiece 3 so as to uniformly clamp the workpiece 3 on the clamping surface 14.

[0053] The swing axis 16 and therefore the damper 15 are adjustable relative to the ultrasonic generator 5 and its sealing surface 6 in a direction at least substantially perpendicular to the sealing gap 4. Here, the damper 15 is spring-loaded in the direction of the sealing gap 4. In other words, the damper 15 is spaced apart from the sealing gap 4, overcoming the restoring force of the spring member 17. Therefore, the maximum clamping force between the mating clamping members 10, 11 is limited.

[0054] exist Figure 2The anvil 7 is shown in a top view from the sealing gap 4. The anvil 7 has a receiving portion 8 in which the flange 9 of the mounting element 2 is accommodated. When the mounting element 2 is sealed with the workpiece 3, the mounting element 2 is pushed towards the receiving portion 8 of the anvil 7 by the ultrasonic generator 5 through the workpiece 3. An opening 18 is provided in the receiving portion 8 of the anvil 7, through which negative pressure in the receiving portion 8 can be extracted, so as to reliably hold the mounting element 2 in the receiving portion 8 of the anvil 7. A clamping member 11 corresponding to the anvil 7 is arranged on the opposite side of the receiving portion 8 and spaced apart from the receiving portion 8. The clamping member 11 protrudes slightly into the sealing gap 4 relative to the receiving portion 8. However, because the clamping member 11 is made of an elastic material, the clamping member 11 can be slightly compressed, for example, so that the clamping member 11 no longer protrudes relative to the receiving portion 8, or no longer protrudes that far. Therefore, the clamping surface 14 of the clamping member 11 can be aligned with the receiving portion 8 of the anvil 7 and / or with the flange 9 of the equipped element 2.

[0055] exist Figure 3 The diagram shows a top view of the ultrasonic generator 5 together with the vibration damper 15, viewed from the sealing gap 4. The ultrasonic generator 5 has a central receiving portion 19 for receiving the portion of the mounting element 2 that protrudes outward beyond the workpiece 3. This portion of the mounting element 2 preferably includes a helical fixing portion 20. The sealing surface 6 of the ultrasonic generator 5 is arranged around the receiving portion 19. The sealing surface 6 of the ultrasonic generator 5 shown, and preferably in this respect, is annular. The ultrasonic generator 5 presses against the workpiece 3, which is arranged on a flange 9 of the same annular construction, with the sealing surface 6 to apply a connection using ultrasound, and thereby seal, i.e., weld. The vibration damper 15 is arranged around the ultrasonic generator 5 and the sealing surface 6, and spaced apart from the ultrasonic generator 5. This vibration damper supports two clamping members 10, which are constructed to mate with clamping members 11 corresponding to the anvil 7. The clamping members 10 corresponding to the ultrasonic generator 5 are robustly constructed and held by the even more robust vibration damper 15. In the sealing device 1 shown and preferred in this regard, the clamping member 10 and the damper 15 corresponding to the ultrasonic generator 5 are constructed of metal, especially steel.

[0056] The damper 15 is arranged around the ultrasonic generator 5 and the sealing surface 6, and is held in a mating recess of the sealing device 1 by two pins 21. The pins 21 define a swing axis 16 about which the damper 15 can swing relative to the recess 22 at least substantially parallel to the sealing gap 4. The recess 22 can be adjusted slightly back and forth relative to the sealing surface 6 in the direction of the sealing gap 4. Because the recess 22 and / or the damper 15 are spring-loaded by the spring member 17, the damper 15 overcomes the restoring force of the spring member 17 to achieve adjustment relative to the ultrasonic generator 5 and away from the anvil 7.

[0057] exist Figures 4A-4C The image shows the different positions of the sealing device 1 during the sealing method. Figure 4A The diagram shows a sealing device 1 with an ultrasonic generator 5 and an anvil 7 in the open position, in which the mounting element 2 can be introduced into the sealing gap 4 and inserted into the mating receiving portion 8 via a flange 9. The mounting element 2 is held in the position shown by applying negative pressure to the receiving portion 8.

[0058] After that, as Figure 4B As shown, workpiece 3 is introduced into sealing gap 4 such that mounting element 2 protrudes through mating hole 23 in workpiece 3. However, workpiece 3 can also be positioned accordingly first. Then, mounting element 2 can be introduced into sealing gap 4 and inserted there through mating hole 23 in workpiece 3. Afterwards, workpiece 3 surrounds hole 23 in workpiece 3, covering flange 9 of mounting element 2.

[0059] Now, the ultrasonic generator 5 and / or the anvil 7 can be adjusted relative to each other to the closed position, as in... Figure 4C As shown in the diagram. In the closed position, the ultrasonic generator 5 is activated and then transmits ultrasonic waves to the workpiece 3, which, together with the flange 9 of the mounting element 2, is heated in the area of ​​the flange 9, thus forming a material-fit connection between the workpiece 3 and the mounting element 2. Simultaneously, the workpiece 3 is clamped between clamping members 10 and 11, such that the ultrasonic waves and heat in the workpiece 3 are conducted outwards only within a limited range relative to the mounting element 2, beyond the clamping of the workpiece 3 between the clamping members 10 and 11. Therefore, the groove line 12 of the workpiece 3 in this area is not excessively damaged by the seal between the workpiece 3 and the mounting element 2. After sealing, the ultrasonic generator 5 and the anvil 7 are adjusted back to the open position relative to each other. The workpiece 3 with the sealed mounting element 2 can then be removed from the sealing gap 4. This cycle ends here, and can then be repeated to connect another workpiece 3 to the mounting element 2.

[0060] Description of Reference Numerals

[0061] 1 Sealing device

[0062] 2. Equipped with components (tilter)

[0063] 3. Workpiece (Packaging Laminate)

[0064] 4 sealing gap

[0065] 5. Ultrasonic generator

[0066] 6 sealing surfaces

[0067] 7 Anvils

[0068] 8. Accommodation

[0069] 9 flanges

[0070] 10 clamping components (ultrasonic generator)

[0071] 11 Clamping element (anvil)

[0072] 12 groove lines

[0073] 13 Elastic Part

[0074] 14 clamping surfaces

[0075] 15 shock absorbers

[0076] 16 Swing axis

[0077] 17 Springs

[0078] 18 openings

[0079] 19 Accommodation Department

[0080] 20 threaded fixing part

[0081] 21 pins

[0082] 22 notches

[0083] 23 holes

Claims

1. A sealing device (1) for sealing an accessory (2) onto a workpiece (3) by means of ultrasonic waves, the sealing device comprising: an ultrasonic generator (5) for generating ultrasonic waves; a sealing surface (6) for transmitting ultrasonic waves to the accessory (2) and / or the workpiece (3); an anvil (7) opposite to the ultrasonic generator (5); and an adjusting device for adjusting the ultrasonic generator (5) and the anvil (7) relative to each other from an open position to a closed position and back, said open position for at least partially introducing the accessory (2) and the workpiece (3) into a sealing gap (4) between the ultrasonic generator (5) and the anvil (7), said closed position for at least partially compressing the workpiece (3) and the accessory (2) between the sealing surface (6) of the ultrasonic generator (5) and the anvil (7) respectively during ultrasonic sealing. It is characterized in that At least one pair of clamping members (10, 11) are provided on the opposite side of the sealing gap (4) to clamp the workpiece (3) in the closed position, and the at least one pair of clamping members (10, 11) are provided outside the sealing surface (6) relative to the equipped element (2) and viewed in the direction along the sealing gap (4).

2. The sealing device according to claim 1, It is characterized in that The workpiece (3) is a composite laminate workpiece.

3. The sealing device according to claim 1, It is characterized in that The components (2) are configured as a tilter and / or the workpiece (3) are configured as a packaging laminate.

4. The sealing device according to claim 3, The at least one pair of clamping members (10, 11) are arranged to surround the sealing surface (6) at least substantially around the sealing gap (4).

5. The sealing device according to claim 3, The at least one pair of clamping members (10, 11) are arranged in a substantially circular manner around the sealing surface (6) relative to the sealing gap (4).

6. The sealing device according to claim 3, It is characterized in that The packaging laminate is in the form of a cardboard / plastic composite laminate.

7. The sealing device according to claim 1 or 3, It is characterized in that At least two pairs of clamping elements (10, 11) that are paired with each other and are vibrationally decoupled from the sealing surface (6) are arranged on opposite sides of the sealing gap (4) for clamping the workpiece (3) in the closed position, and the at least two pairs of clamping elements (10, 11) are arranged on opposite sides of the sealing surface (6) relative to the mounting element (2), when viewed along the direction of the sealing gap (4).

8. The sealing device according to claim 1, It is characterized in that At least one of the at least one pair of clamping members (10, 11) has an elastic portion (13) for decoupling from the vibration of the ultrasonic generator (5).

9. The sealing device according to claim 8, It is characterized in that The elastic portion (13) provides a clamping surface (14) for clamping the workpiece (3) with clamping members (10, 11).

10. The sealing device according to claim 1, It is characterized in that At least one of the at least pair of clamping elements (10, 11) corresponding to the anvil (7) is implemented as part of the anvil (7), or is implemented spaced apart from the anvil (7) in a direction at least substantially parallel to the sealing gap (4).

11. The sealing device according to claim 1, Its features are, At least one of the at least pair of clamping members (10, 11) having an elastic portion (13) and corresponding to the anvil (7) is implemented as part of the anvil (7).

12. The sealing device according to claim 1, Its features are, At least one of the at least one pair of clamping members (10, 11) corresponding to the ultrasonic generator (5) is spaced apart from the ultrasonic generator (5) in a direction at least substantially parallel to the sealing gap (4).

13. The sealing device according to claim 1, Its features are, At least one of at least one pair of clamping elements (10, 11) is fixed to the damper (15) having a mass between 50g and 400g, and / or at least one of at least one pair of clamping elements (10, 11) is disposed on the damper (15) which is disposed at least substantially circumferentially around the ultrasonic generator (5).

14. The sealing device according to claim 13, Its features are, At least one of the at least one pair of clamping elements (10, 11) corresponding to the clamping element (10, 11) of the ultrasonic generator (5) is fixed to the vibration damper (15).

15. The sealing device according to claim 13, Its features are, The shock absorber has a mass between 80g and 300g.

16. The sealing device according to claim 13, Its features are, The shock absorber has a mass between 125g and 225g.

17. The sealing device according to claim 13, Its features are, At least one of the at least one pair of clamping members (10, 11) corresponding to the ultrasonic generator (5) is disposed on a damper (15) that is arranged at least substantially annularly around the ultrasonic generator (5).

18. The sealing device according to claim 1, Its features are, At least one of the at least pair of clamping members (10, 11) is pivotally positioned about at least one swing axis (16) at least substantially parallel to the sealing gap (4) relative to the ultrasonic generator (5) and / or the anvil (7), and / or at least one of the at least pair of clamping members (10, 11) is spring-loaded at least substantially in the direction of the sealing gap (4).

19. The sealing device according to claim 1, Its features are, At least one of the at least pair of clamping members (10, 11) together with the damper (15) is arranged to swing freely about at least one swing axis (16) at least substantially parallel to the sealing gap (4) relative to the ultrasonic generator (5) and / or the anvil (7), and / or at least one of the at least pair of clamping members (10, 11) together with the damper (15) is spring-loaded at least substantially in the direction of the sealing gap (4).

20. The sealing device according to claim 18 or 19, It is characterized in that At least one of the at least one pair of clamping elements (10, 11) corresponds to the ultrasonic generator (5).

21. A method for sealing an assembly element (2) onto a workpiece (3) by means of ultrasonic waves, according to any one of claims 1 to 20. in, The component (2) and the workpiece (3) are respectively introduced at least partially into the sealing gap (4) between the ultrasonic generator (5) and the anvil (7), and are compressed there between the ultrasonic generator (5) and the anvil (7). Among them, the workpiece (3) pressed between at least one pair of mating clamping members (10, 11) on opposite sides of the sealing gap (4) is clamped relative to the mounting element (2) outside the sealing surface (6), and When the workpiece (3) is clamped, the sealing surface (6) of the ultrasonic generator (5), which is decoupled from the vibration of at least one pair of clamping elements (10, 11), transmits ultrasonic waves to the compressed equipment element (2) and / or the compressed workpiece (3), thereby sealing the equipment element (2) and the workpiece (3) with each other.

22. The method according to claim 21, in, The workpiece (3) is a workpiece in the form of a composite laminate.

23. The method according to claim 21, in, As an accessory (2), a tilter is used and / or as a workpiece (3), a packaging laminate is used, and / or Wherein, the workpiece (3) is clamped by at least one pair of clamping members (10, 11) in the longitudinal extension of the clamping members (10, 11), at least mainly transverse to the main fiber direction of the workpiece (3), and / or The workpiece (3) is clamped between the mounting element (2) and the groove line (12) of the workpiece (3).

24. The method according to claim 23, in, The packaging laminate is in the form of a cardboard / plastic composite laminate.

25. The method according to claim 23, in, The workpiece (3) is clamped by the clamping members (10, 11) of at least one pair of clamping members (10, 11) in the longitudinal extension of the clamping members (10, 11), at least substantially perpendicular to the main fiber direction of the workpiece (3).

26. The method according to claim 21 or 23, in, The workpiece (3) is clamped by clamping elements (10, 11) on the opposite side of the equipped element (2).

27. The method according to claim 26, in, The workpiece (3) is clamped by clamping elements (10, 11) at least substantially around the equipped element (2).

28. The method according to claim 27, in, The workpiece (3) is clamped by clamping elements (10, 11) at least substantially circularly around the equipped element (2).

29. The method according to claim 21, wherein, During sealing, at least one of the at least one pair of clamping elements (10, 11) absorbs vibration in the elastic portion (13).

30. The method according to claim 29, in, The elastic portion (13) is the elastic portion that provides the clamping surface (14).

31. The method according to claim 21, in, Vibrations transmitted from the ultrasonic generator (5) to at least one of the at least two clamping members (10, 11) are damped by a damper (15) supporting the clamping member (10, 11), the damper having a mass between 50g and 400g, and / or The vibration transmitted from the ultrasonic generator (5) to at least one of the at least one pair of clamping members (10, 11) is damped by a damper (15) that supports the clamping member (10) and surrounds the ultrasonic generator (5) at least substantially circumferentially.

32. The method according to claim 31, in, The mass of this shock absorber is between 80g and 300g.

33. The method according to claim 31, in, The mass of the shock absorber is between 125g and 225g.

34. The method according to claim 21, wherein, At least one of at least one pair of clamping elements (10, 11) swings about a swing axis (16) that is at least substantially parallel to the orientation of the sealing gap (4) for clamping.

35. The method according to claim 21, in, At least one of a pair of clamping elements (10, 11) and the damper (15) swing together about a swing axis (16) that is at least substantially parallel to the orientation of the sealing gap (4) for clamping.

36. The method according to claim 21, wherein, At least one of the at least pair of clamping members (10, 11) clamps the workpiece (3) at least partially by means of a clamping force formed by the restoring force of at least one spring member (17).

37. The method according to claim 21, wherein, The workpiece (3) is at least partially clamped by at least one of the at least one pair of clamping members (10, 11) and the damper (15) together using a clamping force formed by at least part of the restoring force of at least one spring member (17).

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