Transverse sealing system and method for transversely sealing a tube of packaging material

Abstract

A transverse seal (TS) system (110) for a packaging machine (100) is provided. The transverse seal system (110) includes an ultrasonic arrangement portion (400) arranged to face an outer surface of a tube (104) of packaging material from a first sealing direction (SD-1), the first sealing direction (SD-1) being perpendicular to a feed direction (FD) of the tube (104), the tube (104 including a longitudinal seal (LS) region (300) where at least two layers of packaging material overlap, and an anvil (402) arranged to face the outer surface from a second sealing direction (SD-2), the second sealing direction (SD-2) being opposite the first sealing direction (SD-1). The ultrasonic arrangement (400) comprises a sonotrode (404) that applies ultrasonic vibrations to at least partially melt the inner layer of the packaging material, a non-oscillating first pressure plate (406) adjacent to the sonotrode (402) and disposed upstream in the feed direction (FD) of the tube (104), and a non-oscillating second pressure plate (408) adjacent to the sonotrode (404) and disposed downstream in the feed direction (FD) of the tube (104), wherein the sonotrode (404) applies a TS-LS overlap pressure (TS-LS) to the TS-LS overlap region (308). The first pressure plate (406) is arranged to provide a first pressure (P1) to a first region (304) disposed upstream of the TS-LS overlap region (308) in the feed direction (FD), and the second pressure plate (408) is arranged to provide a second pressure (P2) to a second region (306) disposed downstream of the TS-LS overlap region (308) in the feed direction (FD).

Description

[Technical field]

[0001] This invention relates to the packaging arts, and more particularly to a transverse sealing system for a packaging machine, such as a roll-fed carton packer, and a method for transversely sealing a tube of packaging material. [Background technology]

[0002] Roll-fed carton filling machines, also called packaging machines, are well known. Roll-fed filling machines are one of two commonly known types of machines for producing carton packages. The other type of filling machine is the so-called blank-fed filling machine. Unlike roll-fed filling machines, in blank-fed filling machines, the longitudinal seal is pre-made. In other words, before feeding the packaging material to the blank-feed filling machine, the web of packaging material is formed into a tube and the longitudinal seal is provided as part of that process. In addition to the longitudinal seal being pre-made, the cut is also pre-made. The effect of the longitudinal seal and cut being done outside the filling machine is that fewer steps need to be done in the blank-feeding filling machine. On receiving the blank, i.e. the flat folded piece of tube, the blank is erected into a sleeve. One end of the sleeve is then closed and the food is filled into the sleeve through the open end. After filling, the other end of the sleeve is also closed. In most cases, after both ends of the sleeve are closed, it is folded into a package, e.g. a gable top package or a rectangular package.

[0003] In roll-fed filling machines, the packaging material is fed on a reel. After unwinding the packaging material, the web of packaging material is treated to remove bacteria, germs, and other unwanted microorganisms, for example using a hydrogen peroxide bath. Once the web is sterilized, it is formed into a tube. By placing the tube vertically, the food product can be continuously filled into the tube from above. Formation of the tube is achieved by placing one of the two outer longitudinal edges of the web over the other longitudinal edge. Heat and pressure melt the plastic layer of the packaging material and bond the two edges together. To protect the carton layer of the packaging material, and to achieve robustness and environmental benefits, strips of plastic material may be attached to the inside of the tube to prevent the food product from coming into contact with the carton layer through the end of the web placed inside the tube.

[0004] After the web is formed into a tube, and the tube is filled with the food, a transverse seal is applied to the bottom end of the tube. Often, two transverse seals are applied at the same time, which allows the tube to be cut at the same time. By cutting between the two transverse seals, the bottom part of the tube with a transverse seal on both ends can be separated and sent to the next process.

[0005] Lateral sealing can be done in different ways. If the packaging material has an aluminum foil layer, induction heating can be used to generate heat so that the plastic layer melts. If there is no aluminum foil, ultrasonic sealing can be used. In short, when using this technique, ultrasonic waves are generated by an ultrasonic device. These ultrasonic waves act on the plastic layer, generating heat, which melts the plastic layer.

[0006] Regardless of which transverse sealing technology is used, the transverse sealing process in the filling machine is a critical step. If the vertical sealing is not properly aligned with the transverse sealing system, the three-ply area, i.e. where the vertical and transverse seals meet, may not be aligned correctly, resulting in poor transverse sealing.

[0007] An issue to consider during the transverse sealing process is that the combination of heat and pressure can cause the molten plastic to migrate out of or within the transverse seal area, resulting in an insufficient seal. In other words, overheating or overpressurizing can lead to undesirable results. Balancing heat and pressure with the need to handle both two- and three-ply packaging materials is difficult. What's more, the transverse seal must be completed within a second, and sometimes even 0.2 seconds, which makes it even more challenging.

[0008] As mentioned above, roll-fed carton packaging machines have been in use for decades, with billions of packages produced annually by such machines. One example of such a packaging machine is the Tetra Pak A3 sold by Tetra Pak®.

[0009] Today's filling machines can produce carton packages at incredible speeds and to high quality standards, but there is still room for improvement. Greater control over the transverse sealing process would allow the use of packaging materials with a cleaner environmental impact. Greater control over the transverse sealing process would also make it possible to adapt the transverse sealing system to specific packaging materials, which is not possible with current technology. Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to at least partially overcome one or more of the above-mentioned limitations of the prior art. In particular, it is an object to provide a transverse sealing system that is less dependent on tube rotation, i.e. misalignment of the longitudinal seal. It is also an object to provide a system that is less dependent on the width of the longitudinal seal. It is also an object to reduce the risk of heat leakage from the transverse seal area to adjacent areas. It is also an object to reduce the risk of plastic lumps forming, resulting in insufficient transverse sealing. It is also an object to reduce the power consumption of the transverse sealing process. It is also an object to provide a transverse sealing system with high predictability of how the packaging material will be affected, thereby allowing reliable virtual modeling. It is also an object to increase the life span of the transverse sealing system, as an effect of reduced energy consumption (low amplitude, low power). It is also an object to increase the cooling time and use less energy for cooling. It is also an object to enable the transverse sealing system to be manufactured cost-effectively.

[0011] Throughout this specification, the term "sonotrode" is used in a broad sense and may more specifically be a horn connected to a transducer or converter so as to generate ultrasonic waves. The term "ultrasonic array" should also be interpreted broadly and should be understood to include, for example, a transducer with a horn and a transducer with a horn.

[0012] According to a first aspect, there is provided a transverse seal (TS) system for a packaging machine, the sealing system comprising: an ultrasonic arrangement positioned to face an outer surface of a tube of packaging material from a first sealing direction (SD-1), the first sealing direction (SD-1) being perpendicular to a feed direction (FD) of the tube, the tube comprising a longitudinal seal (LS) region where at least two layers of packaging material overlap; an anvil arranged to face the outer surface from a second sealing direction (SD-2), the second sealing direction (SD-2) being opposite to the first sealing direction (SD-1); The ultrasound placement unit is a sonotrode that applies ultrasonic vibrations such that the inner layer of the packaging material is at least partially melted; a first pressure plate disposed adjacent to the sonotrode and upstream in a feed direction (FD) of the tube, the first pressure plate being non-oscillating; a second pressure plate disposed adjacent to the sonotrode and downstream in the feed direction (FD) of the tube, the second pressure plate being optionally non-oscillating; The sonotrode may be arranged to provide a TS-LS overlap pressure (TS-LS P) in the TS-LS overlap region, a first pressure plate may be arranged to provide a first pressure (P1) in a first region arranged upstream of the TS-LS overlap region in the feed direction, and a second pressure plate may be arranged to provide a second pressure (P2) in a second region arranged downstream of the TS-LS overlap region in the feed direction (FD).

[0013] The advantage of having a first and a second pressure plate is that the transverse sealing process is less dependent on the rotation of the tube. By having these static elements next to the dynamic element, i.e. the sonotrode, sufficient sealing can be achieved for both two and three layer packaging materials.

[0014] The larger working area of ​​the transverse seal, i.e. covering both two- and three-ply sections, compared to currently used ultrasonic-based transverse sealing systems without static elements, allows for a thinner polymer layer, i.e. the inner layer of the packaging material. In other words, this larger working area reduces the risk of over-melting the inner layer and thus producing a package that does not meet quality standards. This reduction in risk allows the inner layer to be thinner while still maintaining the current seal quality. The thinner inner layer has both cost and sustainability benefits.

[0015] The transverse sealing system may be incorporated into roll-fed and blank-fed packaging machines. To that effect, the expression "tube" should be interpreted broadly. If the transverse sealing device is incorporated into a roll-fed packaging machine, the tube may be continuously produced from a web of packaging material and sealed at the bottom end. On the other hand, if the transverse sealing system is configured into a blank-fed packaging machine, the tube may be a sleeve with a pre-made longitudinal seal, used to produce one package. A number of sleeves folded flat may be placed in a magazine from which they are fed to the blank-fed packaging machine. The Tetra Pak® A3 Speed ​​is an example of a roll-fed packaging machine, and the Tetra Pak® R2 Machine is an example of a blank-fed packaging machine. A further example of a blank-fed packaging machine is the Tetra Pak® TT / 3.

[0016] The TS-LS overlap pressure (TS-LS P) may be greater than the first pressure (P1) and / or the second pressure (P2).

[0017] The first pressure plate may comprise a first sloped surface sloping away from the sonotrode and / or the second pressure plate may comprise a second sloped surface sloping away from the sonotrode.

[0018] The advantage of providing such a slope is that it reduces the risk of plastic lumps forming.

[0019] The anvil may comprise a first beveled surface sloping away from the sonotrode and / or may comprise a second beveled surface sloping away from the sonotrode.

[0020] The first and second pressure plates may extend along the entire width of the sonotrode.

[0021] The anvil may include a TS-LS anvil profile with a TS-LS anvil section positioned to fit the TS-LS overlap region of the tube, and a TS anvil profile with a TS anvil section positioned to fit the TS region of the tube.

[0022] The sonotrode may comprise a TS-LS sonotrode profile with a TS-LS sonotrode section positioned to fit into the TS-LS overlap region of the tube, and a TS sonotrode profile with a TS sonotrode section positioned to fit into the TS region of the tube.

[0023] The first and / or second pressure plate may comprise at least one ridge for blocking plastic mass formed at the edge of the TS-LS overlap region and / or the edge of the LS-strip region.

[0024] The first and / or second pressure plates may be spring loaded.

[0025] The lateral seal system further comprises: There may be a third pressure plate disposed in the groove of the sonotrode.

[0026] The packaging material comprises at least one cellulosic layer, such as a carton layer, and an inner polymeric layer, and is aluminum-free.

[0027] It is particularly beneficial for packaging materials that include cellulosic layers to have such a transverse seal system, since ultrasonic waves propagate over a wider area within the packaging material, as compared to, for example, a packaging material that is comprised solely of polymer-based layers.

[0028] Induction heat sealing requires a layer to interact with the inductor, such as an aluminum layer, which is often used in food packaging. However, the aluminum layer has environmental disadvantages. With ultrasonic sealing technology, the aluminum layer for the transverse seal is not needed. Therefore, the transverse sealing system has the advantage that more environmentally friendly packaging materials can be used in a more cost-effective and reliable manner.

[0029] According to a second aspect, the packaging machine comprises: a receptacle for packaging material; a food filling pipe arranged to fill the food into the tube; A transverse seal (TS) system according to a first aspect; Equipped with.

[0030] The packaging material receiver is capable of receiving a reel of packaging material and may be a magazine that holds the blanks.

[0031] According to a third aspect, there is provided a method of transversely sealing a tube of packaging material, the method comprising: feeding a tube of packaging material in a feed direction (FD); generating ultrasonic waves using a sonotrode included in the ultrasonic arrangement such that the inner layer of the packaging material in the transverse seal area is at least partially melted; forcing the tubes together at a lateral seal area by moving the transducer arrangement in a first sealing direction (SD-1) and moving the anvil in a second sealing direction (SD-2), the second sealing direction (SD-2) being opposite the first sealing direction (SD-1); The ultrasound placement unit is Sonotrode and a first pressure plate disposed adjacent to the sonotrode and upstream in a feed direction (FD) of the tube, the first pressure plate being non-oscillating; a second pressure plate disposed adjacent to the sonotrode and downstream in the feed direction (FD) of the tube, the second pressure plate being non-oscillating; Equipped with The sonotrode may be positioned to provide a TS-LS overlap pressure to the TS-LS overlap region, a first pressure plate may be positioned to provide a first pressure to a first region disposed upstream of the TS-LS overlap region in the feed direction (FD), and a second pressure plate may be positioned to provide a second pressure to a second region (306) disposed downstream of the TS-LS overlap region in the feed direction (FD).

[0032] The method further comprises: Relieving stress from the first region by a first inclined surface inclined away from the sonotrode; and / or relieving the stress from the second region by a second sloped surface inclined away from the sonotrode; The present invention may also include:

[0033] The method further comprises: Blocking the plastic mass formed at the edge of the TS-LS overlap area and / or the edge of the LS-strip area by at least one ridge provided on the first and / or second pressure plate.

[0034] The same features and advantages as discussed above with respect to the first aspect also apply to this third aspect.

[0035] Further objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and drawings.

[0036] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is an overall view of a roll-fed carton packing machine. [Diagram 2] 4A to 4C are cross-sectional views showing a lateral sealing process. [Figure 3A] FIG. 2 is a side view of a tube of packaging material. [Figure 3B] FIG. [Figure 4A] FIG. 2 shows a first example of an ultrasound placement section and an anvil. [Figure 4B] FIG. 13 shows a second example of an ultrasound placement section and anvil. [Figure 5A] FIG. 2 is a perspective view of a sonotrode. [Figure 5B] FIG. 2 is a side view of the sonotrode. [Figure 6] FIG. [Figure 7] 1 is a flow chart illustrating a method of transversely sealing a tube of packaging material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] FIG. 1 shows a schematic diagram of a packaging machine 100. In the illustrated example, the packaging machine 100 is a roll-fed carton packaging machine. The general principle of such machines is that a web 102 is formed from a roll of packaging material. Although not shown, if necessary to meet food safety regulations, the web 102 may be sterilized using a hydrogen peroxide bath, a low voltage electron beam (LVEB) device, or other device capable of reducing many unwanted microorganisms. After sterilization, the web 102 may be formed into a tube 104 using a longitudinal sealing device. Once the tube is formed, a product, for example milk, may be fed into the tube 104 via a product pipe 106 located in at least a portion of the tube 104.

[0039] To form a package 108 from the product-filled tube 104, a lateral seal system 110 can be used to perform a lateral seal at the bottom end of the tube. In general, the system 110 has two main functions: 1) to provide a lateral seal, i.e., to fuse together two opposing sides of the tube so that the product in the lower part of the tube located below the sealing system is separated from the product in the tube located above the sealing system, and 2) to cut the lower part of the tube so that the package 108 is formed. Alternatively, instead of performing the lateral seal and the cutting off of the lower part with one and the same system 110 as shown, the step of cutting off the lower part can be performed in a subsequent step by a separate device or by the consumer if the package is intended to be sold in a multipack.

[0040] In Fig. 2 the general principle of the transverse sealing system 110 is shown in more detail by way of example. As shown in Fig. 1, the tube 104 can be fed from above, since the product can be held in the tube. In the first stage, the sealing stage S, the first jaw with the sealing device 200 and the second jaw with the counter pressure device 202 are moved towards each other, the sealing device in a first sealing direction SD-1 and the counter pressure device 202 in a second sealing direction SD-2, so that the two opposite sides of the tube 104 are pressed towards each other. To perform the transverse seal, heat can be provided by inducing eddy currents in the packaging material while the two opposite sides are pressed against each other. Heat can also be provided by emitting ultrasound waves from the sealing device 200. The heat provides that the polymer layer (also referred to herein as the plastic layer) of the packaging material is melted, so that the polymer layer can be used to ensure that the two opposite sides are stuck together and integral after the jaws are removed. In a subsequent step, referred to herein as cutting stage C, the bottom of the tube 104 can be cut to form a package 108. To increase the speed at which the packages are formed, the jaws can be moved together with the tube 104 in the tube feed direction FD during the sealing stage S and cutting stage C.

[0041] To better control the forming process of the package 108, so-called volume forming flaps 204a, 204b may be used. More specifically, they may be used to direct the tube 104 having a circular cross section into the package 108 having a rectangular cross section in a controlled manner.

[0042] The sealing device may comprise two inductors, a first inductor 206a and a second inductor 206b. In the illustrated example, the first inductor 206a is located above the second inductor 206b. After the lateral sealing, a knife 208 may be used to cut the lower part of the tube to form the package 108. In this example, the knife 208 and the first and second inductors 206a, 206b are located within the sealing device, but other arrangements are possible. For example, the knife may be located on the opposite side of the tube, in the counter pressure device, or the cutting step may be performed in a separate device downstream of the sealing device. Alternatively, if ultrasonic sealing technology is used instead of induction heating technology, the sealing device 200 may comprise a transducer adapted to generate ultrasonic waves.

[0043] Figure 3A shows a schematic side view of tube 104 after the longitudinal seals LS and transverse seals TS have been made. Figure 3B shows tube 104, LS and TS, but from a top view.

[0044] As shown, the LS can be provided in a LS region 300 along the tube 104. The TS can be provided in a TS region 302 that extends perpendicular to the LS region 300. A first region 304 can be provided upstream of the TS region 302 with respect to the feed direction FD, and a second region 306 can be provided downstream of the TS region 302 with respect to the feed direction FD. By having the first and second regions 304, 306, a transition region can be provided between the TS and the intermediate portion of the package 108 in which the food product is held. The TS-LS overlap region 308 represents the interface between the TS region 302 and the LS region 300, i.e., where the TS region 302 and the LS region 300 meet. As a result, a three-layer packaging material is provided in this TS-LS region. As described above, after the TS is created, the knife 208 can cut the tube 104. In FIG. 3A, this is shown by the cut line 310. Additionally, as discussed above, LS strips 312 may be provided in LS strip region 314 to protect carton layers and other cellulosic layers in the packaging material.

[0045] Figure 4A shows a first embodiment of the transverse seal system 110 shown in Figure 2, where the sealing device 200 comprises an ultrasonic arrangement 400 and the counter pressure device 202 constitutes an anvil 402. As in Figure 2, the anvil 402 is provided with a recess 403 for receiving the knife 208.

[0046] In this example, the ultrasonic arrangement 400 comprises a sonotrode 404 configured to generate ultrasonic waves, also called ultrasonic vibrations, a first pressure plate 406 arranged downstream of the sonotrode 404 with respect to the feed direction FD, and a second pressure plate 408 arranged upstream of the sonotrode 404. Unlike the sonotrode 404, the first and second pressure plates 406, 408 are static, i.e. non-oscillating.

[0047] By providing the first and second pressure plates 406, 408 next to the sonotrode 404, the ultrasonic vibrations can be directed to a greater extent towards the TS-LS overlap region 308 and the TS region 302 compared to an ultrasonic arrangement consisting of only the sonotrode 404. The advantage of a more defined area of ​​application of ultrasonic vibrations is that the risk of plastic mass build-up in the packaging material is reduced. Furthermore, the effect of being able to better control how the tube 104 is exposed to ultrasonic vibrations is that more reliable predictions can be made of how different anvil profiles, different sonotrode designs, and / or first and second pressure plate profiles will affect the transverse seal. This means that different profiles can be more accurately simulated or virtually modeled for new packaging materials, for example packaging materials where new polymers are used or packaging materials where thinner carton layers are used.

[0048] In addition to focusing ultrasonic vibrations on the TS region 302 of the tube 104, the first and second pressure plates 406, 408 also apply pressure to the tube 104. While the sonotrode 404 applies a TS-LS pressure TS-LS P to the TS-LS overlap region 308, the first pressure plate 406 can apply a first pressure P1 to the first region 304 located upstream of the TS-LS overlap region 308, and the second pressure plate 408 can apply a second pressure P2 to the second region 306 located downstream of the TS-LS overlap region 308. In general, the TS-LS pressure TS-LS P is greater than the first pressure P1 and the second pressure P2. As an effect of the pressure difference, less heat is generated in the TS-LS overlap region 308, i.e. the region where the three layers of packaging material are provided, compared to the first and second regions 304, 306. Alternatively, the anvil 402 can be spring-loaded.

[0049] To provide greater control over the displacement of the molten plastic, the first pressure plate 406 may have a first inclined surface 410 inclined away from the sonotrode 404, and the second pressure plate 408 may have a second inclined surface 412 inclined away from the sonotrode 404.

[0050] Additionally, first and second ridges 414, 416 may be provided on either side of the recess 403 that holds the knife 208 to ensure a good seal on the molten plastic within the food and / or packaging material.

[0051] The width of the recess 403, referred to herein as the recess width Re-W, may be less than one-third the distance between the first and second ridges 414, 416, referred to herein as the ridge distance Ri-D.

[0052] Opposite the recess 403 of the anvil 402 may be a groove 418 of the sonotrode 404. Optionally, a third pressure plate 420 may be provided in this groove 418. Like the first and second pressure plates 406, 408, the third pressure plate 420 may also be static, i.e. non-oscillating, and not active like the sonotrode 404. To provide that the third pressure plate 420 may be static, it may, by way of example, be attached to the first and second pressure plates 406, 408 at the ends (not shown) of the sonotrodes.

[0053] As shown, there may be a gap between the sonotrode 404 and the first and second pressure plates 406, 408. To reduce the risk of food residue or other unwanted particles becoming trapped, the gap may be capable of being cleaned using water.

[0054] Although not shown, the first and / or second pressure plates 406, 408 may include ridges to prevent plastic chunks formed, for example, at the edges of the TS-LS overlap region and / or the edges of the LS strip region from moving away from the TS-LS overlap region and potentially beyond the first and / or second regions 304, 306. Having the ability to prevent the escape of plastic chunks can reduce the risk of producing poor quality packages.

[0055] The ultrasonic waves generated by the sonotrode 404 generate heat, as does the TS-LS pressure TS-LS P created by the sonotrode 404. To compensate for the heat generated as an effect of the lateral seal, the first pressure plate 406 may be provided with a first water-cooled tube 422 and the second pressure plate 408 may be provided with a second water-cooled tube 424. The use of water is beneficial because it does not pose a food safety risk if the first or second water-cooled tubes 422, 424 start to leak for any reason. However, even though water is the option used in many food packaging applications, other cooling media may be applied to reduce the heat generated.

[0056] FIG. 4B shows a second embodiment of the transverse sealing device 110. In contrast to the first embodiment shown in FIG. 4A, in the second embodiment the first and second bevels 410, 412 are provided on the anvil 402 instead of the first and second pressure plates 406, 408. The advantage of providing the bevels on the anvil, as shown in FIG. 4B, is that a more cost-effective sealing device 200 can be realized. That is, it is possible to meet the specific characteristics of the packaging material by adjusting the gradient according to the packaging material, for example by using virtual modeling. By having the same ultrasonic arrangement 400, i.e. the sonotrode 404, the first and second pressure plates 406, 408, but with packaging material-specific anvils for different packaging materials, the sealing device 200 can be adapted to the packaging material in a cost-effective manner.

[0057] The use of packaging materials that include the above-mentioned cellulosic layers creates differences compared to the use of packaging materials that are made of only polymeric layers. One reason for this is that ultrasonic waves propagate differently and to a greater extent in cellulosic layers, such as carton layers, compared to polymeric layers. For this reason, the use of the sealing device 200 shown in Figures 4A and 4B is particularly beneficial for packaging materials that are made of cellulosic layers.

[0058] 4B, by providing the first and second inclined surfaces 410, 412 on the anvil 402, the first and second pressure plates 406, 408 can have surfaces that are horizontal with the surface of the sonotrode 404. This is advantageous in that it keeps manufacturing costs low.

[0059] Figures 5A and 5B show sonotrode 404 in more detail. Figure 5A shows a perspective view of sonotrode 404, and Figure 5B shows a side view of sonotrode 404.

[0060] 6 shows the anvil 402 in more detail. As shown, the anvil 402 may include a TS-LS anvil section 600 with a TS-LS anvil profile 602 arranged to fill the TS-LS overlap region 308 of the tube 104, and a TS anvil profile 606 on the TS anvil section 604 arranged to fill the TS region 302 of the tube 104. The width of the TS-LS anvil section 600 may be larger than the TS-LS overlap region 308, which allows for less dependency on tube rotation, i.e., improved handling of deviations in the LS placement method in the transverse seal system 110. Having the first and second pressure plates 406, 408 provides adequate sealing for both two- and three-ply packaging materials.

[0061] 7 is a flow chart showing an example method 700 for transversely sealing a tube 104 of packaging material. In a first step 702, the tube 104 of packaging material can be fed in a feed direction FD. In a second step 704, ultrasonic waves can be generated using a sonotrode 404 included in an ultrasonic arrangement 400 such that an inner layer of the packaging material in the transverse seal area 302 is at least partially melted. In a third step 706, the ultrasonic arrangement 400 is moved in a first sealing direction SD-1 and the anvil 402 is moved in a second sealing direction SD-2 to compress the tube 104 in the transverse seal area 302.

[0062] Optionally, in a fourth step 708, stress is relieved from the first region 304 by a first slope 410 sloping away from the sonotrode 404, and / or in a fifth step 710, stress is relieved from the second region 306 by a second slope 412 sloping away from the sonotrode 404.

[0063] Optionally, in a sixth step 712, the plastic mass formed at the edge of the TS-LS overlap region 308 and / or the edge of the LS-strip region 312 can be blocked by at least one ridge provided on the first and / or second pressure plates 406, 408.

[0064] From the foregoing description, various embodiments of the present invention have been described and illustrated, however the invention is not limited thereto and may be embodied in other ways within the scope of the subject matter defined in the following claims.

Claims

1. A lateral sealing (TS) system (110) for a packaging machine (100), wherein the lateral sealing system (110) is The ultrasonic placement portion (400) is positioned so as to face the outer surface of the packaging material tube (104) from a first sealing direction (SD-1), the first sealing direction (SD-1) being perpendicular to the supply direction (FD) of the tube (104), and the tube (104) includes a longitudinal seal (LS) region (300) where at least two layers of the packaging material overlap. An anvil (402) is positioned so as to face the outer surface from the second sealing direction (SD-2), and the second sealing direction (SD-2) is opposite to the first sealing direction (SD-1). Equipped with, The ultrasonic placement section (400) is A sonotrode (404) that applies ultrasonic vibrations so as to melt at least partially the inner layer of the packaging material, Adjacent to the sonotrode (402), positioned upstream of the tube (104) in the supply direction (FD), is a non-vibrating first pressure plate (406), Adjacent to the sonotrode (404), positioned downstream of the tube (104) in the supply direction (FD), is a second non-vibrating pressure plate (408), Equipped with, The sonotrode (404) is arranged to provide TS-LS overlap pressure (TS-LS P) to the TS-LS overlap region (308), the first pressure plate (406) is arranged to provide a first pressure (P1) to a first region (304) located upstream of the TS-LS overlap region (308) in the supply direction (FD), and the second pressure plate (408) is arranged to supply a second pressure (P2) to a second region (306) located downstream of the TS-LS overlap region (308) in the supply direction (FD). Lateral sealing system.

2. The TS-LS overlap pressure (TS-LS P) is greater than the first pressure (P1) and the second pressure (P2). The lateral sealing system according to claim 1.

3. The first pressure plate (406) is provided with a first inclined surface (410) that is inclined away from the sonotrode (404), and / or the second pressure plate (408) is provided with a second inclined surface (412) that is inclined away from the sonotrode (404). The lateral sealing system according to claim 1.

4. The anvil (402) comprises a first slope (410) and / or a second slope (412) that slopes away from the sonotorode (404), The lateral sealing system according to claim 1.

5. The first pressure plate (406) and the second pressure plate (408) extend along the entire width of the sonotrode (404). The lateral sealing system according to claim 1.

6. The anvil comprises a TS-LS anvil profile (602) in a TS-LS anvil section (600) arranged to fit the TS-LS overlap region (308) of the tube (104), and a TS anvil profile (606) in a TS anvil section (604) arranged to fit the TS region (302) of the tube (104). The lateral sealing system according to claim 1.

7. The sonotrode (404) comprises a TS-LS sonotrode profile in a TS-LS sonotrode section arranged to fit the TS-LS overlap region (308) of the tube (104), and a TS sonotrode profile in a TS sonotrode section arranged to fit the TS region (302) of the tube (104). The lateral sealing system according to claim 1.

8. The first pressure plate (406) and / or the second pressure plate (408) are provided with at least one raised portion for blocking plastic lumps formed on the edges of the TS-LS overlap region (308) and / or the edges of the LS strip region (312). The lateral sealing system according to claim 1.

9. The first pressure plate (406) and / or the second pressure plate (408) or the anvil (402) is spring-loaded. The lateral sealing system according to claim 1.

10. The sonotrode (404) further comprises a third pressure plate (420) positioned in a groove (418). The lateral sealing system according to claim 1.

11. The packaging material comprises at least one cellulose-based layer such as a carton layer and an inner polymer layer, and does not contain aluminum. The lateral sealing system according to claim 1.

12. The receiving container for the packaging material, A food filling pipe (106) is positioned to fill a tube (104) with food, and The lateral sealing system (110) according to claim 1, A packaging machine (100) equipped with the following.

13. A method (700) for sealing a tube (104) of packaging material in the lateral direction, wherein the method is The tube (104) of the packaging material is supplied in the supply direction (FD) (702), Ultrasound is generated (704) using a sonotrode (404) contained in the ultrasonic placement section (400) so that the inner layer of the packaging material in the lateral sealing region (302) is at least partially melted. The method comprises moving the ultrasonic placement section (400) in a first sealing direction (SD-1) and moving the anvil (402) in a second sealing direction (SD-2) to compress the tube (104) in the lateral sealing region (302) (706), wherein the second sealing direction (SD-2) is opposite to the first sealing direction (SD-1). The ultrasonic placement section (400) is Sonotoro Road (404) and, Adjacent to the sonotrode (402), positioned upstream of the tube (104) in the supply direction (FD), is a non-vibrating first pressure plate (406), Adjacent to the sonotrode (404), positioned downstream of the tube (104) in the supply direction (FD), is a second non-vibrating pressure plate (408), Equipped with, The sonotrode (404) is arranged to provide TS-LS overlap pressure (TS-LS P) to the TS-LS overlap region (308), the first pressure plate (406) is arranged to provide a first pressure (P1) to a first region (304) located upstream of the TS-LS overlap region (308) in the supply direction (FD), and the second pressure plate (408) is arranged to supply a second pressure (P2) to a second region (306) located downstream of the TS-LS overlap region (308) in the supply direction (FD). method.

14. The stress is released from the first region (304) by the first slope (410) which slopes away from the sonotrode (404) (708), and / or The stress is released from the second region (306) by the second slope (412) which is inclined away from the sonotrode (408) (710), The method according to claim 13, further comprising:

15. The first pressure plate (406) and / or the second pressure plate (408) are provided with at least one raised portion to block (712) the plastic mass formed on the edge of the TS-LS overlap region (308) and / or the edge of the LS strip region (312), The method according to claim 14, further comprising:

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