JPS62246717A - Super-sonic sealing apparatus for sealing bottom of tubular container - Google Patents

Abstract

PURPOSE:To secure the transmission of super-sonic oscillation to a welding sheet and to simplify an apparatus for the carry-in or the carry-out of a welding article, by making a plane where the horn and the anvil of super-sonic oscillator contact the welding sheet into a specific shape. CONSTITUTION:The side faces of convex parts 5, 5 provided at planes 3, 3 where the horn 1 and the anvil 2 of a super-sonic oscillation contact a welding sheet are inclined at theta degrees and becomes inclined slopes 6. By making the convex parts 5, 5 into trapezoid forms by providing such inclined slopes 6, when multi-layered sheets are welded each other, the convex parts 5 bite into the above-mentioned sheet and transmit super-sonic oscillation certainly deep into the multi-layered sheets, whereby sufficient melting and firm welding can be done. Furthermore as it is possible to transmit super-sonic oscillation certainly to the welding plane, an apparatus to support firmly under interposing used formerly becomes unnecessary, and it can be done only with a conveyer to carry-in or carry-out a welding article 17.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an ultrasonic sealing device for sealing the bottom of a tube container. [Prior art and its problems] Ultrasonic sealing devices that weld a pair of sheet-like objects together using ultrasonic vibrations include: ■ So-called longitudinal vibration type devices that apply ultrasonic vibrations in a direction perpendicular to the welding surface; ■The so-called transverse vibration type, which applies ultrasonic vibration in a direction parallel to the welding surface.
No. (Japanese Unexamined Patent Publication No. 58-33424) and patent application No. 5'187
No. 765 (Japanese Unexamined Patent Publication No. 58-205723) proposed,
There are three types of diagonal vibration types that apply ultrasonic vibration in an oblique direction to the welding surface. Looking at the characteristics of each of these three types, the longitudinal vibration type applies vibration in a direction perpendicular to the welding surface, so a so-called lateral slip phenomenon occurs between the horn and anvil and the sheet material to be welded. However, since vibration is applied in a direction perpendicular to the welding surface, when welding the bottom of a tube container, even if the filling inside the container is attached to the welding surface, the vibration will cause the filling to be moved out of the welding surface. Therefore, it is not suitable for welding the bottom of a tube container containing cosmetics or the like. On the other hand, the transverse vibration type and diagonal vibration type have the ability to scatter the filler attached to the welding surface to the outside of the welding surface by vibration, so they have been traditionally used for sealing the bottom of tube containers. It is used. However, with the lateral vibration type, since vibration is applied in a direction parallel to the welding surface, a lateral slip phenomenon occurs between the horn and anvil and the sheet material held between them, and the vibration effectively affects the welding surface. The horn may generate heat due to poor transmission, insufficient frictional heat due to vibration may result in poor welding, unpleasant high-pitched noise may occur due to sideways slipping, or contact with the horn or anvil may occur. There is a problem that hangnails or scrapes may occur on the surface of the sheet-like material. Therefore, an uneven pattern as shown in Fig. 12 is engraved on the contact surface of the horn and the anvil with the sheet-like material, but very good results have not been obtained with the 4 uniform uneven patterns shown in Fig. 12. do not have. In addition, in the diagonal vibration type, the vibration is distributed in the vertical and horizontal directions, so it has the advantages of both the vertical vibration type and the horizontal vibration type.
It has the ability to blow away foreign matter adhering to the welding surface laterally, and also suppresses the side-slip phenomenon to some extent, making it possible to weld more efficiently than the lateral vibration type. Therefore, it shows good results in welding multilayer sheets together, which is not so good with the transverse vibration type. However, the fact remains that a side-slip phenomenon occurs, and this side-slip phenomenon cannot be eliminated even by carving a concave-convex pattern on the contact surface as shown in Fig. 12. Efficient welding is desired. By the way, in the conventional ultrasonic sealing device for sealing the bottom of a tube, before the bottom of the tube container is held between the horn and the anvil, a holding device 20 called a jaw as shown in FIGS. 15 and 16 is used. After that, the bottom of the tube container 17 is held between the horn 1 and the anvil 2 and welded. To explain this clamping device 20, a sliding body 22 is slidably provided in a frame member 21,
The slide body 22 is biased in the clamping direction by a spring 23 so that the frame member 21 and the slide body 22 clamp the bottom portion 17 of the tube. A pair of guide plates 24 are vertically disposed diagonally between the lower part of the frame member 21 and the lower part of the sliding body 22, and guide the circular tube container 17 between the frame member 21 and the sliding body 22 so as to be flat. It looks like this. The reason why such a device is necessary is that, as mentioned above, conventional sealing devices cannot reliably weld, so the clamping device 20 is used to clamp and assist in ensuring welding. In addition, by holding the bottom of the tube container 17, the molten resin generated on the welding surface during welding by ultrasonic vibration is
This is to prevent it from flowing into the interior. However, the need for such a clamping device creates new problems. The first problem is that molten resin accumulates between the part held between the horn and the anvil and the part that is held by the clamping device. A bulge 25 occurs, resulting in an extremely poor appearance. The second problem is that the presence of such a clamping device complicates the mass production line. That is, to explain a conventional sealing device having such a clamping device, as shown in FIG. turntable 32 and this turntable 32
It is necessary to provide a carry-out conveyor 33 that receives and carries out the sealed tube container 17 after sealing with the horn l and anvil 2 installed on one side, and the carry-in conveyor 31 and the carry-out conveyor 33 are sandwiched between each other. In order to transfer the tube container 17 to and from the device 20, a container holder 34 which also serves as a lifting device is required. If the clamping device 20 is eliminated, the container holder 34 and the turntable 32, which also serve as lifting devices, become unnecessary, and the carry-in conveyor 31 and the carry-out conveyor 33 can be formed by a single conveyor, making it possible to form an extremely simple mass production line. . By the way, as a premise for omitting such a clamping device,
It is necessary to improve the uneven pattern engraved on the contact surface of the horn and anvil to make the welding reliable and strong. Care must be taken to ensure that the contact surface parallel to the surface is left as wide as possible on the horn or anvil, and that the uneven patterns formed on the horn and anvil are reliably bitten to eliminate side slip. The case where the contact surface parallel to the welding surface is maximum is when no uneven pattern is provided, but in this case, the degree of side slip is also maximum as described above. On the other hand, the case where the indentation of the uneven pattern is maximized is the case where the tips of the protrusions are made sharp.
In this case, there is no contact surface parallel to the welding surface, so
Ultrasonic vibrations are less likely to be transmitted to the welding surface and less likely to generate frictional heat. Considering the uniform uneven pattern 8 shown in FIG. 12 from this point of view, it can be seen that the diagonal intersecting grooves 4 form a convex portion 5 having a rectangular planar shape. Since the side surfaces are vertical surfaces 41, it is difficult for the convex portions 5 to bite into the sheet-like object, making it impossible to reliably suppress side slipping. In addition, as another conventional example, Utility Model Application Publication No. 60-201928

[Fig. 13(a), (b), and (c)] is a superstructure in which a plurality of uneven lines 42 are cut along the longitudinal direction of the contact surface at a constant depth and protruding height. A horn for sonic sealing is described, and specifically, it is described that the uneven stripe 42 is a continuous uneven surface having no corners in a sine wave shape in the cross section of the contact surface in the transverse direction. However, it is clear from Fig. 13(a) that the ultrasonic sealing device described in this publication is of the longitudinal vibration type (the vibration direction of the ultrasonic wave is the axial direction of the horn; (Since the contact surface is provided at the tip, it is understood that vibration is applied in a direction perpendicular to the welding surface of the sheet).Therefore, the uneven pattern to prevent side slipping is essentially unnecessary. Nevertheless, the purpose of providing the uneven stripes 42 is to hold the resin melted by ultrasonic vibration in a flowing position at the sealing portion and to improve the welding ability. Even if this structure is used in a transverse vibration type or diagonal vibration type device, since the cross section of the uneven stripes 42 is sinusoidal, there is no contact surface parallel to the welding surface, and the frictional heat is not sufficiently absorbed. In addition to not occurring, the uneven streaks 42 that have dug in have little effect on suppressing lateral slip. Against this background, the inventors of the present invention etched various uneven patterns on the contact surfaces of horns and anvils and repeated experiments. In order to ensure that the convex part bites into the sheet-like object, it is necessary to maximize the contact surface parallel to the welding surface, that is, without providing the convex part [Fig. 11(a)], and to In other words, the tip of the convex part is sharpened.

Intermediate state with [Figure 11(b)]

[Fig. 11(C)] was found to be the most effective method. The present invention was made against this background, and an object of the present invention is to improve the uneven pattern to be carved on the contact surface of the horn and anvil that clamp the tube container in an ultrasonic sealing device for sealing the bottom of the tube container. As a result, ultrasonic vibrations are efficiently transmitted to the sheet-like object, and welding is performed reliably and firmly, thereby omitting a clamping device and thereby simplifying the entire ultrasonic sealing device. This is a technical issue. [Means for Solving the Problems] In order to solve the above-mentioned technical problem, the present invention includes a horn 1 and an anvil 2 that sandwich the bottom of a tube container made of thermoplastic resin, and generate ultrasonic vibrations. In an ultrasonic sealing device that welds the bottom of the tube container using frictional heat, the following technical measures were taken. Note that the ultrasonic sealing device in this case is limited to a transverse vibration type or an oblique vibration type, as a logical premise for the purpose of the present invention. The gist of the present invention is to form grooves 4 in each contact surface 3 of the horn l and anvil 2 that contact the bottom of the tube container 17, thereby forming a plurality of convex portions 5 whose upper surfaces are flat. The side surface of the convex part 5 is made into an inclined surface 6 so that the cross section of the part 5 is trapezoidal, and a tube container is placed between the horn l and the anvil 2 when the horn l and the anvil 2 are opened without providing a clamping device. This is due to the installation of a conveyor that directly positions the bottom of No. 17. First, the uneven pattern to be carved on each contact surface 3 of the horn 1 and anvil 2 will be described. The inclination angle θ of the inclined surface 6 of the convex portion 5 formed by the groove 4 needs to be changed somewhat depending on the material of the tube container 17 to be welded, but it is generally 5 to 45 degrees, preferably 10 to 30 degrees. The degree is good. Further, the grooves 4 for forming the plurality of convex portions 5 may be straight grooves 4 and then carved so as to intersect with each other, or grooves 4 may be carved so as to form a curved pattern that is not straight. In the former case, as shown in FIGS. 7 and 8, the rectangular or triangular convex portions 5 are formed in a continuous pattern,
In the latter case, a zigzag pattern or a wave pattern is formed when viewed from a plane, or as shown in FIG. An example of this is to form a pattern in which the grooves 4 and the protrusions 5 are repeated (Fig. 3), or a pattern in which the circular protrusions 5 are repeated (Fig. 1O). Taking into account the need to generate more heat, shorten the sealing time, and minimize the pressure applied by the horn 1 and anvil 2, it is possible to Distance Q to one end of 5 (pattern pitch)
is 0.5~'1. O shoulder x, preferably 0.8~l,
A size of 61jl is good. Note that the shape and size of the protrusion 5 on the horn I side may be different from the shape and size of the protrusion 5 on the anvil 2 side. Furthermore, in order to obtain sufficient frictional heat, it is necessary to leave a certain amount of flat surface parallel to the welding surface. The ratio is 30 near 0 to 64:3
6, preferably around 40:60. Moreover, if the groove 4 for forming the convex part 5 is too deep, the convex part 5 will bite too deeply into the sheet of the tube container 17, such as when welding a tube container 17 made of thermoplastic resin, and the thickness of the welded part will increase. There is a risk that the seal will become thin and be torn off, and if the volume of the groove 4 becomes too large, a large amount of molten resin will enter therein, and if it solidifies, the appearance of the sealed portion will deteriorate. On the other hand, if the groove 4 is too shallow, the amount of bite of the convex portion 5 will be small, making it insufficient to suppress the side-slip phenomenon, and the efficiency of generating frictional heat at the welding surface will deteriorate. Therefore, the depth of the groove 4 is 35 to 65% of the thickness of one sheet of the tube container 17 to be welded, preferably 4
0 to 60% is preferred. By the way, the depths of the grooves 4 on the horn i side and the grooves 4 on the anvil 2 side do not need to be the same, and one may be deeper than the other. By the way, the tube containers to be welded by the ultrasonic sealing device of the present invention include a single-layer sheet of thermoplastic resin, a multi-layer sheet of thermoplastic resin, a thermoplastic resin layer and a sheet layer of other material other than synthetic resin, such as paper or aluminum. It is molded from a multilayer sheet made of Regarding the case where a multilayer sheet is used for a tube container, the inner layer is made of high-density polyethylene (HDPE).
) and the outer layer is low-density polyethylene (LDPE), or a multi-layer tube with a gas barrier resin layer such as EVAL or nylon between high-density polyethylene and low-density polyethylene, and a sheet layer made of different materials. A multilayer sheet having a laminate layer is a multilayer tube having an aluminum laminate layer as an intermediate layer. Next, the entire apparatus of the present invention will be explained. First, let's talk about the case of an oblique vibration type ultrasonic sealing device.As shown in FIG. The oscillator 13, the amplifier 14, and the horn 1 are arranged and attached on the same axis, and ultrasonic vibrations are oscillated in the direction of this axis. The horn 1 has a pair of contact surfaces 3 on both sides of the tip, and each contact surface 3 is set so that the angle ψ with respect to the axis of the horn 1 is 5 to 40 degrees. This angle is preferably around 20 degrees. Then, the horn 1 and the anvil 2 are installed so that they can move forward and backward so that the space between the horn 1 and the anvil 2 can be opened and closed, or the horn 1 side is fixed and the anvil 2 side is set up so that the anvil 2 side can move forward and backward,
Alternatively, it is conceivable to fix the anvil 2 side and make the horn 1 side move forward and backward, but it is easiest to make the anvil 2 move forward and backward. The driving means for this purpose is preferably a hydraulic cylinder or the like. Moreover, when the horn l is fixed, it is fixed so that the contact surface 3 of the horn l stands upright. The anvil 2 can be set so that the contact surface 3 of the tip of the horn l and the contact surface 3 of the anvil 2 are larger than the diameter of the maximum tube container 17 in the retracted position. However, it is preferable for this interval to be narrower than the diameter of the tube container 17 for positioning during welding, and in reality it is 5 to 1
About 5ii is good. If this distance is greater than or equal to the diameter of the tube container 17, the tube container 17 can be directly positioned between the horn 1 and the anvil 2 and held and welded therebetween. If the diameter is less than the diameter of the tube container 17, as shown in FIG. 4(a), a guide 18 is required between the horn l and the anvil 2 to guide the tube container 17 from the side. 18 has a guide surface 1 formed of a pair of tapered surfaces or convex arc surfaces in order to flatten the tube container 17.
Set up 9/19. Then, the tube container 17 is carried in between the horn L and the anvil 2 from the guide 18 side, the tube container 17 is positioned between the horn L and the anvil 2, and the tube container 17 is temporarily stopped, and the tube container 17 is carried out after welding. A conveyor 15 is installed below pawn l and anvil 2. This conveyor 15
Since it is sufficient to carry in and carry out the tube container 17 from one side of the horn 1 and the anvil 2 to the other side, it is sufficient to install the tube container 17 in a straight line. Further, holders 16 for holding the tube containers 15 upside down are provided on the conveyor 15 at regular intervals. Next, in the transverse vibration type ultrasonic sealing device, as shown in FIGS. 5 and 6, the axis connecting the ultrasonic oscillator 13, amplifier 14, and horn l is fixed upright, and A pair of parallel contact surfaces 3 are provided on both sides of the tip of the horn 1, and other points are the same as the oblique vibration type ultrasonic sealing device. In this case, ultrasonic vibrations vibrating in the axial direction of the horn 1 are applied in a direction parallel to the welding surface of the tube container 17 via the contact surface 3. [Function] According to the present invention, since the side surface of the convex portion 5 provided on the contact surface 3 of the horn 1 and the anvil 2 is formed into an inclined surface 6, it is easy to bite into a sheet-like object. In particular, when welding multilayer sheets together, the protrusions 5 tend to dig into each other, so by appropriately selecting the height of the protrusions 5, that is, the depth of the grooves 4, welding the multilayer sheets together, as shown in FIG. 4(b), Among each layer of the sheet, the convex portion 5 can be made to bite into the inner layer on the welding surface side, and ultrasonic vibration can be reliably transmitted to the welding surface to efficiently generate frictional heat. Can be done. In this respect, if the convex portion 5 only bites into the outer layer,
Since the ultrasonic vibrations are not directly transmitted to the inner layer but are transmitted through the outer layer, they are attenuated when being transmitted from the outer layer to the inner layer, and therefore, sufficient frictional heat is not generated. In particular, when welding the bottom of a multilayer tube that has polyethylene layers as the inner and outer layers and an EVAL layer as the middle layer, the polyethylene layer and the EVAL layer are not bonded together due to the nature of the resin, so the convex part extends to the inner polyethylene layer. Welding was difficult with conventional means in which the protrusions 5 do not cut into the inner layer, but according to the present invention, the protrusions 5 cut into the inner layer, so welding can be performed satisfactorily. As a result, the holding device that was conventionally required is not required, the structure of the device is simplified, and the entire process is simplified. Further, by forming the inclined surface 6, the cross section of the groove 4 itself also becomes trapezoidal, and the sheet-like material that has bitten into the groove 4 is likely to be peeled off from the pattern surface after welding. When the grooves 4 for forming the convex portions 5 are not straight but have a curved pattern, the resin melted by ultrasonic vibration is evenly distributed over the welding surface along the grooves 4. Therefore, there is no unevenness in the welding of the pair of sheet-like materials, and the welding can be performed reliably and firmly. This effect is most remarkable when the planar shape of the convex portion 5 formed by the curved pattern of grooves 4 is a honeycomb. In this regard, if the groove 4 is straight, the molten resin will flow in one direction only, and there will be parts with too little molten resin and parts with too much molten resin on the welding surface, resulting in uneven welding, and in the worst case, parts will not be welded. There is a risk. Furthermore, in order to obtain sufficient frictional heat, it is necessary to leave some flat surface parallel to the welding surface, but in the case of the present invention, the upper surface of the convex portion 5 is left as a flat surface, so this problem is solved. None. In addition, in the case of an oblique vibration type ultrasonic sealing device, since ultrasonic vibration is applied from an oblique direction, even if the filling in the tube container is attached to the welding surface, the filling can be scattered outside the welding surface. As described above, if the convex portion 5 whose side surface is an inclined surface 6 is provided on the contact surface 3 of the horn 1 or the anvil 2 as in the present invention, the filling material can be scattered outside the welding surface. You can do it more effectively. Therefore,
Welding can be performed even when the cosmetic is attached to the welding surface, and furthermore, welding can be performed even when the tube container is filled with cosmetic solution and sealed with the cosmetic solution still attached to the welding surface. [Examples/Comparative Examples] Examples of the present invention will be described below while comparing them with comparative examples. Then, the bottoms of tube containers 17 made of various materials were sealed using the oblique vibration type and transverse vibration type ultrasonic sealing devices, and the seal strength was measured. The results are shown in Table 1. The uneven patterns formed on the contact surfaces 3 of the horn 1 and the anvil 2 are the honeycomb-shaped pattern shown in FIG.
The pattern shown in the figure is a conventional rectangular pattern. The pattern pitch ρ of the honeycomb-shaped uneven pattern used was 1.
1xm, the ratio of the groove 4 to the plane on the convex portion is 41=59, and the depth of the groove 4 is 0.211I. (Hereafter, blank space) Table 1 (Sealability) ◎: Very good O: Good ×: LDPE with problems
...Low density polyethylene MDPE...
Medium density polyethylene HDPE...High density polyethylene PP...Polypropylene AL...Fulminilam Ultrasonic frequency: 20 & Hz Output 1.8H <thickness of each layer> LDPE single layer -360 (μm) MDPF: single layer ・・・400 (μtoge LDPE/nylon/
PP...170/60/17
G (μ Pass LDPE/HDPE...150/30
0 (μm) LDPE/EVAL/MDPE...
・170/60/170 (μs LDPE/LDPE/A
L/PE/LDPE...250/90/12/12/
80 (μm) LDPE/AL/LDPE/Paper DPE
...200/12/90/20/80 (μm) LDP
E/LDPE...3807380 (μm) 1st
As is clear from the table, the honeycomb-shaped convex portion 5 is connected to the contact surface 3.
The seal provided in the sealing device provides better sealing than the conventional sealing device, and especially when combined with an oblique vibration type ultrasonic sealing device, very good results can be obtained. Since the side surface of the convex portion 5 is an inclined surface 6, it has good biting, and the unpleasant friction noise generated during sealing is small.
Further, the tube was easily separated from the pattern surface after sealing. Since the combination of the oblique vibration type ultrasonic sealing device and the honeycomb-shaped convex portion 5 is good as described above, experimental data for this combination is shown in Table 2. The seal strength was determined using a tension compression tester at a pressure speed of 100J! The measurement was performed under jI/min and pressure surface condition: φ60xi. As is clear from Table 2, the combination of the oblique vibration type ultrasonic sealing device and the honeycomb convex portion 5 has a short welding time and high sealing strength. Thus, in the present invention, welding could be performed reliably and firmly even without a clamping device. [Effects of the Invention] According to the present invention, the side surface of the convex portion provided on the contact surface of the horn and the anvil is made into an inclined surface, so that it can easily bite into a sheet-like object, and therefore, the side-slip phenomenon can be suppressed as much as possible. Ultrasonic vibrations are reliably transmitted to the welding surface, efficiently generating frictional heat, and welding is made reliable and strong. This eliminates the need for a holding device that was previously required, and as a result, there is no gap between the horn and anvil. Transporting tube containers
It can be a simple device that only includes a conveyor for carrying out, and the holder itself for holding the tube container does not need to have the function of a lifting device, so the cost of the entire device can be reduced. Moreover, it is possible to obtain the effect that the installation space can be small.

[Brief explanation of drawings]

Fig. 1 is a front view of an oblique vibration type ultrasonic sealing device showing one embodiment of the present invention, Fig. 2 is a front view of its horn and anvil portion, and Figs. 3 (a) and (b) are according to the present invention. FIG. 4(a) is a plan view and cross-sectional view showing an example of an uneven pattern; FIG. 4(a) is a process diagram showing the process of sealing the bottom of a tube container; FIG. Figure 5 is a front view of the transverse vibration type ultrasonic sealing device, Figure 6 is a front view of its horn and anvil portion, Figures 7 to 10 are plan views showing other examples of uneven patterns, and Figure 11 is a front view of the transverse vibration type ultrasonic sealing device. 12(a) and 12(b) are plan views and sectional views showing the conventional uneven pattern, and FIG. 13(a) (b) (
c) is a diagram showing a horn and its contact surface portion showing another conventional example, FIG. 14 is a front view showing a conventional oblique vibration type ultrasonic sealing device, and FIGS. 15 and 16 are views showing the jaw portion thereof. The cross-sectional view and perspective view shown in FIGS. 17(a) and 17(b) are diagrams showing a sealing failure caused by a conventional device using a clamping device. 1...Pawn, 2...Anvil, 3
...Contact surface, 4...Groove, 5...Protrusion, 6...Slanted surface, 15...Conveyor. Figure 1 Figure 3 (a) (b) Figure 15 Figure 16 Figure 24 to 9 171 (a) (b)

Claims (11)

[Claims] (1) An ultrasonic sealing device in which the bottom of a tube container made of thermoplastic resin is held between a horn and an anvil, and the bottom of the tube container is welded using frictional heat generated by ultrasonic vibration. A plurality of convex portions each having a flat top surface are formed by forming grooves on each contact surface of the horn and anvil that abut the bottom portion, and the side surfaces of the convex portions are sloped surfaces so that the cross section of the convex portions is trapezoidal, An ultrasonic sealing device for sealing the bottom of a tube container, characterized in that a conveyor is installed to position the bottom of the tube container between the horn and anvil when the horn and anvil are in an open state. (2) An ultrasonic seal for sealing the bottom of a tube container according to claim 1, characterized in that a guide is provided between each contact surface of the horn and the anvil to flatten and guide the bottom of the tube container. Device. (3) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 1, wherein the grooves for forming the plurality of convex portions form a bent pattern. (4) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 1, wherein the vibration direction of the ultrasonic wave is oblique to the welding surface of the bottom of the tube container. (5) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 1, wherein the vibration direction of the ultrasonic wave is parallel to the welding surface of the bottom of the tube container. (6) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 1, wherein the tube container is formed of a single layer sheet of thermoplastic resin. (7) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 1, wherein the tube container is formed of a multilayer sheet of thermoplastic resin. (8) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 3, wherein the planar shape of each convex portion formed by the groove is a honeycomb shape. (9) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 3, wherein each convex portion formed by the groove has an octagonal planar shape. (10) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 3, wherein each convex portion formed by the groove has a circular planar shape. (11) The ultrasonic sealing device for sealing the bottom of a tube container according to claim 7, wherein the multilayer sheet includes a sheet layer made of a thermoplastic resin and a different material.