JPS6151330A - Method of assembling pressure-resistant vessel made of paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The disclosed technology belongs to the technical field of assembling body materials for carbonated beverages such as beer and cider.

Therefore, when joining the skirt portion of the lid material to the body material of a pressure-resistant container for storing carbonated drinks such as beer and cider, the present invention irradiates ultrasonic waves from the outside at the end of the body material. The invention relates to an assembly method having a step of welding and joining the body material, and in particular, when performing the ultrasonic irradiation, the end face of the end joint part of the body material, or the side face or both sides thereof. A propagation material such as a specified metal material is brought into contact with the joint so that the ultrasonic pressure wave is released from the joint to prevent damage to the end of the lid material, a part of the shoulder, or the end of the body material. This invention relates to a method for assembling a pressure-resistant paper container.

<Prior Art> As is well known, containers for storing carbonated drinks such as beer and cider are susceptible to permeation of carbon dioxide gas due to the internal pressure of carbon dioxide gas. Glass bottles must have gas barrier properties, and for this reason, glass bottles that basically meet these requirements and are reasonably priced have been widely used. Although there are economic and resource saving benefits by being able to collect and use repeatedly,
On the other hand, it has the disadvantage of being heavy and requiring extra transportation costs, and on top of that, when it is exposed to high temperatures in the summer and stored, improper handling can lead to accidents such as unexpected bursting. Furthermore, the work is extremely complicated as it requires secondary processes such as cleaning and inspection of empty bottles due to the use of recycled materials, and treatment of cleaning wastewater, and the facilities required for this are extremely complicated. It was complicated and could not necessarily be said to be an economically superior container.

Therefore, recently, in the distribution field that handles carbonated drinks, technology has been developed for glass bottles as well, such as wrapping plastic shrink labels around lightweight glass bottles to reduce the risk of bursting and making them into disposable containers. Disposable lightweight glass bottles are being used with the aim of making them economically viable by pulverizing them after use and effectively recycling them into glass products, but there are many difficulties in establishing a new collection system. However, there are certain drawbacks, such as the undesirable situation where used lightweight bottles are scattered on roads and in parks and recreational areas, and as they are extremely dangerous, they are attracting attention as a social issue of the times.

Metal cans, such as so-called aluminum cans, which have appeared as an alternative to this, are not only relatively easy to manufacture as containers, but are also lightweight, pressure-resistant, and have a so-called gas barrier that prevents gas permeation. It has extremely excellent physical properties such as elasticity, low cost due to mass production, stable demand forecast due to ease of use, and has the potential for mass distribution, so it has recently been sold automatically. However, as with the glass bottles mentioned above, the problem of empty can pollution has recently become impossible to ignore, and in some cases, the industry has introduced a deposit system under the guidance of local governments to collect and recycle resources. Although there has been a shift towards a more comprehensive approach, the current situation is that the situation as a whole remains unresolved and left unchecked.

In addition, there are no domestic resources for aluminum, the raw material for aluminum cans, and the problem is that they are completely dependent on imports from overseas.Furthermore, the electricity required for scouring is extremely large, making the electricity cost relatively low. In Japan, where prices are high, using such expensive materials in a disposable manner is not appropriate to the times and will sooner or later become the subject of criticism.

Polyester containers, commonly known as PE'T bottles, that have recently appeared here are lightweight and safe when used, are flammable when disposed of, and offer flexibility in container design in the distribution department.
Although it is attracting attention due to its excellent design, like the metal cans mentioned above, it causes environmental pollution due to mass disposal after use, or is difficult to crush in general incinerators. However, it has the disadvantage that it cannot be easily adapted to incineration work due to its bulkiness and difficulty in handling, and in practical terms, it has problems that make it difficult to adopt it in large quantities and over a wide area.

In fact, under the guidance of administrative authorities and self-regulation by related industries, there is a condition that prohibits the sale of containers with sizes under 11, except for certain uses, which does not seem to be effective.

By the way, paper as a membrane material is a rare resource, and the potential of related technology is historically high, lightweight, and
It is inexpensive, it is extremely easy to incinerate after use, it has excellent crushability, it is easy to handle, it requires almost no exhaust gas treatment, and depending on the treatment, it can be reused as waste paper. A recycling system has been established since then.

In addition, paper processing technology is highly developed, supported by the expansion of excellent educational policies and the dramatic rise of industries such as information, printing, and office work, and furthermore, there is a large amount of potential development and research accumulated. has the favorable condition of being extremely large.

Therefore, 1. In the field of static pressure containers such as milk containers, they were seen as an alternative container from an early stage, and the basic conditions such as waterproofness and sealability were technically solved in the early stages of development, and as is well known, they were not put into practical use. It has come to be widely used.

Therefore, there has been a strong demand for a switch to paper containers even in the field of pressure-resistant containers for carbonated beverages such as beer and cider.

Regarding paper containers for storing beverages at near normal pressure, recent practical developments have been published as publicly known techniques in some areas related to printing, which are excellent in paper material processing technology.

However, the reason why the development of paper-made pressure-resistant containers for carbonated beverages has been delayed is not only due to economic issues, but also because of the three-dimensionally curved structure of the pressure-resistant containers, which requires many challenges to be overcome. This is because there are latent technical obstacles; for example, the design conditions for pressure-resistant specifications required for pressure-resistant containers for carbonated beverages such as beer and Zyder are quite high; Beer containers at room temperature 2~
2.5Kg/Cl12 gauge pressure, 4-5Ka at 50℃
/cm2 gauge pressure, and the container of Saigu has an internal pressure of 3 to 3.5 K (] / cm2 gauge pressure at room temperature, and 6-7 Kg/cm2 gauge pressure at 50°C, therefore, the two In order to have pressure resistance, it is necessary to make the shape have a circular curved part to make it rough against internal pressure, but since flat plate shapes are common for glass and aluminum, It has extremely disadvantageous conditions in terms of processing into three-dimensional shapes.

In addition, flat paper materials have poor workability such as bending, and the joint between the body material and lid material, which forms the basic simple structure of a three-dimensional container, is sealed by wrapping it like a metal can. It is extremely difficult to do so, and the fourth reason is that the paper itself has poor pressure resistance and gas barrier properties. In addition, as shown in (e) above, it is also required to ensure bonding weldability and sufficient bonding strength when bonding the lid material and the body material, which have a circularly curved surface. There are significant restrictions on the selection of materials for the laminate film.

In addition, as mentioned above, compared to products such as beer cans that have already established marketability and are therefore stable in price, they do not have the ability to compete with the initial market price and are economically unstable. potentially have adverse conditions.

Therefore, when developing paper containers that have sufficient pressure resistance and gas barrier properties to function as containers for carbonated drinks such as beer and cider, it is necessary to develop paper containers that have potentially favorable material conditions. However, due to the extremely difficult technical and economic bottlenecks that exist,
This was a brake on its practical application.

By the way, as for the shape of the pressure-resistant container made of paper, as shown in FIG. 10 as a basic simple structure as mentioned above, for example, a spherical shell is formed on the inner peripheral surface of both ends of the cylindrical body material 2 manufactured in advance. A skirt portion 5.5' is formed on the periphery of the upper and lower lid members 3.3' with a shoulder portion 4 interposed therebetween. It is possible to adopt a length of 1 m that can be fitted and fixed with adhesive.

However, as mentioned above, it is extremely difficult to form such a spherical shell-shaped lid member 3.3' from paperboard due to its poor workability. Therefore, even if it is possible to curve the paper to a certain extent, this curved forming has the problem of degrading the pressure resistance and strength by forcibly separating the bonds between the fibers that make up the paper.

There is also the so-called wet slurry method, in which pulp fibers suspended in water are poured into a mold, shaped, and then dried to create a shape.
The power cost is high and it is not a good idea.

Regarding the skirt portion 5, ε', it is necessary to remove wrinkles that occur during bending, but this technique is generally impossible, and therefore, the skirt portion 5.
When the wrinkles 5' are bonded to the body material 2, a gap is created at the joint, making it difficult to maintain airtightness.

Therefore, despite the existence of many technical obstacles mentioned above,
Focusing on the many potential benefits of paper lids and paper containers, we have changed the original idea of molding lids from paperboard, and have changed the original idea of molding lids from paperboard to pulp, which is the raw material for paper. We have developed a technology for molding the above-mentioned lid material from a non-woven mat obtained by a dry process with the aim of molding it, and have explored the possibility of making the entire container substantially entirely made of paper. As a result of intensive research with the aim of perfecting containers for carbonated beverages such as beer and cider, as disclosed in the applicant's earlier patent application No. 180004/1983, a container for beer, etc. that can be stored and covered has been developed. Most of the part that comes into contact with the pressure drink forms a spherical curved surface, which fits into the body material.
As the lid material to which the joint seal is fixed, 20 to 25% by weight of a thermoplastic synthetic resin, such as low-density polyethylene, is made into a fiber or powder form and mixed in a hot air stream to bond the pulp fibers together. Developed a paper lid material for pressure-resistant containers, in which at least the spherical shell surface that contacts the pressurized beverage is laminated with a thermoplastic synthetic resin film, of a molded product obtained by hot press molding dry nonwoven fabric mats laminated to At present, we have created a structure that has sufficient pressure resistance and gas barrier properties against internal pressures of 5 to 10 kg/cm2 gauge pressure, thereby paving the way for practical application.

Although the foundation for practical application has been laid, various problems have arisen as the prospects for practical application become clearer.

That is, in order to weld and join the nonwoven mat lid material formed in this manner to the inner surface of the end of the body material, thermal welding of the skirt portion and the inner surface of the end portion of the body material, high frequency dielectric heating, ultraviolet heating, etc. are required. Techniques have been developed to perform sonic welding.

To briefly explain these thermal welding, high frequency welding, and ultrasonic welding, the first thermal welding is, for example, a heating element that is brought into contact with the outer surface of the end of the body material and heated. The lid material is fitted and inserted into the inner surface of the end portion, and the plastic film of ranenate is heated and welded by applying heat conduction to the lid material that is fitted and inserted into the inner surface of the end of the paper. Because the shell material has low thermal conductivity, welding takes a long time, and because the heating mode is from the outside of the shell material, the outer plastic film is exposed to high temperatures, causing the plastic film to melt and melt. Alternatively, it may be damaged due to thermal deterioration, causing problems such as pinholes and the like.

On the other hand, for the second high-frequency welding, a ring-shaped electrode is set inside the skirt part of the lid material that is inserted into the inner surface of the end joint of the shell material, and a plurality of divided electrodes are applied to the outer surface of the shell material. Tightening is performed while applying a surface pressure of 10 to 20 KQ/cm2 to the joint, and a high frequency current of 14 to 40 MHz is applied for a predetermined number of seconds using either the internal or external electrodes. This method promotes heat generation in the body material and lid material in between to weld the joint, but since the welding is performed under pressure, the welding surface is strong and the process can be completed in a short time. However, the welding characteristics are greatly influenced by the material properties of the laminated plastic film at the joint surface, for example,
There is not much of a problem if the plastic film is made of vinyl chloride, acrylic, cytidine, or butadiene resin, which has a large dielectric loss tangent, but if it is made of nonpolar polymers, such as polyolefin-based polyethylene or polypropylene resin,
There is a disadvantage that the dielectric loss tangent is too small and heat generation is poor, making welding impossible.Therefore, there is a disadvantage that there is no freedom in selecting the material of the plastic film to be laminated.

On the other hand, in ultrasonic welding, a circular jig is inserted into the inner surface of the lid material that is inserted and fitted into the joint on the inner surface of the end of the body material, and the jig is inserted into the inner surface of the lid material, which fits closely to the skirt portion. The ultrasonic application horn divided from
By applying ultrasonic waves of 15 to 40 kilohertz for about 0.4 to 3 seconds while applying surface pressure of cm2, high frequency vibration is generated on the welded surfaces of the opposing body material and lid material, which generates heat. , it has the advantage of being able to weld in a short time.

As the welding occurs due to high blood pressure, the opposing plastic films of the body material and the lid material soften and bite into the pulp fibers of both, resulting in tensile rupture of the welded portion during the heat welding. While the strength is about 10 kg/Cl112, there is an advantage that welding has a tensile breaking strength nearly twice that. This can be said to be the most suitable welding method for assembly.

<Problems to be Solved by the Invention> As mentioned above, even if the ultrasonic welding means that is most suitable for welding and joining the shell material and the lid material is used, problems that must be solved arise. This has been confirmed by experiments.

In other words, the welding strength is extremely high, which is extremely advantageous next to welded joints, but when welded parts are immersed in water colored with red ink, for example, and inspected for damage, we find that the welded parts are not damaged. There are cases in which finely damaged parts are often formed in the form of branches, which leads to defects such as pinholes, and ultimately leads to a decrease in the yield of the body material as a product.

Therefore, the welding of the skirt part, which increases the welding strength, which is an advantage of double-stage welding, is actually meaningless.Especially, when performing ultrasonic welding in multiple stages, the welding width is essentially limited. Although this method is advantageous in creating a pressure-resistant container with high pressure resistance, it can also cause damage to the plastic film, resulting in a decrease in strength. Ta.

The purpose of the present invention is to eliminate the conditions that inhibit the welding and joining of the lid material to the body material at the final stage, which has brought the paper body materials accumulated up to now to the realm of possibility based on the above-mentioned prior art. As a technical issue, it is possible to reliably weld the lid material to the body material to meet mass production, improve product yield and reduce costs, improve product reliability, and benefit the field of container use in the beverage industry. The purpose of the present invention is to provide an excellent method for assembling paper pressure-resistant containers.

<Means/effects for solving the problems> In order to solve the above-mentioned problems, the structure of the present invention, which is summarized in the above-mentioned claims, is based on a gas barrier film attached with a predetermined shape. When joining the body material and the lid material molded from the aforementioned mat, or the lid material that has three paper shells and a skirt part made of high-density polyethylene or the like that is insert-molded, each The molded body material and lid material are relatively fitted inside the end of the lid material, and a welding jig is set on the inner surface of the welded part of the lid material, and the welding is performed. When irradiating ultrasonic waves to the body material of the body with an ultrasonic application horn facing the outer surface, metal is applied to the end face of the welded part of the body material, or the outer face, or both of the outer faces of the welded part of the body material. A propagation material that induces and easily propagates pressure waves such as
By applying ultrasonic waves of 15 to 40 kilohertz for about 0.4 to 3 seconds using an ultrasonic horn while applying a surface pressure of /cm2, the plastic on the welded surfaces of the opposing body material and lid material is exposed to high frequency. The vibration generates heat and welding of the two is completed in a short time, and the pressure source of the irradiated ultrasonic waves is guided to the abutted propagation material at the welded joint at the end of the body material. The energy of the irradiated ultrasonic wave propagates to the propagation material, and the energy of the irradiated ultrasonic wave is propagated to the propagation material without being accumulated in the joint, and the pressure wave is dissipated to the propagation material, causing a kind of damage to the joint. By providing a grounding effect, the gas barrier laminate film of the body material and the lid material or the plastic material at the joint part is reliably prevented from being damaged such as scorching or pinhole formation, thereby improving the product yield; Technical measures have been taken to increase reliability.

<Embodiment> Next, one embodiment of the present invention will be described below based on the drawings of FIGS. 1 to 12. In addition, the same reference numerals are used for the same parts as in FIG. 13.

The embodiment shown in Figure 1.6 is one embodiment.

Thus, the illustrated embodiment is a mode of manufacturing and assembling a pressure-resistant container for storing beer as a carbonated beverage, and is basically a mode of assembling a pressure-resistant container 1' of a drinking pot shown in FIG. The monthly member consists of a straight cylindrical body member 2, upper and lower cover members 3 and 3', and these are connected to the body member 2 in the order of the upper cover member 3 and the lower cover member 3'.
The body material 2 is assembled by ultrasonic welding and joining, and as mentioned above, much technical research and development has been done so far with no prospect of practical application.
As the material, pulp fibers, fibers such as plastics other than pulp fibers, powder films, etc. can be used in combination, and the weight ratio of pulp fibers is at least 50% by weight,
It has substantially the same characteristics as general pure paper products, such as high combustibility and crushability, and it occupies substantially the majority of the components of pressure containers.

As for the upper and lower lid members 3 and 3', as mentioned above, one made of a non-woven mat is used. For example, 20 to 25% by weight of low-density polyethylene thermoplastic resin is added to the valve fibers as a binder in the form of fibers. , or mix it into a powder and mix it in a hot air stream to make pulp! Connect I-Wei comrades with each other,
A dry nonwoven fabric mat is formed by laminating a mat having a thickness of 20 to 50 mm and a bulk specific gravity of about 0.05, which is then formed into a spherical shell shape by hot pressing.

A waterproof and/or gas barrier plastic film is laminated on both sides of the body material 2 and the lid material 3.3', and the material of the laminate film is, for example, low density Polyethylene, low pressure low density polyethylene 1. Polyolefin resins such as high-density polyethylene and polypropylene, vinylidene chloride resins, polyvinyl alcohol resins, acrylonitrile resins, etc. can be used.

Regarding gas barrier properties, in a stable state, at 1 atm, temperature 25°C, and relative humidity 50%, the thickness is 1IIl.
The permeability of a ++ film is determined by the gas capacity (CC) that permeates per 1 m2 in 24 hours, but the above gas barrier film has a permeability of about 200 for gases such as oxygen, carbon dioxide, and nitrogen. The laminated film is as follows.

In manufacturing and assembling the pressure container 1' shown in FIG. The assembly process is such that ultrasonic welding is performed on the inner circumferential surfaces of the upper and lower ends of the body material 2 as joint parts to integrate them.

As an example of the assembly jig for the upper lid material 3, No. 2.3
．． A jig 6 shown in FIG.
The blocks that were inserted and fitted into the upper end of the body material 2 with high precision were then set on the supports 10 and 11 provided at the upper and lower ends of the rotating shaft 9 of the rotating holder 8, and the blocks were placed in the supporting bodies 10 and 11 provided at the upper and lower ends of the rotating shaft 9 of the rotating holder 8. A jig 9 of the holder 8 is rotatably supported in a U-shaped U groove 14 of a stand 13 fixed to the end of the jig 6 via a bolt 12.

The embodiment shown in FIG. 2 is an embodiment in which the upper cover member 3 is first welded and fixed to the body member 2 as described above. A predetermined metal propagation material 16 shown in FIG.
Of the end surface 18 and the outer surface 19 (shown in FIGS. 7 to 9) of the joint portion 17, as shown in FIG. has been done.

In this case, the contact pressing force of the propagation material 16 against the joint portion 17 of the body material 2 is determined to a predetermined value by adjusting the bolt 12 of the bracket 15 with respect to the jig 6. There is.

Incidentally, 2o shown in FIG. 2 is a well-known ultrasonic application horn, and together with a booster of an air horn type cylinder (not shown), etc., the joint part 17 of the body material 2 to the upper lid material 3 is used.
For example, in connection with the jig 6, 45 shafts are provided around the circumference in the circumferential direction, and as shown in FIG. By rotating the joint 17, ultrasonic waves can be irradiated all around the joint 17.

After joining and welding the upper cover material 3 to the body material 2, the holder 8 is removed from the jig 6 and pulled down in the axial direction of the body material 2 to complete the drawing welding.

Then, in the case of the lower lid member 3', the lower end of the body member is inserted and fitted, and the support 10' of the holder 8' is again inserted into the inner surface of the joint part of the lid member 3', and the parts are joined and welded in the same manner as described above. I do.

The manner in which the upper cover member 3 and lower cover member 3' are joined and welded to the body member 2 is schematically illustrated in FIG. 5.6.

The propagation material 16 shown in FIG. 5.6 is slightly deformed from the propagation material 16 shown in FIG. 2.4 in the vertical type.

As shown in FIG. 5, the upper cover member 3 is set by inserting and fitting it into the upper end of the body member 2 in advance, and in that state, each ultrasonic application horn 20 is attached to the joint portion 17 on the outer surface. As mentioned above, while applying a surface pressure of 10 to 50 K (1/cm2), ultrasonic waves of 15 to 40 kilohertz were applied for about 0.4 to 3 seconds.

As a result, the laminate film at the joint between the inner surface of the body member 2 and the outer surface of the lid member 3 generates heat, and welding is performed in a short time.

Therefore, the heated and melted plastic film softens, and the paper pulp fibers of the body material and the internal pulp of the lid material become soft.
It bites into the li navy blue and welds and bonds with high tensile breaking strength,
Both are made into one.

Therefore, as described above, the body material and the lid material are rotated 45 degrees together with the rotating shaft 9 by a drive device (not shown), and the same pressing force as described above is applied to the joint surface again.
Ultrasonic irradiation is performed to perform welding and welding of the entire circumference of the joint.

When the welding and fixing of the upper lid material 3 to the body material 2 is completed, welding of the lower end of the lower end of the body material 2 of the lower lid material 3' shown in FIG. conduct.

In this way, the upper and lower lid members 3.3' are joined and fixed to the body member 2 shown in FIG. 1.

In the welding process, when the joint part 17 of the upper cover member 3 and the lower cover member 3' is irradiated with ultrasonic waves at the end of the shell member 2, as shown in FIG. Since the propagation material 16 is pressed against its end surface 18 and outer surface 19, the ultrasonic waves irradiated from the ultrasonic wave applying horn 20 create pressure within the portion of the body material in the ultrasonic section 17. The waves are immediately propagated and transmitted to the propagation material 16 without being trapped, and therefore, due to the energy of the pressure waves,
There are no scorches, minute branch-like cracks, or bottle balls at the ends of the body material 2, and therefore, the body material 2 of the manufactured paper pressure-resistant container 1' as shown in FIG. At the junction of the lid member 3.3', no defects such as breakage occur in the entire skirt portion 5.5'.

For this test, a sample of the product is immersed in a solution containing red ink, etc., as described above, and the state of penetration is observed.

According to experiments, no defects were observed in this invention, and extremely good product yields were obtained.

The contact state of the propagation material 16 at the end 17 of the body material 2 is such that both ends are in contact with the end surface 18 and the outer circumferential surface 19 as shown in FIG. 7, but as shown in FIG. 18 may be used, or, as in the embodiment shown in FIG. 9, it may be in contact with only the outer peripheral surface 19. Depending on the material shape of the lid material 3.3', the appropriate selection may be made based on theory and experiment.
6. 16' and 16' are not necessarily square in cross section, and can be appropriately selected such as tapered or gourd shaped.
Further, the material is not limited to metal, and may be appropriately selected from materials such as plastic or wood, which have a good grounding effect and allow the ultrasonic waves transmitted from the body material to easily escape.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments, and in each of the above-mentioned embodiments, the substrate for both the body material and the lid material is a pressure-resistant container. The joint may be, for example, a ring-shaped joint formed by injection molding of high-density polyethylene, and in this case, the spherical shell for the joint material may be made of the matte, or
Various embodiments can be adopted, such as a press-molded paperboard product or even an insert-manufactured product.

Further, as an example of a design modification of the present invention, it is applicable not only to welding and welding a body material to a body material, but also to the case where a fully open type body material and a body material are joined together.

Of course, the present invention is applicable not only to the pressure-resistant containers for beer of the above-mentioned embodiments, but also to pressure waves for cider and the like.

<Effects of the Invention> According to the present invention, theoretically, when manufacturing a paper pressure wave as described above, it is possible to assemble it into an integral shape from the planar shape of the paper material, based on the premise that a three-dimensional shape is required for the stored beverage. In general, when joining the upper and lower lid materials to the body material, the most basic form is selected based on the selection conditions, and from the viewpoint of gas barrier properties, the surface that comes into contact with the beverage must have waterproof and/or gas barrier properties. Although ultrasonic welding is the most preferable among the various welding methods mentioned above because the film is attached, ultrasonic waves emitted from the ultrasonic application horn from the outer surface of the body material at the joint part are The welding builds up at the edges of the body and causes branch-like damage, scorch, and pinholes on the edges of the body and the shoulder of the lid at the joints, or on the ends of the skirt. Therefore, reliable tensile strength is guaranteed at the joint between the end of the shell and the skirt of the M-piece, which is the most delicate part in a pressure vessel, and gas barrier properties are also ensured. It has the excellent effect of increasing product reliability, and improving product yield.

Therefore, at the joint end of the body material, a propagation material such as metal that can release ultrasonic pressure waves is brought into contact with and extended on either the end surface or the outer surface, or both. The pressure waves of the irradiated ultrasonic waves are reliably propagated from the end of the body member and the end of the cover member to the propagation member, thereby achieving an excellent effect of preventing the above-mentioned damage.

However, since the propagation material only needs to be provided in the assembly jig when performing ultrasonic irradiation, it is necessary to perform special processing on the pressure waves or attach special members to Mu. The pressure vessel body can have a simple structure as designed, and
Since the assembly jig only needs to bring the propagation material into contact with the body material, it is not only simple in structure but also easy to operate, and there are advantages in that no maintenance or inspection is required.

[Brief explanation of drawings]

1 to 7 are explanatory diagrams of one embodiment, in which FIG. 1 is a vertical cross-sectional view of a paper material as a product, FIG. 2 is a vertical cross-sectional view of an assembly jig, and FIG. Figure 4 is a front view of one part of the jig, Figure 4 is a perspective view of the propagation material, Figure 5 is a partial cross-sectional view of the welded joint of the upper lid, Figure 6 is a partial cross-sectional view of the welded joint of the lower lid, and Figure 7 is a partial cross-sectional view of the welded joint of the lower lid. FIGS. 8 and 9 are side views of the propagation material in contact with the ends of the body, FIGS. 8 and 9 are side views of other embodiments equivalent to FIG. 7, and FIG. 10 is a cross-sectional view of a pressure vessel based on the prior art. 1'... Paper pressure container, 2... Trunk material, 3.3'
...lid material, 17...joint part, 16...propagation material,

Claims (3)

[Claims] (1) In an assembly method that includes a step of irradiating ultrasonic waves to the joint part of the body material and lid material of a paper pressure-resistant container to weld and join them,
A method for assembling a paper pressure-resistant container, characterized in that during the ultrasonic irradiation, an ultrasonic propagation material is brought into contact with the joint portion of the body material so that the pressure waves of the ultrasonic wave are dissipated from the end of the member. . (2) The method for assembling a paper pressure-resistant container according to claim 1, wherein the contact portion of the propagation material is an end face of the body material. (3) The method for assembling a paper pressure-resistant container according to claim 1, wherein the contact portion of the propagation material is an outer surface of an end of the body material.