JPH0459210B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a pressure-resistant sealed container using a paper container body and a container lid for use in beverage cans and the like.

(Prior Art) In recent years, liquid-sealed containers using paper container bodies, such as composite cans, have been widely used due to resource conservation and waste disposal issues. For this kind of thing, the fourth
As shown in the figure, there is a product in which a metal container lid a is attached to a paper container body b, and its manufacturing method is performed by double-sealing the opening edge of the container body b, similar to conventional metal can bodies. There is. However, unlike a metal body, the paper container body b lacks extensibility, so when it is rolled up, the folded part d of the folded flange part c hardens, and the seaming wall part e and chuck wall part f of the metal container lid a harden. If the pressure in the container body b is high, the container will break at the part compressed by the folded part d or the seaming wall part e and the chuck wall part f, and the container will be in a weakened state. Lid a sometimes came off.

For this reason, it could not be used as a container for carbonated beverages that require a pressure resistance of 10 kg/cm ² .

On the other hand, the peripheral edge of the container lid is fitted to the outer peripheral surface of the opening of the metal container lid instead of the paper container body, and the outer peripheral surface and the inner surface of the peripheral edge of the container lid are heated to melt and cool the adhesive. A method for manufacturing a metal container to be bonded is disclosed in JP-A-58-61936. However, when such a manufacturing method is adopted for paper container bodies, the opening edge of the paper container body is exposed inside the container, so it is constantly in contact with the liquid stored in the container, and the liquid is exposed to the inside of the container. This was inappropriate because it penetrated the paper tissue of the container body from the opening edge and swelled, causing delamination and weakening the adhesive part of the container body.

(Problems to be Solved by the Invention) The present invention solves such inconveniences by covering the opening of the container body with a reinforcing member so that the connection between the container body and the container lid can be maintained even if the internal pressure is constantly high. The object of the present invention is to provide a method for manufacturing a sealed container having a paper container body that is robust and has excellent pressure resistance.

(Means for Solving the Problem) The present invention solves the above-mentioned problem. A reinforcing member with a matching shape is provided by gluing, and the peripheral wall portion of the container lid, which has a panel portion and a peripheral wall portion hanging down and connected to the entire periphery of the panel portion, is externally fitted onto the container body, and bonded at the corresponding position of the reinforcing member. In a method for manufacturing a container, a reinforcing member having a cross-sectional shape of ∩ and consisting of an outer reinforcing part, an inner reinforcing part, and a connecting part that integrally covers the outer surface, end surface, and inner surface of the opening of the container body is added to the entire periphery of the opening. The process of applying a coating to the inner reinforcing part of the reinforcing member on the inner surface side of the container body is immovably restricted, and the surface of the outer reinforcing part of the reinforcing member on the outer surface side of the container body is pressed to remove the outer reinforcing part. embedding into the container body and arranging the surface of the outer reinforcing portion on the same plane as the outer peripheral surface of the container body, and heating the container body and the reinforcing member to place the reinforcing member at the opening of the container body. A process of gluing;
The present invention is characterized by comprising a step of externally fitting and attaching the container lid to the opening of the container body, and a step of adhering the peripheral wall portion of the container lid to the container body at a corresponding position of the reinforcing member.

(Example) FIGS. 1A to 1D show an example of the manufacturing process of the sealed container of the present invention.

First, each member of the sealed container used in carrying out the present invention, that is, the container body 1, the reinforcing member 4, and the container lid 5 will be explained.

The container body 1 is made of paper and is a conventional composite container body such as a spiral, convolute, or single wall, and is a cylindrical body with an opening 2 and has an arbitrary shape such as a circular or square cross section It's okay to be. The inner and outer surfaces of the container body 1 are coated with a synthetic resin coating 3 that has good thermal adhesion to metals, such as a metal ion crosslinked polyolefin resin (ionomer resin) or a polyolefin resin containing polar carboxyl groups. Alternatively, the container body 1 was waterproofed by adhering aluminum foil to the inner and outer surfaces and coating the above synthetic resin film on the front side.

The reinforcing member 4 is made of a synthetic resin material that is the same as or compatible with the synthetic resin coating 3, and covers the entire circumference of the opening 2 of the container body 1 on the outer surface 2a.
The overall shape is cylindrical with an approximately ∩ cross section consisting of an outer reinforcing portion 4a, an inner reinforcing portion 4b, and a connecting portion 4c that integrally cover each of these surfaces 2a, 2b, and 2c from the side to the inner surface 2b through the end surface 2c. It is of a similar shape. Then, the open end side of the reinforcing member 4, that is, the outer reinforcing portion 4a
The lower end portion of the inner reinforcing portion 4b is provided with an inclined surface 4d extending downward from the inner side toward the outer side, and the connecting portion 4c is formed into a curved shape.

The container lid 5 is made of a metal material such as aluminum, stain-free steel, or tinplate, and is connected to a panel portion 6 along its entire periphery.
It is a cup-shaped bottomed cylindrical body consisting of a peripheral wall part 7 which is fitted to the outer surface 2a side of the opening 2 of the container body 1 in a hanging state, and the inner surface side of the container lid 5 is thermally bonded. A coating 8 of the above-mentioned synthetic resin is applied.

Next, a method for manufacturing a sealed container will be explained with reference to the drawings.

First, as shown in FIG. 1A, the opening 2 of the container body 1 is
The end surface 2 of the opening 2 is attached to the open end side of the reinforcing member 4 so that the outer reinforcing part 4a of the reinforcing member 4 comes into contact with the outer surface 2a of the reinforcing member 4.
The reinforcing member 4 is inserted from the c side to cover the entire circumference of the opening 2.

Since the reinforcing member 4 is provided with an inclined surface 4d on the open end side, this serves as a guide and the coating can be easily attached to the opening 2.

Next, as shown in FIG. 1B, the drawing die 21 used in this step is in contact with the outer circumferential surface 9 of the container body and the surface of the reinforcing member 4, and is provided with a groove 22 having a generally reverse concave cross section around the entire circumference of the opening 2. Further, the outer diameter of the groove 22 is the same as the outer diameter of the container body 1, and a pair of heating devices 23 are further incorporated. If the reinforcing member 4 is inserted into the groove 22 of the drawing die 21 from the connecting part 4c side of the part where the reinforcing member 4 is covered and attached to the opening 2 of the container body 1, the outer reinforcing part 4a of the reinforcing member 4 will be inserted into the outer surface 22a of the groove 22. If the coated portion is further press-fitted into the groove 22 while regulating the surface 4e of the inner reinforcing portion 4b of the reinforcing member 4, the outer circumferential surface 9 of the container shell 1 and The surface 10 of the outer reinforcing portion 4a of the reinforcing member 4 is the outer surface 2 of the groove 22.
2a, the connecting portion 4c of the reinforcing member 4 is connected to the inner surface 22c of the groove 22, and the connecting portion 4c of the reinforcing member 4 is connected to the inner reinforcing portion 4b of the reinforcing member 4.
are in contact with the inner surface 22b of the groove 22, and the reinforcing member 4 is compressed by the groove 22, so that the opening 2 of the container body 1 is inwardly moved together with the outer reinforcing portion 4a of the reinforcing member 4 that projects outward. Only the opening 2 that is narrowed in the direction and in contact with the outer reinforcing part 4a is compressed by the thickness of the outer reinforcing part 4a, and the part of the outer reinforcing part 4a is embedded in the container body 1. The narrowed opening 2 and the reinforcing member 4 are heated by a heating device 23 built into the drawing die 21.
The reinforcing member 4 is heated and softened to fix the embedded state, and the surface 10 of the outer reinforcing portion 4a of the reinforcing member 4 is disposed on the same plane as the outer circumferential surface 9 of the container body. Next, the opening 2 of the container body 1
The coating 3 and the reinforcing member 4 applied to the inner and outer surfaces are melted and bonded together.

Note that the drawing die 21 used in this step may be an integral type with the grooves 22 of the above-mentioned structure directly provided thereon, as shown in FIG.
The above-mentioned structure is obtained by integrating split molds, each of which has been made in advance, into an outer aperture mold (not shown) comprising an aperture outer mold (not shown) and an aperture inner mold (not shown) comprising an inner surface 22b and a rear surface 22c of the groove 22, respectively, by an appropriate means. A drawing die 21 having grooves 22 may be used.

Next, as shown in FIG. 1C, the container lid 5 is externally fitted onto the reinforcing member 4 that was covered and attached to the opening 2 of the container body 1 in the previous step, and the peripheral wall of the container lid 5 is attached to the outer surface 2a of the opening 2. The inner surfaces of the parts 7 and 7 are fitted together with the reinforcing member 4 interposed therebetween.

If an outwardly curved portion 11 is provided at the lower end of the peripheral wall 7 of the container lid 5, this curved portion 11 will serve as a guide to facilitate the outer fitting of the container lid 5 onto the reinforcing member 4. Highly sexual. Also, the connecting portion 4 of the reinforcing member 4
Since c is configured in a curved shape, the efficiency of the above-mentioned external fitting process is further improved.

Next, as shown in FIG. 1D, the reinforcing member 4 and the container lid 5 are attached.
The mold surface 24a of the lid pressure bonding mold 24 incorporating the heating device 25 is pressed against the outer fitting part of the heating device 2.
5, the peripheral wall 7 of the container lid 5 and the reinforcing member 4 are heated to melt the reinforcing member 4 and the coating 8 applied to the inner surface of the container lid 5, and the peripheral wall 7 is heated at the corresponding position of the reinforcing member 4. Glue it to the container body 1.

Further, instead of the above-described method of bonding the reinforcing member 4 and the peripheral wall 7 of the container lid 5, an adhesive may be used to bond the two together.

The heating devices 23 and 25 to be incorporated into the drawing die 21 and the lid pressure bonding die 24 include a high frequency induction heating device, an electric heating device, and a hot air device, which are selected depending on the size and shape of the sealed container.

Through the above steps, the reinforcing member 4 is covered and attached to the opening 2 of the container body 1 as shown in FIGS. 1 and 2.
A sealed container is manufactured by fitting the container lid 5 on the outside through the container lid 5. The end surface 2c of the opening 2 of the container body 1 is isolated from the contents to prevent the container body 1 from weakening due to liquid penetration from the end surface 2c. To obtain a sealed container with improved pressure resistance and sealing performance without breaking the joint part with the container lid 5.

Note that while regulating the surface 4e of the inner reinforcing portion 4b of the reinforcing member 4 on the inner surface of the container body 1, the surface 10 of the outer reinforcing portion 4a of the reinforcing member 4 on the outer surface of the container body 1 is
In the process of pressing and embedding the outer reinforcing part 4a into the container body 1, if the surface 10 of the outer reinforcing part 4a is not flush with the outer circumferential surface 9 of the container body but is arranged in a somewhat protruding state. Also, the step of fitting and bonding the peripheral wall portion 7 of the container lid 5 onto the container body 1 can be carried out without any problem.

Further, the reinforcing member 4 used in the embodiment shown in FIGS. 1 and 2 has its outer reinforcing portion 4a shorter than the length of the peripheral wall 7 of the container lid 5, but the reinforcing member 4 used in the embodiment shown in FIG. Thus, the length of the outer reinforcing portion 4a of the reinforcing member 4 may be formed to be approximately the same length as the peripheral wall portion 7 of the container lid 5.

(Effects of the Invention) As described above, according to the present invention, a reinforcing member having a cross-sectional shape of ∩ and consisting of an outer reinforcing part, an inner reinforcing part, and a connecting part integrally covers the outer surface, end surface, and inner surface of the opening of the container body. a step of covering the entire circumference of the opening;
The surface of the inner reinforcing part of the reinforcing member on the inner surface of the container body is immovably restricted, and the surface of the outer reinforcing part of the reinforcing member on the outer surface of the container body is pressed to embed the outer reinforcing part in the container shell. a step of placing the surface of the outer reinforcing portion on the same plane as the outer peripheral surface of the container body; a step of heating the container body and the reinforcing member to bond the reinforcing member to the opening of the container body; and a step of bonding the reinforcing member to the opening of the container body. Through the reinforcing member that is covered and attached to the opening of the container body, there are a step of fitting and attaching it to the opening of the container body, and a step of adhering the peripheral wall of the container lid to the container body at the corresponding position of the reinforcing member. A container lid is fitted onto the outside to produce a sealed container having a paper container body.

Therefore, by regulating the surface of the inner reinforcing part of the reinforcing member covered and attached to the opening of the container body and pressing the surface of the outer reinforcing part, the reinforcing member and a part of the opening of the container shell are simultaneously compressed. By embedding the outer reinforcing portion in the container body and fixing it in the embedded state by heating, the surface of the outer reinforcing portion of the reinforcing member can be easily arranged on the same plane as the outer peripheral surface of the container body. Since the opening of the container body is coated with a reinforcing member, there is no damage to the container body when the container lid is fitted over it and pressure bonded, and the end face of the opening is also covered, so there is no weakening from the end face. Therefore, it is possible to continuously and efficiently manufacture sealed containers in which the joint between the container body and the container lid is strong and has excellent pressure resistance and sealing performance.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one example of the manufacturing process of the present invention, FIG. 2 is a partially cutaway side view showing an example of a sealed container obtained by the manufacturing method of the present invention, and FIG. The figure is a partially enlarged sectional view of a modified example of a sealed container obtained by the manufacturing method of the present invention, and FIG. 4 is a partially enlarged sectional view of a conventional product. 1... Container body, 2... Opening, 2a... Outer surface,
2b...inner surface, 2c...end surface, 4...reinforcing member,
4a...Outer reinforcement part, 4b...Inner reinforcement part, 4c...
Connecting portion, 4e...Surface of inner reinforcing portion, 5... Container lid, 6... Panel portion, 7... Peripheral wall portion, 9... Outer peripheral surface of container body, 10... Surface of outer reinforcing portion.

Claims (1)

[Claims] 1. A reinforcing member with a shape matching the cross-sectional shape of the opening is attached to the entire circumference of the opening of a cylindrical paper container body whose inner surface has been waterproofed, and the reinforcing member is attached to the panel and the entire periphery thereof. A method for manufacturing a container in which a peripheral wall of a container lid having a peripheral wall connected to the container body is fitted onto the container body and bonded at a corresponding position of a reinforcing member, the outer surface, the end surface, and the inner surface of the opening of the container body are integrated. a step of covering the entire circumference of the opening with a reinforcing member having a ∩-shaped cross section and comprising an outer reinforcing portion, an inner reinforcing portion, and a connecting portion;
The surface of the inner reinforcing part of the reinforcing member on the inner surface of the container body is immovably restricted, and the surface of the outer reinforcing part of the reinforcing member on the outer surface of the container body is pressed to embed the outer reinforcing part in the container shell. a step of placing the surface of the outer reinforcing portion on the same plane as the outer peripheral surface of the container body; a step of heating the container body and the reinforcing member to bond the reinforcing member to the opening of the container body; and a step of bonding the reinforcing member to the opening of the container body. A sealed container having a paper container body, characterized by comprising the steps of fitting and attaching the container lid to the opening of the container body, and adhering the peripheral wall of the container lid to the container body at a corresponding position of the reinforcing member. manufacturing method.