JPH0459209B2 - - 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 third
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 eliminates such inconveniences and covers the opening of the container body with a reinforcing member, so that even if the internal pressure is constantly high, the joint between the container body and the container lid is An object of the present invention is to provide a method for manufacturing a sealed container having a paper container body which is robust and has excellent pressure resistance, and which has a reduced diameter portion at the opening so that there is no unevenness on the outer circumferential surface of the container and is easy to align and arrange. It is.

(Means for Solving the Problems) The present invention solves the above-mentioned problems, and has a cross-sectional shape formed on the entire circumference of the opening of a cylindrical paper container body whose inner surface is waterproofed. 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 the method for manufacturing a container, the method includes a step of covering the entire circumference of the opening with a reinforcing member that integrally covers the outer surface, end surface, and inner surface of the opening of the container body; A neck-in part that press-fits a container body covered with a reinforcing member into a groove with the following diameter, narrows the opening of the container body together with the reinforcing member, and heats it to reduce the diameter of the reinforcing member and create a diameter-reduced part in the opening. a step of adhering a reinforcing member to the opening of the container body; a step of externally fitting the container lid to the opening of the container body and arranging the circumferential wall portion in the reduced diameter portion and attaching the container lid; The outer circumferential surface of the circumferential wall of the container lid is disposed on the same plane or inwardly as the outer circumferential surface of the container body by the step of adhering the circumferential wall 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 extends over the entire circumference of the opening 2 of the container body 1 to the outer surface 2a.
It has an approximately ∩ cross-sectional shape and is composed of an outer reinforcing part 4a, an inner reinforcing part 4a, and a connecting part 4c that integrally cover each of these surfaces 2a, 2b, and 2c from the side to the end surface 2c to the inner surface 2b. The shape is cylindrical. The open end side of the reinforcing member 4, that is, the lower end portion of the outer reinforcing portion 4a is provided with a sloped surface 4d directed outward from the inside, and the lower end portion of the inner reinforcing portion 4b is also provided with a similar sloped surface 4e. The reinforcing portion 4b is configured to have a slope portion 4g extending from the upper end to the lower end so that the lower end portion becomes a thick portion 4f, and the connecting portion 4c is configured to have 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 onto the outer surface 2a of the opening 2 of the container body 1 in a hanging state. The inner surface of the container lid 5 is coated with the heat-adhesive synthetic resin coating 8 described above.

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.

Incidentally, both inclined surfaces 4d and 4e are provided on the open end side of the reinforcing member 4.
Since this is provided, it serves as a guide and facilitates the installation of the coating into the opening 2, making the installation process simple and highly productive.

Next, as shown in FIG. 1B, a drawing die 21 used in this step is provided with a groove 22 having a substantially inverted concave cross-section that contacts the outer peripheral surface 9 of the container body and the surface of the reinforcing member 4 and corresponds to the entire circumference of the opening 2. and the outer diameter of the groove 22 is the same as the outer diameter of the container body 1, and the heating device 2
3 is incorporated. And this drawing die 2
A reinforcing member 4 is inserted into the opening 2 of the container body 1 in the groove 22 of the container body 1.
If the outer reinforcing part 4a of the reinforcing member 4 is inserted from the connecting part 4c side of the covered part, the outer reinforcing part 4a of the reinforcing member 4 will be inserted into the outer surface 2 of the groove 22.
2a, and if the coated part is further press-fitted into the groove 22, the outer circumferential surface 9 of the container body and the outer reinforcing part 4a of the reinforcing member 4 will be pushed into the outer surface of the groove 22. 22a, the connecting portion 4c of the reinforcing member 4 is in contact with the inner surface 22c of the groove 22, and the inner reinforcing portion 4b of the reinforcing member 4 is in contact with the inner surface 22b of the groove 22, so that the reinforcing member 4 is pinched in the groove 22. Thus, together with the reinforcing member 4, the opening 2 of the container body 1 is narrowed inward, and the outer circumferential surface of the reinforcing member 4 is reduced in diameter by the thickness of the container lid 5 from the outer circumferential surface 9 of the container body. Then, the narrowed opening 2 and the reinforcing member 4 are connected to the drawing mold 2.
The container body 1 is heated and softened by the heating device 23 incorporated in the container body 1 and fixed in a reduced diameter state, and the neck-in portion 10 connects the reduced diameter portion 11 having a smaller diameter than the outer circumferential surface 9 of the container body 1 to the opening of the container body 1. Form in part 2. Subsequently, a coating 3 is applied to the inner and outer surfaces of the opening 2 of the container body 1.
and reinforcing member 4 are melted and bonded together.

Note that the coating 3 and the reinforcing member 4 may be bonded together at the same time as the reduced diameter portion 11 is formed.

The inner reinforcing part 4b of the reinforcing member 4 has a thick part 4f at the lower end and an inclined part 4 extending from the upper end to the lower end.
g, the opening 2 can be recessed inward along the inclined surface 4d at the lower end of the outer reinforcing part 4a, and the shape of the neck-in part 10 that provides the reduced diameter part 11 can be reliably and easily formed. obtain.

Note that the container body 1 and the reinforcing member 4 are reduced in diameter to form the opening 2.
The drawing die 21 used to form the neck-in part 10 that provides the reduced diameter part 11 may be an integral die with the groove 22 of the above-mentioned structure directly provided therein, or the first
As shown in Figure B, split molds, each of which has been manufactured in advance, are integrated into an aperture outer mold 211 having an outer surface 22a of the groove 22 and an aperture inner mold 212 having an inner surface 22b and a rear surface 22c of the groove 22, respectively, by appropriate means. This may also be used as the drawing die 21 having the groove 22 configured as described above.

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.

Incidentally, if an outwardly curved portion 12 is provided at the lower end portion of the peripheral wall portion 7 of the container lid 5 as shown in FIG. 1C,
This curved portion 12 serves as a guide and allows the container lid 5 to be easily fitted onto the reinforcing member 4, resulting in high productivity.
Further, since the connecting portion 4c of the reinforcing member 4 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.
Lid pressure bonding mold 2 incorporating a heating device 25 in the outer fitting part of the lid
4 and press the mold surface 24a 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. Also, the reinforcing member 4
Instead of the above-described method of bonding the container lid 5 to the peripheral wall 7 of the container lid 5, an adhesive may be used to bond the two together.

In addition, when using the container lid 5 in which the curved part 12 is provided at the lower end portion of the peripheral wall part 7, the outer peripheral surface of the curved part 12 and the peripheral wall part outer peripheral surface 13 are aligned at the same time as pressing with the lid crimping die 24. Press so that it is on the surface. 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, a sealed container is manufactured in which the outer circumferential surface 13 of the peripheral wall portion of the container lid 5 is disposed on the same plane or inwardly as the outer circumferential surface 9 of the container body, as shown in FIGS. 1 and 2. By using a reinforcing member 4 in which an inner reinforcing part 4b and a connecting part 4c are integrally formed with an outer reinforcing part 4a, the end face 2c of the opening 2 of the container body 1 is isolated from the contents, and the liquid is separated from the end face 2c. This seal prevents the container body 1 from weakening due to penetration of water, and prevents the joint between the container body 1 and the container lid 5 from being destroyed by contents that generate high internal pressure, improving pressure resistance and sealing performance. Get a container.

(Effects of the Invention) As described above, according to the present invention, a reinforcing member that integrally covers the outer surface, end surface, and inner surface of the opening of the container body is attached to the entire circumference of the opening; A container body covered with a reinforcing member is press-fitted into a groove having a diameter equal to or less than the outer diameter of the container body, and the opening of the container body is narrowed together with the reinforcing member, and heated to reduce the diameter of the reinforcing member and fill the opening. A step of forming a neck-in portion that provides a reduced diameter portion, a step of adhering a reinforcing member to the opening of the container body, and a step of fitting the container lid to the opening of the container body and arranging the peripheral wall portion in the reduced diameter portion. The mounting process and the process of gluing the peripheral wall of the container lid at the corresponding position on the reinforcing member allow the outer peripheral surface of the peripheral wall of the container lid to be on the same plane or inward as the outer peripheral surface of the container body, thereby forming a paper container body. Manufacture a sealed container having:

Therefore, by press-fitting the reinforcing member covering the opening of the container body into the groove of the drawing die, the reinforcing member and the container body are simultaneously reduced in diameter, and then fixed in the reduced diameter state by heating. It is possible to easily form a neck-in part that gives a diameter reduction part to the opening, and since the opening of the container body is covered with a reinforcing member, there is no damage to the container body when fitting the container lid thereon and press-bonding it. In addition, the end face of the opening is also coated to prevent weakening from the end face, so the joint between the container body and the container lid is strong and has excellent pressure resistance and sealing performance, and furthermore, a reduced diameter part is formed at the opening. Therefore, it is possible to continuously and efficiently manufacture sealed containers that have no irregularities on the outer circumferential surface of the containers and are easy to align and arrange.

[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 cross-sectional view of a conventional product. 1... Container body, 2... Opening, 2a... Outer surface,
2b...inner surface, 2c...end surface, 4...reinforcing member,
5... Container lid, 6... Panel part, 7... Peripheral wall part,
9...Container body outer peripheral surface, 10...Neck-in part, 1
1... Reduced diameter part, 13... Outer peripheral surface of peripheral wall part, 21...
Drawing die, 22...groove.

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 of the container. In 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 to cover the opening, and press-fitting the container body covered with the reinforcing member into a groove with a diameter equal to or less than the outer diameter of the container body provided in the drawing die to form the reinforcing member. a step of narrowing the opening of the container body and heating it to form a neck-in portion that reduces the diameter of the reinforcing member and gives a diameter-reduced portion to the opening; a step of bonding the reinforcing member to the opening of the container body; The outer periphery of the peripheral wall of the container lid is improved by fitting the lid over the opening of the container body and arranging and attaching the peripheral wall to the reduced diameter part, and adhering the peripheral wall of the container lid at the corresponding position of the reinforcing member. A method for manufacturing a sealed container having a paper container body, characterized in that the surface is disposed on the same plane as the outer peripheral surface of the container body or inwardly.