JPH0468218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method of manufacturing a beverage container. More specifically, it is suitable for a simple manufacturing method of a container whose main constituent material is paper (hereinafter referred to as a "paper container"), which is suitable for storing carbonated beverages as the content.

<Conventional examples and their problems> As is well known, beverages such as alcohol, milk, and youth
Today, it is sold commercially in paper containers. This paper container is superior to glass containers, metal containers, plastic containers, etc. in that it is inexpensive and easy to dispose of by incineration or the like.

On the other hand, carbonated drinks such as beer and cola,
Carbonated drinks are still sold in glass, metal, or plastic containers, and there are no carbonated beverages in paper containers.

There are two reasons for this: one is that carbonated beverage containers require extremely high impermeability to carbon dioxide gas, whereas conventional paper containers for alcohol, milk, youth, etc. not meeting the requirements;
The second reason is the internal pressure due to carbon dioxide gas generated from the carbonated beverage inside (2.5Kg/cm2 ^or more at 20℃,
In contrast, the conventional paper containers described above do not have enough ^strength to withstand this internal pressure.

This first problem can be solved by forming a relatively thick carbon dioxide impermeable resin film on the inner surface of the container, but the second problem is serious. In other words, when molding a container using paper as the main constituent material, it is inevitable that the papers will be glued together.
Breakage due to internal pressure mainly occurs at this bonded area.

<Object of the Invention> Therefore, the present invention solves the drawbacks of the above-mentioned conventional examples, and provides adhesives between papers that have sufficient impermeability to carbon dioxide and do not tear due to internal pressure caused by generated carbon dioxide. It is an object of the present invention to provide a simple method for manufacturing a paper container having sections.

<Structure of the Invention> That is, the present invention applies a thermal adhesive to the surface of a paperboard or a laminate containing paperboard, and performs punching, cutting lines, and ruled lines to form (a) a piece of paper at the bottom of a container; (b) ) a large number (n) of container side paper strips connected to the container bottom paper strip and separated from each other by score lines; (c) connected to each of the container side paper strips via arcuate ruled lines; Let y be the length of the arc-shaped ruled line, x be the outline of the opposite side, and f be the distance between the two. When doing so, create a blank consisting of flange paper pieces each having a length that satisfies x=y+2π・f/n...(), mold this blank, and vacuum form the inner surface and flange part. Alternatively, a container is made by fusion-bonding a suitable lid material B to the flange portion of a composite molded product A made by adhering pressure-molded plastic sheets, and the periphery of the opening is a sheet of paper on the side of the container and the flange. This beverage container is characterized in that it is composed of ruled lines between pieces of paper, and the flange paper pieces are folded back to the outside to form a flat flange part.

<Description of Examples> The present invention will be described below with reference to the drawings. Each drawing shows an embodiment of the invention.

FIG. 1 is a sectional view of the constituent material of a blank 1, which is made by applying a thermal adhesive 12 to the surface of a paperboard or a laminate 11 containing paperboard.

Here, as the paperboard or the laminate 11 containing paperboard, any normal paperboard such as normal coated board, Manila board, special paperboard, etc. can be used, and the surface thereof is provided with water resistance. for,
This includes laminated sheets of various plastic films such as polyethylene and polypropylene films, as well as plastic-mixed paper.

The heat-adhesive adhesive 12 described in the present invention includes any adhesive that normally exhibits heat-adhesive properties at about 100°C, such as polyvinyl chloride vinyl acetate copolymer system, ethylene vinyl acetate copolymer system, and acrylic adhesive. It is also possible to use paperboard, and the material may be selected depending on the paperboard or the laminate 11 containing paperboard. The coating method may be any method such as roll coating, gravure coating, or screen coating.

FIG. 2 is a plan view of the blank 1, which has been punched out in the shape shown in the figure, and has cut lines 5 and ruled lines (bending lines) 6. In this drawing, the incision lines 5 are shown as thick solid lines, and the ruled lines 6 are shown as thin broken lines.

This blank 1 includes (a) a container bottom paper piece 2; (b) a large number (n) of container side paper pieces 3 (connected to the container bottom paper piece 2 and separated from each other by score lines 5). In the figure, to distinguish each piece of paper 3,
(Numbers 1, 32, and 33 are marked) (c) A large number (n) of flange paper pieces 4 connected to the container side paper pieces 3 via ruled lines 6 (in the figure, in order to distinguish each paper piece 4, 41, 42, 43
(numbered).

The container bottom paper piece 2 is circular, and the combined portion of the container bottom paper piece 2 and the many container side paper pieces 3 is also circular. Furthermore, the extension of the score line 5 passes through the center of these circles, but the line determining the outer shape of the flange paper piece 4 does not pass through the center of the circles. As will be described later, the flange paper piece 4 forms a flange around the opening when the hemispherical composite molded product A is molded, and the radius of the opening (radius of the hemispherical container)
If r is ny=2πr...() nx=2π(r+f), x=y+2π・f/n
...The lengths x and y are selected so as to satisfy (). here,
n is the number of flange paper pieces 4; It is the length of the arc of the border (the part of the ruled line 6), and f is the distance between the inner arc (ruled line 6) and the outer arc. Note that two of n, x, y, and f can be freely selected, and the other two are determined accordingly.

In addition, the length of the container side paper piece 3, that is, the length of the cut line 5, is 1/4 to 9/20 of the diameter D of the combined part of the container bottom paper piece 2 and the container side paper piece 3. It is desirable that the length is 9/20D >> 1/4D. When the length is <1/4D, the resulting molded product A is unlikely to be hemispherical, whereas when it is >9/20D, the following The preforming mentioned above becomes difficult.

Note that the number of flange paper pieces 4, that is, the number n of container side paper pieces 3, is preferably 12≦n≦16, and when n<12, the obtained molded product A is difficult to become hemispherical, and n >16, preforming becomes difficult.

This blank 1 is inserted into a mold 7 such as a mold of a vacuum forming machine with the adhesive layer 12 inside, and is preformed into the shape of a composite molded product A to be described later. The plan view of FIG. 3a and the sectional view of FIG. 3b show the state at this time. Figure 4 shows the container side paper pieces 31, 32, 33 and the flange paper piece 4 in Figure 3.
1, 42, and 43; FIG. That is, the flange paper pieces 41, 42, 4
3 is folded back to the outside along the ruled line 6, and these pieces of paper 41, 42, 43 do not overlap each other, and ultimately there is no gap between them. On the other hand, the container side paper pieces 31, 3
2 and 33 partially overlap the adjacent container side paper pieces. In FIG. 4, the paper strip 3 on the side of the container
The outline of the paper piece 31 which is overlapped on the outside of the paper piece 2 and cannot be seen (corresponding to the cut line 5 of the blank) and the outline of the paper piece 32 which is overlapped on the outside of the paper piece 33 and cannot be seen are shown by thick broken lines. All of the other container side paper pieces 3 are in the same state.

This preforming does not necessarily have to be the same shape as the final composite molded product A, but may be molded into a shape close to this.

Further, this preforming may be performed at the same time as the blank 1 is inserted into the mold 7, or may be preformed before insertion and then inserted into the mold 7.

After that, as shown in FIG. 5, a vacuum-formable plastic sheet 8 is held by a clamp 9, and the entire plastic sheet 8 and blank 1 are heated by a heater 10, and the plastic sheet is placed on the top of the blank 1 and the mold 7. 8 are stacked on top of each other, and suction is applied from the vacuum suction hole 71 of the mold 7. Instead of suctioning from the mold 7 side, gas pressure may be applied from the plastic sheet 8 side.

The plastic sheet 8 used here is
A carbon dioxide impermeable sheet with a thickness of 300 to 2000μ made by laminating a polyester resin sheet, polyvinylidene chloride resin sheet, polyacrylonitrile resin sheet, polycarbonate sheet, nylon sheet, vinylon sheet, or a combination of these sheets. can be used.

Figure 6 shows the plastic sheet 8
This figure shows the state immediately after the plastic sheet 8 is vacuum-formed, and the three-dimensional paper blank 1 having an adhesive layer on the inside is molded by heating and applying vacuum to the mold 7.
It is closely molded on the outside of the mold 7. That is, the three-dimensional paper blank 1 is tightly attached to the plastic sheet 8 due to heat pressure during molding, and the blank 1
In addition to being bonded by the adhesive 12 on the surface, as can be seen in FIGS. 3 and 4, the areas where the paper strips 3 on the side of the container overlap each other are also bonded by the adhesive 12 activated by heat. , these are glued together.

Thereafter, this is taken out from the mold 7 and the surrounding plastic sheet 8 is removed to obtain a composite molded product A which is to become the container body.

As shown in the front view of FIG. 7, this composite molded product A is a hemispherical or approximately hemispherical container having a flange portion 4 around the opening, and this flange portion 4 has a flange paper piece 4 of the blank 1 on the outside. The plastic sheets 8 are folded back so that they are lined up without overlapping each other or with any gaps between them, and the plastic sheets 8 are laminated on top of them, so they are completely flat with no unevenness. Furthermore, the radius r of this opening satisfies 2πr=ny.

After this composite molded product A is filled with contents as necessary, a suitable lid material B is placed on top of the composite molded product A and fused and bonded at the flange portion 4 to obtain a beverage container.

The lid material B may be of any material, but in consideration of the internal pressure due to the carbonated beverage content, it is preferable that the lid material B is also hemispherical or approximately hemispherical, like the composite molded product A. Figure 8 shows composite molded product A.
In this example, the lid material B is a molded product provided with an inflow port 20 for contents.

A cross-sectional view of this lid material B is shown in FIG.
is attached from the inside into a hole punched in the bottom of the composite molded product A, and fused to the plastic sheet 8. Preferably, the inlet 20 is made of the same material as the plastic sheet 8.

Figure 10 shows the composite molded product A obtained in this way.
A beverage container according to the present invention can be obtained by attaching a cap 30 to the lid member B by fusion-bonding the flange portions 4 facing each other.

As a method for welding and joining these two parts at their flange portions, a rotational friction heat welding method (spin welding method), an ultrasonic welding method, a high frequency welding method, a heat sealing method, etc. can be used. According to the inventor's study, the spin weld method was found to be good.

The case where a hemispherical or approximately hemispherical molded product having a flange portion is used as the composite molded product A and the lid material B has been explained above as an example. In this case, the resulting container is a perfect sphere as shown in FIG. The container is shaped like a cylindrical container or has a substantially perfect spherical shape, and can minimize the stress exerted on the container wall by the internal pressure of the carbonated beverage content. Note that the container according to the present invention is not limited to this shape, and may be, for example, an oblong sphere as shown in FIGS. 11a and 11b.

<Effects of the Invention> In any case, the container of the present invention has a completely flat flange and no gap, so
The lid material B stacked on top of the lid material B is in close contact with the lid material B so that no gap is formed, and the composite molded product A and the lid material B will not be destroyed by the internal pressure caused by the carbonated beverage content. Further, since the flange portion is completely flat, it is advantageous when the composite molded product A and the lid material B are fused and joined by the spin weld method.

<Example 1> (1) On the back of a coated ball with a basis weight of 310 g/ ^m2 ,
AD37P66 varnish (manufactured by Toyo Ink Mfg. Co., Ltd.), which is an ethylene/vinyl acetate copolymer heat-sensitive adhesive, was applied wet at 20 g/m ² using a bar coating method and dried.

(2) Next, punch out this paperboard with a cutting die having the pattern shown in Figure 2, and as shown in Figure 3, fold the ruled lines and pull up the pieces of paper around the container to create some paper curls. was attached to obtain a temporary three-dimensional blank.

(3) Next, this three-dimensional blank was inserted into a hemispherical mold as shown in FIG.

(4) On the other hand, unstretched polyester sheet 500μ (Teijin: C-PET) and unstretched polyacrylonitrile sheet 500μ (Mitsui Toatsu: Zekron Sheet)
The sheet laminated using the dry lamination method is sandwiched between the clamps of the vacuum forming machine shown in Figure 5 with the polyester sheet side facing up, and heated to 140 mm using a heater.
After heating at ℃ for 10 seconds, it was brought into close contact with the mold into which the three-dimensional blank was inserted, and then suction was applied.
After molding, the flange portion was cut to a certain size to obtain a composite molded product A consisting of paper/acrylonitrile sheet/polyester sheet as shown in FIG.

(5) On the other hand, after punching out the bottom of the composite molded product obtained in (4) and making certain holes, an inlet made of polyester resin made by injection molding is shown in Figures 8 and 9. The lid material B shown in FIG. 8 was obtained by inserting it in the same manner as described above and fusing it by a spin welding method.

(6) Next, as shown in Fig. 10, the composite molded product A and the lid material B are faced at the flange part, fusion-bonded using the spin weld method, and a cap is attached to the inlet and outlet to ensure pressure resistance. A beverage container with good barrier properties was also obtained.

When the pressure resistance of the obtained container was examined, it was found to be 5 kg/
Good results were obtained without deformation or rupture even when an internal pressure of cm ² or more was applied.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a sectional view of the blank, FIG. 2 is a plan view of the blank, and FIGS. 3 a and b are plan views of the blank after it has been preformed and inserted into a mold. and a sectional view, FIG. 4 is an explanatory diagram for explaining the state of the container side paper piece and flange paper piece in FIG. 3, FIG. 5 is a sectional view during molding, and FIG. 6 is a sectional view immediately after molding. , FIG. 7 is a front view of the composite molded product A obtained by molding, FIG. 8 is a front view of the lid material, FIG. 9 is a sectional view of the lid material, FIG. 10 is a front view of the beverage container, and FIG. The figure is a front view of a beverage container of another embodiment. 1... Blanks, 11... Paperboard or a laminate containing paperboard, 12... Adhesive, 2... Container bottom paper piece, 3, 31, 32, 33... Container side paper piece,
4, 41, 42, 43...flange paper piece or flange, 5...cut line, 6...ruled line (bending line), 7...mold, 71...vacuum suction hole, 8...plastic sheet, 9 ... Clamp, 10 ... Heater, 20 ... Outlet and inlet, 30 ... Cap.

Claims (1)

[Scope of Claims] 1. A thermally adhesive adhesive is applied to the surface of paperboard or a laminate containing paperboard, and punching and cutting lines and ruled lines are performed to form (a) a piece of paper at the bottom of the container, (b) the bottom of the container. A large number (n) of container side paper strips connected to the paper strips and separated from each other by score lines; (c) connected to each of the container side paper strips through arc-shaped ruled lines, When there are a large number (n) of flanged paper pieces in which the outline of the opposite side of the ruled line is a circular arc, the length of the arc-shaped ruled line is y, the outline of the opposite side is x, and the distance between the two is f, Create a blank consisting of flanged paper pieces each having a length that satisfies the following: The container is made by fusion-bonding a suitable lid material B to the flange part of a composite molded product A made by gluing together plastic sheets, and the periphery of the opening is the container side paper piece and the flange paper piece. 1. A beverage container comprising ruled lines in between, and a flange paper piece folded back to the outside to form a flat flange part.