JP3603667B2 - Heating method for paper container and heating apparatus using the heating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of heating a bonding portion of a paper container and a heating apparatus using the heating method in order to fold and temporarily heat the temporarily folded top or bottom when assembling a rectangular tube-shaped paper container.
[0002]
[Prior art]
Conventionally, gable roof type or brick type paper containers have been used as paper containers for filling liquids such as fruit juice and sake.
[0003]
For example, a gable roof type paper container is first made of a laminated material such as [container outside] polyethylene (PE) / paperboard / PE / aluminum foil (Al) / polyethylene terephthalate film (PET) / PE [container inside]. A blank sheet is formed into a cylindrical shape as shown in FIG. 4 to form a paper container sleeve 20, and the lower adhering portion 15 is bent along a folding line a immediately after being heated in a heating oven, and the heated portion is added. The bottom is molded by pressure bonding.
[0004]
Next, a paper container with a molded bottom is filled with a liquid such as fruit juice, and the upper sticking portion 11 that has been temporarily folded along the fold line b as shown in FIG. 5 is heated in a heating oven and immediately folded and added. A paper container 10 as shown in FIG. 6 was formed by pressure bonding and filling with liquid.
[0005]
And as an apparatus which heats the edge part of the top and bottom of a paper container, there exists a heating oven for upper sticking parts which is illustrated to FIG.
This heating oven is a flat side oven 1A, 1A corresponding to two flat side surfaces of the upper sticking part 11 and a reflection side oven 1B, 1B corresponding to two bent side faces where the upper sticking part 11 is folded. Furthermore, in order to heat the inner wall of the upper sticking part 11 over the entire circumference, it is composed of a hexagonal center oven 1C having a similar shape to the upper sticking part 11 that has been folded.
[0006]
A large number of hot-air blowing holes 2 are staggered in a plurality of stages in the horizontal direction at predetermined portions on the paper container 10 side of the flat side ovens 1A, 1A, the reflection side ovens 1B, 1B, and the center oven 1C. It is provided in a pattern or in parallel.
From these many hot air blowing small holes 2, as shown by arrows in the drawing, hot air is blown to predetermined places on the front and back of the upper sticking portion 11 to be heated.
[0007]
Each heating oven is opened with a sleeve inserted in the groove 3 surrounded by the center oven 1C from the inside, the flat side ovens 1A and 1A from the outside, and the reflection side ovens 1B and 1B. (Bottom) Stopping at the dead point, hot air is blown out from the hot air blowing small hole 2 at a predetermined timing, and the upper sticking portion 11 or the lower sticking portion 15 is heated. As the capacity of the box making machine increases, the cycle time is shortened and the number of heating ovens is increased.
[0008]
That is, for example, there is a method and apparatus for heating a paper container sleeve using a plurality of heating ovens such that the first heating oven for preheating and the second heating oven for main heating are regarded as a pair of heating ovens. It has become mainstream.
[0009]
However, in the heating by blowing hot air, there is a difference in the degree of heating between the portion of the paper container sleeve surface where the direct hot air hits and the portion where it is not, and the thermoplastic resin layer on the surface is partially heated and melted. In other words, there are problems such as the occurrence of heat melting defects or pinholes, and thermocompression bonding defects occur in the bottom and top sealing portions, causing liquid leakage in the liquid paper container.
[0010]
In other words, in the paper laminated material in which a vapor deposited layer of an inorganic compound such as silicon oxide is provided on recent PET and laminated as a gas barrier layer, since a material having good thermal conductivity such as a conventional aluminum foil is not laminated, The heat conduction and diffusion of the thermoplastic resin layer on the surface where hot air is blown by a large number of small holes for blowing hot air is poor, and heat melting is partially poor on the thermoplastic resin layer on the surface where hot air is blown. Locations and pinholes sometimes occurred.
[0011]
One technique for solving this problem is the invention disclosed in Japanese Patent Laid-Open No. 7-24940.
This invention is placed between the inner peripheral heating part of the heating device that heats the inside of the seal part to be joined at the opening end of the paper container before completion of assembly and the heating part of the outer surface that heats the outside of the seal part. Next, by injecting hot air toward the seal portion from a large number of small holes for blowing hot air provided in the inner peripheral heating portion while giving a swing perpendicular to the central axis of the inner peripheral heating portion, A heating method for sealing a paper container in which the hot air is diffused and applied to the seal part and heated on an average, and then the paper container is assembled by crimping and bonding the seal part. The direction of the hot air sprayed from the small holes for blowing hot air is changed by swinging the portion horizontally, and the hot air is diffused so that it does not hit the point of the paper container seal. It is what you do.
[0012]
However, in this invention, since the heating oven is swung in the lateral direction, there is a problem that a structural change of the apparatus is necessary and a large-scale modification is required.
[0013]
[Problems to be solved by the invention]
The present invention relates to a groove surrounding a temporarily folded top or bottom edge of a gable roof type paper container made of a paper laminated material which does not include a metal foil such as an aluminum foil having a thermoplastic resin layer laminated on the surface from inside and outside. Are sequentially inserted into the grooves of a plurality of heating ovens, and hot air is sprayed into and out of the top and bottom of the paper container from the numerous small holes provided facing the grooves of the heating oven. It was made paying attention to the above problems related to the method of heating the thermoplastic resin layer formed in advance on the top and bottom of the paper container, and without changing the structure, the thermoplastic resin layer It is an object of the present invention to provide a method and apparatus for uniformly blowing hot air.
[0014]
[Means for Solving the Problems]
1st invention of this invention consists of a paper laminated material which does not contain metal foil, such as aluminum foil which laminated | stacked the thermoplastic resin layer on the surface, From an upper sticking part, a top part, a wall part, a bottom part, and a lower sticking part The edges of the top and bottom of the gable roof type paper container constructed are inserted into the grooves of a plurality of heating ovens provided with grooves surrounding from the inside and the outside, facing the grooves of the heating oven. In the method of injecting hot air into the top and bottom of the paper container from inside and outside the many small holes provided, and heating the thermoplastic resin layer previously formed on the top and bottom of the paper container with the heat, the gable What is claimed is: 1. A paper container characterized by heating a thermoplastic resin layer with a difference in insertion depth of adjacent top edges and bottom edges of a roof-type paper container into a paper container of an adjacent heating oven It is a heating method.
[0015]
Further, the second invention is made of a paper laminated material not including a metal foil such as an aluminum foil having a thermoplastic resin layer laminated on the surface, and includes an upper sticking portion, a top portion, a wall portion, a bottom portion, and a lower sticking portion. The top and bottom edges of the gable roof type paper container to be temporarily inserted are sequentially inserted into the grooves of a plurality of heating ovens provided with grooves surrounding from inside and outside, and then the upper (lower) of the heating oven. It stops at the dead center, and hot air is sprayed into the top and bottom of the paper container from a number of small holes provided facing the grooves of the heating oven, and the heat is pre-formed on the top and bottom of the paper container. In the heating apparatus for heating the thermoplastic resin layer, the insertion depth of the edge of the top and bottom of the gable roof type paper container into the paper container of the adjacent heating oven is different. Heating the thermoplastic resin layer It is a device.
[0016]
As described above, according to the present invention, the thermoplastic resin is provided with a difference in the insertion depth of the temporarily folded top and bottom edges of the gable roof type paper container into the paper container of the adjacent heating oven. Since the layer is heated, there is no difference in the degree of heating between the portion directly exposed to the hot air on the surface of the sleeve and the portion that is not, uniform heating is performed, and there is no defective portion of heat melting, and uniform heating is performed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by way of examples.
Although not shown, the main body of the paper container heating device according to the present invention comprises a support base, a heat supply unit, a guide cylinder, and an outer cylinder attached so as to rise and lower via an air cylinder. A heating oven 1 is attached to the lower part of the body.
[0018]
Then, as shown in FIG. 3 (a), when the heating oven 1 is lowered, it is located in the vicinity of the portion to be bonded to the portion to be bonded by thermo-compression of the upper adhesive portion of the temporarily folded paper container sleeve 20. It has a structure like this.
A plurality of heating ovens are provided, for example, the first heating oven for preheating and the second heating oven for main heating are paired to heat the top of the sleeve for the paper container, and then thermocompression bonding, Sealed.
[0019]
The heating oven 1 according to the present invention includes flat side ovens 1A and 1A corresponding to the two flat side surfaces of the upper sticking portion 11 of the paper container sleeve 20, and two bent side surfaces where the upper sticking portion 11 is folded. Hexagonal center oven that is similar to the folded upper adhesive part 11 in order to heat the inner side wall of the upper adhesive part 11 over the entire circumference. 1C, each side oven is provided with grooves 3 on both sides of the center oven 1C, and the temporarily folded portion of the paper container sleeve 20 and the portion to be bonded are located at an appropriate interval. It can be done.
[0020]
A plurality of small holes 2 for blowing hot air are provided in parallel in a plurality of stages in the lateral direction on the side surfaces of the flat side ovens 1A, 1A, the reflection side ovens 1B, 1B and the center oven 1C on the groove side.
When the outer cylinder of the heating device is lowered and the top of the paper container sleeve is inserted into the groove 3, hot air blows from the small holes 2 for blowing hot air toward the top, and the thermoplastic resin on the surface of the paper container sleeve The layer is melted and the upper sticking part 11 is sealed. The arrow indicates the direction in which hot air is blown from a small hole for blowing hot air.
[0021]
FIGS. 1 and 2 schematically show the positional relationship when the center ovens 1C of adjacent heating ovens stop at the top (bottom) dead center, and the grooves of the paper container sleeves of the adjacent heating ovens. By varying the insertion depth into the paper, the positional relationship between the small hole for blowing hot air in the first heating oven and the small hole in the adjacent second heating oven is shifted (m = n). Uniformity of heating is improved by reducing the degree of heating of the portion of the inner surface of the container sleeve where the hot air is blown and other portions.
[0022]
The paper container used in this example used a laminated material having the following layer structure.
That is, [the outside of the container] PE (20 μm thickness) / paperboard (310 g / m ² basis weight) / PE (15 μm thickness) / PET (12 μm thickness) / silicon oxide deposited thin film (600 mm) / PE (PE) which is a thermoplastic resin layer 60 μm thickness) [inside the container].
[0023]
The top and bottom of the sealed paper container was cut out in this way, and the occurrence of pinholes was checked with a pinhole check solution, but the occurrence of pinholes from the parts where the crease lines on the top and bottom are concentrated There was nothing.
[0024]
【The invention's effect】
As described above, according to the present invention, by laminating each of the heating ovens in the height direction, a laminate material composed of paper and a thermoplastic resin that does not use metal foil such as aluminum foil with poor thermal conductivity is used. Even in such a case, heating to the paper container sleeve could be made uniform, and as a result, stable paper container molding could be realized.
[0025]
Since the structure of the apparatus itself is the same as the conventional structure, it can be easily developed into an existing apparatus and is inexpensive.
[0026]
Also, when sealing the upper sticking part, if the heating oven is brought close to the liquid level, it will heat up to the part in contact with the liquid inside, and if it is heated too much, it will adversely affect the taste of the liquid However, according to the present invention, since only the lower part is heated only by the first heating oven, the contents are hardly adversely affected.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view illustrating a heating method of the present invention.
FIG. 2 is an explanatory diagram of a main part of FIG.
FIGS. 3A and 3B show an embodiment of a heating oven for top application, where FIG. 3A is an explanatory view seen from the front, and FIG. 3B is a cross-sectional explanatory view taken along line AA ′ of FIG.
FIG. 4 is a perspective explanatory view showing an example of a paper container sleeve used in the present invention.
FIG. 5 is a perspective explanatory view showing a state where a top portion of a paper container sleeve is temporarily folded.
FIG. 6 is a perspective explanatory view showing an example of a paper container used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Heating oven 1A ... Flat side oven 1B ... Reflection side oven 1C ... Center oven 2 ... Hot air blowing small hole 3 ... Groove 10 ... Paper container 11 ... Top sticking part 12 ... Top part 13 ... ··· Wall 14 ··· Bottom portion 15 ··· Lower sticking portion 20 ··· Paper container sleeves a and b ··· Folding lines m and n · · · Position relationship (displacement) between adjacent heating ovens

Claims (2)

It is made of a paper laminated material that does not contain a metal foil with a thermoplastic resin layer laminated on its surface, and it is temporarily folded into a gable roof paper container that consists of an upper adhesive part, a top part, a wall part, a bottom part, and a lower adhesive part The edges of the top and bottom are inserted sequentially into the grooves of a plurality of heating ovens provided with grooves surrounding from inside and outside, and hot air is blown from a large number of small holes provided facing the grooves of the heating oven. In the method of spraying the inside and outside of the top and bottom, and heating the thermoplastic resin layer formed in advance on the top and bottom of the paper container,
The thermoplastic resin layer is heated by making a difference in the insertion depth of the edge of the top and bottom of the gable roof-type paper container into the paper container of the adjacent heating oven. Heating method for paper containers. It is made of a paper laminated material that does not contain a metal foil with a thermoplastic resin layer laminated on its surface, and it is temporarily folded into a gable roof paper container that consists of an upper adhesive part, a top part, a wall part, a bottom part, and a lower adhesive part The top and bottom edges are sequentially inserted into the grooves of a plurality of heating ovens provided with grooves surrounding the inside and outside, and then stopped at the top (bottom) dead center of the heating oven. In a heating device that heats a thermoplastic resin layer formed in advance on the top and bottom of a paper container by injecting hot air into and out of the top and bottom of the paper container through a large number of small holes provided facing the ,
The thermoplastic resin layer is heated by making a difference in the insertion depth of the edge of the top and bottom of the gable roof-type paper container into the paper container of the adjacent heating oven. Paper container heating device.

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