JP2004090928A - Insulated paper container - Google Patents

Abstract

An object of the present invention is to provide a paper container exhibiting excellent heat insulating properties, which can be manufactured inexpensively and easily in spite of having a double structure, and can be continuously gripped with bare hands even when hot water is poured.
A container body includes a body having an edge at an upper end, a bottom plate locked near a lower end of an inner wall surface of the body, and mounted on an outer wall surface side of the body of the container. In the heat insulating container made of paper comprising a cylindrical body winding, the body of the container body has a step formed by radially expanding a portion closer to the upper part in a radially outward direction. A first sidewall portion up to an upper end has a first taper, a second sidewall portion from the step to the lower end has a second taper, and the first taper is the second taper. Or the same as, or different from, the cylindrical bobbin has a taper that is substantially the same as the first taper of the first side wall portion, so that when the cylindrical bobbin is mounted on the body portion A part of the inner wall surface of the cylindrical bobbin closely adheres to the outer wall surface of the first side wall portion of the trunk portion;
A heat-insulating paper container characterized by the above-mentioned.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat insulating paper container. More specifically, the present invention relates to a heat insulating member joined on an outer wall surface of a container body to form an insulating gap between the container outer wall surface and an inner wall surface of the container member. The present invention relates to a paper container.
[0002]
[Prior art]
Conventionally, several types of heat-insulating containers for filling a high-temperature liquid have been put to practical use. For example, a foamed polystyrene insulated container has been used for such a purpose. This is produced by casting a foamed polystyrene material into a mold, applying heat and pressure to foam the material, and removing the molded container from the mold. The heat-insulating container thus obtained is very excellent in terms of heat insulation. However, it is by no means economical in terms of manufacturing costs. In addition, it has been reported that when boiling water is injected into a foamed polystyrene container, a trace amount of environmental hormone is eluted from the container body, which has an adverse effect on the human body. Moreover, it is a container that needs to be reexamined in terms of saving petroleum resources or incinerating waste. Furthermore, since the outer surface of the heat insulating container made of Styrofoam is not smooth, there is a drawback that printing suitability is poor.
[0003]
In particular, various paper containers have been proposed and used as containers for instant noodles or instant soups in terms of disposability. As a kind of the heat-insulating paper container used for such a purpose, there is a special heat-insulating container (Japanese Patent No. 3014629) having a heat-insulating layer formed by laminating a low-melting thermoplastic synthetic resin film on the outer wall surface and foaming by heating. Japanese Patent Application Laid-Open No. 11-268781), a heat insulating container in which a paper bobbin is closely attached to the outer wall surface of such a special heat insulating container (see Japanese Patent Application Laid-Open No. H11-268781), and a container having a double or triple structure of paper alone. It is a target.
[0004]
The double cup made of paper is described in, for example, Japanese Patent No. 3291262, Japanese Patent Application Laid-Open No. 2000-103476, Japanese Patent Application Laid-Open No. 2000-103377, and Japanese Patent Application Laid-Open No. 2000-128253. In these double cups, a paper bobbin is arranged on the outer surface of the paper container main body, and a gap is provided between the outer surface of the container main body and the bobbin so as to exhibit a heat insulating effect. However, when hot water of 90 ° C. or more is actually poured into the container body and the body winding is grasped with bare hands, it is too hot to hold the container.
[0005]
Although the triple cup is excellent in heat insulation, the manufacturing process is complicated, the productivity is limited, and the cost is high. Therefore, there is a strong demand for the development of a heat-insulating paper container which can reduce the cost more than a triple cup and has heat insulation similar to that of a triple cup.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a paper container exhibiting excellent heat insulating properties which can be easily manufactured at a low cost and easily even when hot water is poured, in spite of having a double structure, and which can be continuously gripped with bare hands. It is to provide.
[0007]
[Means for Solving the Problems]
The object is to provide a container body including a trunk having an edge at an upper end, a bottom plate portion locked near a lower end of an inner wall surface of the trunk, and a container body attached to an outer wall surface of the trunk of the container body. In a paper heat insulation container consisting of
The body of the container body has a step formed by radially expanding the upper part thereof radially outward, and a first side wall part from the step to the upper end has a first taper. A second side wall portion from the step to the lower end has a second taper, and the first taper is the same as or different from the second taper,
The cylindrical bobbin has substantially the same taper as the first taper of the first side wall portion, whereby when the cylindrical bobbin is mounted on the body, the inner wall surface of the cylindrical bobbin A part of the body adheres to the outer wall surface of the first side wall portion of the body,
The problem is solved by a heat-insulating paper container.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the heat-insulating paper container of the present invention will be specifically described with reference to the drawings.
[0009]
FIG. 1 is a partially enlarged sectional view of an example of the heat insulating paper container of the present invention. As shown in FIG. 1, the heat-insulating paper container 1 of the present invention consists essentially of a container body 10 and a cylindrical bobbin 30. The container body 10 includes a body 12 and a bottom plate 14. Both the body 12 and the bottom plate 14 are formed of paper 16, but since the inside of the container body 1 is filled with liquid, both the body 12 and the bottom plate 14 have a thermoplastic synthetic resin on their inner wall surfaces. A resin film 18 (for example, polyethylene, polystyrene, nylon, polypropylene, or polyethylene terephthalate) is laminated. Instead of a thermoplastic synthetic resin film, an aluminum foil can be laminated. Such liquid-permeable paper cups per se are well known to those skilled in the art. A heat insulating gap 40 is formed between the container body 10 and the cylindrical body winding 30.
[0010]
As shown in FIG. 1, at the upper end of the body portion 12 of the container body 10, there is an edge portion 3 formed by curling the upper part of the body member toward the outside of the container. Furthermore, a step 9 is formed by radially expanding the upper portion of the body 12 radially outward, and the first side wall 5 from the step to the upper end has a first taper. And a second side wall portion 7 from the step to the lower end has a second taper. The first and second tapers can be different or can be the same.
[0011]
The cylindrical body winding 30 has a taper that is substantially the same as the first side wall portion 5 of the body 12 of the container body 10. Further, it is preferable that the inner diameter of the upper end portion of the body winding 30 is substantially the same as or slightly smaller than the upper outer diameter of the first side wall portion 5. Accordingly, when the body winding 30 is mounted on the body 12 such that the upper end 32 of the body winding 30 is brought into contact with the lower end of the curled portion 3 of the body 12, the inner wall surface of the upper part of the body winding 30 is The first side wall portion 5 can be in close contact with the outer wall surface without any gap. If necessary, an adhesive may be applied to the contact interface between the cylindrical body winding 30 and the first side wall 5 of the container body 10 to further increase the bonding strength between the two members. On the other hand, the inner diameter of the lower end 34 of the body winding 30 is preferably substantially the same as or slightly smaller than the outer diameter of the lower end 20 of the body 12. Similarly to the above, if necessary, an adhesive is applied to the contact interface between the lower end portion 34 of the cylindrical body winding 30 and the second side wall portion 7 of the container body 10 to further increase the bonding strength between the two members. You can also. With such a configuration, as shown in FIG. 1, the body winding 30 can be firmly attached to the outer wall surface side of the container body 12. When the inner diameter of the lower end 34 of the body winding 30 is larger than the outer diameter of the lower end 20 of the container body 12, the lower end 34 of the body winding 30 and the lower end 20 of the body 12 of the container body 10 do not adhere to each other. , It may be "wobbled" and impair the aesthetics. The height of the body winding 30 is selected such that the lower end portion 34 of the body winding 30 and the lower end portion 20 of the body portion 12 are "surface-matched" when the body winding 30 is mounted and fixed to the body portion 12. However, the lower end 34 of the body winding 30 may be above the lower end 20 of the body 12, that is, so-called “small”.
[0012]
The cylindrical bobbin 30 is essentially made of paper. As the base paper constituting the cylindrical body winding 30, ordinary cardboard or the like generated from virgin pulp can be used, but it contains at least 80% of used paper and has a basis weight of 270 g / cm ^{2 to} 500 g / cm ^2. It is preferred to use a coated cardboard in the range of Use of recycled paper having such a high used paper content is not only preferable from the viewpoint of resource recycling, but also can provide higher rigidity and higher heat insulation as compared with virgin pulp paper having the same basis weight. Such recycled paper is also excellent in terms of print aesthetics. However, if the basis weight is less than 270 g / cm ² , sufficient rigidity as the body winding is not exhibited, and when the container 1 is grasped by hand, the body winding 30 is greatly dented, which is not preferable. On the other hand, if the basis weight is more than 500 g / cm ^2, it is uneconomical because not only the rigidity required for the body winding is exceeded, but also the workability is significantly reduced.
[0013]
As the base paper constituting the cylindrical body winding 30, ordinary cardboard or the like generated from virgin pulp can be used, but it contains at least 80% of used paper and has a basis weight of 270 g / cm ^{2 to} 500 g / cm ^2. It is preferred to use a coated cardboard in the range of Use of recycled paper having such a high used paper content is not only preferable from the viewpoint of resource recycling, but also can provide higher rigidity and higher heat insulation as compared with virgin pulp paper having the same basis weight. Such recycled paper is also excellent in terms of print aesthetics. However, if the basis weight is less than 270 g / cm ² , sufficient rigidity as the body winding is not exhibited, and when the container 1 is grasped by hand, the body winding 30 is greatly dented, which is not preferable. On the other hand, if the basis weight is more than 500 g / cm ^2, it is uneconomical because not only the rigidity required for the body winding is exceeded, but also the workability is significantly reduced.
[0014]
As described above, by attaching and fixing the body winding 30 to the outer wall surface of the first side wall 5 of the body 12 of the container body 10, as shown in FIG. A space 40 is formed between the outer wall surface and the inner wall surface of the cylindrical bobbin 30, and the presence of the space 40 imparts a high degree of heat insulation to the container 1 of the present invention.
[0015]
The container body 10 can be easily assembled by a common cup manufacturing apparatus. For example, first, a container body base paper is fed from roll paper, and a thermoplastic synthetic resin film such as polyethylene is laminated on one side of the base paper. A thermoplastic synthetic resin film is similarly laminated on one side of the base paper. A blank for the container body is punched from the base paper for the container body, and a blank for the bottom plate is punched from the base paper for the base plate. In addition to the container body blank, a bottom plate blank can also be punched from the container body base paper. Using these blanks, in a conventional cup molding machine, the container body blank is oriented so that the film laminated surface faces the inside of the container, and the bottom plate is oriented so that the film laminated surface faces the inside of the container. assemble.
[0016]
The paper material forming the container body 10 is not particularly limited. Since the container body 10 is on the inside and not directly on the side held by a human hand, it is not necessary to use fresh and strong paper. As a general indication, the container body preferably paper having a basis weight in the range of ^{150g / m 2 ~350g / m 2} . Since the step portion 9 of the body portion 12 is formed by the "ironing method", it is not preferable in terms of processing workability because it is difficult to form the paper with a very strong paper. Therefore, it is preferable to use low-density, somewhat soft, stretchable paper for the container body, especially for the body.
[0017]
FIG. 2 is a schematic diagram illustrating an example of a processing method for forming the step 9 above the body 12 of the container body 10. As shown in FIG. 2A, the container body 10 in which the body 12 and the bottom plate 14 are integrally joined and the container edge is molded is inserted into the female mold 90. An upper portion of the female mold 90 is formed with a first inner wall portion 94a which expands radially outward with a first taper. On the other hand, a male mold 92 fitted into the female mold 90 is disposed above the female mold 90. The male mold 92 is configured to be rotatable and to be able to move up and down in the vertical direction. A lower portion of the male mold 92 is formed with an inclined outer wall portion 94b corresponding to the first inner wall portion 94a of the female mold 90. As shown in FIG. 2B, the male mold 92 is lowered, and the container body 12 is rotated while being pressed against the female mold 90, thereby "ironing" the upper part of the container body 12. A polyethylene film (not shown) or the like is laminated on the inner wall surface side of the container body 12, but basically the polyethylene film has a higher elongation rate than paper, so if there is no excess, It is not cut by "ironing" processing. However, in general, great care should be taken to perform a "ironing" process so that the polyethylene film or the like does not break. When the “ironing” process is completed, the male mold 92 is raised, and the container body 10 having the step 9 above the body 12 is taken out from the female mold 90 as shown in FIG.
[0018]
FIG. 3 is a schematic configuration diagram of an example of the apparatus for manufacturing a heat-insulating paper container according to the present invention. A plurality of (eight in the embodiment of FIG. 6) cup-shaped rotatable molds 71 are provided on the outer peripheral surface of the mandrel 70 that rotates intermittently (revolves). A paper container main body 10 formed in advance using a conventional container manufacturing method and apparatus is first pneumatically fed by a tube 72 and attached to a mold 71. Although not shown, each mold is provided with both an air blowing hole and an air suction hole, and the container body is fixed to the mold 71 by suction pressure until moving to the next station. . Thereafter, if necessary, an adhesive is applied to a predetermined portion of the outer wall surface of the container main body 10 (for example, the outer wall surface near the first side wall portion 5 and / or the lower end portion 20 in FIG. 1) using an adhesive applicator 80. Is applied. As the adhesive, any known and commonly used adhesive such as pressure-sensitive or heat-sensitive can be appropriately selected and used. Adhesives that can be used for such purposes include, for example, aqueous adhesives composed of emulsions of vinyl acetate, ethylene / vinyl acetate copolymer, vinyl acetate / acrylic copolymer, other acrylic copolymers, and other vinyl copolymers. Coating methods other than those illustrated may also be used. Such application methods are known to those skilled in the art.
[0019]
For example, the cylindrical body winding 30 supplies the blanks 82 one by one from the blank stocker 81 to the body winding forming machine 83, winds the blanks 82 around the mold of the body winding forming machine 83, and applies an adhesive to one of the linear pieces of the blank. It can be made by applying and overlapping both linear pieces and joining them to form a side seam. Since the cylindrical body winding 30 does not have a bottom plate, it cannot be fed by air. Therefore, the suction arm 84 is used to suck the outer peripheral side wall of the body winding to convey it. The body winding blank can be supplied to the body winding forming machine 83 while being punched from the base paper.
[0020]
The cylindrical body winding 30 formed by the body winding forming machine 83 is sucked by the suction arm 84 and put on the outside of the body of the container body 10. Since the suction arm 84 itself is a transport means of the cylindrical body winding, the cylindrical body winding 30 covered on the outside of the container body 10 cannot reach the edge of the container body. For this reason, when the cylindrical body winding 30 is put on the outside of the container body 10, the mandrel 70 is intermittently fed, the bottomed pressing jig 85 is put on the outside of the cylindrical body winding 30, and this pressing jig 85 is put on the mandrel 70. By pressing the cylindrical body winding 30 downward, the cylindrical body winding 30 is brought into contact with the lower end surface of the rim portion 3 of the container body 10, and the cylindrical body winding 30 is brought into close contact with the outer wall surface of the first side wall 5 of the container body 10. If an adhesive is used in a predetermined portion of the container body 10, the container body and the cylindrical bobbin are bonded via the adhesive. Thereafter, the pressing jig 85 is pulled out, and the heat insulating paper container 1 of the present invention is completed. Finally, air is injected from the air outlet of the mold, the completed container 1 is released from the mold, and further suction-conveyed by the suction conveyance tube 86 to be accumulated in the product stocker (not shown). Instead of using the suction / conveyance tube 86, the stock can be performed on the spot released from the mold.
[0021]
【Example】
Hereinafter, the effect of the heat insulating paper container of the present invention will be demonstrated by specific examples.
[0022]
Example 1
The heat insulating paper container of the present invention was manufactured according to the procedure shown in FIGS. The manufactured container has a shape substantially as shown in FIG. This container has a capacity of 250 ml, a paper having a basis weight of 250 g / m ² (virgin pulp 100%, a density of 0.84 g / cm ³ ) and a cylindrical body winding having a basis weight of 310 g / m 2. Paper No. ² (used paper content 80%, density 0.83 g / cm ³ ) was used. On the paper for the container body, a polyethylene film having a thickness of 20 μm was laminated on one side.
[0023]
Comparative Example 1
A container body was produced using the same paper as in Example 1 having a basis weight of 250 g / m ² (virgin pulp 100%, density 0.84 g / cm ³ ). The container body was not provided with a cylindrical body winding.
[0024]
Heat insulation test The container of the present invention and the control container were filled with hot water at 95 ° C until the ninth minute of the container capacity, and the heat insulation effect was measured. The temperature was measured in a room at 23 ° C. and a relative humidity of 50% in accordance with the standard defined in JIS P8111. The temperature measurement on the outer surface of the container (that is, the outer surface of the body winding) was performed at one-third of the position after dividing the entire height of the container into three equal parts. FIG. 4 shows the measurement results. (A) is the measurement result in the container of the present invention, and (b) is the measurement result in the control container. As is clear from the results shown in the drawing, the paper container of the comparative example is at about 80 ° C. 30 seconds after the injection of hot water, and it is impossible to grasp the container body with bare hands, The heat-insulating paper container of the present invention is at about 65 ° C., and the container body can be grasped with bare hands. After 5 minutes, the temperature of the paper container of the comparative example is about 75 ° C., and it is still difficult to grasp the container body with bare hands, whereas the heat-insulating paper container of the present invention is about 61 ° C. ° C, and the container body can be more easily grasped with bare hands. Therefore, from these experimental data, it can be seen that the container of the present invention, in which a cylindrical bobbin is disposed on the outer surface of the container main body and a heat insulating gap is formed between the container main body and the cylindrical bobbin, exhibits excellent heat insulating properties. It can be understood.
[0025]
Next, according to the method specified in JIS P8111, the cup rigidity (strength against crushing when the cup is pushed from the side) was measured in a room at 23 ° C. and a relative humidity of 50%. The cup stiffness of only the container body having no cylindrical body winding was 210 gf, whereas the cup stiffness of the container of the present invention was 500 gf. As is evident from these results, the container of the present invention has about 2.4 times higher strength as a whole container including a cylindrical body winding than a container composed of only a normal container body.
[0026]
【The invention's effect】
As described above, according to the present invention, in spite of the double structure, it can be manufactured at low cost and easily, and even when hot water is poured, it can be continuously gripped with bare hands immediately after injection. A paper container showing excellent heat insulating properties is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an example of a heat insulating paper container of the present invention.
2A and 2B are schematic cross-sectional views illustrating an example of a processing step when forming a step portion 9 near an upper portion of a container main body shown in FIG. 1; FIG. FIG. 4B shows a state in which a rotatable male mold is about to be fitted into the mold, and FIG. 4B shows a state in which the upper part of the container body in the female mold is “ironed” while the male mold rotates. 9 shows a state in which the “ironing” process is completed and the male mold is separated from the female mold.
FIG. 3 is a schematic view showing an example of the apparatus for manufacturing a heat insulating paper container of the present invention.
FIG. 4 is a characteristic diagram showing the heat insulating effect of the heat-insulating paper container of the example of the present invention and the paper container of the comparative example.
[Explanation of symbols]
1 Heat-insulating paper container 5 of the present invention 5 First side wall 7 Second side wall 9 Step 10 Container body 12 Body 14 Bottom plate 16 Paper 18 Polyethylene laminated film 20 Body lower end 30 Cylindrical body winding 32 Upper end of cylindrical winding 34 Lower end of cylindrical winding 40 Insulated gap

Claims (7)

A container body including a body having an edge at an upper end, and a bottom plate locked near a lower end of an inner wall surface of the body, and a cylindrical body winding mounted on an outer wall surface side of the body of the container body In a paper insulation container consisting of
The body of the container body has a step formed by radially expanding the upper part thereof radially outward, and a first side wall part from the step to the upper end has a first taper. A second side wall portion from the step to the lower end has a second taper, and the first taper is the same as or different from the second taper,
The cylindrical bobbin has substantially the same taper as the first taper of the first side wall portion, whereby when the cylindrical bobbin is mounted on the body, the inner wall surface of the cylindrical bobbin A part of the body closely adheres to the outer wall surface of the first side wall portion of the trunk portion,
A heat-insulating paper container characterized by the above-mentioned. It said tubular wrapping is waste paper content of 80% or more, the basis weight is formed from recycled paper in the range of ^{270g / cm 2 ~500g / cm 2} ,
The heat-insulating paper container according to claim 11, characterized in that: The upper end of the cylindrical body winding contacts the lower part of the rim of the container body, and the lower end of the cylindrical body winding is flush with the lower end of the container body.
The heat-insulating paper container according to claim 1 or 2, wherein: The upper end portion of the cylindrical body winding contacts the lower part of the rim of the container body, and the lower end of the cylindrical body winding is located above the lower end of the container body.
The heat-insulating paper container according to claim 1 or 2, wherein: An upper inner wall surface of the cylindrical bobbin is adhesively bonded to a first side wall portion of the container body.
The heat-insulating paper container according to claim 1, 2 or 3. The lower end inner wall surface of the cylindrical body winding is intermittently adhesively bonded to the lower end outer wall surface of the container main body,
The heat-insulating paper container according to claim 5, wherein: A lower end inner wall surface of the cylindrical body winding is continuously adhesively bonded to a lower end outer wall surface of the container main body,
The heat-insulating paper container according to claim 5, wherein:

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