JP4090563B2 - Heat insulating paper cup - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-insulating paper cup used as a container for instant foods such as ramen, soup and miso soup.
[0002]
[Prior art]
Conventionally, as a heat-insulating container used as a container for instant foods such as ramen, soup, miso soup, etc., a synthetic resin having foaming properties, particularly those made of expanded polystyrene resin as raw materials, are often used. . Also, as a paper cup with heat insulation, a paper cup with a corrugated shape made of paper around the entire circumference of the paper cup or a double structure with an inner side and an outer side with a space between two layers In addition, there is a foamed polyethylene resin layer on the surface of a paper cup using a material in which both surfaces of paper are laminated with a polyethylene resin layer.
[0003]
[Problems to be solved by the invention]
However, in the container having the above heat insulating property, the container made of expanded polystyrene resin is manufactured by molding a resin to which a foaming agent is added and is excellent in heat insulating property, but is difficult to treat as waste after use. There is a problem in terms of environmental response. In addition, there are disadvantages such as low surface smoothness and poor printability.
[0004]
In addition, paper cups with corrugated paper around the entire circumference are excellent in terms of heat insulation and environmental friendliness, but in manufacturing, the process of making the corrugated part corrugated and winding it around the body is required However, there are technical difficulties and the cost is high.
[0005]
These heat-insulating cups have heat-insulating properties, printability, easy disposal as waste after use, simple manufacturing processes, and low cost. It is a paper cup made by foaming. This foamed paper cup is applied to a method for producing a concavo-convex pattern by heating a polyethylene resin processed paper and foaming a polyethylene resin layer on the surface by the vapor pressure of water contained in the paper, as disclosed in Japanese Patent Publication No. 48-32283. Is. Japanese Patent Application Laid-Open No. 57-110439 discloses a paper cup as a paper container comprising a barrel member and a bottom plate member in which a foamed layer of a thermoplastic synthetic resin film is coated or laminated on one side wall surface of the barrel member. Has been. Furthermore, in JP-A-5-50536 and JP-A-7-232774, as a heat-insulating paper container having a printing layer made of colored ink between a polyolefin-based resin layer and a base material layer mainly composed of paper, A manufacturing method is disclosed in which a thick foam layer is provided at the printed portion.
[0006]
However, conventional foamed paper cups cannot be said to have sufficient heat insulation properties, and beverage paper cups are good, but not particularly in instant food paper cups. In addition, instant food paper cups generally require a large capacity and sufficient shape retention during handling. Single-layer foamed paper cups that do not have a double structure have sufficient strength. Absent. Furthermore, there is a drawback that printed pictures and characters are damaged by the foamed surface layer.
On the other hand, the present invention provides a heat insulating paper cup that has sufficient heat insulating properties, has sufficient shape retention during handling, has an appearance printing effect, and can be manufactured at a relatively low cost.
[0007]
[Means for Solving the Problems]
As a result of studying to solve the above-described problems, the present invention is a paper cup that includes a paper cup body that includes a body portion and a bottom portion, and a paper winding portion that is fitted to the outer periphery of the body portion of the paper cup body. The paper cup body is formed by heating and evaporating the moisture contained in the paper by the thermoplastic resin (surface) in order from at least the outer surface side , foaming layer by the vapor pressure , base material layer mainly composed of paper and heat The paper winding portion includes a thermoplastic resin (front surface), a base material layer mainly composed of paper, and a thermoplastic resin layer (back surface) contained in the paper in order from at least the outer surface side. The gist of the present invention is a heat insulating paper cup provided with a foamed layer obtained by evaporating water to be heated and evaporating by the vapor pressure .
[0008]
Further, the foam layer of the paper cup body may be formed such that a part of the foam layer protrudes from the other part. In this embodiment, when the paper cup body and the paper winding part are fitted, the paper cup A heat insulating paper cup having a high heat insulating effect by forming a gap between the body portion of the main body and the paper winding portion can be obtained. In this case, in the trunk portion of the paper cup body, a printing layer is partially provided between the foam layer and the base material layer, and the convex portion is formed in the portion of the foam layer that overlaps the print layer. To do. And the said convex part was continuously formed in the outer peripheral direction of the trunk | drum of the said paper cup main body, it was formed in the up-down direction of the trunk | drum of the said paper cup main body, and the number of the said convex parts is plurality. It is characterized by that.
[0009]
According to the present invention, the paper cup body also has heat insulation, and the paper winding part having heat insulation has a double structure, so that heat insulation is sufficient, and also in terms of shape retention during handling It is possible to obtain a heat-insulating paper cup that has sufficient strength, has an appearance printing effect, and can be manufactured at a relatively low cost.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings.
As shown in FIG. 1, the heat insulating paper cup 1 according to the present invention includes a paper cup main body 2 and a paper winding portion 5, and is formed by winding or fitting the paper winding portion 5 around the outer periphery of the paper cup main body barrel portion 3. . Further, as shown in FIG. 2, the paper cup main body 2 includes a paper cup main body barrel 3 and a paper cup main body bottom 4. Further, as shown in FIG. 3, the paper cup main body barrel 3 may be provided with a convex portion 6. By providing the convex portion 6, when the paper cup main body 3 and the paper winding portion 5 are fitted, an air layer gap 7 is formed between the paper cup main body 3 and the paper winding portion 5. An excellent heat insulating paper cup 2 is obtained.
[0011]
Next, the material configuration will be described in detail. As shown in FIG. 4, the material configuration of the paper cup body trunk 3 is based on a base layer 11 mainly composed of paper, and a foam layer 12 in which a thermoplastic resin layer (surface) is foamed on the surface side, It is covered. A thermoplastic resin layer (back surface) 13 is provided on the back surface side. An aluminum foil layer or the like may be provided between the paper layer 11 and the thermoplastic resin layer (back surface) 13 in order to improve barrier properties.
[0012]
The base material layer 11 mainly composed of paper is the main strength material of the heat insulating paper cup 1 of the present invention, and it is preferable to use a base paper suitable for paper cup molding. The basis weight is preferably in the range of 100 to 400 g / m ² in the production of a paper cup. Further, the moisture content of the paper is important, and the range of 3 to 10% is preferable, and the range of 5 to 8% is more preferable. When the moisture content in the paper is evaporated and the foam layer 12 is formed by foaming the thermoplastic resin layer on the surface with the force of the vapor pressure, if the water content is less than 3%, foaming is insufficient and the desired layer is formed. If the thickness is not obtained and the water content exceeds 10%, the foamed surface may be ruptured, which is not preferable.
[0013]
The thermoplastic resin used for the foamed layer 12 in which the thermoplastic resin (surface) is foamed includes low density polyethylene resin, linear low density polyethylene resin, medium density polyethylene resin, high density polyethylene resin, polypropylene resin, ionomer, ethylene A vinyl acetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / acrylic acid ester copolymer, an ethylene / vinyl alcohol copolymer, a polyester resin, a polyvinyl chloride resin, a polystyrene resin, or the like can be used. The foam layer 12 is laminated on the surface of the paper layer 11 as a base material. As a method of laminating, an extrusion coating method in which a resin is melted and applied, or a laminating method in which a film is bonded is used. The thickness before foaming of the foamed layer 12 in which the thermoplastic resin layer on the surface is foamed is preferably in the range of 10 to 100 μm. When it is less than 10 μm or more than 100 μm, it becomes difficult to foam.
[0014]
In order to provide the convex portion 6 on the foam layer 12, the printing layer 14 is partially provided on the surface of the base material layer 11. The printing layer 14 is applied on the surface of the base material layer 11 and printed at a target position where the convex portion 6 is to be provided. That is, the printed portion promotes foaming of the foamed layer 12 in which the thermoplastic resin layer (surface) provided thereon is foamed, and the convex portion 6 is formed on the paper cup main body 3. As a printing method, gravure printing using a solvent-drying type ink is preferable. The color to be printed is not particularly limited.
[0015]
The thermoplastic resin used for the thermoplastic resin layer (back surface) 13 is a low-density polyethylene resin, a linear low-density polyethylene resin, a medium-density polyethylene resin, a high-density polyethylene resin, a polypropylene resin, an ionomer, as with the foam layer 12. , Ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / vinyl alcohol copolymer, polyester resin, polyvinyl chloride resin, polystyrene resin, etc. can be used. . This thermoplastic resin layer (back surface) 13 is laminated on the back surface of the base material layer 11. As a method of laminating, similarly to the foamed layer 12, an extrusion coating method in which a resin is melted and applied, or a laminating method in which a film is bonded is used. The thickness of the thermoplastic resin layer (back surface) 13 on the back surface is not particularly limited. However, in order to foam only the front surface without foaming the back surface, a layer such as an aluminum foil is provided between the base material layer 11 and the thermoplastic resin layer (back surface) 13 as a method for preventing evaporation of water vapor from the back surface. A thermoplastic resin having a softening point higher than that of the front surface thermoplastic resin is used. For example, in the case of a polyethylene resin, a high-density polyethylene resin having a high softening point is used as the thermoplastic resin on the back surface.
[0016]
Subsequently, the paper winding part 5 is wound around or fitted to the outer periphery of the paper cup body trunk part 3. As shown in FIG. 5, the material configuration of the paper winding portion 5 is based on a base material layer 21 made of paper as a base material, and the back surface side is covered with a foam layer 23 in which a thermoplastic resin layer (back surface) is foamed. ing. A thermoplastic resin layer (surface) 22 is provided on the surface side. An aluminum foil layer or the like may be provided between the base material layer 21 and the thermoplastic resin layer (surface) 22 in order to improve barrier properties. Further, beautiful printing can be performed on the surface of the base material layer 21 or the thermoplastic resin layer (surface) 22.
[0017]
The base material layer 21 is preferably a paper board having printability and suitability for making it into a cylindrical shape, but it is not necessary to dare to use a cup base paper suitable for molding. The basis weight is preferably in the range of 100 to 400 g / m ² . Further, the moisture content of the paper is important, and it is preferably in the range of 3 to 10%, more preferably in the range of 5 to 8%, similarly to the paper layer 11 of the base material of the paper cup body trunk 3. desirable. When the moisture content in the paper is evaporated and the foamed layer 23 is formed by foaming the thermoplastic resin layer on the back surface with the force of the vapor pressure, if the moisture content is less than 3%, the foaming is insufficient and the desired content is obtained. If the thickness is not obtained and the water content exceeds 10%, the foamed surface may be ruptured, which is not preferable.
[0018]
As the thermoplastic resin used for the foamed layer 23 in which the thermoplastic resin layer (back surface) is foamed, the same resin as the foamed layer 12 of the paper cup body trunk 3 can be used. The foam layer 23 is laminated on the back surface of the base material layer 21. As a method of laminating, it can be performed by the same method as the foam layer 12 of the paper cup main body trunk 3. The thickness before foaming of the foamed layer 23 in which the thermoplastic resin layer on the back surface is foamed is preferably in the range of 10 to 100 μm. When it is less than 10 μm or more than 100 μm, it becomes difficult to foam.
[0019]
As the thermoplastic resin used for the thermoplastic resin layer (front surface) 22, the same resin as the foam layer 23 on the back surface can be used. This thermoplastic resin layer (surface) 22 is laminated on the surface of the base material layer 21. As a method of laminating, the same method as that for the foamed layer 23 can be used. The thickness of the surface thermoplastic resin layer (surface) 22 is not particularly limited. However, a layer such as an aluminum foil is provided between the paper layer 21 and the thermoplastic resin layer (front surface) 22 as a method for preventing evaporation of water vapor to the front surface in order to foam only the back surface without foaming the front surface. Alternatively, the thermoplastic resin on the front surface uses a thermoplastic resin having a higher softening point than the thermoplastic resin on the back surface. For example, in the case of a polyethylene resin, a high-density polyethylene resin having a high softening point is used as the thermoplastic resin on the back surface.
[0020]
In the manufacturing method of the heat insulating paper cup of the present invention, first, a laminated body in which a thermoplastic resin layer is laminated on both the front and back surfaces of the base material layer 11 is processed into a fan-shaped blank board of the paper cup main body 3 by punching. Next, the paper cup is formed into a paper cup body together with the bottom by a paper cup molding machine. A laminate having a foamed thermoplastic resin layer can also be used at the bottom. This paper cup body can be manufactured by a general paper cup molding machine. By heating the molded paper cup body, moisture in the paper evaporates and acts by adding its vapor pressure and thermal expansion of air to produce a foam structure in the surface thermoplastic resin layer. Moreover, when providing the convex part 6 on the surface, it prints on the surface of the base material layer 11 beforehand, and the part currently printed by heat processing further promotes foaming, and forms the convex part 6. .
[0021]
As a heating method, hot air, infrared rays, far infrared rays, microwaves, high frequencies, or the like can be used. There are a method of heating by standing or a method of heating while feeding by a conveyor. As heating conditions, the temperature is preferably in the range of 100 to 200 ° C, and the time is preferably in the range of 10 seconds to 5 minutes.
[0022]
After the paper cup main body 2 is heated and foamed, a paper winding part 5 is provided around the outside of the paper cup main body trunk part 3. In one method of winding, as shown in FIG. 6, a tapered tubular paper winding portion 5 is prepared in a separate process in advance, and the paper cup body 2 is inserted into the tubular paper winding portion 5. Mating. Since the front surface of the paper cup main body 3 and the back surface of the paper winding portion 5 are foamed layers, it is difficult to come out after fitting. You may adhere | attach partially with an adhesive agent. As another method, as shown in FIG. 7, there is a method in which the blank of the paper winding part 5 is partially wound around the paper cup body 2 while being bonded with an adhesive, and both ends of the blank are bonded and fixed. In either method, since the foamed surfaces are in contact with each other, the paper cup body 2 and the paper winding portion 5 are integrated in a state in which they are difficult to come off.
[0023]
【Example】
Next, the present invention will be described more specifically with reference to examples.
[Example 1]
First, a cup base paper having a basis weight of 280 g / m ² and a water content of 8.0% is used as a base material layer, and a low-density polyethylene resin layer having a thickness of 40 μm is formed on the back surface as a thermoplastic resin layer (surface). Produced a laminate provided by extrusion coating with a polyethylene resin layer in which 15 μm low density polyethylene and high density polyethylene were mixed as a thermoplastic resin layer (back surface).
Next, this laminated body was punched into a blank for a body portion, and a paper cup body was created by a paper cup molding machine. The paper cup body had an internal capacity of 400 CC (when fully charged), a barrel upper end inner diameter of 88 mm, a bottom inner diameter of 65 mm, and a height of 90 mm.
Further, this paper cup body was heated in a 120 ° C. drier for 3 minutes to prepare a paper cup body having a foam layer on the surface.
On the other hand, for the paper-wrapped portion, first, a base paper having a basis weight of 280 g / m ² and a moisture content of 8.0% is used, and the back surface has a low density of 40 μm as a thermoplastic resin layer (front surface). A laminate was prepared by providing a polyethylene resin layer on the surface with a polyethylene resin layer mixed with 15 μm low density polyethylene and high density polyethylene as a thermoplastic resin layer (back surface) by extrusion coating.
Next, a pattern, a display, or the like was printed on the surface of the laminate, and a fan-shaped blank for a paper winding portion was formed by punching, and both sides were bonded to create a tapered cylindrical paper winding portion. The paper winding portion had an upper end inner diameter of 89 mm, a bottom inner diameter of 66.5 mm, and a height of 88.5 mm.
Furthermore, this paper winding part was heated for 3 minutes in a 120 degreeC dryer, and the paper winding part which has a foaming layer in the back surface was created.
The above-mentioned paper cup body was fitted into the paper winding part and integrated to create a heat insulating paper cup.
[0024]
【The invention's effect】
According to the present invention, the paper cup body also has heat insulation, and since the paper winding portion with heat insulation is provided and the body portion of the paper cup is doubled, the effect of heat insulation is higher and the strength The shape of the paper roll is sufficiently high, the surface of the paper roll has good printability and has an appearance printing effect, and a heat insulating paper cup that can be manufactured at a relatively low cost can be obtained.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view showing an embodiment of a heat insulating paper cup according to the present invention.
FIG. 2 is a partial cross-sectional view showing an embodiment of a heat insulating paper cup according to the present invention.
FIG. 3 is a partial sectional view showing another embodiment of the heat insulating paper cup according to the present invention.
FIG. 4 is a partially enlarged sectional view of a paper cup body of another embodiment of the heat insulating paper cup according to the present invention.
FIG. 5 is a partially enlarged cross-sectional view of a paper winding portion of an embodiment of a heat insulating paper cup according to the present invention.
FIG. 6 is a view showing one method of winding a paper winding portion around a paper cup body in an embodiment of a heat insulating paper cup according to the present invention.
FIG. 7 is a diagram showing another method of winding a paper winding portion around a paper cup body in an embodiment of a heat insulating paper cup according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat insulating paper cup 2 Paper cup main body 3 Paper cup main body trunk | drum 4 Paper cup main body bottom part 5 Paper winding part 6 Protruding part 7 Gap | interval 8 Top curl part 11 Base material layer 12 Foamed layer 13 in which thermoplastic resin layer (surface) foamed 13 Thermoplastic resin layer (Back side)
14 Print layer 21 Base material layer 22 Thermoplastic resin layer (surface)
23 Foam layer with foamed thermoplastic resin layer (back side)

Claims (6)

A paper cup comprising a paper cup body comprising a body part and a bottom part, and a paper winding part fitted to the outer periphery of the body part of the paper cup body, wherein the paper cup body is at least sequentially from the outer surface side, the thermoplastic resin layer (Front surface) comprises a foamed layer obtained by heating and evaporating moisture contained in paper, and foamed by its vapor pressure , a base material layer mainly composed of paper and a thermoplastic resin layer (back surface), Foam obtained by heating and evaporating moisture contained in paper in a thermoplastic resin layer (front surface), a base material layer mainly composed of paper, and a thermoplastic resin layer (back surface) in order from at least the outer surface side. And a heat insulating paper cup.   The foamed layer of the paper cup main body is formed with a part protruding from the other part, and when the paper cup main body and the paper winding part are fitted, the body part of the paper cup main body and the paper winding part. The heat insulating paper cup according to claim 1, wherein a gap is formed between the two.   In the body portion of the paper cup body, a printing layer is partially provided between the foam layer and the base material layer, and the convex portion is formed in a portion of the foam layer that overlaps the print layer. The heat insulating paper cup according to claim 2.   The heat insulating paper cup according to claim 3, wherein the convex portion is continuously formed in an outer peripheral direction of a body portion of the paper cup main body.   The heat insulating paper cup according to claim 3, wherein the convex portion is formed in a vertical direction of a body portion of the paper cup main body.   6. The heat insulating paper cup according to claim 4, wherein the number of the convex portions is plural.

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