JP2004018101A - Paper cup and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-resistant paper cup which can be formed by heat-bonding via hot air, has no pin hole occurring, is highly sealable, and is free from phenomena such as foaming and dissolving even if the cup is filled with heated contents or cooked by heat in a microwave oven or the like with contents put in the cup, and a method of manufacturing the cup. <P>SOLUTION: The paper cup has a bent of a bottom member interposed between a barrel and a fold and joined together. A barrel member consists of a base layer of paper, the outermost layer of a polyethylene resin, and the innermost layer of a polypropylene resin or a polyethylene terephthalate resin. A bottom member consists of a base layer of paper and the innermost and outermost layers of a polypropylene resin or a polyethylene terephthalate resin. The method of manufacturing the paper cup includes steps of forming the barrel as a tube by skive-hemming-finishing, interposing the bent part of the bottom member between the barrel and the fold, and heat-bonding by hot air to join with each other. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paper cup, and more particularly, to a paper cup having a heat-resistant polypropylene resin layer or polyethylene terephthalate resin on the inner surface, and a method for producing the same.
[0002]
[Prior art]
Conventionally, a material of a paper cup composed of a body member and a bottom member has a configuration in which a base layer is made of paper and a heat-sealable resin layer is provided as an innermost layer, and for preserving contents. There is also a material configuration in which a barrier layer such as an aluminum foil is provided between the base material layer and the innermost layer. In the paper cup having such a material configuration, a polyethylene resin is mainly used as the resin of the innermost heat-sealable resin layer from the viewpoint of heat-sealability, flexibility, and the like. / Paper layer / polyethylene resin layer, polyethylene resin layer / paper layer / adhesive layer / aluminum foil / polyethylene resin layer.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned material composition, since the innermost layer is made of polyethylene resin, heat resistance is insufficient, for example, frozen foods, especially curry, contents containing a large amount of oil such as stew, or filling in a heated state, When heated in a microwave oven with these contents, foaming or dissolution occurred in the polyethylene resin layer. In particular, when the heating time of the microwave oven is longer than a predetermined time, there is a problem that the above-mentioned phenomenon occurs remarkably.
[0004]
As a substitute for the polyethylene resin, there are various resins having heat resistance, and among them, a polypropylene resin and a polyethylene terephthalate resin are typical. When this polypropylene resin or polyethylene terephthalate resin is used as the innermost layer, in the thermal bonding process, it is possible to thermally bond the polypropylene resins or the polyethylene terephthalate resins, but it is difficult to thermally bond with another different type of resin. When heat bonding with paper, it is necessary to burn with a gas burner. The processing by the gas burner has a problem that a pinhole is easily formed and a special machine is required, which is not preferable in manufacturing.
[0005]
In any case, the use of paper cups has also expanded, and it has been demanded that these paper cups be filled with contents heated to 95 ° C. or higher, or that the contents filled in paper cups be cooked as they are in a microwave oven or the like. In addition, there is a demand for a heat-resistant paper cup that can be used for filling heated contents or heating and cooking in a microwave oven or the like. However, when the innermost layer is made of a heat-resistant polypropylene resin layer or polyethylene terephthalate resin, the thermal adhesiveness to other materials is poor, and it is difficult to form a paper cup with a paper cup molding machine using ordinary hot air thermal bonding. There is a problem.
[0006]
The present invention has been made by paying attention to the above problems, and in order to solve these problems, it is possible to form a paper cup by hot air bonding, without generating pinholes, and having a sealing property. Heat-resistant paper cups that do not generate phenomena such as foaming and dissolution even when the contents are heated and filled in a heated state, or when the contents are placed in a paper cup and cooked in a microwave oven etc. And a method for producing the same.
[0007]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is directed to a body having a body attached in a cylindrical shape, a top curl part obtained by bending an upper end side of the body part, and a folded part obtained by folding the lower end of the body part inward. A member having a bottom portion having a bottom portion and a bent portion obtained by bending an outer peripheral edge of the bottom portion, wherein the bent portion of the bottom member is sandwiched between the trunk portion and the folded portion. A paper cup joined to each other, wherein the body member is a base material layer of paper, the outermost layer is a polyethylene resin, the innermost layer is a laminate of polypropylene resin or polyethylene terephthalate resin as a constituent material, the bottom member is The base material layer is paper, and the innermost layer and the outermost layer are made of a laminate made of polypropylene resin or polyethylene terephthalate resin as a constituent material. A paper cup, characterized in that subjected. The skive hemming process is performed on the inner surface of the bonding portion, or is performed on the inner surface of the bonding portion and the outer surface of the bonding portion. Further, the outermost layer of the body member can be foamed to form a foamed layer.
[0008]
Also, a trunk member having a trunk portion adhered in a cylindrical shape, a top curl portion in which the upper end side of the trunk portion is bent, and a folded portion in which the lower end of the trunk portion is folded inward, a bottom portion and a bottom portion And a bottom member having a bent portion having an outer peripheral edge bent, wherein the body member has a base material layer of paper, an outermost layer of polyethylene resin, and an innermost layer of polypropylene resin or The laminated body made of polyethylene terephthalate resin is a constituent material, the bottom member is a base material layer made of paper, and the innermost layer and the outermost layer are made of a laminated body made of polypropylene resin or polyethylene terephthalate resin as a constituent material. The inner surface of the stuck portion is subjected to skive hemming, and is hot-bonded with hot air to form the body into a tubular shape, and the bottom member is formed between the body and the folded portion. Sandwiches the serial bent portion, a process for manufacturing paper cups, characterized in that joined together by thermal bonding by hot air.
[0009]
According to the present invention, the outermost layer of the body member is made of a polyethylene resin, the innermost layer is made of a polypropylene resin layer or a polyethylene terephthalate resin, and the innermost layer and the outermost layer of the bottom member are made of a polypropylene resin layer or a polyethylene terephthalate resin. This is a manufacturing method in which the body member and the bottom member are joined by heat bonding with air, and the body is sealed with hot air by hot bonding by performing skive hemming processing on the body sealing portion of the body member. This is a manufacturing method of forming the body by heating, and the same kind of resin is thermally bonded to each other.Therefore, there is no pinhole, the sealing property is high, and the contents are filled in a heated state, or the contents are placed in a paper cup. And heat-cook in a microwave oven, etc., do not cause phenomena such as foaming and dissolution, and use a heat-resistant paper cup. Rukoto can.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a partially cutaway plan view showing an example of an embodiment of a paper cup according to the present invention. FIG. 2 is a plan view of a body member according to an example of an embodiment of the paper cup according to the present invention. FIG. 3 is a cross-sectional view showing the joining of the bottom member, and FIG. 3 is a cross-sectional view showing a cross-section of a pasting portion of a trunk portion of a trunk portion of one embodiment of the paper cup according to the present invention; FIG. 5 is a development view showing a blank of an example of the embodiment of the paper cup according to the present invention, and FIG. 5 is a schematic view illustrating a body member / bottom member joining step of the method of manufacturing a paper cup according to the present invention. It is.
[0012]
As shown in FIG. 1, the paper cup A of the present invention has a body 11, which is cylindrically bonded at the bonding portion 1, and a top curl portion 13 in which the upper end side of the body 11 is bent, similarly to a known paper cup. And a bottom member 20 having a bottom portion 21 and a bent portion 22 formed by bending an outer peripheral edge of the bottom portion 21. ing. The bent portion 22 of the bottom member 20 is sandwiched between the body portion 11 and the folded portion 12 of the body member 10 and is joined to each other.
[0013]
The laminate that is the material of the body member 10 has a configuration in which the base layer 10a is a paper layer, the innermost layer 10b is a polypropylene resin layer or a polyethylene terephthalate resin layer, and the outermost layer 10c is a polyethylene resin layer.
[0014]
As the paper layer of the base material layer 10a, it is preferable to use a cup base paper having good suitability for forming a paper cup. The basis weight is not particularly limited, but is preferably in the range of 150 to 300 g / m ² in view of suitability for forming a paper cup.
[0015]
The polypropylene resin used in the polypropylene resin layer of the innermost layer 10b is not particularly limited. For example, a homopolypropylene resin, an ethylene-propylene copolymer, and a polyethylene resin, ethylene-vinyl acetate Resins mixed with a copolymer can be used.
[0016]
The polyethylene terephthalate resin used for the polyethylene terephthalate resin layer of the innermost layer 10b is composed of an ethylene glycol unit and a terephthalic acid unit. Further, if the proportion of a copolymer component such as diethylene glycol is 4 mol% or less, a copolymer with such a copolymer component may be used.
[0017]
Further, a modified polyethylene terephthalate resin comprising a polyethylene terephthalate resin and a copolymer component may be used. In addition to the ethylene glycol unit and the terephthalic acid unit, the modified polyethylene terephthalate resin may have a copolymer component of 5 to 20 mol%, Preferably, they are copolymerized at a ratio of 5 to 15 mol%. Examples of the copolymerization component include aromatic carboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid and p-oxybenzoic acid, and aliphatic or alicyclic compounds such as adipic acid, sebacic acid and cyclohexanedicarboxylic acid. And diols such as aromatic carboxylic acid, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, diethylene glycol, and triethylene glycol. Among these copolymer components, isophthalic acid, 1,4-cyclohexanedimethanol, diethylene glycol and the like are particularly preferred.
[0018]
Although the polyethylene resin used for the polyethylene resin layer of the outermost layer 10c is not particularly limited, for example, a low-density polyethylene resin, a medium-density polyethylene resin, a high-density polyethylene resin, a linear low-density polyethylene resin, or the like is used. can do.
[0019]
Actually, as a method of laminating the innermost layer 10b to the paper layer of the base material layer 10a using a polypropylene resin or a polyethylene terephthalate resin, the polypropylene resin or the polyethylene terephthalate resin is directly coated on the base material layer 10a by an extruder. And a method of sandwich lamination or dry lamination of a polypropylene resin layer or a polyethylene terephthalate resin layer formed by another method with a polyethylene resin.
[0020]
Further, a barrier layer is provided between the paper layer of the base layer 10a and the polypropylene resin layer or the polyethylene terephthalate resin of the innermost layer 10b, or between the paper layer of the base layer 10a and the polyethylene resin layer of the outermost layer 10c. 10d can be provided.
[0021]
As the barrier layer 10d, a material having a property of blocking light such as sunlight or a property of not transmitting water vapor, water, gas, alcohol, or the like can be used, and this may be a single base material. Alternatively, a composite substrate formed by combining two or more types of substrates may be used. Specifically, for example, a film of a resin having an aluminum foil or a deposited film thereof, silicon oxide, a resin film having a deposited film of an inorganic oxide such as aluminum oxide, low-density polyethylene, medium-density polyethylene, high-density polyethylene, For the purpose of any of resin films such as linear low-density polyethylene, polyethylene terephthalate, ethylene-propylene copolymer, and resin films such as polyvinylidene chloride, polyvinyl alcohol, saponified ethylene-vinyl acetate copolymer, etc. Depending on the use, if it is not necessary to heat in a microwave oven, any material may be used for the barrier layer, but if it is necessary to heat in a microwave oven, use of aluminum foil or aluminum evaporated film Is not preferred, an inorganic compound deposited film such as silicon oxide, Styrene - vinyl alcohol copolymer is preferred.
[0022]
On the other hand, the laminate of the bottom member 20 has a configuration in which the base layer 20a is paper and the innermost layer 20b and the outermost layer 20c are both polypropylene resin or polyethylene terephthalate resin. The polypropylene resin or the polyethylene terephthalate resin of the innermost layer 20b and the outermost layer 20c is the same type of resin, and the innermost layer 10b of the body member 10 is the same type of resin.
[0023]
As the paper of the base material layer 20a, it is preferable to use cup base paper having good suitability for forming a paper cup, similarly to the body member 10. The basis weight is not particularly limited, but is preferably in the range of 150 to 300 g / m ² in view of suitability for forming a paper cup.
[0024]
As the polypropylene resin or the polyethylene terephthalate resin of the innermost layer 20b and the outermost layer 20c, the same as the body member 10 can be used.
[0025]
A barrier layer 20d may be provided between the innermost layer 20b and the base material layer 20a or between the outermost layer 20c and the base material layer 20a, as in the case of the body member 10.
[0026]
By using the body member 10 and the bottom member 20 having such a material configuration, the innermost layer 20b and the outermost layer 20c of the bottom member 20 are of the same type of resin in a portion where the body member 10 and the bottom member 20 are joined. Since the innermost layer 10b of the body member 10 is also made of the same type of resin, the bent portion 22 of the bottom member 20 is sandwiched between the body portion 11 and the folded portion 12 of the body member 10 and joined. In this case, as shown in FIG. 2A, the inner surface of the body 11 (that is, the innermost layer 10b of the body member 10) and the inner surface of the bent portion 22 (that is, the innermost layer 20b of the bottom member 20) are formed by hot air bonding. Bonding between the inner surface of the folded portion 12 (that is, the innermost layer 10b of the body member 10) and the outer surface of the bent portion 22 (that is, the outermost layer 20c of the bottom member 20) is the same as the thermal bonding of the same type of resin. Next Since the bonding with the bonding strength is carried out, without the occurrence of pinholes as compared to different paper cup by thermal bonding between the resins as shown in FIG. 2-b, danger of leakage has become extremely small.
[0027]
Further, even if the material forming the body member 10 has a barrier property due to various layer configurations, it is a laminate using paper as the base material layer 10a. There is a possibility that the contents and the like permeate through the paper layer from the cross section of the inner surface portion 2 and leak out. Therefore, as shown in FIG. 3B, the surface of the laminate is removed (skived) at the side of the inner surface 2 of the bonding portion 1 to reduce the thickness of the laminated body, and the thinned portion is folded back. By bonding to the outer surface portion 3 outside the bonding portion 1 after having been in a hemmed state, it is possible to prevent the end face of the paper from being exposed at the inner surface portion 2 of the bonding portion 1. . The end surface treatment of the inner surface part 2 is a known one called skive hemming treatment, and by performing this skive hemming treatment, the innermost layer 10b is heat-bonded to each other in the bonding part 1, and sufficient heat bonding by hot air is sufficient. Adhesive strength can be obtained. As a result, the sealing property of the paper cup A is improved, and the thickness of the bonding portion is prevented from being three times as thick as the packaging material as in the case where the side of the blank 10A is simply folded back. Since the end face of the paper is not exposed, it is possible to use waste paper.
[0028]
In this skive hemming process, if the innermost layer 10b and the outermost layer 10c of the laminate, which is the material used for the body member 10, are the same type of thermoplastic resin, the inner surface 2 and the outer surface 3 of the bonding portion 1 Is a thermal bond between thermoplastic resins of the same type at both the joints 4A and 4B, and there is no problem because sufficient adhesive strength can be obtained. However, when the thermoplastic resin of the innermost layer 10b and the thermoplastic resin of the outermost layer 10c of the laminate are different types, the joint 4A has no problem because the same thermoplastic resin is heat-bonded to each other at the joint 4A. In the portion, different types of thermoplastic resins are thermally bonded to each other, so that a sufficient bonding strength cannot be obtained, and a temporary bonding state occurs, and the portion is easily peeled from the bonding portion 4B. In addition, there is also a danger that moisture and the like permeate through the paper layer from the cross section of the laminate on the outer surface portion 3 of the bonding portion 1 to reduce the strength of the laminate and impair the design of the surface.
[0029]
In order to solve this problem, as shown in FIG. 3C, the bonding portion 1 of the body portion 11 includes the inner surface of the bonding portion 1 in addition to the skive hemming of the inner surface portion 2 of the bonding portion 1. In addition to the portion 2, the outer surface portion 3 can be subjected to skive hemming. At the side edges of the both sides of the blank, which become the inner surface part 2 of the bonding part 1 when bonded, skive hemming is performed from the front side, and at the side edges which become the outer surface part 3 of the other bonding part 1, Skive hemming is applied from the back. When the side edges are overlapped and bonded to form the bonded portion 1, the same type of thermoplastic resin can be thermally bonded. In this way, by using the same type of thermoplastic resin for thermal bonding, the content is protected from being in contact with the cross section of the inner surface portion 2 of the bonding portion 1, and in addition to having sufficient adhesive strength. Also, it is possible to form the bonding portion 1 that prevents moisture and the like from penetrating also from the cross section of the outer surface portion 3.
[0030]
In the body member 10 of the paper cup A of the present invention, the base layer 10a is paper, the outermost layer 10c is a polyethylene resin layer, and the innermost layer 10b is a polypropylene resin or a polyethylene terephthalate resin. The melting point of the polyethylene resin layer is lower than the melting point of the innermost layer 10b of the polypropylene resin or the polyethylene terephthalate resin. Can be foamed. Thus, by forming the polyethylene resin layer of the outermost layer 10c as a foamed layer, a paper cup having heat insulating properties can be obtained.
[0031]
Next, a method for manufacturing the paper cup A of the present invention will be described. In the method of manufacturing the paper cup A, first, a blank 10A of the body member 10 and a blank 20A of the bottom member 20 as illustrated in FIG. Both sides of the blank 10A are attached to the body to form the bonding portion 1, and the side edge portion to be the inner surface portion 2 of the bonding portion 1 has a skive hemming process as shown in FIG. A skive hemming process as shown in FIG. Next, similarly to a general paper cup in which the innermost layer 10b uses a laminate of polyethylene resin, the paper cup A is used in the body member forming step, the bottom member inserting step, the body member / bottom member joining step, and the top curling step. To manufacture.
[0032]
In the body member / bottom member joining step in the paper cup manufacturing method of the present invention, first, bottom hot air processing is performed, and hot air HA is blown out from the tip of the nozzle N to form a cylindrical body as shown in FIG. The portion 11 and the bent portion 22 of the bottom member 20 are heated from the inside.
[0033]
Next, there is bottom curl processing, and as shown in FIG. 5B, the lower end of the body 11 is bent by a bottom curl mold P and joined so as to sandwich the bent portion 22 of the bottom member 20.
[0034]
Subsequently, there is a pressing process. As shown in FIG. 5C, the lower end portion of the body portion 11 is bent by the bottom curl type P by the bottom curling process so as to sandwich the bent portion 22 of the bottom member 20. After joining, the knurled roller R is eccentric from the inside of the joined portion, and is clamped while sandwiching it with the outer mouse Q. Further, there is a top curl step, in which the top curl portion 13 is formed by curling the upper end of the body member 10 outward.
[0035]
As described above, the inner surface is made of polypropylene by the method of manufacturing a paper cup of the present invention in which the body member 11 of the body member 10 and the body member 10 and the bottom member 20 can be bonded by hot air thermal bonding. The paper cup A of the present invention comprising a resin or a polyethylene terephthalate resin can be manufactured.
[0036]
Further, the outermost layer 10c of the body member 10 made of polyethylene resin is foamed by heating and processing using hot air, infrared rays, far infrared rays, microwaves, high frequency waves, etc., thereby producing a foamed paper cup having heat insulating properties. can do. As the heating conditions, the temperature is preferably in the range of 100 to 200 degrees, and the heating time is preferably in the range of 10 seconds to 5 minutes.
[0037]
【Example】
Next, the paper cup of the present invention will be described with reference to examples.
[0038]
<Example 1>
First, as the material of the body member 10, a polyethylene resin (hereinafter may be abbreviated as PE) is coated on the outer surface side of the paper (280 g / m ² ) of the base material layer 10a by an extrusion method, and the outermost layer 10c is formed. The base material layer 10a produced the laminated body of paper by PE. Next, an aluminum foil is laminated on the inner surface side of the paper as a barrier layer 10d by a PE sand method, and finally, a polypropylene resin (hereinafter sometimes abbreviated as PP) as the innermost layer 10b is coated by an extrusion method. Thus, a laminate having the following configuration was produced.
(Outside) PE 20 μm / paper 280 g / m ² / PE 30 μm / Al 9 μm / PP 50 μm (inside)
[0039]
Further, the material of the bottom member 20 was the same as the material of the body member 10 to produce a laminate having the following configuration.
(Outside) PP 50 μm / paper 250 g / m ² / PE 30 μm / Al 9 μm / PP 50 μm (inside)
[0040]
Using the material of the body member 10 and the material of the bottom member 20 produced as described above, a paper cup A was manufactured by the following steps. First, a fan-shaped blank 10A is punched out from the winding of the material of the body member 10 on which printing is performed on the surface, and as shown in FIG. 5, one side edge of the blank 10A is subjected to skive hemming from the surface side, The laminated body was bent so as to prevent the cross section of the laminated body from being exposed, and the side edges were overlapped to form a bonded portion 1 as shown in FIG. Since the bonding portion 1 bonds the PPs of the same material to each other, the bonding was achieved by heat fusion using hot air.
[0041]
On the other hand, the material of the bottom member 20 is supplied to a cup molding machine by winding the material cut into a predetermined size, punched in a circle inline, molded into a bottom portion 12 having a shape as shown in FIG. The bottom portion 12 was formed by supplying the melted portion to the lower portion of the body 11, melting the bonded portion with hot air, and pressing and bonding with a jig. Furthermore, the paper cup A as shown in FIG. 1 was formed by performing top curl.
[0042]
<Example 2>
First, as a material of the body member 10, PE is coated on the outer surface side of the paper (280 g / m ² ) of the base material layer 10a by an extrusion method, and the outermost layer 10c is PE and the base material layer 10a is a paper laminate. The body was made. Next, an aluminum foil is laminated on the inner surface side of the paper as a barrier layer 10d by a PE sand method, and finally, a film of a polyethylene terephthalate resin (hereinafter sometimes abbreviated to PET) as the innermost layer 10b is attached with an adhesive. In addition, a laminate having the following configuration was produced.
(Outside) PE 20 μm / paper 280 g / m ² / PE 30 μm / Al 9 μm / adhesive / PET 50 μm (inside)
[0043]
Further, the material of the bottom member 20 was the same as the material of the body member 10 to produce a laminate having the following configuration.
(Outside) PET 50 μm / adhesive / paper 250 g / m ² / PE 30 μm / Al 9 μm / adhesive / PP 50 μm (inside)
[0044]
Using the material of the body member 10 and the material of the bottom member 20 produced as described above, a paper cup A was manufactured by the following steps. First, a fan-shaped blank 10A is punched out from the winding of the material of the body member 10 on which printing is performed on the surface, and as shown in FIG. 5, one side edge of the blank 10A is subjected to skive hemming from the surface side, The lamination is protected so that the cross section of the laminated body is not exposed, and the other side edge is similarly subjected to skive hemming processing from the back side, and the both side edges are overlapped, and the bonded portion 1 is shown in FIG. And formed into a cylindrical shape. Since the bonding portion 1 bonds PEs and PETs of the same material to each other, bonding having sufficient bonding strength was achieved by heat fusion using hot air.
[0045]
On the other hand, the material of the bottom member 20 is supplied to a cup molding machine by winding the material cut into a predetermined size, punched in a circle inline, molded into a bottom portion 12 having a shape as shown in FIG. The bottom portion 12 was formed by supplying the melted portion to the lower portion of the body 11, melting the bonded portion with hot air, and pressing and bonding with a jig. Furthermore, the paper cup A as shown in FIG. 1 was formed by performing top curl.
[0046]
<Example 3>
The paper cups A and B produced in Example 1 and Example 2 were subjected to heating and foaming treatment through a heating furnace having a heating temperature of 120 ° C. and a heating time of 3 minutes to foam the polyethylene resin of the outermost layer 10 c of the body 11. Thus, a foamed paper cup A 'and a foamed paper cup B' having heat insulating properties were produced.
[0047]
【The invention's effect】
The paper cup of the present invention has a conventional structure in which the outermost layer of the body member is made of polyethylene resin, the innermost layer is made of a polypropylene resin layer or polyethylene terephthalate resin, and the innermost layer and the outermost layer of the bottom member are made of a polypropylene resin layer or polyethylene terephthalate resin. Compared to a paper cup with polyethylene resin as the innermost layer, phenomena such as foaming and dissolution may occur even when filling the contents in a heated state or putting the contents in a paper cup and cooking with a microwave oven. It is characterized by no heat generation and heat resistance.
[0048]
Further, in the method for manufacturing a paper cup of the present invention, the outermost layer of the body member is a polyethylene resin, the innermost layer is a polypropylene resin layer or a polyethylene terephthalate resin, and the innermost layer and the outermost layer of the bottom member are a polypropylene resin layer or a polyethylene terephthalate resin. By doing so, the body member and the bottom member can be joined by thermal bonding using ordinary hot air without using a gas burner or the like, and skive hemming is applied to the body seal portion of the body member. This is a method in which the body can be similarly formed by hot-air bonding using hot air, so that the body can be formed by bonding the same kind of resin to each other. Fill the contents in a heated state without holes, high sealing performance, or put the contents in a paper cup. It is subjected to heat cooking such as microwave ovens, foaming phenomenon does not occur, such as dissolution, in which an effect that it is possible to obtain a paper cup having heat resistance.
[0049]
In addition, by applying skive hemming to the inner surface of the bonding part and also performing skive hemming to the outer surface of the bonding part, the bonding part of the cylindrical body is bonded by hot air. Thereby, it is possible to obtain a paper cup having sufficient adhesion, preventing the contents from penetrating from the cross section of the inner surface, and preventing moisture and the like from penetrating from the outer surface.
[0050]
Further, in the body member of the paper cup of the present invention, since the base material layer is paper, the outermost layer is a polyethylene resin layer, and the innermost layer is a polypropylene resin or a polyethylene terephthalate resin, the melting point of the outermost polyethylene resin layer is reduced. Is lower than the melting point of the innermost layer of the polypropylene resin or polyethylene terephthalate resin, and the heat treatment allows the outermost layer of the polyethylene resin layer to be foamed by utilizing the evaporation of the moisture of the paper of the base layer. As described above, by forming the outermost polyethylene resin layer as a foamed layer, a paper cup having heat insulating properties can be obtained.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view showing an example of a paper cup according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the joining of the body member and the bottom member according to one embodiment of the paper cup of the present invention.
FIG. 3 is a cross-sectional view illustrating a cross-section of a pasting portion of a trunk portion of a body portion according to an embodiment of the paper cup of the present invention.
FIG. 4 is a developed view showing a blank of an example of the embodiment of the paper cup of the present invention.
FIG. 5 is a schematic diagram illustrating a body member / bottom member joining step of the paper cup manufacturing method of the present invention.
[Explanation of symbols]
A paper cup A 'paper cup (foam)
1 bonding part (body)
2 inner surface part (lamination part)
3 outer surface part (lamination part)
4 Joint 4A Joint 4B Joint 10 Body 10A Blank (body)
10a Base layer 10b Innermost layer 10c Outermost layer 10d Barrier layer 11 Body portion 12 Folded portion 13 Top curl portion 20 Bottom member 20A Blank (bottom member)
Reference Signs List 20a Base layer 20b Innermost layer 20c Outermost layer 20d Barrier layer 21 Bottom part 22 Bent part N Nozzle HA Hot air P Bottom curl type Q us

Claims (5)

A trunk member having a cylindrical body, a top curl part bent at the upper end of the trunk part, and a folded part obtained by folding the lower end of the trunk part inward, a bottom part and an outer peripheral edge of the bottom part A paper cup comprising a bottom member having a bent portion having a bent portion, and wherein the bent portion of the bottom member is sandwiched between the body portion and the folded portion and joined to each other,
The body member is a laminate in which the base material layer is paper, the outermost layer is polyethylene resin, the innermost layer is polypropylene resin or polyethylene terephthalate resin, and the bottom member is base material is paper. The inner layer and the outermost layer are made of a laminate made of polypropylene resin or polyethylene terephthalate resin as a constituent material,
A paper cup, wherein the innermost layer of the body member and the innermost layer and the outermost layer of the bottom member are made of the same type of resin, and a skiving hemming process is applied to a bonding portion of the body portion where the body is bonded. 2. The paper cup according to claim 1, wherein the skive hemming process is performed on an inner surface of the bonding unit. 3. The paper cup according to claim 1, wherein the skive hemming process is performed on an inner surface of the bonding portion and an outer surface of the bonding portion. The paper cup according to any one of claims 1 to 3, wherein the outermost layer of the body member is foamed to form a foamed layer. A trunk member having a cylindrical body, a top curl part bent at the upper end of the trunk part, and a folded part obtained by folding the lower end of the trunk part inward, a bottom part and an outer peripheral edge of the bottom part And a bottom member having a bent portion having a bent portion, comprising:
The body member is a laminate in which the base material layer is paper, the outermost layer is polyethylene resin, the innermost layer is polypropylene resin or polyethylene terephthalate resin, and the bottom member is base material is paper. The inner layer and the outermost layer are made of a laminate made of polypropylene resin or polyethylene terephthalate resin as a constituent material,
The innermost layer of the body member and the innermost layer and the outermost layer of the bottom member are made of the same type of resin, and the inner surface portion of the bonded portion of the body, or the inner surface portion and the outer surface portion of the bonded portion. Subjected to a skive hemming process, and thermally bonded by hot air to form the body into a tubular shape, sandwiching the bent portion of the bottom member between the body and the folded portion, using hot air A method for producing a paper cup, wherein the paper cup is joined by heat bonding.

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