JP6867151B2 - How to manufacture paper containers, body blanks, and paper containers - Google Patents

Description

The present invention comprises a paper container, a body material blank , and a paper container, which are made of a laminate obtained by laminating a polyester resin on paper, and in which a body material bonded in a tubular shape and a bottom material molded in a cup shape are bonded to each other. Regarding the manufacturing method.

In recent years, a paper molded body mainly composed of paper as a recyclable resource has been attracting attention from the viewpoint of environmental load. As such a paper molded body, it is made of a laminated body in which synthetic resin is laminated on paper and is attached in a tubular shape. Paper containers made by adhering a combined body material and a cup-shaped bottom material are widely used in applications such as containers for food and drink.

In such a paper container, as shown in FIG. 4, a step portion is formed on the side of the side seal portion 121 in which both end portions 122 and 123 of the body member 120 in the circumferential direction are overlapped and bonded to each other. On the side of the side seal portion 121, a gap region A having a triangular cross section is formed between the bottom member side wall 132 of the bottom member 130 and the body member 120.

Here, when the laminate layers 120b and 130b formed on the surface of the paper are made of a polyethylene resin having a melting point of about 110 ° C. and high fluidity during heating, the laminate layers 120b and 130b are heated by the heat during container molding. Since 130b is melted and the gap region A is closed by the melted polyethylene-based resin, the existence of such a gap region A has not been a problem.

However, in recent years, paper containers have also come to be used as heat-resistant containers for gratin, doria, etc. that are cooked in an oven or the like. In this case, the laminated layers 120b and 130b have a melting point of about 260 ° C. A polyester resin such as PET (polyethylene terephthalate) having a high value may be used.

Although this polyester resin has excellent heat resistance, it has low fluidity when heated. Therefore, when the laminate layers 120b and 130b are formed from the polyester resin, the laminate layers 120b and 130b are melted by the heat during container molding. The function of closing the gap region A cannot be expected.

If the gap region A is not closed, the contents of the paper container may leak through the gap region A, so that it is difficult to develop the application for highly permeable foods and the like.

Japanese Unexamined Patent Publication No. 2015-226863 Japanese Unexamined Patent Publication No. 2014-141282

Therefore, as one idea to solve the above-mentioned problems, by providing a low melting point resin layer having a low melting point between the paper and the laminate layer made of the polyester resin, the low melting point resin is generated by the heat during container molding. It has been proposed to melt the layer and thereby fill the gap region A (see Patent Document 1).

However, in the paper container described in Patent Document 1, since it is necessary to additionally form a low melting point resin layer, not only the manufacturing cost increases but also the low melting point resin layer is formed inside the polyester resin. Therefore, there is a problem that the molten state of the low melting point resin layer tends to vary, and it is difficult to control the flow of the low melting point resin layer satisfactorily.

Further, as another solution, by applying skive hemming processing to one end edge of the body material blank in the circumferential direction, one end edge of the body material blank is formed into a tip shape, and the outer peripheral inclination of one end edge of the body material blank having this tip shape is formed. It has also been proposed to prevent the formation of the gap region A by adhering the side wall of the bottom material along the surface (see Patent Document 2).

However, in the paper container described in Patent Document 2, since one end edge of the body material blank is subjected to skive hemming processing, which is difficult to process, not only the manufacturing cost is increased, but also the shape of one end edge of the body material blank is formed. There is a problem that variation is likely to occur and it is difficult to satisfactorily avoid the formation of the gap region A.

Therefore, the present invention solves these problems, and is a paper container, a body material blank , and a paper container that reliably prevents the contents from leaking through the gap region with a simple structure and low cost. It is an object of the present invention to provide a manufacturing method.

The paper container of the present invention is a paper container made of a laminated body in which a polyester resin is laminated on paper, and a body material bonded in a tubular shape and a bottom material molded in a cup shape are bonded to each other. The material has a first body material end portion arranged on the side close to the bottom material side wall of the bottom material and a second body material end portion arranged on the far side in the side seal portion, and the bottom material side wall. A gap region is formed between the end portion of the first body material and the end portion of the second body material, and when the gap region is viewed in cross section at at least one position in the extending direction of the gap region, the gap region is formed. Solves the above-mentioned problem by being filled with a resin overlay different from the laminated body.
The body material blank of the present invention is a body material blank for a paper container made of a laminate obtained by laminating a polyester resin on paper, and the body material blank is arranged on the side of the side seal portion near the side wall of the bottom material. It has a first body material end portion and a second body material end portion arranged on a distant side, and is arranged so as to face the bottom material side wall side at a position where it is adhered to the bottom material side wall. The resin meat is located on the inner surface of the end portion of the second body material and at a position straddling the boundary portion between the portion overlapped with the end portion of the first body material and the portion not overlapped with the end portion of the first body material. By having a stake, the above-mentioned problem is solved.
In the method for manufacturing a paper container of the present invention, a body material blank and a cup-shaped bottom material provided with the side wall of the bottom material are prepared, and between the end of the first body material and the end of the second body material. The side seal portion is formed by overlapping and crimping a part of the end portion of the first body material and a part of the end portion of the second body material so that a part of the resin overlay is sandwiched between the two parts. The body material blank is formed into a tubular shape , the bottom material is mounted below the tubular body material, the body material and the bottom material are heated, and then the bottom material is pressure-bonded to the body material. As a result, when a cross-sectional view is taken at at least one position in the extending direction of the gap region formed between the bottom material side wall, the first body material end portion, and the second body material end portion, the gap region Is filled with a resin overlay, and a part of the resin overlay is interposed between the opposite surfaces of the first body material end portion and the second body material end portion, and the resin overlay is formed on the bottom material and the bottom material. The problem is solved by forming a paper container that is not interposed between the facing surfaces of the end portions of the first body member.

According to the inventions according to the first and second aspects of the present invention, the body material is arranged on the side of the side seal portion on the side near the side wall of the bottom material and the end portion of the body material on the far side. It has a body material end portion, and a gap region is formed between the bottom material side wall, the first body material end portion, and the second body material end portion, and a cross section is formed at at least one position in the extending direction of the gap region. When viewed, the gap region is filled with the resin overlay, so that the contents of the paper container can be reliably prevented from leaking from the gap region with a simple structure and low cost.
Further, when the resin overlay is a spray forming portion provided on the inner surface of the end portion of the second body material arranged facing the side wall side of the bottom material, the body material before forming the body material into a tubular shape. In the blank state, the resin overlay is sprayed in advance on the inner surface of the end of the second body material, and then the bottom material is attached to the underside of the body material formed into a tubular shape, and the body material and the bottom are mounted. After applying heat to the material, the resin overlay can be melted and the gap region can be closed by the resin overlay by going through a normal molding process of crimping the body material and the bottom material. This eliminates the need for processing such as processing to the edge of the body material blank, which is difficult to process and leads to an increase in manufacturing cost, and the amount of resin overlay provided on the inner surface of the end of the second body material. Since it is possible to freely design the range, material, etc., the gap area can be closed reliably and at low cost.

According to the inventions according to claims 3 and 5, the resin overlay is made of a polyester resin or a resin containing a polyester resin, so that the side seal portion is formed and the bottom material is adhered to the body material. Since it is possible to prevent the resin of the resin overlay from melting down or changing the position of the resin overlay due to the heat applied from time to time, the gap region can be reliably closed at the desired position.
According to the invention of claim 4, the resin overlay is made of a polyester resin having a lower melting point or the same melting point than the polyester resin laminated on paper, so that the resin overlay is applied when the bottom material is adhered to the body material. The resin overlay can be reliably melted by heat, and the gap region can be closed without gaps.
According to the invention of claim 6, a part of the resin overlay is interposed between the facing surfaces of the end of the first body material and the end of the second body material, so that the required manufacturing accuracy can be obtained. It can be kept low. That is, by providing a resin overlay on the inner surface of the end portion of the second body material, the resin overlay is also provided at a position sandwiched between the end portion of the first body material and the end portion of the second body material when the side seal portion is formed. Even if there is a slight deviation in the positional relationship between the end of the first body material and the end of the second body material in the circumferential direction when the end of the first body material and the end of the second body material are overlapped with each other. Since the gap region can be reliably closed by the resin overlay, the required manufacturing accuracy can be suppressed to a low level.
According to the invention of claim 7, since the resin overlay is provided in the gap region on the outer peripheral side of the side wall of the bottom material, the entrance of the gap region facing the accommodating portion side for the contents of the paper container. Since the gap area can be closed in the vicinity, it is possible to reliably prevent the contents from seeping into the gap area.
According to the invention of claim 8, the body material blank is arranged on the side of the side seal portion near the side wall of the bottom material, and the end portion of the second body material arranged on the far side. And, at the position where it is adhered to the side wall of the bottom material, it is formed into a tubular shape by having a resin overlay on the inner surface of the end of the second body material which is arranged facing the side wall of the bottom material. A bottom material is attached to the underside of the body material, heat is applied to the body material and the bottom material, and then the resin overlay is melted and a gap is formed by undergoing a normal molding process of crimping the body material and the bottom material. The area can be closed with a resin overlay. This eliminates the need for processing such as processing to the edge of the body material blank, which is difficult to process and leads to an increase in manufacturing cost, and the amount of resin overlay provided on the inner surface of the end of the second body material. Since it is possible to freely design the range, material, etc., the gap area can be closed reliably and at low cost.

The cross-sectional view which shows the paper container which concerns on one Embodiment of this invention. Explanatory drawing which shows cross-sectional view in the direction of an arrow at the position of line II-II of FIG. Top view showing the body material blank. An explanatory view showing a cross-sectional view of the vicinity of the side seal portion of a conventional paper container.

Hereinafter, the paper container 10 according to the embodiment of the present invention will be described with reference to the drawings.

First, as shown in FIG. 1, the paper container 10 is formed by adhering a cup-shaped bottom member 30 to the lower side of the tubular body member 20.

As shown in FIG. 2, the body material 20 and the bottom material 30 are formed from a laminate in which the laminate layers 20b and 30b made of polyester resin are provided on the surfaces of the base material layers 20a and 30a made of paper, respectively. There is. The laminated layers 20b and 30b are formed on one surface of the base material layers 20a and 30a facing the container 10a side for the contents of the paper container 10.

As shown in FIGS. 1 and 2, the body material 20 has a side seal portion 21 in which both ends in the circumferential direction are bonded to each other, and a first body material 20 arranged on the side seal portion 21 on the side close to the bottom material side wall 32. It has an end portion 22 and a second body material end portion 23 arranged on the side of the side seal portion 21 far from the bottom material side wall 32, and as shown in FIG. 2, a part of the first body material end portion 22. The (tip portion) and a part (tip portion) of the end portion 23 of the second body member are heat-bonded to form a tubular shape.

Further, as shown in FIG. 1, the body material 20 has a bottom-side adhesive portion 24 bonded to the bottom material side wall 32 on the lower side thereof, and the bottom-side adhesive portion 24 is the outer circumference of the bottom material side wall 32. It has an outer peripheral side annular portion 24a arranged on the side and an inner peripheral side annular portion 24b formed continuously at the lower end of the outer peripheral side annular portion 24a and arranged on the inner peripheral side of the bottom member side wall 32. ..

As shown in FIG. 1, the bottom material 30 has a disk-shaped bottom wall 31 and an annular bottom material side wall 32 hanging from the peripheral edge of the bottom wall 31.

Next, the resin overlay 40, which is a feature of the present invention, will be described below.

First, the resin overlay 40 is made of a polyester resin, and as shown in FIG. 2, on the outer peripheral side of the bottom material side wall 32, the bottom material side wall 32, the first body material end portion 22, and the second body material end portion 23 It closes the gap region A having a substantially triangular cross section and is surrounded by.

Specifically, first, the gap region A extends continuously along the vertical direction over the outer peripheral side and the inner peripheral side of the bottom member side wall 32. Then, as shown in FIG. 2, when the gap region A is cross-sectionally viewed at at least one position in the extending direction (vertical direction), the gap region A is filled with the resin overlay 40, and in the present embodiment, the bottom material is filled. At a position on the outer peripheral side of the side wall 32 and near the upper end of the bottom material side wall 32, the resin overlay 40 is filled so as to close the gap region A.

In the explanatory view shown in FIG. 2, the illustration of the inner peripheral side of the bottom material side wall 32 is omitted, that is, the inner peripheral side annular portion 24b of the body material 20 arranged on the inner peripheral side of the bottom material side wall 32. The illustration is omitted.

Further, as shown in FIG. 2, a part of the resin overlay 40 is interposed between the facing surfaces of the first body material end portion 22 and the second body material end portion 23.

Further, as will be described in detail later, the resin overlay 40 is an inner surface (more specifically, more specifically) of the second body material end portion 23 arranged so as to face the bottom material side wall 32 side in the state of the body material blank 25. , It is formed as a thermal spray forming portion provided by spraying a powdery synthetic resin (polyester resin) on the laminated layer 20b) on the inner surface side of the second body member end portion 23.

Next, the manufacturing method of the paper container 10 of the present embodiment will be described below.

First, as shown in FIG. 3, in the state of the body material blank 25, a powdery synthetic resin (polyester-based resin) is formed on the inner surface of the second body material end portion 23 arranged so as to face the bottom material side wall 32 side. The resin overlay 40 is locally formed by spraying.

More specifically, the method for forming the resin overlay 40 will be described in more detail. In the present embodiment, the laminate layer 20b on the inner surface of the end portion 23 of the second body member on which the resin overlay 40 is formed is preheated to near the melting point. Later, the powdered synthetic resin is pressure-fed with a pressurized gas, merged with the heating gas (hot air), and sprayed intermittently or continuously.
Further, to explain the formation position of the resin overlay 40 more specifically, as shown in FIG. 3, the resin overlay 40 is attached to the first body end portion 22 of the inner surface of the second body material end portion 23. It is formed at a position straddling a boundary portion between a portion to be overlapped and a portion not to be overlapped with the end portion 22 of the first body member.

Next, after heating the second body material end portion 23 to melt the laminated layer 20b of the second body material end portion 23, a part (tip portion) of the first body material end portion 22 and the second body material end A side seal portion 21 is formed by overlapping and crimping a part (tip portion) of the portion 23, and the body material blank 25 is formed into a tubular shape.

At this time, as shown in FIG. 2, the first body material end portion 22 and the first body material end portion 22 so as to sandwich a part of the resin overlay 40 between the first body material end portion 22 and the second body material end portion 23. The end portion 23 of the second body member is overlapped.

Next, as shown in FIG. 1, a cup-shaped bottom material 30 is attached below the tubular body material 20, the body material 20 and the bottom material 30 are heated, and then the bottom material 30 is crimped to the body material 20. To do.

At this time, the resin overlay 40 is melted by the heat generated when the bottom material 30 is crimped to the body material 20, and as shown in FIG. 2, when the bottom material side wall 32 is cross-sectionally viewed in the vicinity of the upper end, the gap region is formed. A is filled with the resin overlay 40.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

For example, as the specific type of the polyester-based resin constituting the laminate layers 20b and 30b, any one having easy adhesiveness to paper and heat resistance may be used, and examples thereof include PET (polyethylene terephthalate).

Further, in the above-described embodiment, the resin overlay 40 has been described as being made of a polyester resin such as PET (polyethylene terephthalate), but the specific material of the resin overlay 40 is not limited to this, for example. The resin overlay 40 may be formed from a resin containing a polyester-based resin.
Further, the resin overlay 40 is preferably formed of a polyester resin having a lower melting point or the same melting point as the polyester resin constituting the laminate layers 20b and 30b.

Further, in the above-described embodiment, it has been described that the resin overlay 40 is formed by spraying a powdery synthetic resin on the inner surface of the second body material end portion 23 in the state of the body material blank 25. The method for forming the resin overlay 40 is not limited to the above, and for example, the resin overlay 40 is formed on the inner surface of the second body member end portion 23 by a hot melt gun, a hot runner unit, an injection unit, a 3D printer, or the like. You may. Further, the resin overlay 40 may be formed by thermocompression bonding or insert molding a synthetic resin film or molding member cut out into a predetermined shape.

When the resin overlay 40 is formed by spraying a powdery synthetic resin, the powder of the synthetic resin to be sprayed may be either a synthetic resin before solid-phase polymerization or after solid-phase polymerization, but it is more crystallized. It is preferable to spray a synthetic resin having a low degree of solid-phase polymerization before solid-phase polymerization.

Further, in the above-described embodiment, the resin overlay 40 is on the outer peripheral side and the bottom of the bottom material side wall 32 in the gap region A which is continuous along the vertical direction over the outer peripheral side and the inner peripheral side of the bottom material side wall 32. It has been described as being locally provided near the upper end of the material side wall 32. However, the formation position and range of the resin overlay 40 is not limited to the above, and for example, the resin overlay 40 may be provided in a part of the gap region A on the inner peripheral side of the bottom material side wall 32, and the gap may be provided. The resin overlay 40 may be provided over the entire area A.

Further, in the above-described embodiment, a part of the resin overlay 40 is interposed between the facing surfaces of the first body material end portion 22 and the second body material end portion 23, that is, the side seal portion 21 is formed. At that time, with a part of the resin overlay 40 sandwiched between the first body material end portion 22 and the second body material end portion 23, the first body material end portion 22 and the second body material end portion Although it has been described that the resin overlay 40 is overlapped with the 23 and heat-bonded, it is essential that a part of the resin overlay 40 is interposed between the facing surfaces of the first body member end 22 and the second body member end 23. Absent. That is, in the state of the body material blank 25, only the portion of the inner surface of the second body material end portion 23 that is adjacent to the portion that is overlapped with the first body material end portion 22 and that is not overlapped with the first body material end portion 22. In addition, the resin overlay 40 may be formed.

Further, in the above-described embodiment, the body material 20 and the bottom material 30 have been described as being formed of a laminated body in which the base material layers 20a and 30a are provided with the laminate layers 20b and 30b. The specific embodiment of the laminate constituting the material 30 is not limited to the above, and for example, a printing layer, a similar laminate layer, or the like is formed on one surface of the base materials 20a, 30a opposite to the laminate layers 20b, 30b. It may be formed.

Further, in the above-described embodiment, the bottom adhesive portion 24 of the body member 20 has been described as having the outer peripheral side annular portion 24a and the inner peripheral side annular portion 24b, but the inner peripheral side annular portion 24b is formed. Instead, the bottom side adhesive portion 24 may be composed of only the outer peripheral side annular portion 24a.

10 ・ ・ ・ Paper container 10a ・ ・ ・ Storage part 20 ・ ・ ・ Body material 20a ・ ・ ・ Base material layer (paper)
20b ・ ・ ・ Laminate layer (polyester resin)
21 ・ ・ ・ Side seal part 22 ・ ・ ・ 1st body material end part 23 ・ ・ ・ 2nd body material end part 24 ・ ・ ・ Bottom side adhesive part 24a ・ ・ ・ Outer peripheral side annular part 24b ・ ・ ・ Inner circumference side Ring part 25 ・ ・ ・ Body material blank 30 ・ ・ ・ Bottom material 30a ・ ・ ・ Base material layer (paper)
30b ・ ・ ・ Laminate layer (polyester resin)
31 ・ ・ ・ Bottom wall 32 ・ ・ ・ Bottom material side wall 40 ・ ・ ・ Resin overlay A ・ ・ ・ Gap area

Claims (9)

It is a paper container made of a laminated body made of paper laminated with polyester resin, and made by adhering a body material bonded in a tubular shape and a bottom material molded in a cup shape.
The body material has a first body material end portion arranged on the side close to the bottom material side wall of the bottom material and a second body material end portion arranged on the far side in the side seal portion.
A gap region is formed between the side wall of the bottom material, the end of the first body material, and the end of the second body material.
A paper container characterized in that the gap region is filled with a resin overlay different from the laminated body when cross-sectionally viewed at at least one position in the extending direction of the gap region. The paper container according to claim 1, wherein the resin overlay is a thermal spray forming portion provided on the inner surface of the end portion of the second body member arranged so as to face the side wall side of the bottom material. .. The paper container according to claim 1 or 2, wherein the resin overlay is made of a polyester-based resin. The paper container according to claim 3, wherein the resin overlay is made of a polyester resin having a melting point lower than that of the polyester resin laminated on the paper or having the same melting point. The paper container according to claim 1 or 2, wherein the resin overlay is made of a resin containing a polyester-based resin. A part of the resin overlay is interposed between the end portion of the first body material and the facing surface of the end portion of the second body material.
The paper container according to any one of claims 1 to 5, wherein the resin overlay is not interposed between the bottom material and the facing surface of the end portion of the first body material. The paper container according to any one of claims 1 to 6, wherein the resin overlay is provided in the gap region on the outer peripheral side of the side wall of the bottom material. A body material blank for paper containers made of a laminate of polyester resin laminated on paper.
The body material blank has a first body material end portion arranged on the side closer to the bottom side wall surface and a second body material end portion arranged on the far side in the side seal portion.
A portion of the inner surface of the second body material end portion arranged facing the bottom material side wall side at a position where the bottom material side wall is adhered, and a portion overlapped with the first body material end portion and the said. A body material blank characterized by having a resin overlay at a position straddling a boundary portion between a portion that cannot be overlapped with the end portion of the first body material. It is a manufacturing method of paper containers.
A body material blank according to claim 8 and a cup-shaped bottom material provided with the side wall of the bottom material are prepared.
A part of the first body material end portion and the second body material end part so that a part of the resin overlay is sandwiched between the first body material end part and the second body material end part. The side seal portion is formed by overlapping and crimping a part thereof, and the body material blank is formed into a tubular shape.
By mounting the bottom material below the tubular body material, heating the body material and the bottom material, and then crimping the bottom material to the body material.
When a cross-sectional view is taken at at least one position in the extending direction of the gap region formed between the bottom material side wall, the first body material end portion, and the second body material end portion, the resin meat is formed in the gap region. As the overlay is filled, a part of the resin overlay is interposed between the end portion of the first body material and the facing surfaces of the end portion of the second body material, and the resin overlay is the bottom material and the first body material. A method for manufacturing a paper container, which comprises forming a paper container that does not intervene between the facing surfaces of the end portions of the body material.

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