JP7614984B2 - Composite container and method for manufacturing the same - Google Patents

Description

The present invention relates to a composite container and a method for manufacturing a composite container.

In recent years, efforts have been made to reduce the amount of resin used in disposable containers in order to curb the burden on the natural environment caused by plastic waste, including microplastics. Specific efforts include reducing the amount of resin used in plastic containers and replacing plastic products with paper products. In addition, composite containers that combine plastic containers with paper components have also been proposed.

For example, Patent Document 1 proposes a composite container that combines a resin container with a paper sleeve (reinforcing member). In this composite container, the amount of resin is reduced by providing a thin-walled portion with a thickness of 0.01 mm to 0.09 mm in the body of the resin container. However, when such a thin-walled portion is provided in the body, the body is easily deformed and cannot be gripped. Therefore, in this resin container, a flange portion connected to the body, a thick-walled portion connected to the flange portion in the body, and a protrusion that protrudes radially outward from the thick-walled portion are provided, and the thin-walled portion is located on the bottom side of the thick-walled portion. Then, the body of the resin container is inserted into a cylindrical paper sleeve and the sleeve is supported by the protrusion, so that the resin container and the paper sleeve can be easily attached, and the rigidity of the resin container, which is reduced by the thin-walled portion, is reinforced by the sleeve.

JP 2021-116122 A

According to the composite container disclosed in Patent Document 1, the amount of resin in the body is significantly reduced by obtaining rigidity with the paper sleeve. However, a thick section is provided at the top of the body, and the bottom is also made thicker than the thin section to maintain a certain level of strength. As a result, there are relatively many resin parts, and it is necessary to further reduce the amount of resin used. Furthermore, with the composite container, it is necessary to prepare the resin container and the paper sleeve separately, and then attach the paper sleeve to the resin container. This makes the manufacturing process complicated, and there is a need to improve manufacturing efficiency.

The objective of the present invention is to provide a composite container and a manufacturing method thereof that can reduce the amount of resin used and improve manufacturing efficiency.

In order to solve the above problems, the composite container of the present invention has a bottom and sides, and has a storage section constructed using a resin framework and a paper tubular body, the tubular body being one or more paper face pieces shaped into a tube, the framework having a connecting support portion interposed between one end edge and the other end edge of the paper face piece and joining the end edges, the framework having a bottom framework body arranged on the bottom surface and constituting the framework of the bottom surface, and a side framework body arranged on the side surface and constituting the framework of the side surface, the side framework body having a first support portion covered by the paper face piece, the connecting support portion, and a second support portion arranged to be integrated with the connecting support portion, one ends of the first support portion, the connecting support portion and the second support portion are each connected to the bottom framework, and the cross-sectional area of the second support portion is configured to be smaller than the cross-sectional area of the first support portion .

In the composite container of the present invention, it is preferable that the sum of the cross-sectional area of the joint support portion and the cross-sectional area of the second support portion is equal to the cross-sectional area of the first support portion.

In the composite container of the present invention, the bottom framework comprises a bottom frame that forms the outer edge portion of the bottom surface, and a reinforcing portion that is connected from the center position of the bottom surface via the bottom frame to the first support portion, or the second support portion and the connecting support portion, and it is preferable that the bottom framework is covered by a bottom paper panel.

In the composite container according to the present invention, it is preferable that the framework includes a top framework that constitutes the framework of the top surface of the storage section, and the other ends of the first support column, the connecting support column, and the second support column are each connected to the top framework.

It is preferable that the ceiling frame includes a ceiling frame that forms the outer edge of the ceiling surface, and a flange that protrudes outward from the ceiling frame.

In order to solve the above problems, the manufacturing method of the composite container of the present invention is a manufacturing method of a composite container having a bottom surface and side surfaces and a storage section constituted by a resin framework and a paper tubular body, the tubular body being formed into a cylindrical shape by using one or more paper face pieces, the framework body having a joint support part interposed between one end edge and the other end edge of the paper face piece and joining the end edges together, the framework body being comprised of a bottom framework body disposed on the bottom surface and constituting the framework of the bottom surface, and a side framework body disposed on the side surfaces and constituting the framework of the side surfaces. The side framework has a first support portion covered by the paper face piece, the connecting support portion, and a second support portion arranged to be integrated with the connecting support portion, and one end of the first support portion, the connecting support portion and the second support portion are each connected to a bottom framework, and the cross-sectional area of the second support portion is configured to be smaller than the cross-sectional area of the first support portion.The composite container is obtained by placing the paper face piece at a predetermined position as an insert in a mold for molding the framework, and pouring resin into the mold from the bottom side.

According to the composite container of the present invention, the storage section is constructed using a resin framework and a paper tubular body, which allows for a significant reduction in the amount of resin used compared to when the entire storage section is constructed from resin. Furthermore, the framework only needs to be made thick enough to compensate for the strength deficiencies of the paper tubular body alone, so less resin is required for the framework.

The paper tubular body is one or more paper face pieces shaped into a tube. When shaping a paper face piece into a tube, for example, it is necessary to roll one paper face piece and join one end edge to the other end edge. Also, when using multiple paper face pieces, it is necessary to join the end edges of each paper face piece. In the present invention, one end edge of the paper face piece is joined to the other end edge by a joint support part interposed between them. Therefore, for example, by adopting an insert molding method and setting the paper face piece in a predetermined position in a mold for manufacturing a resin framework and filling it with resin, it is possible to eliminate the need to manufacture and assemble the resin part and the paper part separately, thereby improving manufacturing efficiency.

As described above, the composite container and the manufacturing method for the composite container according to the present invention can reduce the amount of resin and improve manufacturing efficiency.

1A is a top view of a composite container according to an embodiment of the present invention, and FIG. 1B is a partial cross-sectional view of the composite container, where the cross-sectional portion represents the A-A cross section of FIG. 2 is a diagram showing a paper side panel and a bottom panel that constitute the cylindrical body of the composite container shown in FIG. 1. FIG. 2 is a cross-sectional view taken along the line CC in FIG. 1. 5A is an enlarged view of an area marked with the symbol D in FIG. 4, and FIG. 5B is an enlarged view of an area marked with the symbol E in FIG. 2A and 2B are side cross-sectional views showing the top surface portion of the composite container shown in FIG. 1, where (a) is a side cross-sectional view at a position corresponding to the A-A section in FIG. 1A, (b) is a side cross-sectional view at a position corresponding to the area surrounded by D in FIG. 1B, and (c) is a side cross-sectional view at a position not corresponding to either the A-A section or the B-B section in FIG. 1A.

The composite container and the manufacturing method of the composite container according to the embodiment of the present invention will be described below with reference to the drawings.

1. Composite Container With reference to Fig. 1, a schematic configuration of a composite container 100 of this embodiment will be described. As shown in Fig. 1(b), the composite container 100 has a bottom surface 11 and a side surface 12, and a storage section 10 with an open top surface 13. The storage section 10 is cup-shaped, and the bottom surface 11 and the top surface 13 are each circular, with the top surface 13 having a larger diameter than the bottom surface 11. The bottom surface 11 and the top surface 13 are coaxial, and a line passing through the center of each surface is defined as a central axis O. However, Fig. 1(a) is a top view showing the composite container 100, and (b) is a partial cross-sectional view of the composite container 100.

The composite container 100 is a hybrid container that integrates resin and paper members. Specifically, the storage section 10 has a framework (hereinafter referred to as framework 20) that is made of resin members, and a paper tubular body 30 is joined to framework 20 to cover it. Hereinafter, with regard to framework 20, the part that constitutes the framework of the side portion of storage section 10 will be referred to as side framework 21, the part that constitutes the framework of the bottom portion will be referred to as bottom framework 22, and the part that constitutes the framework of the top portion will be referred to as top framework 23.

As shown in Figures 1(a) and (b), the side frame 21 has four support pillars (21a, 21b) whose one end is connected to the bottom frame 22 and whose other end is connected to the top frame 23. These four support pillars (21a, 21b) are arranged at equal intervals.

The bottom framework 22 comprises a bottom frame 22a that constitutes the outer edge of the bottom surface 11 of the storage section 10, and a reinforcing section 22b that supplements the strength of the bottom surface 11. The bottom frame 22a is configured as an annular frame with an L-shaped cross section. The reinforcing section 22b is shaped like a cross with the central axis O as its center. The reinforcing section 22b is a plate-like member that extends at 90 degree intervals from the center position of the bottom surface 11, and the ends of the plate-like member are connected to each support section (21a, 21b) and are also connected to the bottom frame 22a.

The top frame 23 comprises a top frame 23a that forms the outer edge of the top surface 13 of the storage unit 10, and a flange 23b that protrudes outward from the top frame 23a. The top frame 23a is configured in the shape of a ring frame with a predetermined length in the height direction. The flange 23b is connected to the top end of the top frame 23a.

In this embodiment, the cylindrical body 30 is formed by rolling up a fan-shaped side paper panel (paper panel) 31 shown in Fig. 2(a) and joining one end edge 31a and the other end edge 31b to form a cylindrical body. As will be described later, the one end edge 31a and the other end edge 31b are joined by a joint support part 21c provided on the side frame body 21.
In this embodiment, the cylindrical body 30 is provided with a circular bottom paper panel 32 for covering the bottom frame 22 shown in Fig. 2(b). As shown in Fig. 1(b), the bottom edge 31c (bottom edge of the cylindrical body 30) of the side paper panel 31 is joined to the bottom frame 22, and its top edge 31d is joined to the top frame 23. The outer peripheral edge of the bottom paper panel 32 is joined to the bottom frame 22a of the bottom frame 22, and its inner surface is joined to the reinforcing part 22b.

Next, the structure of the side frame 21 will be described in more detail with reference to Figures 3 to 5. Figure 3 shows the CC cross section of Figure 1(b). Three of the four support pillars (21a, 21b) 21a are joined to the inner surface of the side paper panel 31 as shown in Figures 3, 4(a) and 5(a). These three support pillars 21a are hereinafter referred to as the first support pillars 21a, and the remaining support pillar 21b is hereinafter referred to as the second support pillar 21b. As shown in Figure 4(a), the width of the joint between the first support pillars 21a and the side paper panel 31 is "w1", the thickness is "w2", and the thickness of the side paper panel 31 is "w3".

4B, the second support portion 21b has the same width "w1" as the first support portion 21a, but its thickness "w4" is thinner than the thickness "w2" of the first support portion 21a. Therefore, the cross-sectional area of the second support portion 21b is smaller than the cross-sectional area of the first support portion 21a.
As shown in Figs. 4(b) and 5(b), the second support portion 21b is provided with a joint support portion 21c so as to protrude radially outward.

As shown in FIG. 4(b), the joint support 21c has the same thickness "w3" as the side paper panel 31, and is interposed between one end edge 31a and the other end edge 31b of the side paper panel 31, joining them. The second support 21b is also joined to the inner surface of the side paper panel 31 near the one end edge 31a and the other end edge 31b.

In the composite container 100 of this embodiment, as an example, "w1" to "w4" have the following values.
w1: 4.0 mm (width of the joint surface between the first support 21a and the side paper panel 31)
w2: 1.0 mm (thickness of the first support portion 21a)
w3: 0.2 mm (thickness of the joint support 21c and the side paper surface 31)
w4: 0.8 mm (thickness of the second support portion 21b)
Height of storage section 10: 90 mm
Diameter of bottom surface 11: 61 mm
Diameter of top surface 13: 85 mm

In this way, in the composite container 100 of this embodiment, w2 = w3 + w4, and the thickness of the first support section 21a (w2) and the sum of the thicknesses of the second support section 21b and the joining support section 21c (w3 + w4) are the same value. However, the values of w1 to w4 can be changed as appropriate depending on the size of the storage section 10 and the strength and thickness of the paper panel 31 on the side.

For example, the width (w1) of the joint surface between the first support portion 21a and the side paper face piece 31 is preferably 5 times or more, more preferably 10 times or more, and even more preferably 15 times or more, the thickness (w3) of the side paper face piece 31. In addition, the width (w1) of the joint surface between the first support portion 21a and the side paper face piece 31 is preferably 35 times or less, more preferably 30 times or less, and even more preferably 25 times or less, the thickness (w3) of the side paper face piece 31.

The thickness (w2) of the first support portion 21a is preferably at least twice the thickness (w3) of the side paper face 31, more preferably at least 2.5 times, and even more preferably at least 3 times. The thickness (w2) of the first support portion 21a is preferably no more than 7 times the thickness (w3) of the side paper face 31, more preferably no more than 6 times, and even more preferably no more than 5.5 times.

Furthermore, the thickness (w4) of the second support portion 21b is preferably 1.5 times or more, more preferably 2 times or more, and even more preferably 2.5 times or more, the thickness (w3) of the side paper face body 31. Furthermore, the thickness (w4) of the second support portion 21b is preferably 6.5 times or less, more preferably 5.5 times or less, and even more preferably 5 times or less, the thickness (w3) of the side paper face body 31. At the same time, the thickness (w4) of the second support portion 21b is preferably less than 1 time the thickness (w2) of the first support portion 21a, preferably 0.95 times or less, more preferably 0.9 times or less, and even more preferably 0.85 times or less.

In this embodiment, the first support portion 21a and the second support portion 21b are each long plates extending from the bottom frame 22 toward the top frame 23, but both corners are rounded on the inside in the radial direction. In this embodiment, the first support portion 21a and the second support portion 21b have different thicknesses (w2, w4) and the R-shapes of both corners are changed to make the cross-sectional shapes of the two different, so that the cross-sectional area of the first support portion 21a is equal to the sum of the cross-sectional areas of the second support portion 21b and the connecting support portion 21c. This provides the effects described below when forming the frame 20.

In addition, in the positions on the side surface 12 of the storage section 10 where the side frame 21 is not present, i.e., where the first support section 21a, the second support section 21b and the connecting support section 21c are not present, as shown in FIG. 5(c), the side surface 12 of the storage section 10 is formed only by the side surface paper panel 31, and the top frame 23 is directly joined to the top edge 31d of the side surface paper panel 31.

In the composite container 100, the type of resin constituting the framework 20 is not particularly limited, but a wide variety of general-purpose resins, such as polypropylene (homopolymer, block copolymer, random copolymer), polyethylene (high density polyethylene, low density polyethylene, etc.), and polyethylene terephthalate resins, which are used as packaging container materials, can be used. In particular, when employing the manufacturing method described below, olefin-based resins such as polypropylene and polyethylene are more preferable.

The paper face pieces (31, 32) that make up the cylindrical body 30 may be formed thin and flat by bonding together vegetable fibers and other fibers, and may be laminated or composite paper made by laminating synthetic paper or various plastics, or functional paper that has been given properties such as water resistance or oil resistance. The basis weight of the paper used can be designed as appropriate. In particular, when adopting the manufacturing method described below, it is more preferable to use laminated paper that has been given properties such as water resistance or oil resistance by laminating an olefin resin layer such as polyethylene resin on the surface.

2. Manufacturing method of the composite container Next, a manufacturing method of the composite container 100 will be described. When manufacturing the composite container 100, so-called insert molding can be adopted. A mold corresponding to the framework 20 and the paper side panel 31 and the paper bottom panel 32 cut to a predetermined shape are prepared. Then, the paper side panel 31 and the paper bottom panel 32 are placed in the mold as inserts at predetermined positions, and resin is poured into the bottom side of the framework 20. The mold is designed to pour the resin into the center position of the reinforcing part 22b of the bottom framework 22.

As described above, the bottom frame 22, the side frame 21, and the top frame 23 are connected to each other. Therefore, the resin poured into the mold from the position corresponding to the center position of the reinforcing part 22b spreads outward in the radial direction and branches into four directions, and flows through the bottom frame 22a to the side frame 21 and the top frame 23 in that order. In this embodiment, the cross-sectional area of the three first support parts 21a that constitute the side frame 21 is equal to the sum of the cross-sectional areas of the second support part 21b and the connecting support part 21c. Therefore, resin is poured into the three first support parts 21a, the second support part 21b, and the connecting support part 21c at the same speed. As a result, the same amount of resin flows into the position corresponding to the top frame 23 of the mold from four places at the same speed, so that the top frame 23a can be evenly filled with resin at the position corresponding to the flange part 23b, and the thickness of the flange part 23b can be made uniform.

At this time, by using a polyolefin resin such as polypropylene as the filling resin material and using laminated paper with a polyolefin resin layer such as a polyethylene layer laminated on at least the surface that is joined to the framework 20 as the side paper face piece 31 and the bottom paper face piece 32, the framework 20 and each paper face piece (31, 32) are thermally fused together during the insert molding, and the framework 20 and each paper face piece (31, 32) can be joined without using adhesives or the like.

According to the composite container 100 described above, the storage section 10 is mainly constituted by the tubular body 30 with the paper side panel 31 in a cylindrical shape, while the strength of the tubular body 30 is supplemented by the resin framework 20. Therefore, compared to when the entire storage section 10 is made of resin, the amount of resin used can be greatly reduced. Furthermore, the framework 20 only needs to be made thick enough to supplement the strength that is lacking with the paper tubular body 30 alone, so the amount of resin required for the framework 20 can be reduced.

Furthermore, the cylindrical body 30 is a single paper side panel 31 formed into a cylindrical shape. In the above embodiment, one end edge 31a and the other end edge 31b of the paper side panel 31 are joined by a joint support 21c interposed therebetween. Therefore, as described above, the composite container 100 can be manufactured by adopting the insert molding method and setting each paper panel (31, 32) as an insert in a predetermined position in a mold for manufacturing the framework 20 and filling it with resin. Therefore, when manufacturing the composite container 100, it is not necessary to separately manufacture and assemble the resin framework 20 and the paper cylindrical body 30, which improves manufacturing efficiency.

Therefore, according to the composite container 100 and the manufacturing method for the composite container 100 of the above embodiment, it is possible to reduce the amount of resin and improve manufacturing efficiency.

The composite container 100 and the manufacturing method of the composite container 100 described above are merely one aspect of the composite container and the manufacturing method of the composite container according to the present invention, and the present invention is not limited to the above embodiment, and can be appropriately modified within the scope of the present invention. For example, in the above embodiment, the framework 20 is joined to the inside of the cylindrical body 30, and the framework 20 is covered by the cylindrical body 30, but the composite container according to the present invention is not limited to this aspect. For example, the framework 20 may be joined to the outside of the cylindrical body 30 so that the framework 20 is not disposed inside the storage section 10, or a part of the framework 20 (for example, a part of the support part 21a or the bottom framework 22, etc.) is joined from the outside of the cylindrical body 30, and the remainder is joined from the inside of the cylindrical body 30. Various aspects can be applied. If the framework 20 is covered with the cylindrical body 30 as in the above embodiment, the framework 20 cannot be seen from the outside, and it is easy to apply various designs to the surface of the cylindrical body 30. Therefore, it is preferable in terms of obtaining a highly designed appearance. On the other hand, if the framework 20 is joined from the outside of the cylindrical body 30, the framework 20 is not present inside the storage section 10, so that, for example, when cosmetics such as yogurt, pudding, or cream are stored in the storage section 10, it is possible to suppress the occurrence of a problem in which the contents adhere to the joint between the framework 20 and the cylindrical body 30 and the contents cannot be removed cleanly. Depending on the contents, it is possible to appropriately select whether the framework 20 is placed inside or outside the cylindrical body 30.

In addition, in the above embodiment, the storage unit 10 is exemplified as a storage unit 10 in which the bottom surface 11 and the top surface 13 are formed in a circular cup shape, but the specific shape of the storage unit 10 is not particularly limited. For example, it may be formed in a deep dish shape or a bottle shape, and the shapes of the bottom surface 11 and the top surface 13 are not limited to circles, but may be square, rectangular, polygonal, etc.

In addition, in the above embodiment, one side paper panel 31 is rolled and one end edge 31a is joined to the other end edge 31b, but the number of side paper panels 31 used to form the side 12 of the storage section 10 is not particularly limited, and two or more sheets may be used and the ends of each side paper panel 31 joined to obtain a tubular body 30. Also, one side paper panel 31 may have a cut portion, and the cut edges may be joined using a part of the side framework 21 as in the above embodiment. In this way, storage sections 10 of various shapes can be formed.

In addition, in the above embodiment, the bottom surface 11 of the storage section 10 is formed using the bottom frame assembly 22 and the bottom paper panel 32, but the shape of the bottom frame assembly 22 is not particularly limited, and as long as the strength of the bottom surface 11 required for the composite container 100 can be maintained, there is no need to provide a reinforcing section 22b. In addition, the entire surface of the bottom surface 11 may be formed from a resin bottom plate material, and the configuration of the bottom surface 11 is not particularly limited.

Similarly, the configuration of the top surface 13 side is not limited to the configuration shown in the above embodiment. In the above embodiment, the entire top surface 13 is open, but it goes without saying that a lid may be provided to cover the top surface 13. Furthermore, a top wall or the like may be provided on the top surface 13, and a discharge port or the like for taking out the contents stored in the storage section 10 may be provided on a part of the top wall.
In addition, while manufacturing the above-mentioned composite container 100 by insert molding results in good manufacturing efficiency, it is also possible to prepare the framework 20 and the paper face pieces 31 and 32 separately and then join the two together by adhering the paper face piece 31 to the framework 20 using an adhesive or by welding them by applying heat locally.

10: Storage section 11: Bottom surface 12: Side surface 13: Top surface 20: Frame body 21: Side frame body 21a: First support section (support section)
21b: Second support section (support section)
21c: Joint support 22: Bottom frame 22a: Bottom frame 22b: Reinforcement 23: Top frame 23a: Top frame 23b: Flange 30: Cylindrical body 31: Side paper panel 31a: Edge 31b: Edge 31c: Bottom edge 31d: Top edge 32: Bottom paper panel 100: Composite container O: Central axis

Claims (6)

The container has a bottom surface and a side surface, and is configured using a resin framework and a paper tubular body.
The cylindrical body is one or more paper face pieces formed into a cylindrical shape,
The framework has a joint support portion interposed between one end side and the other end side of the paper panel and joining the end sides together,
The framework includes a bottom framework disposed on the bottom surface and constituting a framework for the bottom surface, and a side framework disposed on the side surface and constituting a framework for the side surface,
The side frame body has a first support portion covered by the paper face piece, the joint support portion, and a second support portion provided so as to be integrated with the joint support portion,
A composite container, wherein one ends of the first support portion, the joining support portion and the second support portion are each connected to a bottom frame body, and the cross-sectional area of the second support portion is smaller than the cross-sectional area of the first support portion . 2. The composite container according to claim 1 , wherein a sum of a cross-sectional area of the joint strut portion and a cross-sectional area of the second strut portion is equal to a cross-sectional area of the first strut portion. The bottom frame includes a bottom frame that constitutes an outer edge portion of the bottom surface, and a reinforcing portion that is connected from a center position of the bottom surface via the bottom frame to the first support portion or the second support portion and the joint support portion,
3. The composite container according to claim 1 or 2 , wherein the bottom frame is covered with a bottom paper panel. The framework includes a top framework that constitutes a framework of a top surface of the storage unit,
The composite container according to any one of claims 1 to 3 , wherein the other ends of the first support column, the connecting support column and the second support column are each connected to the top frame body. 5. The composite container according to claim 4 , wherein the top frame comprises a top frame that constitutes an outer edge portion of the top surface, and a flange portion that protrudes outward from the top frame. A method for manufacturing a composite container having a bottom surface and a side surface, the container having a storage section formed using a resin framework and a paper tubular body, comprising the steps of:
The cylindrical body is formed into a cylindrical shape using one or more paper faces,
The framework has a joint support portion interposed between one end side and the other end side of the paper panel and joining the end sides together,
The framework includes a bottom framework disposed on the bottom surface and constituting a framework for the bottom surface, and a side framework disposed on the side surface and constituting a framework for the side surface,
The side frame body has a first support portion covered by the paper face piece, the joint support portion, and a second support portion provided so as to be integrated with the joint support portion,
One end of the first support portion, the joint support portion and the second support portion are each connected to a bottom frame body, and a cross-sectional area of the second support portion is configured to be smaller than a cross-sectional area of the first support portion,
A method for manufacturing a composite container, comprising: placing the paper face piece in a predetermined position as an insert in a mold for forming the framework; and pouring resin into the mold from the bottom side to obtain the composite container.

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