JP7733588B2 - Composite containers - Google Patents

Description

The present invention relates to 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.
For example, Patent Document 1 discloses a resin container having a body composed of a thin-walled portion having a thickness of 0.01 mm to 0.09 mm and a thick-walled portion having a protrusion protruding radially outward. However, when the body is composed of such a thin-walled portion, the body is easily deformed and cannot be gripped. Therefore, in this resin container, a flange having a thickness of 0.5 mm to 2.0 mm is provided on the thick-walled portion via a connecting portion, and the body of the resin container is inserted into a cylindrical paper sleeve, and the sleeve is supported by the protrusion, thereby maintaining the strength of the resin container.

Japanese Patent Application Laid-Open No. 2021-116122

The resin container disclosed in Patent Document 1 reduces the amount of resin in the body, but still requires thicker sections and sleeves, requiring a further reduction in the amount of resin. Furthermore, this container requires a paper sleeve to maintain the strength of the body, but the paper sleeve and resin container must be manufactured separately and then combined, making the manufacturing process complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite container that can further reduce the amount of resin used and improve production efficiency, while maintaining the functionality required of the container portion.

In order to solve the above problems, the composite container according to the present invention has a bottom surface and a side surface, and includes a storage section formed using a resin framework and a film body whose edge portions are joined to the framework,
The framework has a joint portion interposed between one end edge portion and the other end edge portion of the film body and covering the entire end surfaces of the one end edge portion and the other end edge portion, and at the joint portion, the end edge portion is folded to protrude from the outer surface of the film body and is embedded in the framework body .

In the above-mentioned composite container, the film body is preferably a single-layer film or a multi-layer film, and includes at least one layer of a polyethylene resin layer, a polypropylene resin layer, a polyethylene terephthalate resin layer, a polyamide resin layer, an ethylene vinyl alcohol resin layer, or an aluminum layer.

In the above composite container, the framework preferably comprises a bottom framework that forms the outer edge of the bottom surface, a top framework that forms the outer edge of the top surface of the storage section, and a side framework that includes the joint and is connected to the bottom framework and the top framework; the side surfaces of the storage section are formed by the side framework and a side film body that forms a cylindrical shape by joining one end edge and the other end edge to the joint; the bottom surface of the storage section is formed by the bottom framework and a bottom film body whose outer edge is joined to the bottom framework; the bottom edge of the cylindrical side film body is joined to the bottom framework and the top edge is joined to the top framework; and the end surfaces of the bottom edge and the top edge are entirely covered by the bottom framework and the top framework, respectively.

This specification discloses the following technique for manufacturing a composite container as an example: This technique is a method for manufacturing the composite container, and is characterized by using a mold having one mold member and another mold member that are separated by a dividing surface, in which the one mold member and the other mold member are combined to form a resin-filled portion having a shape corresponding to the framework, placing the film body between the one mold member and the other mold member so that an edge of the film body is inserted into a joint-forming region in the resin-filled portion having a shape corresponding to the joint, and sandwiching the film body between the one mold member and the other mold member, and filling the resin-filled portion with resin, thereby joining the one edge and the other edge of the film body at the joint, thereby obtaining the composite container in which the framework and the film body are integrated.

In the above-mentioned method for manufacturing a composite container, it is preferable that a convex portion protruding from the dividing surface of one of the mold members toward the other mold member is provided within the joint formation area, and resin is filled into the resin filling portion while the edge portion of the film body is pushed up toward the other mold member by the convex portion.

In the above-mentioned method for manufacturing a composite container, at the position where the edge portion is located within the joint formation area, a recess is provided near the convex portion on the parting surface of one of the mold members, and the convex portion and the recess are arranged in that order from the end face side of the edge portion, and when the resin is filled into the resin filling portion, it is preferable that the edge portion is bent by the resin filling pressure and the recess and the convex portion.

With the composite container of the present invention, the storage section is constructed using a resin framework and a film body, allowing the majority of the storage section to be constructed from the film body, while the framework compensates for the strength that would be lacking if the film body were used alone. Furthermore, because the framework only needs to contain an amount of resin sufficient to compensate for the strength, the amount of resin required to construct the composite container can be reduced.

In addition, in the composite container of the present invention, a joint portion of the framework is interposed between one edge portion and the other edge portion of the film body, and the entire edge surface of each edge portion is covered and joined by the joint portion. For example, if the film body is a multilayer film containing a highly hydrophilic layer, and the edge surface of the film body is a cut surface, this highly hydrophilic layer may be exposed at the edge surface of the film body. In this composite container, the entire edge surface of each edge portion is covered by a resin joint portion while joining the one edge portion to the other edge portion, preventing moisture and other contaminants from entering through the edge surface of the film body at the joint portion and preventing problems such as the film body becoming soft and losing its rigidity, or in the case of a multilayer film, the film peeling from the edge surface, or a decrease in the bonding strength between the edge portions.

Furthermore, the above-described method for manufacturing a composite container can be applied to insert molding. That is, by placing a film body in a predetermined position in a mold and filling the resin filling portion of the mold with resin, the edge of the film body is inserted into the joint formation region, and at the same time as forming the framework, one edge of the film body is joined to the other edge of the film body by the joint to obtain an integrated composite container. This extremely simplifies the manufacturing process and improves manufacturing efficiency.

As described above, according to the composite container of the present invention and the manufacturing method of the composite container disclosed in this specification , by combining a resin framework and a film body, it is possible to reduce the amount of resin and improve manufacturing efficiency, while also maintaining the functionality required of the storage section.

1A and 1B are diagrams for explaining a composite container according to an embodiment of the present invention, in which FIG. 1A is a front view (partial cross-sectional view) of the composite container, and FIG. 1B is a bottom view of the composite container. 2A and 2B are diagrams showing the composite container shown in FIG. 1, in which FIG. 2A is a top view and FIG. 2B is a side view (partial cross-sectional view). 2A and 2B are diagrams showing the film bodies that constitute the film body of the composite container shown in FIG. 1, where (a) shows the side film body that constitutes the side of the storage section, and (b) shows the bottom film body that constitutes the bottom of the storage section. Regarding the composite container shown in Figure 1, (a) is a cross-sectional view taken along the line A-A in Figure 1(a), (b) is a schematic diagram showing the cross-sectional side structure of a mold used to mold the relevant part, and (c) is a schematic diagram for explaining the molding method. Regarding a comparative example for comparison with the composite container shown in FIG. 1, (a) is a view corresponding to FIG. 4(a) in the comparative example, (b) is a schematic diagram showing the side cross-sectional structure of a mold used to mold the relevant part, and (c) is a schematic diagram for explaining the molding method. 4A and 4B are diagrams for explaining a modified example of a composite container according to an embodiment of the present invention, in which (a) is a diagram corresponding to FIG. 4A in the modified example, (b) is a schematic diagram showing the cross-sectional side structure of a mold used to mold the relevant part, and (c) is a schematic diagram for explaining the molding method. 4A and 4B are diagrams for explaining yet another modified example of the composite container according to the embodiment of the present invention, in which (a) is a diagram corresponding to FIG. 4A in the modified example, and (b) is a schematic diagram showing the cross-sectional side structure of a mold used to mold the part.

The following describes a composite container and a method for manufacturing a composite container according to an embodiment of the present invention, with reference to the drawings.

1. Composite Container First, a schematic configuration of a composite container 100 of this embodiment will be described with reference to Figures 1 to 3. Note that Figure 1(a) is a front view (partial cross-sectional view) of the composite container 100, Figure 1(b) is a bottom view, Figure 2(a) is a top view, and Figure 2(b) is a side view (partial cross-sectional view). Note that the hatched portion in Figure 2(a) indicates an annular protruding rib 23f, which will be described later, and does not indicate a cross section.

As shown in Figure 1(a), the composite container 100 has a bottom surface 11 and side surfaces 12, and is equipped with a storage section 10 with an open top surface 13. The composite container 100 has a storage section 10 composed of a resin framework 20 and a film body 30. As shown in Figures 1(b) and 2(a), the storage section 10 is cup-shaped, with the bottom surface 11 and top surface 13 each being coaxially circular, and the top surface 13 having a larger diameter than the bottom surface 11.

As shown in FIG. 3, the film body 30 comprises a side film body 31 and a bottom film body 32, each of which is formed into a predetermined shape. These are joined to the framework 20 to form the bottomed, cylindrical storage section 10. Hereinafter, the line passing through the centers of the bottom surface 11 and top surface 13 will be referred to as the central axis O, the direction along the central axis O will be referred to as the axial direction, the direction perpendicular to the central axis O will be referred to as the radial direction, and the direction circumferential around the central axis O will be referred to as the circumferential direction. When the composite container 100 is placed in the state shown in FIG. 1, the bottom surface 11 side will be referred to as the "lower" side and the top surface 13 side will be referred to as the "upper" side in the axial direction. Note that FIGS. 1(a) and 2(a) each show a cross-sectional view to the right of the central axis O. The configuration of the framework 20 and film body 30 will be described below.

As shown in Figures 1(a) and 1(b) and Figures 2(a) and 2(b), the framework 20 comprises a side framework 21 that forms the framework of the side portions of the storage unit 10, a bottom framework 22 that forms the framework of the bottom portion, and a top framework 23 that forms the framework of the top portion.

As shown in Figures 1(a) and 1(b), the side frame 21 is composed of two support columns 21a and 21b, one end of which is connected to the bottom frame 22 and the other end of which is connected to the top frame 23. The two support columns 21a and 21b are arranged opposite each other across the central axis O. The connecting support column 21a and the reinforcing support column 21b protrude radially outward from the outer surface of the film body 30, i.e., the outer surface of the side film body 31, and are provided as convex ribs that extend axially from the bottom frame 22 to the top frame 23.

Of the two support columns 21a, 21b, the support column 21a corresponds to the joint portion referred to in the present invention. The other support column 21b functions as a reinforcing portion to supplement the strength (rigidity) of the storage section 10. Hereinafter, the support column 21a will be referred to as the joint support column 21a, and the other support column 21b will be referred to as the reinforcing support column 21b. The joint support column 21a joins one end edge 31a and the other end edge 31b of the side film body 31 that constitutes the film body 30. The reinforcing support column 21b is joined (adhered) to the outer surface of the film body 30 (side film body 31). However, in the examples shown in Figures 1(a) and 1(b), the reinforcing support column 21b is an optional configuration, and if the reinforcing support column 21b is not necessary due to the strength required of the storage section 10, the reinforcing support column 21b may be omitted. In this case, the amount of resin can be further reduced. Additionally, the reinforcing support section 21b may be replaced with a joining support section 21a, and the storage section 10 may be constructed by joining two side film bodies 31. These can be changed as desired depending on the size of the storage section 10, and three or more side film bodies 31 may be joined, or the number of reinforcing support sections 21b may be increased.

The bottom frame 22 forms the outer edge of the bottom surface 11 of the storage section 10. As shown in Figures 1(a) and (b), the bottom frame 22 comprises a bottom annular frame 22a arranged on the bottom surface 11 side and a side annular frame 22b arranged on the side surface 12 side. The bottom annular frame 22a is configured as a flat ring with a thin axial thickness. The side annular frame 22b is thin in the radial direction and has a ring-like shape with a predetermined axial length. The bottom frame 22 has a roughly L-shaped cross section, with the outer edge of the bottom annular frame 22a and the lower end of the side annular frame 22b connected by a bottom bone joint 22c (see Figure 1(a)).

The bottom frame 22 is connected to the connecting struts 21a and reinforcing struts 21b of the side frame 21 by connecting portions 22d. As shown in Figures 1(a) and 1(b), the connecting portions 22d are provided from the bottom surface 11 side of the storage section 10 to the side surface 12 side of the bottom bone joint 22c, and are integrated with the connecting struts 21a on the side surface 12 of the storage section 10. Furthermore, as shown in Figures 1 and 2, the outer edge of the bottom film body 32 is joined to the inner edge portion of the bottom annular frame 22a from the inner surface side of the bottom annular frame 22a, and the bottom edge portion 31c of the side film body 31 is joined to the upper end portion of the side annular frame 22b from the outer surface side of the side annular frame 22b.

The top frame 23 forms the outer edge of the top surface 13 of the storage section 10. As shown in Figures 1(a) and 2(b), the top frame 23 comprises an inner frame 23a joined to the top edge 31d of the side film 31, a flange 23b protruding outward from the upper end of the inner frame 23a, and an outer frame 23c suspended from the outer edge of the flange 23b. The inner frame 23a and outer frame 23c each have a predetermined length in the axial direction and are configured as ring frames with a thin radial thickness. In other words, the top frame 23 has a U-shaped cross-section that opens downward, formed by the inner frame 23a, flange 23b, and outer frame 23c. In the composite container 100 of this embodiment, the top frame 23 is configured to have a U-shape in cross section, which allows the thicknesses of the inner frame 23a, flange portion 23b, and outer frame 23c to be thin, making it easier to maintain the required strength even when the amount of resin is reduced.

In addition, in this embodiment, as shown in Figures 1(a) and 1(b), four inner peripheral ribs 23d are provided at equal circumferential intervals along the inner peripheral surface at the lower end of the inner peripheral surface of the outer frame body 23c. The inner peripheral ribs 23d protrude radially inward from the inner peripheral surface of the outer frame body 23c and have a predetermined width in the circumferential direction. By providing the inner peripheral ribs 23d on the inner peripheral surface of the outer frame body 23c, the strength of the top frame body 23 can be increased. Furthermore, when the composite container 100 is used as a refill container, the inner peripheral ribs 23d can be used to fit into an undercut provided at the joint.

A peripheral rib 23e is provided around the entire circumference of the lower end of the outer peripheral surface of the outer frame 23c, protruding radially outward. By providing these inner peripheral ribs 23d and outer peripheral ribs 23e, the strength required for the top surface 13 of the storage unit 10 can be better maintained even when the thicknesses of the inner frame 23a, flange portion 23b, and outer frame 23c are reduced.

Furthermore, in this embodiment, as shown in Figures 1(a), 2(a), and 2(b), an annular convex rib 23f that protrudes axially upward is provided on the top surface 13 of the flange portion 23b. The annular convex rib 23f is used as a contact ring for the packing seal.

Next, the joining state between the framework 20 and the film body 30 (film bodies (31, 32)) will be described. In this embodiment, the film body 30 is formed into a cylindrical shape by rolling up the side film body (film body) 31, which has been cut into a predetermined shape such as a fan shape as shown in Figure 3(a), and joining one end edge 31a to the other end edge 31b with the joining support 21a. The bottom film body 32 has a shape (circular in this embodiment) that corresponds to the shape of the bottom of the storage section 10.

First, we will explain the joining state between the two end edges 31a, 31b of the side surface film body 31 and the joining support 21a. Figure 4(a) is a diagram showing the joining state of this part, and is a cross-sectional view taken along the arrows A-A in Figure 1(a). As shown in Figure 4(a), the joining support 21a is interposed between one end edge 31a and the other end edge 31b of the side surface film body 31, joining them. In this embodiment, the one end edge 31a and the other end edge 31b are embedded within the joining support 21a in a state where they are folded so as to protrude radially outward from the outer surface of the film body 30. By joining the two in this manner, the inner and outer sides of each end edge 31a, 31b of the side surface film body 31 can also be covered with resin, allowing the entire end surface of the side surface film body 31 to be completely coated with resin.

In this embodiment, as shown in FIG. 4(a), one end edge 31a and the other end edge 31b of the side surface film body 31 are each provided with a first fold 31e that forms a mountain fold and a second fold 31f that forms a valley fold when viewed from the outer surface of the composite container 100. In the side surface film body 31, the first fold 31e is positioned more inward than the second fold 31f with respect to the end faces of the end edges 31a and 31b. The first fold 31e and the second fold 31f are also provided substantially parallel to and spaced a predetermined distance from the end faces (edges) of the end edges 31a and 31b, respectively. By providing these first fold 31e and second fold 31f, the end edges 31a and 31b of the side surface film body 31 are folded so as to protrude radially outward from the outer surface of the film body 30, as described above.

In addition, in this embodiment, when the side surface film body 31 is unfolded (see Figure 3(a)), the reinforcing support section 21b is joined to the outer surface of the side surface film body 31 at approximately the midpoint between one end edge section 31a and the other end edge section 31b in the width direction (circumferential direction).

As shown in FIG. 1(b), the bottom edge 31c of the side film body 31 is joined to the upper end of the side annular frame 22b of the bottom frame 22. The top edge 31d of the side film body 31 is joined to the lower end of the inner frame 23a of the top frame 23. In this embodiment, the four corners of the side film body 31 are rounded, resulting in a so-called rounded corner shape. In this embodiment, the bottom edge 31c and top edge 31d of the side film body 31 are joined to the bottom frame 22 and the top frame 23 without being folded, unlike the one edge 31a and the other edge 31b. If the four corners of the side film body 31 are sharp, peeling may occur at the corners when the outer surface of the side film body 31 is joined to the inner surface of the side annular frame 22b of the bottom frame 22 and the inner frame 23a of the top frame 23. In this embodiment, by rounding the four corners, even when the side film body 31 is joined to the frame body 20 on only one side, the bottom edge portion 31c and top edge portion 31d of the side film body 31 are embedded in the bottom frame body 22 and top frame body 23, covering the entire end faces and making the corners less likely to peel off.

The outer edge of the circular bottom film body 32 shown in Figure 3(b) is joined to the inner edge of the bottom annular frame 22a of the bottom frame body 22. The bottom frame body 22 and the top frame body 23 are each joined to the outer surface of the side film body 31. The bottom frame body 22 is also joined to the outer surface of the bottom film body 32.

In the composite container 100, the type of resin constituting the framework 20 is not particularly limited, but a wide range of general-purpose resins can be used, such as polypropylene resin (homopolymer, block copolymer, random copolymer; hereinafter referred to as PP (although oriented polypropylene (OPP) or solid polypropylene (CPP) may also be used) used as packaging container material, polyethylene resin (high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), etc.; hereinafter referred to as PE), and polyethylene terephthalate resin (hereinafter referred to as PET).

The film body 30 (31, 32) refers to a thin surface body. Although it is called the film body 30, any film-like or sheet-like object is generally included in the film body 30. The thickness of the film body 30 is not particularly limited, but can be, for example, approximately 0.01 mm or more and 1 mm or less. The thickness can be appropriately determined depending on the contents to be stored in the storage section 10, their purpose, the size of the storage section 10, etc.

The film body 30 is composed of a single-layer film or a multi-layer film. There are no particular limitations on the layer configuration or layer-constituting materials of the film body 30, but it preferably includes one or more of the following: a PE layer, a PP layer, a PET layer, a PA (polyamide resin/nylon (Ny)) layer, an EVOH (ethylene vinyl alcohol resin) layer, and an aluminum layer (Al layer). When the film body 30 is composed of a single-layer film, it is composed of one of these layers. When the film body 30 is composed of a multi-layer film, it is sufficient that it includes one or more of these layers.

The PA layer and EVOH layer are used as gas barrier layers in food packaging films. The Al layer may also be an aluminum-deposited film layer (PET-deposited layer (VM-PET)) in which aluminum is vapor-deposited on a PET layer or the like. The Al layer is used as a variety of functional layers, such as a gas barrier layer, moisture-proof layer, and light-blocking layer. The film body 30 may also include a polystyrene (PS) layer, a cellophane (PT) layer, etc.

When the film body 30 is a multilayer film, it may contain any one of these layers, or may contain two or more of these layers. In the case of a gas barrier layer, compatibility with polyolefin resins such as polyethylene resin and polypropylene resin may be low, resulting in poor adhesion between the two. Therefore, when creating a multilayer film of a gas barrier layer and the framework body 20, or a gas barrier layer and another polyolefin resin layer, the outermost or inner layer may contain an adhesive layer made of a modified polyethylene resin, modified polyolefin resin, or the like, to which a functional group such as Admer (registered trademark) has been introduced to impart adhesiveness to the polyolefin resin, in order to ensure adhesion (bonding and adhesiveness) between the two as needed.

Examples of layer configurations for multilayer films include PE/EVOH/PE, PE/PA, PE/VM-PET/PE/EVOH/PE, PE/Al/PE, adhesive resin layer/EVOH, etc. Other layer configurations used in various packaging films, such as food packaging films, can also be used as appropriate. Regardless of the layer configuration, when using the manufacturing method described below, it is preferable that the surface that will be joined to the framework 20 be a layer made of a material that is highly compatible (adheres well) with the constituent material of the framework 20.

Furthermore, in the case of a multilayer film, in addition to the above layers, functional layers such as an oxygen absorbing layer containing an oxygen scavenger such as a transition metal or a radical scavenger, or a functional component containing other components other than the resin, may be provided as intermediate layers. In the composite container 100, the entire end surface of each film body 30 is covered by the framework 20. This prevents direct contact between the contents (water, oil, alcohol, etc.) contained in the storage section 10 and these layers. This prevents the components contained in these functional layers from leaching into the storage section 10.
Furthermore, by covering the entire end face of each film body 30 with the framework 20, even when the intermediate layer contains an Al layer or a layer containing a transition metal, it is possible to suppress the discharge phenomenon from the end face when heated in a microwave oven, etc. Therefore, even when the intermediate layer contains a functional layer containing an Al layer or a transition metal, it is possible to make the composite container 100 microwave-safe.

2. Manufacturing Method of Composite Container Next, a manufacturing method of the composite container 100 will be described. When manufacturing the composite container 100, the so-called insert molding method can be applied. A mold 50 (see FIG. 4(b)) corresponding to the framework 20 and side surface film body 31 and bottom surface film body 32 that have been cut into predetermined shapes in advance are prepared. Then, the side surface film body 31 and bottom surface film body 32 are placed in predetermined positions in the mold 50 as inserts, and resin is filled into the mold 50. The composite container 100 can be obtained by this method.

As shown in Figure 4(b), mold 50 comprises one mold member 51 and the other mold member 52 separated by a dividing surface, and by combining one mold member 51 and the other mold member 52, a resin-filled portion corresponding to the shape of frame body 20 is formed. Note that Figure 4(b) shows a side cross-sectional structure of mold 50 near connecting support portion forming region 53, which has a shape corresponding to connecting support portion 21a, as the resin-filled portion. Although not shown, mold 50 also has other resin-filled portions, such as a reinforcing support portion forming region having a shape corresponding to reinforcing support portion 21b, a bottom frame body forming region having a shape corresponding to bottom frame body 22, and a top frame body forming region having a shape corresponding to top frame body 23.

As shown in Figure 4(b), film bodies (31, 32) are placed at predetermined positions on the parting surface between one mold member 51 and the other mold member 52. Note that Figure 4(b) shows the side film body 31 placed at the predetermined position. The film bodies (31, 32) set at the predetermined positions in the mold 50 are sandwiched between both mold members 51, 52.

At this time, as shown in Figure 4(b), one end edge 31a and the other end edge 31b of the side surface film body 31 are inserted into the connecting support portion forming region 53. By filling the mold 50 with resin while the one end edge 31a and the other end edge 31b of the side surface film body 31 are inserted into the connecting support portion forming region 53, the one end edge 31a and the other end edge 31b of the side surface film body 31 are joined by the connecting support portion 21a, and the side surface film body 31 is formed into a cylindrical shape. Similarly, by inserting the bottom end edge 31c, top edge edge 31d, and outer edge of the side surface film body 31 and the bottom film body 32 into the bottom frame forming region and the top frame forming region, respectively, and inserting the side surface film body 31 into the reinforcing support portion forming region, these are joined when the mold 50 is filled with resin, and the composite container 100 described above can be obtained, in which the film body 30 and the frame body 20 are integrated.

As shown in Figure 4(b), in this embodiment, in the joint support portion forming region 53, a convex portion 51a that protrudes toward the other mold member 52 is provided on the parting surface of one mold member 51. Furthermore, a concave portion 51b is provided near this convex portion 51a on the parting surface of one mold member 51. The convex portion 51a and the concave portion 51b are arranged in this order from the end face side of the end edges 31a, 31b on both end edges 31a, 31b of the side film body 31.

Here, the action during resin filling will be explained with reference to Figure 4(c). In Figure 4(c), the part below the dashed dotted line shows the state in which the side film body 31 has been placed on the mold 50, while the part above the dashed dotted line shows the state in which the mold 50 has been filled with resin and the mold 50 has been removed. These parts correspond to Figures 4(b) and (a), respectively.

As shown in Figure 4(c), when the side surface film body 31 is placed in the mold 50, one end edge 31a of the side surface film body 31 is pushed up by the convex portion 51a toward the other mold member 52 (see white arrow A in Figure 4(c)). A space is also created between the one end edge 31a of the side surface film body 31 and the concave portion 51b (see white arrow B in Figure 4(c)). The same is true for the other end edge 31b. When resin is filled into the mold 50 in this state, the one end edge 31a and the other end edge 31b of the side surface film body 31 are pressed toward the parting surface of one mold member 51 at the position indicated by the white arrow B by the resin filling pressure. At this time, because the dividing surface is provided with a convex portion 51a and a concave portion 51b, one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 are folded into the concave portion 51b to form the first fold portion 31e having a mountain fold shape when viewed from the outside. Furthermore, the one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 are folded by the concave portion 51b and the convex portion 51a to form the second fold portion 31f having a valley fold shape when viewed from the outside (see outline arrow C in FIG. 4(c)). By providing such a convex portion 51a and a concave portion 51b on one mold member 51 of the mold 50, the side surface film body 31 cut into a predetermined shape, such as a fan shape, as shown in FIG. 3(a) can be simply placed in the mold 50, and both end edge portions 31a, 31b of the side surface film body 31 joined to the joining support portion 21a in a folded state. In other words, there is no need to fold both edge portions 31a, 31b of the side surface film body 31 into a predetermined shape before placing it in the mold 50.

Here, a polyolefin resin such as polypropylene or polyethylene terephthalate resin is used as the filler resin material filled into the mold 50, and the side film body 31 and the bottom film body 32 are made of a single-layer film such as a polyolefin resin layer such as a polyethylene layer or a polyethylene terephthalate resin layer, or a multilayer film with these layers or an adhesive layer arranged on the outermost surface. This allows the framework 20 and each film body (31, 32) to be thermally fused together during molding, joining the framework 20 and each film body (31, 32) without the need for adhesives or the like.

With the composite container 100 described above, the side film body 31 is cut to a predetermined shape and formed into a cylindrical shape, and the bottom film body 32 is provided, so that the storage section 10 is primarily formed by the film body 30, which forms a cylindrical shape with a bottom, while the resin framework 20 supplements the strength of the film body 30. The thickness of the side film body 31 can be made approximately 1/2 to 1/20 of the thickness of the framework 20, which significantly reduces the amount of resin used compared to when the entire storage section 10 is made of resin. Furthermore, the framework 20 only needs to be thick enough to compensate for the strength shortfalls of the film body 30 alone, so the amount of resin required for the framework 20 can be reduced.

In the above embodiment, one end edge portion 31a and the other end edge portion 31b of the side film body 31 are interposed between them and are joined so that the inner and outer surfaces of the end edges 31a, 31b are covered by the joining support portion 21a. In this way, the entire end surface of each end edge portion 31a, 31b is completely covered. Therefore, even when the composite container 100 is used as a container for holding contents containing moisture, such as food, or liquid, it is possible to prevent the contents from leaking from the joint.

Because the entire end surface of the side surface film body 31 is covered by the connecting support 21a, even if the end surface of the side surface film body 31 is a cut surface, it is possible to prevent moisture and other substances from entering through the cut surface, which would reduce rigidity. Furthermore, even if the side surface film body 31 is made of a multilayer film, the entire end surface is completely covered, which prevents problems such as peeling of the surface layer of the multilayer film or a reduction in the bond strength between the one end edge 31a and the other end edge 31b and the connecting support 21a. Furthermore, if the side surface film body 31 includes a gas barrier layer, the gas barrier layer generally contains hydrophilic groups such as OH groups, making contact with moisture (including water vapor) undesirable. However, in the composite container 100, because the entire end surface of the film body 30 is covered, direct contact between the gas barrier layer and moisture and other substances is prevented. Furthermore, as described above, it is possible to prevent the layer components of the side surface film body 31 from leaking into the storage section 10 through the end edges 31a and 31b. Therefore, by using a film body 30 made of a multilayer film having various functional layers such as a gas barrier layer, an Al layer, and an oxygen absorbing layer, while maintaining the rigidity required of the film body 30 and the good appearance of the composite container 100, it is easy to achieve a layer structure that would be difficult to achieve by blow molding or the like when manufacturing the entire storage section 10.

The composite container 100 can also be manufactured using the insert molding method described above. That is, by placing the side film body 31 and bottom film body 32 of predetermined shapes as inserts in predetermined positions in the mold 50 used to manufacture the framework 20, and then filling the resin filling portion of the mold 50 with resin, the composite container 100 can be manufactured, having an integrated storage section 10 in which the resin framework 20 and film body 30 are joined together.

In this embodiment, as described above, by simply providing a convex portion 51a and a concave portion 51b on the parting surface of one of the mold members 51 that constitutes the mold 50, one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 are placed in predetermined positions on the parting surface of the mold 50 and filled with resin, both end edges 31a, 31b of the side surface film body 31 can be folded, and the inner and outer surfaces of each end edge portion 31a, 31b can be covered from both sides by the joining support portions 21a. Thus, according to this embodiment, even when joining the end edges 31a, 31b with the joining support portions 21a in a folded state, there is no need to previously fold the end edges 31a, 31b, thereby improving manufacturing efficiency. Furthermore, by joining both end edges 31a, 31b of the side surface film body 31 in a folded state, the joint support section 21a can be positioned between both end edges 31a, 31b of the side surface film body 31 and on one side of the side surface film body 31 (the outer surface of the storage section 10 in this embodiment), so that the joint support section 21a does not protrude on the other side (the inner surface in this embodiment) of the side surface film body 31.

Therefore, according to the composite container 100 and the manufacturing method for the composite container 100 of the above embodiment, by combining the resin framework 20 and the film body 30, it is possible to reduce the amount of resin used and improve manufacturing efficiency, while maintaining a good bond between the resin framework 20 and the top edge portion 31d of the film body 30.

On the other hand, for example, the mold 60 shown in Figures 5(b) and (c) has a resin-filled portion corresponding to the shape of the framework 20, such as the joint support portion forming region 63, formed by combining one mold member 61 and the other mold member 62. This mold 60 has a configuration substantially similar to the mold 50 shown in Figures 4(b) and (c) above, except that one mold member 61 does not have the above-mentioned convex portion 51a and concave portion 51b. When using such a mold 60, as in the above embodiment, the side film body 31 and the bottom film body 32 are placed in predetermined positions and resin is filled into the resin-filled portion of the mold 60, thereby producing the composite container 100 having the resin framework 20 and film body 30 joined together to form an integrated storage portion 10.

However, in this case, as shown in Figure 5(b), the entire inner surface of the side surface film body 31 is abutted against the parting surface of one mold member 61, and resin is filled into the joint support portion forming region 63. Therefore, while the outer surfaces of one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 are covered with the resin filler that forms the joint support portion 64, the resin filler does not sufficiently extend to the inner surface, as indicated by the white arrow D in Figure 5(c), making it difficult to cover the entire end surfaces of each end edge portion 31a, 31b with resin filler. As a result, in the resulting composite container 100, the inner surfaces of one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 may be exposed and not covered with resin. If even a portion of the end surface is exposed, moisture may adhere to the end surface and enter the inside of the side surface film body 31 from the end surface, potentially reducing its rigidity. Furthermore, if the side film body 31 is made up of multiple films, problems may occur, such as the surface layer of the multilayer film becoming more susceptible to peeling or the bond strength of the end edge portions 31a, 31b decreasing. In contrast, in the composite container 100 of the above embodiment, the end edge portions 31a, 31b are bonded together while being embedded in the joint support portion 21a, so such problems can be prevented.

The composite container 100 and manufacturing method for the composite container 100 described above are merely one embodiment of the composite container and manufacturing method for the composite container according to the present invention, and the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the framework 20 is primarily joined to the outer surface of the film body 30 (side film body 31, bottom film body 32), but the composite container according to the present invention is not limited to this embodiment. For example, the framework 20 may be primarily joined to the inner surface of the film body 30, and the framework 20 may not be positioned on the outer surface of the storage section 10, or various embodiments may be applied, such as having part of the framework 20 joined from the outer surface of the film body 30 and the remainder joined from the inner surface of the film body 30.

By joining the framework 20 primarily to the outer surface of the film body 30 as in the above embodiment, the framework 20 does not protrude from the inside of the storage section 10. This prevents problems such as the contents adhering to the joint between the framework 20 and the film body 30 when storing cosmetics such as yogurt, pudding, or cream in the storage section 10, making it difficult to remove the contents cleanly.

On the other hand, if the framework 20 is joined mainly from the inner surface side of the film body 30 and is configured so that the framework 20 is covered with the film body 30, the framework 20 can be made invisible from the outside.
In the above embodiment, the side framework 21 is composed of the connecting struts 21a and the reinforcing struts 21b, but if the number of reinforcing struts 21b constituting the side framework 21 is increased in accordance with the strength (rigidity) required of the film body 30, the appearance may be impaired if the number of frameworks 20 on the outer surface of the film body 30 increases. In such a case, it is preferable to join the two so that the frameworks 20 are positioned mainly inside the film body 30.
Furthermore, when the composite container 100 is used as a composite container for use in a bathroom or the like, water droplets may adhere to the outer surface of the composite container 100 due to condensation or the like. If the framework 20 is arranged on the outside of the composite container 100, water droplets that have adhered to the framework 20 may remain attached to the outer surface of the composite container 100, which may make it easier for water to seep in through the edge portions 31a, 31b of the side film body 31, etc. Therefore, for containers that are used in environments where water droplets may adhere, such as a bathroom, or where condensation is likely to occur due to the influence of atmospheric humidity, it is preferable to arrange the framework 20 inside the film body 30.

In this way, it is possible to select whether to place the framework 20 inside or outside the film body 30, depending on the contents and the desired appearance of the composite container 100.

In addition, in the above embodiment, one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 are folded so that they protrude radially outward, and both end edge portions 31a, 31b are joined by the joining struts 21a so as to cover their outer and inner surfaces. However, if, for example, the framework body 20 is joined so that it is positioned primarily inside the film body 30, then the one end edge portion 31a and the other end edge portion 31b of the side surface film body 31 can be folded so that they protrude radially inward, and joined from the inner side of the side surface film body 31 by the joining struts 21a so as to cover their outer and inner surfaces.

Furthermore, when folding one end edge portion 31a and the other end edge portion 31b of the side film body 31, for example, as shown in Figure 6(a), a folding portion 31g may be formed at a position spaced a predetermined distance from each end edge portion 31a, 31b, and folded so as to protrude from the outer surface of the film body 30 approximately parallel to each end edge portion 31a, 31b. In this case, as shown in Figure 6(b), a mold 70 having one mold member 71 and the other mold member 72 is used, and as in the above embodiment, one end edge 31a and the other end edge 31b of the side surface film body 31 are inserted into the joint support portion forming region 73. In the joint support portion forming region 73, the protrusion 71a provided on the dividing surface of one mold member 71 pushes the one end edge 31a and the other end edge 31b toward the other mold member 72, and resin is then filled in. By doing so, both end edges 31a, 31b of the side surface film body 31 are joined to the joint support portion 74 in a folded state.

In addition, in the above embodiment, an example was described in which the side surface film body 31 is joined together with both end edge portions 31a, 31b of the side surface film body 31 folded and both its inner and outer surfaces covered by the joining support portions 21a. However, in the above composite container 100, it is not necessary to fold both end edge portions 31a, 31b of the side surface film body 31.

For example, as shown in Figure 7(a), when the side film body 31 is rolled into a cylindrical shape, one end edge portion 31a and the other end edge portion 31b may be joined by a joint portion (joint support portion 84) that is interposed between them and covers both sides, including the end faces of the side film body 31, at the one end edge portion 31a and the other end edge portion 31b. At this time, as shown in Figure 7(b), a mold 80 is used, which has one mold member 81 and the other mold member 82 and is provided with a joint support portion forming region 83 having recesses on the inner and outer surfaces of the side surface film body 31 into which resin is filled. As in the above embodiment, the side surface film body 31 is inserted into the joint support portion forming region 83 while ensuring that one end edge portion 31a and the other end edge portion 31b are spaced a predetermined distance D1 from each other, and resin is filled into the joint support portion forming region 83, thereby joining both end edges 31a, 31b of the side surface film body 31 to the joint support portions 84.

Unlike the mold 50 used in the above embodiment and the mold 60 shown in the modified example, the mold 80 shown in Figure 7(b) has recesses not only on the outer surface of the one end edge portion 31a and the other end edge portion 31b, but also on the inner surface. Therefore, if the one end edge portion 31a and the other end edge portion 31b are inserted too deeply into the joint support portion forming region 83, the resin filling pressure may cause the one end edge portion 31a and the other end edge portion 31b to bend into an unintended shape. In this way, when the joint support portion 21a is provided so as to protrude on both sides of the one end edge portion 31a and the other end edge portion 31b, and when resin is filled on both sides of the one end edge portion 31a and the other end edge portion 31b, it is preferable to appropriately adjust the insertion depth into the joint support portion forming region 83, the above-mentioned specified distance D1 between the one end edge portion 31a and the other end edge portion 31b, the resin filling pressure, and the distance (specified distance D2) between the gate portion for filling resin into the mold 80 and the one end edge portion 31a and the other end edge portion 31b, depending on the rigidity, etc. of the side surface film body 31.

However, in this case, unlike the above embodiment, the thickness of the joint support portion 84 will be greater. Therefore, from the perspective of reducing the amount of resin, it is preferable to provide the joint support portion 21a on one side of the side surface film body 31, as shown in the above embodiment, and fold one end edge portion 31a and the other end edge portion 31b so that they are embedded in the joint support portion 21a.

Furthermore, in the above embodiment, the side film body 31, which has rounded corners, and the circular bottom film body 32 are joined to the bottom frame body 22 and the top frame body 23, respectively, making the side film body 31 and the bottom film body 32 less likely to peel off from the joints with the bottom frame body 22 and the top frame body 23. However, similar to the one edge portion 31a and the other edge portion 31b, it is also preferable to join these areas so that their inner and outer sides are covered by the respective frame bodies (22, 23). In this case, the joint edge portions may be folded and embedded within the frame body, joining the frame body 20 and the respective film bodies (31, 32) to form a single unit.

In the above embodiment, an example was shown in which the storage section 10 is formed in a cup shape with a circular bottom surface 11 and top surface 13, but the specific shape of the storage section 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 top surface 13 are not limited to circles but may be square, rectangular, polygonal, etc.

In the above embodiment, one side surface film body 31 is rolled up and one end edge 31a is joined to the other end edge 31b. However, the number of side surface film bodies 31 used to form the side surface 12 of the storage section 10 is not particularly limited, and two or more side surface film bodies 31 may be used and the end edges of each side surface film body 31 joined to obtain the film body 30. Furthermore, one side surface film body 31 may have a cut portion, and the cut edges may be joined using a portion of the side frame body 21, as in the above embodiment. In this way, storage sections 10 of a variety of shapes can be formed.

Furthermore, in the above embodiment, the bottom surface 11 of the storage section 10 is formed using the bottom frame assembly 22 and the bottom film body 32, but the shape of the bottom frame assembly 22 is not particularly limited. The bottom frame assembly 22 may be provided with reinforcing ribs, such as crosses, or the entire bottom surface 11 may be formed from a resin bottom surface material; the configuration of the bottom surface 11 is not particularly limited. Note that when the entire bottom surface 11 is formed from a resin bottom surface material, there is no need to use the bottom film body 32, and such an embodiment is also included in the composite container of the present invention.

In addition, in the above embodiment, the side framework 21 was composed of connecting struts 21a and reinforcing struts 21b. However, in the composite container of the present invention, the framework only needs to have a joint between one edge of the film body and the other edge to join them, and other aspects are optional. In other words, if the film body 30 itself meets the required strength, there is no need to provide reinforcing struts 21b, and the side framework 21 may be composed only of connecting struts 21a. Furthermore, the specific configuration of the side framework 21, bottom framework 22, and top framework 23 is optional, as long as any of them has a joint as defined in the present invention.

Furthermore, the outer edge of the bottom film body 32 may be folded in the same manner as one end edge portion 31a and the other end edge portion 31b of the side film body 31, and the two may be joined by being embedded in the bottom annular frame 22a, or the inner surface of the outer edge may not be folded and may be covered by the bottom annular frame 22a. The same applies to the bottom end edge portion 31c and top end edge portion 31d of the side film body 31.

10: Storage section 11: Bottom surface 12: Side surface 13: Top surface 20: Frame body 21: Side frame body 21a: Joint support section (joint section)
21b: Reinforcement support portion 22: Bottom frame body 22a: Bottom annular frame 22b: Side annular frame 22c: Bottom frame joint portion 22d: Connecting portion 23: Top frame body 23a: Inner frame body 23b: Flange portion 23c: Outer frame body 23d: Inner peripheral rib 23e: Outer peripheral rib 23f: Annular convex rib 30: Film body 31: Side film body 31a: Edge 31b: Edge 31c: Bottom edge 31d: Top edge 31e: First folded portion 31f: Second folded portion 31g: Folded portion 32: Bottom film body 50: Mold 51: One mold member 51a: Convex portion 51b: Concave portion 52: Other mold member 53: Joint support portion forming region (joint forming region)
60: Mold 61: Mold member 62: Mold member 63: Joint support portion forming region (joint portion forming region)
64: Joint support portion 70: Mold 71: One mold member 71a: Convex portion 72: Other mold member 73: Joint support portion forming region (joint portion forming region)
74: Joint support portion 80: Mold 81: One mold member 82: Other mold member 83: Joint support portion forming region (joint portion forming region)
84: Joint support portion 100: Composite container

Claims (3)

a storage section having a bottom surface and a side surface, the storage section being configured using a resin framework and a film body whose edge portions are joined to the framework;
the framework has a joint portion interposed between one end edge portion and another end edge portion of the film body and covering the entire end surfaces of the one end edge portion and the other end edge portion,
The end portions at the joints are folded to protrude from the outer surface of the film body and are embedded in the framework body . The composite container according to claim 1, wherein the film body is a single-layer film or a multi-layer film and includes at least one layer of a polyethylene resin layer, a polypropylene resin layer, a polyethylene terephthalate resin layer, a polyamide resin layer, an ethylene vinyl alcohol resin layer, and an aluminum layer. The framework comprises a bottom framework that forms the outer edge of the bottom surface, a top framework that forms the outer edge of the top surface of the storage section, and a side framework that includes the joint and is connected to the bottom framework and the top framework,
the side surface of the storage section is configured by the side framework and a side surface film body that forms a cylindrical shape by joining the one end edge portion and the other end edge portion to the joint portion,
the bottom surface of the storage section is constituted by the bottom frame body and a bottom film body whose outer edge end portion is joined to the bottom frame body,
A composite container as described in claim 1 or 2, wherein the bottom edge portion of the cylindrical side film body is joined to the bottom frame body, and the top edge portion is joined to the top frame body, and the end faces of the bottom edge portion and the top edge portion are entirely covered by the bottom frame body and the top frame body, respectively.