JP7464261B2 - Packaging containers - Google Patents

Description

The present invention relates to a packaging container made of a thin resin sheet with legs that have increased rigidity.

Lunch boxes and other foods are often stored in packaging containers made of thin plastic sheets and are displayed and sold on shelves at supermarkets, convenience stores, and other stores. Some of these packaging containers have legs on the bottom to allow them to be placed stably on a shelf or to prevent the bottom from bending when the container is lifted.

An example of a packaging container made of a thin resin sheet with legs is a packaging container having a container body with a mating flange on its outer periphery, and a lid body with mating ridges formed on the inside of the mating flange that will be mated with the mating flange and mated to the container body by the mating ridges, characterized in that a number of legs are formed at the corners of the bottom surface of the container body that bulge downward, and a step is formed between the legs and the mating flange, with the bottom surface of the mating ridges of the lid body facing the container body (see Patent Document 1 below).

JP 2005-8254 A

Packaging containers made of thin resin sheets are often manufactured using methods such as vacuum forming, in which the resin sheet is sucked into a mold shaped like the container, which means that the resin sheet is prone to stretching near the legs, making the wall thickness of that area thinner than other areas and potentially reducing the rigidity of the legs. If the rigidity of the legs is reduced, there is a risk that the legs will be crushed under the load placed on the container body when the lid is placed on it.

One idea to solve this problem is to provide ribs on the side walls of the legs for reinforcement, but the area occupied by the side walls of the legs is small compared to the entire container body, and even if ribs are provided, it is difficult to obtain the necessary rigidity. Furthermore, providing too many ribs could restrict the container design, limiting the design freedom.

Therefore, the object of the present invention is to provide a packaging container that improves the rigidity of the legs with an unprecedented structure while maintaining the freedom of design of the container.

One form of the packaging container of the present invention is a packaging container comprising a container body having a bottom portion and a peripheral wall surface portion provided on its periphery, wherein at least a pair of opposing legs are formed on the bottom portion along the periphery of the bottom portion, the legs have a planar leg bottom surface and at least one crank-shaped bend in the contour of the leg bottom surface, the corners of which are bent alternately left and right, the peripheral wall surface portion has a reinforcing portion continuing from the bend, the reinforcing portion is in a crank shape with corners bent alternately left and right that connects the peripheral wall surface portions which are staggered inward and outward in the main body, and the contours of the leg bottom surfaces of the at least pair of opposing legs are in a point-symmetrical shape.

The packaging container of the above form can increase the rigidity of the legs by providing a bent portion in the legs. In addition, by making the outlines of the bottom surfaces of the opposing legs point-symmetrical, the legs can be made to have the same rigidity, and the rigidity can be made uniform on the left and right.

In the packaging container of the above configuration, in order to further increase the rigidity of the legs, it is preferable that at least one pair of opposing legs have a point-symmetric shape that does not include a plane-symmetric shape at the outer edge of the container at the outline of the bottom surface of the legs, and further, that the bent portion is formed in a crank shape.

In the packaging container of the above-mentioned embodiment, at least one pair of opposing legs can have the inner edge of the container of the contour of the bottom surface of the legs shaped in plane symmetry.
This makes it possible to prevent the bottom portion from bending when the container is lifted.

In the packaging container of the above form, a staggered reinforcing portion can be formed on the peripheral wall surface, continuing from the bent portion and offset inward and outward in the main body. This reinforcing portion is preferably formed over more than half the height of the peripheral wall surface.

In this way, by providing a reinforcing portion on the peripheral wall surface, the rigidity of the peripheral wall surface can be increased without providing a large number of ribs, etc., and the degree of freedom in container design can be maintained.

In the packaging container of the above configuration, the bottom surface can be formed into an elliptical shape in a plan view, and legs can be formed along the opposing curved portions of the periphery.

In this way, the present invention can be suitably used for containers with an elliptical bottom surface in plan view and legs provided along opposing curved portions of the periphery, thereby increasing the rigidity of the legs and peripheral wall surface and maintaining the freedom of design of the container.

1 is a perspective view showing a packaging container according to one embodiment of the present invention, with the lid and the container body separated. FIG. 2 is a plan view showing the container body of FIG. 1 . FIG. 2 is a side view showing the packaging container of FIG. 1 with the lid and the container body separated. 4 is an enlarged end view of the container body of FIG. 1 cut along line AA of FIG. 3. 4 is an enlarged end view of the container body of FIG. 1 cut along line BB of FIG. 3. FIG. 11 is a plan view showing a container body in a packaging container according to another embodiment of the present invention.

Below, one embodiment of the packaging container of the present invention will be described with reference to the drawings.

As shown in Figure 1, a packaging container 1 of one embodiment of the present invention comprises a container body 2 and a lid body 3, and the lid body 3 can be fitted into the container body 2 to cover an opening 2a of the container body 2.
In this embodiment, the container body 2 may be configured to include only the lid 3, but may not include the lid 3. Alternatively, the container body 2 may be configured to include an inner plate that is placed over the opening 2a.

The packaging container 1 has an oval shape in plan view, but is not limited to this, and may have any shape in plan view, such as a square, rectangular, or diamond shape, a circular or elliptical shape in plan view, or a polygonal shape in plan view, such as a hexagon or octagon.

The packaging container 1 can hold, for example, food items, and more specifically, bento lunches, side dishes, sushi, salads, etc.

As shown in Figs. 1 to 4, the container body 2 is formed in a deep bowl shape that is elliptical when viewed from above.
As shown in Figure 1 or Figure 4, the container body 2 comprises a bottom portion 21, a leg portion 22 protruding downward from the bottom portion 21, a peripheral wall portion 23 rising from the periphery of the bottom portion 21, and a fitting portion 24 formed by folding back the upper end portion of the peripheral wall portion 23.

2, the bottom surface 21 is formed as a substantially horizontal surface having an elliptical shape in a plan view. The bottom surface 21 is formed with legs 22 that are C-shaped in a plan view and protrude downward so as to face each other across the center of the bottom surface 22.
The legs 22 are formed along the curved outer edge of the bottom surface 21 and protrude downward by a certain width, with the flat leg bottom surface 22a being adapted to come into contact with a shelf or the like.

As shown in FIG. 2, the leg bottom surface 22a has a bent portion 25a that is bent at a corner around its contour. The bent portion 25a increases the rigidity of the leg 22, making it less likely to be crushed when pressed from above. Each leg 22 needs to have at least one bent portion 25a, but may have two, three or more bent portions. In this embodiment, each leg 22 has two bent portions 25a.

The bent portion 25a is bent at an angle, i.e., at a small radius of curvature, and may be bent at an acute angle, right angle, or obtuse angle, but it is preferable for it to be bent at an angle of about 90° to 120°, and preferably be bent in a crank shape.

The edge portion of the contour around the leg bottom surface 22a that is positioned on the outside of the main body is defined as a main body outer edge portion 22b.
The outer edge 22b of one leg 22 is shaped symmetrically with respect to a point to the outer edge 22b of the opposing other leg 22. By shaping the legs 22 symmetrically, the rigidity of each leg 22 can be made equal, and the rigidity of the container body 2 is equal on the left and right sides.
In particular, it is preferable that the outer edge 22b of one leg 22 has a point-symmetrical shape with respect to the outer edge 22b of the opposing other leg 22, rather than a plane-symmetrical shape.

The edge parallel to the outer body edge 22b of one leg 22, i.e., the edge located on the inside of the body among the contours around the leg bottom surface 22a, is the inner body edge 22c, and the inner body edge 22c is shaped in plane symmetry with the inner body edge 22c of the other opposing leg 22. By making the shape symmetrical, it is possible to make the bottom surface 21 less likely to bend when the container 1 is lifted.

The peripheral wall surface portion 23 rises upward from the periphery of the bottom surface portion 22 (including the outer edge portion 22b of the main body), with approximately the lower half being a flat surface, and approximately the upper half being a multi-step surface portion 23a that extends upward to the outside of the main body. The peripheral wall surface portion 23 and the side walls of the leg portion 22 are connected flush and formed as one unit.

2 and 5, the peripheral wall surface portion 23 is provided with a reinforcing portion 25, which continues upward from the bent portion 25a and is formed in a staggered shape that is offset inward and outward from the main body. By providing the reinforcing portion 25, the rigidity of the side walls of the leg portion 22 and the peripheral wall surface portion 23 can be increased. Furthermore, by connecting the reinforcing portion 25 and the multi-step portion 23a, the rigidity of the peripheral wall surface portion 23 can be further increased.
The reinforcing portion 25 may be bent inward or outward in the clockwise circumferential direction of the container body 2. The reinforcing portion 25 is not particularly limited, but is preferably formed over half or more of the height of the peripheral wall surface portion 23, and is particularly preferably formed over the entire height of the peripheral wall surface portion 23.

The bending angle of the reinforcing portion 25 (including the bent portion 25a) may be any of an obtuse angle, a right angle, and an acute angle, but is preferably about 90° to 120° to match the bent portion 25a.
The offset width of the reinforcing portion 25 is not particularly limited, but is preferably about 1 mm to 5 mm, and more preferably about 2 mm to 4 mm.

As shown in FIG. 4, the upper end of the peripheral wall portion 23 is folded back toward the outside of the main body, and the surface facing the outside of the main body serves as a fitted portion 24 onto which the lid body 3 can be externally fitted.
The fitted portion 24 has an engaging ridge 24a formed around the entire periphery of the body, which protrudes outwardly, and is adapted to engage with a locking portion 34a of the lid 3.
The lower end of the fitted portion 24 projects horizontally to the outside of the container by a certain width, and tongue-like protruding knobs 26 are formed near a pair of opposing corners of the main body 2 .

As shown in FIG. 1 or FIG. 3, the lid 3 has a flat top surface 31, a peripheral wall surface 32 that slopes downward from its periphery, a flange 33 that protrudes horizontally from its lower end to the outside of the lid, and a fitting portion 34 that has a drooping surface and droops from its tip.

The top surface 31 is formed as a horizontal surface that is elliptical in plan view, and along the opposing curved portions of its periphery, there are provided foot rests 31a that are recessed in a C-shape in plan view. The foot rests 31a are used to place the legs 22 of other containers 1, allowing the containers 1 to be stacked one on top of the other.

The peripheral wall surface portion 32 is formed as an inclined plane that widens downward. The flange portion 33 is formed to extend from the lower end of the peripheral wall surface portion 32 to the outside of the lid body at a constant width around the entire periphery of the lid body, and is designed to rest on the upper end of the peripheral wall surface portion 23 of the container body 2.

The fitting portion 34 is formed as a hanging surface that hangs down from the tip of the flange portion 33, and the hanging surface is provided with an engagement portion 34a that protrudes toward the inside of the lid body. The engagement portion 34a is formed at intervals of a predetermined length in the circumferential direction of the lid body 3, and is engaged with the engagement ridge 24a of the container body 2 so that the lid body 3 can be fitted to the outside of the container body 2.

At the lower end of the fitting portion 34, near a pair of opposing corners of the lid body 3, a tongue-shaped knob portion 35 is formed that protrudes horizontally to the outside of the container. The knob portion 35 is arranged to face the knob portion 26 of the container body 2 when the lid body 3 is fitted to the container body 2.

The container body 2 and the lid 3 can be manufactured by thermoforming a synthetic resin sheet, although there is no particular limitation thereto. The synthetic resin sheet may be either a non-foamed resin sheet or a foamed resin sheet, with a non-foamed resin sheet being preferred.
In the case of a non-foamed resin sheet, it is preferable to use a so-called thin resin sheet, specifically, a sheet having a thickness in the range of 0.1 mm to 2.0 mm, particularly 0.2 mm to 1.2 mm.
In the case of a foamed resin sheet, it is preferable to use a sheet having a thickness in the range of 0.5 mm to 4.0 mm, particularly in the range of 0.7 mm to 2.2 mm. In addition, in the case of a foamed resin sheet, it is preferable to set the expansion ratio to 1.05 times to 20.0 times, particularly in the range of 1.5 times to 15.0 times.

As the non-foamed resin sheet, for example, a thermoplastic resin sheet such as a polyolefin resin sheet such as a polyethylene resin sheet or a polypropylene resin sheet, a polyester resin sheet such as a polystyrene resin sheet, a polyethylene terephthalate resin sheet, or a modified polyethylene terephthalate resin sheet with heat resistance can be used. In addition, a sheet that can withstand heating in a microwave oven, for example, a heat-resistant polystyrene resin sheet, a polypropylene resin sheet, or a modified polyethylene terephthalate resin sheet with heat resistance can be used.

As the foamed resin sheet, for example, a foamed polyolefin-based resin sheet, a foamed polystyrene-based resin sheet, a foamed polyester-based resin sheet such as a foamed polyethylene terephthalate resin sheet, etc. can be used.
A laminated sheet obtained by laminating synthetic resin sheets can also be used. Examples of the laminated sheet include a laminated sheet obtained by thermally laminating a resin film onto a non-foamed resin sheet or a foamed resin sheet, a laminated sheet produced by a co-extrusion method, and a laminated sheet produced by an extrusion lamination method.

Examples of thermoforming include vacuum forming, pressure forming, vacuum pressure forming, and hot plate forming.
The container body 2 and the lid 3 may be colored, such as black or white, but are preferably transparent or semi-transparent so that the inside can be seen, and in particular, the lid 3 is preferably transparent or semi-transparent, and the container body 2 is preferably non-transparent, such as black. Furthermore, the surfaces of the container body 2 and the lid 3 may be printed or engraved with letters, patterns, etc., and may be provided with ribs for reinforcement or textured to prevent slipping.

The packaging container 1 can be used, for example, by placing food in the container body 2 and then fitting the lid body 3.

By providing a bent portion 25a at the outer edge portion 22b of the leg 22 of the packaging container 1, the rigidity of the leg 22 can be increased, making the leg 22 less likely to be crushed even when pressed when the lid 3 is put on.
Furthermore, by forming the container outer edge 22b of the leg 22 in a shape that is point symmetrical to the opposing leg 22, the legs 22 can be made to have the same rigidity, and the rigidity can be made uniform on the left and right.
Furthermore, by forming the container inner edge 22c of the leg 22 in a plane symmetrical shape to the opposing leg 22, it is possible to make the bottom portion 21 less likely to bend when the container 1 is lifted.

The packaging container 1 has a reinforcing portion 25 formed on the peripheral wall surface 23 of the container body 2, preferably over half the height of the peripheral wall surface 23 of the container body 2, thereby increasing the rigidity of the side walls of the legs 22 and the peripheral wall surface 23, and furthermore, since it is less noticeable in appearance than concave or convex ribs extending in the vertical direction, the freedom of design of the container can be maintained.

The packaging container 1 has concave or convex ribs extending vertically from the side walls of the legs 22 to the peripheral wall surface 23, but further ribs may be formed in addition to the reinforcing parts 25. Although not shown, the rigidity of the legs 22 can be improved and the legs 22 can be made non-slip by making the bottom surfaces 22a of the legs uneven by knurling or the like.

Figure 6 shows another embodiment of the container body 2A, in which a bent portion 25a is provided near the top of the outer edge 25b of the container, and a reinforcing portion 25 is provided continuous with the bent portion. This also increases the rigidity of the legs 22 and the peripheral wall surface portion 23, and maintains the freedom of design of the container.

The configuration aspects of the above embodiment are not intended to limit the present invention, and modifications are possible as long as the technical objective is the same, and the present invention includes such modifications.

1 Packaging container 2 Container body 21 Bottom surface 22 Leg 22a Leg bottom 22b Container outer edge 22c Container inner edge 23 Peripheral wall 23a Multi-step surface 24 Fitted part 25 Reinforcement 25a Bent part 26 Knob 3 Lid 31 Top 31a Leg rest 32 Peripheral wall 33 Flange 34 Fitting part 24a Locking part 35 Knob

Claims (5)

A packaging container having a container body having a bottom surface portion and a peripheral wall surface portion provided on the periphery of the bottom surface portion,
At least a pair of opposing legs are formed along the periphery of the bottom surface, and the legs have a flat leg bottom surface and at least one crank-shaped bent portion that is bent alternately left and right along the contour of the leg bottom surface . The peripheral wall surface has a reinforcing portion that continues from the bent portion, and the reinforcing portion is formed in a crank shape that is bent alternately left and right and connects the peripheral wall surface portions that are offset in a staggered manner inward and outward in the main body.
The packaging container has at least one pair of opposing legs, the bottom surfaces of which have contours that are point symmetrical. The packaging container according to claim 1, wherein the outer edge of the contour of the bottom surface of at least one pair of opposing legs is point-symmetrical and does not include a plane-symmetrical shape. The packaging container according to claim 1 or 2, wherein at least one pair of opposing legs have a plane-symmetrical shape at the inner edge of the contour of the bottom surface of the legs. 4. The packaging container according to claim 1, wherein the reinforcing portion is formed over at least half the height of the peripheral wall portion. 5. The packaging container according to claim 1 , wherein the bottom portion is formed in an elliptical shape in a plan view , and the legs are formed along opposing curved portions of the periphery thereof.

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