Container for packaging

Abstract

To provide a packaging container that can be easily maintained in a state of being folded in half and reduced in volume.SOLUTION: In a packaging container 100 having a bottom surface 110 and a side wall 120 extending upward from the bottom surface 110, the bottom surface 110 is provided with a folding part 160 configured to allow the bottom surface 110 to be valley-folded, and the bottom surface 110 is provided with jointing parts 152 at line-symmetrical positions about the folding part 160, and the jointing parts 152 are configured to contact each other when the bottom surface 110 is valley-folded.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a packaging container.

Background Art

[0002] Conventionally, packaging containers for storing foods such as meat and fish have been used in supermarkets, convenience stores, etc.

[0003] And when consumers etc. discard the packaging container that had stored the food after purchasing the food, there are known packaging containers such as Patent Document 1 and Patent Document 2, which aim to reduce the volume of this used packaging container. The packaging container of Patent Document 1 is configured such that when the container is folded in half along the fold line, the corners are broken and the respective corners can be engaged with each other, so that the packaging container is folded to reduce the volume. Also, the packaging container of Patent Document 2 is configured such that when two fold lines parallel to the bottom surface are formed and the container is folded in half, the respective corners overlap each other, so that the packaging container is folded to reduce the volume.

[0004] However, in the packaging containers of Patent Document 1 and Patent Document 2, since the container is simply bent at the fold line, the surrounding structure including the fold line tries to return to the original state. Therefore, there is a problem that the packaging container folded in half easily returns to its original shape and it is difficult to maintain the reduced volume state.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, in view of the above problems, the present invention provides a packaging container that is easy to maintain in a state where it is folded in half and reduced in volume.

Means for Solving the Problems

[0007] In order to solve the above problems, the packaging container according to claim 1 of the present invention is a packaging container including a bottom surface and side walls extending upward from the bottom surface, wherein the bottom surface is provided with a folding portion configured to be able to be valley-folded, and the bottom surface is provided with a mating portion at a position symmetric with respect to a line centered on the folding portion. The mating portion is configured to be able to contact each other when the bottom surface is valley-folded. The folding portion is a groove, and the groove is recessed so as to open downward, and the opposite surface of the bottom of the groove protrudes upward.

[0008] According to the above characteristics, when a force is applied in the direction in which the bottom surface becomes valley-folded, the mating portion serves as a fulcrum, and stress is applied so as to tear the folding portion to both sides. Therefore, the folding portion is easily plastically deformed to such an extent that it cannot return to its original shape, or the folding portion is easily torn and cracked. Thus, the packaging container is easily maintained in a state where it is folded in half and reduced in volume.

[0009] Furthermore, the packaging container according to claim 1 of the present invention is characterized in that the mating portion includes an inclined surface inclined along an extension line extending from the center of the folding portion.

[0010] According to the above characteristics, when the bottom surface becomes valley-folded, the inclined surfaces of the mating portion come into surface contact with each other. Therefore, the force from the finger can be firmly received and transmitted, and the mating portion functions as a fulcrum that firmly acts as a fulcrum for applying an external stress in a stable state.

[0011] Furthermore, the packaging container according to claim 2 of the present invention is characterized in that it is made of a foamed synthetic resin.

[0012] According to the above characteristics, by using the foamed synthetic resin, the packaging container has flexibility, making it easier to form valley folds. Furthermore, by using the foamed synthetic resin, when the packaging container is valley-folded and the folded part is bent, it is liable to be plastically deformed to such an extent that the folded part cannot return to its original shape, or to be torn and cracked.

[0013] Furthermore, the packaging container according to the present invention is characterized in that the folded part is a groove or a perforation.

[0014] According to the above characteristics, the folded part can be effectively bent.

[0015] Furthermore, the packaging container according to claim 3 of the present invention is characterized in that the bottom of the groove is thinner than other parts of the groove, and the opposite surface of the bottom of the groove is formed at an acute angle.

[0016] According to the above characteristics, when the packaging container is folded in half, stress is likely to concentrate on the folded part, and the folded part can be effectively deformed.

Effects of the Invention

[0017] The packaging container of the present invention is liable to maintain the state of being folded in half and reduced in volume.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Explanation of Reference Numerals

[0019] 100 Packaging container 110 Bottom surface 120 Side wall 152 Joining part 160 Folding part

Mode for Carrying Out the Invention

[0020] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In this specification, "upward" means the direction upward in the vertical direction when the packaging container is placed on a horizontal plane with the opening of the packaging container facing upward, "downward" means the direction downward in the vertical direction, and "lateral" means the direction in the horizontal direction.

[0021] First, FIGS. 1 and 2 show the packaging container 100 of the present invention. Note that FIG. 1(a) is a plan view of the packaging container 100, FIG. 1(b) is a side view of the packaging container 100, FIG. 2(a) is an end view taken along the line A-A of FIG. 1(a), and FIG. 2(b) is an enlarged end view of the periphery of the folding part of FIG. 2(a).

[0022] As shown in FIGS. 1 and 2, the packaging container 100 has a shallow dish shape that opens upward, and includes a flat bottom surface 110 that is substantially rectangular in plan view, a side wall 120 that extends obliquely upward from the outer periphery 111 of the bottom surface 110, an opening 130 surrounded by the side wall 120 on the upper end side of the side wall 120, and a flange portion 140 that extends laterally from the upper end of the side wall 120.

[0023] Further, at the center of the bottom surface 110, a folded portion 160 extending linearly is provided. As will be described later, this folded portion 160 is the portion that becomes the fold line when the bottom surface 110 is valley-folded. Also, the folded portion 160 extends linearly across the bottom surface 110 and the opposing side wall 120 such that one end 161 of the folded portion 160 is located on one side wall 120 and the other end 162 of the folded portion 160 is located on the other opposing side wall 120. Further, the folded portion 160 is a groove 163 recessed so as to open downward, and the tip 164 of the groove 163 is formed at an acute angle. And the thickness W1 of the tip 164 formed at an acute angle is thinner than the thickness W2 of the other portion of the folded portion 160 (that is, thickness W1 < thickness W2). Therefore, as will be described later, when the packaging container 100 is folded in half, stress is likely to concentrate on the folded portion 160, and the folded portion 160 can be effectively deformed.

[0024] Also, on the bottom surface 110, an upward bulging portion 150 bulging convexly upward is provided, and the back surface side of the upward bulging portion 150 is a recessed portion 151. This upward bulging portion 150 is provided at a line-symmetric position around the folded portion 160 extending linearly. And on the upper end side of the upward bulging portion 150, a mating portion 152 is formed. The mating portion 152 is arranged above the folded portion 160 and is provided at a line-symmetric position with the folded portion 160 extending linearly as the center line P1. As will be described later, this mating portion 152 is configured to be able to contact each other when the bottom surface 110 is valley-folded. Also, when the bottom surface 110 is folded in half, the mating portions 152 will be in pressure contact with each other. By configuring the mating portions 152 to be in surface contact with each other, it is possible to effectively prevent the mating portions 152 from being crushed by the stress during pressure contact.

[0025] Further, as shown in Fig. 1(a), the mating portions 152 on both sides of the folding portion 160 extend linearly along the folding portion 160 in a plan view and are parallel to each other. Further, as shown in Fig. 2(b), in a cross section perpendicular to the extending direction of the folding portion 160, the mating portion 152 is provided with an inclined surface 154 inclined along an extension line P2 extending from the center of the folding portion 160. This inclined surface 154 is configured to be in surface contact with each other when the bottom surface 110 is folded in half. Note that the inclined surface 154 is an inclined surface with a curved surface, but it may be a flat inclined surface without unevenness on the surface. As long as the inclined surfaces 154 can be in surface contact with each other, any shape may be used.

[0026] Also, although one folding portion 160 is provided at the center of the bottom surface 110, it is not limited thereto, and any number of folding portions 160 may be provided at any position on the bottom surface 110, such as two. Also, although the folding portion 160 extends linearly, it is not limited thereto, and it may have any shape, such as a curved shape. Further, although the folding portion 160 extends continuously up to the side wall 120, it is not limited thereto, and as long as it is provided on the bottom surface 110, it does not have to extend up to the side wall 120. Further, the folding portion 160 is in the form of a groove 163 recessed so as to open downward so that stress is likely to concentrate and it is easy to bend, but it is not limited thereto, and it may be in the form of a groove recessed so as to open upward. Also, although the folding portion 160 is in the form of the groove 163, the folding portion 160 may be in the form of a perforation. By providing a perforation on the bottom surface 110, the perforated portion becomes weak against stress and can be effectively bent. Note that the perforation means that portions where the thickness of the bottom surface 110 becomes thin are continuously formed at predetermined intervals. Thus, the folding portion 160 is a portion that becomes a fold line when the bottom surface 110 is valley-folded, and as long as it can be effectively bent, in addition to the form of the groove and the form of the perforation, any form such as locally reducing the thickness may be used.

[0027] Further, the joining part 152 has an inclined surface 154 inclined along an extension line P2 extending from the center of the folding part 160, but is not limited thereto. As long as the bottom surface 110 is valley-folded and they are configured to be able to contact each other, any configuration may be used. For example, the joining part 152 may have a corner part that hangs down from the upper surface of the upwardly bulging part 150 toward the folding part 160, and the corner parts may be configured to be in point contact or line contact with each other when the bottom surface 110 is valley-folded.

[0028] Note that the packaging container 100 is substantially rectangular in plan view, but is not limited thereto. The packaging container 100 can have any shape, such as square in plan view, circular in plan view, polygonal in plan view, etc. Further, the packaging container 100 is formed by sheet molding (for example, vacuum molding, pressure air molding, hot plate pressure air molding, vacuum pressure air molding, double-sided vacuum molding, etc.) using a synthetic resin sheet having a thickness of about 0.1 mm to about 4.0 mm. For example, as the synthetic resin sheet, expanded polystyrene, expanded polypropylene, expanded polyethylene terephthalate, etc. can be used. In this embodiment, the packaging container 100 is made of a foamed synthetic resin. By using the foamed synthetic resin, the packaging container 100 has flexibility and is easily valley-folded. Further, by using the foamed synthetic resin, when the packaging container 100 is valley-folded and the folding part 160 is bent, the folding part 160 is plastically deformed to such an extent that it cannot return to its original shape, or is easily torn and cracked.

[0029] Next, an embodiment of folding the packaging container 100 in half is shown in FIG. 3. FIG. 3(a) is an end view taken along the line A-A of FIG. 1(a), showing a state where a finger is placed on the recessed part 151, and FIG. 3(b) is an end view showing a state where the packaging container 100 is folded in half from the state of FIG. 3(a).

[0030] As shown in Fig. 3(a), when a consumer or the like discards the packaging container 100 that had contained food after purchasing the food, in order to reduce the volume of the used packaging container 100, the packaging container 100 is folded in half. The way of applying force when folding the packaging container 100 in half is arbitrary. For example, as shown in Fig. 3(a), place hands on both sides of the packaging container 100 respectively, apply one finger F1 to the recessed portion 151 on the back surface of the upwardly bulging portion 150, and apply the other finger F2 near the flange portion 140. Then, as shown in Fig. 3(b), apply force so that the bottom surface 110 of the packaging container 100 becomes a valley fold. Note that a finger-hooking portion 153 protruding downward from the recessed portion 151 is provided in a part of the recessed portion 151 so that the finger F1 can be hooked. And the length L1 from the joining portion 152 to the finger-hooking portion 153 is larger than the length L2 from the joining portion 152 to the folding portion 160.

[0031] As shown in Fig. 3(b), when the bottom surface 110 of the packaging container 100 becomes a valley fold, the joining portions 152 on both sides of the folding portion 160 come into contact with each other and are in a state of being pressure-bonded. And in this state, when further force is applied in the direction in which the bottom surface 110 of the packaging container 100 becomes a valley fold, with the joining portion 152 as a fulcrum, a stress N is applied to the end 165 side of the folding portion 160 so as to tear the folding portion 160 to both sides. Then, a stress N in a direction away from each other is applied to the ends 165 on both sides, and the folding portion 160 is strongly bent and unfolded in the direction opposite to the opening direction. As a result, it undergoes plastic deformation (irreversible deformation) to such an extent that the folding portion 160 cannot return to its original shape. Also, depending on the material of the packaging container 100 and the way of applying force, when a stress N in a direction away from each other is applied to the ends 165 on both sides, the folding portion 160 is torn and cracked.

[0032] Thus, the packaging container 100 of the present invention is easily plastically deformed to such an extent that the folded portion 160 cannot return to its original shape, or the folded portion 160 is easily torn and cracked. Therefore, the packaging container 100 can easily maintain the state of being folded in half and reduced in volume. Further, since the joining portion 152 is provided at a position symmetric with respect to the center line P1 with the folded portion 160 as the center line, stress is evenly applied to both sides of the folded portion 160, and the folded portion 160 can be effectively deformed.

[0033] Further, as shown in FIG. 3(b), since the inclined surfaces 154 of the joining portion 152 are in surface contact with each other, the force from the finger can be firmly received and transmitted, and the joining portion 152 functions as a fulcrum for effectively applying the external stress N in a stable state.

[0034] In addition, since the groove 163 of the folded portion 160 has a concave shape that opens downward, moisture from food or the like accommodated on the bottom surface 110 of the packaging container 100 does not accumulate in the groove 163. Therefore, as shown in FIG. 3(b), even when the folded portion 160 is torn when the bottom surface 110 is valley-folded, it is possible to prevent moisture or the like accumulated in the groove 163 of the folded portion 160 from scattering around.

[0035] Furthermore, since the length L1 from the mating portion 152 to the hooking portion 153 is greater than the length L2 from the mating portion 152 to the folding portion 160, by the principle of the lever (the first type of lever principle) composed of the hooking portion 153 which is the force application point where force is applied from the finger, the mating portion 152 which is the fulcrum, and the folding portion 160 which is the point of action, a large stress N for bending the folding portion 160 can be exerted with a small force applied from the finger. Although the length L1 from the mating portion 152 to the hooking portion 153 is greater than the length L2 from the mating portion 152 to the folding portion 160, it is not limited to this, and the length L1 from the mating portion 152 to the hooking portion 153 and the length L2 from the mating portion 152 to the folding portion 160 can be arbitrary lengths. And no matter what sizes these lengths are, since the structure of the packaging container 100 of the present invention can utilize the principle of the lever (the first type of lever principle), with the mating portion 152 as the fulcrum, stress can be effectively applied to the folding portion 160 to bend the folding portion 160.

[0036] Note that the packaging container of the present invention is not limited to the above embodiments, and various modifications and combinations are possible within the scope described in the claims and the scope of the embodiments, and these modifications and combinations are also included in the scope of the right.

Claims

1. A packaging container comprising a bottom surface and side walls extending upward from the bottom surface, wherein the bottom surface is provided with a folding portion configured to be able to fold the bottom surface into a valley fold, and the bottom surface is provided with a mating portion at a position symmetric with respect to a line centered on the folding portion, the mating portion being configured to be able to contact each other when the bottom surface is folded into a valley fold, the folding portion being a groove, the groove being recessed so as to open downward, and the opposite surface of the bottom of the groove protruding upward, the mating portion comprising an inclined surface inclined along an extension line extending from the center of the folding portion, a packaging container characterized by this.

2. The packaging container according to claim 1, characterized in that it is made of a foamed synthetic resin.

3. The packaging container according to claim 1, characterized in that the bottom of the groove is thinner than other parts of the groove, and the opposite surface of the bottom of the groove is formed at an acute angle.

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