Food packaging containers

Abstract

To provide a food packaging container in which heat from stored food is hardly transmitted. [Solution] A large number of bottom wall ribs and side wall ribs provided on the container body are formed at least on the bottom wall and side wall portions that may come into contact when holding the container, from the viewpoint of reinforcing the container body and suppressing heat conduction when the container body is held. The bottom wall ribs and side wall ribs are formed in a form in which bottom wall ribs 28α or side wall ribs 29α with a high height H protruding outward and bottom wall ribs 28β or side wall ribs 29β with a low height H are arranged alternately, from the viewpoint of suppressing heat conduction when the container is held.

Description

[Technical field]

[0001] The present invention relates to a food packaging container, and more particularly to a food packaging container having a container body on which a large number of ribs are formed. [Background technology]

[0002] Conventionally, widely used food packaging containers for packaging fresh fish, meat, fruits, vegetables, cooked foods, etc. include containers in which a container body made by thermoforming a thermoplastic resin sheet into a desired shape and a lid body that is removably attached to the opening of the container body are connected together via a hinge portion, and containers in which the container body and the lid body are packaged by internal or external fit-fitting.

[0003] This food packaging container is packaged, for example, by placing food or the like in the container body, folding it at the hinge portion, and fitting the lid body over the opening of the container body. The packaged containers are often stacked in multiple layers for display. For this reason, not only is a certain degree of mechanical strength required for the container body of the food packaging container, but the lid body is also required to have a mechanical strength (especially compression resistance) sufficient to prevent it from being crushed when stacked in multiple layers as described above.

[0004] Therefore, as a method for increasing the rigidity of food packaging containers thermoformed from thermoplastic resin sheets, a number of ribs are often formed on the bottom wall and side wall of the container body of the food packaging container, the top wall of the lid, etc. (e.g., Patent Documents 1 and 2, etc.). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-290728 A [Patent Document 2] Design Registration No. 1729623 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] Meanwhile, in supermarkets, convenience stores, and the like, foods such as boxed lunches, fried noodles, octopus balls, and pilaf are stored in the above-mentioned food packaging containers, heated in a microwave oven, and served to be eaten in an eat-in space, etc. In this case, the product immediately after heating in the microwave oven is difficult to hold in the hands because the container itself is hot, and the stored food may be difficult to eat. In particular, in recent years, food packaging containers have been made thinner due to consideration of environmental issues, and the heat of heated food is more easily transferred to the hands through the container.

[0007] The present invention has been made in consideration of the problems inherent in the background art described above, and has an object to provide a food packaging container that is less susceptible to the transfer of heat from the stored food. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a food packaging container as described in the following [1] to [7]. [1] A food packaging container having a container body on which a large number of ribs are formed, This food packaging container is characterized in that a large number of protruding ribs with high and low heights are formed alternately on the part of the container body that may come into contact with the container body when the container body is held by hand. [2] The food packaging container described in [1] above, characterized in that a large number of protruding ribs with high and low heights are formed in a continuous, alternating pattern on the bottom wall and side wall of the container body. [3] A food packaging container as described in [1] or [2] above, characterized in that a large number of protruding ribs with high and low heights are formed alternately on more than 80% of the bottom wall and side wall of the container body. [4] The food packaging container according to any one of [1] to [3] above, characterized in that the difference in height between the protruding ribs with higher height and the protruding ribs with lower height is 0.3 mm or more. [5] The food packaging container according to any one of [1] to [4] above, wherein the protruding, tall ribs are formed with sharp tips. [6] The food packaging container according to any one of [1] to [5] above, further comprising a lid connected to the container body via a hinge portion. [7] The food packaging container according to [6] above, characterized in that the lid is formed with an exhaust section for discharging water vapor and the like generated when the stored food is heated. Effect of the Invention

[0009] According to the food packaging container of the present invention described above, the heat of the stored food is not easily transferred, and the container can be easily held in the hands and the stored food can be eaten, even immediately after heating in a microwave oven. [Brief description of the drawings]

[0010] [Figure 1] 1 is a plan view showing one embodiment of a food packaging container according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a portion taken along line AA in FIG. [Diagram 3] 2 is a cross-sectional view showing the food packaging container shown in FIG. 1 with the lid closed. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a portion X in FIG. [Diagram 5] 1 is a cross-sectional view conceptually showing one embodiment of a rib shape formed on a food packaging container according to the present invention. FIG. [Figure 6] 10A to 10C are cross-sectional views conceptually showing various other embodiments of rib shapes formed on the food packaging container according to the present invention. [Figure 7] FIG. 2 is an enlarged perspective view of the BB and CC portions of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a food packaging container according to the present invention will be described in detail with reference to the drawings.

[0012] Figures 1 and 2 show one embodiment of a food packaging container according to the present invention, with Figure 1 being a plan view and Figure 2 being a cross-sectional view of a portion taken along line AA in Figure 1. In these figures, reference numeral 1 denotes a food packaging container, 2 denotes a container body, 3 denotes a lid, and 4 denotes a hinge portion, respectively.

[0013] The food packaging container 1 of the embodiment shown in Figures 1 and 2 is obtained by thermoforming a thermoplastic resin sheet, and has a configuration in which a container body 2 and a lid 3 are integrally connected via a hinge portion 4. The lid 3 opens and closes the upper opening of the container body 2 by rotating about the hinge portion 4 as a fulcrum.

[0014] The thermoplastic resin sheet constituting this food packaging container 1 can be a wide variety of thermoplastic resin sheets used for conventionally known food packaging containers, and may be, for example, a thermoplastic resin sheet such as a polystyrene-based resin sheet, a polyethylene-based resin sheet, a polypropylene-based resin sheet, or a polyethylene terephthalate-based resin sheet, and is not particularly limited, but a transparent thin thermoplastic resin sheet is usually used. This food packaging container 1 is produced by thermoforming (vacuum forming, pressure forming, vacuum pressure forming, hot plate forming, etc.) the thermoplastic resin sheet. The food packaging container 1 obtained by thermoforming a thermoplastic resin sheet preferably has a thickness of, for example, 150 to 500 μm, and from the viewpoint of light weight, preferably has a thickness of 200 to 400 μm. In particular, when the thickness is thin, heat is easily transmitted, and the effect of the present invention is easily obtained.

[0015] As shown in the figure, the container body 2 of the food packaging container 1 has a bottom wall 21, a side wall 22 rising from the bottom wall 21, and a body fitting portion 23 formed at the upper end of the side wall 22, i.e., at the upper opening end. In the illustrated embodiment, the container body 2 is formed in an elliptical shape in a plan view, and the side wall 22 is formed as an inclined surface that expands in a step-like manner upward from the bottom wall 21. As shown in FIG. 4, the body fitting portion 23 is formed as a step portion 23a formed to protrude outward from the upper end of the side wall 22, and a fitting surface portion 23b formed as an inclined surface that gradually approaches the inside (toward the center of the container) downward from the outer end of the step portion 23a, and is formed as a reverse tapered fitting portion that expands upward. A body flange portion 24 protruding outward is formed on the lower edge of the body fitting portion 23 formed in a reverse tapered shape.

[0016] The periphery of the body flange 24 is formed with projections and recesses 24a for the purpose of preventing slipping. The projections and recesses 24a can be formed, for example, by knurling. The body flange 24 is provided with two knobs 25 formed by protruding a part of it outward. The four corners of the bottom wall 21 are provided with anti-blocking projections 26 for preventing blocking when the containers are stacked before use, and anti-slip recesses 27 for realizing stable stacking of the containers with contents inside.

[0017] A large number of bottom wall ribs 28 and side wall ribs 29 consisting of convex stripes protruding outward (to the outside of the container) are provided on the bottom wall 21 and side wall 22 of the container body 2. In the present invention, the large number of bottom wall ribs 28 and side wall ribs 29 are provided not only to reinforce the container body 2 but also from the viewpoint of suppressing the conduction of heat when the container body 2 is held. From this viewpoint, the formation positions and formation forms of the large number of bottom wall ribs 28 and side wall ribs 29 are designed.

[0018] The numerous bottom wall ribs 28 and side wall ribs 29 provided on the container body 2 are formed at least on the portions of the bottom wall 21 and the side wall 22 that may come into contact when the container is held, from the viewpoint of reinforcing the container body 2 and suppressing heat conduction when the container body 2 is held. In the container body 2 according to the illustrated embodiment, numerous bottom wall ribs 28 and side wall ribs 29 protruding outward are formed on almost the entire area (80% or more of the bottom wall) of the bottom wall 21 except for the portion where the slippage prevention recess 27 is provided, and on almost the entire area (80% or more of the side wall) of the side wall 22. More preferably, numerous bottom wall ribs 28 and side wall ribs 29 protruding outward may be formed on 90% or more of the bottom wall 21 and 90% or more of the side wall 22. A large number of bottom wall ribs 28 extending in the vertical direction are formed on the upper end 21a and lower end 21b of the bottom wall portion 21, and a large number of side wall ribs 29 continuing to the large number of bottom wall ribs 28 extending in the vertical direction are formed on the front surface 22a and rear surface 22b of the side wall portion 22. A large number of bottom wall ribs 28 extending in the width direction are formed on the middle portion 21c of the bottom wall portion 21 excluding the upper end 21a and lower end 21b, and a large number of side wall ribs 29 continuing to the large number of bottom wall ribs 28 extending in the width direction are formed on the right side 22c and left side 22d of the side wall portion 22.

[0019] In addition, from the viewpoint of suppressing the conduction of heat when the container is held, the numerous bottom wall ribs 28 and side wall ribs 29 provided on the container body 2 are formed in a form in which bottom wall ribs 28α or side wall ribs 29α protruding outwardly and having a high height H are alternately arranged with bottom wall ribs 28β or side wall ribs 29β having a low height H, as shown in Fig. 5. The portions in which the bottom wall ribs 28α, 28β or side wall ribs 29α, 29β of different heights are alternately arranged are at least the portions of the bottom wall 21 and the side wall 22 that may come into contact when the container is held, and in the container according to the illustrated embodiment, it is considered that the entire areas of the bottom wall 21 and the side wall 22 may come into contact when the container is held, and all the ribs formed in the entire area (the numerous ribs formed on 80% or more of the bottom wall and the side wall of the container body, preferably 90% or more of the bottom wall and the side wall) are alternately arranged with the high ribs 28α, 29α and the low ribs 28β, 29β. In addition, the high ribs 28α, 29α and the low ribs 28β, 29β may be formed in an alternating arrangement, for example, as shown in FIG. 6(a), such that the high ribs 28α, 29α are positioned next to the high ribs 28α, 29α, and the low ribs 28β, 29β are positioned next to them, and this arrangement is repeated, so that the high ribs and the low ribs are formed in an alternating arrangement. Also, as shown in FIG. 6(b), the low ribs 28β, 29β are positioned next to the high ribs 28α, 29α, and the low ribs 28β, 29β are positioned next to them, and this arrangement is repeated, so that the high ribs and the low ribs are formed in an alternating arrangement. Furthermore, as shown in FIG. 6(c), the high ribs 28α, 29α and the low ribs 28β, 29β may be arranged in an alternating arrangement, two by two. In the present invention, the arrangement of the high ribs and the low ribs protruding in an alternating manner includes at least the above-mentioned four arrangements. From the viewpoint of effectively reducing the contact area when holding the container, the most preferable embodiment is one in which high ribs 28α, 29α and low ribs 28β, 29β are arranged alternately, as shown in FIG.

[0020] The height difference S between the high ribs 28α, 29α and the low ribs 28β, 29β to be formed is preferably 0.3 mm or more, more preferably 0.35 to 1.50 mm, and particularly preferably 0.4 to 1.0 mm. The width W of the ribs 28, 29 to be formed can be usually 1 to 8 mm, and preferably 2 to 5 mm. The height H of these ribs 28, 29 can be usually 1 to 8 mm, and preferably 2 to 5 mm. Furthermore, the distance L between the ribs 28, 29 can usually be 0.5 to 2.0 times the width of the rib itself. In addition, the tips of the high ribs 28α, 29α and the low ribs 28β, 29β are semicircular in FIG. 5. Alternatively, the tips may be sharpened. This makes it difficult for food to get into the tips, and heat is less likely to be transferred. For example, a sharpened tip may be a V-shape (L-shape) as shown in FIG. 6(d). The sharpened tip may be only applied to the high protruding ribs 28α, 29α that are likely to come into contact when held.

[0021] 1 and 2, the lid 3 of the food packaging container 1 comprises a top wall portion 31, a peripheral wall portion 32 hanging down from the top wall portion 31, and a lid fitting portion 33 formed on the peripheral edge of the peripheral wall portion 32. Since the lid 3 closes the upper opening of the container body 2, the shape of the lid 3 in a plan view corresponds to that of the container body 2, and therefore, in the illustrated embodiment, the lid 3 is also formed into an elliptical shape in a plan view.

[0022] The peripheral wall 32 of the lid body 3 extends from the periphery of the top wall 31 while expanding downward, and a lid fitting portion 33 is formed from the lower end of the peripheral wall 32 toward the outside. As shown in Fig. 4, the lid fitting portion 33 is formed as a downwardly tapered fitting portion consisting of an extension portion 33a formed from the lower end of the peripheral wall 32 toward the outside, and a lid fitting surface portion 33b formed as a slope gradually extending inward (toward the center of the container) from the outer edge of the extension portion 33a. A lid flange portion 34 protruding outward is formed on the lower edge of the lid fitting portion 33 formed in a reverse tapered shape.

[0023] The periphery of the lid flange 34 is formed with projections and recesses 34a for the purpose of preventing slipping. The projections and recesses 34a can be formed, for example, by knurling. The lid flange 34 is provided with two knobs 35 formed by protruding a part of it outward to facilitate removal of the lid 3. The four corners of the top wall 31 are provided with anti-blocking projections 36 for preventing blocking when the containers are stacked before use, and anti-slip projections 37 for stabilizing the stacked state of the containers with contents inside.

[0024] The top wall 31 of the lid 3 is provided with an exhaust section 38 for releasing water vapor and the like generated in the container. As shown in FIG. 7, the exhaust section 38 is formed by digging down a part of the top wall 31 to form a recess 38a, and an exhaust port 38b is formed in the recess 38a. The exhaust port 38b may have various shapes, but in the illustrated embodiment, it is formed by two U-shaped notches. In the recess 38a, a plurality of inclined grooves 38c (eight in the illustrated embodiment) are formed in a connected state to serve as escape routes for water vapor and the like, and the recess 38a is appropriately provided with a reinforcing rib 38d to prevent the exhaust port 38b, which is the U-shaped notch, from warping upward. By providing the lid body 3 in this manner, even if a packaging film or the like covers part or all of the exhaust port 38b formed in the lid body 3 during heating in a microwave oven, water vapor and the like generated inside the container can be smoothly released to the outside, thereby preventing the lid body 3 from unintentionally coming off from the container body 2, etc.

[0025] The peripheral wall 32 of the lid body 3 is provided with a large number of vertically extending lid ribs 39 for reinforcement over almost the entire area (80% or more of the peripheral wall) except for the area where the anti-slip projections 37 are formed. The large number of lid ribs 39 do not need to be arranged alternately with different protruding heights like the bottom wall ribs 28 or side wall ribs 29 provided on the container body 2 described above, but if there is a concern about heat conduction when holding the container, it is preferable to form the large number of lid ribs 39 formed in that area in a form where protruding heights are alternately arranged with high and low ribs.

[0026] The container body 2 and the lid body 3 are connected via a hinge portion 4. In the illustrated embodiment, the hinge portion 4 is formed by interposing a hinge 41 having an arc-shaped cross section between the body flange portion 24 of the container body 2 and the lid flange portion 34 of the lid body 3, and is bendable at the arc-shaped cross section hinge 41, which serves as a fulcrum when the lid body 3 is rotated toward the container body 2. The hinge 41 may have a U-shaped cross section, and may be configured to be flat in the open state and to be folded in half vertically by a folding portion (perforation portion, thin portion, etc.) in the closed state.

[0027] In the food packaging container 1 of the present invention described above, food (e.g., bento, yakisoba, takoyaki, pilaf, etc.) is placed into the container body 2, and the lid body 3 is attached to the container body 2, and the packaging process is completed by covering it with packaging film or the like as necessary. In this case, the food packaging container 1 of this embodiment is folded at the hinge portion 4 to place the lid body 3 over the upper opening of the container body 2, and the upper opening of the container body 2 is closed by the lid body 3 by externally fitting the reverse tapered lid fitting portion 33 of the lid body 3 into the reverse tapered body fitting portion 23 provided at the upper opening end of the container body 2, thereby achieving a closed state with high sealing properties and reliability.

[0028] The food packaging containers 1 in a packaged state are stacked in multiple stages and displayed. In this case, the food packaging container 1 of this embodiment has many ribs (bottom wall ribs 28 and side wall ribs 29 of the container body 2, and lid ribs 39 of the lid 3) formed on the container body 2 and the lid 3, which improves the strength and rigidity of the thermoformed container 1, making it difficult to collapse even when stacked in multiple layers. In addition, since the strength and rigidity of the thermoformed container 1 can be improved by the many ribs, it is possible to reduce the thickness of the thermoplastic resin sheet used. In addition, in the food packaging container 1 of this embodiment, anti-slip recesses 27 are formed at the four corners of the bottom wall portion 21 of the container body 2, and anti-slip protrusions 37 are formed at the four corners of the top wall portion 31 of the lid body 3, thereby enabling the containers 1 to be stacked stably.

[0029] A food packaging container 1 selected from displayed products is heated in a microwave oven while the food is still packaged and provided to a customer, who then eats the packaged food in an eat-in space or takes the container home and heats it in the microwave oven before eating. When heating in the microwave oven as described above, the food packaging container 1 of this embodiment has an exhaust section 38 formed in the top wall portion 31 of the lid body 3. Therefore, even if the food is placed in a microwave oven in its packaged state without being opened and cooked, water vapor and the like generated from the food is discharged to the outside of the container through the exhaust section 38. This effectively prevents the lid body 3 from unintentionally coming off the container body 2 due to internal pressure during or after heating, or the container itself from expanding and deforming. In addition, the container itself is hot immediately after heating in a microwave oven, but in the food packaging container 1 according to the present invention, the high-protruding ribs 28α, 29α and the low-protruding ribs 28β, 29β are alternately arranged in large numbers in the portion of the container body 2 that may come into contact when the container 1 is held by hand, so that the contact surface when the container is held by hand can be reduced and the heat transferred from the container itself can be reduced. In particular, the food packaging container 1 of this embodiment has the high-protruding ribs 28α, 29α and the low-protruding ribs 28β, 29β alternately arranged in large numbers in the bottom wall portion 21 and the side wall portion 22 of the container body 2, which is more than 80% of the entire area, so that the container can be held safely in the hand immediately after heating in a microwave oven and the stored food can be eaten.

[0030] The above describes an embodiment of the food packaging container according to the present invention, but the present invention is not limited to the above-described embodiment, and it is natural that various modifications and changes are possible within the scope of the food packaging container as the technical idea of ​​the present invention described in the claims of the utility model registration. [Industrial Applicability]

[0031] The food packaging container of the present invention can be suitably used as a food packaging container for storing foods that are heated in a microwave oven and served in supermarkets, convenience stores, etc., such as bento boxes, yakisoba, takoyaki, pilaf, etc. [Explanation of symbols]

[0032] 1 Food packaging containers 2 Container body 21 Bottom wall 21a top end 21b Bottom end 21c middle part 22 Side wall 22a front 22b Back 22c right side 22d left side 23 Body fitting part 23a Stepped section 23b Mating surface part 24 Body flange 24a Concave and convex formed by knurling 25 Knob 26 Anti-blocking protrusion 27 Anti-slip recess 28 Bottom wall rib 28α high bottom wall rib 28β Low bottom wall rib 29 Sidewall rib 29α High sidewall rib 29β Low sidewall rib 3 Lid 31 Ceiling wall 32 Peripheral wall part 33 Lid fitting part 33a Extension 33b Lid fitting surface part 34 Lid flange 34a Concave and convex formed by knurling 35 Knob 36 Anti-locking protrusion 37 Anti-slip protrusion 38 Exhaust section 38a Recess 38b Exhaust port (U-shaped notch) 38c inclined groove 38d Reinforcement rib 39 Lid Rib 4 Hinge part 41 Hinge

Claims

1. In a food packaging container having a container body on which a large number of ribs are formed, This food packaging container is characterized in that a large number of protruding ribs with high and low heights are formed alternately on the part of the container body that may come into contact with the container body when the container body is held by hand.

2. 2. The food packaging container according to claim 1, wherein a large number of the protruding ribs having high and low heights are alternately and continuously formed on the bottom wall and side wall of the container body.

3. 3. The food packaging container according to claim 1, wherein a large number of protruding ribs with high and low heights are alternately formed on at least 80% of the bottom wall and side wall of the container body.

4. 3. The food packaging container according to claim 1, wherein the difference in height between the high and low protruding ribs is 0.3 mm or more.

5. 3. The food packaging container according to claim 1, wherein the protruding rib has a sharp tip.

6. 3. The food packaging container according to claim 1, further comprising a lid connected to the container body via a hinge portion.

7. 7. The food packaging container according to claim 6, wherein the lid is formed with an exhaust port for exhausting water vapor and the like generated when the stored food is heated.

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