Food container
A non-foamed thermoplastic resin container with a mesh-like insulating structure effectively addresses the insulating inadequacies of resin containers, providing superior heat insulation and ease of handling for hot foods.
Patent Information
- Application Number
- JP2024100628
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2026-01-08
AI Technical Summary
Containers made of resin with a concave-convex pattern for heat insulation do not provide sufficient insulating performance, making them difficult to handle when containing hot food.
A food container made of non-foamed thermoplastic resin with a heat insulating portion featuring convex ribs and concave grooves in a mesh-like pattern, where most of the food is supported by the ribs and minimal contact is maintained with the flat surface to reduce heat transfer.
The container achieves excellent heat insulation and ease of handling with bare hands by minimizing direct contact with hot surfaces, ensuring stable support and reduced heat transmission.
Smart Images
Figure 2026002548000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a container used for packaging food, and in particular to a container that can be suitably used for packaging cooked food such as cooked rice, side dishes, noodles, etc. [Background technology]
[0002] Conventionally, transparent containers made of non-foaming materials have been widely used as containers for packaging food (food containers) because they allow the food contained in the container to be seen from the outside and are easy to recycle. However, containers made of non-foaming materials that contain food that is hot immediately after cooking or that has been heated in a microwave oven are hot and difficult to hold with bare hands, making them difficult to handle. To solve this problem, for example, as shown in Figures 1 and 2 of Patent Document 1, a container has been disclosed that has improved heat insulation properties by being embossed with a concave-convex pattern. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-203455 Summary of the Invention [Problem to be solved by the invention]
[0004] However, the above-mentioned containers are made of paperboard, which is originally a highly insulating material, and containers in which this paperboard is replaced with resin have the problem that simply embossing the container with a concave-convex pattern does not provide sufficient insulating performance.
[0005] Therefore, an object of the present invention is to provide a food container that uses a non-foamed thermoplastic resin, has excellent heat insulation properties, and is easy to handle with bare hands. [Means for solving the problem]
[0006] In order to solve the above problems, one aspect of the present invention is a food container comprising: A food container having a bottom surface and a side wall extending upward from a peripheral edge of the bottom surface, A heat insulating portion is provided on at least a part of the bottom surface portion, The heat insulating portion includes a flat portion, a convex rib formed to protrude upward from the flat portion, and a concave groove formed to protrude downward from the flat portion, The convex rib is formed in a net shape in a plan view, The planar portion is formed within each mesh surrounded by the protruding rib, The recessed grooves are formed in a plurality of spaces apart from each other on the flat surface portion. It can be configured as follows.
[0007] The size of each mesh is 0.6 cm 2 ~6.5cm 2 It may also be possible to use the following.
[0008] The height of the protruding rib may be 0.4 mm to 2.6 mm, and the absolute value of the depth of the recessed groove may be smaller than the absolute value of the height of the protruding rib.
[0009] The depth of the recessed groove may be 0.2 mm to 1.6 mm.
[0010] The protruding rib may be formed in a lattice shape in a plan view. [Effects of the Invention]
[0011] According to the above-described embodiment, most of the food placed on the insulating portion of the food container is supported by the convex ribs, which are formed in a mesh-like shape in a plan view, and the rest is supported by the flat portion. When the insulating portion of the container is held with bare hands, the fingers directly come into contact with the lower end of the groove. In other words, in the insulating portion, the food is supported by the convex ribs and flat portion, which are formed at positions gradually spaced apart from the lower end of the groove, so heat is less likely to be transmitted to the lower end of the groove. Therefore, even if the food is hot, the lower end of the groove does not heat up, resulting in a food container with excellent insulation properties and easy handling with bare hands. [Brief explanation of the drawings]
[0012] [Figure 1] FIG. 1 is a plan view showing a food container according to an embodiment of the present invention; [Figure 2] Cross section AA of Figure 1 [Figure 3] Enlarged view of the area R1 enclosed by the two-dot chain line in Figure 1 [Figure 4] Enlarged cross section of Figure 3 [Figure 5] Enlarged cross section of CC in Figure 3 [Figure 6] FIG. 10 is an enlarged plan view of one mesh showing a modified example of the groove; [Figure 7] Enlarged cross section of Fig. 6 (DD) DETAILED DESCRIPTION OF THE INVENTION
[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a plan view showing a food container in this embodiment, Fig. 2 is a cross-sectional view taken along line AA in Fig. 1, Fig. 3 is an enlarged view of region R1 surrounded by a two-dot chain line in Fig. 1, Fig. 4 is an enlarged cross-sectional view taken along line BB in Fig. 3, and Fig. 5 is an enlarged cross-sectional view taken along line CC in Fig. 3.
[0014] As shown in Figures 1 to 5, food container 1 of this embodiment is formed by molding a non-foamed thermoplastic resin sheet. Food container 1 has an opening at the top and is formed in the shape of a roughly rectangular tray in a plan view when food container 1 is viewed downward from above, and includes a bottom surface 2 and side wall portions 3 that extend upward from the peripheral edge of bottom surface 2. Food container 1 also has flange portions 4 that protrude horizontally outward from the upper ends of side wall portions 3. Flange portions 4 are formed around the entire periphery of side wall portions 3.
[0015] As shown in FIG. 1 , an insulating section 5 having an insulating structure that prevents heat from food contained in the food container 1 from being transferred to the outside of the container is formed in an area R2 of the bottom surface 2 surrounded by a two-dot chain line. The insulating section 5 may be formed on at least a portion of the bottom surface 2. That is, the insulating section 5 may be formed on the entire bottom surface 2, or may be formed only on a portion of the bottom surface 2 that is likely to be touched by fingers when the food container 1 is held with bare hands. In this embodiment, the insulating section 5 is formed in the center of the bottom surface 2, and a peripheral groove 6 is formed around the insulating section 5. The side wall 3 is connected to the peripheral groove 6.
[0016] The heat insulating section 5 includes a flat section 7, convex ribs 8 formed to protrude upward from the flat section 7, and concave grooves 9 formed to protrude downward from the flat section 7. The convex ribs 8 are formed in a net-like shape in a plan view. Here, the convex ribs 8 being formed in a net-like shape means that a plurality of linear convex ribs extending in different directions in the horizontal direction are connected to form a plurality of closed regions R3 (mesh 11).
[0017] The shape of the mesh 11 is polygonal in plan view. The mesh 11 formed in the heat insulating section 5 may all have the same shape, or may have two or more different polygonal shapes. Specific mesh shapes include a honeycomb shape in which all the mesh 11 are hexagonal, and a lattice shape in which all the mesh 11 are square. In particular, when the protruding ribs 8 are formed in a lattice shape, the container has excellent formability and strength. In this embodiment, the protruding ribs 8 are formed by intersecting a plurality of linear ribs parallel to one direction and a plurality of linear ribs parallel to the one direction, so that the mesh 11 is formed in a square lattice shape in plan view.
[0018] The size of the mesh 11 may be appropriately determined according to the food to be stored. 2 It should be more than 1.0cm 2 This makes it possible to secure a space for forming the flat surface portion 7 and the recessed groove 9. The size of the mesh 11 is preferably 6.5 cm or more. 2 The following is sufficient: 5.0cm 2It is preferable that the following is satisfied: This allows most of the food to be supported by the convex ribs 8 without coming into contact with the flat portion 7.
[0019] The proportion of food placed on the insulating section 5 that is in contact with the flat section 7 can be determined as follows. That is, after placing edible heated food in the food container 1 and leaving it for 5 minutes, when the food placed on the insulating section 5 is viewed from above, the proportion of the area of the food that is in contact with the flat section 7 relative to the area occupied by the food can be determined. The lower this proportion, the higher the insulating properties. Specifically, the proportion should be 30% or less, preferably 20% or less, and more preferably 10% or less.
[0020] The height T1 of the protruding rib 8 refers to the vertical distance from the surface of the flat portion 7 to the top end of the protruding rib 8. The height T1 of the protruding rib 8 may be 0.4 mm or more, preferably 0.8 mm or more, and more preferably 1.2 mm or more. This reduces the proportion of food in contact with the flat portion 7, thereby improving heat insulation. However, from the perspective of moldability of the container 1, the width W1 of the protruding rib 8 must be increased in proportion to the height T1 of the protruding rib 8. If the width W1 of the protruding rib 8 is too wide, fingers may come into direct contact with the backside of the protruding rib 8, increasing the risk of feeling hot. Therefore, the height of the protruding rib 8 may be 2.6 mm or less, preferably 2.2 mm or less, and more preferably 1.8 mm or less.
[0021] From the viewpoints of formability and heat insulation, it is preferable that the distance between both side walls formed at both ends in the width direction of the convex rib 8 is narrower toward the upper end of the convex rib 8. Specifically, the cross-sectional shape of the convex rib 8 can be formed into an arc shape, an inverted U shape, an inverted V shape, a trapezoid shape, or other shapes. When the cross-sectional shape of the convex rib 8 is an inverted V shape or a trapezoid shape, it is preferable that the corners are edgeless and rounded from the viewpoint of formability.
[0022] In the heat insulating section 5, the flat surface 7 and the grooves 9 are formed in the areas other than the convex ribs 8, i.e., in the region R3 within each mesh 11 surrounded by the convex ribs 8. The flat surface 7 is a surface that extends horizontally. The depth D2 of the grooves 9 means the vertical distance from the surface of the flat surface 7 to the bottom end of the groove 9. It is preferable that the absolute value of the depth D2 of the grooves 9 is smaller than the absolute value of the height T1 of the convex ribs 8.
[0023] That is, since most of the food is held on the net-like convex ribs 8, the amount of heat transferred to the flat portion 7 is not large. Therefore, good thermal insulation is achieved even if the absolute value of the distance from the flat portion 7 to the lower ends 9a of the grooves 9 is smaller than the absolute value of the distance from the flat portion 7 to the upper ends of the convex ribs. Furthermore, by making the absolute value of the depth of the grooves 9 smaller than the absolute value of the height of the convex ribs 8, many grooves 9 can be arranged closely within each mesh 11. As a result, when the heat insulating portion 5 is held from the bottom side with fingers, the fingers come into contact with the lower ends 9a of the grooves 9, but are prevented from coming into contact with other parts, thereby improving thermal insulation.
[0024] The depth D2 of the groove 9 may be 0.2 mm or more, preferably 0.3 mm or more, and more preferably 0.4 mm or more. This prevents fingers from coming into contact with portions of the groove 9 other than the lower end 9a when holding the heat insulating portion 5 from the bottom side, thereby improving heat insulating properties. However, from the perspective of container formability, the width W2 of the groove 9 must be increased in proportion to the depth D2 of the groove 9. If the width W2 of the groove 9 is increased, the distance between the lower end portions 9a of the groove 9 increases, allowing fingers to come into contact with portions of the groove 9 other than the lower end 9a. This also creates a risk of food becoming trapped in the groove 9. This creates a risk of fingers holding the heat insulating portion 5 feeling hot. Therefore, the depth D2 of the groove 9 may be 1.6 mm or less, preferably 1.2 mm or less, and more preferably 0.8 mm or less.
[0025] From the viewpoints of formability and heat insulation, it is preferable that the groove 9 has a shape in which the distance between both side walls formed at both ends in the width direction narrows toward the lower end 9a of the groove 9. Specifically, the groove 9 can be formed to have a cross-sectional shape such as an arc shape, a U-shape, a V-shape, an inverted trapezoid shape, etc. When the cross-sectional shape of the groove 9 is a V-shape or an inverted trapezoid, it is preferable that the corners be edgeless and rounded from the viewpoint of formability. In this way, the shape of the lower end 9a of the groove 9 is linear or band-like.
[0026] In the groove 9, it is preferable that the distance between opposing side walls is narrower toward the lower end, and this also applies to both side walls formed at both ends in the longitudinal direction. Thus, the ratio of the area of the lower end 9a to the area of one groove 9 (area in plan view) can be increased as the ratio (L2 / W2) of the length L2 of the groove 9 to the width W2 of the groove 9 increases. L2 / W2 should be 1.5 or more, preferably 2.0 or more, and more preferably 2.5 or more.
[0027] A plurality of grooves 9 are formed at a distance from one another within mesh 11 (flat surface portion 7). The arrangement of the plurality of grooves 9 is not particularly limited. However, by arranging the plurality of grooves 9 closely within mesh 11, when heat-insulating portion 5 of food container 1 is held with bare hands, fingers do not come into contact with flat surface portion 7, thereby further improving heat insulation.
[0028] Specifically, it is preferable that the multiple grooves 9 are arranged in the width direction at intervals so as to be parallel to the length direction. The interval between adjacent grooves 9, 9 may be 0.2 mm or more, preferably 0.3 mm or more, and more preferably 0.4 mm or more. The interval may be 1.2 mm or less, preferably 1.0 mm or less, and more preferably 0.8 mm or less. The multiple grooves 9 may be arranged in a single row at intervals in the width direction, or in multiple rows at intervals in the length direction. The grooves 9 may be formed in a straight shape in a plan view, or in a wave-like, zigzag, curved, or other shape.
[0029] In the food container 1 configured as described above, most of the food placed on the insulating portion 5 is supported by the convex ribs 8, and the rest is supported by the flat portion 7. That is, in the insulating portion 5, the convex ribs 8 are formed in a net-like shape, so that although the contact area with the food is small, the food can be stably supported. Furthermore, the convex ribs 8 and the flat portion 7 are formed in stages at positions away from the lower ends 9a of the grooves 9, so heat is less likely to be transmitted to the lower ends 9a of the grooves 9. Therefore, even if the food is hot, the lower ends 9a of the grooves 9 do not heat up, making it possible to obtain a food container that is easy to handle with bare hands.
[0030] In the present disclosure, the food contained in the food container 1 is preferably a solid food. Here, solid food refers to food that, when left standing for 5 minutes in a heated, edible state, does not separate from the solid, or if it does, only a small amount of liquid separates. Specific examples include rice dishes such as cooked rice and sticky rice; dry noodles such as yakisoba, yakisoba noodles, pasta, and harusame; and prepared foods. Among the above solid foods, noodles can be efficiently supported on the net-like convex ribs 8, making them suitable for food to be contained in the food container 1. In other words, the food container 1 is suitable as a noodle packaging container. The food container 1 may be used to contain heated food immediately after cooking and to be eaten, or it may be used to contain products that are stored in a frozen or refrigerated state and then heated in a microwave oven before being eaten.
[0031] When the solid food is left to stand for 5 minutes in an edible heated state, the liquid content that separates from the solid content should be 10% by mass or less of the total solid food, preferably 8% by mass or less, and more preferably 6% by mass or less. If the liquid content is within the above range, the grooves 9 will not be filled with the liquid that has separated from the solid content and flowed down, and a decrease in heat insulating properties can be suppressed.
[0032] As described above, the food container 1 is formed by using a molding method such as vacuum forming, pressure forming, vacuum pressure forming, or press molding of a non-foamed thermoplastic resin sheet. Examples of resin components of the resin composition constituting the thermoplastic resin sheet include polyolefin resins such as polypropylene and polyethylene, polyester resins such as polyethylene terephthalate, and copolymers of olefins with other monomers. The thermoplastic resin sheet may be made of a single resin component or a mixture of two or more resin components. The resin composition may contain additives such as antioxidants, colorants, UV absorbers, antistatic agents, plasticizers, and lubricants, as needed.
[0033] Furthermore, in order to obtain excellent cold resistance and strength, an inorganic filler may be contained in the resin composition. Examples of inorganic fillers include talc, kaolin, mica, silica, calcium carbonate, and calcium sulfate. In this case, the resin component to be mixed with the inorganic filler is preferably a polyolefin resin such as polypropylene. Furthermore, the thermoplastic resin sheet may have a single layer structure or a laminate structure in which multiple layers are laminated. The thickness of the non-foamed thermoplastic resin sheet is not particularly limited, but it is preferable that the thickness of the entire sheet be in the range of 150 μm to 900 μm.
[0034] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and various modifications can be made without departing from the spirit of the invention.
[0035] As shown in Fig. 3, the grooves 9 in this embodiment are rectangular in plan view, and multiple rows of grooves 9 are arranged at intervals in the width direction so that their longitudinal directions are parallel to each other. This gives the flat portion 7 a mesh (lattice) shape in plan view. Therefore, even if heated food comes into contact with the flat portion 7, the food can be stably supported while minimizing the contact area with the food. Furthermore, by reducing the opening area of each groove 9, it is possible to prevent liquid flowing down from the food from entering the grooves 9, thereby maintaining excellent heat insulation.
[0036] The grooves 9 are not limited to the above shape. For example, in region R3 of mesh 11, as shown in Figures 6 and 7, it is possible to form a row of grooves 9 each having a long, narrow rectangular shape, with a plurality of grooves 9 arranged at intervals in the width direction so that their longitudinal directions are parallel to each other. This increases the proportion of the area of the lower end 9a in the area of each groove 9 in a plan view, and also enables excellent formability and improved productivity. As mentioned above, the arrangement of grooves 9 can be determined appropriately taking into account the type of food to be stored, formability, etc.
[0037] The constituent elements disclosed in the embodiments and the above-described modified examples can be combined with each other, and by combining them, new technical features can be formed. [Explanation of symbols]
[0038] 1 Food containers 2 Bottom part 3 Side wall 4 Flange 5. Insulation section 6 Peripheral groove 7 Plane part 8 Convex rib 9 Groove 9a Lower end of groove 11 Mesh
Claims
1. A food container having a bottom surface and a side wall extending upward from a peripheral edge of the bottom surface, A heat insulating portion is provided on at least a part of the bottom surface portion, The heat insulating portion includes a flat portion, a convex rib formed to protrude upward from the flat portion, and a concave groove formed to protrude downward from the flat portion, The convex rib is formed in a net shape in a plan view, The planar portion is formed within each mesh surrounded by the protruding rib, A food container in which the grooves are formed in a plurality at intervals on the flat surface.
2. The size of each mesh is 0.6 cm 2 ~6.5cm 2 The food container according to claim 1,
3. 3. The food container according to claim 2, wherein the height of the convex rib is 0.4 mm to 2.6 mm, and the absolute value of the depth of the concave groove is smaller than the absolute value of the height of the convex rib.
4. 4. The food container according to claim 3, wherein the depth of the groove is 0.2 mm to 1.6 mm.
5. The food container according to any one of claims 1 to 4, wherein the protruding ribs are formed in a lattice pattern in a plan view.
Citation Information
Patent Citations
Drawn paper container with thermal insulation property and manufacturing method therefor
JP2004203455A