Plastic container structure

Abstract

To provide a plastic container structure that is not damaged by bending even when held in the palm.SOLUTION: In an outer peripheral edge part of an upward-opening container of a hardly broken plastic container structure molded from a polymer compound material including OPS (biaxially oriented polystyrene), the angle of a raised opening peripheral edge part on a container body side is formed at an obtuse angle with an easy-to-bend fold, and a protruding length of the outermost end edge part located at the outermost end part of a horizontal peripheral body that extends horizontally from an outer lower end edge of the raised opening peripheral edge part is approximately 3 mm or more.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a plastic container structure that does not bend or break even when gripped by the palm of the hand.

Background Art

[0002] For simple plastic trays for storing salads, nigiri sushi, etc., polyethylene terephthalate (hereinafter referred to as PET) and biaxially oriented polystyrene (hereinafter referred to as OPS) are generally used as the materials.

[0003] Such PET and OPS each have their own characteristics as materials. In the case of food containers made of PET material (hereinafter referred to as PET containers), they tend to be less likely to crack against external pressure, while in the case of food containers made of OPS material (hereinafter referred to as OPS containers), they are easily cracked. However, PET containers made of PET material have a high unit price, and OPS containers made of OPS material have a low unit price, etc., and these characteristics have their advantages and disadvantages.

[0004] In addition, plastic food containers such as OPS containers are molded by minimizing waste parts in the food container in order to create food containers for the purpose of cost reduction, resource reduction, etc. Therefore, for example, the edges of food containers are made as short as possible (about 1 mm) and are generally molded (see, for example, Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, OPS containers are very brittle and will break easily if handled roughly. On the other hand, even for OPS containers with a thicker wall thickness formed to make the containers less brittle and with increased strength, when the stored item is heavy and the gravitational force applied to the OPS container becomes large, if the contents are placed on it and the upper knob is grasped, a load is applied to that part, and a phenomenon occurs where it tears more easily than the knob part.

[0007] In the present invention, for plastic containers including OPS containers, etc., the shape of the edge part of the plastic container is devised to give flexibility to the connecting part between the plastic container body and the edge part. As a result, even if the edge part is grasped or lifted, a plastic container structure is provided that is difficult to break and easy to handle.

Means for Solving the Problem

[0008] The present invention is a plastic container structure characterized in that, at the outer peripheral edge of an upward-opening container formed from a polymer compound material including an OPS (biaxially oriented polystyrene) material, the protruding length of the outermost edge portion located at the outermost end of a horizontal peripheral body extending horizontally from the lower outer edge of a raised opening peripheral edge portion is configured to be approximately 3 mm or more.

[0009] Further, the present invention is a plastic container structure that is difficult to break, characterized in that, at the outer peripheral edge of an upward-opening container formed from a polymer compound material including an OPS (biaxially oriented polystyrene) material, the raised formation angle on the container body side of the raised opening peripheral edge portion is formed into a blunt angle with a fold that is easy to bend, and includes the outermost end portion with a protruding length of approximately 3 mm or more according to claim 1.

Effect of the Invention

[0010] When a plastic container formed from a polymer compound material including an OPS material according to the present invention is used, for example, even if a heavy object is placed on the plastic container and the opposite side portions of the edge of the plastic container are grasped and lifted roughly, the force applied to the plastic container is appropriately dispersed and it does not break easily.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0012] The present invention is a plastic container structure characterized in that, at the outer peripheral edge of an upward-opening container formed from a polymer compound material containing an OPS (biaxially oriented polystyrene) material, the protruding length of the outermost edge portion located at the outermost end of a horizontal peripheral body horizontally extending from the lower outer edge of a raised opening peripheral edge portion is set to be approximately 3 mm or more.

[0013] [1. Regarding the shape according to the embodiment of the present invention] First, an embodiment of the present invention will be described. In this embodiment, a plastic food container made of a polymer compound such as OPS is targeted. In the plastic container of this embodiment, although the OPS material is mainly targeted as its material, other polystyrene containers such as HIPS (high impact polystyrene), PSP (polystyrene paper), heat-resistant PSP (heat-resistant polystyrene paper), and other polymer compound materials such as PP (polypropylene), PET, PLA (polylactic acid), etc. may also be used.

[0014] And in this embodiment, by devising the edge shape of the plastic container for an OPS material plastic container, which is a material that is relatively easy to crack and tear, the crack resistance is imparted.

[0015] Specifically, the edge shape of the plastic container will be described with reference to the drawings. FIG. 1 is a top view of a plastic container according to an embodiment of the present invention. Also, FIG. 4 is a perspective view of a plastic container according to an embodiment of the present invention and a perspective view of a cross-section of the plastic container. In FIGS. 1 and 4, the plastic container 7 is composed of an inner container 1, an inner levee 2, an inner surface inclined portion 3, an upper flat portion 4, an outer surface inclined portion 5, an outer lower edge 12, a horizontal peripheral body 6, etc. And among these parts, the outer peripheral edge portion 8 is composed of the inner surface inclined portion 3, the upper flat portion 4, the outer surface inclined portion 5, the outer lower edge 12, and the horizontal peripheral body 6. Also, the upper opening 9 refers to the opening at the upper part of the plastic container 7, and the outermost edge portion 10 refers to the outermost side of the outer peripheral edge portion 8.

[0016] The outer peripheral edge portion 8 will be described in more detail with reference to FIGS. 2 and 3. FIG. 2 is a front view of the plastic container 7 in FIG. 1 as viewed from the front. Further, FIG. 3 is a longitudinal sectional view of the food container in FIG. 1. In both FIGS. 2 and 3, the outer peripheral edge portion 8 is composed of an inner container surface inclined portion 3, an upper flat portion 4, an outer container surface inclined portion 5, an outer lower end edge 12, and a horizontal peripheral body 6. Further, the raised opening peripheral edge portion 11 is a portion having a raised shape formed by the inner container surface inclined portion 3, the upper flat portion 4, and the outer container surface inclined portion 5. And in the embodiment of the present invention, the outer peripheral edge portion 8 has a characteristic structure different from the prior art. That is, first, the edge bending portion 3a is a portion connecting the inner container surface inclined portion 3 and the upper flat portion 4. And from the inner container surface inclined portion 3 to the upper flat portion 4, the edge bending portion 3a has a bent structure so that the upper flat portion 4 is substantially parallel to the horizontal plane. Since the edge bending portion 3a has such a structure, with respect to the outer container surface inclined portion 5 and the horizontal peripheral body 6 which are further external structures of the container of the edge bending portion 3a, when a force in the gravitational direction such as pushing by hand from above is applied to the outer container surface inclined portion 5 and the horizontal peripheral body 6, the portion including the upper flat portion 4, the outer container surface inclined portion 5, and the horizontal peripheral body 6 bends downward in the gravitational direction with only the edge bending portion 3a as a fulcrum (FIG. 5b). That is, by pre-bending and molding such an edge bending portion 3a to have a structure that is more easily bent than other portions, the plastic container can be made less likely to break and have a highly flexible structure.

[0017] Further, the upper flat portion 4 is a surface substantially parallel to the horizontal plane, but has a simple flat structure. That is, ribs or the like are not provided at such a portion. By having such a simple flat structure, for example, when a downward force in the gravitational direction is applied to the outer container surface inclined portion 5 or the horizontal peripheral body 6, the force is directly transmitted to the edge bending portion 3a without an excessive force being applied to the upper flat portion 4. Therefore, cracking or the like at the upper flat portion 4 can be prevented, and the plastic container 7 has flexibility.

[0018] Also, no ribs or the like are provided on the outer container inclined portion 5 connected to the upper flat portion 4, similar to the upper flat portion 4. With such a structure, when a downward force in the gravitational direction is applied to the outer container inclined portion 5 or the horizontal peripheral body 6, the force is directly transmitted to the edge bending portion 3a.

[0019] Also, the horizontal peripheral body 6 is a portion that is located at the outermost part of the outer peripheral edge 8 and is substantially parallel to the horizontal plane. As the protruding length of the outermost edge portion 10 of the horizontal peripheral body 6 that is substantially parallel to the horizontal plane, the horizontal peripheral body 6 has a length of approximately 3 mm from the outer lower edge 12. In a conventional plastic container, the protruding length of the outermost end portion of such an edge is approximately 1 mm, which is very short compared to the plastic container of the present embodiment. The reason for this is that, as described above, in a plastic food container, it is desired to eliminate unnecessary parts as much as possible. That is, since such a horizontal peripheral body 6 is generally considered by those skilled in the art to be a portion without particular meaning, designing such a portion to be short leads to resource reduction and cost reduction. However, in the plastic container of the present embodiment, a length of approximately 3 mm is ensured as the protruding length of the outermost edge portion 10 of such a horizontal peripheral body 6. And by adopting such a shape, flexibility is given to the plastic container. Specifically, for example, when one of the corners of the edge of the plastic container is lifted upward, when the plastic container is lifted, a force in the gravitational direction is applied near the handle of the corner of the edge. At this time, by ensuring a sufficient length of the outermost end portion of the edge, the force does not stay only near the handle of the corner of the edge, and the force is dispersed over a wide range. For this reason, the force does not concentrate at one location near the handle, and cracking at such a portion can be prevented.

[0020] As another example of a mechanism for preventing such cracking, as shown in FIGS. 5(a) and 5(b), when holding the plastic container by pinching both opposing side portions at the edge of the plastic container with one hand, this also applies when lifting the plastic container. That is, with an article placed inside the food container, when lifting the plastic container by pinching both opposing side portions at the edge of the plastic container with one hand, hold it in a manner that lightly grips and holds it so as not to release the plastic container as much as possible. A force is applied from the hand toward the inside of the plastic container from both opposing side portions at the edge of the plastic container (FIG. 5(a)). And at the vicinity of the handle which is the portion holding the plastic container, a force applied to the inside of the plastic container at the fingers holding it due to gripping the plastic container and an outward force that tries to return due to the stress of the plastic container are generated. At this time, if the protruding length of the outermost edge portion 10 of the horizontal peripheral edge body 6 is approximately 1 mm as in the prior art, the force applied inward and the stress applied outward as forces concentrate near the handle, and it will easily crack. On the other hand, if the protruding length of the outermost edge portion 10 of the horizontal peripheral edge body 6 of the plastic container is approximately 3 mm, the force applied inward in the vicinity of the fingers holding it when gripping is reduced by the repulsive force of the horizontal peripheral edge body 6 itself. Also, when gripping, the force applied inward does not concentrate near the fingers holding it, and the force is appropriately dispersed. Further, with the edge bending portion 3a as a fulcrum, the outer peripheral edge portion 8 bends appropriately until a balance with the gripping force is achieved (FIG. 5(b)). For this reason, although the entire outer peripheral edge portion 8 of the plastic container bends with the edge bending portion 3a as a fulcrum, it has a structure that is not easily cracked without the force concentrating at one point.

[0021] As another example of a mechanism for preventing such cracks, as shown in FIGS. 5(c) and 5(d), when the opposite sides of the edge of the plastic container 7 are pinched with one hand and the plastic container 7 is lifted, it also applies. That is, when the plastic container 7 is grasped and lifted as shown in FIG. 5(c), as shown in FIG. 5(d), with the edge bending portion 3a as a fulcrum, the outer peripheral edge portion 8 is deformed and the horizontal peripheral body 6 is pulled upward. Here, since the protruding length of the outermost edge portion 10 of the horizontal peripheral body 6 in the present embodiment is approximately 3 mm, even if the horizontal peripheral body 6 is caught by a finger, the horizontal peripheral body 6 does not easily crack. If such a horizontal peripheral body 6 is approximately 1 mm as in the prior art, a large force is applied to the narrow region of the horizontal peripheral body 6 where the finger is placed, so the horizontal peripheral body 6 will crack.

[0022] Note that the protruding length of the outermost edge portion 10 of the horizontal peripheral body 6 in the present embodiment is approximately 3 mm, but in practice, it may be approximately 3 mm or more, and even in such a case, it is understood to belong to the same technical scope as the present embodiment.

[0023] Also, the approximately 3 mm which is the protruding length of the outermost edge portion 10 of the horizontal peripheral body 6 in the present embodiment does not depend on the shape of the plastic container 7 having the outer peripheral edge portion 8 including such a horizontal peripheral body 6. That is, such a plastic container 7 may be a square type or a disc shape, and its form does not matter from a shallow one for sushi to a deep one. Also, regardless of the size of the plastic container 7, it may be a substantially cubic salad container of approximately 150 mm in length × approximately 150 mm in width × approximately 150 mm in depth, or a circular plastic container with a diameter of approximately 300 mm such as a container for nigiri sushi. Even in such a form, the protruding length of the outermost edge portion 10 of the horizontal peripheral body 6 is approximately 3 mm.

[0024] Also, ribs or the like may be provided on the horizontal peripheral body 6 in the present embodiment. The provision of ribs or the like on such a horizontal peripheral body 6 does not have a great influence on the ease of cracking of the aforementioned plastic container 7.

[0025] [2. Operational Effects according to Embodiment of the Present Invention] Next, the effects of the embodiment of the present invention will be described. As described above, the shape of the plastic container of this embodiment is a shape that is difficult to break, and it is very convenient. The fact that it is difficult to break and there is little risk of fragments of the plastic container flying around is a very excellent advantage for such plastic containers that are used to hold sushi ingredients, corn, salad, etc.

[0026] Also, in plastic containers, from the viewpoints of weight reduction, resource reduction, etc., the use of plastics and the like should be minimized as much as possible. That is, it is common practice for the edge of the outermost end of a plastic container, which was originally considered meaningless, to be about 1 mm, and this embodiment ensures sufficient crack resistance only by deliberately extending the edge of such an outermost end. In this regard, this embodiment can be easily carried out with only a slight modification of the mold during molding, and it is excellent in convenience.

[0027] Moreover, in the plastic container of this embodiment, in order to impart crack resistance to the plastic container, no special treatment such as adding a new additive to the material is required, and it is only necessary to extend the horizontal peripheral body 6. In this regard, this embodiment is a means that can achieve low cost when imparting crack resistance to a plastic container.

[0028] The embodiments described above are merely examples. Needless to say, inventions that are presumed to belong to the category of the same technical idea are considered to be inventions belonging to the present invention.

Explanation of Reference Numerals

[0029] 1 Inside of the container 2 Inner dike 3 Inclined portion of the inner surface of the container 4 Upper flat portion 5 Inclined portion of the outer surface of the container 6 Horizontal peripheral body 7 Plastic container 8 Outer peripheral edge portion 9 Upper opening 10 Outermost edge portion 11 Opening peripheral edge portion 12 Outer lower edge

Claims

1. At the outer peripheral edge of an upward-opening container molded from a polymer compound material, including an OPS (biaxially oriented polystyrene) material, a plastic container structure characterized in that the protruding length of the outermost edge portion located at the outermost end of a horizontal peripheral body extending horizontally from the outer lower end edge of a raised opening peripheral edge portion is set to be approximately 3 mm or more.

2. At the outer peripheral edge of an upward-opening container molded from a polymer compound material, including an OPS (biaxially oriented polystyrene) material, the raised formation angle on the container body side of the raised opening peripheral edge portion is formed into an obtuse angle with a fold that is easy to bend, including the outermost end portion with a protruding length of approximately 3 mm or more according to Claim 1, and having a structure including a plastic container structure that is difficult to crack.

Images