JPH04118314U - foam sheet tray - Google Patents

Abstract

(57) [Summary] (with modifications) [Structure] In a thermoplastic resin sheet tray in which the side wall portion 2 and the bottom portion 1 are integrally molded, the wall thickness of the side wall portion 2 is made thinner than the wall thickness of the bottom portion 1. At the same time, the side wall portion 2 is formed with a flange 3 extending in the horizontal direction at its top, and furthermore, at least one step-like widened portion 4 is formed over its entire circumference and in parallel with the bottom portion 1. [Effect] By making the side wall thickness thinner than the bottom wall thickness and providing a step-like widening section on the side wall section, it has sufficient horizontal compressive strength without causing an unnatural appearance. Moreover, it is possible to obtain a sheet tray that does not create extra stacking space.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention can be used as a foam sheet container, especially for food items such as meat, fish, and vegetables. This invention relates to the thermoplastic resin foam sheet used.

0002

[Conventional technology]

Thermoplastic foam sheet trays are used as packaging containers for fresh foods such as meat, fish, and vegetables. B is widely used in practical applications. These sheet trays are used to store perishable foods. This is then covered and wrapped with a synthetic resin film such as polyvinylidene chloride or polyethylene. It is often commercialized in a disguise. This type of sheet tray is designed for ease of handling. A synthetic material that is often used in rectangular shapes and is usually covered in packaging. The stretching direction of the resin film is the length direction of the sheet tray, so the sheet tray It receives a lot of compressive force in the width direction in its length direction.

0003 Due to this compression, the long sidewalls in particular are pulled inward toward the center, and The bottom of the horizontal sheet tray is curved. This causes damage to the side wall. This may result in damage or loss of stability, and is also unfavorable in terms of appearance. As a means to solve these problems, we have developed a sheet tray to increase its strength. It is conceivable to increase the side wall thickness, but this would only lead to a rise in material costs. Instead of stacking sheet trays, the bulk volume increases and requires more storage space. This is not necessarily desirable. On the other hand, it has the required strength with a thinner wall thickness. For the purpose of obtaining a sheet tray, e.g. The bottom part is curved in an arc shape (Japanese Utility Model Publication No. 54-32721), the tray The side wall of A is bent in two steps, and the outer side wall is sloped more than the inner side wall (in actual use). Publication No. 54-32722) has been proposed. This thing applies pressure from the side. It exhibits strong resistance against heat and prevents deformation and damage to the tray. Alternatively, figure 3, the thickness of the side wall of the tray is thinner than the thickness of the bottom, and A projecting strip extending along the flange is formed on the outer surface of the wall (Utility Model No. 57-352) No. 06) has been proposed. This one is made by reducing the thickness of the side wall. It is possible to reduce the amount of raw materials and also to extend along the flange on the outer surface of the side wall. The tray has sufficient strength due to the effect of the protrusions.

0004

[Problem that the idea aims to solve]

This type of sheet tray has the required resistance against compression force in the width direction, as described above. At the same time, it is necessary to reduce the amount of raw materials and storage space required. From the viewpoint of miniaturization, thin wall thickness is required. The tray shaped as shown in FIG. As mentioned earlier, it satisfies the above requirements to some extent, but as shown in the figure, In other words, when trays of the same shape are stacked, the protrusions on the outer surface of the side walls will move downward. The trays come into contact with the corner of the upper flange of the tray, and the trays When trying to store a large number of trays, they can only be stacked with the distance h maintained. In this case, a considerable amount of stacking height is required.

[0005] Therefore, the purpose of the present invention is to develop a thermoplastic resin foaming system that solves the above-mentioned disadvantages. The aim is to produce thin trays using fewer raw materials. Although it can be manufactured, it has the required strength in the width direction and is compatible with each other. Thermoplastic resin sheet trays that can be stacked closely together It is intended to be used.

[0006]

[Means to solve the problem]

In order to achieve the above object, the present invention has developed a thermal A plastic foam sheet tray with side walls that are thinner than the bottom. At the same time, the side wall has at least one step-like widened part extending around its entire circumference. Discloses a foam sheet tray characterized in that it is formed in parallel with a bottom part. ,provide. The side walls are thinner than the bottom, making them more durable than conventional ones. The sheet tray is designed to reduce the amount of material and is made possible by the step-like widened section formed on the side wall. It shows sufficient resistance to the pressing force acting in the width direction. Also, the side walls are thin. This combined with the fact that the widened part is stair-like makes it possible for multiple pieces to overlap in the vertical direction. When folded together, the sheet trays can overlap in close contact with each other. , the stacking height can be lowered, resulting in a space saving effect. The top of the side wall By providing an additional horizontally extending flange on the top, it acts in the width direction. It becomes possible to provide further resistance to the pressing force applied.

[0007] The depth of the sheet tray molded product should be about 10 to 50 mm, and the thickness of the side wall should be about 1.5 mm. The width of the horizontal part above and below the stepped widening part is about 0.5 to 1.5 mm. and the distance between the upper horizontal part and the lower horizontal part of the stepped widening part is approximately 1 ．． The fact that it is formed with a thickness of 0 to 4.0 mm means that it can be used as a sheet tray for practical use. This is a preferred embodiment.

[0008] The material of the thermoplastic resin foam sheet tray that can be used in the present invention is, for example, polyester. Foam sheets made of styrene, polyethylene, polypropylene, polyvinyl chloride, etc. What can I say? Especially commonly used ones have a foaming ratio of 2 to 10 times and a thickness of 2 or more. It is a 5mm foamed polystyrene resin sheet, and the stretching direction of the sheet is the longitudinal direction of the tray. Rectangular sheet trays are suitable for this invention.

[0009]

【Example】

Hereinafter, the present invention will be explained in more detail based on examples. In addition, in the explanation, each part The thickness, angle, and other values for the minute are described, but these are just preferred examples. This is only a reference value, and the foam sheet tray of this invention has such values. It is clear that there is no limitation.

0010 FIG. 1 shows a cross-sectional view of a foam sheet tray according to the present invention. It will be illustrated The sea urchin sheet tray has a bottom part 1 with a wall thickness of about 4 mm, and a part around the bottom part 1. an integrally molded sidewall extending outwardly (preferably about 55 degrees) upwardly; 2, and the wall thickness of the side wall portion 2 is thinner than the bottom wall thickness, preferably the bottom wall thickness is thinner than the bottom wall thickness. It is formed to a thickness of 40 to 60%. In addition, the thinner the wall thickness of this side wall, Although the stacking height can be reduced, the above values are realistic due to the relationship with the overall strength. It is true. At the upper end of the side wall section 2, there is a horizontally extending horizontally outward section similar to a normal sheet tray. You may form the flange 3 which extends.

[0011] In the foam sheet tray of the present invention, at least In one place, in the case of the one shown, near the upper end of the side wall part 2, there is a step-like widened part. The portion 4 is formed over the entire circumference of the side wall portion 2 and parallel to the bottom portion 1. as illustrated In addition, the step-like widened portion 4 is located on the upper horizontal surface portion 5 located inside the sheet tray. and a lower horizontal surface portion 6 located outside the sheet tray, preferably each The width of the horizontal plane part is 30 to 40% of the wall thickness of the side wall part, and the upper and lower horizontal planes are The distance between 5 and 6 is 25 to 100% of the thickness of the bottom surface 1. This stair-like The larger the length of the above-mentioned upper and lower horizontal plane parts of the widened part 4, the better the resistance to lateral force. The resistance force increases, and the distance between the upper and lower horizontal planes 5 and 6 increases as the value increases. , it is understood that the rigidity of the entire foam sheet tray increases, but as a sheet tray, Considering practicality, the above values are realistic.

0012 In the present invention, it is formed on the side wall for the purpose of improving horizontal compressive strength. Since the widened part 4 has a stepped shape, it not only increases the strength in the horizontal direction. , when multiple identical sheet trays are stacked one on top of the other, the inner surface as shown in the diagram They can be stacked with their surfaces close together. That leaves extra space between each other. You can store more sheet trays in the same space without creating gaps. can.

[0013] In addition, it is also possible to provide multiple steps of this step-like widening part on the side wall, thereby increasing the width of the part. Furthermore, the horizontal compressive strength can be improved. The following is a comparison of an actual sheet tray created based on this invention with a conventional one. I will clarify. Using expanded polystyrene as the raw material, a sheet tray with the shape shown in Figure 1 and the following dimensions was prepared. Created.

Size of molded product: 195 x 120 x 25 mm (length x width x depth) Material used: 220 g/m ² Thickness: 1.7 mm a; Bottom thickness ---------- 4 .0 mm b; Side wall thickness ---------------------- 2.3 mm c; Side wall taper angle --- 55 degrees d; Upper and lower side wall horizontal planes Width ------- 1.1 mm e; Vertical distance between the horizontal planes of the upper and lower side walls - 3.5 mm As a comparative example, a sheet board shaped like the one shown in Fig. 2, that is, a step-like widening A sheet tray was manufactured under the same conditions as in FIG. 1 except that the portion was not formed on the side wall.

[0015] When 50 sheets of each were stacked, their height was 228 mm, and there was a wall on the side wall. The stepped widening section that was formed did not affect the stacking height. In addition, at a speed of 400 mm/min, the central part of the mouth length direction of the molded product was turned inward. When compressed by 10 mm, the repulsive force at that time, that is, the compressive strength at the mouth of the molded product is The product of the present invention showed 668g, and the comparative example showed 613g, clearly It showed an improvement in its horizontal compressive strength.

[0016]

【effect】

The wall thickness of the side wall is thinner than that of the bottom, and a step-like widened part is provided on the side wall. This allows it to have sufficient horizontal compressive strength without causing an unnatural appearance. A foam sheet tray that does not require extra stacking space can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a foam sheet tray according to the present invention;

[Fig. 2] A cross-sectional view of a conventional foam sheet tray.

FIG. 3 is a sectional view of another conventional foam sheet tray in a stacked state. 1-bottom, 2-side wall, 3-flange, 4-widening part

Claims (2)

[Scope of utility model registration request] Claim 1: A thermoplastic resin foam sheet tray having a side wall and a bottom integrally molded, the side wall being thinner than the bottom, and the side wall having at least one step. A foam sheet tray characterized in that a shaped widened portion is formed around the entire circumference and parallel to the bottom. 2. The sheet tray according to claim 1, further comprising a horizontally extending rib at the top of the side wall.