JP3060506U - Vegetable container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container for fruit vegetables made of a non-crosslinked foamed polypropylene resin which is optimal for accommodating fruit fruits having sufficient rigidity and cushioning property for automatic machine work. A fruit vegetable container molded from a non-crosslinked foamed polypropylene-based resin sheet has a spacing between adjacent storage recesses arranged with a specific regularity, specifies a density and a tensile strength of the foamed resin in a flat portion, and Since the average cell diameter and cell shape are in specific ranges, they interact with each other, and the present invention is achieved.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a container for fruits and vegetables, and more particularly, to a container for fruits and vegetables that can be suitably used for storing fruits and vegetables such as tomato, pear, pear, peach, melon, and strawberry.

[0002]

[Prior art]

 Conventionally, pulp or synthetic resin foam sheets have been used as packaging containers for storing fruits and vegetables that are easily damaged during storage or transportation, for example, fruits and vegetables such as tomato, pear, pear, peach, melon, and strawberry. A tray-shaped container having a plurality of storage recesses is generally used.

[0003] In recent years, the packaging of fruits and vegetables into packaging containers has been changing from manual work to automatic mechanical work, and as a result, the base material formed in the packaging containers has become sanitary, water-resistant and recyclable. In response to such demands, the mainstream is being changed to non-crosslinked foamed synthetic resin sheets. Among them, those using a foamed polypropylene-based resin sheet as a base material are particularly suitable for automatic machine work because of their excellent rigidity, and are being increasingly used.

[0004] However, conventional packaging containers based on non-crosslinked foamed polypropylene-based resin sheets have a certain degree of rigidity, but on the other hand, have poor cushioning properties and are not satisfactory. I couldn't say. If the density of the non-crosslinked foamed synthetic resin sheet is reduced in order to obtain a cushioning property, it cannot be avoided that the originally excellent rigidity is sacrificed.

[0005] As described above, a container having a non-crosslinked foamed polypropylene resin sheet as a base material is expected as a container for fruit and vegetables, but the surface smoothness and appearance of the container are made of a polystyrene resin as a base material. The results were inferior to containers using foam sheets.

[0006]

[Problems to be solved by the invention]

 The present invention provides a fruit container having both sufficient rigidity and a cushioning property for protecting fruits, having a smooth surface and an excellent appearance, and further providing a fruit container suitable for automatic machine work. The task is to do so.

The inventors of the present invention have conducted intensive studies to solve this problem, and as a result, the shape and heating of the container at the time of molding can be improved only by improving the physical properties of the foam sheet used for producing the container for fruit and vegetables. Depending on the conditions etc., it may be difficult to give the fruit and vegetable container, which is a molded product, sufficient rigidity and cushioning, and it is difficult to finish the product with a smooth surface and good appearance. By adjusting the arrangement of the accommodation recesses and the shape and properties of the air bubbles in the flat part to a specific value in the molded fruit and vegetable container, the non-crosslinked foamed polypropylene resin sheet has excellent rigidity and cushioning properties, and has a smooth surface and appearance. Also found that an excellent new container for fruit and vegetables could be obtained.

[0008]

[Means for Solving the Problems]

The fruit and vegetable container of the present invention is a square or rectangular fruit and vegetable container having a plurality of accommodating recesses obtained by molding a non-crosslinked foamed polypropylene resin sheet, and the distance between the adjacent accommodating recesses is 0 to 10 mm. And the plurality of housing recesses are arranged on a plurality of parallel virtual straight lines, and the plurality of housing recesses on an arbitrary virtual straight line and another virtual straight line adjacent to the virtual straight line. A plurality of storage recesses are arranged in a staggered relationship with each other, the expansion ratio of the storage recesses is 1.5 to 4 times, and one flat portion having an area of 6 cm ² or more is provided near the periphery of the container. The foamed polypropylene resin has a density of 0.025 to 0.09 g / cm ³ , a tensile strength of 8 to 15 kgf / cm ² in the flat portion, and air bubbles existing in the foamed polypropylene resin. Is the following (1) It is characterized by maintaining a shape satisfying the expressions (3) to (3).

0.2 <A / B <0.65 (1) 0.2 <A / C <0.65 (2) 0.4 <(A + B + C) / 3 <1 (3) where A is the average value of the cell diameter in the thickness direction of the foamed polypropylene resin in the flat part, and B is the cell diameter in the extrusion direction (MD direction) of the foamed polypropylene resin in the flat part. The average value and C are the average values of the cell diameter in the width direction (TD direction) of the expanded polypropylene resin in the flat portion.

[0010]

[Embodiment of the invention]

 One example of a fruit vegetable container according to the present invention is shown in FIGS. FIG. 1 is a partially cutaway front view of a fruit vegetable container according to the present invention as viewed from the horizontal direction. FIG. 2 is a plan view illustrating a plan view of the fruit and vegetable container according to the present invention.

As shown in FIGS. 1 and 2, a non-crosslinked foamed polypropylene resin sheet (hereinafter, sometimes simply referred to as “foamed polypropylene resin sheet”), which is an example of the present invention, is formed. The fruit vegetable container 10 formed by processing has a rectangular shape having a short side and a long side in a planar shape (a shape viewed from above). This fruit container 10 is a single straight line (virtual straight line) that obliquely intersects the long sides facing each other. A straight line is not actually provided in the fruit vegetable container. .. Are arranged on the other arbitrary straight lines 21, 22, 23,... Formed at equal intervals in parallel with L, and flattened other than the accommodation recesses 11. It has an important part. Among the flat portions, a portion having an area of 6 cm ² or more in the vicinity of the peripheral portion of the fruit and vegetable container is particularly referred to as a flat portion 12. The flat part 12 preferably has an area of 6 to 50 cm ² . When the area of the flat portion 12 is within the above range, the flat portion 12 has a function as a gripping portion, and the efficiency of quantitatively storing fruits and vegetables can be improved. Further, the number of the flat portions 12 is preferably two to six. It is preferable that all the accommodating recesses 11 in the container for fruit and vegetables have the same size and the same expansion ratio.

Looking at the accommodating recesses 11 in the fruit vegetable container shown in FIG. 2, a plurality of accommodating recesses 11 arranged on an arbitrary straight line and a plurality of accommodating recesses 11 arranged on another straight line adjacent to the straight line Are arranged in a staggered relationship with each other.

[0013] By the arrangement of the accommodating recess 11, the efficiency of quantitatively accommodating the fruits and vegetables accommodated therein is good, and at the same time, the effect of improving rigidity can be expected.

The number of the accommodating recesses is determined according to the type and size of the fruit to be accommodated, and is usually arbitrarily selected within the range of 6 to 32. Further, the interval between the adjacent accommodation recesses is preferably 0 to 10 mm. If the interval between the accommodating concave portions is less than 0 mm, fruits and vegetables come into contact with each other and the surface of the fruits and vegetables is damaged, which is not preferable. If the interval between the accommodating recesses exceeds 10 mm, it is not preferable because the quantitative efficiency of the fruits and vegetables to be accommodated is lowered, and the accommodating efficiency and rigidity of the container for fruits and vegetables are deteriorated. Note that the spacing of the accommodation recesses being 0 mm means that the border between the accommodation recess and the adjacent accommodation recess is at the same height (same plane) as the flat portion or at a position lower than the flat portion. State. By arranging the accommodation recesses as described above, the rigidity of the fruit vegetable container and the quantitative accommodation efficiency of fruit vegetables can be improved.

The preferable expansion ratio of the expanded polypropylene resin sheet is usually 10 to 36 times, but is not limited thereto. The thickness of the foamed polypropylene resin sheet is usually 1 to 8 mm, preferably 1 to 6 mm. When the thickness of the foamed polypropylene resin sheet is within the above range, the thickness of the flat portion of the fruit and vegetable container is uniform, the corrugate does not increase, and a fruit and vegetable container having an appropriate buffering property is favorably manufactured. Can be.

In the fruit and vegetable container according to the present invention, the characteristics of the flat portion other than the accommodation recess are important. That is, it is important that the bubbles existing in the foamed polypropylene resin in the flat portion other than the accommodation concave portion of the fruit and vegetable container keep the shape satisfying the following expressions (1) to (3).

0.2 <A / B <0.65 (1) 0.2 <A / C <0.65 (2) 0.4 <(A + B + C) / 3 <1 (3) where A is the average value of the cell diameter in the thickness direction of the foamed polypropylene resin in the flat part, and B is the cell diameter in the extrusion direction (MD direction) of the foamed polypropylene resin in the flat part. The average value and C are the average values of the cell diameter in the width direction (TD direction) of the expanded polypropylene resin in the flat portion.

The average value of the bubble diameter will be further described in detail with reference to the drawings. FIG. 3 is a cross-sectional view in the thickness direction along the extrusion direction (hereinafter referred to as the MD direction) of the expanded polypropylene resin corresponding to the flat portion of the fruit and vegetable container of the present invention, and FIG. FIG. 3 is a schematic diagram based on a microscope enlarged photograph showing a cross section in a thickness direction along a width direction (hereinafter, referred to as a TD direction) of a foamed polypropylene resin corresponding to a flat portion in a container. FIGS. 3 and 4 are used to explain the shape of the bubbles in the container for fruit and vegetables according to the present invention.

In the figure, reference numeral 1 denotes a foamed polypropylene-based resin in a flat portion of an example of a container for fruit and vegetables according to the present invention (hereinafter, this may be simply referred to as a flat portion foam), and 2 denotes a bubble. Represents each. _{a 1, a 2, a 3} , ···, is a _n each bubble diameter of 2 in the thickness direction of the flat surface portion foam _{1, b 1, b 2,} b 3, ···, b n its Resolution Re is the diameter of the bubble 2 in the MD direction of the flat portion foam 1, and c _1, c _2, c _3, · · ·, the c _n represent the diameters of the bubbles 2 in a TD direction of the flat portion foam 1 .

Here, the MD direction refers to a direction in which the flat foam 1 extruded from the extruder is extruded, and the TD direction refers to a direction perpendicular to the extrusion direction. The thickness direction, MD direction, and TD direction are orthogonal to each other. In addition, the diameter in the thickness direction, the diameter in the MD direction, and the diameter in the TD direction all use the maximum tangent interval of the tangent to each bubble. The thickness direction, MD direction, and TD direction of the foamed polypropylene resin in the flat portion of the fruit vegetable container coincide with the thickness direction, MD direction, and TD direction of the foamed polypropylene resin sheet.

The average value A of the cell diameter in the thickness direction of the expanded polypropylene resin is (a ₁ + A_Two+ A_Three+ ... + a_n) / N. The average value B of the cell diameter in the extrusion direction (MD direction) of the foamed polypropylene resin is (b₁+ B_Two+ B_Three+ ... + b_n) / N. The average C of cell diameters in the TD direction of the expanded polypropylene resin is (c₁₊c_Two+ C_Three+ ... + c_n) / N. This n indicates the number of all bubbles appearing in the cross-sectional area formed by the thickness of the flat foam and the width (5 × T) that is five times the thickness T of the foam. The unit of the diameter of the bubble is mm 2.

The above-mentioned A / B and A / C indicate the flatness of the air bubbles. In the flat foam 1 of the present invention, the effect of improving the cushioning of the container is expected because the air bubbles are somewhat flat. it can. If the values of A / B and A / C are within the range of the above expression, the shape of the air bubbles of the flat foam 1 becomes a moderately flat shape, and not only the rigidity of the flat portion having the gripping function but also the Rigidity can also be maintained, and the buffering property of the housing recess is improved in combination with the expansion ratio of the housing recess in the range of 1.5 to 4 times. Preferred values of A / B and A / C are in a range satisfying the equations (4) and (5).

0.25 <A / B <0.5 (4) 0.25 <A / C <0.5 (5)

Note that it does not mean that the diameter of each bubble satisfies the above expression for each bubble, and that the ratio of the diameter in each bubble, for example, a ₁ / b ₁ , a ₂ / b ₂ , ..., the average value of the sum of a _n / b _n is not intended to suggest that it should satisfy the above equation. As a result of measuring all the bubbles in the predetermined area, the average value of the diameters of the bubbles should satisfy the above expression.

In the present invention, if the value of the average cell diameter represented by (A + B + C) / 3 in the above formula (3) is less than 0.4, unevenness in the thickness of the housing recess as well as the flat foam is obtained. This can cause On the other hand, if the average bubble diameter exceeds 1, the container not only impairs the cushioning property but also has an undesirable appearance. A more preferable range of the value of the average cell diameter [(A + B + C) / 3] of the flat foam in order to obtain a container having excellent smoothness, rigidity and cushioning property and good appearance is 0.5. ~ 0. 9 range.

Further, when the cell shape is flat and the average cell diameter is 0.4 to 1 mm, unevenness on the surface of the container is reduced, and the container has good surface smoothness and appearance.

In the fruit vegetable container according to the present invention, the density of the expanded polypropylene-based resin in the flat portion is in the range of 0.025 to 0.09 g / cm ³ . Density is 0. If it is less than 025 g / cm ³ , it is likely to bend, and the shape retention of the vegetable container, which is a molded product, becomes insufficient due to insufficient rigidity. On the other hand, if it exceeds 0.09 g / cm ³ , the cushioning property and the lightness are insufficient, and only products that are unsuitable for uses such as a transport package for packaging a soft article such as fruit and vegetables can be obtained. The preferred range of density is 0. 028 to 0.06 g / cm ³ , and within this range, the balance between the cushioning property and the rigidity required for the fruit and vegetable container can be easily achieved.

Further, the foamed polypropylene resin in the flat portion, that is, the flat portion foam has a performance of a tensile strength of 8 to 15 kgf / cm ² . If the tensile strength is less than 8 kgf / cm ² , the vegetable container is easily bent even in the case of the above-described arrangement of the accommodating concave portion, and when the vegetable container is transported by the automatic container transporter, It is easy to cause a problem that only one of the two sucker-shaped holders is sucked and held, or even if the two sucker-shaped holders are sucked and held, the center of the fruit and vegetable container hangs down. As a result, satisfactory performance in terms of rigidity cannot be obtained. On the other hand, if it exceeds 15 kgf / cm ² , only products with insufficient cushioning properties can be obtained. Even if the tensile strength is within the range of 8 to 15 khf / cm ² , the rigidity is insufficient when the bubble shape and the bubble diameter are outside the above ranges.

The tensile modulus of the flat portion is desirably 80 to 200 kgf / cm ² . When the tensile modulus is less than 80 kgf / cm ^2, fruit vegetable container is too soft, particularly depending on the type of fruit vegetables may buffering of the accommodation recess poor, fruit vegetables vessel exceeds 200k gf / cm ² In some cases, the rigidity of the vegetable becomes too high, and especially, the absorbing property of the accommodation concave part is lost, so that the protection of fruits and vegetables cannot be sufficiently performed.

The values of the tensile strength and the tensile modulus of the flat foam tend to be lower than those of the foamed polypropylene resin sheet before molding.

Here, the tensile strength and the tensile elastic modulus are measured according to the measuring method specified in JIS K 6301, the test speed is 500 mm / min, and the test piece is measured from the flat part of the container. Use a strip with a width of 5 mm (marked line distance is 20 mm), which can be cut out sufficiently so that the length direction matches the extrusion direction. The tensile strength T (kgf / cm ² ) and the tensile modulus E (kgf / cm ² ) are determined by the following equations.

T = F / A Here, F indicates the maximum load, and A indicates the cross-sectional area of the test piece. E = Δσ / Δε Further, Δσ indicates a difference in stress in the original average cross section between two points on the straight line, and Δε indicates a difference in strain between the same two points.

In the present invention, the thickness of the flat foam is preferably 1 to 6 mm, more preferably 1 to 4 mm. If the thickness is less than 1 mm, the fruit vegetable container obtained by thermoforming the foamed polypropylene resin sheet becomes too flexible, and one end of the fruit vegetable container, particularly one of the short sides of the rectangular fruit vegetable container, is removed. If you try to hold the container for fruits and vegetables horizontally by grasping it, the container for fruits and vegetables may bend too much downward, resulting in a container for fruits and vegetables that is not practical. If the thickness exceeds 6 mm, technical effects proportional to the thickness exceeding 6 mm may not be obtained.

The expansion ratio of the accommodation recess in the fruit vegetable container is 1.5 to 4 times, and preferably 2 to 3 times. When the expansion ratio exceeds 4 times, even if the above conditions of the bubble shape and the tensile strength are satisfied, the buffering property of the accommodating concave portion becomes insufficient. Resulting in. The buffering property of the accommodating recess, which has a great effect on the protection of fruits and vegetables, is achieved when the expansion ratio is between 1.5 and 4 times and the flat part of the molded vegetable container takes the above shape. Is done.

The thickness of the housing recess, that is, the thickness of the foamed polypropylene resin forming the housing recess is preferably 1 to 5 mm, and more preferably 1 to 3 mm. It is said that if the thickness of the recess is within the above-mentioned range, it has a sufficient cushioning property, the surface of the fruit and vegetables can be protected well, and the storage space for the fruit and vegetable container can be reduced because it is not bulky. There are advantages.

In the present invention, the average value of the thickness of the housing recess is calculated from the upper end of one side wall of the housing recess to the upper end of the other side wall through the center of the bottom of the housing recess. Draw six straight lines (the straight lines in the plan view of the accommodation recess, which are curved in the vertical cross section of the accommodation recess) drawn toward each other, and the center angles are different by 30 degrees. The length of the curve as viewed from the surface) is measured at points that divide it into nine equal parts (8 points excluding both ends of each line in one storage recess; 48 points in total of 6 lines), and it is measured for all points. It is an arithmetic mean value of the values obtained by performing with respect to the accommodation concave portion. In addition, the average value of the thickness of the flat portion is a value obtained by measuring the central portion of each flat portion and arithmetically averaging these measured values. In claim 4 of the present specification, the thickness of the flat portion and the accommodation concave portion indicates an average value of the thickness.

The polypropylene resin used as the base resin for producing the container for fruits and vegetables according to the present invention is, for example, a polypropylene resin having a high melt strength described in JP-T-5-506875. Can be mentioned. The polypropylene-based resin may be used alone, or may be used by mixing with another resin if necessary. Further, a rubber component may be mixed. The polypropylene-based resin used in the present invention is preferably a non-crosslinked polypropylene-based resin from the viewpoints of imparting cushioning property and shape retention (rigidity) to a fruit container as a molded product, production cost and recyclability.

[0038] The foamed polypropylene resin sheet used in the present invention is manufactured by a known ordinary extrusion foaming method, and is a sheet for obtaining a container for fruit and vegetables having characteristics satisfying the conditions specified in the present invention. In the production of, the extrusion conditions, die structure, additive treatment, etc. are appropriately selected.

More specifically, appropriate measures such as formulation of a cell regulator, adjustment of the take-up speed of the extruded sheet, adjustment of the amount of resin discharged from the die, adjustment of the ratio between the die diameter and the mandrel diameter, and the like. Is added. In this way, it is preferable that the foamed foam of the foamed polypropylene resin sheet is previously spherical or flat.

The container for fruit and vegetables according to the present invention can be formed from the obtained expanded polypropylene-based resin sheet by thermoforming by vacuum forming or pressure forming. When the plug assist method is employed, the average thickness of the side wall of the housing recess may be insufficient. The method of forming the container for fruit and vegetables is described in more detail below.When the foamed sheet is heated and softened, and a mold having the shape of a container for fruit and vegetables is used and formed by a vacuum forming method, both ends in the width direction of the sheet are usually formed. Since it is clamped at a fixed width, only the portion located substantially on the mold recess is stretched and formed.However, by performing vacuum forming while narrowing the clamp width, the sheet is positioned on the mold recess. The periphery of the part can also be drawn into the mold recess, and the container for fruit and vegetables of the present invention can be obtained. In addition, by adjusting the shape of the male mold and female mold used for molding, the gap at the time of mold matching, molding speed, etc., and the combination of the arrangement of the accommodating recess adopted in the present invention, the physical property value of the flat part can be reduced. be changed.

[0041]

【Example】

(Examples 1 to 3, Comparative Example 1) After melt-kneading a base resin, a foaming agent, and a foam controlling agent described in detail below in an extruder, the secondary breaker shape attached to the tip of the extruder is made of resin. A die having a shape in which the flow of resin in the die is sharply narrowed at the tip of the lip is selected, and the pressure in the die is reduced to 80 kgf / cm ² or less. Was discharged onto a mandrel from an annular lip and extruded and foamed to obtain a cylindrical foam. Next, the cylindrical foam was taken out under specific conditions within a take-up speed of 25 to 35 m / min, passed over a mandrel, cut into a sheet, and opened to obtain a foamed polypropylene resin sheet. At this time, an oil temperature controller was provided in the die, and the temperature of the melt-kneaded product was accurately controlled to a specific temperature in the range of 140 to 170 ° C.

The expanded polypropylene resin sheet had an expansion ratio of 30 times and a thickness of 25 mm.

Base resin: ethylene-containing propylene-based resin (SD632 manufactured by Montell) MI: 2.0 g / 10 min. Crystallization temperature: 126 ° C. Melting point: 158 ° C. Blowing agent: butane Bubble Control agent: monosodium citrate salt Extruder: tandem extruder Formulation: The blending amounts of the foaming agent and the foam regulator with respect to 100 parts by weight of the base resin are as shown in Table 1.

Using the obtained foamed polypropylene resin sheet, a plurality of accommodation recesses are arranged on a plurality of virtual straight lines parallel to each other at equal intervals by a vacuum molding method, the distance between adjacent accommodation recesses is 6 mm, and the diameter is 6 mm. Is a 75 mm hemispherical shape, has 20 storage recesses with an expansion ratio of 2.6 times, and forms a container for fruit and vegetables (size: 430 mm long, 300 mm wide) having four flat portions with an area of 26 cm ^2. did.

From the flat part (flat part foam) of the fruit vegetable container, a test piece having the same extrusion direction and length direction was cut out, and the tensile strength and the tensile elastic modulus were measured in accordance with JIS K6301. The average values are shown in Table 2. Table 2 shows the density of the flat portion, and the average thickness of the flat portion and the accommodation recess.

In addition, a micrograph of a cross section in the thickness direction along the MD direction and the TD direction of the foamed sheet is obtained, and the thickness direction, MD direction and The diameters in the TD direction are measured and arithmetically averaged to calculate an average value A of the cell diameter in the thickness direction, an average value B of the cell diameter in the MD direction, and an average value C of the cell diameter in the TD direction. did. Table 1 shows the calculation results. The average value A of the cell diameter in the thickness direction was determined as an arithmetic average of the average values from the cross sections in the thickness direction along the MD and TD directions. It can be seen that the values of A / B, A / C and (A + B + C) / 3 obtained from these A, B and C are all within the range defined by the present invention in the examples.

The expansion magnification of the accommodation recess was obtained by dividing the surface area inside the recess by the area of the opening of the recess (the area of the hatched plane S in FIG. 2).

The rigidity, appearance, surface smoothness, and cushioning property of the fruit vegetable container were evaluated as follows, and the evaluation results are shown in Table 2.

[Evaluation of Rigidity] One flat portion at the periphery of the fruit and vegetable container is sucked by the suction cup-shaped holder of the automatic container transporter, the fruit and vegetable container is held horizontally, and the amount of bending of the fruit and vegetable container is measured. did. In Table 2, those having a deflection amount of 30 mm or more were rated as x, and those with a deflection amount of less than 30 mm were rated as o.

[Evaluation of Appearance] The fruit vegetable container was visually observed to evaluate the appearance. In Table 2, ○ indicates that the bubbles are fine and uniform, and the appearance is good, and X indicates that the bubbles are coarse and the appearance is poor.

[Evaluation of Buffering Property] In the receiving recess of the container for fruit and vegetables, a size of 20 mm × 20 mm was cut out from the center of the bottom, and compressed by a compression tester at a compression speed of 10 mm / min to 90% of the total thickness. Immediately after the release, the load was released, and then left at normal temperature for 1 day to evaluate the recovery rate of the thickness. In Table 2, ○ indicates that 70% or more was recovered from the compressed state, and × indicates that the recovery was less than 70% from the compressed state.

[Evaluation of Surface Smoothness] The surface of the fruit vegetable container was visually observed and evaluated. In Table 2, ○ indicates that there is no irregularity on the surface of the container for fruit and vegetables, and X indicates that there is irregularity on the surface of the container for fruit and vegetable.

The fruit vegetable container according to the embodiment has sufficient rigidity and is suitably used particularly for automatic machine work. Even when the fruits were stored, they did not lose their shape and could be easily lifted. The cushioning was also adequate, did not damage the soft surface of the fruit, and the appearance was good.

[0054]

[Table 1]

[0055]

[Table 2] Note: * 1: Average thickness of flat part * 2: Average thickness of accommodation recess

[0056]

[Effect of the invention]

 The container for fruit and vegetables of the present invention has a non-cross-linked foam in which the spacing between adjacent storage recesses is arranged with a specific regularity, and the flat part of the container for fruit and vegetable is characterized by specific physical properties and bubble shape. Since it is a container for fruit and vegetables made of polypropylene resin, it has sufficient rigidity, and only one of the two suction cup-shaped holders is used when the container for fruit and vegetables is transported by the automatic container transporter especially in automatic mechanical work. Even if it is held only by suction, transport trouble is less likely to occur due to less deflection. In addition, it is provided with shock absorbing properties, and can sufficiently protect fruits and vegetables. Further, since the average cell diameter is in a specific range, the appearance of the container for fruit and vegetables is very good. In addition, since the bubble shape is flat and the average bubble diameter is within a specific range, the surface of the container for fruit and vegetables is smooth without irregularities. For this reason, it is possible to satisfactorily adsorb to the sucker-shaped holder of the automatic container transporter, and it is suitable for accommodating vegetables whose surface is soft and easily damaged during handling or transportation.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a fruit vegetable container which is an example of the present invention.

FIG. 2 is a partially cutaway plan view showing a plan view of a container for fruit and vegetables which is an example of the present invention.

FIG. 3 is an explanatory view of the method for measuring the bubble diameter of the fruit and vegetable container according to the present invention, and is a cross-sectional view in the MD direction of a flat portion of the fruit and vegetable container.

FIG. 4 is an explanatory view of the method for measuring the bubble diameter of the fruit and vegetable container according to the present invention, and is a cross-sectional view in the TD direction of a flat portion of the fruit and vegetable container.

[Explanation of symbols]

1: non-crosslinked foamed polypropylene resin sheet, 2: cell, 10: fruit vegetable container, 11: accommodating recess, 12: flat portion _{a 1, a 2, a 3} , ···, a n: the bubbles in the thickness direction _{diameter, b 1, b 2, b} 3, ···, b n: cell diameter in MD _{direction, c 1, c 2, c} 3, ···, c n: TD
Diameter of bubble in direction, 21, 22, 23: straight line parallel to L, L: straight line, S: oblique line plane

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 23:00 105: 04 B29L 22:00

Claims (4)

[Utility model registration claims] 1. A container for fruit and vegetables having a plurality of recesses obtained by molding a non-crosslinked foamed polypropylene resin sheet, wherein the interval between adjacent recesses is 0 to 10 mm. The housing recesses are arranged on a plurality of parallel virtual straight lines, and a plurality of housing recesses on an arbitrary virtual straight line and a plurality of housing recesses on another virtual straight line adjacent to the virtual straight line. Are arranged in a staggered relationship with each other, the expansion ratio of the accommodation concave portion is 1.5 to 4 times, and one or more flat portions having an area of 6 cm ² or more are formed near the periphery of the container. The density of the expanded polypropylene-based resin is 0.025 to 0.09 g / c
m ³ , tensile strength is 8 to 15 kgf / cm ² , and bubbles existing in the expanded polypropylene resin are as follows (1)
A fruit vegetable container characterized by maintaining a shape satisfying formulas (3) to (3). 0.2 <A / B <0.65 (1) 0.2 <A / C <0.65 (2) 0.4 <(A + B + C) / 3 <1 (3) Where A is the average value of the cell diameter in the thickness direction of the expanded polypropylene resin in the flat portion, and B is the average value of the cell diameter in the extrusion direction (MD direction) of the expanded polypropylene resin in the flat portion. , And C are average values of the cell diameter in the width direction (TD direction) of the expanded polypropylene resin in the flat portion. ] 2. A container for fruit and vegetables according to claim 1, wherein bubbles existing in the foamed polypropylene resin in the flat portion maintain a shape satisfying the following formulas (4) to (6). 0.25 <A / B <0.5 (4) 0.25 <A / C <0.5 (5) 0.5 <(A + B + C) / 3 <0.9 ... (6) [However, A, B and C in the above formulas (4) to (6) have the same meaning as described above. ] 3. The container for fruit vegetables according to claim 1, wherein a tensile modulus of the expanded polypropylene resin in the flat portion is 80 to 200 kgf / cm ² . 4. The foamed polypropylene resin in the accommodation recess has a thickness of 1 to 5 mm, and the foamed polypropylene resin in the flat portion has a thickness of 1 to 6 mm. A container for fruits and vegetables described in 1.