Shock-absorbing rib structure, pulp molded cushioning material, packaging material, and packaging system

Abstract

To provide a rib structure for impact buffering of a pulp mold buffering material which can reduce impact acceleration applied on a packaging object more than that with conventional specifications.SOLUTION: A rib structure for impact buffering of a pulp mold buffering material according to the present invention is a hollow rib structure for impact buffering which comprises a top plate and a side wall, with a bottom portion being open. In the rib structure for impact buffering, at least one opening part is provided in a range equal to or less than a half of height of the side wall, with a distance from the bottom portion to the top plate defined to be height of the rib structure for impact buffering. This configuration makes rigidity of an upper part and rigidity of a lower part of the rib structure almost the same, so as to be compatible, so that the entire rib structure can be uniformly compressed and / or collapsed.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a rib structure for impact buffering, a pulp mold buffer, a packaging material, and a packaging system.

Background Art

[0002] Towards the realization of a recycling-oriented society, reducing the usage amount of single-use plastics has been listed in the environmental management policies of various companies. Also, in recent environmental problems, in order to address issues such as marine plastic waste problems, reducing the usage amount of plastic packaging materials has been demanded. Therefore, the utility value of pulp mold packaging materials with excellent recyclability and recoverability has been increasing further.

[0003] A pulp mold buffer can buffer the impact applied to the packaged object, that is, the impact acceleration, caused by vibration and drop impacts received during the logistics process, by its own deformation and buckling actions. For example, even when an impact acceleration of up to several hundred G is applied to the packaged object, a technology is known and already implemented that can reduce it to an impact acceleration of less than 100 G by using a buffer.

[0004] The conventional pulp mold buffer 100 according to the conventional specification shown in FIG. 1 basically has a storage space 105 for the packaged object and is configured by providing an impact buffering rib structure 110 having a cylindrical or prismatic structure with an impact buffering function.

[0005] Also, for example, Patent Document 1 discloses a configuration in which a slit is provided in the packaged object receiving portion of a pulp mold buffer and is crushed so as to conform to the shape of the packaged object, thereby forming a region for accommodating the packaged object.

Summary of the Invention

Problems to be Solved by the Invention

[0006] Packaging materials for precision equipment using pulp molded cushioning material do not have very high impact resistance, and there is a risk of damage to the packaged items. Therefore, there is a need for pulp molded cushioning material to have a function that reduces impact acceleration to a smaller degree. However, the impact-absorbing rib structure of pulp molded cushioning material as described above has reached its limit in terms of reducing impact acceleration.

[0007] Therefore, the present invention aims to provide an impact-absorbing rib structure for pulp molded cushioning material that can reduce impact acceleration compared to conventional specifications. [Means for solving the problem]

[0008] The above problem relates to a pulp molded cushioning material shock-absorbing rib structure, which consists of a top plate and side walls and is a hollow shock-absorbing rib structure with an open bottom, wherein the distance from the bottom surface to the top plate is defined as the height of the shock-absorbing rib structure, and the height of the side walls is less than half of the height of the rib structure. only Within this range, at least one opening is provided, and the side wall has a slope in the height direction. Furthermore, the top plate is enclosed around its entire circumference, and the rigidity of the upper and lower parts of the impact-absorbing rib structure in the height direction are of a similar degree. This is solved by a shock-absorbing rib structure. [Effects of the Invention]

[0009] The shock-absorbing rib structure of the present invention has at least one opening in a range of half or less of the height of the side wall. As a result, the rigidity of the upper and lower parts of the rib structure are of similar proportions and consistent, so that the entire rib structure can be uniformly compressed and / or crushed. By utilizing the overall height of the rib structure as an shock-absorbing mechanism, the spring constant of the entire rib structure can be reduced, and the impact acceleration acting on the packaged object can be reduced compared to conventional specifications. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of pulp molded cushioning material according to conventional specifications. [Figure 2] This is a perspective view of the impact-absorbing rib structure according to the conventional specifications. [Figure 3]This is a schematic cross-sectional view showing the compression deformation of the side wall in a conventional design. [Figure 4] This is a graph showing the impact coefficient of the cushioning material. [Figure 5] This is a schematic cross-sectional view showing an example of clearance to prevent the bottom of the packaged item from touching the bottom. [Figure 6] This is a schematic cross-sectional view showing the sloped side wall of the shock-absorbing rib structure. [Figure 7] This is a schematic cross-sectional view showing a side wall where the peripheral length (cross-sectional area) changes. [Figure 8] This is a perspective view of a shock-absorbing rib structure according to the first embodiment of the present invention. [Figure 9] This is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in the first embodiment. [Figure 10] This is a schematic diagram showing the dimensions of an opening in the side wall. [Figure 11] This is a perspective view of a shock-absorbing rib structure according to a second embodiment of the present invention. [Figure 12] This is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in the second embodiment. [Figure 13] This is a perspective view of a shock-absorbing rib structure according to a third embodiment of the present invention. [Figure 14] This is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in the third embodiment. [Figure 15] This is a schematic diagram showing a circular opening in the side wall. [Figure 16] This is a perspective view showing a pulp molded cushioning material provided with the shock-absorbing rib structure of the present invention. [Figure 17] This is a schematic diagram showing the test configuration in Verification Test 1. [Modes for carrying out the invention]

[0011] Before describing the embodiments, some preliminary information to facilitate understanding of the embodiments will be provided below.

[0012] As shown in Fig. 2, the impact buffering rib structure 110 of the conventional specification consists of a top plate 12 and a side wall 14, and has a hollow structure with an open bottom surface 16, that is, a structure of (a) a prism or (b) a cylinder. The mechanism of impact buffering by this impact buffering rib structure 110 is as follows.

[0013] Fig. 3 is a schematic cross-sectional view showing the compressive deformation of the side wall in the conventional specification. As shown in Fig. 3(a), Fig. 3(b) shows the impact buffering rib structure 110 viewed in the direction of arrow A.

[0014] When falling as a packaged cargo, with respect to the dynamic load DL received from the packaged object 20 acting thereon, the impact buffering rib structure 110 mainly supports the dynamic load DL with the side wall 14, and buffers the impact by the compressive or crushing stress due to the compressive deformation of the side wall 14. That is, by the side wall 14 of the impact buffering rib structure 110 being compressed and deformed, the impact acceleration applied to the packaged object 20 is reduced, and the packaged object 20 is protected.

[0015] For the design of such an impact buffering rib structure, the basic formula expressed by the following formula (1) is used. G (impact acceleration) = C (impact coefficient) × h (falling height) / t (thickness of the buffer material) ··· (1)

[0016] Specifically, aiming at the strain (ε) at which the impact coefficient (C) determined by the stress characteristics of the buffer material is minimized (see Fig. 4), and considering that the outer shape of the packaged object does not hit the bottom inside the packaged cargo. For example, as shown in Fig. 5, a clearance t c against the bottom contact of the packaged object is formed by the buffer material. Then, by adjusting the support area for supporting the load of the packaged object by the buffer material, the instantaneous strain amount of the impact buffering rib structure is designed to usually fall within the range of 0.4 to 0.6.

[0017] However, with the impact buffering rib structure 110 of the conventional specification shown in Fig. 2 and the above design method, the impact acceleration (G) has reached its reduction limit, and in order to further improve the impact buffering performance, a new impact buffering rib structure with a lower impact coefficient (C) is required.

[0018] In response, the inventors observed in detail the deformation state of the conventional shock-absorbing rib structure 110 and focused on the fact that compression and crushing were occurring predominantly on the top plate 12 side (see Figure 3). In other words, they found that the entire height of the rib structure was not being utilized, and the potential of the spring constant of the entire rib structure was being impaired.

[0019] Figure 6 is a schematic cross-sectional view showing a side wall with a slope. As shown in Figure 6(a), Figure 6(b) shows the impact-absorbing rib structure 110 viewed in the direction of arrow A. The side wall 14 of the impact-absorbing rib structure 110 has a slope (Δθ) due to its molding process. This is a feature that is pre-defined in the product shape to facilitate removal of the molded product from the mold.

[0020] Figure 7 is a cross-sectional view showing a side wall with a changing peripheral length (cross-sectional area). Sections B and C are views of the impact-absorbing rib structure 110 in the directions of arrows B and C, respectively. Because the impact-absorbing rib structure 110 has a slope (Δθ), the peripheral length (cross-sectional area) of the side wall 14 gradually increases toward its bottom surface 16 (opening bottom surface 16).

[0021] Therefore, the stress due to compression or crushing gradually decreases towards the lower part (bottom surface 16) of the rib structure 110. Consequently, it is thought that the compression or crushing is biased towards the top plate 12, which has a relatively weaker structure.

[0022] In the following embodiment, an impact-absorbing rib structure for pulp molded cushioning material that can reduce impact acceleration compared to conventional specifications will be described.

[0023] (First Embodiment) Figure 8 is a perspective view of a shock-absorbing rib structure according to the first embodiment of the present invention. As shown in Figure 8, the shock-absorbing rib structures 10 and 10' of this embodiment consist of a top plate 12 and side walls 14, and have a hollow structure with an open bottom surface 16, that is, a (a) rectangular prism or (b) cylindrical structure. The distance from the bottom surface 16 to the top plate 12 is defined as the height h of the shock-absorbing rib structure, and a plurality of openings 18 are provided in a range of half or less of the height h of the side wall 14.

[0024] The impact-absorbing rib structures 10 and 10' reduce the rigidity of the lower part of the rib structure by providing an opening 18 in the lower part of its side wall 14 (in a range of less than half the height h). In other words, by making the rigidity of the upper and lower parts of the rib structure roughly the same and ensuring consistency, the entire rib structure can be uniformly compressed and / or crushed.

[0025] Figure 9 is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in this embodiment. As shown in Figure 9(a), Figure 9(b) shows the impact-absorbing rib structure 10 viewed in the direction of arrow A.

[0026] The shock-absorbing rib structure 10 supports the dynamic load DL received from the packaged object 20 mainly with its side walls 14, but differs from conventional specifications (see Figure 3) in that the compression and crushing of the side walls 14 extends over the entire height range.

[0027] In this way, by utilizing the overall height of the rib structure as an impact absorption mechanism, the spring constant can be reduced compared to conventional specifications, thereby reducing the impact acceleration applied to the packaged object.

[0028] (Width of the opening) Figure 10 is a schematic diagram showing the dimensions of an opening in the side wall. As shown in Figure 10(a), the side wall 14 has a slope in the height direction. Let a be the distance perpendicular to the height direction from the midpoint of the height of the side wall 14 (h / 2) to the edge of the bottom surface 16 of the opening 18 on the outer surface of the side wall 14.

[0029] As shown in Figure 10(b), if the width W of the opening 18 is approximately 2a (W ≈ 2a), this is the most desirable configuration for making the rigidity of the upper and lower parts of the rib structure equal. The verification results for this will be discussed later.

[0030] (Second Embodiment) Figure 11 is a perspective view of a shock-absorbing rib structure according to a second embodiment of the present invention. In Figure 11, the same reference numerals are used for parts that are the same as those in Figure 8, and their detailed descriptions are omitted.

[0031] As shown in Figure 11, the impact-absorbing rib structure 10a of the pulp molded cushioning material differs from the impact-absorbing rib structure 10 according to the first embodiment in that multiple openings 18a are provided near the center of the height of the side wall 14.

[0032] This is intended to create a weakened section near the center of the height of the side wall 14, thereby causing a bend originating from the center.

[0033] Figure 12 is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in this embodiment. As shown in Figure 12(a), Figure 12(b) shows the impact-absorbing rib structure 10a viewed in the direction of arrow A.

[0034] The shock-absorbing rib structure 10 supports the dynamic load DL from the packaged object 20 mainly with its side walls 14, but differs from the previous embodiment in that bending and buckling occur in the side walls 14. By generating a bending stress smaller than the compressive stress across the entire area of ​​the side walls 14, the impact acceleration applied to the packaged object 20 can be reduced.

[0035] (Third embodiment) Figure 13 is a perspective view of a shock-absorbing rib structure according to a third embodiment of the present invention. In Figure 13, the same reference numerals are used for parts that are the same as those in Figure 8, and their detailed descriptions are omitted.

[0036] As shown in Figure 13, the impact-absorbing rib structure 10b of the pulp molded cushioning material differs from the impact-absorbing rib structures of the first and second embodiments in that multiple openings 18b are provided in an area of ​​more than half the height of the side wall 14.

[0037] This design aims to create a weakened section at the top of the side wall 14, causing the upper part of the rib structure to buckle prematurely due to low stress caused by bending stress, and then compression and / or collapse to occur below the center of the rib structure.

[0038] Figure 14 is a schematic cross-sectional view showing the deformation of the impact-absorbing rib structure in this embodiment. As shown in Figure 14(a), Figure 14(b) shows the impact-absorbing rib structure 10b viewed in the direction of arrow A.

[0039] The shock-absorbing rib structure 10 supports the dynamic load DL received from the packaged object 20 mainly with its side walls 14, but bending and buckling occur in the upper part of the side walls 14, and compression and crushing occur in the central part and below.

[0040] In this embodiment, the impact-absorbing rib structure 10b reduces the stress acting from the top of the rib structure in the initial stages of impact, thereby preventing a sudden impact from being applied to the packaged object and reducing the acceleration generated in the internal components of the packaged object.

[0041] Next, the advantageous configuration of the present invention will be described.

[0042] (Arrangement of openings) The openings 18, 18a, and 18b (hereinafter, only 18 will be described) may be provided in only one location on the side wall 14 of the impact-absorbing rib structure. Furthermore, if multiple openings 18 are provided, it is desirable to arrange them at equal intervals in the width direction of the side wall. This allows for uniform rigidity around the entire circumference of the impact-absorbing rib structure, resulting in an even greater effect.

[0043] (Shape of the opening) The shape of the opening is preferably polygonal (Figure 8) or circular (Figure 15). Impacts to the shock-absorbing rib structure are not always directed vertically, but can also come from unintended directions. By making the shape of the opening 18 polygonal or circular, it can respond to impacts from various directions.

[0044] (Shape of the shock-absorbing rib structure) The impact-absorbing rib structure is preferably a rectangular or cylindrical shape, as shown in Figure 8. Similar to the explanation regarding the shape of the opening, it can withstand impacts from various directions. Furthermore, using a rectangular prism for the impact-absorbing rib structure offers superior moldability, thus improving productivity.

[0045] Figure 16 is a perspective view showing a pulp molded cushioning material provided with the shock-absorbing rib structure of the present invention. This pulp molded cushioning material 30 is provided with at least one of the shock-absorbing rib structures 10 of the first to third embodiments. This pulp molded cushioning material 30 can accommodate a packaged object and reduce the impact acceleration acting on the packaged object compared to conventional pulp molded cushioning materials.

[0046] The top plate of the shock-absorbing rib structure 10 should preferably be in contact with the packaged object. By supporting the packaged object in the intended position, stable storage and retention can be achieved.

[0047] Furthermore, it is desirable that the open bottom surface 16 of the shock-absorbing rib structure 10 (see, for example, Figure 8) also contacts the packaged object. The product-holding surface 40 of the pulp molded cushioning material 30 contacts the flat surface of the packaged object, enabling stable storage and retention.

[0048] The pulp molded cushioning material 30 of this embodiment is attached to an image forming device (e.g., a copier, printer, etc.) as the object to be packaged, and then packed into packaging material (e.g., a corrugated cardboard box). This packaging material is used in a packaging system that includes packing machinery and equipment.

[0049] (Verification Test 1) This section describes a comparative verification test of the response acceleration of a packaged object using the conventional shock-absorbing rib structure and the present invention specification. Verification Method: Drop tests were conducted under the following conditions for both the conventional shock-absorbing rib structure and the shock-absorbing rib structure of the present invention, and the impact acceleration applied to the packaged object was measured.

[0050] Test specimen (see Figure 17): Main component m1 (aluminum material with a mass of 1.02 kg) Internal component m2 (aluminium material with a mass of 0.2 kg) Intermediate component k1 (gel sheet with a mass of 0.01 kg) Cushioning material k2 (recycled cardboard pulp molded cushioning material, thickness t=3mm) Here, the main component m1 is a model of the entire copier (an example of a precision machine), and the internal component m2 is a model of the parts built into that copier. The intermediate component k1 is a model of the part that supports the internal component m2 on the main component m1 and acts as a spring element. The support relationship between the internal component m2 and the intermediate member k1 was set to have a natural frequency of 200 Hz.

[0051] Types of cushioning material: Sample 1: Pulp molded cushioning material with a conventional shock-absorbing rib structure (Figure 2(a)). Sample 2 Pulp molded cushioning material having the impact-absorbing rib structure of the first embodiment (a rectangular prism with four openings at the bottom, Figure 8(a)) Sample 3 Pulp molded cushioning material having a shock-absorbing rib structure of the second embodiment (a rectangular prism with four openings in the center, Figure 11) Sample 4 Pulp molded cushioning material having a shock-absorbing rib structure of the third embodiment (a rectangular prism with four openings at the top, Figure 13)

[0052] Conditions and evaluation criteria: It is dropped from a height of 80 cm onto a flat floor surface. Samples 1 and 4 measure the impact acceleration acting on the main component m1 and the internal component m2, respectively. Samples 2 and 3 measure the impact acceleration applied to the main member m1.

[0053] Results: The results are shown in Table 1. Compared to sample 1 (conventional specifications), samples 2 and 3 (first and second embodiments) showed a reduction in the impact acceleration applied to the main member m1. Furthermore, compared to sample 1 (conventional specifications), sample 4 (third embodiment) showed a reduction in the impact acceleration applied to the internal component m2.

[0054] [Table 1]

[0055] (Verification test #2) Comparative verification test of impact absorption based on the width dimension of the opening. Verification Method: In a pulp molded cushioning material having the impact-absorbing rib structure of the first embodiment (a rectangular prism with four openings at the bottom, Figure 8(a)), the width of the openings was changed to two different types, and the impact acceleration acting on the packaged object was measured.

[0056] Sample: Main component m1 (aluminum material with a mass of 1.02 kg) Cushioning material k2 (recycled cardboard pulp molded cushioning material, thickness t=3mm)

[0057] Types of cushioning material: Sample 5 Pulp molded cushioning material having an impact-absorbing rib structure of the first embodiment (a rectangular prism with four openings at the bottom, Figure 8(a)) Here, the width W of the opening 18 shown in Figure 10 is denoted as a (W ≈ a). Sample 6 Pulp molded cushioning material having the impact-absorbing rib structure of the first embodiment (a rectangular prism with four openings at the bottom, Figure 8(a)) Here, the width W of the opening 18 shown in Figure 10 is set to 2a (W ≈ 2a).

[0058] Conditions and evaluation criteria: It is dropped from a height of 80 cm onto a flat floor surface. For both samples 5 and 6, the impact acceleration applied to the main member m1 is measured.

[0059] Results: The results are shown in Table 2. Compared to sample 5 (width of opening 18 W ≈ a), sample 6 (width of opening 18 W ≈ 2a) showed a reduction in impact acceleration.

[0060] [Table 2]

[0061] These verification tests show that, according to the configuration of each embodiment of the present invention, the impact acceleration applied to the packaged object (and internal components) can be reduced compared to the configuration of the conventional specification.

[0062] The present invention has been described in detail above using embodiments. These embodiments are examples and can be modified in various ways without departing from the spirit of the invention. For example, multiple embodiments and advantageous configurations may be combined. [Explanation of symbols]

[0063] 5, 105 Containment space 10, 10', 10a, 10b, 110 Shock-absorbing rib structure 12 Top plate 14 Side wall 16 (Opening) Bottom 18, 18a, 18b: opening 20 Packaged object 30, 100: Pulp molded cushioning material 40 Product storage surfaces [Prior art documents] [Patent Documents]

[0064] [Patent Document 1] Japanese Patent Publication No. 2006-89074

Claims

1. A rib structure for shock absorption in pulp molded cushioning material, In a hollow shock-absorbing rib structure consisting of a top plate and side walls, with an open bottom, The distance from the bottom surface to the top plate is defined as the height of the shock-absorbing rib structure. At least one opening is provided in the area of ​​the side wall that is less than half the height of the side wall. The side wall has a slope in the height direction and is closed around the entire circumference of the top plate. An impact-absorbing rib structure characterized in that the rigidity of the upper part and the rigidity of the lower part in the height direction of the impact-absorbing rib structure are of a similar degree.

2. The impact-absorbing rib structure according to claim 1, characterized in that a plurality of openings are arranged at equal intervals in the width direction of the side wall.

3. The impact-absorbing rib structure according to claim 1 or 2, characterized in that the shape of the opening is polygonal or circular.

4. The impact-absorbing rib structure according to any one of claims 1 to 3, characterized in that the impact-absorbing rib structure is a rectangular prism or a cylindrical shape.

5. The impact-absorbing rib structure according to any one of claims 1 to 4, characterized in that the impact-absorbing rib structure is a rectangular prism.

6. It has a space for accommodating the packaged object, A pulp molded cushioning material having at least one of the impact-absorbing rib structures described in any one of claims 1 to 5.

7. The pulp mold cushioning material according to claim 6, characterized in that the top plate of the impact-absorbing rib structure is in contact with the packaged object.

8. The pulp mold cushioning material according to claim 6, characterized in that the open bottom surface of the shock-absorbing rib structure comes into contact with the packaged object.

9. A packaging material for packaging an object to be packaged, which is fitted with the pulp mold cushioning material described in any one of claims 6 to 8.

10. A packaging system using the packaging material described in claim 9.

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