Cushioning material, packing material and pack

Abstract

To provide a cushioning material, packing material and pack that has high versatility and can be made smaller in thickness.SOLUTION: A cushioning material 40 is to buffer an external force applied to an electronic appliance. The cushioning material 40 comprises a support board 42 and a cushioning part 50. The support board 42 is a member for supporting an electronic appliance. The cushioning part 50 is provided on the support board 42 and for buffering an external force applied to the electronic appliance. The cushioning part 50 comprises a first cushioning portion 51 and a second cushioning portion 52. The first cushioning portion 51 has a first face 61 to be fixed to the support board 42 and a second face 62 to face the electronic appliance. The second cushioning portion 52 has a third face 63 to be fixed to the support board 42 and a fourth face 64 to face the electronic appliance. In a graph taking an ordinate axis as an external force applied to the electronic appliance and an abscissa axis as time from a start of application of an external force to the electronic appliance, graph waveform types are different between the first cushioning portion 51 and the second cushioning portion 52.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cushioning material, a packaging material, and a packaged product. [Background technology]

[0002] For example, Patent Document 1 discloses a cushioning material made of a stack of multiple buffer sheets that buffer external forces applied to an electronic device, as well as packaging materials and packages using this cushioning material. The multiple buffer sheets include a first buffer sheet arranged so as to intersect with the direction of the external force applied to the electronic device, and a second buffer sheet that has a strength higher than that of the first buffer sheet in the direction of the external force applied to the electronic device and is arranged so as to intersect with the direction of the external force applied to the electronic device. The cushioning material is made of cardboard. The first buffer sheet and the second buffer sheet each constitute different layers of the multiple layers that make up the cardboard. The cushioning effect of the cushioning material is enhanced by using cardboard made of two types of buffer sheets with different strengths. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-120487 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the required cushioning characteristics vary depending on the type of electronic device. Conventional cushioning materials are configured by stacking a first cushioning sheet and a second cushioning sheet in series in a direction facing the electronic device. Therefore, when responding to the differences in required cushioning characteristics, various conditions such as the thickness, number of layers, and material of the cushioning sheet must be selected and built-in, resulting in poor versatility. Therefore, there is a demand for a cushioning material that has high cushioning effect and is highly versatile. [Means for solving the problem]

[0005] The buffer material that solves the above problem is a buffer material that buffers external forces applied to an electronic device, the buffer material comprising a support plate for supporting the electronic device and a buffer section provided on the support plate that buffers the external forces applied to the electronic device, the buffer section comprising a first buffer section having a first surface fixed to the support plate and a second surface facing the electronic device, and a second buffer section having a third surface fixed to the support plate and a fourth surface facing the electronic device, and in a graph where the vertical axis represents the external force applied to the electronic device and the horizontal axis represents the time from when the external force begins to be applied to the electronic device, the types of waveforms of the graph for the first buffer section and the second buffer section are different.

[0006] A cushioning material that solves the above-mentioned problems is a cushioning material that cushions an external force applied to an electronic device, the cushioning material comprising: a support plate for supporting the electronic device; and a cushioning section provided on the support plate that cushions the external force applied to the electronic device, the cushioning section comprising: a first cushioning section having a first surface fixed to the support plate and a second surface facing the electronic device; and a second cushioning section having a third surface fixed to the support plate and a fourth surface facing the electronic device, wherein in a stress-strain diagram with the vertical axis representing the compressive stress applied to the cushioning section and the horizontal axis representing the strain applied to the cushioning section, (a) the maximum stress in the elastic region of the first cushioning section is , is greater than the maximum stress in the elastic region of the second buffer section, (b) the slope indicating the ratio of stress to strain in the plastic region of the first buffer section is zero or close to zero, and the slope indicating the ratio of stress to strain in the plastic region of the second buffer section is a greater positive value than the slope of the first buffer section, and (c) the maximum stress in the elastic region of a composite buffer section formed by arranging the first buffer section and the second buffer section in parallel in a direction facing the electronic device is greater than the maximum stress of the second buffer section, and the slope in the plastic region of the composite buffer section is a greater positive value than the slope of the first buffer section.

[0007] The packaging material that solves the above problem includes a packaging box that can accommodate the electronic device, and the above cushioning material. A package that solves the above problem includes the above packaging material and the electronic device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an exploded perspective view showing an example of the configuration of a packaging material according to the first embodiment. [Figure 2] FIG. 2 is a perspective view showing an example of the structure of the buffer material. [Figure 3] FIG. 3 is a perspective view showing the buffer section. [Figure 4] FIG. 4 is a side cross-sectional view of the buffer section taken along a plane perpendicular to the fixed surface. [Figure 5] FIG. 5 is a graph showing a stress-strain diagram when corrugated cardboard material is compressed. [Figure 6] FIG. 6 is a graph showing a stress-strain diagram when a foamed resin material is compressed. [Figure 7] FIG. 7 is a graph showing a stress-strain diagram when the composite buffer section is compressed. [Figure 8] FIG. 8 is a graph showing the relationship between acceleration applied to an electronic device via a cardboard material and time. [Figure 9] FIG. 9 is a graph showing the relationship between acceleration applied to an electronic device via a foamed resin material and time. [Figure 10] FIG. 10 is a graph showing the relationship between acceleration applied to an electronic device via a composite buffer section and time. [Figure 11] FIG. 11 is a perspective view showing the cushioning material of the second embodiment. [Figure 12] FIG. 12 is a side cross-sectional view showing a cross section of the cushioning material. [Figure 13] FIG. 13 is a perspective view showing a cushioning material of the third embodiment. [Figure 14] FIG. 14 is a side cross-sectional view showing a cross section of the cushioning material. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the packaging product and the cushioning material will be described with reference to Figures 1 to 10. First, with reference to Figure 1, an overall outline of the packaging product and the packaging material will be described. <Overview of packaging items and packaging materials> 1 is an exploded perspective view showing an example of the configuration of a package 10 and a package material 20. The package 10 includes the package material 20 and an electronic device 100. The package 10 is formed by packaging the electronic device 100 in the package material 20.

[0010] The packaging material 20 has a cushioning material 40 that cushions external forces applied to the electronic device 100. The packaging material 20 may include a packaging box 30 that can house the electronic device 100, and the cushioning material 40. The packaging box 30 has a bottomed box-shaped main body 31 that has an opening 33 that opens upward, and four flaps 32 that extend from the four sides of the main body 31 that surround the opening 33.

[0011] As shown in FIG. 1, the cushioning material 40 is interposed between the packaging box 30 and the electronic device 100. That is, the electronic device 100 is housed in the packaging box 30 via the cushioning material 40. The packaging material 20 may include a plurality of cushioning materials 40. The electronic device 100 is housed in the packaging box 30 while being protected by the plurality of cushioning materials 40. The plurality of cushioning materials 40 are arranged so as to surround the electronic device 100. In the example shown in FIG. 1, the electronic device 100 has, for example, a rectangular parallelepiped shape. The rectangular parallelepiped electronic device 100 has four corners on four sides that are parallel to each other. In the example shown in FIG. 1, four cushioning materials 40 are arranged at the four corners of the electronic device 100.

[0012] The cushioning material 40 includes a cushioning section 50 that cushions external forces (impact forces) applied to the electronic device 100 housed in the packaging box 30. The packaged item 10 is subjected to external forces (impact forces) such as an impact when a worker accidentally drops the packaged item 10 during sorting, loading, or transportation, or an impact due to shaking or vibration during transportation. The cushioning material 40 protects the electronic device 100 from these types of external forces.

[0013] Here, the electronic device 100 is, for example, a recording device 110. The recording device 110 is an inkjet printer or the like. However, the recording device 110 is not limited to an inkjet printer, and may be, for example, a laser printer, a dot matrix printer, or the like. The recording device 110 may also be a printer dedicated to recording, or a multifunction device that combines a recording function with other functions. Examples of other functions of a multifunction device include a scanner function, a copy function, and a facsimile function. In this embodiment, the electronic device 100 may be a device other than the recording device 110, such as a scanner, a television, a refrigerator, a washing machine, a microwave oven, or a personal computer.

[0014] In the example shown in FIG. 1, it is assumed that the packaging material 20 has four cushioning materials 40A to 40D. The electronic device 100 and the four cushioning materials 40A to 40D are placed into the packaging box 30 through the opening 33. That is, the electronic device 100 is placed in the packaging box 30 with its four corners (top, bottom, left, and right) protected by the four cushioning materials 40 shown in FIG. 1 . The opening 33 of the packaging box 30 is then closed by four flaps 32. The four flaps 32 are held closed by adhesive tape or adhesive. In this way, the packaged item 10 is completed. Within the packaged item 10, the electronic device 100 is protected by the four cushioning materials 40A to 40D interposed between the electronic device 100 and the packaging box 30. The electronic device 100 faces the cushioning sections 50 of the four cushioning materials 40A to 40D.

[0015] For ease of explanation, a packaging box coordinate system fixed to the packaging box 30 will be introduced below. The packaging box coordinate system is a three-axis coordinate system having an XW axis, a YW axis, and a ZW axis, which are perpendicular to each other. The ZW axis extends in the ZW direction, which is the direction from the opening 33 of the packaging box 30 toward the bottom surface. The XW axis extends in the XW direction perpendicular to the ZW direction. The YW axis extends in the YW direction perpendicular to the ZW and XW directions. Note that the XW axis, YW axis, and ZW axis do not necessarily have to be perpendicular to each other, as long as they intersect with each other. Furthermore, hereinafter, the direction opposite to the XW direction will be referred to as the -XW direction, the direction opposite to the YW direction will be referred to as the -YW direction, and the direction opposite to the ZW direction will be referred to as the -ZW direction.

[0016] In the example shown in FIG. 1, the electronic device 100 is protected at four locations by four cushioning materials 40A to 40D. The cushioning material 40A protects the lower left end of the electronic device 100 in the ZW direction and the -XW direction. The cushioning material 40B protects the lower right end of the electronic device 100 in the ZW direction and the +XW direction. The cushioning material 40C protects the upper left end of the electronic device 100 in the -ZW direction and the -XW direction. The cushioning material 40D protects the upper right end of the electronic device 100 in the -ZW direction and the +XW direction.

[0017] Cushioning material 40A has a plurality of buffer sections 50 that face electronic device 100 in the -ZW, XW, YW, and -YW directions. Cushioning material 40B has a plurality of buffer sections 50 that face electronic device 100 in the -ZW, -XW, YW, and -YW directions. Cushioning material 40C has a plurality of buffer sections 50 that face electronic device 100 in the ZW, XW, YW, and -YW directions. Cushioning material 40D has a plurality of buffer sections 50 that face electronic device 100 in the ZW, -XW, YW, and -YW directions. In this manner, all of the multiple surfaces (six surfaces) that form the outer periphery of electronic device 100 face at least one buffer section 50. In this embodiment, all of the multiple surfaces (six surfaces) that form the outer periphery of electronic device 100 face multiple buffer sections 50.

[0018] <Configuration of the buffer material 40 and the buffer section 50> An example of the configuration of the buffer material 40 and the buffer section 50 will be described below with reference to Figures 2 to 4. The four buffer materials 40A to 40D shown in Figure 1 basically have the same configuration. In the following description, when there is no need to particularly distinguish between the four buffer materials 40A to 40D, they will simply be referred to as buffer material 40.

[0019] 2, the cushioning material 40 includes a support section 41 for supporting the electronic device 100 and a buffer section 50 for buffering an external force applied to the electronic device 100. The buffer section 50 is provided in the support section 41. The cushioning material 40 shown in FIG. 2 is an example in which a plurality of buffer sections 50 are provided in the support section 41.

[0020] The support unit 41 includes four support plates 42A to 42D. The four support plates 42A to 42D have surfaces to which the buffer unit 50 is fixed facing in different directions. The support unit 41 has a predetermined shape as shown in FIG. 2, in which the four support plates 42A to 42D can face four surfaces of a portion of the electronic device 100 that includes two corners on both sides of one side. The support unit 41 may be formed into the predetermined shape shown in FIG. 2 using a plurality of plate materials, or may be formed into the predetermined shape shown in FIG. 2 by bending a single plate material. The support unit 41 may be formed, for example, from cardboard. The cardboard may be made of paper or synthetic resin.

[0021] Specifically, support unit 41 includes two support plates 42A and 42D that are perpendicular to each other, and two support plates 42B and 42C that face each other and have faces perpendicular to the two support plates 42A and 42D. Support unit 41 has a predetermined shape that allows four support plates 42A to 42D to face four faces of a portion including two corners on both sides of one side of rectangular parallelepiped electronic device 100.

[0022] 2 are referred to as a first support plate 42A, a second support plate 42B, a third support plate 42C, and a fourth support plate 42D. The first support plate 42A forms the bottom surface of the cushioning material 40. The second support plate 42B forms one of two side surfaces of the cushioning material 40. The third support plate 42C forms the other of two side surfaces of the cushioning material 40. The fourth support plate 42D forms the back surface of the cushioning material 40. In this embodiment, it is assumed, as an example, that each of the multiple support plates 42A to 42D that form the support portion 41 is made of cardboard.

[0023] In the example shown in Fig. 2, two buffer sections 50 are fixed to the first support plate 42A. One buffer section 50 is fixed to the second support plate 42B. One buffer section 50 is fixed to the third support plate 42C. Two buffer sections 50 are fixed to the fourth support plate 42D. Note that this embodiment is characterized by the configuration of the buffer sections 50 that the buffer material 40 has.

[0024] For ease of explanation, a buffer coordinate system will be introduced below for each buffer section 50 according to the direction facing electronic device 100. Furthermore, when there is no need to particularly distinguish between the four support plates 42A to 42D of buffer 40, they will simply be referred to as support plates 42.

[0025] 2, the X1 axis, Y1 axis, and Z1 axis of the cushioning material coordinate system are shown, focusing on the first support plate 42A, which is one of the plate-shaped portions of the four support plates 42A to 42D. The cushioning material coordinate system is a three-axis coordinate system having the X1 axis, Y1 axis, and Z1 axis, which are perpendicular to each other. The X axis extends in the X1 direction. The Y axis extends in the Y1 direction. The Z axis extends in the Z1 direction. The X1 direction, Y1 direction, and Z1 direction of the cushioning material coordinate system are a three-axis coordinate system defined for each support plate 42 based on the following definitions.

[0026] Here, the Z1 direction is the direction from one of the multiple surfaces of the buffer unit 50 that contacts the support plate 42 to another surface located on the opposite side of the one surface. The Z1 direction is a direction perpendicular to the extension direction of the support plate 42. The X1 direction is a direction perpendicular to the Z1 direction and parallel to the extension direction of the support plate 42. The Y1 direction is a direction perpendicular to the Z1 direction and the X1 direction and parallel to the extension direction of the support plate 42. Note that the X-axis, Y-axis, and Z-axis may intersect with each other. Hereinafter, the direction opposite the X1 direction will be referred to as the X2 direction, the direction opposite the Y1 direction will be referred to as the Y2 direction, and the direction opposite the Z1 direction will be referred to as the Z2 direction. The buffer coordinate system is set so that the direction of the buffer unit 50 as seen from the electronic device 100 (see FIG. 1) is the Z1 direction. Note that a buffer coordinate system is set for each buffer unit 50.

[0027] <Configuration of the cushioning material 40> Next, the configuration of the cushioning material 40 will be described with reference to Figures 3 and 4. Below, one of the multiple cushioning sections 50 included in the cushioning material 40 will be described. Figure 3 shows a perspective view of the cushioning section 50. Figure 4 shows a cross section of the cushioning section 50 taken along a plane perpendicular to the fixed surface 42P of the support plate 42.

[0028] 3 and 4, one buffer section 50 is fixed to a fixed surface 42P of the support plate 42 that is perpendicular to the Z1 direction. The buffer section 50 includes a first buffer section 51 and a second buffer section 52. The first buffer section 51 and the second buffer section 52 are fixed in a state in which they are arranged in parallel with the fixed surface 42P of the support plate 42.

[0029] The first buffer section 51 has a first surface 61 fixed to the support plate 42 and a second surface 62 facing the electronic device 100. The second buffer section 52 has a third surface 63 fixed to the support plate 42 and a fourth surface 64 facing the electronic device 100. In other words, the surface where the first buffer section 51 is fixed to the support plate 42 is the first surface 61. The surface where the second buffer section 52 is fixed to the support plate 42 is the third surface 63. Furthermore, the surface where the first buffer section 51 faces the electronic device 100 is the second surface 62. The surface where the second buffer section 52 faces the electronic device 100 is the fourth surface 64.

[0030] The second surface 62 and the fourth surface 64 may be flush. By being flush, the first buffer section 51 and the second buffer section 52 can have the second surface 62 and the fourth surface 64 come into contact with the surface facing the electronic device 100 at approximately the same time when the packaged item 10 is dropped. For example, the thickness of the first buffer section 51 and the thickness of the second buffer section 52 may be made the same, so that the second surface 62 and the fourth surface 64 are disposed flush.

[0031] As shown in FIGS. 3 and 4, the first buffer section 51 and the second buffer section 52 may be disposed in contact with each other. Furthermore, as shown in FIGS. 3 and 4, one of the first buffer section 51 and the second buffer section 52 may be disposed surrounded by the other. In the buffer section 50, one of the first buffer section 51 and the second buffer section 52 may have a plate shape of a predetermined shape, and the other may have an annular plate shape surrounding the first buffer section. In the example shown in FIGS. 3 and 4, the first buffer section 51, which is one example, is disposed surrounded by the second buffer section 52, which is the other example. In the example shown in FIGS. 3 and 4, the predetermined shape is rectangular. The first buffer section 51, which is one example, has a square plate shape. The second buffer section 52, which is the other example, has a square annular plate shape surrounding the first buffer section 51. The predetermined shape may be a circle, a triangle, a pentagon, a hexagon, or the like. In the buffer section 50 of this embodiment, the first buffer section 51 and the second buffer section 52 are arranged in parallel in a state of contact with each other, thereby constituting a composite buffer section 53 in the form of a single assembly.

[0032] In this embodiment, the first buffer section 51 is made of corrugated cardboard material. The second buffer section 52 is made of foamed resin material. The corrugated cardboard material may be made of paper or synthetic resin. The first buffer section 51 may be made of the same type of corrugated cardboard material as the support section 41 (support plate 42), or may be made of a different type of corrugated cardboard material from the support section 41. Here, the type of corrugated cardboard material refers to the type that determines the strength. The strength of the corrugated cardboard material is determined, for example, by the structure, number of layers, and thickness of the corrugated cardboard sheets that make up the corrugated cardboard material. In this regard, the type of corrugated cardboard material may be the type of structure of the corrugated cardboard sheet, the number of layers of the corrugated cardboard sheet, or the type of thickness of the corrugated cardboard sheet (thickness per layer).

[0033] As shown in FIG. 4, the corrugated cardboard material constituting the first buffer section 51 has a multi-layer structure in which multiple corrugated cardboard sheets 51A are stacked. The corrugated cardboard sheet 51A has a structure in which two liners made of flat paper and a corrugated cardboard core are bonded with adhesive. The multiple corrugated cardboard sheets 51A constituting the first buffer section 51 have the same layer structure. The multiple corrugated cardboard sheets 51A also have the same thickness. The corrugated cardboard material constituting the first buffer section 51 has a layer structure of two or more layers. The example shown in FIG. 4 has four layers, but it may have three, five, six, or seven or more layers. The number of layers of the corrugated cardboard sheet 51A is set depending on the required buffer characteristics.

[0034] The foamed resin material constituting the second buffer section 52 is a foamed resin material made of a synthetic resin material. The synthetic resin material is, for example, polyethylene (PE). The synthetic resin material may be polybutene (PB), polystyrene (PS), polyurethane (PU), or the like. The foamed resin material may have an expansion ratio of, for example, within a range of 10 to 80 times. The thickness of the foamed resin material that is the material for the second buffer section 52 may be set to the same thickness as the thickness of the cardboard material, which is determined by the number of layers of the cardboard sheet 51A.

[0035] The reason for using first buffer section 51 and second buffer section 52 made of different types of material is to obtain buffer characteristics suitable for protecting electronic device 100 by configuring composite buffer section 53 by combining members made of two types of materials with different buffer characteristics. In this case, the buffer characteristics of composite buffer section 53 can be adjusted by adjusting the area ratio between first buffer section 51 and second buffer section 52. In other words, the buffer characteristics of composite buffer section 53 can be adjusted by adjusting the area ratio, which is the ratio between the area of ​​second surface 62 of first buffer section 51 and the area of ​​fourth surface 64 of second buffer section 52.

[0036] In the example shown in FIGS. 3 and 4 , in which the second surface 62 and the fourth surface 64 are flush with each other, the thickness of the first buffer section 51 and the thickness of the second buffer section 52 are the same. The cushioning characteristics of the buffer section 50 can be adjusted by adjusting the area ratio between the second surface 62 and the fourth surface 64 while maintaining the condition that the second surface 62 and the fourth surface 64 are flush with each other. In this embodiment, the area ratio between the second surface 62 of the first buffer section 51 and the fourth surface 64 of the second buffer section 52 is set to a value that provides the cushioning characteristics necessary to protect the electronic device 100. For example, the area ratio may be determined based on the results of a drop impact test.

[0037] <Stress-strain diagram> Next, stress-strain curves of the buffer section 50 will be described with reference to FIGS. 5 to 7. FIGS. 5 to 7 are stress-strain curves when an external force (compressive force) is applied to each of the buffer sections 51, 52, and 53 in the compression direction. The stress σ on the vertical axis represents compressive stress. The strain ε is on the horizontal axis. FIG. 5 is a stress-strain curve for the first buffer section 51. This is the stress-strain curve for the corrugated cardboard material that is the material for the first buffer section 51. FIG. 6 is a stress-strain curve for the second buffer section 52. This is the stress-strain curve for the foamed resin material that is the material for the second buffer section 52. FIG. 7 is a stress-strain curve for the buffer section 50. This is the stress-strain curve for the composite buffer section 53, which is formed by arranging corrugated cardboard and foamed resin in parallel with each other in the compression direction. Each stress-strain curve has a usable region UA ​​and an unusable region NA. The usable region UA ​​is the region that can be used as a buffer material. The unusable area NA is an area that cannot be used as a buffer material. The unusable area NA is not taken into account when evaluating the characteristics of the buffer material.

[0038] As shown in Figure 5, corrugated cardboard elastically deforms up to a maximum stress σ1. That is, it elastically deforms in the elastic region EA from the compression start point (σ = 0) until it reaches the maximum stress σ1. In the elastic region EA, the rate of change of stress σ with respect to strain ε is constant. In the elastic region EA, the curve forms an approximately straight line with a constant slope. In the plastic region PA after reaching the maximum stress σ1, the rate of change of stress σ with respect to strain ε is smaller than the rate of change in the elastic region EA. As shown in Figure 5, in the case of corrugated cardboard, stress σ maintains a constant value σ1 in the plastic region PA. This means that in the elastic region EA, the multiple layers of cardboard sheets 51A that make up the cardboard all have the same strength, so they collapse almost simultaneously when the maximum stress is reached. The cardboard sheets 51A absorb the impact force as they collapse. Therefore, in the plastic region PA, there is almost no cushioning capacity (shock absorption capacity). As can be seen from the graph shown in FIG. 5, the corrugated cardboard material that is the material of the first buffer section 51 has a large maximum stress σ1 and therefore high creep characteristics, but its buffering capacity in the plastic region PA is extremely low.

[0039] As shown in FIG. 6, the foamed resin material elastically deforms up to the maximum stress σ2. That is, in the elastic region EA until the maximum stress σ2 is reached, the rate of change of stress σ with respect to strain ε is constant. After the maximum stress σ2 is reached, in the plastic region PA, the rate of change of stress σ with respect to strain ε becomes a positive value. That is, unlike corrugated cardboard, the foamed resin material has a buffering capacity (shock absorption capacity) due to plastic deformation (viscoelastic deformation) in the plastic region PA. Although the foamed resin material used for the second buffer section 52 has a small maximum stress σ2, it still has buffering capacity even in the plastic region PA. Because the foamed resin material has a small maximum stress σ2, it has low creep characteristics. Therefore, when using a foamed resin material alone, the surface area of ​​the buffer section 50 facing the electronic device 100 must be large. In this case, a large surface area is also required on the surface facing the electronic device 100, which may not be possible depending on the shape and size of the electronic device 100.

[0040] As shown in FIG. 7, the composite buffer 53 elastically deforms up to a maximum stress σ3. That is, in the elastic region EA, the rate of change of stress σ with respect to strain ε is a relatively large constant value. This maximum stress σ3 is larger than the maximum stress σ2 of the foamed resin material shown in FIG. 6. By arranging the first buffer 51 and the second buffer 52 in parallel, a large maximum stress σ3 is obtained. This large maximum stress σ3 is caused by the corrugated cardboard material. On the other hand, in the plastic region PA after reaching the maximum stress σ3, the rate of change of stress σ with respect to strain ε is a positive value. By arranging the first buffer 51 and the second buffer 52 in parallel, the composite buffer 53 undergoes plastic deformation in the plastic region PA. This plastic deformation is viscoelastic deformation. This plastic deformation is caused by the foamed resin material. As such, the composite buffer 53 has high creep characteristics due to the large maximum stress σ3 and also undergoes plastic deformation in the plastic region PA, resulting in high buffering capacity (shock absorption capacity).

[0041] As can be seen from FIGS. 5 to 7, the composite buffer section 53, in which the first buffer section 51 and the second buffer section 52 are arranged in parallel, has a larger maximum stress σ3 than the case of foamed resin material alone. Moreover, the rate of change (slope) of stress σ with respect to strain ε is positive in the plastic region PA. As can be seen from the stress-strain diagrams shown in FIGS. 5 to 7, the first buffer section 51, the second buffer section 52, and the composite buffer section 53 have the following relationships (a) to (c). In this embodiment, a composite buffer section 53 that satisfies these relationships is used. (a) The maximum stress σ1 in the elastic region EA of the first buffering section 51 is greater than the maximum stress σ2 in the elastic region EA of the second buffering section 52. (b) The slope indicating the ratio of stress to strain ε in the plastic region PA of the first buffer section 51 is zero or close to zero, and the slope indicating the ratio of stress to strain ε in the plastic region PA of the second buffer section 52 is a positive value greater than the slope of the first buffer section 51. (c) The maximum stress σ3 in the elastic region EA of the composite buffer section 53, which is formed by arranging the first buffer section 51 and the second buffer section 52 in parallel in a direction facing the electronic device 100, is greater than the maximum stress σ2 of the second buffer section 52, and the slope of the composite buffer section 53 in the plastic region PA is a larger positive value than the slope of the first buffer section 51.

[0042] By satisfying the relationships shown in (a) to (c) above, it is possible to obtain a buffer section 50 having excellent buffering properties. <Relationship between acceleration and time when impact is applied> Next, with reference to FIGS. 8 to 10, the relationship between time and the acceleration of an external force applied to electronic device 100 via the buffer unit when an impact is applied will be described. In the graphs shown in FIGS. 8 to 10, the vertical axis represents the acceleration G of the external force applied to electronic device 100, and the horizontal axis represents time t. Time t is the elapsed time since the external force began to be applied to electronic device 100. The graphs show the relationship between time t and the acceleration G of the external force applied to electronic device 100 when electronic device 100 is dropped from a predetermined height with buffer units interposed between electronic device 100 and the floor. When electronic device 100 is dropped onto the floor, it receives a compressive force as an external force from the buffer unit. Therefore, acceleration corresponding to the compressive force occurs in electronic device 100. The buffer units are first buffer unit 51, second buffer unit 52, and composite buffer unit 53.

[0043] FIG. 8 shows the relationship between the acceleration G of the external force applied to the electronic device 100 when dropped and time t when the buffer is made of the cardboard material constituting the first buffer 51. FIG. 9 shows the relationship between the acceleration G of the external force applied to the electronic device 100 when dropped and time t when the buffer is made of the foam resin material constituting the second buffer 52. FIG. 10 shows the relationship between the acceleration G of the external force applied to the electronic device 100 when dropped and time t when the buffer is made of the composite buffer 53. Each graph also shows the relationship between the external force applied to the electronic device 100 when an impact is applied and time. The external force applied to the electronic device 100 when an impact is applied depends on the mass of the electronic device 100. If the mass of the electronic device 100 is the same, the waveform of each graph also shows the relationship between the external force applied to the electronic device 100 and time. Note that FIG. 8 assumes the following state when the electronic device 100 is dropped from a predetermined height with the first buffer 51 interposed between the electronic device 100 and the floor. That is, it is assumed that electronic device 100 stops before all of the plurality of cardboard sheets 51A that make up first buffer section 51 are compressed and crushed.

[0044] As shown in FIGS. 8 and 9, the waveforms of the graphs of the first buffering section 51 and the second buffering section 52 are different. The waveform of the graph of the first buffering section 51 is a trapezoidal wave. The waveform of the graph of the second buffering section 52 is a half-sine wave. That is, the first buffering section 51 includes a material that forms a trapezoidal wave. The second buffering section 52 includes a material that forms a half-sine wave. In this embodiment, the first buffering section 51 includes a corrugated cardboard material as a material that forms a trapezoidal half-wave. The second buffering section 52 includes a foamed resin material as a material that forms a half-sine wave. The waveform of the corrugated cardboard material is a trapezoidal wave because, in the stress-strain curve shown in FIG. 5, the rate of change of stress σ with respect to strain ε is approximately 0 (zero) in the plastic region PA. The waveform of the foamed resin material is a half-sine wave because, in the stress-strain curve shown in FIG. 6, the rate of change of stress σ with respect to strain ε is a positive value in the plastic region PA.

[0045] The trapezoidal wave, which is the waveform of the graph of cardboard material, is a composite wave formed by superimposing multiple half-sine waves with different frequencies. If this trapezoidal wave contains a frequency that is the same as the natural frequency of the electronic device 100, the electronic device 100 will resonate. In this case, a large impact will be applied to the electronic device 100. The natural frequency of the electronic device 100 will differ depending on the type of electronic device 100 being packaged. Therefore, in order to provide a versatile cushioning material 40, it is necessary to prevent any type of electronic device 100 from resonating.

[0046] 10 includes a half-sine wave and does not include a trapezoidal wave. Therefore, electronic device 100 is less likely to resonate when dropped onto the floor via buffer unit 50 (composite buffer unit 53).

[0047] Furthermore, cardboard made of paper is vulnerable to humidity. When paper absorbs moisture, its strength decreases. In other words, in the stress-strain diagram shown in Figure 5, the maximum stress σ1 of cardboard that has absorbed moisture decreases. In order to ensure the necessary cushioning force even when the strength of the cardboard decreases due to humidity, the thickness of the cardboard must be made thicker than the value required when it is dry. This increases the thickness of the buffer section 50 and ultimately leads to an increase in the size of the packaged item 10.

[0048] In contrast, the buffer section 50 of this embodiment is partially made of a water-resistant foamed resin material. Therefore, the first buffer section 51 made of corrugated cardboard can be made thinner depending on the proportion of foamed resin material in the composite buffer section 53. Therefore, even if a thickness that takes into account the influence of humidity is added to the thickness of the thinned corrugated cardboard, it is still possible to make the thickness of the first buffer section 51 that constitutes the composite buffer section 53 thinner than when the buffer section 50 is made of corrugated cardboard alone. Therefore, the buffer section 50 made of the composite buffer section 53 can be made thinner.

[0049] <Operation of the embodiment> Next, the functions of the packaged product 10, the packaging material 20, and the cushioning material 40 will be described. In this embodiment, the cushioning section 50 is formed by arranging a first cushioning section 51 and a second cushioning section 52, each made of a different cushioning material, in parallel with the compression direction. This makes it possible to control the cushioning characteristics by adjusting the area ratio between the first cushioning section 51 and the second cushioning section 52. The cushioning section 50 is formed by a composite cushioning section 53, which is formed by arranging the first cushioning section 51 and the second cushioning section 52 in parallel with the compression direction. The maximum stress σ3 of the composite cushioning section 53 increases by increasing the area ratio of the first cushioning section 51 made of corrugated cardboard. Furthermore, the positive slope, which indicates the rate of change of stress σ with strain ε in the plastic region PA of the composite cushioning section 53, increases by increasing the area ratio of the second cushioning section 52 made of a foamed resin material.

[0050] As shown in FIG. 7, the buffer 50 made of the composite buffer 53 has a maximum stress σ3 that is sufficiently greater than the maximum stress σ2 of the foamed resin material alone. That is, the buffer 50 has a high maximum stress σ3 that is closer to the maximum stress σ1 of the cardboard material than the maximum stress σ2 of the foamed resin material. This improves the creep characteristics of the buffer 50. For example, when constructed using only foamed resin material, the maximum stress σ2 is small, resulting in poor creep characteristics. In this case, the area of ​​the foamed resin material needs to be increased. In contrast, the buffer 50 can achieve a higher maximum stress σ3 than the foamed resin material alone. This contributes to the miniaturization (reduced area) of the buffer 50.

[0051] As shown in Fig. 7, the slope of the buffer 50 made of the composite buffer 53, which indicates the rate of change of the stress σ with respect to the strain ε, is a positive value. Therefore, the waveform of the acceleration of the external force applied to the electronic device 100 when it is dropped (impact waveform) becomes a half-sine wave as shown in Fig. 10. In other words, the impact waveform does not include a trapezoidal wave (Fig. 8). Therefore, when the package 10 is dropped, the electronic device 100 that comes into contact with the buffer 50 made of the composite buffer 53 is less likely to resonate.

[0052] Furthermore, if the buffer section 50 is made of cardboard material alone, its buffering properties are likely to deteriorate due to the influence of humidity. Therefore, it is necessary to increase the thickness of the buffer section 50 in consideration of the influence of humidity. In other words, it is necessary to make the cardboard material thicker so that the necessary buffering properties can be obtained even if the buffering properties deteriorate due to the influence of humidity. This leads to an increase in the size of the package 10.

[0053] In contrast, the buffer section 50 of this embodiment is made of a composite buffer section 53, which is an assembly of corrugated cardboard and foamed resin. Therefore, the rate at which the thickness is increased due to the influence of humidity is only a value corresponding to the area ratio occupied by the corrugated cardboard. Therefore, the increase in the thickness of the corrugated cardboard material that makes up the composite buffer section 53, taking into account the influence of humidity, can be kept small. This makes it possible to make the buffer section 50 thinner. As a result, the size of the package 10 can be made smaller than when the shock absorbing section is made of foamed resin alone.

[0054] <Effects of the embodiment> Therefore, according to this embodiment, the following effects can be obtained. (1) The cushioning material 40 buffers an external force applied to the electronic device 100. The cushioning material 40 includes a support plate 42 and a buffering section 50. The support plate 42 is a member for supporting the electronic device 100. The buffering section 50 is provided on the support plate 42 and buffers the external force applied to the electronic device 100. The buffering section 50 includes a first buffering section 51 and a second buffering section 52. The first buffering section 51 has a first surface 61 fixed to the support plate 42 and a second surface 62 facing the electronic device 100. The second buffering section 52 has a third surface 63 fixed to the support plate 42 and a fourth surface 64 facing the electronic device 100. In a graph in which the vertical axis represents the external force applied to the electronic device 100 and the horizontal axis represents the time since the external force began to be applied to the electronic device 100, the first buffering section 51 and the second buffering section 52 have different waveforms. According to this configuration, by arranging the first buffer section 51 and the second buffer section 52, which have different types of waveforms, side by side, a highly versatile buffer material 40 can be provided. For example, the area ratio can be easily changed, facilitating fine adjustment of the buffer characteristics. Furthermore, it is also easy to reduce the thickness of the buffer sections 51, 52. Therefore, a highly versatile buffer material 40 that can be made thinner can be provided. As a result, the packaging material 20 can be made smaller without reducing the cushioning performance. As a result, transportation costs and the cost of the packaging material 20 can be reduced.

[0055] (2) The first buffering section 51 and the second buffering section 52 are arranged in contact with each other. This configuration reduces the possibility of a situation in which force is applied to only one of the first buffering section 51 and the second buffering section 52.

[0056] (3) Either the first buffer section 51 or the second buffer section 52 is arranged so that the other is surrounded by the first buffer section 51. This configuration can prevent a gap from being created between the first buffer section 51 and the second buffer section 52 due to an external force.

[0057] (4) The second surface 62 is flush with the fourth surface 64. This configuration reduces the possibility of a situation in which force is applied to only one of the first buffering portion 51 and the second buffering portion 52. (5) The first buffering portion 51 includes a material having a trapezoidal waveform, and the second buffering portion 52 includes a material having a half-sine waveform. This configuration allows the weaknesses of the creep characteristics and the buffering characteristics to be compensated for, thereby providing a buffering material 40 having both characteristics.

[0058] (6) The first buffer portion 51 is made of corrugated cardboard, and the second buffer portion 52 is made of foamed resin. This configuration uses two types of materials that are easy to obtain from the standpoints of price and mass production, making it easy to mass-produce the versatile buffer portion 40 at low cost.

[0059] (7) The cushioning material 40 includes a support plate 42 and a buffer section 50. The support plate 42 is a member for supporting the electronic device 100. The buffer section 50 is provided on the support plate 42 and buffers external forces applied to the electronic device 100. The buffer section 50 includes a first buffer section 51 and a second buffer section 52. The first buffer section 51 has a first surface 61 fixed to the support plate 42 and a second surface 62 facing the electronic device 100. The second buffer section 52 has a third surface 63 fixed to the support plate 42 and a fourth surface 64 facing the electronic device 100. In a stress-strain diagram where the vertical axis represents the compressive stress σ applied to the buffer section and the horizontal axis represents the strain ε applied to the buffer section, the following (a) to (c) are satisfied: (a) The maximum stress σ1 in the elastic region EA of the first buffering section 51 is greater than the maximum stress σ2 in the elastic region EA of the second buffering section 52. (b) The slope indicating the ratio of stress σ to strain ε in the plastic region PA of the first buffer section 51 is zero or close to zero, and the slope indicating the ratio of stress σ to strain ε in the plastic region PA of the second buffer section 52 is a positive value greater than the slope of the first buffer section 51. (c) The maximum stress σ3 in the elastic region EA of the composite buffer section 53, which is formed by arranging the first buffer section 51 and the second buffer section 52 in parallel in a direction facing the electronic device 100, is greater than the maximum stress σ2 of the second buffer section 52, and the slope of the composite buffer section 53 in the plastic region PA is a larger positive value than the slope of the first buffer section 51.

[0060] According to this configuration, by arranging the first buffer section 51 and the second buffer section 52 in parallel, each containing different materials that are excellent in either the maximum stress or the slope of the plastic zone PA, it is possible to provide a highly versatile packaging material 20. Furthermore, since the area ratio can be easily changed, it is easy to fine-tune the buffering characteristics.

[0061] (8) The first buffer portion 51 is made of corrugated cardboard, and the second buffer portion 52 is made of foamed resin. With this configuration, by combining buffer materials 40 that are easy to obtain from the standpoints of price and mass production, it is possible to provide a packaging material 20 that is highly versatile and has a high buffering effect. Furthermore, when the corrugated cardboard is made of paper, it is possible to provide a buffer material 40 that is resistant to moisture (humidity) depending on the proportion of foamed resin.

[0062] (9) The electronic device 100 is a recording device 110. With this configuration, the recording device 110 can be protected from impacts. (10) The packaging material 20 includes a packaging box 30 capable of housing the electronic device 100, and a cushioning material 40. According to this configuration, the electronic device 100 housed in the packaging box 30 can be effectively protected from impact by the cushioning material 40.

[0063] (11) The package 10 includes the packaging material 20 and the electronic device 100. This configuration can protect the electronic device 100 in the package 10 from impact. <Example of change> The above embodiment can be modified to the following modified examples. Furthermore, further modified examples can be formed by appropriately combining the above embodiment and the modified examples shown below, or by appropriately combining the modified examples shown below.

[0064] Either the first buffer section 51 or the second buffer section 52 may be arranged so that the other is surrounded by the other. The relationship between the first buffer section 51 and the second buffer section 52 may be reversed from that of the above embodiment. For example, as shown in FIGS. 11 and 12, one second buffer section 52 may be arranged so that the other first buffer section 51 is surrounded by the other first buffer section 51. With this configuration, it is easier to prevent the electronic device 100 from hitting the second buffer section 52 before the first buffer section 51, compared to the above embodiment.

[0065] The second buffer section 52 made of a foamed resin material in the above embodiment may be replaced with a second buffer section 54 made of corrugated cardboard as shown in FIGS. 13 and 14 . As shown in FIGS. 13 and 14 , the first buffer section 51 and the second buffer section 54 may both be made of the same material, i.e., corrugated cardboard. That is, the first buffer section 51 made of corrugated cardboard and the second buffer section 54 made of corrugated cardboard may be arranged in parallel in a direction facing the electronic device 100 to form a composite buffer section 55. The buffer section 50 may then be formed from the composite buffer section 55. Even if both are made of corrugated cardboard, it is sufficient that the first buffer section 51 and the second buffer section 54 have different waveforms in graphs showing the relationship between the acceleration G of an external force applied to the electronic device 100 and time t when an impact is applied. Specifically, it is sufficient that the waveform in the graph showing the relationship between the acceleration G of an external force applied to the electronic device 100 via the first buffer section 51 and time t is a trapezoidal wave. It is sufficient that the waveform of a graph showing the relationship between the acceleration G of an external force applied to the electronic device 100 via the second buffer section 54 and time t is a half-sine wave. That is, the first buffer section 51 includes a material that forms a trapezoidal wave waveform, and the second buffer section 54 includes a material that forms a half-sine wave waveform. Furthermore, it is sufficient that the first buffer section 51, the second buffer section 54, and the composite buffer section 55 satisfy the conditions (a) to (c) described in the above embodiment in a stress-strain diagram showing the relationship between the compressive stress and strain ε. The first buffer section 51 and the second buffer section 54 may be disposed in contact with each other. Furthermore, either the first buffer section 51 or the second buffer section 54 may be disposed surrounded by the other. In the example shown in FIG. 13, one first buffer section 51 is disposed surrounded by the other second buffer section 54. The second surface 62 and the fourth surface 64 may be flush with each other. As shown in FIG. 14, the corrugated cardboard material constituting the first buffer section 51 has the same structure as in the above-described embodiment. That is, the corrugated cardboard material is a structure in which multiple layers of corrugated cardboard sheets 51A having the same layer structure are laminated together. In other words, the material of the first buffer section 51 is a corrugated cardboard material formed by laminating multiple layers of corrugated cardboard sheets 51A having the same layer structure and the same hardness (compression strength). Therefore, the waveform of the first buffer section 51 is a trapezoidal wave. On the other hand, the corrugated cardboard material that is the material of the second buffer section 54 is a structure in which multiple layers of corrugated cardboard sheets 54A having different hardness (compression strength) are laminated together.In particular, the corrugated cardboard material used for the second buffer section 54 includes a multi-layered cardboard sheet 54A with a graded hardness ranging from soft to hard. The thickness of each layer of the multi-layered cardboard sheet 54A, which is one factor that determines the hardness, varies. Meanwhile, the waveform of the second buffer section 54, which is made of a cardboard material formed by stacking multiple layers of cardboard sheets 54A with graded hardness, is a half-sine wave. This is because the multiple layers of cardboard sheets 54A with different hardnesses are arranged in series facing the electronic device 100. The individual waveforms of each layer of the cardboard sheet 54A are trapezoidal waves with different heights. These trapezoidal waves with different heights are combined to form a pseudo-half-sine wave similar to the half-sine wave shown in FIG. 10 .

[0066] In the above embodiment, as shown in FIG. 3 , the first buffer section 51 and the second buffer section 52 have the same rectangular outer shape. However, different shapes may be combined. That is, the first buffer section 51 (i.e., the inner shape of the second buffer section 52) and the second buffer section 52 may have different shapes. For example, the first buffer section 51 may have a circular outer shape and the second buffer section 52 may have a rectangular outer shape. Conversely, the first buffer section 51 may have a rectangular outer shape and the second buffer section 52 may have a circular outer shape. Furthermore, the shapes may be a combination of different shapes such as a circle, triangle, square, pentagon, hexagon, ellipse, or diamond.

[0067] In the above embodiment, the second buffer section 52 surrounding the periphery of the first buffer section 51 is configured from one member, but it may be configured from multiple members. In other words, the second buffer section 52 may be configured from multiple members arranged to surround the first buffer section 51.

[0068] Either the first buffer section 51 or the second buffer sections 52, 54 does not have to be surrounded by the other. For example, the first buffer section 51 and the second buffer sections 52, 54 may both be rectangular plates and may be arranged with only one side surface in contact with each other.

[0069] The second surface 62 and the fourth surface 64 do not have to be flush with each other. For example, the thickness of the second buffering portions 52 and 54 may be greater than the thickness of the first buffering portion 51, or conversely, the thickness of the first buffering portion 51 may be greater than the thickness of the second buffering portions 52 and 54.

[0070] The first buffer section 51 and the second buffer sections 52, 54 do not have to be arranged in contact with each other. For example, the first buffer section 51 and the second buffer sections 52, 54 may be arranged in positions spaced apart from each other and parallel to the direction facing the electronic device 100. In short, the positions at which the first buffer section 51 and the second buffer section 52 are arranged on the fixed surface 42P of the support plate 42 may be any positions where the second surface 62 and the fourth surface 64 can face one of the outer peripheral surfaces of the electronic device 100.

[0071] The number of support plates 42 that the support section 41 has is not limited to four and may be changed to another number. For example, the number of support plates 42 may be one, two, or three. For example, when there are two support plates 42, two support plates 42 are arranged perpendicular to each other. When there are three support plates 42, three support plates 42 are arranged perpendicular to each other. Furthermore, the number of support plates 42 may be five or six. When there are five or six support plates 42, the packaging box 30 may also serve as the support plates 42. The buffer section 50 may be directly fixed to the inner surface of the packaging box 30. When there are five support plates 42, five surfaces of the packaging box 30 other than the flaps 32 serve as support plates 42, and the buffer section 50 is fixed to the inner surfaces of these five surfaces (support plates 42).

[0072] The second surface 62 and the fourth surface 64 being flush does not necessarily mean that the difference in height between the surfaces in the Z1 direction is 0 mm. For example, even if the positions in the Z1 direction are shifted within a range where the timing at which the electronic device 100 hits the second surface 62 and the fourth surface 64 can be considered to be substantially simultaneous, this still falls within the flush state. In this case, the second surface 62 and the fourth surface 64 may be considered flush if the difference in length between them is within 5% of the thickness (Z1 direction dimension) of the buffer unit 50. Note that the thickness of the buffer unit 50 is typically in the range of 1 to 20 mm, depending on the size, shape, and weight of the electronic device 100. In this example, the second surface 62 and the fourth surface 64 may be considered flush if the difference in size in the Z1 direction between them is within the range of 0.05 mm to 1 mm.

[0073] The second surface 62 and the fourth surface 64 do not have to be flush. It is sufficient that a certain level of cushioning effect is obtained, although it will be less than if they were flush. Furthermore, if there is a step between the opposing surfaces on the electronic device 100 side, the second surface 62 and the fourth surface 64 may have a height difference corresponding to the step. Furthermore, to improve creep characteristics, the second surface 62 of the first buffering section 51 may be higher than the fourth surface 64 of the second buffering section 52. Furthermore, to improve cushioning characteristics, the fourth surface 64 of the second buffering section 52 may be higher than the second surface 62 of the first buffering section 51.

[0074] The number of buffer sections 50 (composite buffer sections 53) fixed to one support plate 42 may be changed as appropriate. The number of buffer sections 50 per support plate may be one, two, three, four or more. In addition, in the case of a support section 41 having multiple support plates 42, the number of buffer sections 50 may be set for each support plate 42. The number of buffer sections 50 may be the same for all support plates 42, or the number of buffer sections 50 may be set according to the area of ​​the fixed surface 42P of the support plate 42.

[0075] In the above-described embodiment and the modified examples shown in Figures 11 and 13, the cardboard may be made of synthetic resin instead of paper. In this case, in the modified examples shown in Figures 13 and 14, one of the cardboards of the first buffer section 51 and the second buffer section 52 may be made of paper and the other may be made of synthetic resin.

[0076] The number of buffer sections 50 provided in the support section 41 is not limited to a plurality, and may be one. Furthermore, if the support section 41 has a plurality of support plates 42, the buffer section 50 made of the composite buffer section 53 may be fixed to only one of the support plates 42. In this case, buffer sections made of a buffer material other than the composite buffer section 53 may be fixed to the other support plates 42.

[0077] <Additional Notes> The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below. (A) The cushioning material is a cushioning material that cushions an external force applied to an electronic device, the cushioning material comprising: a support plate for supporting the electronic device; and a cushioning section provided on the support plate that cushions the external force applied to the electronic device, the cushioning section comprising: a first cushioning section having a first surface fixed to the support plate and a second surface facing the electronic device; and a second cushioning section having a third surface fixed to the support plate and a fourth surface facing the electronic device, wherein in a graph in which the vertical axis represents the external force applied to the electronic device and the horizontal axis represents the time from when the external force begins to be applied to the electronic device, the first cushioning section and the second cushioning section have different waveform types.

[0078] According to this configuration, by arranging the first buffer section and the second buffer section, which have different types of waveforms, side by side, a highly versatile buffer material can be provided. For example, the area ratio can be easily changed, facilitating fine adjustment of the buffer characteristics. Furthermore, it is also easy to reduce the thickness of the buffer section, allowing the buffer material to be made thinner. Therefore, a highly versatile buffer material that can be made thinner can be provided. As a result, the packaging material can be made smaller without reducing the cushioning performance. As a result, transportation costs and packaging material costs can be reduced.

[0079] (B) A cushioning material that cushions an external force applied to an electronic device, the cushioning material comprising: a support plate for supporting the electronic device; and a cushioning section provided on the support plate that cushions the external force applied to the electronic device, the cushioning section comprising: a first cushioning section having a first surface fixed to the support plate and a second surface facing the electronic device; and a second cushioning section having a third surface fixed to the support plate and a fourth surface facing the electronic device, wherein in a stress-strain diagram with the vertical axis representing compressive stress applied to the cushioning section and the horizontal axis representing strain applied to the cushioning section, (a) the maximum stress in the elastic region of the first cushioning section is (b) the slope indicating the ratio of stress to strain in the plastic region of the first buffer section is zero or close to zero, and the slope indicating the ratio of stress to strain in the plastic region of the second buffer section is a positive value greater than the slope of the first buffer section; and (c) the maximum stress in the elastic region of a composite buffer section formed by arranging the first buffer section and the second buffer section in parallel in a direction facing the electronic device is greater than the maximum stress of the second buffer section, and the slope in the plastic region of the composite buffer section is a positive value greater than the slope of the first buffer section.

[0080] According to this configuration, by arranging the first buffer section and the second buffer section side by side, each containing a different material that excels in either the maximum stress or the slope of the plastic region, a highly versatile packaging material can be provided. Furthermore, since the area ratio can be easily changed, fine adjustment of the buffering characteristics is easy. Furthermore, since it is easy to reduce the thickness of the buffer section, the buffer material can be made thinner. Therefore, a highly versatile and thin-profile buffer material can be provided.

[0081] (C) In the cushioning material described in (A) or (B) above, the first cushioning section and the second cushioning section may be arranged in contact with each other. This configuration reduces the occurrence of a situation in which force is applied to only one of the first cushioning section and the second cushioning section.

[0082] (D) In ​​the cushioning material according to any one of (A) to (C) above, one of the first and second cushioning sections may be arranged so as to be surrounded by the other. This configuration can prevent a gap from being generated between the first and second cushioning sections due to an external force.

[0083] (E) In the cushioning material according to any one of (A) to (D) above, the second surface and the fourth surface may be flush with each other. This configuration reduces the occurrence of a situation in which force is applied to only one of the first and second cushioning sections.

[0084] (F) In the cushioning material described in any one of (A) to (E) above, the first cushioning section may contain a material whose waveform is a trapezoidal wave, and the second cushioning section may contain a material whose waveform is a half-sine wave. With this configuration, it is possible to provide a cushioning material that combines creep characteristics and cushioning characteristics by compensating for each other's weaknesses.

[0085] (G) In the cushioning material described in any one of (A) to (F) above, the first cushioning portion may be made of corrugated cardboard, and the second cushioning portion may be made of foamed resin. This configuration uses two types of materials that are easy to obtain from the standpoints of cost and mass production, thereby providing a cushioning material that is highly versatile and has a high cushioning effect. Furthermore, if the corrugated cardboard material is made of paper, a cushioning material that is resistant to moisture (humidity) can be provided depending on the proportion of foamed resin.

[0086] (H) In the cushioning material according to any one of (A) to (F) above, the electronic device may be a recording device. With this configuration, the recording device can be protected from impacts. (I) The packaging material includes a packaging box capable of housing the electronic device, and the cushioning material according to any one of (A) to (H) above. With this configuration, the electronic device housed in the packaging box can be effectively protected from impact by the cushioning material.

[0087] (J) A packaged product includes the packaging material described in (H) above and the electronic device. With this configuration, the electronic device inside the packaged product can be protected from impact. [Explanation of symbols]

[0088] 10...packaged item, 20...packaging material, 30...packaging box, 31...main body, 32...flap, 33...opening, 40...cushioning material, 40A...cushioning material, 40B...cushioning material, 40C...cushioning material, 40D...cushioning material, 41...support part, 42...support plate, 42A...first support plate, 42B...second support plate, 42C...third support plate, 42D...fourth support plate, 42P...fixed surface, 50...cushioning part, 51...first cushioning part, 51A...cardboard sheet, 5 2...second buffer section, 53...composite buffer section, 54...second buffer section, 54A...cardboard sheet, 55...composite buffer section, 61...first surface, 62...second surface, 63...third surface, 64...fourth surface, 100...electronic device, 110...recording device, σ...stress (compressive stress), t...time, σ1...maximum stress, σ2...maximum stress, σ3...maximum stress, EA...elastic range, PA...plastic range, NA...unusable range, UA...usable range, G...acceleration.

Claims

1. A cushioning material that cushions external forces applied to an electronic device, The buffer material is a support plate for supporting the electronic device; a buffer portion provided on the support plate for buffering an external force applied to the electronic device, The buffer section is a first buffer section having a first surface fixed to the support plate and a second surface facing the electronic device; a second buffer section having a third surface fixed to the support plate and a fourth surface facing the electronic device; A cushioning material characterized in that, in a graph in which the vertical axis represents the external force applied to the electronic device and the horizontal axis represents the time since the external force began to be applied to the electronic device, the types of waveforms of the graph for the first buffer section and the second buffer section are different.

2. The cushioning material according to claim 1 , wherein the first cushioning portion and the second cushioning portion are disposed in contact with each other.

3. 2. The cushioning material according to claim 1, wherein one of the first cushioning section and the second cushioning section is arranged so as to be surrounded by the other.

4. 3. The cushioning material according to claim 2, wherein the second surface and the fourth surface are flush with each other.

5. 2. The cushioning material according to claim 1, wherein the first buffering portion includes a material having a waveform that forms a trapezoidal wave, and the second buffering portion includes a material having a waveform that forms a half sine wave.

6. 2. The cushioning material according to claim 1, wherein the first cushioning portion is made of a corrugated cardboard material, and the second cushioning portion is made of a foamed resin material.

7. A cushioning material that cushions external forces applied to an electronic device, The buffer material is a support plate for supporting the electronic device; a buffer portion provided on the support plate for buffering an external force applied to the electronic device, The buffer section is a first buffer section having a first surface fixed to the support plate and a second surface facing the electronic device; a second buffer section having a third surface fixed to the support plate and a fourth surface facing the electronic device; In a stress-strain diagram in which the vertical axis represents the compressive stress applied to the buffer portion and the horizontal axis represents the strain applied to the buffer portion, (a) the maximum stress in the elastic region of the first buffering portion is greater than the maximum stress in the elastic region of the second buffering portion; (b) a slope indicating the ratio of stress to strain in the plastic region of the first buffering portion is zero or close to zero, and a slope indicating the ratio of stress to strain in the plastic region of the second buffering portion is a positive value greater than the slope of the first buffering portion; (c) A cushioning material characterized in that the maximum stress in the elastic region of a composite cushioning section formed by arranging the first cushioning section and the second cushioning section in parallel in a direction facing the electronic device is greater than the maximum stress of the second cushioning section, and the inclination in the plastic region of the composite cushioning section takes a greater positive value than the inclination of the first cushioning section.

8. 8. The cushioning material according to claim 7, wherein the first cushioning portion is made of a corrugated cardboard material and the second cushioning portion is made of a foamed resin material.

9. 2. The cushioning material according to claim 1, wherein the electronic device is a recording device.

10. a packaging box capable of housing the electronic device; A packaging material comprising the cushioning material according to any one of claims 1 to 9.

11. A package comprising the packaging material according to claim 10 and the electronic device.

Images