Patent Description:
Reduction of the use amount of single-use plastics and the marine plastic waste pollution which has been at issue in recent years have become challenges to realize a circular society aiming at a sustainable global environment. In addressing these challenges, use of plastic packaging materials derived from fossil resources is increasingly restricted. Thus, the use value of molded pulp packaging materials having excellent resource recoverability and recyclability is further increasing.

In packaging materials made of molded pulp, there is already known a technology that absorbs vibration and falling impact that an object to be packaged may receive in a distribution process by a molded pulp impact absorbing material being deformed and crushed to reduce the impact, i.e., an impact acceleration (gravitational forces (G's)) applied to the object to be packaged.

However, as an impact characteristic specific to a molded pulp packaging material known in the art, a large impact force may be instantaneously applied to an object to be package. In such a case, particularly in a packaging material that accommodates precision equipment, there is a disadvantage that many portions of the internal structure of an object to be packaged may be deformed or damaged.

In addition, in a packaging material that accommodates precision equipment using a molded pulp impact absorbing material, there has been a disadvantage that the impact-resistant strength of the object to be packaged is low and the object to be packaged may be broken.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose background art to the invention.

In light of the above-described disadvantages, a purpose of the present disclosure is to provide an impact absorber that prevents a high impact force from being suddenly applied to a packaged object. Another purpose of the present disclosure is to provide an impact absorber that reduces impact acceleration applied to an object to be packaged.

To solve the above-described problems, an embodiment of the present disclosure provides an impact absorber including a three-dimensional structure according to independent claim <NUM>.

Another embodiment of the present disclosure provides an impact absorber including a three-dimensional structure according to independent claim <NUM>.

According to the present disclosure, it is possible to provide an impact absorber that prevents a high impact force from being suddenly applied to an object to be packaged. Further, according to the present disclosure, it is possible to provide another impact absorber that reduces impact acceleration applied to an object to be packaged.

Also, like or similar reference numerals designate identical or similar components throughout the several views.

However, the disclosure of the present specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.

Embodiments of the present disclosure are described below with reference to the attached drawings. In the drawings that illustrate embodiments of the present disclosure, like reference numerals are assigned as long as discrimination is possible to components such as members and component parts having a like function or shape. Thus, a description thereof is omitted once the description is provided.

A packaging material that packages an object to be packaged and an impact absorber that is disposed in the packaging material and absorbs an impact applied to the object to be packaged according to embodiments of the present disclosure are described in the following description. Further, a packaging material made of molded pulp as an example of the packaging material and an impact absorbing rib made of molded pulp as an example of the impact absorber are described as appropriate. In general, a packaging material made of molded pulp basically includes an impact absorbing rib having a cylindrical or prismatic structure to perform an impact absorbing function. In addition, an impact absorbing material made of molded pulp basically includes an impact absorbing rib having a cylindrical or prismatic structure to perform an impact absorbing function.

First, a description is given of a structure of an impact absorbing rib that reduces an impact applied to an inner structure of the object to be packaged, using a packaging material according to a control sample. <FIG> is a perspective view of a packaging material 200p made of molded pulp, according to a control sample of the present disclosure. <FIG> is a schematic perspective view of an impact absorbing rib 1p according to a control sample of the present disclosure. <FIG> is a schematic perspective view of an impact absorbing rib 2p according to another control sample of the present disclosure. The packaging material 200p includes the impact absorbing rib 1p made of molded pulp. The packaging material 200p includes an object accommodating space 210p indicated by a region surrounded by a broken line in <FIG>. The impact absorbing rib 1p has a three-dimensional structure in which a top surface is closed, a bottom surface is open, and the inside of the impact absorbing rib 1b is hollow in a cylindrical or prismatic structure.

It is already known that propagation and amplification characteristics inside the structure of an object to be packaged, when the object to be packaged receives an impact from an impact absorbing material, are determined from a relation between input impact characteristics and natural vibration characteristics of each member of the internal structure of the object to be packaged. More specifically, in precision equipment, it is known that an impact response magnification in the internal structure of the precision equipment is high when a large impact force as an input impact characteristic is instantaneously applied to the precision equipment.

<FIG> is a graph illustrating impact absorbing properties of a molded pulp impact absorbing material and a resin-foam impact absorbing material, according to the present embodiment. As illustrated in <FIG>, the impact characteristic applied to the object to be packaged via the molded pulp impact absorbing material has a characteristic that a large impact force is instantaneously applied to the object to be packaged. For this reason, when the object to be packaged is packaged with a molded pulp impact absorbing material, a large impact load is applied to the internal structure of the object to be packaged. Thus, there is a disadvantage that many parts of the internal structure of the object to be packaged may be deformed and broken. The resin foam impact absorbing material has a characteristic that the impact force increases relatively gradually. For this reason, the above-described disadvantage is unlikely to occur with the resin foam impact absorbing material.

The impact absorbing mechanism of the impact absorbing rib according to a control sample is described in the following description. <FIG> is a schematic perspective view of the impact absorbing rib 1p, according to the control sample. <FIG> is a cross-sectional view of the impact absorbing rib 1p cut along a line A-A illustrated in <FIG>. The impact absorbing rib 1p having a three-dimensional structure as illustrated in <FIG> is molded with a gradient of at least equal to or higher than <NUM> degrees for mold releasability when the impact absorbing rib 1p is fabricated.

<FIG> is a diagram illustrating a cross-sectional view of the impact absorbing rib 1p and the object to be packaged <NUM> that is in contact with the impact absorbing rib 1p, illustrating how side walls of the impact absorbing rib 1p are compressed or crushed, according to the control sample. <FIG> is a cross-sectional view of the impact absorbing rib 1p and the object to be packaged <NUM> that is in contact with the impact absorbing rib 1p, along the cut line A-A illustrated in <FIG> illustrates a state before the object to be packaged <NUM> receives an impact in a left side of <FIG> and another state after the object to be packaged <NUM> has received the impact in a right side. In <FIG>, a package cargo is employed. The package cargo packages the object to be packaged <NUM> with the packaging material that includes the impact absorbing rib 1p illustrated in <FIG> such that the object to be packaged <NUM> contacts the top surface of the impact absorbing rib 1p. <FIG> illustrates the state in which the impact absorbing rib 1p receives a load from the object to be packaged <NUM> when the package cargo receives an impact.

The impact absorbing mechanism of the impact absorbing rib 1p supports a dynamic load received from the object to be packaged <NUM>, which is generated when the object to be packaged <NUM> is dropped as a packaged cargo, mainly in cross-sectional areas of the side walls of the impact absorbing rib 1p. Thus, the impact absorbing mechanism of the impact absorbing rib 1p absorbs the impact by the stress generated when the side walls of the impact absorbing rib 1p are compressed or crushed, as in the compressed and crushed portion 15p illustrated in <FIG>.

The impact absorbing rib 1p according to the control sample is a molded pulp impact absorbing material made of paper that has a characteristic such that a large stress is instantaneously generated in the impact absorbing rib 1p, as illustrated in <FIG> as a characteristic of the compression stress of the molded pulp impact absorbing material. Accordingly, a large impact force is instantaneously applied to the object to be packaged <NUM>. Note that in <FIG>, the prismatic impact absorbing rib 1p is used to describe the control sample. However, the control sample can also be applied to the cylindrical impact absorbing rib 2p.

As a solution to the above-described disadvantage, an impact absorber according to an embodiment of the present disclosure has a structure that prevents an impact from being applied instantaneously to an object to be packaged, as characteristics of such an impact applied to the object to be packaged via a molded pulp impact absorbing material.

Each of the impact absorbing ribs 1p and 2p as examples of an impact absorber according to an embodiment of the present disclosure has a three-dimensional structure having a closed top surface, an open bottom, and a hollow inside. The top surface of the three-dimensional structure includes at least one recess <NUM> within an outline (or outer line) of the top surface of the three-dimensional structure, which is an outer line of the top surface.

Further, each of the impact absorbing ribs 1p and 2p is formed by, for example, molded pulp, i.e., molded pulp impact absorbing material.

<FIG> is a schematic perspective view of the impact absorbing rib <NUM> as an impact absorber according to the present embodiment. <FIG> is a schematic perspective view of the impact absorbing rib <NUM> as another impact absorber according to another one of the embodiments. Each of the impact absorbing rib <NUM> and the impact absorbing rib <NUM> as examples of the impact absorber according to the present embodiments has a three-dimensional structure in which a top surface is closed, a bottom surface is opened, and an inside of the structure is hollow. The top surface of the structure of the impact absorbing rib <NUM> and the impact absorbing rib <NUM> includes at least one recess <NUM>, one recess <NUM>, respectively, each of which fits inside an outline of the top surface of the structure, which is a line outside the top surface. Further, the impact absorbing ribs <NUM> and <NUM> are formed by, for example, molded pulp, i.e., molded pulp impact absorbing material. In <FIG>, the prismatic impact absorbing rib <NUM> provided with the recess <NUM> is illustrated. In <FIG>, the cylindrical impact absorbing rib <NUM> provided with a recess 11a is illustrated. The impact absorbing rib <NUM> is mainly described in the following description. However, the impact absorbing rib <NUM> has like features as the impact absorbing rib <NUM> unless otherwise specified. <FIG> is a schematic perspective view of the impact absorbing rib <NUM> illustrating an upper portion of the impact absorbing rib <NUM> in which the rigidity of the upper portion is reinforced, according to the present embodiment.

Such a structure as described above allows the rigidity of the upper portion of the impact absorbing rib <NUM> to be reinforced by the recess <NUM> that fits inside the outline of the top surface of the impact absorbing rib <NUM>. In <FIG>, a rigidity reinforced portion <NUM> in which the rigidity is reinforced is indicated by oblique lines. Accordingly, due to the impact absorbing mechanism of the impact absorbing rib <NUM>, the rigidity reinforced portion <NUM> allows the upper portion of the impact absorbing rib <NUM> to sink to a lower portion of the impact absorbing rib <NUM> while the upper portion having a high rigidity is not compressed and crushed and maintains a constant shape.

<FIG> is a schematic perspective view of the impact absorbing rib <NUM> according to the present embodiment. <FIG> is a diagram illustrating a cross-sectional view of the impact absorbing rib <NUM> cut along a line B-B illustrated in <FIG> and the object to be packaged <NUM> that is in contact with the impact absorbing rib <NUM>, illustrating how the impact absorbing mechanism of the impact absorbing rib <NUM> works when an impact is added to the impact absorbing rib <NUM>, according to the present embodiment. <FIG> illustrates a state before the impact absorbing rib 1p and the object to be packaged <NUM> receive an impact in a left side of <FIG> illustrates a state after the impact absorbing rib <NUM> and the object to be packaged <NUM> have received the impact in a right side of <FIG>. In <FIG>, a package cargo is employed. The package cargo packages the object to be packaged <NUM> with the packaging material that includes the impact absorbing rib <NUM> illustrated in <FIG> such that the object to be packaged <NUM> contacts the top surface of the impact absorbing rib <NUM>. <FIG> illustrates the state in which the impact absorbing rib <NUM> receives a load from the object to be packaged <NUM> when the package cargo receives an impact. As illustrated in <FIG>, the impact applied to the impact absorbing rib <NUM> generates a compressed and crushed portion <NUM> and a bent and buckled portion <NUM>. Thus, the impact absorbing rib <NUM> absorbs the impact.

At this time, in the impact absorbing rib <NUM>, a stress of bending and buckling of the bent and buckled portion <NUM> below the rigidity reinforced portion <NUM> and a stress of compression and crushing of the outer walls are generated in a combined manner. Note that the stress of bending and buckling of the bent and buckled portion <NUM> is typically smaller than the stress of compression and crushing of the outer walls. Accordingly, occurrence of a phenomenon in which a large impact force is instantaneously applied to the impact absorbing rib <NUM> is reduced. <FIG> is a graph illustrating a relation between an elapsed time and an impact force applied to the impact absorbing rib <NUM> according to the present embodiment and the impact absorbing rib 1p according to the control sample. <FIG> indicates that the impact force applied to the impact absorbing rib <NUM> according to the embodiment is lower than the impact force applied to the impact absorbing rib 1p according to the control sample which absorbs the impact by compression and crushing.

As described above, the impact absorbing rib <NUM> as an example of the impact absorber according to the present embodiment has a structure in which the stress of bending and buckling of the bent and buckled portion <NUM> below the rigidity reinforced portion <NUM> and the stress of compression and crushing of the outer walls are generated in a combined manner. Accordingly, a large impact load inside the object to be packaged, which is generated in a packaging material known in the art when a large impact force is instantaneously applied to the object to be packaged, can be reduced. Note that, in a case in which a recess 11x of an impact absorbing rib 1x is disposed so as to connect with the outline of the top surface of the impact absorbing rib 1x (see <FIG>), there is room for an upper portion of the impact absorbing rib 1x to be partially deformed. Accordingly, it is assumed that the upper portion of the impact absorbing rib 1x may not sink to a lower portion of the impact absorbing rib 1x while maintaining a constant shape. For this reason, preferably, the recess <NUM> is formed so as to fit inside the outline of the top surface of the impact absorbing rib <NUM>. <FIG> is a schematic perspective view of the impact absorbing rib 1x in which the recess 11x is disposed so as to connect with the outline of the top surface of the impact absorbing rib 1xEach one of the embodiments of the above-described impact absorbing ribs having a corresponding one of the recess is described in the following description.

In a first embodiment, an impact absorbing rib provided with more than two recesses is described. <FIG> is a schematic perspective view of an impact absorbing rib 1a according to the first embodiment of the present disclosure. The impact absorbing rib 1a includes two recess <NUM>. The rigidity of the impact absorbing rib 1a can be further reinforced by increasing the number of recess <NUM>.

In a second embodiment, modifications of the cross-sectional shape of the recess <NUM> are described. The cross-sectional shape of the recess <NUM> may be, for example, a U-shape, a C-shape, or a V-shape. The cross-sectional shape of the recess <NUM> is the shape of the recess of the recess <NUM> from the top surface of the impact absorbing rib <NUM> to the bottom of the recess <NUM>. For example, the cross-sectional shape of the recess <NUM> is a U-shape, a C-shape formed by wall surfaces and the bottom of the recess <NUM> or a V-shape formed by the wall surfaces of the recess <NUM>. Further, in the cross-sectional shape formed by the wall surfaces and the bottom of the recess <NUM>, the wall surfaces of the recess <NUM> may be inclined as in a V-shape. <FIG> are diagrams each illustrating the cross-sectional shape of the impact absorbing rib <NUM> according to the second embodiment.

In a third embodiment, modifications of the outer shape of the recess <NUM> are described. The shape of the recess <NUM> viewed from above may be any one of a polygonal shape, a circular shape, or an outer shape in which curved lines or straight lines are continuously connected in a wave shape. In the present embodiment, the shape of the recess <NUM> viewed from above is a same shape as the top surface of the impact absorbing rib <NUM>. For example, when the recess <NUM> deforms from the top surface of the impact absorbing rib <NUM> toward the bottom of the recess <NUM>, the shape of the bottom of the recess <NUM> may be different from the shape of the top surface of the impact absorbing rib <NUM>.

<FIG> are top views of the impact absorbing rib <NUM> each illustrating a shape of the top surface of the recess <NUM> provided for the impact absorbing rib <NUM> according to the third embodiment. In <FIG>, the outline of the top surface of the recess <NUM> is rectangular. In <FIG>, the outline of the top surface of the recess <NUM> is circular. Further, as a shape of the recess <NUM> viewed from above, <FIG> illustrates a quadrangle shape, <FIG> illustrates a circular shape, <FIG> illustrates an outer shape in which curved lines are continuously connected to each other in a wave shape, and <FIG> illustrates an outer shape in which straight lines are continuously connected to each other in a wave shape.

The shape of the recess <NUM> may be formed along the outline of the top surface of the impact absorbing rib <NUM>. For example, when the outline of the top surface of the impact absorbing rib <NUM> is a polygon, the shape of the recess <NUM> may be a polygon in a similar manner. When the outline of the top surface of the impact absorbing rib <NUM> is an ellipse, the shape of the recess <NUM> may be an ellipse in a similar manner. The outer shape of the top surface of the impact absorbing rib <NUM> that is continuous in a wave shape as illustrated in <FIG> may be a shape obtained by combining curved lines and straight lines in wave shape.

Such a configuration as described above allows to secure the rigidity of the impact absorbing rib <NUM> without fail. Note that, when the shape of recess <NUM> viewed from above is an outer shape continuous in a wave shape, the rigidity of the impact absorbing rib <NUM> is reinforced with respect to forces received from multiple directions. Accordingly, the rigidity of the impact absorbing rib <NUM> can be secured reliably. <FIG> are diagrams each illustrating a top surface of the impact absorbing rib <NUM> and illustrating a difference in rigidity of the impact absorbing rib <NUM> between the impact absorbing rib <NUM> that includes the recess <NUM> having a quadrangle outer shape and the impact absorbing rib <NUM> that includes the recess <NUM> having an outer shape continuous in a wave shape, according to the present embodiment.

For example, when a force is applied to the inside of the recess <NUM> having the outer shape continuous in the wave shape, the force is applied to protruding or curved portions of the recess <NUM>. Accordingly, the outer shape continuous in a wave shape (see <FIG>) of the recess <NUM> is less likely to be bent than a quadrangular shape of the recess <NUM> (see <FIG>).

In a fourth embodiment, the depth of the recess <NUM> is described. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating an internal structure of the recess <NUM> provided for the impact absorbing rib <NUM> according to the fourth embodiment. In the present embodiment, a depth hb of the recess <NUM> is a distance from the top surface of the impact absorbing rib <NUM> to the bottom of the recess <NUM>. A height ha of the impact absorbing rib <NUM> is a distance, i.e., a shortest distance, from the top surface of the impact absorbing rib <NUM> to the bottom surface of the impact absorbing rib <NUM>. A thickness t of the impact absorbing rib <NUM> is a thickness of the impact absorbing rib <NUM> as a three-dimensional structure having a hollow inside of the impact absorbing rib <NUM>. In addition, in a case in which the thickness t of the impact absorbing rib <NUM> is different depending on positions of the impact absorbing rib <NUM> as the three-dimensional structure, for example, a value in a range from a minimum value inclusive to a maximum value inclusive is used, and one value may not be defined. At this time, the value in a range from equal to or greater than the minimum value to equal to or smaller than the maximum value may be limited to the thickness of the top surface of the impact absorbing rib <NUM> or the thickness of the rigidity reinforced portion <NUM> (see <FIG>). <FIG> illustrates the thickness t of the impact absorbing rib <NUM> as an example.

In the impact absorbing rib <NUM>, the depth hb (see <FIG>) of the recess <NUM> may be approximately twice of or greater than the thickness t of the impact absorbing rib <NUM>. Such a configuration as described above allows the degree of rigidity enhancement to be reliably ensured, and the shape of the recess <NUM> to be precisely formed during fabrication of the recess <NUM> so as to reinforce the rigidity of the impact absorbing rib <NUM> as intended. This is because, when the depth hb of the recess <NUM> is set to be approximately twice of or smaller than the thickness t of the impact absorbing rib <NUM>, a desired shape for the recess <NUM> may not be formed due to, for example, variation when the impact absorbing rib <NUM> is fabricated.

On the other hand, in the impact absorbing rib <NUM>, the depth hb of the recess <NUM> may be set to be approximately half or smaller than the height ha of the impact absorbing rib <NUM>. When the depth hb of the recess <NUM> is too large, rigidity reinforced portions of the rigidity reinforced portion <NUM> that serve as supports of the rigidity reinforced portion <NUM> are long. Thus, the rigidity reinforced portion <NUM> is likely to fall. In the present embodiment, the rigidity reinforced portions of the rigidity reinforced portion <NUM> serve as side walls surrounding the periphery of the recess of the recess <NUM> and serve as supports for supporting the rigidity reinforced portion <NUM>. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating an internal structure of the recess <NUM>, illustrating a disadvantage that may occur when the recess <NUM> has a large depth, according to the present embodiment.

The depth hb of the recess <NUM> of the impact absorbing rib <NUM> is set as appropriate as described above. Accordingly, the impact absorbing rib <NUM> avoids the above-described disadvantage and performs the intended function of reinforcing the rigidity of the impact absorbing rib <NUM>. In addition, the impact absorbing rib <NUM> deforms approximately half of the height of the impact absorbing rib <NUM> to absorb the impact. Accordingly, when the impact absorbing rib <NUM> deforms, the recess <NUM> contacts the bottom of the impact absorbing rib <NUM>. Thus, a disadvantage that hinders the impact absorbing function of the impact absorbing rib 1can be prevented. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating an internal structure of the recess <NUM>, illustrating a disadvantage that may occur when the recess contacts the bottom of the impact absorbing rib <NUM>, according to the present embodiment.

As described above, preferably, the depth hb of the recess <NUM> is a length that is approximately twice or greater than the thickness t of the impact absorbing rib <NUM> and a length that is approximately half or smaller than the height ha of the impact absorbing rib <NUM>.

In a fifth embodiment, a distance between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is described. <FIG> is a top view of the impact absorbing rib <NUM> illustrating a shape of an outline of a top portion of the recess <NUM>, according to the fifth embodiment. In the impact absorbing rib <NUM> according to the fifth embodiment, preferably, a distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is set to be a length larger than twice the thickness t of the impact absorbing rib <NUM>. Such a configuration as described above allows the rigidity reinforced portion <NUM> to be likely to fall in a case in which the distance db between the outer shape of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is too short. Thus, the target function of the impact absorbing rib <NUM> can be prevented from being impaired. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating an internal structure of the recess <NUM> and illustrating a disadvantage that may occur when the distance between the outer shape of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is small, according to the present embodiment.

On the other hand, in the impact absorbing rib <NUM>, the distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> may be set to be a length that is half of or smaller than the length of one side of the outline of the top surface along a same direction as the distance db. Such a configuration as described above allows the distance db between the outline of the top surface and the recess <NUM> to be excessively long to generate a moment. Accordingly, the recess <NUM> is likely to be pushed in due to an influence of the moment. Thus, a disadvantage in which the target function of rigidity reinforcement of the impact absorbing rib <NUM> may not performed, can be prevented. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating an internal structure of the recess <NUM> and illustrating a disadvantage that may occur when a distance between the outer shape of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is large compared to a case illustrated in <FIG>, according to the present embodiment.

As described above, preferably, the distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> is a length that is approximately twice or greater than the thickness t of the impact absorbing rib <NUM> and a length that is smaller than approximately half of a width da of the top surface of the impact absorbing rib <NUM> (see <FIG>).

Note that in a case in which the distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> changes as in the case in which the recess <NUM> has the outline shape with continuous wave shape as described above. In such a case, for example, the minimum value of the distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> may be set to be a length approximately twice or greater than the thickness t of the impact absorbing rib <NUM>, and the maximum value of the distance db between the outline of the top surface of the impact absorbing rib <NUM> and the recess <NUM> may be set to a length smaller than approximately half of the width da of the top surface of the impact absorbing rib <NUM>.

In addition, preferably, a portion between the outline of the top surface of impact absorbing rib <NUM> and the recess <NUM> is a flat surface. <FIG> is a top view of an impact absorbing rib 1q illustrating a shape of an outline of the top portion of the recess <NUM>, according to the present embodiment. <FIG> is a schematic side view of the impact absorbing rib 1q of <FIG>, illustrating a disadvantage that may occur when the portion between the outline of the top surface of the impact absorbing rib 1q and the recess <NUM> is a convex shape. <FIG> illustrates a case in which the portion between the outline of the top surface of the impact absorbing rib 1q and the recess <NUM> has a convex shape with a protruding tip. In <FIG>, the position of the tip of the convex shape is indicated by a two-dot dashed line. As illustrated in <FIG>, in the case in which the portion between the outline of the top surface of the impact absorbing rib 1q and the recess <NUM> is not a plane but a convex shape, the upper portion of the impact absorbing rib 1q is likely to fall in directions indicated by arrows illustrated in <FIG> due to the load received from the object to be packaged <NUM>. Accordingly, the target function of rigidity reinforcement of the impact absorbing rib 1q cannot be performed.

In a sixth embodiment, outer shapes of the impact absorbing rib <NUM> and <NUM> are described with reference to <FIG>. The outer shape of the impact absorbing rib <NUM> or outer shape of the impact absorbing rib <NUM> as the three-dimensional structure having a hollow structure may be a prismatic shape or a columnar shape. <FIG> illustrates the impact absorbing rib <NUM> having the prismatic shape. <FIG> illustrates the impact absorbing rib <NUM> having the columnar shape.

The prismatic shape of the impact absorbing rib <NUM> is, for example, a truncated pyramid shape as illustrated in <FIG> or the prismatic shape. In addition, the shape of the top surface or the bottom surface of the impact absorbing rib <NUM> is the prismatic shape. The impact absorbing rib <NUM> may include a deformed portion such as an uneven shape formed by straight lines or curved lines in a part of the prismatic shape. The columnar shape of the impact absorbing rib <NUM> is, for example, a truncated cone, as illustrated in <FIG> or a circular column. Further, the shape of the top surface or the bottom surface of the impact absorbing rib <NUM> is basically a circular shape or an elliptical shape. The impact absorbing rib <NUM> may include a deformed portion formed by straight lines or curved lines in a part of the circular shape or the elliptical shape.

In a seventh embodiment, a molded pulp packaging material in which one of the impact absorbing ribs according to a corresponding one of the above embodiments is described. The packaging material according to the present embodiment includes such an impact absorbing rib at least at one position in the packaging material. Such a configuration as described above allows the above-described rigidity enhancement function of the impact absorbing rib to be attained.

In addition, in the packaging material <NUM>, the impact absorbing rib <NUM> may be disposed such that the top surface of the impact absorbing rib <NUM> contacts the object to be packaged <NUM>. <FIG> is a perspective view of a packaging material <NUM> in which the impact absorbing rib <NUM> is disposed such that the top surface of the impact absorbing rib <NUM> contacts the object to be packaged <NUM>, according to the present embodiment. In the packaging material <NUM>, when the object to be packaged <NUM> is accommodated in an object to be packaged accommodating space <NUM>, the top surface of the impact absorbing rib <NUM> on which the recess <NUM> is disposed contacts the object to be packaged <NUM>. Such a configuration as described above allows the object to be packaged <NUM> to be accommodated in an effective manner such that a load is applied to intended positions of the object to be packaged <NUM>.

Further, the packaging material <NUM> may include the impact absorbing rib <NUM> such that an opening surface, i.e., the bottom surface, of the impact absorbing rib <NUM> contacts the object to be packaged <NUM>. <FIG> is a perspective view of the packaging material <NUM> in which the impact absorbing rib <NUM> is disposed such that the opening surface, i.e., the bottom surface, of the impact absorbing rib <NUM> contacts the object to be packaged <NUM>, according to the present embodiment. <FIG> is a perspective view of the packaging material <NUM> viewed from a reverse side of the object to be packaged accommodating space <NUM> in a state in which the top surface of the impact absorbing rib <NUM> on which the recess <NUM> is disposed in the packaging material <NUM>. Such a configuration as described above allows a surface of the object to be packaged accommodating space <NUM> and a side surface of the object to be packaged <NUM> to surface contact each other, when the side surface of the object to be packaged <NUM> is flat. Thus, the object to be packaged <NUM>, such as a product, can be stably held in the packaging material <NUM>. In addition, the packaging material <NUM> described above may be used, for example, to accommodate an imaging system product.

As described in each of the above embodiments, each one of the impact absorbing ribs as an example of the impact absorber according to the corresponding one of the embodiments of the present disclosure and the packaging material <NUM> that includes the impact absorbing rib have a structure in which a large impact is not instantaneously applied to the object to be packaged <NUM>. Accordingly, an effect that solves a disadvantage in which a large impact load is applied to the internal structure of the object to be packaged and many parts of the internal structure of the object to be packaged may be deformed and broken can be exhibited. In addition, due to the above-described effect, the quality as a packaging material for protecting an object to be packaged is significantly enhanced, which leads to delivery of a product to a customer without breakage. Further, solving the disadvantages that are inherent in the molded pulp impact absorbing materials known in the art allows to promote the use of materials having desirable resource recovery and recycling properties. Thus, the degree of contribution of using the above-described packaging material toward the realization of the circular society and the solving of plastic environmental disadvantages can be enhanced.

Results of a test using the impact absorbing ribs according to the above embodiments and the control sample are described in the following description.

In the test, the spectral response acceleration of the object to be packaged <NUM> was measured using the packaging material that includes the impact absorbing rib according to the control sample and the packaging material that includes the impact absorbing rib according to one of the above-described embodiments of the present disclosure. <FIG> each illustrate the impact absorbing rib 2p and the impact absorbing rib <NUM>, respectively, used in the test. <FIG> is a diagram illustrating how the test is conducted using a simple dynamic model.

As an impact absorbing rib according to the control sample, the truncated cylindrical impact absorbing rib 2p having a basic structure known in the art was used for the test. As an impact absorbing rib according to one of the embodiments, the impact absorbing rib <NUM> having a truncated quadrangular pyramid shape provided with the recess <NUM> was used for the test. The spectral response acceleration of the impact applied to the impact absorbing rib 2p or the impact absorbing rib <NUM> was measured under the following test conditions.

<FIG> is a table illustrating the test results of the impact absorbing ribs 2p according to the control sample and the impact absorbing ribs <NUM> according to one of the embodiments of the present disclosure. Five tests from N1 to N5 (test number) were conducted to measure the spectral response accelerations (G's) of the impact applied to the product external component and the spectral response accelerations (G's) of the impact applied to internal components of a product, i.e., the object to be packaged. The spectral response accelerations (G's) of the impact applied to external components of the product were divided by the spectral response accelerations (G's) of the impact applied to the internal components of the product to calculate the internal response amplification factors, i.e., impact amplification factors, of the spectral response accelerations (G's) of the impact. The internal response amplification factor of the spectral response accelerations (G's) of the impact was <NUM> times at the maximum in the impact absorbing rib 2p according to the control sample. On the other hand, the internal response amplification factor of the spectral response accelerations (G's) of the impact was <NUM> times at the maximum in the impact absorbing rib <NUM> that includes the recess <NUM> according to one of the embodiments. Thus, it was confirmed that a large reduction of the impact can be obtained with the impact absorbing rib <NUM> according to the embodiment.

The impact absorbing mechanism of the impact absorbing rib 1p according to the control sample as previously illustrated in <FIG> is described below. An example in which the side walls of the impact absorbing rib 1p according to the control sample are compressed or crushed is described with reference to <FIG> is a schematic perspective view of the impact absorbing rib 1p according to the control sample. <FIG> is a diagram illustrating a cross-sectional view of the impact absorbing rib 1p and the object to be packaged <NUM> that is in contact with the impact absorbing rib 1p, illustrating the impact absorbing rib 1p and the object to be packaged <NUM> in a state after the object to be packaged <NUM> has received the impact in a right part of <FIG>. In <FIG>, a package cargo that packages the object to be packaged <NUM> with the packaging material <NUM> that includes the impact absorbing rib 1p illustrated in <FIG> in which the impact absorbing rib 1p is disposed such that the object to be packaged <NUM> contacts the top surface of the impact absorbing rib 1p is used for description.

In general, a basic formula below is used in designing the impact absorbing mechanism.

<FIG> is a graph illustrating a relation between a distortion amount ε and an impact absorption coefficient C, according to the present embodiment. As expressed by the above-described basic formula, the value of the impact absorption coefficient C determined by the stress characteristics of the impact absorbing material is targeted to be low. On the other hand, disposing the object to be packaged <NUM> inside the packaged cargo such that the outer shape of the object to be packaged <NUM> does not contact the bottom of the packaged cargo is taken into consideration in advance. Then, the instantaneous distortion amount of the impact absorbing rib 1p is designed to be typically <NUM> to <NUM> by adjusting the above-described cross-sectional area of the side walls of the impact absorbing rib 1p as a supporting area of the load of the object to be packaged <NUM>. <FIG> is a diagram illustrating how the object to be packaged <NUM> is placed relative to impact absorbing materials, according to the present embodiment. In designing an impact absorbing mechanism, the impact absorbing materials are arranged to generate a gap between the object to be packaged <NUM> and a bottom of an outer box of the package cargo which accommodates the object to be packaged <NUM> such that an outer shape of the object to be packaged <NUM> does not contact the bottom of the outer box of the package cargo when the packaged cargo that accommodates the object to be packaged <NUM> receives an impact.

When the above-described structure and design technology of the impact absorbing rib are employed, a reduction limit value of impact acceleration in an impact absorbing rib having a form known in the art such as the impact absorbing rib 1p according to the control sample, is determined. For this reason, desirably, a new impact absorbing rib structure having a lower impact-absorption coefficient value than the impact absorbing rib structure known in the art is found to further enhance the impact-absorbing function. In addition, in the impact absorbing rib 1p according to the control sample, the side walls of the impact absorbing rib 1p are compressed or crushed due to the natural dynamic load to generate stress to absorb the impact, when the impact absorbing rib 1p receives an unbalanced load from the object to be packaged <NUM>. However, at this time, the structure of the impact absorbing rib 1p is likely to bend, and there is a disadvantage in which the stress to absorb the impact may be generated.

<FIG> is a schematic cross-sectional view of the impact absorbing rib 1p and the object to be packaged <NUM> illustrating how the side walls of the impact absorbing rib 1p are compressed or crushed when the impact absorbing rib 1p receives an unbalanced load from the object to be packaged <NUM>, according to the control sample. <FIG> illustrates a cross section of the impact absorbing rib 1p and the object to be packaged <NUM> that is in contact with the impact absorbing rib 1p cut along the line A-A illustrated in <FIG>. <FIG> illustrates a state before the impact absorbing rib 1p and the object to be packaged <NUM> receive an impact in a left side of <FIG> and illustrates a state after the impact absorbing rib <NUM> and the object to be packaged <NUM> have received the impact in a right side of <FIG>. In <FIG>, a package cargo similar to the package cargo of <FIG> is used. As illustrated in <FIG>, an energy absorption amount originally consumed by compression or crushing of the side walls of the impact absorbing rib 1p is consumed by a bending stress which consumes a relatively small energy absorption amount. Thus, impact absorption properties of the impact absorbing rib 1p are impaired. Accordingly, the structure of the impact absorbing rib 1p is excessively distorted and the impact acceleration applied to the object to be packaged <NUM> is increased. Note that the above-described disadvantage frequently occurs due to variations of posture of the object to be packaged <NUM> every time the object to be packaged <NUM> is dropped or variations of the position of the center of gravity of the object to be packaged <NUM>. Thus, the impact absorption properties of the impact absorbing rib 1p are impaired. Note that the description is given using the impact absorbing rib 1p having the rectangular column shape in <FIG> and <FIG>. However, the above description applies to the impact absorbing rib 2p having the columnar shape.

The impact absorbing ribs, as examples of the impact absorber according to the embodiments of the present disclosure, have a structure that reduces impact acceleration applied to an object to be packaged in a molded pulp packaging material to solve the above-described disadvantage. Such an impact absorber has a structure in which a groove is disposed on a top surface of the impact absorber and a specific size of the groove is employed. Such a structure of the impact absorber eliminates loss of impact energy absorption amount when an impact absorber including an impact absorbing rib known in the art that has a posture for supporting a biased load and reliably exhibits a compression or crushing mechanism.

The structure and the function of the impact absorbing ribs as examples of the impact absorber according to the embodiments of the present disclosure is described in the description below. Each of the impact absorbing ribs has a three-dimensional structure in which a top surface of the structure is closed, a bottom surface of the structure is opened, and the inside of the structure is hollow, in which at least one groove is disposed on the top surface of the structure so as to connect one end and another end of an outline, i.e., a line outside the top surface, of the top surface. Further, each of the impact absorbing ribs is formed by, for example, molded pulp, i.e., molded pulp impact absorbing material. <FIG> are perspective views of the impact absorbing rib <NUM> and the impact absorbing rib <NUM>, respectively, each of which serves as an impact absorber according to an embodiment of the present disclosure. <FIG> illustrates the prismatic impact absorbing rib <NUM> provided with a groove <NUM>. <FIG> illustrates the cylindrical impact absorbing rib <NUM> provided with a groove <NUM>. The impact absorbing rib <NUM> is mainly described in the following description. However, the impact absorbing rib <NUM> has like features as the impact absorbing rib <NUM> unless otherwise specified.

Further, the groove <NUM> provided for the impact absorbing rib <NUM> has a specific size. <FIG> is a schematic side view of the impact absorbing rib <NUM> illustrating a size of the groove <NUM>. <FIG> are diagrams each illustrating the structure of the impact absorbing rib <NUM>, according to an embodiment of the present disclosure. <FIG> is a schematic perspective view of the impact absorbing rib <NUM> provided with the groove <NUM>, according to the present embodiment. <FIG> is a schematic cross-sectional view of the impact absorbing rib <NUM> of <FIG> cut along a line B-B illustrated in <FIG>.

The depth hb of the groove <NUM> is preferably in a range of not less than twice the thickness t of the impact absorbing rib <NUM> and equal to or smaller than one fifth of the height ha of the impact absorbing rib <NUM>. In the present embodiment, distances related to the impact absorbing rib <NUM> and the groove <NUM> are set, for example, as follows.

The depth hb of the groove <NUM> is a distance from the top surface of the impact absorbing rib <NUM> to the bottom of the groove <NUM>. A length lg of the groove <NUM> is a distance that connects two points on the outline of the top surface of the impact absorbing rib <NUM> on which the groove <NUM> is formed. A width bb of the groove <NUM> is a distance in a direction intersecting, i.e., orthogonal to, the length lg of the groove <NUM> on the top surface of the impact absorbing rib <NUM>. A width ba of the top surface of the impact absorbing rib <NUM> is a distance obtained by connecting two points on the outline of the top surface in a same direction as the width bb of the groove <NUM>. The width da is a longest distance, such as the length of the diameter in the case of a circle, when it is not determined to be one.

The thickness t of the impact absorbing rib <NUM> is the thickness of the impact absorbing rib <NUM> as a three-dimensional structure having a hollow inside of the impact absorbing rib <NUM>. In addition, in a case in which the thickness t of the impact absorbing rib <NUM> is different depending on positions of the impact absorbing rib <NUM> as the three-dimensional structure, for example, a value in a range from equal to or greater than a minimum value to equal to or smaller than a maximum value is used, and one value may not be defined. At this time, a value in a range from the minimum value to the maximum value may be used only for the thickness of the top surface or the rigidity reinforced portion <NUM> (see <FIG>). In <FIG>, the thickness t of the impact absorbing rib <NUM> is illustrated as an example.

Setting the depth hb of the groove <NUM> to a depth that is approximately twice or greater than the thickness t of the impact absorbing rib <NUM> allows to ensure that the groove <NUM> is precisely formed at the time when the impact absorbing rib <NUM> is fabricated to reliably ensure the degree of rigidity enhancement and exhibit the intended effect of the rigidity enhancement. This is because, when the depth hb of the groove <NUM> is set to be equal to or substantially twice or smaller than the thickness t of the impact absorbing rib <NUM>, the groove <NUM> may not be precisely formed due to, for example, variation when the impact absorbing rib <NUM> is fabricated.

In addition, setting the depth hb of the groove <NUM> to be approximately one fifth or smaller than the height ha of the impact absorbing rib <NUM> allows to prevent a disadvantage caused when the depth of the groove <NUM> is large. <FIG> are diagrams each illustrating a disadvantage that may occur when the groove <NUM> provided for the impact absorbing rib <NUM> has a large depth, according to an embodiment of the present disclosure. More specifically, when the depth hb of the groove <NUM> is larger than one fifth of the height ha of the impact absorbing rib <NUM> (see <FIG>), positions of fulcrums <NUM> of the groove <NUM> are closer to the center of the bottom of the groove <NUM>. Thus, the rigidity reinforced portion <NUM> is unlikely to fall toward the groove <NUM>, as intended as described later. On the other hand, in a case in which the depth hb of the groove <NUM> is extremely large (see <FIG>), the length of the rigidity reinforced portion <NUM> is large. Accordingly, the rigidity reinforced portion <NUM> is structurally likely to fall inward of the groove <NUM>. Thus, the effect of stably promoting compression and crushing of the rigidity reinforced portion <NUM> is lost. In addition, the impact absorbing rib <NUM> absorbs the impact by deforming about half of the height ha of the impact absorbing rib <NUM>. Accordingly, when the depth hb of the groove <NUM> is extremely large (<FIG>), the groove <NUM> contacts the bottom of the impact absorbing rib <NUM> at the time when the impact absorbing rib <NUM> deforms. Thus, the impact absorbing function of the impact absorbing rib <NUM> may be impaired.

Further, as illustrated in <FIG>, the impact absorbing rib <NUM> includes the rigidity reinforced portion <NUM> which are rigidity reinforced portions in an upper portion of the impact absorbing rib <NUM> from the bottom of the groove <NUM> to the top surface of the impact absorbing rib <NUM>. <FIG> is a schematic perspective view of the impact absorbing rib <NUM> in which the rigidity of an upper portion of the impact absorbing rib <NUM> is reinforced, according to the present embodiment. The groove <NUM> is disposed between both sides of the rigidity reinforced portion <NUM>, thus each of the sides of the rigidity reinforced portion <NUM> includes an increased number of side walls. Accordingly, the rigidity reinforced portion <NUM> is unlikely to bend in directions indicated by two arrows in <FIG> due to, for example, the increased number of the side walls. The direction in which the rigidity reinforced portion <NUM> is unlikely to bend differs depending on the shape of the groove <NUM>. However, in <FIG>, the direction is, for example, a circular arc direction along the length direction of the groove <NUM> or a direction along the length direction of the groove <NUM>.

Such a configuration as described above allows the rigidity reinforced portion <NUM> to moderately fall toward the groove <NUM> and the dynamic load of the object to be packaged <NUM> to be applied perpendicularly to the cross section of the outer walls of the lower part of the impact absorbing rib <NUM>, while the upper portion of the impact absorbing rib <NUM> of which the rigidity is high is not deformed in the impact absorbing mechanism. Accordingly, the impact absorbing rib <NUM> can sufficiently absorb the impact energy of the object to be packaged <NUM>, and the impact absorbing properties of the impact absorbing rib <NUM> can be enhanced. Note that, setting the size of the groove <NUM> to the size described above allows the rigidity of the upper portion of the impact absorbing rib <NUM> to be reinforced and prevents an effect gained by an action in which the rigidity reinforced portion <NUM> moderately fall toward the groove <NUM> to be lost when the depth of the groove <NUM> is too large. Such a configuration as described above prevents the loss of the impact energy absorption amount of the impact absorbing rib <NUM> due to the biased load support posture of the impact absorbing rib <NUM> and allows the impact absorbing rib <NUM> to have a structure that reliably exhibits a compression or crush mechanism. Thus, the rigidity of the upper portion of the impact absorbing rib <NUM> around the top surface can be reinforced.

In addition, when the impact absorbing rib <NUM> receives an unbalanced load, the upper portion of the impact absorbing rib <NUM> having high rigidity is unlikely to fall and bend, and the unbalanced load is stably applied to the cross section of the side walls of the impact absorbing rib <NUM> in the vertical direction while the impact absorbing rib <NUM> is not inclined. Thus, a target compression or crushing stress of the impact absorbing rib <NUM> can be exhibited. <FIG> is a schematic cross-sectional view of the impact absorbing rib <NUM> and the object to be packaged <NUM> that is in contact with the impact absorbing rib <NUM> cut along the line B-B illustrated in <FIG>, illustrating how side walls of the impact absorbing rib <NUM> are compressed or crushed, according to the present embodiment. <FIG> illustrates a state before the impact absorbing rib <NUM> and the object to be packaged <NUM> receive an impact in a left side of <FIG> and illustrates a state after the impact absorbing rib <NUM> and the object to be packaged <NUM> have received the impact in a right side of <FIG> illustrates the impact absorbing rib 1p and the object to be packaged <NUM> in a state in which the object to be packaged <NUM> is packaged with a packaging material provided with the impact absorbing rib <NUM> illustrated in <FIG>, such that the object to be packaged <NUM> is in contact with the top surface of the impact absorbing rib <NUM>, in a package cargo. <FIG> illustrates a state in which the impact absorbing rib <NUM> receives an unbalanced load from the object to be packaged <NUM> when the package cargo receives an impact in a right side of <FIG>. When the impact absorbing rib <NUM> that includes the groove <NUM> is disposed in the packaging material, even when the impact absorbing rib <NUM> receives the unbalanced load from the object to be packaged <NUM>, only the compressed and crushed portion <NUM> is generated. Accordingly, the bent and crushed portion 15p as illustrated in <FIG> is not generated. Accordingly, the loss of the impact energy absorption amount of the impact absorbing rib <NUM> can be eliminated, and the impact acceleration applied to the object to be packaged <NUM> can be reduced.

Note that the impact absorbing rib <NUM> includes an upward tapering degree α, for example, <NUM> degrees, for fabrication purpose, as illustrated in <FIG>. Accordingly, there is a concern that a region having high rigidity sinks between the side walls of the impact absorbing rib <NUM> as compression or crushing proceeds from the rigidity reinforced portion <NUM> as starting points, as illustrated, for example, in <FIG> is a schematic perspective view of the impact absorbing rib <NUM> according to the present embodiment. <FIG> is a schematic cross-sectional view of the impact absorbing rib of <FIG> and the object to be packaged <NUM> that is in contact with the impact absorbing rib <NUM> cut along a line C-C illustrated in <FIG>, in a state in which the compressed and crushed portion <NUM> and a bent and buckled portion <NUM> are generated, according to another one of the embodiments of the present disclosure. In <FIG>, a package cargo similar to the package cargo used in <FIG> is used.

<FIG> is a schematic cross-sectional view of the impact absorbing rib <NUM> and the object to be packaged <NUM> that is in contact with the impact absorbing rib <NUM> cut along a line C-C illustrated in <FIG>, in a state in which side walls of the impact absorbing rib <NUM> are compressed or crushed. In <FIG>, a package cargo similar to the package cargo used in <FIG> is used. As illustrated in <FIG>, support portions <NUM> of the groove <NUM> fall into a void area of the opened groove <NUM> such that the posture of the impact absorbing rib <NUM> is naturally corrected and a load can be applied to the side walls of the impact absorbing rib <NUM>. Accordingly, in the impact absorbing mechanism, a dynamic load of the object to be packaged <NUM> is applied vertically to the cross sections of the outer walls of the lower portion of the impact absorbing rib <NUM> while the support portions <NUM> of the groove <NUM> fall moderately toward the groove <NUM> without the upper portion of the impact absorbing rib <NUM> having high rigidity being deformed. Accordingly, the impact absorbing rib <NUM> can be reliably compressed and crushed. Thus, the loss of impact energy absorption of the impact absorbing rib <NUM> can be prevented, and the impact acceleration applied to the object to be packaged <NUM> can be reduced. Embodiments of the present disclosure of the impact absorbing rib <NUM> that includes the above-described groove <NUM> are described below.

In an eighth embodiment, an impact absorbing rib 1a that includes two or more grooves is described. <FIG> is a schematic perspective view of the impact absorbing rib 1a according to the eighth embodiment. The impact absorbing rib 1a includes the two grooves <NUM>. The rigidity of the impact absorbing rib 1a is further reinforced by increasing the number of grooves <NUM>. Further, preferably that the two grooves <NUM> are disposed so as to intersect with each other. More specifically, preferably that the two grooves <NUM> are disposed so as to be orthogonal to each other. Such a configuration as described above allows the rigidity of the upper portion of the impact absorbing rib 1a to be reinforced and allows the impact absorbing rib 1a to perform the rigidity enhancement function reliably as intended. In addition, support portions of the groove <NUM> can fall flexibly in the void area of the opened groove <NUM> in a plurality of directions. Thus, the rigidity enhancement function of the impact absorbing rib 1a can be achieved to the maximum as intended. Such a configuration as described above causes the rigidity reinforced portion <NUM> to be enlarged in the upper part of the impact absorbing rib 1a. Accordingly, the rigidity enhancement function of the impact absorbing rib 1a can be achieved to the maximum as intended.

Each one of the grooves <NUM> is formed, for example, so as to connect two positions on the outline of the top surface of the impact absorbing rib 1a and divide the top surface into two regions. Further, the grooves <NUM> may be formed so as to divide the top surface of the impact absorbing rib 1a substantially equally. As an impact absorbing rib that includes the two or more grooves <NUM>, the impact absorbing rib 1a may include the grooves <NUM> that may be formed, for example, so as to connect three or more positions on the outline of the top surface of the impact absorbing rib 1a and divide the top surface into three or more regions. The shape of the multiple grooves <NUM> are not limited to the shape that intersects each other. For example, the shape of the multiple grooves <NUM> may be a shape such that the multiple grooves <NUM> divide the top surface of the impact absorbing rib 1a into three regions while the groove <NUM> connecting two positions of the four positions on the outline of the top surface and the groove <NUM> connecting the other two positions of the four positions on the outline of the top surface do not intersect with each other.

In a nineth embodiment, modifications of the cross-sectional shape of the groove <NUM> are described. The cross-sectional shape of the groove <NUM> according to the ninth embodiment may be, for example, a U-shape, a C-shape, or a V-shape. The cross-sectional shape of the groove <NUM> is a shape of a recess of the groove <NUM> from the top surface of the impact absorbing rib <NUM> to the bottom of the groove <NUM>, and is, for example, a shape formed by the wall surfaces and the bottom of the groove <NUM>, such as the U-shape or a shape formed by the wall surfaces of the groove <NUM>, such as the V-shape. Further, in the shape formed by the wall surfaces and the bottom of the groove <NUM>, the wall surfaces of the groove <NUM> may be inclined as in the case of the V-shape. <FIG> are diagrams each illustrating cross-sectional shapes of the groove <NUM> of the impact absorbing rib <NUM> according to the nineth embodiment of the present disclosure.

In a tenth embodiment of the present disclosure, the outer shapes of the impact absorbing rib <NUM> and the impact absorbing rib <NUM> are described with reference to <FIG>, respectively. The outer shape of the impact absorbing ribs according to the tenth embodiment as the three-dimensional structure having a hollow interior may be a prismatic shape or a columnar shape. <FIG> is a perspective view of the prismatic impact absorbing rib <NUM> having the prismatic shape. <FIG> is a perspective view of the impact absorbing rib <NUM> having the columnar shape.

The prismatic shape of the impact absorbing rib <NUM> is, for example, a truncated pyramid shape as illustrated in <FIG> or a prism shape. In addition, the shape of the top surface or the bottom surface of the impact absorbing rib <NUM> is a prismatic shape. A part of the prismatic shape may include a deformed portion such as an uneven shape formed by straight lines or curved lines. The columnar shape of the impact absorbing rib <NUM> is, for example, a truncated cone, for example as illustrated in <FIG> or a column. Further, the shape of the top surface or the bottom surface of the impact absorbing rib <NUM> is basically a circular shape or an elliptical shape. A part of the circular shape or the elliptical shape may include a deformed portion formed by straight lines or curved lines.

In an eleventh embodiment, modifications of the groove <NUM> are described. Shapes of the groove <NUM> viewed from above may be formed by an outer shape in which at least one of straight lines or curved lines are continuously connected to each other or any one of the straight lines or the curved lines are continuously connected to each other in a wave-shape. The shape of the outline formed as described above may be an I-shape or a cross shape. In the present embodiment, the shape of the groove <NUM> viewed from above may be a same shape as the top surface of the impact absorbing rib <NUM>. For example, when the groove <NUM> is deformed from the top surface of the impact absorbing rib toward the bottom of the groove <NUM>, the shape of the bottom of the groove <NUM> may be different from the shape of the top surface of the groove <NUM>.

<FIG> are diagrams each illustrating a cross-sectional shape of the groove <NUM> provided for the impact absorbing rib <NUM> according to the eleventh embodiment. <FIG> illustrate shapes of the top surface of the groove <NUM> provided for the impact absorbing rib <NUM> having a truncated quadrangular pyramid shape. <FIG> illustrate the top surface of the groove <NUM> having an I-shape formed by straight lines. <FIG> illustrates the top surface of the groove <NUM> having a cross-shape formed by straight lines. <FIG> illustrates the top surface of the groove <NUM> having a cross-shape formed by straight lines and curved lines. <FIG> illustrates the top surface of the groove <NUM> having a cross-shape formed by straight lines and curved lines. The groove <NUM> having the shapes as described above allows the impact absorbing rib <NUM> to secure the effect of rigidity enhancement function of the impact absorbing rib <NUM>. Note that in the shapes of the groove <NUM> illustrated in <FIG>, when the outer shape of the top surface of the impact absorbing rib <NUM> is a truncated cone, end portions of the groove <NUM> are curved lines. Thus, the shape of the groove <NUM> is an outline continuous in a wave shape formed by connected curved lines.

<FIG> is a diagram illustrating a top view of the groove <NUM> provided for the impact absorbing rib <NUM> in which the groove <NUM> has an outline continuous in a wave shape, illustrating how the rigidity of the outline of the groove <NUM> works against an applied force, according to the present embodiment. As illustrated in <FIG>, when the groove <NUM> has the outline continuous in the wave shape, the rigidity of the impact absorbing rib <NUM> is reinforced with respect to the force received from multiple directions. Accordingly, the rigidity enhancement function of the impact absorbing rib <NUM> can be performed more reliably as intended.

In a twelfth embodiment, the width of the groove <NUM> is described. The dimensions of the impact absorbing rib <NUM> and the groove <NUM> are illustrated in <FIG>. A width bb of the groove <NUM> may be a length that is approximately twice or greater than the thickness t of the impact absorbing rib <NUM>. The impact absorbing rib <NUM> exhibits the effect of rigidity enhancement when the rigidity reinforced portion <NUM> moderately fall into the groove <NUM> (see, for example, <FIG>, and <FIG>). For this reason, desirably the rigidity reinforced portion <NUM> located on both sides along the wall surfaces of the groove <NUM> do not interfere with each other even if the rigidity reinforced portion <NUM> fall toward the groove <NUM>. Accordingly, for the groove <NUM> located between the rigidity reinforced portion <NUM>, the width bb of the groove <NUM> has, preferably, a sufficient distance.

On the other hand, the width bb of the groove <NUM> is preferably set to be smaller than approximately one third of the width ba of the top surface of the impact absorbing rib <NUM>. <FIG> is a schematic side view of the impact absorbing rib <NUM> and the groove <NUM>, illustrating a disadvantage that may occur when the width of the groove <NUM> is too large, according to the present embodiment. Desirably, the impact absorbing rib <NUM> prevents the rigidity reinforced portion <NUM> to be likely to fall toward the groove <NUM>, when each side of the rigidity reinforced portion <NUM> located on both sides along the wall surfaces of the groove <NUM> have a small width. Accordingly, setting the width bb of the groove <NUM> to an appropriate length allows to prevent a disadvantage that impairs the rigidity enhancement effect of the impact absorbing rib <NUM>.

As described above, preferably, the width bb of the groove <NUM> is a length that is approximately twice or greater than the thickness t of the impact absorbing rib <NUM> and a length that is less than approximately one third of the width ba of the top surface of the impact absorbing rib <NUM>.

In a thirteenth embodiment, a molded pulp packaging material provided with an impact absorbing rib according to one of the above embodiments of the present disclosure is described. The packaging material according to the present embodiment includes the impact absorbing rib at least at one position in the packaging material. Such a configuration as described above allows the above-described rigidity enhancement function of the impact absorbing rib to be attained.

In addition, in the packaging material, the impact absorbing rib may be disposed such that a top surface of the impact absorbing rib contacts the object to be packaged. <FIG> is a perspective view of the packaging material <NUM> in which the impact absorbing rib <NUM> is disposed such that the top surface of the impact absorbing rib <NUM> contacts an object to be packaged, according to the present embodiment. In the packaging material <NUM>, the top surface of the impact absorbing rib <NUM> provided with the groove <NUM> contacts the object to be packaged when the object to be packaged is accommodated in the object to be packaged accommodating space <NUM>. Such a configuration as described above allows the object to be packaged to be accommodated in an effective manner such that a load is applied to intended positions of the object to be packaged.

In addition, in the packaging material <NUM>, the impact absorbing rib <NUM> may be disposed such that a surface of the impact absorbing rib <NUM> that includes an opening, i.e., a bottom surface of the impact absorbing rib <NUM>, contacts the object to be packaged. <FIG> is a perspective view of the packaging material <NUM> in which the impact absorbing rib <NUM> is disposed such that the surface of the impact absorbing rib <NUM> that includes the opening contacts the object to be packaged, according to the present embodiment. <FIG> is a perspective view of the packaging material <NUM> viewed from a reverse side from the accommodation space of the packaging material <NUM> in which the object to be packaged is accommodated and illustrates the packaging material <NUM> in a state in which the top surface of the impact absorbing rib <NUM> provided with the groove <NUM> is disposed. Such a configuration as described above allows a surface of the object to be packaged accommodating space <NUM> and a side surface of the object to be packaged to surface contact each other, when the side surface of the object to be packaged is flat. Thus, the object to be packaged, such as a product, can be stably held in the packaging material <NUM>. In addition, the packaging material <NUM> described above may be used, for example, to accommodate an imaging system product.

As described in each of the above embodiments, each of the impact absorbing ribs as examples of the impact absorber according to the embodiments of the present disclosure and each of the packaging materials provided with the corresponding one of the impact absorbing ribs form a structure in which a large impact force is not applied to the object to be packaged. Accordingly, a disadvantage in which the object to be packaged may break can be solved. In addition, the above-described configuration according to the embodiments allows the quality of the packaging material as a packaging material for protecting an object to be packaged to be significantly enhanced, which leads to delivery of a product to a customer without breakage. Further, solving the disadvantages that are inherent in the comparative molded pulp impact absorbing materials allows to promote the use of materials having desirable resource recovery and recycling properties. Thus, the degree of contribution of using the above-described packaging material toward the realization of a circular society and the solving of plastic environmental disadvantages can be enhanced.

Results of a test using the impact absorbing ribs according to the above embodiments and the control sample of the present disclosure are described in the following description. Test Method In the test, the spectral response acceleration of the object to be packaged was measured using the packaging material that includes the impact absorbing rib according to the control sample and the packaging material that includes the impact absorbing rib according to one of the above-described embodiments of the present disclosure. <FIG> are diagrams each illustrating the impact absorbing rib 1p and the impact absorbing rib <NUM> used in the test, respectively. <FIG> is a diagram illustrating the impact absorbing rib 1p according to the control sample. <FIG> is a diagram illustrating the impact absorbing rib <NUM> according to the embodiment of the present disclosure.

As the control sample, the impact absorbing rib 1p that has a basic structure of a truncated quadrangular pyramid shape known in the art was used. As the impact absorbing rib according to the embodiment, the impact absorbing rib <NUM> that has a truncated quadrangular pyramid shape, provided with the groove <NUM>, is used. A drop test was conducted under following conditions to measure the impact response acceleration of the object to be packaged.

Impact absorbing material: corrugated cardboard wastepaper.

Thickness t of molded pulp impact absorbing material = <NUM>.

<FIG> is a table illustrating test results of the drop test using impact absorbing rib 1p and the impact absorbing rib <NUM>. Five tests from test number N1 to N5 were conducted to measure the impact response accelerations (G's) of an external component of a product to calculate the average accelerations (G's) and the standard deviation of measured values (1δ). The impact response accelerations of the impact absorbing rib 1p according to the control sample were <NUM>'s as the average accelerations. In comparison, the impact response accelerations of the impact absorbing rib <NUM> according to the embodiment were <NUM>'s. Further, the standard deviation of the measured values that indicates variations was reduced by half to <NUM> of the impact absorbing rib <NUM> according to the embodiment as compared with <NUM> of the impact absorbing rib 1p according to the control sample. As described above, relatively excellent results were obtained.

Other embodiments and each of the above-described embodiments are described with reference to the packaging materials made of molded pulp and the impact absorbing ribs made of molded pulp. However, the packaging materials and the impact absorbing ribs are not limited to molded pulp packaging materials and the molded pulp impact absorbing ribs. For example, another material such as a non-resin plastic impact absorbing material may be used for the impact absorbing rib and the packaging material.

Claim 1:
An impact absorber (<NUM>, 1a, 1x, <NUM>) comprising a three-dimensional structure, the three-dimensional structure including:
a closed top surface located at the upper portion of the impact absorber disposed at a position to contact on an object to be packaged;
an open bottom located at the lower portion of the impact absorber;
a hollow inside; and
a recess (<NUM>, 11x, <NUM>) within an outline of the top surface, characterised in that
the upper portion and lower portion are configured such that upon the application of an impact to the impact absorber, the lower portion of the impact absorber deforms to generate a compressed and crushed portion (<NUM>) and a buckled portion (<NUM>) such that the upper portion sinks to a lower position while maintaining a constant shape.