WO2020246163A1

WO2020246163A1 - Corrugated cardboard material and corrugated cardboard box using same

Info

Publication number: WO2020246163A1
Application number: PCT/JP2020/017263
Authority: WO
Inventors: 祥平眞田; 悠生川浪; 壮佐藤; 豪盤指; 貴迪山口; 隼介塩田; 優作高杉; 良樹小関
Original assignee: 王子ホールディングス株式会社
Priority date: 2019-06-05
Filing date: 2020-04-21
Publication date: 2020-12-10
Also published as: MY192401A; AU2023200158A1; AU2020287947B2; AU2020287947A1; AU2023200160A1; AU2023200159A1

Abstract

A corrugated cardboard material (1) is designed such that a rectangle sheet (2) in a sequential double-sided corrugated cardboard is folded back in a second direction MD at each fold F linearly extending along a first direction CD and stacked in a third direction TD. In the corrugated cardboard material (1), a liner constituting the double-sided corrugated cardboard has a basis weight of 110 [g/m²] or more and 290 [g/m²] or less. The liner has a pulp fiber length of 0.55 [mm] or more and 1.60 [mm] or less. A fiber orientation ratio representing the ratio of the orientation of pulp fibers of the liner in the second direction MD to the orientation thereof in the first direction CD is 1.0 or more and 2.0 or less. A fiber length ratio representing the ratio of a pulp fiber length of a liner base paper to a pulp fiber length of a corrugating medium constituting the double-sided corrugated cardboard is 0.65 or more and 1.90 or less.

Description

Cardboard material and cardboard boxes using it

The present invention relates to a bellows-folded cardboard material and a cardboard box using the same.

Corrugated cardboard material with bellows fold (also called "fan fold") is known as a material for box making. The corrugated cardboard material is provided with creases between continuous rectangular sheets, and the sheets are alternately folded back at the folds. In such a bellows-folded cardboard material, continuous sheets are stacked one above the other and folded into a rectangular parallelepiped packaging.

The above cardboard materials are box-making systems (“automatic packaging system”, “three-side variable system”, “three-side automatic packaging”, and “on-demand packaging” that manufacture boxes of the optimum size according to the size of the object to be packaged. It is also used as a packaging material. In this box-making system, various steps illustrated below are carried out (see Patent Document 1 below).
・ Feed process: Process of feeding out bellows-folded cardboard material ・ Cutting process: Process of cutting out flat cardboard material fed in the feed process ・ Folding process: Process of assembling a box from the cardboard material cut out in the cutting process ・ Printing process : The process of printing on a flat or assembled cardboard material ・ Packing process: The process of storing the contents in the assembled box

Special Table 2013-513869

However, depending on the properties used for the bellows-folded cardboard material, there is a risk of damaging the folds, and when the bellows-folded cardboard material is used as the material for the box-making system, the state of the manufactured box is poor. There is a risk of becoming.
This case was devised in view of the above problems, and the first purpose is to suppress the damage of folds, and the second purpose is to manufacture a box in good condition. Not limited to this purpose, it is also possible to exert actions and effects derived from each configuration shown in the "mode for carrying out the invention" described later, which cannot be obtained by the conventional technique. It can be positioned as another purpose.

The corrugated cardboard material disclosed here is a second corrugated cardboard material orthogonal to the first direction on a plane along the fold at each of the folds in which a rectangular sheet extends linearly along the first direction in continuous cardboard. A bellows-folded corrugated cardboard material that is folded back in a direction and the sheets are stacked along a third direction orthogonal to both the first direction and the second direction.
The corrugated cardboard material has a predetermined structure with respect to the properties used for the corrugated cardboard material.
The predetermined configuration includes at least one of the configurations a to f shown below.
Of the configurations a to f, the configurations a to e are pretreated for 24 hours or more under temperature and humidity conditions of a temperature of 23 [° C.] and a humidity of 50 [%] in accordance with JIS Z0203: 2000 regarding the properties of the sheet. It is a predetermined configuration which is a parameter of the sheet measured in the applied normal state.

Configuration a includes the

following configurations

1 and 2.
Configuration 1 includes that the thickness dimension measured in accordance with the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less.
Configuration 2 includes that the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less.

Configuration b includes the above configuration 2 and the following configuration 3.
The configuration 3 includes a step-by-step rate of 1.2 [times] or more and 1.7 [times] or less.

In configuration c, the cores intersect and are adjacent to a virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The ratio of the difference between the two acute angles formed by the auxiliary line and the auxiliary line divided by the sum of the two acute angles is 0.30 or less.

Configuration d includes that the burst strength measured in accordance with JIS P8131: 2009 is 500 [kPa] or more.
The configuration d'includes that, in a single flute double-sided corrugated cardboard, the burst strength at a portion including a crease measured according to JIS P8131: 2009 is 500 [kPa] or more.
In the configuration d ″, the burst strength of the double-sided corrugated cardboard of the double flute, which is measured in accordance with JIS P8131: 2009 and does not include creases, is 500 [kPa] or more, and conforms to JIS P8131: 2009. It is included that the burst strength of the portion including the crease measured in the above is 520 [kPa] or more.

The configuration e includes that the average value of the adhesive force measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more.

In the configuration f, the basis weight of the liner constituting the double-sided cardboard is 110 [g / m ² ] or more and 290 [g / m ² ] or less, and the pulp fiber length of the liner is 0.55 [mm]. ] Or more and 1.60 [mm] or less, and the fiber orientation ratio, which is the ratio of the orientation of the pulp fibers in the first direction to the orientation in the second direction in the liner, is 1.0 or more and 2 It is included that the fiber length ratio, which is 0.0 or less and is the ratio of the pulp fiber length of the liner to the pulp fiber length of the core constituting the double-sided cardboard, is 0.65 or more and 1.90 or less. Is done.

According to the configurations a to e of the present case, a box in good condition can be manufactured.
According to the configuration f of the present case, damage to the fold can be suppressed.

It is a perspective view which shows the corrugated cardboard material of a bellows fold. It is a schematic diagram which shows an example of the step | step in the sheet used for the corrugated cardboard material of bellows folding. It is a schematic diagram which shows the evaluation box for evaluating the easiness of tearing from the top view. It is a schematic diagram which shows the evaluation box for evaluation of easiness of tearing from the side view.

Hereinafter, a cardboard material and a cardboard box as embodiments will be described.
The corrugated cardboard material of the present embodiment is a bellows-folded box-making material in which a rectangular sheet is folded in continuous corrugated cardboard. As this corrugated cardboard material, double-sided corrugated cardboard having liners on both sides with respect to the core is used.
The above-mentioned double-sided cardboard includes single-flute cardboard composed of three base papers (materials) corresponding to one core and two liners, as well as so-called "double-sided cardboard" and "double-sided cardboard". Also included are multi-flute corrugated cardboard composed of two or more cores and five or more base papers corresponding to each of the two liners and one or more middle liners.

When the cardboard material is made, it becomes a cardboard box. Specifically, the corrugated cardboard material used as the box-making material of the box-making system has a feed process in which the sheets are sequentially fed, a cutting process in which the delivered sheets are cut out in a box development pattern, and folding into a box shape. It is made into a cardboard box through various processes such as a folding process in which it is erected. The box-making system for assembling the cardboard box is not particularly limited, but for example, "CMC's Carton Wrap XL" and "CMC's carton wrap 1000", which are fully automatic systems (fully automatic machines) for automatic packaging systems. , "CVP-500 made by Neopost", "TXP-600 made by OS Machinery", "EM7 made by Pack Size" of semi-automatic system (semi-automatic machine), "Compack made by Panotec", "HOMAG" PAQTEC C-200 manufactured by HOMAG and PAQTEC C-250 manufactured by HOMAG can be used.

In the present embodiment, it is assumed that the corrugated cardboard material is placed on a horizontal plane by giving an example in which the following directions I and II correspond as shown in Table 1 below.
-Direction I: Direction in the corrugated cardboard placed on the horizontal plane-Direction II: Direction in the semi-finished product in the middle of manufacturing the cardboard material

The vertical direction (first direction, indicated by "CD" in the figure) and the horizontal direction (second direction, indicated by "MD" in the figure) are horizontal directions and along the sheet (crease). The direction in which the plane extends. These vertical and horizontal directions are orthogonal to each other. The height direction (third direction, indicated by "TD" in the figure) is a direction along the vertical direction and is orthogonal to both the vertical direction and the horizontal direction. This height direction corresponds to the direction in which the sheets are overlapped.

The MD (Machine Direction) direction is also referred to as a "flow direction", and is a direction in which the corrugated cardboard material manufacturing process progresses from upstream to downstream. The CD (Cross Direction) direction is a direction orthogonal to the MD direction in a plane along the MD direction. The TD (Transverse Direction) direction is a direction orthogonal to both the MD direction and the CD direction.
In addition, unless otherwise specified, the expression "numerical value X to numerical value Y" in this embodiment means a range of numerical value X or more and numerical value Y or less.

[I. One Embodiment]
In one embodiment below, the configuration of the corrugated cardboard material will be described in items [1] and [2]. Item [1] describes a structure in which the corrugated cardboard material is folded (hereinafter referred to as “folded structure”). Item [2] describes parameters related to the properties of the sheet (corrugated cardboard sheet) used for the corrugated cardboard material.
Then, the actions and effects of the configurations of items [1] and [2] will be described in item [3].

[1. Folding structure]
As shown in FIG. 1, the corrugated cardboard material 1 is a box-making material having a rectangular parallelepiped shape.
In the corrugated cardboard material 1, the continuous rectangular sheet 2 (partially marked in FIG. 1) is folded back at the fold F (only partly coded in FIG. 1), and the folded sheet 2 is folded. They are stacked in the height direction.
In the corrugated cardboard material 1 folded in this way, a plurality of folds F extend linearly along the vertical direction on a pair of side surfaces along both the vertical direction and the height direction.

Here, the folding structure of the corrugated cardboard material 1 will be described by focusing on three consecutive sheets 2 (indicated by a two-dot chain line in FIG. 1).
1st sheet 21: Sheet 2 continuous on one side of the 2nd sheet 22
Second sheet 22: Sheet 2 continuous with both the first sheet 21 and the third sheet 23
-Third sheet 23: Sheet 2 continuous with the other side of the second sheet 22

The first fold F1 is provided between the first sheet 21 and the second sheet 22, and the

sheets

21 and 22 are continuous via the first fold F1. A second fold F2 is provided between the second sheet 22 and the third sheet 23, and the

sheets

22 and 23 are continuous via the second fold F2.
The first fold F1 is a fold F in which the second sheet 22 is folded back toward one side in the lateral direction (to the right in FIG. 1) with respect to the first sheet 21, and the other side in the corrugated cardboard material 1 (right side in FIG. 1). It is arranged on the left side in FIG. The second fold F2 is a fold F in which the third sheet 23 is folded back toward the other side in the lateral direction (left in FIG. 1) with respect to the second sheet 22, and the second fold F2 is one in the lateral direction (one in the corrugated cardboard material 1). It is arranged on the right side in FIG.

In the first sheet 21, the corrugated cardboard step 10 (in FIG. 1, only the front edge is marked) extends to the _first edge E ₁ extending in the lateral direction (the direction intersecting the fold F). Waves) are exposed. Similarly, on the second sheet 22, the cardboard is provided on the second edge E ₂ extending in the lateral direction (the direction intersecting the crease F) (in FIG. 1, only the front edge is marked). The step 10 is exposed.
In the sheet pair 20 composed of the first sheet 21 and the second sheet 22, the first end edge E ₁ and the second end edge E ₂ are arranged adjacent to each other in the height direction.

According to the corrugated cardboard material 1 having the above-mentioned folding structure, even a material that is difficult to be wound in a roll shape can be folded into a rectangular parallelepiped shape. That is, the corrugated cardboard sheet 2 having a higher strength than the material that can be wound in a roll shape can be made into a compact packaging. The corrugated cardboard material 1 in which the sheet 2 whose strength is ensured is folded in this way is suitable for use as a packaging material for a box-making system for manufacturing a box in which strength is required.

In addition, the fold F is provided along the corrugated cardboard step 10. In other words, the corrugated cardboard material 1 having a step 10 perpendicular to the MD direction is manufactured.
The corrugated cardboard material 1 is preferably wrapped (wrapped) with a packaging film in order to prevent stains and collapse of the load.

[2. Parameters]
Hereinafter, the parameters of the corrugated cardboard material 1 will be described.
First, basic parameters such as the size and the number of stages of the corrugated cardboard material 1 will be described. After that, the parameters related to the sheet 2 of the corrugated cardboard material 1 will be described in detail.

[2-1. Basic parameters]
The size of the corrugated cardboard material 1 is determined from the following dimensions L1 to L3.
-Vertical dimension L1: Vertical dimension (first dimension)
-Horizontal dimension L2: Horizontal dimension (second dimension)
-Height dimension L3: Dimension in the height direction (third dimension)
The smaller the above dimensions L1 to L3, the greater the restrictions on the size and shape of the box to be manufactured, and the larger the size, the lower the workability such as transportation and delivery. From these viewpoints, the dimensions L1 to L3 are preferably in the range shown in Table 2 below.

In addition, if the number of folds F in the corrugated cardboard material 1 is N [sheets], the number of sheets 2 is N + 1 [sheets]. In this case, the N + 1 [stage] sheets 2 are overlapped on the cardboard material 1.
For example, as the number of stages of the corrugated cardboard material 1, for example, various stages of 10 to 1000 [stages] can be mentioned. For the corrugated cardboard material to which the parameters related to folding, which will be described in detail later, are measured, it is preferable to measure the parameters at each of all the stages for the measurement target having less than a predetermined number of stages (for example, 100 [stages]). On the other hand, for a measurement target having a predetermined number of stages (for example, 100 [stages]) or more, the parameters may be measured partially (for example, a portion divided into parts or a set area).

An arbitrary basis weight can be set for the sheet 2 used for the corrugated cardboard material 1. The range of the basis weight adopted for the sheet 2 includes a range of 50 to 1500 [g / m ² ], preferably a range of 100 to 1000 [g / m ² ], and more preferably 200 to 200. The range of 800 [g / m ² ] is mentioned, and more preferably the range of 200 to 600 [g / m ² ] is mentioned.
The weight of the corrugated cardboard material 1 is calculated by multiplying the above basis weight by the vertical dimension L1 and the horizontal dimension L2 and the number of steps N + 1 of the sheet 2.

[2-2. Parameters related to properties]
The present embodiment includes a configuration relating to the properties of the corrugated cardboard material 1 from the viewpoint of enabling a good box to be manufactured when used as a material for a box making system. Specifically, it has a predetermined configuration regarding the properties of the corrugated cardboard material 1 based on at least one of the viewpoints I to VI listed below.
・ Viewpoint I: Ensuring box-making property ・ Viewpoint II: Suppressing breakage of bent parts when assembling into a box ・ Viewpoint III: Ensuring suitability when printing is performed ・ Viewpoint IV: Suppressing tearing (damage) of the assembled box ・ Viewpoint V: Suppressing the peeling of the liner ・ Viewpoint VI: Suppressing damage to the fold F

The above viewpoints I to VI are viewpoints for solving the following problems I to VI in which common ordinals I to VI are described.
・ Problem I: Insufficient box-making property ・ Problem II: The bent part is easily broken when assembled into a box ・ Problem III: Insufficient suitability when printing is applied・ Problem IV: Easy to tear the assembled box ・ Problem V: Easy to peel off the liner ・ Problem VI: Easy to damage the crease F

The predetermined configurations corresponding to the above viewpoints I to VI and the tasks I to VI include at least one of the configurations a to f shown below.
-Structure a: The following

configurations

1 and 2
＞ Configuration 1: Thickness dimension is within a predetermined dimensional range ＞ Configuration 2: Planar compressive strength is within a predetermined compressive strength range ・ Configuration b: The following configurations 2 and 3
> Configuration 2: Configuration 2 above
> Configuration 3: The step-by-step ratio is within a predetermined magnification range ・ Configuration c: The angle ratio is within a predetermined ratio range ・ Configuration d: The burst strength is within a predetermined burst strength range ・ Configuration d ′ : The bursting strength of the portion including the crease F in the corrugated cardboard material 1 made of double-sided corrugated cardboard of a single flute is within a predetermined bursting strength range. Satisfying configurations 4 and 5 of ＞ Configuration 4: The burst strength of the portion not including the crease F is within the predetermined burst strength range ＞ Configuration 5: The burst strength of the portion including the fold F is predetermined Burst strength range ・ Configuration e: Adhesive strength is within a predetermined force range ・ Configuration f: The following configurations 6 to 9
＞ Composition 6: The liner basis weight is in the predetermined basis weight range ＞ Composition 7: The liner pulp fiber length is in the predetermined fiber length range ＞ Composition 8: The liner fiber orientation ratio is in the predetermined orientation ratio range > Composition 9: The fiber length ratio is within the predetermined fiber length ratio range.

<Structure a>
As described above, the configuration a includes "configuration 1 in which the thickness dimension is in a predetermined dimensional range" and "configuration 2 in which the planar compressive strength is in a predetermined compressive strength range".
The "thickness dimension" of the configuration a is a parameter representing the thickness of the sheet 2 per sheet. The "planar compressive strength" of the configuration a is the strength when the sheet 2 is compressed in the thickness direction (height direction, TD direction), and is a parameter corresponding to the difficulty of crushing the sheet of the corrugated cardboard material 1.

The inventors of the present application have found that if the thickness dimension of the sheet 2 is within a predetermined dimensional range and the planar compressive strength is within a predetermined compressive strength range, the above-mentioned problems I and II tend to be suppressed. Got Conversely, it was found that the sheet 2 having a thickness dimension and a planar compressive strength outside the range of the configuration a tends to cause problems I and II.
That is, the sheet 2 is provided with the configuration a based on the above-mentioned viewpoints I and II.

If the thickness dimension exceeds the predetermined dimension range, it is presumed that when the sheet 2 is bent by the ruled line for box making, the

liners

2a and 2b are not fully stretched and are broken, which causes the problem II. On the other hand, if the thickness dimension is less than the predetermined dimension range, it is presumed that the strength of the sheet 2 is insufficient and the sheet 2 is bent at a place other than the ruled line for box making, which causes the problem I. Even when the plane compressive strength is below the predetermined compressive strength range, it is presumed that the strength of the sheet 2 is insufficient and it is bent at a place other than the ruled line for box making, which causes problem I. To.
Further, if the planar compressive strength exceeds a predetermined compressive strength range, it is presumed that the ruled lines for box making are difficult to form, which causes the problem I.

The "predetermined dimensional range" of the configuration a is 2.0 [mm] or more and 9.6 [mm] or less, and 3.0 [mm] or more and 8.0 [mm] or less. It is preferable that it is 4.0 [mm] or more and 7.0 [mm] or less.
Further, the "predetermined compressive strength range" of the configuration a is preferably 50 [kPa] or more and 250 [kPa] or less, and 80 [kPa] or more and 220 [kPa] or less. It is more preferable that it is 110 [kPa] or more and 190 [kPa] or less.

<Structure b>
The configuration b includes the same "configuration 2 in which the planar compressive strength is in a predetermined compressive strength range" and the above-mentioned "configuration 3 in which the step ratio is in a predetermined magnification range" similar to the configuration a.
The "step ratio" of the configuration b is a parameter representing the magnification of the length dimension in the MD direction (horizontal direction) with respect to the liner of the core.

The inventors of the present application have found that if the planar compressive strength of the sheet 2 is within a predetermined compressive strength range and the step-by-step ratio is within a predetermined magnification range, the above-mentioned problem I tends to be suppressed. Obtained. Conversely, it was found that the sheet 2 having the plane compression strength and the step-by-step ratio outside the range of the configuration b tends to cause the problem I.
That is, the sheet 2 is provided with the configuration b based on the above-mentioned viewpoint I.

If the plane compressive strength is less than the predetermined compressive strength range, it is presumed that the problem I is caused by the insufficient strength of the sheet 2 as described above. On the other hand, if the planar compressive strength exceeds a predetermined compressive strength range, it is presumed that the ruled lines for box making are difficult to form, which causes problem I.
Similarly, if the step-by-step ratio is less than the above-mentioned predetermined magnification, it is presumed that the problem I is caused by the insufficient strength of the sheet 2. On the other hand, if the step-by-step ratio exceeds the above-mentioned predetermined magnification, it is presumed that the ruled line for box making is difficult to be formed, which causes the problem I.

The "predetermined compressive strength range" of the configuration b is 50 [kPa] or more and 250 [kPa] or less, and 80 [kPa] or more, similarly to the "predetermined compressive strength range" of the configuration a. It is preferably 220 [kPa] or less, and more preferably 110 [kPa] or more and 190 [kPa] or less.
The "predetermined magnification range" of configuration b is 1.2 [times] or more and 1.7 [times] or less, and 1.35 [times] or more and 1.6 [times] or less. It is preferable, and it is more preferable that it is 1.45 [times] or more and 1.55 [times] or less.

The magnification range of the step-by-step rate referred to here can be applied not only when the sheet 2 is a single flute but also when the sheet 2 is a double flute. Specifically, the stepping rate of any of the cores of the double flute is 1.2 [times] or more and 1.7 [times] or less, and 1.35 [times] or more and 1 It is preferably 6.6 [times] or less, and more preferably 1.45 [times] or more and 1.55 [times] or less. The step-by-step rate of the double flute referred to here is a step-by-step rate calculated for each stage (the stage corresponding to each flute of one and the other in the double flute).

<Structure c>
As described above, the configuration c includes "a configuration in which the angle ratio is within a predetermined ratio range".
The “angle ratio” of the configuration c is a parameter corresponding to the degree of inclination of the step 10 in the sheet 2 of the corrugated cardboard material 1.
Hereinafter, the angle ratio will be described with reference to FIG. 2, which shows an enlarged main part of the sheet 2. FIG. 2 illustrates a state in which the step 10 of the sheet 2 is slightly tilted.

The sheet 2 has a structure in which the

liners

2a and 2b on the front and back surfaces and the core 2c are adhered to each other. The core 2c constitutes the step 10, and forms a corrugated structure between the

liners

2a and 2b.
If the core 2c has an ideal shape, the cross section (that is, the step 10) along the lateral direction and the height direction has a sinusoidal shape. On the other hand, in the actual sheet 2, the step 10 formed by the core 2c may be tilted with respect to the ideal shape. The angle ratio expresses the degree of such inclination.

This angle ratio is a ratio calculated based on the angles θ1 and θ2 (intersection angles) at which the core 2c and the auxiliary line L intersect.
The auxiliary line L is a virtual line that is parallel to the

liners

2a and 2b (that is, the lateral direction <MD direction>) and passes through the center of the

liners

2a and 2b (that is, the center of the height direction <TD direction>). Is set as.
The angles θ1 and θ2 are acute angles among the intersection angles at the two adjacent points P1 and P2 at the points where the core 2c intersects the auxiliary line L.

The angle ratio is the ratio obtained by dividing the absolute value of the difference between the two angles θ1 and θ2 by the sum of the two angles θ1 and θ2. This angle ratio is represented by the following formula c.
Angle ratio = | θ1-θ2 | / (θ1 + θ2) ... Equation c
The angle ratio defined in this way is 0 (zero) in the case of the ideal step 10, and becomes a large value as the step 10 is deviated.

The inventors of the present application have found that if the angle ratio of the sheet 2 is within a predetermined ratio range, the above-mentioned problem III tends to be suppressed. Conversely, it was found that the sheet 2 having an angle ratio outside the range of the configuration c tends to cause the problem III.
That is, the sheet 2 is provided with the configuration c based on the above-mentioned viewpoint III.
If the angle ratio exceeds a predetermined ratio range, the heights of the steps 10 on the sheet 2 tend to be uneven, which is presumed to lead to Problem III.
The “predetermined ratio range” of the configuration c is 0.30 or less, preferably 0.15 or less, and more preferably 0.05 or less.

<Structure d>
As described above, the configuration d includes "a configuration in which the burst strength is within a predetermined burst strength range".
The “burst strength” of the configuration d is a parameter corresponding to the load capacity of the sheet 2 in the corrugated cardboard material 1.
The inventors of the present application have found that if the burst strength of the sheet 2 is within a predetermined burst strength range, the above-mentioned problem IV tends to be suppressed. Conversely, it was found that the sheet 2 having a burst strength outside the range of the configuration d tends to cause the problem IV.

That is, the sheet 2 is provided with the configuration d based on the above-mentioned viewpoint IV.
If the burst strength is less than the predetermined burst strength range, it is presumed that the problem IV is caused by the insufficient load capacity of the sheet 2.
The "predetermined burst strength range" of the configuration d is 500 [kPa] or more, preferably 1000 [kPa] or more, and more preferably 2000 [kPa] or more.

<Structure d'>
As described above, the configuration d'provides a corrugated cardboard material 1 made of double-sided corrugated cardboard with a single flute, "a configuration in which the burst strength at a portion including the fold F is within a predetermined burst strength range".
The “burst strength” of the configuration d ′ is the same as the “burst strength” described above in the configuration d, except that it is the burst strength of the portion including the crease F.
The inventors of the present application have stated that the above-mentioned problem IV tends to be suppressed if the burst strength of the portion of the sheet 2 of the single flute cardboard material 1 including the crease F is within a predetermined burst strength range. I got the knowledge. Conversely, it was found that the sheet 2 having the burst strength at the portion including the fold F outside the range of the configuration d'tends to cause the problem IV.

That is, the sheet 2 is provided with a configuration d'based on the above-mentioned viewpoint IV.
If the burst strength of the single flute at the portion including the fold F is less than the predetermined burst strength range, it is presumed that the problem IV is caused by the insufficient load capacity of the sheet 2.
The "predetermined burst strength range" of the configuration d'is 500 [kPa] or more, preferably 650 [kPa] or more, and more preferably 1500 [kPa] or more.

<Structure d ″>
As described above, the configuration d ″ is described in the corrugated cardboard material 1 made of double-sided corrugated cardboard with double flutes, “a configuration 4 in which the burst strength at a portion not including the crease F is within a predetermined burst strength range” and “fold F”. 5 ”is provided, in which the burst strength of the portion including the above is within a predetermined burst strength range.
The “burst strength” of the configuration d ″ is the burst strength of the portion not including the fold F and the portion including the crease F, respectively, except that the “burst strength” described in the configurations d and d ′ is described above. It is the same as "strength".
The inventors of the present application have determined that the burst strength of the sheet 2 of the double flute cardboard material 1 that does not include the fold F is within the predetermined burst strength range and the burst strength of the portion that includes the crease F is predetermined. It was found that the above-mentioned problem IV tends to be suppressed within the burst strength range of. Conversely, it was found that the sheet 2 having the burst strength at the portion including the fold F outside the range of the configuration d ″ tends to cause the problem IV.

That is, the sheet 2 is provided with a configuration d ″ based on the above-mentioned viewpoint IV.
In the double flute sheet 2, the burst strength of the portion not including the crease F is below the predetermined burst strength range, or the burst strength of the portion including the fold F is below the predetermined burst strength range. If so, it is presumed that the problem IV is caused by the insufficient load capacity of the sheet 2.
The "predetermined burst strength range" of the portion of the configuration d ″ that does not include the fold F is 500 [kPa] or more, preferably 700 [kPa] or more, and 1000 [kPa] or more. Is more preferable. The "predetermined burst strength range" of the portion including the fold F is 520 [kPa] or more, preferably 800 [kPa] or more, and more preferably 1500 [kPa] or more.

Further, the inventors of the present application tend to suppress the above-mentioned problem IV as the burst strength of the portion not including the crease F and the burst strength of the portion including the crease F are increased, while the crease We also found that damage is likely to occur at point F. That is, if the burst strength exceeds a predetermined upper limit, it is presumed that damage is likely to occur at the crease F. Here, the damage includes cracking, tearing, tearing, etc. of the liner at the crease. The crease portion is an area including the periphery of the fold.
The predetermined upper limit of the burst strength of the portion including the fold F and the portion including the crease F is 2500 [kPa], and 2250 from the viewpoint of obtaining a bellows-folded corrugated cardboard material in which the crease F is less likely to be cracked. It is preferably [kPa], and more preferably 2000 [kPa].

<Structure e>
As described above, the configuration e includes "a configuration in which the adhesive force is within a predetermined force range".
The "adhesive force" of the configuration e is a parameter corresponding to the strength of bonding the core 2c of the sheet 2 and the

liners

2a and 2b.
The "adhesive force" referred to here is the adhesive force between the core 2c and the front liner 2a (adhesive force on the glue machine side) and the adhesive force between the core 2c and the back liner 2b (adhesion on the single facer side). It means the average value with (force).

The inventors of the present application have found that the above-mentioned problem V tends to be suppressed if the adhesive force of the sheet 2 is within a predetermined force range. Conversely, it was found that the sheet 2 having an adhesive strength outside the range of the configuration e tends to cause the problem V.
That is, the sheet 2 is provided with the configuration e based on the above-mentioned viewpoint V.
If the adhesive force is less than the predetermined force range, it is presumed that the

liners

2a and 2b are likely to be peeled off from the core 2c when the cardboard material 1 is manufactured in the box, which causes the problem V.
The "predetermined force range" of the configuration e is 140 [N] or more, preferably 190 [N] or more, and more preferably 220 [N] or more.

<Structure f>
Configuration f has configurations 6 to 9 as described above with respect to the liner constituting the double-sided corrugated cardboard of the corrugated cardboard material 1. The liner for which each parameter is specified in the configurations 6 to 9 includes a front liner and a back liner, and can be said to be a liner constituting the sheet 2 used for the corrugated cardboard material 1.

The “basis weight” of the configuration 6 is a parameter representing the weight [g] per liner area 1 [m ² ].
The “pulp fiber length” of configuration 7 is the length of the pulp fibers constituting the liner. Hereinafter, the pulp fibers constituting the liner will be referred to as "liner fibers", and the length of the liner fibers will be referred to as "liner fiber length".
The “fiber orientation ratio” of the configuration 8 is the ratio of the horizontal orientation to the vertical orientation of the liner fibers (MD / CD).

The “fiber length ratio” of the configuration 9 is the ratio of the liner fiber length to the pulp fiber length of the core constituting the double-sided corrugated cardboard of the corrugated cardboard material 1 (liner / core). Hereinafter, the pulp fiber of the core is referred to as "core fiber", and the length of the core fiber is referred to as "core fiber length".
With respect to configurations 7 and 9, the liner fiber length is the absolute length, whereas the fiber length ratio is the relative length of the liner fiber length to the core fiber length.

The inventors of the present application have obtained the finding that the above-mentioned problem VI tends to be effectively suppressed according to the corrugated cardboard material 1 having all of the configurations 6 to 9. Conversely, it was found that the corrugated cardboard material 1 which does not have any one of the configurations 6 to 9 tends to cause a problem VI.

That is, based on the above-mentioned viewpoint VI, the corrugated cardboard material 1 is provided with the configurations f of the configurations 6 to 9.
--Composition 6--
The smaller the basis weight of the liner with respect to the configuration 6, the lower the strength of the liner tends to be. From this tendency, it is presumed that if the basis weight of the liner is smaller than the predetermined lower limit basis weight, the problem VI is caused by the lack of the overall strength of the liner.

On the other hand, as for the basis weight of the liner with respect to the configuration 6, not only the strength of the liner tends to increase as the weight increases, but also the thickness of the liner (also referred to as “bulk” or “paper thickness”) tends to increase. From this tendency, it is presumed that if the basis weight of the liner is larger than the predetermined upper limit basis weight, the stress due to the folding back of the fold F in the corrugated cardboard material 1 tends to be concentrated on the liner, which causes a problem VI.

Therefore, the “predetermined basis weight range” of the configuration 6 is set to be equal to or more than a predetermined lower limit basis weight and not more than a predetermined upper limit basis weight. The predetermined lower limit basis weight is 110 [g / m ² ], preferably 115 [g / m ² ], and more preferably 140 [g / m ² ]. The predetermined upper limit basis weight is 290 [g / m ² ] or less, preferably 240 [g / m ² ], and more preferably 180 [g / m ² ].

--Composition 7--
The shorter the liner fiber length with respect to the configuration 7, the lower the degree of entanglement between the liner fibers, and the lower the overall strength of the liner tends to be. From this tendency, it is presumed that if the liner fiber length is smaller than the predetermined lower limit fiber length, the strength of the liner is insufficient, which causes a problem VI.

On the other hand, the longer the liner fiber length with respect to the configuration 7, the higher the overall strength of the liner, but the more uneven the surface of the liner tends to be. From this tendency, if the liner fiber length is larger than the predetermined upper limit fiber length, large irregularities are formed on the surface of the liner, and the specifications and quality required for the corrugated cardboard material 1 cannot be satisfied (suitable for the corrugated cardboard material 1). There is a risk.
Further, the longer the liner fiber length with respect to the configuration 7, the higher the degree of entanglement between the liner fibers and the tendency to increase the overall strength of the liner. Therefore, the resistance to folding back at the fold F and the liner at the fold F tend to increase. There is also a tendency for the external force required to fold back to increase. From this tendency, it is presumed that if the liner fiber length is larger than the predetermined upper limit fiber length, stress concentrates on the liner at the crease F and the surrounding portion, which causes a problem VI.

Therefore, the "predetermined fiber length range" of the configuration 7 is set to be equal to or greater than the predetermined lower limit fiber length and equal to or less than the predetermined upper limit fiber length. The predetermined lower limit fiber length is 0.55 [mm], preferably 0.70 [mm], and more preferably 0.90 [mm]. The predetermined upper limit fiber length is 1.60 [mm], preferably 1.45 [mm], and more preferably 1.30 [mm].
Even if the overall strength of the liner is ensured by keeping the liner fiber length within a predetermined fiber length range as described above, the smaller the orientation of the liner fibers in the lateral direction, the lower the lateral strength of the liner. Tend to do. Therefore, a predetermined orientation ratio range is specified for the fiber orientation ratio described below.

--Composition 8--
The smaller the fiber orientation ratio with respect to the configuration 8, the stronger the orientation of the liner fibers along the fold F, which tends to cause a problem VI such as cracking or avoiding the fold F. From this tendency, it is presumed that if the fiber orientation ratio is smaller than the predetermined lower limit orientation ratio, the orientation of the liner fibers along the crease F causes a problem VI.

On the other hand, the larger the fiber orientation ratio with respect to the configuration 8, the stronger the orientation of the liner fibers intersecting the fold F. There is also a tendency for the external force required for this to increase. From this tendency, it is presumed that if the fiber orientation ratio is larger than the predetermined upper limit orientation ratio, stress concentrates on the liner at the crease F and its surroundings, which causes a problem VI.

Furthermore, if the fiber orientation ratio is larger than the predetermined upper limit orientation ratio, it tends to cause breakage such as tearing or cracking due to the tensile load in the longitudinal direction, and the basic strength required for the liner is isotropic. There is a risk that the property cannot be ensured (it is not suitable for the cardboard material 1 due to the anisotropy of strength).
Therefore, the “predetermined orientation ratio range” of the configuration 8 is set to be equal to or more than a predetermined lower limit orientation ratio and equal to or less than a predetermined upper limit orientation ratio. The predetermined lower limit orientation ratio is 1.0, preferably 1.2, and more preferably 1.3. The predetermined upper limit orientation ratio is 2.0, preferably 1.8, and more preferably 1.7 or less.

--Composition 9--
The smaller the fiber length ratio with respect to the composition 9, the strength of the liner tends to decrease relative to the strength of the core. From such a tendency of strength imbalance, it is presumed that if the fiber length ratio is smaller than the predetermined lower limit ratio, the moldability of the fold F is lowered, which may be one of the causes of the problem VI. Guessed.

On the other hand, as the fiber length ratio with respect to the configuration 9 is larger, the strength of the liner tends to be relatively larger than the strength of the core, so that the drag against folding back at the fold F tends to be larger. The external force required to fold back the liner at the eye F also tends to increase. From this tendency, it is presumed that if the fiber orientation ratio is larger than the predetermined upper limit ratio, stress concentrates on the liner at the crease F and its surroundings, which causes a problem VI.

In addition, if the fiber length ratio is larger than the predetermined upper limit ratio, large irregularities are formed on the surface of the liner, and the specifications and quality required for the corrugated cardboard material 1 may not be satisfied (not suitable for the corrugated cardboard material 1). is there.
Therefore, the "predetermined fiber length ratio range" of the configuration 7 is set to be equal to or more than a predetermined lower limit ratio and not more than a predetermined upper limit ratio. The predetermined lower limit ratio is 0.65, preferably 0.80, and more preferably 0.90. The predetermined upper limit ratio is 1.90, preferably 1.60, and more preferably 1.40.

[3. Action and effect]
By providing at least one of the above-mentioned configurations a to f, the corrugated cardboard material 1 of the present embodiment can produce a box in a good state when used as a box-making material.
According to the configuration a, since the thickness dimension of the sheet 2 is within a predetermined dimension range and the planar compressive strength is within a predetermined compressive strength range, the box-making property of the corrugated cardboard material 1 can be ensured, and the box can be made. It is possible to suppress breakage of the bent portion when assembling the cardboard.
According to the configuration b, since the planar compressive strength of the sheet 2 is in a predetermined compressive strength range and the step-by-step ratio is in a predetermined magnification range, the box-making property of the corrugated cardboard material 1 can be ensured.
According to the configuration c, since the angle ratio of the sheet 2 is within a predetermined ratio range, it is possible to ensure the suitability when the cardboard material 1 is printed.
According to the configurations d and d', since the burst strength of the sheet 2 is within a predetermined burst strength range, it is possible to suppress the tearing of the box assembled from the corrugated cardboard material 1.
According to the configuration d ″, the burst strength of the portion of the double flute that does not include the fold F is within the predetermined burst strength range, and the burst strength of the portion that includes the crease F is within the predetermined burst strength range. Therefore, it is possible to suppress the tearing of the box assembled from the cardboard material 1.
According to the configuration e, since the adhesive force of the sheet 2 is within a predetermined force range, it is possible to prevent the

liners

2a and 2b of the box assembled from the cardboard material 1 from peeling off.
According to the configuration f, since the above configurations 6 to 9 are combined, damage to the fold F can be suppressed.

[II. Example]
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.
In this item [II], items common to the examples and comparative examples of configurations a to f are described in item [1], and examples and comparative examples corresponding to the respective configurations a to f are described in item [2]. .. Further, an example in which three of the configurations a to f are combined will be described in item [3].

[1. Common subject matter]
In the examples and comparative examples of the configurations a to f, the configurations common to the corrugated cardboard material (hereinafter referred to as “measurement corrugated cardboard material”) whose parameters are measured will be described.
--Measurement target--
The measurement cardboard material is a double-sided cardboard sheet.
This measured corrugated cardboard material has the following size.
・ Size: Vertical dimension 1300 [mm],
Horizontal dimension 1150 [mm],
Height dimension 1800 [mm]

--Preprocessing--
The measurement corrugated cardboard material or a part thereof, which is the measurement target of the parameters, has been pretreated for 24 hours or more under the temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000. Then, each parameter was measured.
In addition, a commonly used one-tank type starch paste was used as the adhesive for corrugated cardboard to bond the liner base paper and the core base paper. Further, the corrugated cardboard material to be measured was manufactured using a corrugator having a stepped roll.
--Evaluation--
Each of the examples and comparative examples, which will be described in detail later in the next item [2], was evaluated on a four-point scale of “◎”, “○”, “△”, and “×”.

[2. Configuration a to f]
<Structure a>
--Measurement target--
The measurement corrugated cardboard materials used in Examples a1 to a6 and Comparative Examples a7 to a14 regarding the configuration a are stepped rolls set to the number of stepped ridges of any one of the five types of stepped ridges as listed below. Manufactured in.
-Number of steps 34 [mountain / 30 cm]: Examples a1 to a6, Comparative Examples a7 to a9
-Number of steps 38 [mountain / 30 cm]: Comparative example a14
-Number of steps 40 [mountain / 30 cm]: Comparative examples a12, a13
-Number of steps 46 [mountain / 30 cm]: Comparative example a10
-Number of steps 50 [mountain / 30 cm]: Comparative example a11
The "number of steps" corresponds to the number of peaks (steps) per 30 [cm] on the sheet, and corresponds to a value obtained by dividing 30 [cm] by the wavelength of the step.

Hereinafter, with respect to Examples a1 to a6 and Comparative Examples a7 to a14, the type of flute, the step height of the stepping roll, and the basis weight of the base paper will be described.
In Examples a1 to a6 and Comparative Examples a7 to a14, either a single flute or a double flute was adopted as shown below.
Single flute: Examples a1 to a3, a5, a6 and Comparative Examples a8 to a14
-Double flute: Example a4 and Comparative Example a7

Examples a1 to a6 and Comparative Examples a7 to a14 were manufactured by a step-rolling roll set to any one of the five step heights as listed below. The "step height" is a dimension corresponding to the height of the step in the sheet of the corrugated cardboard material to be measured and corresponding to the amplitude of the step.
-Step height 0.5 [mm]: Comparative example a9
-Step height 1.5 [mm]: Example a1
-Step height 2.5 [mm]: Comparative examples a10, a11
-Step height 3.1 [mm]: Example a2
-Step height 3.4 [mm]: Comparative examples a12, a13
-Step height 3.5 [mm]: Comparative example a14
Step height 4.5 [mm]: Examples a3 to a6, Comparative Example a8
-Step height 4.7 [mm]: Comparative example a7

In Examples a1 to a6 and Comparative Examples a7 to a9, the common liner base paper shown below was used.
・ Liner base paper: 160 [g / m ² ] [MC160: manufactured by Oji Materia Co., Ltd.]
In Comparative Examples a10 to a14, liner base papers having various basis weights prepared according to the production method of Patent Publication No. 6213364 were used. Specifically, one of the following three types of basis weight was adopted. The basis weights listed here are the basis weights of the base paper that is the material (raw material) of the corrugated cardboard material to be measured.
Basis weight 120 [g / m ² ] (of liner base paper): Comparative example a14
Basis weight 170 [g / m ² ] (of liner base paper): Comparative examples a10, a12
Basis weight (of liner base paper) 200 [g / m ² ]: Comparative examples a11, a13

On the other hand, in Examples a1 to a6 and Comparative Examples a7 to a14, core base papers having various basis weights prepared according to the production method published in JP-A-2018-162526 were used. Specifically, one of the seven types of basis weights shown below was adopted for each of Examples a1 to a6 and Comparative Examples a7 to a14.
Basis weight (of core base paper) 60 [g / m ² ]: Comparative example a8
Basis weight (of core base paper) 80 [g / m ² ]: Example a6
Basis weight 120 [g / m ² ] (of core base paper): Comparative examples a10, a14
-Basis weight (of core base paper) 150 [g / m ² ]: Comparative example a11
Basis weight 170 [g / m ² ] (of core base paper): Example a5, Comparative Examples a12, a13
Basis weight 250 [g / m ² ] (of core base paper): Examples a1 to a4, Comparative example a9
Basis weight 320 [g / m ² ] (of core base paper): Comparative example a7

Measurement The basis weight of the base paper (liner base paper, core base paper) used as the material for the corrugated cardboard sheet was measured by the following procedures xa to xd.
-Procedure xa: Pre-treat the base paper for measuring the basis weight according to JIS Z0203: 2000.
-Procedure xb: Cut out the base paper to a size of 250 [mm] x 400 [mm].
-Procedure xc: The weight of the base paper cut out in procedure xb is measured with an electronic balance.
-Procedure xd: The weight measured in procedure xc is converted into the weight per unit square meter [g / m ² ].

The basis weight of the liner (base paper) forming the sheet of the corrugated cardboard material is measured by the following procedures ya to yf.
-Procedure ya: Immerse the sheet of measurement cardboard material in tap water for 15 [minutes].
-Procedure yb: The liner and core of the sheet immersed in procedure ya are peeled off by hand.
-Procedure yc: The liner peeled off in the procedure yb is dried in a dryer at 105 [° C.] for 20 [minutes].
-Procedure yd: The liner dried in the procedure yc is cut into a size of 250 [mm] x 400 [mm].
-Procedure yes: The weight of the liner cut out in the procedure yd is measured with an electronic balance.
-Procedure yf: The weight measured in the procedure y is converted into the weight per unit square meter [g / m ² ].

Further, the basis weight of the core (base paper) forming the sheet of the corrugated cardboard material is measured by the following procedures za to zg.
-Procedure za: Immerse the sheet of measurement cardboard material in tap water for 15 [minutes].
-Procedure zb: The liner, core and hand of the sheet immersed in procedure z are peeled off by hand.
-Procedure zc: The liner peeled off in procedure zb is dried in a dryer at 105 [° C.] for 20 [minutes].
-Pre-treat the liner for measuring basis weight according to procedure zd: JIS Z0203: 2000.
-Procedure ze: Cut out a liner to a size of 250 [mm] x 400 [mm]. If the waveform structure remains, cut it out to this size while stretching the wave.
-Procedure zf: The weight of the liner cut out in the procedure ze is measured with an electronic balance.
-Procedure zg: The weight measured in procedure zf is converted into the weight per unit square meter [g / m ² ].

In addition, the basis weight of the liner and core that form the sheet of the measured corrugated cardboard material is the basis weight of the base paper that is the material of the measured corrugated cardboard material, even if the same base paper is used as the measurement target. The measured value of is variable by about ± 10 [%].
For the above-mentioned corrugated cardboard material, the thickness dimensions and planar compressive strength shown in Tables 3 and 4 below were measured.

The "thickness dimension" is a parameter corresponding to the thickness of each sheet in the measured corrugated cardboard material. This thickness dimension was measured by the following procedures aa to ad.
-Procedure aa: Collect sheets for five upper and lower stages based on half the number of stages (that is, the middle stage) of the total number of stages of the corrugated cardboard material to be measured. Specifically, when the total number of stages M of the measured corrugated cardboard material is odd, the sheets for the upper and lower five stages are based on the stage obtained by rounding off the number of stages M / 2 which is half of the total number of stages of the measured corrugated cardboard material (that is, the middle stage). To collect. When the total number of stages M of the measured corrugated cardboard material was an even number, sheets for five upper and lower stages were collected based on the number of stages [(M / 2) + 1], which is half of the total number of stages of the measured corrugated cardboard material. Care was taken not to crush the steps when collecting the test pieces.
-Procedure ab: A test piece is cut out from the ten sheets collected in the procedure aa into a square having a size of 5 [cm] x 5 [cm].
-Procedure ac: Measure the thickness of the test piece cut out in procedure ab according to the following compliant standards, measuring equipment, and measuring conditions.
> Compliant standard: Corrugated cardboard industry standard T0004: 2000
> Measuring equipment: Thickness gauge (Mitutoyo Ratchet, model number K470101K)
> Measurement conditions: Plunger diameter 16 [mm], load 3923 [mN]
-Procedure ad: From the thickness measured by procedure ac, the numerical value that can be a disturbance (factor) that reduces the accuracy of the measurement result (so to speak, a numerical value that deviates greatly) is excluded, and the average value is taken as the thickness dimension. ..
In the "exclusion of numerical values that can cause disturbance" in step ad, when each numerical value measured in procedure ac is used as a population, the numerical value whose standard deviation of the population deviates from ± 3σ is excluded.

"Plane compressive strength" is a parameter corresponding to the resistance of the corrugated cardboard sheet to be crushed. This planar compressive strength was measured by the following procedures aA to aD.
-Procedure aA: In the same manner as in procedure aa, five upper and lower sheets are collected based on half the total number of steps of the measured corrugated cardboard material.
-Procedure aB: A circular test piece having a diameter of 6.4 [cm] is cut out from the ten sheets collected in the procedure aA.
-Procedure aC: Measure the planar compressive strength of the test piece cut out in step aB under the following compliant standards, measuring equipment, test speed and parallelism measurement conditions. The parallelism represents the degree of parallelism above and below the jig for plane compression.
> Compliant standard: JIS Z 0403-1: 1999
> Measuring equipment: Compression tester equipped with a jig for planar compression (manufactured by Tester Sangyo Co., Ltd.) (manufactured by A & D Co., Ltd., RTF1350)
> Test speed (measurement conditions): 12.5 ± 2.5 [m / min]
> Parallelism (measurement condition): 1/1000 or less of the compression dimension-Procedure aD: Disturbance (factor) that reduces the accuracy of the measurement result from the planar compressive strength measured in step aC, as in step a above. The plane compressive strength was taken by taking the average value, excluding the values that could be.

--Evaluation--
For Examples a1 to a6 and Comparative Examples a7 to a14 in which the thickness dimension and the planar compressive strength were measured as described above, each of the box-making property and the ruled cracking described below was evaluated.
"Box making" depends on the accuracy of the box in which the cardboard pieces (hereinafter referred to as "evaluation cardboard pieces") cut out by the cut line straddling the folds of the measured cardboard material are assembled by hand (handmade). Corresponding evaluation criteria. As a manual assembly method, the cut corrugated cardboard piece was folded at a predetermined ruled line, attached with a hot melt adhesive, and boxed.
The method of assembling the evaluation cardboard pieces by the box-making system is the same regardless of whether the evaluation cardboard pieces are assembled by hand or by the box-making system. Therefore, it can be said that the box-making property of the evaluation cardboard piece assembled by hand has a correlation with the box-making property of the evaluation cardboard piece assembled by the box-making system.

The "evaluation cardboard piece" is a test piece in which the measurement cardboard material is punched into the following shape and size with a sample cutter (CF2-1218 manufactured by Mimaki Engineering Co., Ltd.).
-Shape: Pattern in which the A-type cardboard box is developed-Size: Width dimension of the side plate of the A-type cardboard box 356 [mm],
Width dimension of the end plate of the A type cardboard box 159 [mm],
Height dimension of A type cardboard box 256 [mm]
・ Number of sheets: 100 [sheets]

The above evaluation cardboard pieces were evaluated according to the following criteria.
-⊚: All (100 [sheets]) evaluation cardboard pieces have good box-making properties.
-○: Evaluation of 100 [sheets] Of the cardboard pieces, 1 to 2 [sheets] have poor box-making properties.
-Δ: Evaluation of 100 [sheets] 3 [sheets] of the corrugated cardboard pieces have poor box-making properties.
-X: Evaluation of 100 [sheets] Of the cardboard pieces, 4 [sheets] or more have poor box-making properties.
In Example a4, in which the evaluation of “◯” was obtained with respect to the box-making property, the box-making property of 2 [sheets] was poor.

The term "good box-making property" as used herein means that the distance dimension between the following folded portions A and B in the evaluated corrugated cardboard piece is less than the predetermined distance dimension.
-Folded part A: A part where a ruled line for box making (an element different from the fold) is provided.-Folded part B: A part actually folded when assembled in a box (during box making) "Predetermined distance" The "dimensions" are 2.0 [mm] for the dimension perpendicular to the crease of the evaluation cardboard piece (MD direction) and 5 [mm] for the dimension in the direction parallel to the crease (CD direction). ].
On the other hand, "poor box-making property" means that the distance dimension between the folded portions A and B in the evaluated corrugated cardboard piece is equal to or larger than the predetermined distance dimension.

Further, "line cracking" means that the bent portion is broken when the evaluation cardboard piece is assembled into the box. This rule cracking is observed by visually observing a box whose box-making property has been evaluated (that is, a box in which evaluation cardboard pieces are assembled, hereinafter referred to as an "evaluation box").
This rule crack was evaluated according to the following criteria.
-⊚: No cracking was observed in all (100 [box]) evaluation boxes.
-○: Of the 100 [box] evaluation boxes, 1 to 2 [boxes] were cracked.
-Δ: Cracks were found in 3 [boxes] of the 100 [boxes] evaluation boxes.
-X: Of the 100 [box] evaluation boxes, 4 [boxes] or more were cracked.
Regarding Examples a3, a5, a6 and Comparative Example a8 in which the evaluation of "○" was obtained for the rule cracking, the rule cracking was observed in 1 [box] in Examples a3, a5, a6, and Comparative Example a8. In 2 [box], a crack was seen.

In Examples a1 to a6, the thickness dimension is 2.0 [mm] or more and 9.6 [mm] or less, and the planar compressive strength is 50 [kPa] or more and 250 [kPa] or less. , A good evaluation of at least "Δ" or more was obtained in both box-making property and rule cracking.
On the other hand, in Comparative Examples a7 and a9 having a thickness dimension outside the range of 2.0 to 9.6 [mm] and Comparative Examples a7 to a14 having a planar compressive strength outside the range of 50 to 250 [kPa]. A poor evaluation of "x" was obtained for the box-making property. Further, in Comparative Example a7 in which the thickness dimension was larger than 9.6 [mm], the evaluation of the rule cracking was also a poor evaluation of “x”.

From Comparative Example a7, if the thickness dimension is larger than 9.6 [mm], the liner base paper cannot be stretched and breaks when it is bent by the ruled line for box making, and the evaluation of the ruled crack is poor. Inferred.
From Comparative Examples a7 and Comparative Examples a9 to a14, if the plane compression strength is larger than 250 [kPa], it becomes difficult to insert a ruled line for box making (due to a decrease in the formability of the ruled line). It is also presumed that the box-making property is evaluated poorly because it is bent at a place other than the ruled line for the box.

From Comparative Example a8, when the planar compression strength is less than 50 [kPa], the bending strength of the evaluated corrugated cardboard piece is insufficient and it becomes easy to bend at a place other than the ruled line for box making, and the box making property is evaluated. Is presumed to be defective.
Similarly, from Comparative Example a9, when the thickness dimension is less than 2.0 [mm], the bending strength of the evaluated corrugated cardboard piece is insufficient and it becomes easy to bend at a place other than the ruled line for box making. It is presumed that the evaluation of corrugated cardboard is poor.

In view of the above Comparative Examples a7 to a14, it is presumed from Examples a1 to a6 that the smaller the thickness dimension is in the range of 9.6 [mm] or less, the more the occurrence of rule cracking is suppressed. On the other hand, it is presumed that the larger the thickness dimension in the range of 2.0 [mm] or more, the more the bending at the place other than the ruled line for box making can be suppressed.
From Examples a1 to a6, it can be inferred that if the planar compression strength is 250 [kPa] or less, defects in the ruled lines formed for box making can be suppressed. On the other hand, if the planar compression strength is 50 [kPa] or more, it is presumed that the bending strength of the evaluated corrugated cardboard piece is secured and the bending is suppressed at a place other than the ruled line for box making.
Therefore, if the thickness dimension is 2.0 [mm] or more and 9.6 [mm] or less, and the planar compressive strength is 50 [kPa] or more and 250 [kPa] or less, the box-making property It can be said that it is possible to both secure and suppress rule cracking.

<Structure b>
--Measurement target--
As the measurement corrugated cardboard materials used in Examples b1 to b3 and Comparative Examples b4 and b5 relating to the configuration b, the same liner base papers as in Examples a1 to a6 and Comparative Examples a7 to a9 were used.
In Comparative Examples b6 to b10, liner base papers having various basis weights prepared according to the production method of Patent Publication No. 6213364 were used. Specifically, one of the following three types of basis weight was adopted.
Basis weight 120 [g / m ² ] (of liner base paper): Comparative example b10
Basis weight 170 [g / m ² ] (of liner base paper): Comparative examples b7 to b9
-Basis weight (of liner base paper) 200 [g / m ² ]: Comparative example b6

In Examples b1 to b3 and Comparative Examples b4, b5 and b8, the following core base papers were used.
-Core base paper: 170 [g / m ² ] [LB170: manufactured by Oji Materia Co., Ltd.]
In Comparative Examples b6, b7, b9, and b10, core base papers having various basis weights prepared according to the manufacturing method published in JP-A-2018-162526 were used. Specifically, one of the following three types of basis weight was adopted for each of Comparative Examples b6, b7, b9, and b10.
Basis weight 120 [g / m ² ] (of core base paper): Comparative examples b9, b10
Basis weight 130 [g / m ² ] (of core base paper): Comparative example b7
-Basis weight (of core base paper) 150 [g / m ² ]: Comparative example b6

Further, the measured corrugated cardboard materials used in Examples b1 to b3 and Comparative Examples b4 to b10 are manufactured by using a corrugated board having various stepped ridges and stepped rolls having a stepped ratio shown in Tables 5 and 6 below. did.
Further, for each of Examples b1 to b3 and Comparative Examples b4 to b10, the planar compressive strength was measured in the same procedure as the above-mentioned procedures aA to aD, and the planar compressive strength shown in Tables 5 and 6 below was measured. It was measured.
Single flutes were used in Examples b1 to b3 and Comparative Examples b4 to b10.

The "step ratio" is a parameter corresponding to the magnification of the length dimension in the MD direction with respect to the liner of the core. This step-by-step rate was measured by the following procedures ba to bg.
-Procedure ba: Similar to procedures aa and aA, five upper and lower sheets are collected based on half the total number of steps of the corrugated cardboard material to be measured.
-Procedure bb: 20 [cm] in the direction in which the core peaks are continuous (horizontal direction, MD direction) from the ten sheets collected in procedure ba, and in the direction orthogonal to the core peaks (vertical direction). , CD direction) to a size of 10 [cm].
-Procedure bc: The test piece cut out in procedure bb is immersed in tap water for 24 hours.
-Procedure bd: After immersion in procedure bc, the liners on the front and back are peeled off and the core is taken out.
-Procedure be: The core taken out in step bd is stretched by hand, and the length in the fully stretched state is measured with a ruler.
-Procedure bf: The length in the direction in which the "extended length of the core" measured in procedure be and the mountain of the core of the test piece cut out in procedure bb are continuous ("the length of the original cardboard sheet"). , Here, 20 [cm]), and the step-by-step rate is calculated by the following formula b.
Step ratio = length when the core is fully extended / length of the original cardboard sheet ... Equation b
-Procedure bg: Similar to the above procedures ad and aD, the average value is taken by excluding the numerical values that may cause disturbances (factors) that reduce the accuracy of the measurement result from the step-by-step rate calculated in the procedure bf. Was taken as the step-by-step rate.

--Evaluation--
Box-making properties were evaluated for Examples b1 to b3 and Comparative Examples b4 to b10 for which the step-by-step ratio was obtained as described above. This box-making property is synonymous with the box-making property used for the evaluation of Examples a1 to a6 and Comparative Examples a7 to a14. In Example b1 in which the evaluation of “◯” was obtained with respect to the box-making property, the box-making property of 2 [sheets] was poor.

In Examples b1 to b3, the step ratio is 1.2 [times] or more and 1.7 [times] or less, and the planar compressive strength is 50 [kPa] or more and 250 [kPa] or less. Yes, a good evaluation of at least "Δ" or higher was obtained for the box-making property.
On the other hand, Comparative Example b4 in which the stepwise ratio is less than 1.2 [times] and the planar compressive strength is less than 50 [kPa], and the planar compressive strength is larger than 1.7 [times] and the planar compressive strength. Is larger than 250 [kPa] b5, a comparative example in which the stepwise compressive strength is 1.2 [times] or more and 1.7 [times] or less, but the planar compressive strength is larger than 250 [kPa]. In b6 to b10, a poor evaluation of box-making property of "x" was obtained.

From Comparative Example b4, since the step-by-step ratio is less than 1.2 [times] and the planar compressive strength is less than 50 [kPa], the bending strength of the evaluated corrugated cardboard piece is insufficient, so that the box is manufactured. It is presumed that the box-making property will be poorly evaluated because it will be easily bent at places other than the corrugated cardboard.
From Comparative Examples b5 and b6 to b10, the ruled lines for box making were not inserted because the step ratio was larger than 1.7 [times] and the planar compressive strength was larger than 250 [kPa]. It is presumed that it becomes easier (due to the decrease in the formability of the ruled line) and is bent at a place other than the ruled line for box making, resulting in poor evaluation of the box making property.

In view of the above comparative examples b4 to b10, from Examples b1 to b3, the step-by-step ratio is 1.2 [times] or more, and the planar compressive strength is 50 [kPa] or more. It is presumed that bending at places other than the ruled lines for boxes can be suppressed. Further, it is presumed that the defect of the ruled line formed for box making can be suppressed by the step-by-step ratio of 1.7 [times] or less and the planar compressive strength of 250 [kPa] or less.
Therefore, if the step ratio is 1.2 [times] or more and 1.7 [times] or less, and the planar compressive strength is 50 [kPa] or more and 250 [kPa] or less, the box is manufactured. It can be said that sex can be secured.

<Structure c>
--Measurement target--
In Examples c1 to c3 and Comparative Example c4 relating to the configuration c, the same base papers as in Examples b1 to b3 and Comparative Example b4 are used, and A produced by using a corrugator having a stepping roll of the specifications shown below. Measurement of flute A cardboard material was used.
・ Step height: 4.5 [mm]
・ Number of steps: 34 [mountain / 30 cm]
Then, the measured corrugated cardboard materials manufactured so as to have the angle ratios shown in Table 7 below were used in Examples c1 to c3 and Comparative Example c4. The unit [-] in Table 7 represents a dimensionless quantity.

The "angle ratio" is a parameter corresponding to the degree of inclination of the step in the sheet of the corrugated cardboard material to be measured. This angle ratio was measured by the following procedures ca to cf.
-Procedure ca: Take a picture of one mountain of the core in the sheet of corrugated cardboard material from the vertical direction (CD direction).
-Procedure cb: The photograph taken in procedure ca is enlarged and printed on printing paper so that one mountain has a height of 10 [cm] or more.
-Procedure cc: Draw an auxiliary line in the direction parallel to the front and back liners (that is, the lateral direction <MD direction>) and passing through the center of the front liner and the back liner (center in the TD direction).
-Procedure cd: Select any two adjacent points from the intersections of the auxiliary line and the core drawn in the procedure cc.
-Procedure ce: At each of the two points selected in the procedure cd, the acute angle of the angle formed by the auxiliary line and the core was measured with a protractor.
-Procedure cf: Calculate the ratio obtained by dividing the absolute value of the difference between the two angles (measured values) measured in the procedure ce by the sum of the two angles.

--Evaluation--
The printability of Examples c1 to c3 and Comparative Example c4 for which the angle ratio was obtained as described above was evaluated.
"Printability" is the suitability when printing is applied to the measured corrugated cardboard material, and is an evaluation standard corresponding to the quality of printing applied to the measured corrugated cardboard material.
This printability was evaluated by the following procedures cA to cC.
-Procedure cA: A sheet of corrugated cardboard material to be measured is cut into a size of 500 [mm] × 1350 [mm] having a long side in the MD direction.
-Procedure cB: Aqueous flexo ink (product number: Super-EX) engraved on 550 [lines / inch] with a direct flexo printing machine DYNA FLEX160 (manufactured by Bobst) on the test piece cut in procedure cA. FK-99, manufactured by Sakata Inc.) was applied and printed in the following order.
> Coating order: Red → ink → indigo → yellow → varnish ・ Procedure cC: The finish printed in procedure cB was visually observed.

The above printability was evaluated according to the following criteria.
-◎: There is no uneven ink deposition, and the print finish is good.
-○: There is almost no uneven ink deposition, and there is no practical problem.
-△: There is a little unevenness in ink deposition, but there is no practical problem.
・ ×: There is a great deal of uneven ink deposition, there are practical problems, and the quality is significantly inferior.

In Examples c1 to c3, the angle ratio is 0.30 or less, the printability is evaluated as “Δ” or more, and there is no practical problem. In Examples c1 and c2 having an angle ratio of 0.15 or less, an evaluation of “◯” or higher was obtained, and in Example c1 having an angle ratio of 0.05 or less, an evaluation of “⊚” was obtained.
On the other hand, in Comparative Example c4 in which the angle ratio is larger than 0.30, an evaluation of “x” is obtained for printability, which poses a practical problem.

From Comparative Example c4, it is presumed that when the angle ratio is larger than 0.30, the heights of the steps become uneven, and the evaluation of printability becomes poor. Alternatively, the fact that the test piece is likely to be deformed in the direction corresponding to the inclination of the step when the ink is applied is also a reason for presuming that the evaluation of printability is poor.
On the other hand, from Examples c1 to c3, it is presumed that when the angle ratio is 0.30 or less, the variation in the height of the steps is suppressed, and printability without any practical problem can be obtained. The variation in the height of the steps is surely suppressed by the angle ratio of 0.15 or less from Examples c1 and c2, and more by the angle ratio of 0.05 or less from Example c1. It is presumed that it will be further suppressed.
Therefore, if the angle ratio is 0.30 or less, it can be said that printability can be ensured.

<Structure d>
--Measurement target--
For Examples d1 to d3 and Comparative Example d4 regarding the configuration d, the same core base papers as in Examples b1 to b3, c1 to c3 and Comparative Examples b4 and c4 were used. On the other hand, in Examples d1 to d3 and Comparative Example d4, liner base papers having various basis weights produced according to the method for producing a liner for corrugated cardboard of Japanese Patent No. 6213364 were used. Specifically, one of the four types of basis weights shown below was adopted for each of Examples d1 to d3 and Comparative Example d4.
Basis weight (of liner base paper) 90 [g / m ² ]: Example d1
Basis weight 170 [g / m ² ] (of liner base paper): Example d2
Basis weight (of liner base paper) 250 [g / m ² ]: Example d3
Basis weight (of liner base paper) 60 [g / m ² ]: Comparative example d4
In addition, a corrugated cardboard material produced by using a corrugated board having the same stepping rolls as in Examples c1 to c3 and Comparative Example c4 was used.
The burst strength was measured for each of Examples d1 to d3 and Comparative Example d4 using the measured corrugated cardboard material produced as described above, and the burst strength shown in Table 8 below was measured.

The “burst strength” is a parameter corresponding to the easiness of tearing of the evaluation box (IFC code: 0401) targeted for evaluation of rule cracking in the above configuration a. This burst strength was measured by the following procedures da to dd.
-Procedure da: Similar to procedure aa, the sheets for the upper and lower five stages are collected based on half the total number of stages of the measured corrugated cardboard material.
-Procedure db: A test piece is cut out into a square having a size of 100 [mm] x 100 [mm] from ten sheets collected in the procedure da.
-Procedure dc: Measure the thickness of the test piece cut out in procedure db according to the following compliant standards, test pieces, measuring equipment, and measuring conditions.
> Compliant standard: JIS P 8131: 2009 (paperboard-burst strength test method)
> Measuring equipment: Murren burst tester EH, manufactured by Toyo Seiki Seisakusho Co., Ltd.
> Measurement conditions: Use a rubber diaphragm with a pressure of 170 to 220 [kpa] when expanded to a height of 10 [mm] from the tightening surface. ・ Procedure dd: Same as procedure ad, aD, pg, in procedure dc From the measured burst strength, the numerical value that could be a disturbance (factor) that reduces the accuracy of the measurement result was excluded, and the average value was taken as the burst strength.

--Evaluation--
The tearability of the evaluation box was evaluated for Examples d1 to d3 and Comparative Example d4 in which the burst strength was obtained as described above.
"Easiness of tearing" is an evaluation standard corresponding to the light and heavy load capacity of the contents contained in the box. This easiness of tearing was evaluated by the following procedures dA to dC.
-Procedure dA: The weight is housed in the evaluation box so that the weight per unit area is 15 [kgf / cm ² ]. The evaluation box was an assembly type (IFC code 0401) so as not to be affected by the tape.
-Procedure dB: After the procedure dB, two workers lift the bottom surface where the weight is not in contact with the evaluation box and hold it for 30 [seconds].
-Procedure DC: Visually check whether or not the evaluation box has been torn in procedure dB.

The above-mentioned fragility was evaluated according to the following criteria.
・ ◎: The appearance of the evaluation box has not changed at all after being lifted.
・ ○: The evaluation box is slightly torn after being lifted, but the weight remains in the evaluation box.
・ △: The evaluation box is torn after being lifted, but the weight stays in the evaluation box.
・ ×: After lifting, the evaluation box is severely torn, and the weight falls from the evaluation box.

In Examples d1 to d3, the burst strength was 500 [kPa] or more, the easiness of tearing was evaluated as “Δ” or more, and the weight did not fall. In Examples d2 and d3 having a burst strength of 1000 [kPa] or more, an evaluation of "○" or more was obtained, and in Example d3 having a burst strength of 2000 [kPa] or more, an evaluation of "◎" was obtained. ..
On the other hand, in Comparative Example d4 having a burst strength of less than 500 [kPa], an evaluation of “x” was obtained for the ease of tearing, and the weight fell.

Therefore, if the burst strength is 500 [kPa] or more, it can be said that it is possible to prevent the contents from falling out of the evaluation box. Further, if the burst strength is 1000 [kPa] or more, it can be said that damage to the evaluation box due to the load of the contents can be suppressed. Moreover, if the burst strength is 2000 [kPa] or more, it can be said that damage to the evaluation box due to the load of the contents can be prevented.
In addition, it can be seen that the larger the basis weight of the liner base paper, the higher the burst strength. From such a correlation between the basis weight and the burst strength, it can be said that if the basis weight is 80 [g / m ² ] or more, it is possible to prevent the contents from falling out of the evaluation box. Further, when the basis weight is 160 [g / m ² ] or more, it can be said that damage to the evaluation box due to the load of the contents can be suppressed. Moreover, if the basis weight is 240 [g / m ² ] or more, it can be said that damage to the evaluation box due to the load of the contents can be prevented.

<Structure d', d''>
--Measurement target--
Of Examples d10 to d24 and Comparative Examples d25 and d26 relating to the configurations d'and d', the thickness and basis weight of the measured corrugated cardboard materials of Examples d10, d11, d12 and Comparative Example d25 are described above. It is the same as the measurement corrugated cardboard material of Example d1, d2, d3 and Comparative Example d4. In each of the measured corrugated cardboard materials of Examples d13 to d24 and Comparative Example d26, the thickness and the basis weight are different from the measured corrugated cardboard materials of Examples d1, d2, d3 and Comparative Example d4 described above.

Specifically, for each of the measurement cardboard materials of Examples d10 to d24 and Comparative Examples d25 and d26, any one of the four types of flutes shown below was adopted.
・ A flute (single flute)
・ B flute (single flute)
・ E flute (single flute)
・ AB flute (double flute)

The measurement cardboard material of each flute used in each of Examples d10 to d24 and Comparative Examples d25 and d26 was produced by using a corrugator having a stepped roll of the specifications shown below.
> A flute ・ Step height: 4.5 [mm]
・ Number of steps: 34 [mountain / 30 cm]
> B flute ・ Step height: 2.5 [mm]
・ Number of steps: 50 [mountain / 30 cm]
> E flute ・ Step height: 1.1 [mm]
・ Number of steps: 85 [mountain / 30 cm]
＞ AB Flute ――A Flute――
・ Step height: 4.5 [mm]
・ Number of steps: 34 [mountain / 30 cm]
--B flute--
・ Step height: 2.5 [mm]
・ Number of steps: 50 [mountain / 30 cm]

Of the above four types of flutes, the single flutes that make up the A flute, B flute, and E flute correspond to one core (“core 2” in Tables 9 to 11 below) and two liners, respectively. It is composed of three base papers (materials). The double flute that forms the AB flute consists of three cores (“core 1”, “core 2”, and “core 3” in Tables 9 to 11 below) and five base papers corresponding to each of the two liners. It is composed of (materials).

In Examples d10 to d24 and Comparative Examples d25 and d26, one of the following ten types of corrugated cardboard base paper was used for each of the base papers forming the core or liner constituting the respective measurement cardboard materials.
・ No. 1: Basis weight 90 [g / m ² ], density 0.77 [g / cm ³ ]
・ No. 2: Basis weight 170 [g / m ² ], density 0.86 [g / cm ³ ]
・ No. 3: Basis weight 250 [g / m ² ], density 0.87 [g / cm ³ ]
・ No. 4: Basis weight 60 [g / m ² ], density 0.72 [g / cm ³ ]
・ No. 5: Basis weight 160 [g / m ² ], density 0.86 [g / cm ³ ]
・ No. 6: Basis weight 120 [g / m ² ], density 0.78 [g / cm ³ ]
・ No. 7: Basis weight 170 [g / m ² ], density 0.85 [g / cm ³ ]
・ No. 8: Basis weight 170 [g / m ² ], density 0.68 [g / cm ³ ] [LB 170: manufactured by Oji Materia Co., Ltd.]
・ No. 9: Basis weight 120 [g / m ² ], density 0.59 [g / cm ³ ] [S 120: manufactured by Oji Materia Co., Ltd.]
・ No. 10: Basis weight 280 [g / m ² ], density 0.85 [g / cm ³ ]

No. above. The method of making the base paper of No. 1 is to use softwood kraft pulp and corrugated cardboard waste paper as raw materials, make paper using a multi-layer paper machine, and have a basis weight of 90 [g / m ² ] composed of three layers. It creates a cardboard base paper. The papermaking conditions were that the cationic paper strength enhancer was contained in an amount of 0.5 [parts by mass] with respect to a total of 100 [parts by mass] of the total pulp of the paper layer, and 10 of the surface pulps were coniferous kraft pulp. It was contained in a proportion of [mass%]. In addition, all the cationic paper strength enhancers were contained in the surface layer. The softwood kraft pulp accounted for 6 [mass%] of the total pulp in the paper layer.

The above No. 1 to No. In order to adjust the density of the base paper at 10, the nip pressure was adjusted by the calendering process in the papermaking process at the time of making the base paper. The density was measured by a measuring method according to JIS P8118: 1998.
Except for the fact that the density was adjusted, the above No. 2-No. 6, No. The method for producing the base paper of No. 10 is No. 1 except for the basis weight. This is the same creation method as in 1. The above No. The method for producing the base paper of No. 7 was No. 7 except that the surface layer pulp contained softwood kraft pulp in a proportion of 50% by mass. It is the same creation method as 2.
The burst strength was measured for each of Examples d10 to d24 and Comparative Examples d25 and d26 using the measured corrugated cardboard material manufactured as described above, and the burst strength shown in Tables 9 to 11 below was measured. It was.

The burst strength was evaluated in the same way as the above-mentioned "burst strength" except that it was measured at each of the points without creases (without creases) and the points with creases (with creases). This is a parameter corresponding to the fragility of the box (IFC code: 0401).
In order to measure the burst strength without creases and the burst strength with creases, the test pieces without creases and the test pieces with creases were used for Examples d10 to d24 and Comparative Examples d25 and d26, respectively. Two types of test pieces were prepared.

For both the test piece without creases and the test piece with creases, a sample cutter (CF2-1218 manufactured by Mimaki Engineering Co., Ltd.) was used from an A4 size cardboard sheet cut out from an arbitrary stage of the measurement cardboard material. It is a test piece cut out with the following dimensions.
-Dimensions: Vertical dimension 100 [mm]
Horizontal dimension 100 [mm]
Further, the test piece with creases is a test piece having the following creases in the test piece having the above dimensions. For the measurement of the burst strength, a test piece having no creases, scratches, dents, etc. other than the intentionally provided creases is used.
・ Fold: Passes through the center of the test piece and extends along the direction of the step.
This crease is formed by processing a test piece having the above dimensions according to the following procedure.
-Procedure de: The examiner manually folds the test piece having the above dimensions at the fold position.
-Procedure df: Place the test piece created in procedure de on a flat surface, apply the following crimping equipment to the creases, and place the crimping equipment at the folds at a speed of about 10 [mm / s]. Make a round trip. Then, the test piece is left for 24 hours under temperature and humidity conditions of a temperature of 23 [° C.] and a humidity of 50 [%] in accordance with JIS Z0203: 2000.
> Crimping equipment: Product name "Tape crimping roller (manual)", manufactured by Yasuda Seiki Seisakusho, product number No. 349, roller mass: 1 [kg]
-Procedure dc: After opening the crease of the test piece (with crease) left in the procedure df, the burst strength is measured by the above procedures dc and dd.

--Evaluation--
With respect to the measured corrugated cardboard materials of Examples d10 to d24 and Comparative Examples d25 and d26, the easiness of tearing of the test piece without creases, the easiness of tearing of the test piece with creases, and the rule-breaking property evaluated.
"Easy to tear" is housed in the same box as "Easy to tear" described above, except that "Easy to tear without creases" and "Easy to tear with creases" are evaluated respectively. It is an evaluation standard corresponding to the light weight of the load capacity for the contents.

The above-mentioned "easiness of tearing without creases" and "easiness of tearing with creases" were evaluated by the following procedures dD to dI. The measurement corrugated cardboard material to be evaluated was evaluated in accordance with JIS P8111: 1989 standard.
-Procedure dD: A cube made of iron with a dimension of 1 [cm] on each side at each of the following positions on the bottom of the evaluation box (Artec Co., Ltd., product name "Density measurement body (cube)", product number: 61-6020 -21, model number: 8350) is placed. The cube is attached to each position on the bottom surface using an adhesive (product name "Aron Alpha EXTRA Impact Resistant" manufactured by Toagosei Co., Ltd.).
> Position: At the four corners of the bottom surface 30 (see FIGS. 3 and 4) of the evaluation box, a position of 80 [mm] from the vertical end toward the vertical center and from the horizontal end to the horizontal center. 4 [pieces] of cubes 31 (see FIGS. 3 and 4) are arranged with reference to the position of 50 [mm] toward the direction (see the broken line in FIG. 3).
> Dimensions of the bottom surface 30 of the evaluation box: length 210 [mm]
Horizontal 297 [mm]
The evaluation box was an assembly type (IFC code 0401) so as not to be affected by the tape.

-Procedure dE: An evaluation box in which 4 [pieces] of cubes are arranged on the bottom surface 30 in the procedure dD is placed on a pedestal 32 (see FIG. 4). The pedestal 32 (see FIG. 4) communicates to the outside with a size that allows the cube 31 (see FIGS. 3 and 4) to penetrate into a portion overlapping each of the cubes 31 (see FIGS. 3 and 4) in a top view. A space 33 (see FIG. 4) is provided.
-Procedure dF: The following stainless steel bats 34 (see FIGS. 3 and 4) are placed on the upper side of the 4 [pieces] cubes placed on the bottom surface 30 of the evaluation box in the procedure dD.
> Bat ("SUS bat"): (TRUSCO NAKAYAMA Co., Ltd., product name "Stainless steel deep type bat No. 5", product number: T-FU-7, bottom size "230 [mm] x 150 [mm]")

-Procedure dG: The weight 35 (see FIGS. 3 and 4) was allowed to stand on the SUS bat arranged in the procedure dF so that the weight per unit area was 15 [kgf / cm ² ], and 1 [hour]. put. The weight 35 (see FIGS. 3 and 4) is arranged at the center of the SUS bat 34 (see FIGS. 3 and 4) so that the load is evenly applied to each of the 4 cubes.
-Procedure dH: Visually check whether or not the evaluation box is torn in the procedure dG under each weight condition. Whether or not a tear has occurred is specifically determined by whether or not the cube has penetrated the bottom surface of the evaluation box.
-Procedure dI: The weights are changed so that the weight per unit area is 10 [kgf / cm ² ] and 5 [kgf / cm ² ] in the procedure dG, and the tests of the procedures dD to dH under each weight condition are also performed. Carried out.

As described above, the evaluation according to the procedures dD to dI is 15 [kgf / cm ² ], 10 [kgf / cm ² ] and 5 for the measurement cardboard materials of Examples d10 to d24 and Comparative Examples d25 and d26, respectively. Under the three weight conditions of [kgf / cm ² ], the evaluation of "easiness of tearing without creases" and the evaluation of "easiness of tearing with creases" are carried out respectively. The evaluation of "easiness of tearing without creases" is an evaluation in which an iron cube is placed on the bottom surface of the evaluation box where no creases are provided. The evaluation of "easiness of tearing with creases" is an evaluation in which a cube is arranged at a place where a crease is provided on the bottom surface of the evaluation box.

"Easy to tear without creases" and "Easy to tear with creases" were evaluated according to the following criteria.
・ ◎: No tearing occurs under any of the three weight conditions.
-○: 1 [location] or more is torn under the condition of 15 [kgf / cm ² ].
· △: 15,10 [kgf / cm 2] of but 1 [points] or more tear occurs (in other words 10 [kgf / cm ^2] at 1 [point] or more tear occurs in each condition, 5 [kgf / Cm ² ] does not cause tearing).
-X: One or more tears occur in any of the three weight conditions.
Of the above evaluations, those with "Δ" or higher were regarded as good evaluations. In the above criteria, the weight condition of 5 [kgf / cm ² ] is set as the criterion for evaluating "△" or more, so the weight of luggage (5 [kg]) that is often transported in the mail-order field is taken into consideration. The evaluation is carried out. In addition, since the weight condition of 15 [kgf / cm ² ] is set as the criterion for evaluating "◎", the weight upper limit (15 [kg]) of luggage that is common in the automatic box making system (fully automatic machine). ) Is taken into consideration.

"Rule splitting property" is an evaluation standard corresponding to the resistance to damage when the measured corrugated cardboard material is bent. Damage includes cracking, tearing, and tearing of the liner at the creases. The crease portion is an area including the periphery of the fold.
The evaluation of the rule-breaking property was carried out by visually confirming whether or not the liner located outside the crease had a rule-breaking at all the folds of the measured corrugated cardboard material. ..
The confirmation results were evaluated according to the following two criteria.
・ ○: No cracks were found in all the creases.
・ ×: One or more ruled cracks were found in the creases.
Of the above evaluations, "○" was regarded as a good evaluation and "×" was regarded as a poor evaluation.

In Examples d10 to d24, both the burst strength with creases and the burst strength without creases are 500 [kPa] or more, and "easiness to tear without creases" and "breakage with creases". All of "ease" were evaluated as "△" or higher.
In Examples d11 to d13 and d15 to d24 in which the burst strength with creases was 650 [kPa] or more, the easiness of tearing with creases was evaluated as “◯” or higher. In Examples d11 to d21, d23, and d24 having a crease-free burst strength of 650 [kPa] or more, an evaluation of “◯” or higher was obtained for the crease-free tearability.
In Examples d18, d21, d23, and d24 having a crease-bearing burst strength of 1500 [kPa] or more, an evaluation of “⊚” was obtained for the crease-bearing easiness of tearing. In Examples d12, d23, and d24 having a crease-free burst strength of 1500 [kPa] or more, an evaluation of “⊚” was obtained for the crease-free tearability.

On the other hand, in Comparative Examples d25 and 26 in which at least one of the crease-free burst strength and the crease-bearing burst strength is less than 500 [kPa], the crease-free rupture easiness and the crease-bearing rupture easiness at least. One of them was evaluated as "x".
Specifically, in Comparative Example d25 of a single flute, both the burst strength without creases and the burst strength with creases were less than 500 [kPa], and both the crease-free and crease-bearing tearability were indicated by "x". Was obtained. In the double flute comparative example d26, the rupture strength with creases was 500 [kPa] or more, and the fragility with creases was evaluated as “△”, but the rupture strength without creases was 500. When it was less than [kPa], the evaluation of "x" was obtained for the ease of tearing without creases.

In Examples d10 to d22 of Examples d10 to d24, both the burst strength with creases and the burst strength without creases are 2000 [kPa] or less, and the "ruledness" is "○". Was obtained.
In Examples d23 and d24 in which at least one of the crease-bearing burst strength and the crease-free burst strength is greater than 2000 [kPa] among Examples d10 to d24, an evaluation of “x” is given in terms of rule-cutting property. Obtained.

In view of Comparative Example d25 of Single Flute, from Examples d10 to d17 and d23 of Single Flute, if the burst strength of the single flute with creases is 500 [kPa] or more, the contents fall out from the evaluation box. It can be said that this can be prevented. Further, if the burst strength with creases is 650 [kPa] or more, it can be said that damage to the evaluation box due to the load of the contents can be suppressed. Moreover, if the burst strength is 1500 [kPa] or more, it can be said that damage to the evaluation box due to the load of the contents can be prevented.
On the other hand, in view of Example d23 of the single flute, from Examples d10 to d17 of the single flute, if the burst strength of the single flute with creases is 1500 [kPa] or less, all the folds of the measured corrugated cardboard material. It can be said that damage can be prevented.

In addition, it can be seen that the larger the basis weight and density of the liner base paper, the higher the burst strength. From such a correlation between the basis weight and the burst strength, if the basis weight of the liner base paper is 80 [g / m ² ] or more and the density is 0.75 [g / cm ³ ] or more in the single flute, it is evaluated. It can be said that it is possible to prevent the contents from falling out of the box. Furthermore, in the case of a single flute, if the basis weight of the liner base paper is 160 [g / m ² ] or more and the density is 0.85 [g / cm ³ ] or more, damage to the evaluation box due to the load of the contents should be suppressed. Can be said to be possible. In addition, for single flutes, if the basis weight of the liner base paper is 240 [g / m ² ] or more and the density is 0.87 [g / cm ³ ] or more, damage to the evaluation box due to the load of the contents should be prevented. Can be said to be possible.

Further, among Examples d10 to d17 and d23 of the single flute, from Examples d13 and d14 in which the material and density of the liner base paper are different, in the single flute, the pulp of the surface layer is specifically due to the difference in the material of the liner base paper. It is presumed that the greater the proportion of softwood kraft pulp contained in, the lower the burst strength tends to be. Further, among Examples d10 to d17 and d23 of the single flute, from Examples d15, d16 and d17 in which the base paper is common and only the flute is different from each other, the difference in the flute is no crease and crease is present in the single flute. It is presumed that it does not affect the burst strength.

From Examples d10 to d17, d23 and Comparative Example d25 of the single flute, it can be seen that the single flute tends to have a lower burst strength with creases than the burst strength without creases.
From Examples d10 in which the liner basis weight is relatively small and Examples d11 and d12 in which the liner basis weight is relatively large, the single flute measurement using the liner having a relatively small basis weight is compared with no crease. The burst strength with creases does not change significantly, whereas the single flute measurement cardboard material using a liner with a relatively large basis weight has creases compared to the burst strength without creases. It can be seen that the degree of decrease in burst strength is large.

In view of Comparative Example d26 of the double flute, from Examples d18 to d22 and d24 of the double flute, the burst strength without creases is 500 [kPa] or more and the burst strength with creases is 520 [kPa]. With the above, it can be said that it is possible to prevent the contents from falling out of the evaluation box. Further, from Examples d18 to d21 and d24, if the burst strength without creases is 700 [kPa] or more and the burst strength with creases is 800 [kPa] or more, the evaluation box based on the load of the contents It can be said that the damage of the box can be suppressed. Moreover, from Examples d18, d21, and d24, if the burst strength without creases is 1000 [kPa] or more and the burst strength with creases is 1500 [kPa] or more, the evaluation box based on the load of the contents It can be said that the damage can be prevented.
On the other hand, in view of Example d24 of the double flute, from Examples d18 to d22 of the double flute, if the burst strength of the double flute without creases and with creases is 2500 [kPa] or less, the corrugated cardboard material is measured. It can be said that damage can be prevented at all folds.

From Examples d18 to d22, d24 and Comparative Example d26 of the double flute, it can be seen that in the double flute, the burst strength with creases tends to be higher than the burst strength without creases. Double flute measurement In corrugated cardboard materials, when the creases are unfolded, the steps of the core are crushed by the folds, so the distance between the two liners and the three cores in the thickness direction is close. It is presumed that the rupture strength with creases is higher than that without creases because the steps of the core are crushed and overlap in the thickness direction.

In addition, even with double flutes, it can be seen that the greater the basis weight and density of the liner base paper and core base paper, the higher the burst strength. From such a correlation between the basis weight and the burst strength, in the double flute, the basis weight of the liner base paper is 80 [g / m ² ] or more and the density is 0.75 [g / cm ³ ] or more, or If the basis weight of the core base paper is 130 [g / m ² ] or more and the density is 0.65 [g / cm ³ ] or more, it can be said that it is possible to prevent the contents from falling out of the evaluation box. .. In particular, if the basis weight of the liner base paper is 80 [g / m ² ] or more and the density is 0.75 [g / cm ³ ] or more, damage to the evaluation box due to the load of the contents can be suppressed. I can say. Moreover, if the basis weight of the liner base paper is 150 [g / m ² ] or more and the density is 0.85 [g / cm ³ ] or more, damage to the evaluation box due to the load of the contents can be prevented. I can say.

<Structure e>
--Measurement target--
In Examples e1 to e3 and Comparative Example e4 regarding the configuration e, the same base papers as in Examples b1 to b3, c1 to c3, d1 to d3 and Comparative Examples b4, c4, d4 are used, and Examples c1 to c3, d1 A corrugated cardboard material for measuring A flute produced by using a corrugator having the same stepping rolls as in d3 and Comparative Examples c4 and d4 was used.
The adhesive strength was measured for each of Examples e1 to e3 and Comparative Example e4 using the measured corrugated cardboard material produced as described above, and the adhesive strength shown in Table 12 below was measured.
Regarding the notation in Table 12, "S side" means "single facer side" (back liner side), and "G side" means "glue machine side" (front liner side).

The "adhesive force" is a parameter corresponding to the peeling resistance value of the adhesive portion between the stepped top of the core (the part corresponding to the maximum value) and the liner in the sheet of the corrugated cardboard material to be measured. To put it plainly, it is a parameter corresponding to the difficulty of peeling off the liner forming the sheet of the corrugated cardboard material.
This adhesive strength was measured by the following procedures ea to ed.
-Procedure ea: Based on the number of steps of half of the total number of steps of the corrugated cardboard material to be measured, 10 upper and lower sheets are collected, and 20 sheets without deformation (for example, dents) are cut out.
-Procedure eb: From the sheet cut out in step ea, cut out a test sample to the size shown below with a cutter.
Direction parallel to the corrugated structure of the core (vertical direction <CD direction>): 50 [mm]
Direction orthogonal to the corrugated structure of the core (horizontal direction <MD direction>): 85 [mm]
-Procedure ec: Prepare ten samples on the front and back of the sample cut out in procedure eb. Specifically, ten sheets for measuring the adhesive force on the single facer side and ten sheets for measuring the adhesive force on the glue machine side are prepared.
-Procedure ed: The sample prepared in procedure ec was attached to the following measuring device, and the adhesive strength was measured under the following compliant standards and measurement conditions.
> Compliant standard: JIS Z0402: 1995
> Measuring device: Compression tester (manufactured by A & D Co., Ltd., RTF1350)
> Measurement conditions: A pin attachment (Nippon TMC Co., Ltd.) is attached to the sample, placed on the measuring device, and a load is applied at a speed of 13 [mm / min] so that the peeling surface is on the upper side. Then, measure the maximum load when the adhesive part of the sample is peeled off.
-Procedure ee: Similar to procedure ad, aD, bg, dd, the average value was taken by excluding the numerical values that could be a disturbance (factor) that deteriorates the accuracy of the measurement result from the adhesive force measured in procedure ed. The thing was made the burst strength.

--Evaluation--
The liner peeling was evaluated for Examples e1 to e3 and Comparative Example e4 in which the adhesive strength was obtained as described above.
"Liner peeling" is an evaluation standard corresponding to the quality of the box and the quality of the appearance. This liner peeling was evaluated by the following procedures eA to eC.
-Procedure eA: Similar to the evaluation of the box-making property according to the configurations a and b, the evaluation cardboard piece is cut out at the cut line straddling the crease of the measurement cardboard material. When cutting out the first evaluation cardboard piece, it was replaced with a new cutter blade, and this cutter blade was used without replacement until the 100th (last) piece.
-Procedure eB: Assemble the evaluation cardboard pieces cut out in procedure eA by hand.
-Procedure eC: Observe the presence or absence of peeling of the liner (sheet) in the evaluation box assembled in procedure eB.

The above liner peeling was evaluated according to the following criteria.
-⊚: No peeling of the liner was observed in all (100 [box]) evaluation boxes.
-○: Liner peeling was observed in 1 to 2 [boxes] of the evaluation boxes of 100 [boxes].
-△: The liner was peeled off in 3 to 4 [boxes] out of the evaluation boxes of 100 [boxes].
-X: Liner peeling was observed in 5 [boxes] of the 100 [boxes] evaluation boxes.
Regarding Examples e2 and e3 in which the evaluation of "○" was obtained for liner peeling, liner peeling was observed in 1 [box] in Example e2, and liner peeling was observed in 2 [box] in Comparative Example e3. It was observed. In addition, there were no examples or comparative examples in which a rating of "Δ" was obtained for liner peeling.

In Examples e1 to e3, the average value of the adhesive strength (hereinafter referred to as "average adhesive strength") measured on the single facer side and the glue machine side is 140 [N] or more, and the liner peeling is "○". The above evaluation was obtained. In particular, in Example e1 having an average adhesive strength of 220 [N] or more, an evaluation of “⊚” was obtained.
On the other hand, in Comparative Example 1 in which the average adhesive strength was less than 140 [N], an evaluation of "x" was obtained for the liner peeling.

If the above average adhesive strength is 140 [N] or more, the liner will not easily come off when the evaluation cardboard piece is cut out from the measurement cardboard material, and the liner will not come off easily when the evaluation box is assembled from the evaluation cardboard piece. Inferred. Furthermore, if the average adhesive strength is 220 [N] or more, it is presumed that the liner can be prevented from peeling off both when the evaluation cardboard piece is cut out and when it is assembled. Therefore, the average adhesive strength is 140 [N]. With the above, it can be said that the liner of the evaluation box is less likely to come off. As a result, it can be said that the deterioration of the appearance of the evaluation box can be suppressed and the quality of the evaluation box can be ensured.

<Structure f>
--Measurement target--
First, the configurations of the measured corrugated cardboard materials of Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20 and f33 to f36 regarding the configurations f shown in Tables 13 to 16 below will be described.

As shown in Tables 13 to 16 above, any one of the basis weights shown below is applied to the liner base papers of Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20, f33 to f36 regarding the configuration f. Adopted one basis weight. These liner base papers were produced according to the method for producing a corrugated cardboard liner of Japanese Patent No. 6213364.
・ Basis weight 120 [g / m ² ] (of liner base paper)
・ Basis weight (of liner base paper) 160 [g / m ² ]
・ Basis weight (of liner base paper) 280 [g / m ² ]
・ Basis weight (of liner base paper) 100 [g / m ² ]
・ Basis weight 320 [g / m ² ] (of liner base paper)
・ Basis weight 110 [g / m ² ] (of liner base paper)
・ Basis weight 105 [g / m ² ] (of liner base paper)

Further, in Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20 and f33 to f36, as shown in Tables 13 to 16 above, one of the two types of basis weights shown below is used. Adopted quantity. These core base papers were produced according to the production method of JP2017-218721A.
・ Basis weight 120 [g / m ² ] (of core base paper)
・ Basis weight (of core base paper) 160 [g / m ² ]
Each basis weight of the liner base paper and the core base paper described above is the basis weight of the base paper that forms the material (raw material) of the measured corrugated cardboard material, and has a temperature of 23 [° C.] and a humidity of 50 [%] in accordance with JIS Z0203: 2000. It was measured under normal conditions where pretreatment was performed for 24 hours or more under the temperature and humidity conditions of.

The measurement corrugated cardboard materials of Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20 and f33 to f36 were double-sided corrugated cardboard, and one of the five types of flutes shown below was adopted.
・ A flute ・ B flute ・ C flute ・ AB flute ・ AC flute

The measurement corrugated cardboard materials of Examples f21 to f27, f32 and Comparative Examples f35 and f36 are formed by laminating five base papers having the following basis weights in the order from one to the other in the height direction.
・ Liner base paper: Basis weight 160 [g / m ² ]
-Core base paper: Basis weight 160 [g / m ² ]
・ Medium liner base paper: Basis weight 160 [g / m ² ]
-Core base paper: Basis weight 160 [g / m ² ]
・ Liner base paper: Basis weight 160 [g / m ² ]

Further, the measurement corrugated cardboard material of Example f28 is formed by laminating five base papers having the following basis weights in the order from one to the other in the height direction.
・ Liner base paper: Basis weight 280 [g / m ² ]
-Core base paper: Basis weight 160 [g / m ² ]
・ Medium liner base paper: Basis weight 160 [g / m ² ]
-Core base paper: Basis weight 160 [g / m ² ]
・ Liner base paper: Basis weight 280 [g / m ² ]

Further, the measurement corrugated cardboard material of Example f29 is formed by laminating five base papers having the following basis weights in the order from one to the other in the height direction.
・ Liner base paper: Basis weight 160 [g / m ² ]
-Core base paper: Basis weight 120 [g / m ² ]
・ Medium liner base paper: Basis weight 120 [g / m ² ]
-Core base paper: Basis weight 120 [g / m ² ]
・ Liner base paper: Basis weight 160 [g / m ² ]

In the production of liner base paper (for front liner and back liner) that constitutes the corrugated cardboard material, a fiber classifier for raw material pulp (MAX-F700, manufactured by Aikawa Iron Works Co., Ltd.) was used to table 13 to 16 above. The pulp fiber length is adjusted as described in.
Further, in the production of the liner base paper (for the front liner and the back liner) constituting the measurement corrugated cardboard material, the jet wire ratio is adjusted when the liner base paper is made, and the above tables 13 to 16 show. The fiber orientation ratio was adjusted as described above. The jet wire ratio is the ratio (J / W) of the flow velocity (J) of the pulp dispersion to the traveling speed (W) of the wire in the paper machine. By adjusting the jet wire ratio, the flow of the dispersion liquid near the wire can be controlled in the laminar watershed.

The "fiber length" is measured by the following procedures fa to fe.
Procedure fa: The second step from the top of the corrugated cardboard material was cut into 40 [cm] squares, and the 40 [cm] square cardboard sheet was used for measurement. The cutting position was in the middle of the cardboard sheet width. Then, the cardboard sheet is immersed in ion-exchanged water for 15 minutes and removed from the ion-exchanged water.
Step fb: Each of the liner base papers (front liner and back liner) is separated from the core base paper by hand peeling from the cardboard sheet taken out in step fa so that the liner base paper is not torn.
Procedure fc: Each of the liner base paper and the core base paper separated in step fb was immersed in ion-exchanged water to adjust the concentration to 2%, and then immersed for 24 hours.
Procedure fd: After immersing each of the liner base paper and the core base paper whose concentration was adjusted by the procedure fc for 24 hours, the pulp was separated into fibers using a standard type disintegrator (manufactured by Kumagai Riki Kogyo Co., Ltd.) for 20 minutes. Disassemble into a shape.
Procedure fe: The slurry (pulp fiber) after disaggregation was separated in the procedure fd, and the fiber length in accordance with JIS P8226-2: 2011 was measured using the following fiber length measuring machine.
-Fiber length measuring machine: Part number FS-5 UHD base unit, manufactured by Valmet Co., Ltd. The "fiber length ratio" is based on the fiber length of the liner base paper and the fiber length of the core base paper measured in the above procedures fa to fe. It was calculated by the following formula f.
Fiber length ratio = Fiber length of liner base paper / Fiber length of core base paper ... Formula f

The "fiber orientation ratio" is measured by the following procedures fA to fD.
Step fA: Same as step fa above Step fB: Same as step fb above Step fC: Liner base paper and core base paper separated in step fB are each separated by a cylinder dryer (product number: MR3D, manufactured by Japo Co., Ltd.). Dry until dry.
Procedure fD: The fiber orientation ratio of the liner base paper and the core base paper dried in the procedure fC is measured using the following fiber orientation characteristic evaluation device.
-Fiber orientation characteristic evaluation device: Part number SST-2500, manufactured by Nomura Shoji Co., Ltd. The minimum value of the fiber orientation ratio is 1.0 due to the setting specifications of the above fiber orientation characteristic evaluation device.
--Evaluation--

In Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20 and f33 to f36, the crease property was evaluated for all the folds (ends) of the measured corrugated cardboard material. "Foldability" is an evaluation standard corresponding to the resistance to breakage when the corrugated cardboard material is bent. "Damage" includes cracking, tearing, and tearing of the liner base paper at creases.

In the evaluation of the crease property, it was confirmed whether or not at least one of the front liner and the back liner liner base paper was cracked at the crease, and the confirmation result was evaluated according to the following criteria. The "folded portion" is an area including the periphery of the fold.
⊚: No cracks were observed in the folds ○: 1 to 2 cracks were observed in the folds Δ: 3 to 4 cracks were observed in the folds ×: 5 or more cracks were observed in the folds In Examples f1 to f11, f21 to f32 and Comparative Examples f12 to f20 and f33 to f36, "⊚" having the highest evaluation and "○" having the next highest evaluation were regarded as good evaluations and the lowest evaluations. “×” and “Δ”, which has the next lowest evaluation, were regarded as poor evaluations.

In Examples f1 to f11 and f21 to F32, the basis weight of the liner base paper is 110 [g / m ² ] or more and 290 [g / m ² ] or less, and the pulp fiber length of the liner base paper is 0.55 [g / m ² ] or less. Mm] or more and 1.60 [mm] or less, the fiber orientation ratio is 1.0 or more and 2.0 or less, and the fiber length ratio is 0.65 or more and 1.90 or less. Yes, a rating of "○" or higher was obtained for breakability.
In particular, the basis weight of the liner base paper is 140 [g / m ² ] or more and 180 [g / m ² ] or less, and the pulp fiber length of the liner base paper is 0.90 [mm] or more and 1.30. Examples f3, f11, f23, which are [mm] or less, the fiber orientation ratio is 1.3 or more and 1.7 or less, and the fiber length ratio is 0.90 or more and 1.40 or less. In f30 to f32, the most excellent evaluation of “⊚” was obtained for the breakability.

On the other hand, in Comparative Examples f12, f13, f15, f33 to f36, the pulp fiber length of the liner base paper was out of the range of 0.55 [mm] to 1.60 [mm], and the crease property was "Δ". The following bad evaluations were obtained.
Further, in Comparative Example f14, the fiber orientation ratio was larger than 2.0, and an evaluation of “x” was obtained for the breakability. Further, in Comparative Examples f16 and f17, the fiber length ratio was out of the range of 0.65 to 1.90, and the evaluation of “Δ” was obtained for the breakability. Further, in Comparative Examples f18 to f20, the basis weight of the liner base paper was out of the range of 110 [g / m ² ] to 290 [g / m ² ], and the crease property was evaluated as “Δ” or less. ..

From Comparative Examples f12, f13, f33 to f36, since the pulp fiber length of the liner base paper is less than 0.55 [mm], the pulp fiber length is too short, so that the pulp fibers are less entangled with each other and the entire liner base paper is not entangled. It is presumed that the bending property becomes poor because the strength is weakened. From Comparative Example f15, the pulp fiber length is larger than 1.60 [mm], and from Comparative Example f14, the fiber orientation ratio is larger than 2.0, so that the liner base paper is stressed at the creases and surrounding areas. It is presumed that the breakability will be poor because of the concentration.

From Comparative Example f16, since the fiber length ratio is smaller than 0.65, the overall strength of the liner base paper is relatively low with respect to the core base paper, so that the formability of the folds is lowered and defective. It is presumed that the crackability was obtained. From Comparative Example f17, it is presumed that since the fiber length ratio is larger than 1.90, stress is concentrated on the liner base paper at the creases and the surrounding portions, so that the crease property is poor.
From Comparative Examples f18 and f19, it is presumed that since the basis weight is smaller than 110 [g / m ² ], the overall strength of the liner base paper is lowered, so that the breakability is poor. From Comparative Example f20, it is presumed that since the basis weight is larger than 290 [g / m ² ], stress is concentrated on the liner base paper at the creases and their surroundings, resulting in poor crease resistance.

In view of the above comparative examples f12 to f20 and f33 to f36, from Examples f1 to f11 and f21 to f32, the basis weight of the liner base paper is 110 [g / m ² ] or more and 290 [g / m ^2]. ] Or less, the pulp fiber length of the liner base paper is 0.55 [mm] or more and 1.60 [mm] or less, and the fiber length ratio is 0.65 or more. When it is 90 or less, the overall strength of the liner base paper is secured, and when the fiber orientation ratio is 1.0 or more and 2.0 or less, the lateral strength of the liner base paper is secured. Therefore, it is presumed that the breakability will be good.
From Examples f3, f11, f23, f30 to f32, the pulp fiber length is 0.9 [mm] or more and 1.30 [mm] or less, and the fiber orientation ratio is 1.3 or more and 1 When it is 0.7 or less, the overall strength of the liner base paper and the lateral strength of the liner base paper are raised, so that it is presumed that the breakability becomes better.

Therefore, the basis weight of the liner base paper is 110 [g / m ² ] or more and 290 [g / m ² ] or less, and the pulp fiber length of the liner base paper is 0.55 [mm] or more and 1.60. When it is [mm] or less, the fiber orientation ratio is 1.0 or more and 2.0 or less, and the fiber length ratio is 0.65 or more and 1.90 or less, breakage of creases is suppressed. I know I can do it. As a result, it can be said that the deterioration of the appearance of the cardboard box using the measured cardboard material can be suppressed, and the quality of the cardboard box can be ensured.

[3. Example of combining the three configurations]
Finally, an embodiment ade in which a part of the configuration a, d and e are combined will be described.
The details of the measurement target and evaluation of Example ade are the same as those described above unless otherwise specified.
--Measurement target--
Example ade was evaluated for the measurement corrugated cardboard material having the parameters listed below.
-Thickness dimension: 5.1 [mm]
-Rupture strength: 2009 [kpa]
-Average adhesive strength: 237.5 [N]
> Single facer side: 230 [N]
> Glue machine side: 245 [N]

--Evaluation--
Measurement of Example ade The corrugated cardboard material was evaluated for cracking, easiness of tearing, and liner peeling. As a result, excellent evaluation (“◎” mentioned above) was obtained in all of the rule cracking, the easiness of tearing, and the liner peeling.
From the evaluation results of Example ade, it can be seen that when a part of the configuration a, d, and e are combined, the evaluation corresponding to the part, d, and e of each configuration a is not impaired and is excellent.

Further, when the measured corrugated cardboard material having the above parameters is used in the box making system, it is presumed that the safety of manual work for the measured corrugated cardboard material is improved. The reasons for this include the following reasons α and β.
-Reason α: Since a good evaluation of liner peeling can be obtained, it is possible to prevent the liner from being unintentionally peeled off in the manual work on the measured corrugated cardboard material, and also to apply an appropriate force in the manual work to break the measured corrugated cardboard material. It is presumed that the liner will come off at the time of application. In other words, if the average adhesive strength is excessive, there is room for improvement in safety during breaking work.
-Reason β: If the sheet of the corrugated cardboard material to be measured is excessively thin, there is room for improvement in safety when the edge of the sheet comes into contact with the worker. Measurement If the corrugated cardboard sheet is excessively thick, there is room for improvement in safety when the liner of the sheet and the worker come into contact with each other. On the other hand, in the example ade, a good evaluation of the rule cracking is obtained, so that it is presumed that the safety when the edge of the sheet or the liner comes into contact with the worker is improved.

[III. Modification example]
The above-described embodiment is merely an example, and there is no intention of excluding the application of various modifications and techniques not specified in this embodiment. Each configuration of the present embodiment can be variously modified and implemented without departing from the gist thereof. In addition, it can be selected as needed and can be combined as appropriate.
For example, a part or all of the above-mentioned configurations a to f may be appropriately combined.
When the corrugated cardboard material is a material for a box making system, it is preferable that no additional processing such as intentionally formed notches or perforations is applied to the creases, and the corrugated cardboard material is provided on the surface layer of the liner in the corrugated cardboard material. It is preferable that the crease is a portion where the ruled line is folded back by 180 [°] from the starting point (for example, the ruled line is inside). On the other hand, when the corrugated cardboard material is a material other than that used for the box making system, processing such as cuts and perforations may be performed.

The liner base paper and core base paper used for the above-mentioned corrugated cardboard material and measurement cardboard material are not limited to the products having the product numbers mentioned in the examples, but also the liner base paper produced by the method for manufacturing a corrugated board liner of Japanese Patent No. 6213364 and JP-A-2017. A core base paper produced by the method for producing a corrugated board base paper of Japanese Patent Application Laid-Open No. -218721 may be used.

The use of the bellows-folded corrugated cardboard material described above is not limited to the use as a box-making material applied to a box-making system.
There are various ways to utilize the bellows-folded corrugated cardboard material, which is different from the conventional single-wafered corrugated cardboard sheet, and makes use of the structure in which a plurality of sheets are continuously provided through folds.
For example, the bellows-folded corrugated cardboard material can be treated as a web-like paper material having a large dimension in the extending direction in the unfolded state of the sheet.

As a method of using it as a web-like paper material, for example, the following uses can be mentioned as an example.
Use as disaster supplies: By attaching it to windows, it can be used as a measure against window cracking during typhoons, as a partition for privacy protection and stress reduction at evacuation shelters, as a cushioning material and as a rug for measures against cold. It is available.
Use at event events: It can be used for creative works such as signboards for events and school events.
Use as a building / moving material: When it is necessary to temporarily protect a door, wall, door, etc. at a building site or a moving site, it can be used as a protective material (curing material) that can be attached to an object. It can also be used as a protective material (packing material) that can be wrapped around an object.
In any of the usage methods, since the structure is such that a plurality of sheets are continuously provided through folds, there are advantages that work efficiency can be improved and dimensions in the extending direction can be secured.

[IV. Addendum]
Regarding the above embodiments, the additional notes regarding the corrugated cardboard material will be disclosed.
[Appendix 1]
In continuous double-sided corrugated cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both one direction and the second direction.
The basis weight of the liner constituting the double-sided corrugated cardboard is 110 [g / m ² ] or more and 290 [g / m ² ] or less.
The pulp fiber length of the liner is 0.55 [mm] or more and 1.60 [mm] or less.
The fiber orientation ratio, which is the ratio of the orientation of the pulp fibers in the first direction to the orientation in the second direction in the liner, is 1.0 or more and 2.0 or less.
A corrugated cardboard material characterized in that the fiber length ratio, which is the ratio of the pulp fiber length of the liner to the pulp fiber length of the core constituting the double-sided corrugated cardboard, is 0.65 or more and 1.90 or less.
[Appendix 2]
The basis weight of the liner is 140 [g / m ² ] or more and 180 [g / m ² ] or less.
The pulp fiber length of the liner is 0.90 [mm] or more and 1.30 [mm] or less.
The fiber orientation ratio is 1.3 or more and 1.7 or less.
The corrugated cardboard material according to Appendix 1, wherein the fiber length ratio is 0.90 or more and 1.40 or less.
[Appendix 3]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The thickness dimension measured in accordance with the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less.
A corrugated cardboard material having a planar compressive strength of 50 [kPa] or more and 250 [kPa] or less measured in accordance with JIS Z0403-1: 1999.
[Appendix 4]
The corrugated cardboard material according to Appendix 3, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995.
[Appendix 5]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The corrugated cardboard material according to Appendix 3 or 4, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 6]
The corrugated cardboard material according to any one of Appendix 3 to 5, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 7]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
A corrugated cardboard material having a planar compressive strength of 50 [kPa] or more and 250 [kPa] or less measured in accordance with JIS Z0403-1: 1999.
[Appendix 8]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The cardboard material according to Appendix 7, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 9]
The corrugated cardboard material according to Appendix 7 or 8, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 10]
The sheet is any one of Appendix 7 to 9, wherein the average value of the adhesive force measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more. The cardboard material described in the section.
[Appendix 11]
The sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Or the cardboard material described in item 1.
[Appendix 12]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
At the center of the front liner and the back liner when viewed from the first direction, the core intersects the virtual auxiliary line extending in the second direction, and at two adjacent locations, the core and the auxiliary line A corrugated cardboard material characterized in that the ratio obtained by dividing the difference between two acute angles formed by the two acute angles by the sum of the two acute angles is 0.30 or less.
[Appendix 13]
The corrugated cardboard material according to Appendix 12, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 14]
The corrugated cardboard according to Appendix 12 or 13, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995. Material.
[Appendix 15]
The sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Or the cardboard material described in item 1.
[Appendix 16]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The item according to any one of Appendix 12 to 15, wherein the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. Cardboard material.
[Appendix 17]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
A corrugated cardboard material having a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 18]
The corrugated cardboard material according to Appendix 17, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995.
[Appendix 19]
The sheet is described in Appendix 17 or 18, characterized in that the thickness dimension measured in accordance with the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less. Cardboard material.
[Appendix 20]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The item according to any one of Supplementary note 17 to 19, wherein the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. Cardboard material.
[Appendix 21]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The corrugated cardboard material according to any one of Appendix 17 to 20, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 22]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
A corrugated cardboard material characterized in that the average value of the adhesive strength measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more.
[Appendix 23]
The corrugated cardboard according to Appendix 22, wherein the sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Material.
[Appendix 24]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The corrugated cardboard material according to

Appendix

22 or 23, wherein the plane compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less.
[Appendix 25]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The cardboard material according to any one of Supplementary note 22 to 24, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 26]
The corrugated cardboard material according to any one of Appendix 22 to 25, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 27]
In a continuous double-flute double-sided cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. , A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the first direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The burst strength of the portion not including the crease measured in accordance with JIS P8131: 2009 is 500 [kPa] or more.
A corrugated cardboard material having a burst strength of 520 [kPa] or more at a portion including the crease measured in accordance with JIS P8131: 2009.
[Appendix 28]
The corrugated cardboard material according to Appendix 27, wherein the burst strength of the portion not including the crease and the burst strength of the portion including the fold are 2500 [kPa] or less.
[Appendix 29]
The corrugated cardboard according to Appendix 27 or 28, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995. Material.
[Appendix 30]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The item according to any one of Appendix 27 to 29, wherein the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. Cardboard material.
[Appendix 31]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The cardboard material according to any one of Supplementary note 27 to 30, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 32]
A corrugated cardboard box characterized in that the corrugated cardboard material according to any one of Supplementary notes 1 to 31 is used.

[V. Appendix-2]
[Appendix 33]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
About the cardboard piece cut out by the cut line straddling the crease
The thickness dimension measured in accordance with the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less.
A corrugated cardboard material that satisfies both the conditions that the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less.
[Appendix 34]
The corrugated cardboard material according to Appendix 33, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995.
[Appendix 35]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The corrugated cardboard material according to

Appendix

33 or 34, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 36]
The corrugated cardboard material according to any one of Supplementary note 33 to 35, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 37]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
About the cardboard piece cut out by the cut line straddling the crease
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
A corrugated cardboard material that satisfies both the conditions that the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less.
[Appendix 38]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The corrugated cardboard material according to Appendix 37, wherein the ratio obtained by dividing the difference between the two acute angles formed by the auxiliary line by the sum of the two acute angles is 0.30 or less.
[Appendix 39]
The corrugated cardboard material according to Appendix 37 or 38, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 40]
The sheet is any one of Appendix 37 to 39, wherein the average value of the adhesive force measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more. The cardboard material described in the section.
[Appendix 41]
The sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Or the cardboard material according to item 1.
[Appendix 42]
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The corrugated cardboard material is used in an automatic packaging system that automatically manufactures boxes.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
At the center of the front liner and the back liner when viewed from the first direction, the core intersects the virtual auxiliary line extending in the second direction, and at two adjacent locations, the core and the auxiliary line A corrugated cardboard material that satisfies the condition that the ratio of the difference between the two acute angles formed by the two sharp angles divided by the sum of the two acute angles is 0.30 or less (excluding 0.08 or less).
[Appendix 43]
The corrugated cardboard material according to Appendix 42, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 44]
The corrugated cardboard according to Appendix 42 or 43, wherein the sheet has an average value of adhesive strength of 140 [N] or more measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995. Material.
[Appendix 45]
Any of Appendix 42 to 44, wherein the sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Or the cardboard material according to item 1.
[Appendix 46]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The item according to any one of Appendix 42 to 45, wherein the planar compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. Cardboard material.
[Appendix 47]
In continuous cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material used in an automatic packaging system for box making in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
Regarding the liner of the cardboard piece cut out by the cut line that straddles the crease
A corrugated cardboard material characterized in that the average value of the adhesive strength measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more.
[Appendix 48]
The corrugated cardboard according to Appendix 47, wherein the sheet has a thickness dimension of 2.0 [mm] or more and 9.6 [mm] or less measured in accordance with the corrugated cardboard industry standard T0004: 2000. Material.
[Appendix 49]
The sheet is
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
The corrugated cardboard material according to Appendix 47 or 48, wherein the plane compressive strength measured in accordance with JIS Z0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less.
[Appendix 50]
The sheet is provided with the core at two locations where the core intersects and is adjacent to the virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction. The cardboard material according to any one of Supplementary note 47 to 49, wherein the ratio of the difference between the two acute angles formed by the auxiliary line divided by the sum of the two acute angles is 0.30 or less.
[Appendix 51]
The corrugated cardboard material according to any one of Supplementary note 47 to 50, wherein the sheet has a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
[Appendix 52]
A corrugated cardboard box using the corrugated cardboard material according to any one of Appendix 33 to 51.

1 Cardboard material 10th stage (wave)
2 Sheets 20 Sheets vs. 21 1st Sheet 22 2nd Sheet 23 3rd Sheet F Fold L Auxiliary Line L1 Vertical Dimension (1st Dimension)
L2 horizontal dimension (second dimension)
L3 height dimension (third dimension)

Claims

In continuous double-sided corrugated cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both one direction and the second direction.
The basis weight of the liner constituting the double-sided corrugated cardboard is 110 [g / m 2 ] or more and 290 [g / m 2 ] or less.
The pulp fiber length of the liner is 0.55 [mm] or more and 1.60 [mm] or less.
The fiber orientation ratio, which is the ratio of the orientation of the pulp fibers in the first direction to the orientation in the second direction in the liner, is 1.0 or more and 2.0 or less.
A corrugated cardboard material characterized in that the fiber length ratio, which is the ratio of the pulp fiber length of the liner to the pulp fiber length of the core constituting the double-sided corrugated cardboard, is 0.65 or more and 1.90 or less.
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The thickness dimension measured in accordance with the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less.
A corrugated cardboard material having a planar compressive strength of 50 [kPa] or more and 250 [kPa] or less measured in accordance with JIS Z0403-1: 1999.
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The step-by-step rate is 1.2 [times] or more and 1.7 [times] or less.
A corrugated cardboard material having a planar compressive strength of 50 [kPa] or more and 250 [kPa] or less measured in accordance with JIS Z0403-1: 1999.
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
At the center of the front liner and the back liner when viewed from the first direction, the core intersects the virtual auxiliary line extending in the second direction, and at two adjacent locations, the core and the auxiliary line A corrugated cardboard material characterized in that the ratio obtained by dividing the difference between the two acute angles formed by the two acute angles by the sum of the two acute angles is 0.30 or less.
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
A corrugated cardboard material having a burst strength of 500 [kPa] or more measured in accordance with JIS P8131: 2009.
In a continuous cardboard box, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
A corrugated cardboard material characterized in that the average value of the adhesive strength measured on the single facer side and the glue machine side in accordance with JIS Z0402: 1995 is 140 [N] or more.
In a continuous double-flute double-sided cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction. , A bellows-folded corrugated cardboard material in which the sheets are stacked along a third direction orthogonal to both the first direction and the second direction.
The sheet is
Under normal conditions where pretreatment was performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203: 2000.
The burst strength of the portion not including the crease measured in accordance with JIS P8131: 2009 is 500 [kPa] or more.
A corrugated cardboard material having a burst strength of 520 [kPa] or more at a portion including the crease measured in accordance with JIS P8131: 2009.
A corrugated cardboard box using the corrugated cardboard material according to any one of claims 1 to 7.