JP2021062604A - Cardboard material and cardboard box using the same - Google Patents

Abstract

To suppress breakage of a crease of a cardboard material of a bellows fold.SOLUTION: In a cardboard material 1, a rectangular sheet 2 is folded back in a second direction MD in each of creases F linearly extending along a first direction CD in a continuous double-sided cardboard, and the sheet 2 is stacked along a third direction TD. In the cardboard material 1, a length of pulp fiber of a liner is 0.55 mm or more and 1.60 mm or less. A fiber orientation ratio, which is a ratio of an orientation of the second direction MD to an orientation of the first direction CD of the pulp fiber of the liner, is 1.0 or more and 2.0 or less. A fiber length ratio, which is a ratio of a length of pulp fiber of liner base paper to a pulp fiber length of a core constituting the double-sided cardboard, is 0.65 or more and 1.90 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bellows-folded corrugated cardboard material and a corrugated 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 corrugated 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.
・ 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 corrugated cardboard material, the folds may be damaged.
This case was devised in view of the above issues, and one of the purposes is to suppress the damage of the folds. Not limited to this purpose, it is also possible that the actions and effects derived from each configuration shown in the “mode for carrying out the invention” described later and which cannot be obtained by the conventional technique are exhibited. It can be positioned as another purpose.

The cardboard material disclosed here is a continuous double-sided cardboard in which a rectangular sheet extends linearly along the first direction, and at each of the folds, the plane along the fold is orthogonal to the first direction. A bellows-folded cardboard material that is folded back in two directions and the sheets are stacked along a third direction orthogonal to both the first direction and the second direction.
In this cardboard material, 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 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 cardboard, is 0.65 or more and 1.90 or less.

According to this 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.

Hereinafter, a corrugated cardboard material and a corrugated 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 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 is multi-flute cardboard composed of two or more cores and two liners and five or more base papers corresponding to each of one or more medium liners. In this embodiment, a corrugated cardboard material made of double-sided corrugated cardboard of a single flute is mainly exemplified.

When the cardboard material is made into a box, 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 sent out in sequence, a cutting process in which the sent out 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, "Carton Wrap XL manufactured by CMC", "Carton Wrap 1000 manufactured by CMC", and "Neopost", which are fully automatic systems for automatic packaging systems. CVP-500, "TXP-600 manufactured by OS Machinery Co., Ltd.", "EM7 manufactured by Pack Size", and "Compack manufactured by Panotec", which are semi-automatic systems, 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, marked as "CD" in the figure) and the horizontal direction (second direction, marked as "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 the parameters related to the properties 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 crease F (only partly coded in FIG. 1), and the folded sheet 2 is folded back. 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 (right side 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 crease 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 wind 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 properties 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 adding the step ratio of the core to the above basis weight and multiplying the vertical dimension L1 and the horizontal dimension L2 by 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 V 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 damage to crease F ・ Viewpoint V: Suppressing peeling of liner

The above viewpoints I to V are viewpoints for solving the following problems I to V in which common ordinal numbers I to V 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 printed・ Problem IV: Easy to cause damage to the crease F ・ Problem V: Easy to cause peeling of the liner

The predetermined configurations corresponding to the above viewpoints I to V and the tasks I to V include at least one of the following configurations a to e.
-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 following configurations 4 to 7
＞ Composition 4: The basis weight of the liner is within the predetermined basis weight range ＞ Composition 5: The pulp fiber length of the liner is within the predetermined fiber length range ＞ Composition 6: The fiber orientation ratio of the liner is within the predetermined orientation ratio range > Composition 7: Fiber length ratio is within a predetermined fiber length ratio range ・ Configuration e: Adhesive strength is within a predetermined force 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 measured corrugated cardboard material.

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 planar 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 preferably 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 the predetermined compressive strength range, it is presumed that the ruled lines for box making are difficult to form, which causes the 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 the 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 measured 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>
The configuration d has the configurations 4 to 7 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 4 to 7 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 4 is a parameter representing the weight [g] per ^{liner area 1 [m 2].}
The “pulp fiber length” of configuration 5 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 configuration 6 is the ratio of the horizontal orientation to the vertical orientation of the liner fibers (MD / CD).

The "fiber length ratio" of the configuration 7 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 5 and 7, 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 found that the corrugated cardboard material 1 having all of the configurations 4 to 7 tends to effectively suppress the above-mentioned problem IV. Conversely, it was found that the corrugated cardboard material 1 which does not have any one of the configurations 4 to 7 tends to cause the problem IV.

That is, based on the above-mentioned viewpoint IV, the corrugated cardboard material 1 is provided with the configurations d of the configurations 4 to 7.
--Composition 4--
The smaller the basis weight of the liner with respect to the configuration 4, 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 IV 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 4, not only the strength of the liner tends to increase as the basis 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 the problem IV.

Therefore, the "predetermined basis weight range" of the configuration 4 is set to be equal to or more than a predetermined lower limit basis weight and equal to or less 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 5--
The shorter the liner fiber length with respect to the configuration 5, 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 the problem IV.

On the other hand, the longer the liner fiber length with respect to the configuration 5, 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). No) There is a risk.
Further, the longer the liner fiber length with respect to the configuration 5, the higher the degree of entanglement between the liner fibers and the tendency to increase the overall strength of the liner. 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, the stress concentrates on the liner at the crease F and the surrounding portion, which causes the problem IV.

Therefore, the "predetermined fiber length range" of the configuration 5 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 6--
The smaller the fiber orientation ratio with respect to the configuration 6, the stronger the orientation of the liner fibers along the crease F, which tends to cause problem IV such as cracking or avoidance of the crease 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 the problem IV.

On the other hand, the larger the fiber orientation ratio with respect to the configuration 6, the stronger the orientation of the liner fibers intersecting the fold F. Therefore, the drag against folding back at the fold F tends to increase, and the liner is folded back at 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, the stress concentrates on the liner at the crease F and the surrounding portion, which causes the problem IV.

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 6 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 7--
The smaller the fiber length ratio with respect to the composition 7, 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 IV. Guessed.

On the other hand, as the fiber length ratio with respect to the configuration 7 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, the stress is concentrated on the liner at the crease F and the surrounding portion, which causes the problem IV.

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.

<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 force 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.

[3. Action and effect]
By providing at least one of the above-mentioned configurations a to e, the corrugated cardboard material 1 of the present embodiment can manufacture 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 measured corrugated cardboard material 1 can be ensured. It is possible to suppress breakage of the bent portion when assembling into a box.
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 measured 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 measurement cardboard material 1 is printed.
According to the configuration d, since the above configurations 4 to 7 are combined, damage to the fold F can be suppressed.
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 measurement cardboard material 1 from peeling off.

[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 e are described in item [1], and examples and comparative examples corresponding to each of configurations a to e are described in item [2]. .. Further, an example in which three of the configurations a to e are combined will be described in item [3].

[1. Common subject matter]
In the examples and comparative examples of the configurations a to e, a configuration common to the corrugated cardboard material (hereinafter referred to as “measurement corrugated cardboard material”) for which the parameter is 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 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 e]
<Structure a>
--Measurement target--
The measurement corrugated cardboard materials used in Examples a1 to a6 and Comparative Examples a7 to a9 regarding the configuration a were produced using a corrugator having a stepped roll having a stepped number of 34 [mountain / 30 cm]. The "number of steps" corresponds to the number of peaks (steps) per 30 [cm] on the sheet, and corresponds to a numerical 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 a9, 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 a9, 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, a9
-Double flute: Example a4 and Comparative Example a7

Examples a1 to a6 and Comparative Examples a7 to a9 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 3.1 [mm]: Example a2
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.]
On the other hand, in Examples a1 to a6 and Comparative Examples a7 to a9, 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 five types of basis weights shown below was adopted for each of Examples a1 to a6 and Comparative Examples a7 to a9. 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 (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 170 [g / m ² ] (of core base paper): Example a5
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: Pretreatment of base paper for measuring basis weight in accordance with JIS Z0203: 2000
To do.
-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 the weight per unit square meter [g / m ^2]
] Is converted.

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, core and hand of the sheet immersed in procedure ya are peeled off by hand.
-Procedure yc: The liner peeled off in procedure yb is dried in a dryer at 105 [° C.] for 20 [minutes].
dry.
-Procedure yd: The liner dried in the procedure yc is 250 [mm] x 400 [mm] size.
Cut out to.
-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 procedure y is the weight per unit square meter [g / m ^2]
] Is converted.

Further, the basis weight of the core (base paper) forming the sheet of the corrugated cardboard material is measured by the following procedure 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].
dry.
-Procedure zd: JIS Z0203: 2000 to measure the basis weight in accordance with the liner
Make sense.
-Procedure ze: Cut out a liner to a size of 250 [mm] x 400 [mm]. In addition, the wave
If the shape structure remains, cut it out to this size while keeping the waves stretched.
Su.
-Procedure zf: The weight of the liner cut out in the procedure ze is measured with an electronic balance.
-Procedure zg: The weight measured by procedure zf is the weight per unit square meter [g / m ^2]
] Is converted.

In addition, the basis weight of the liner and core that make up the sheet of corrugated cardboard to be measured is the basis weight of the base paper that is the material of the measurement cardboard, even if the same base paper is used as the measurement target. The measured value of can fluctuate by about ± 10 [%].
For the above-mentioned measured corrugated cardboard material, the thickness dimension and the planar compressive strength shown in Table 3 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: If the total number of stages M of the measured corrugated cardboard material is odd, round off to half the number of stages M / 2.
Collect the upper and lower five tiers of sheets based on the inserted tier (that is, the middle tier).
To. When collecting the test pieces, care was taken not to crush the steps. all
If the number of steps M is an even number, five steps up and down based on half the number of steps ((M / 2) + 1)
Collect a minute sheet.
-Procedure ab: 5 [cm] x 5 [cm] size from 10 sheets collected in procedure aa
Cut out a test piece into a square.
-Procedure ac: Measure the thickness of the test piece cut out in procedure ab according to the following standards, measuring equipment, and measurement.
Measure under constant 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: A disturbance that reduces the accuracy of the measurement result from the thickness measured by procedure ac (required)
Exclude numerical values that can be (cause) (so to speak, numerical values that deviate greatly), and calculate the average value.
The thickness was taken.
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 to crushing of the sheet of the measured corrugated cardboard material. This planar compressive strength was measured by the following procedures aA to aD.
-Procedure aA: Similar to procedure aa, when the total number of stages M of the measured corrugated cardboard material is odd, it is halved.
Five steps above and below based on the rounded step (that is, the middle step) of the number of steps M / 2.
Collect a minute sheet. When collecting test pieces, the steps will not be crushed.
I was careful. If the total number of stages M is an even number, half the number of stages ((M / 2) + 1
) As a reference, collect the upper and lower five-tiered sheets.
-Procedure aB: A circular test with a diameter of 6.4 [cm] from ten sheets collected in procedure aA.
Cut out a test piece.
-Procedure aC: Measure the planar compressive strength of the test piece cut out in step aB according to the following standard and measurement.
Measure under the measurement conditions of equipment, test speed, and parallelism. The parallelism is flat.
Indicates the degree of parallelism between the top and bottom of the jig for surface compression.
> Compliant standard: JIS Z 043-1: 1999
> Measuring equipment: Compression with a jig for flat compression (manufactured by Tester Sangyo Co., Ltd.)
Testing machine (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 compressive dimension-Procedure aD: Measured from the plane compressive strength measured in step aC in the same way as step a above.
Exclude numerical values that can cause disturbances (factors) that reduce the accuracy of constant results, and are flat.
The average value was taken as the plane compression strength.

--Evaluation--
For Examples a1 to a6 and Comparative Examples a7 to a9 in which the thickness dimension and the planar compressive strength were measured as described above, the box-making property and the ruled cracking described below were 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 are poor in box-making property.
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 provided with a ruled line for box making (an element different from the fold) -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 "evaluation box").
This rule crack was evaluated according to the following criteria.
-⊚: No cracking was observed in all (100 [box]) evaluation boxes.
◯: Among the evaluation boxes of 100 [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 a9 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 this comparative example a7, 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), and the ruled line for box making is not formed. It is also presumed that it will be bent and the evaluation of box-making property will be poor.

From Comparative Example a8, when the plane 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 a9, 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 plane 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 cardboard materials used in Examples b1 to b3 and Comparative Examples b4 and b5 regarding the configuration b, the same liner base papers as in Examples a1 to a6 and Comparative Examples a7 to a9 were used, and the following core base papers were used.
-Core base paper: 170 [g / m ² ] [LB170: manufactured by Oji Materia Co., Ltd.]
Further, the measurement corrugated cardboard materials used in Examples b1 to b3 and Comparative Examples b4 and b5 were produced by using a corrugated board having a stepping roll having various stepping rates shown in Table 4 below. Further, for each of Examples b1 to b3 and Comparative Examples b4 and b5, 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 Table 4 below was measured. ..

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, when the total number of stages M of the measured corrugated cardboard material is odd,
Above based on the rounded stage (that is, the middle stage) of half the number of stages M / 2.
Collect the lower five sheets. When collecting the test piece, the stage is crushed.
I was careful not to. If the total number of stages M is an even number, half the number of stages ((M / 2)
) +1), and collect the upper and lower five-tiered sheets.
-Procedure bb: The direction in which the core peaks are continuous from the ten sheets collected in procedure ba (horizontal)
20 [cm] in the direction (MD direction) and orthogonal to the center peak (vertical)
Cut out to a size of 10 [cm] in the direction (direction, CD direction).
-Procedure bc: The test piece cut out in procedure bb is immersed in tap water for 24 hours.
-Procedure bd: After the immersion in procedure bc, the liners on the front and back are peeled off and the core is taken out.
-Procedure be: The length of the core taken out in step bd is stretched by hand and fully extended.
With a ruler.
-Procedure bb: The "extended length of the core" measured in procedure be and cut out in procedure bb.
The length of the core of the test piece in the continuous direction ("Original cardboard sheet"
The step ratio is called "length", here 20 [cm]), and the following formula b is used.
Is calculated.
Stepping rate = length with the core fully extended / length of the original cardboard sheet ... Equation b
-Procedure bg: Measured from the step-by-step rate calculated in procedure bf in the same manner as in steps ad and aD above.
Exclude numerical values that can cause disturbances (factors) that reduce the accuracy of constant results, and are flat.
The average value was taken as the step-by-step rate.

--Evaluation--
The box-making property was evaluated for Examples b1 to b3 and Comparative Examples b4 and b5 for which the step-by-step ratio was obtained as described above. This box-making property is synonymous with the box-making property used in the evaluation of Examples a1 to a6 and Comparative Examples a7 to a9. 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 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 greater than 1.7 [times]. In Comparative Example b5 in which the value is larger than 250 [kPa], a poor evaluation of “x” in the box-making property 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 Example b5, since the step ratio is larger than 1.7 [times] and the planar compressive strength is larger than 250 [kPa], it becomes difficult to insert a ruled line for box making (ruled line formability). It is presumed that the box-making property is evaluated poorly because it is bent at a place other than the ruled line for box-making.

In view of the above comparative examples b4 and b5, from Examples b1 to a3, 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 ensured.

<Structure c>
--Measurement target--
In Examples c1 to c3 and Comparative Example c4 regarding 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 5 below were used in Examples c1 to c3 and Comparative Example c4. The unit [-] in Table 5 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: In the sheet of corrugated cardboard material for measurement, one mountain of the core is vertically oriented (CD direction).
Take a photo from Mukai).
-Procedure cb: The height of one mountain is 10 [cm] or more in the photograph taken in procedure ca.
Enlarge and print on printing paper.
-Procedure cc: The direction parallel to the liners on the front and back (that is, the lateral direction <MD direction>).
Draw an auxiliary line that passes through the center of the front liner and back liner (center in the TD direction).
-Procedure cd: Of the intersections between the auxiliary line drawn in procedure cc and the core, any two adjacent points
select.
-Procedure ce: At each of the two points selected in procedure cd, the auxiliary line and the core are formed.
The acute angle of the angles was measured with a protractor.
-Procedure cf: Two absolute values of the difference between the two angles (measured values) measured in procedure ce
Calculate the ratio divided by the sum of the angles of.

--Evaluation--
The printability of Examples c1 to c3 and Comparative Example c4 from which the angle ratios were 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: Measurement cardboard sheet is 500 [mm] x 1 with the long side in the MD direction.
Cut to a size of 350 [mm].
-Procedure cB: Direct flexo printing machine D for the test piece cut in procedure cA.
550 [Line / Inn] by YNA FLEX160 (manufactured by Bobst)
Aqueous flexo ink with Anilox roll engraved on Chi] (Product number: Su
Apply with per-EX FK-99 (manufactured by Sakata Inc.) in the following order.
I printed it.
> 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 problem in practical use 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--
First, the configurations of the measured corrugated cardboard materials of Examples d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36 regarding the configurations d shown in Tables 6 to 9 below will be described.

As shown in Tables 6 to 9 above, any one of the basis weights shown below is used on the liner base papers of Examples d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36 relating to the configuration d. Adopted one basis weight. These liner base papers were produced according to the method for producing corrugated cardboard liners of Japanese Patent No. 6213364.
・ Basis weight 120 [g / m ² ] (of liner base paper)
・ Basis weight 160 [g / m ² ] (of liner base paper)
・ 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 d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36, as shown in Tables 6 to 9 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 ]
The basis weights of the liner base paper and the core base paper described above are the basis weights of the base paper that forms the material (raw material) of the corrugated cardboard material to be measured. It was measured in a normal state where pretreatment was performed for 24 hours or more under the temperature and humidity conditions of.

The measurement corrugated cardboard materials of Examples d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36 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 d21 to d27, d32 and Comparative Examples d35 and d36 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 d28 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 d29 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 6 to 9 above. As described in, the pulp fiber length is adjusted.
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 6 to 9 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 da to de.
Procedure da: Cut out the second step from the top of the corrugated cardboard material into 40 [cm] squares, and that 40
A [cm] square cardboard sheet was used for measurement. The cutout position is cardboard
It was in the middle of the seat width. Immerse the cardboard sheet in ion-exchanged water for 15 minutes
Pickle and remove from ion-exchanged water.
Step db: Liner base paper (front liner and front liner) from the cardboard sheet taken out in step da
By peeling off each of the back liners) by hand so that the liner base paper is not torn.
Separate from the core base paper.
Procedure dc: Ion-exchanged water is used to separate the liner base paper and the core base paper separated in step db.
Soaked in, adjusted to a concentration of 2%, and then soaked for 24 hours.
Procedure dd: 24 for each of the liner base paper and the core base paper whose density was adjusted by the procedure dc.
After soaking for a while, dissociate for 20 minutes using a standard disassembly machine (manufactured by Kumagai Riki Kogyo Co., Ltd.).
Then, the pulp is decomposed into fibers.
Procedure de: The slurry (pulp fiber) after disintegration is separated in step dd, and the following fiber length measurement is performed.
Using a machine, measure fiber length in accordance with JIS P8226-2: 2011
did.
-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 da to de. It was calculated by the following formula d.
Fiber length ratio = Fiber length of liner base paper / Fiber length of core base paper ... Formula d

The "fiber orientation ratio" is measured by the following procedures dA to dD.
Step dA: Same as step da above Step dB: Same as step db above Step dB: Cylinder each of the liner base paper and core base paper separated in step dB.
Moisture is eliminated by the rye (product number: MR3D, manufactured by Japo Co., Ltd.)
To dry.
Step dD: The fiber orientation ratio of the liner base paper and the core base paper dried in step dC is determined by the following fiber arrangement.
Directional characterization device Measure using the characteristics.
-Fiber length measuring machine: Part number FS-5 UHD base unit, manufactured by Valmet Co., Ltd. The minimum value of the fiber orientation ratio is 1.0 due to the setting specifications of the above fiber length measuring machine.
--Evaluation--

In Examples d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36, 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 the 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 d1 to d11, d21 to d32 and Comparative Examples d12 to d20 and d33 to d36, "⊚" 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 d1 to d11 and d21 to d32, 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 d3, d11, d23, 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 d30 to d32, the most excellent evaluation of “⊚” was obtained for the breakability.

On the other hand, in Comparative Examples d12, d13, d15, d33 to d36, the pulp fiber length of the liner base paper was out of the range of 0.55 [mm] to 1.60 [mm], and the breakability was "Δ". The following bad evaluations were obtained.
Further, in Comparative Example d14, the fiber orientation ratio was larger than 2.0, and an evaluation of “x” was obtained for the breakability. Further, in Comparative Examples d16 and d17, 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 d18 to d20, 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 d12, d13, d33 to d36, since the pulp fiber length 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 overall strength of the liner base paper is increased. Since it becomes weak, it is presumed that the breakability becomes poor. From Comparative Example d15, the pulp fiber length is larger than 1.60 [mm], and from Comparative Example d14, the fiber orientation ratio is larger than 2.0. It is presumed that the breakability will be poor because of the concentration of fibers.

From Comparative Example d16, 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 d17, 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 d18 and d19, 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 d20, ^{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 the surrounding portions, so that the crease property is poor.

In view of the above comparative examples d12 to d20 and d33 to d36, from Examples d1 to d11 and d21 to d32, 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 d3, d11, d23, d30 to d32, 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 breakage property 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 appearance of the corrugated cardboard box using the measured corrugated cardboard material can be suppressed from being deteriorated, and the quality of the corrugated cardboard box can be ensured.

<Structure e>
--Measurement target--
For 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 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 10 below was measured.
Regarding the notation in Table 10, "S side" means "single facer side" (back liner side), and "G side" means "glue machine side" (front liner side).

"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 to be measured.
This adhesive force was measured by the following procedures ea to ee.
-Procedure ea: If the total number of stages M of the measured corrugated cardboard material is odd, round off to half the number of stages M / 2.
Collect the upper and lower ten tiers of sheets based on the inserted tier (that is, the middle tier).
, Cut out 20 sheets without deformation (for example, dent). All stages M
In the case of an even number, the sea for the upper and lower ten steps is based on half the number of steps ((M / 2) + 1).
Twenty sheets without deformation (for example, dents) are cut out.
-Procedure eb: From the sheet cut out in step ea, the size shown below is the size of the test sun.
Sample cutter for pull (manufactured by Mimaki Engineering Co., Ltd., CF
Cut out using 2-1218).
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. Ingredients
Physically, ten sheets for measuring the adhesive strength on the single facer side and a guru
-Prepare 10 sheets to measure the adhesive strength on the machine side.
-Procedure ed: The sample prepared in procedure ec is attached to the following measuring device and conforms to the following.
Adhesive strength was measured according to the standard and measurement conditions.
> Compliant standard: JIS Z0402: 1995
> Measuring device: Compression tester (manufactured by A & D Co., Ltd., RTF1350)
> Measurement conditions: Pin attachment (Nippon TMC Co., Ltd.) is attached to the sample.
Then, place it on the measuring device and place it on the measuring device so that the peeling surface is on the upper side, 13 [mm / min.
], And the maximum load when the adhesive part of the sample is peeled off.
Measure the weight.
-Procedure ed: As with steps ad, aD, and aC, is the adhesive strength measured in step ed?
Exclude numerical values that can cause disturbances (factors) that reduce the accuracy of measurement results.
The average value was taken as 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: Straddle the crease of the measured corrugated cardboard material as in the evaluation of the box-making property of the configurations a and b
Evaluation with a cut line Sample cutter (Mimakie Co., Ltd.)
Cut out using CF2-1218) manufactured by Engineering. In addition, one
Evaluation of the first piece When cutting out a cardboard piece, replace it with a new cutter blade.
, I used this cutter blade without replacing it until the 100th (last).
-Procedure eB: Assemble the evaluation cardboard pieces cut out in procedure eA by hand. "Review
"Value cardboard piece" is a sample of the measured cardboard material in the following shape and size.
Lucter (manufactured by Mimaki Engineering Co., Ltd., CF2-1218
), The following number of test pieces are punched out.
Shape: Pattern with A-type cardboard box unfolded
Size: Width dimension of side plate of 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]
-Procedure eC: Peeling of the liner (sheet) in the evaluation box assembled in step eB
Observe the presence or absence.

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 force measured on the single facer side and the glue machine side (hereinafter referred to as "average adhesive force") 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]. If it is the above, it can be said that the liner of the evaluation box is hard 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.

[3. Example of combining the three configurations]
Finally, an embodiment abc in which the configurations a, b and c are combined will be described.
The details of the measurement target and evaluation of Example abc are the same as those described above unless otherwise specified.
--Measurement target--
Example abc was evaluated for the measurement corrugated cardboard material having the parameters listed below.
-Thickness dimension: 5.1 [mm]
-Plane compressive strength: 170 [kpa]
・ Angle ratio: 0.00
-Average adhesive strength: 237.5 [N]
> Single facer side: 230 [N]
> Glue machine side: 245 [N]

--Evaluation--
For the corrugated cardboard material measured in Example abc, box-making property, rule cracking, printability, and liner peeling were evaluated. As a result, excellent evaluation (“◎” mentioned above) was obtained in all of box-making property, rule cracking, printability, and liner peeling.
From the evaluation results of Example abc, it can be seen that when the configurations a, b, and c are combined, the evaluation corresponding to each of the configurations a, b, and c is not impaired and is excellent.

Further, when the measurement cardboard material having the above parameters is used in the box making system, it is presumed that the box assembly speed (packaging speed) can be increased. The reasons for this include the following reasons α and β.
・ Reason α: Since a good evaluation of liner peeling can be obtained, the liner peeling is suppressed.
One, the process of cutting out the measurement cardboard material into evaluation cardboard pieces (that is, "su"
It is presumed that the speed of "liter processing") can be increased. In other words
High-speed corrugated cardboard material to be cut out by slitter in liter processing
Even if it is cut out with, it is presumed that the liner will not come off easily due to the impact.
When.
・ Reason β: Since a good evaluation of box-making property can be obtained, box-making property is ensured and box-making property is ensured.
It is presumed that the packaging speed of the system can be increased. In other words, evaluation
Equipment unit for assembling cardboard pieces (for example, robot arm for packaging)
) Even if the cardboard material to be assembled is folded at high speed, it will be on the ruled line.
It is presumed that it will bend (the bending at places other than the ruled lines will be suppressed).
To be.

[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, when the corrugated cardboard material is a material for a box-making system, it is preferable that no additional processing such as intentionally formed cuts or perforations is applied to the surface layer of the liner in the corrugated cardboard material. It is preferable that the crease is a portion that is folded back by 180 [°] from the provided ruled line as 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 cardboard liner of Japanese Patent No. 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.

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 (12)

In a continuous 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 cardboard material in which the sheets are stacked along a third direction orthogonal to both one direction and the second direction.
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 liner to the orientation in the first direction, 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. 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 claim 1, wherein the fiber length ratio is 0.90 or more and 1.40 or less. The sheet is
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.
The corrugated cardboard material according to claim 1 or 2, wherein the plane compressive strength measured in accordance with JIS Z 0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. The thickness dimension is 5.1 [mm] or more, and the thickness dimension is 5.1 [mm] or more.
The corrugated cardboard material according to claim 3, wherein the plane compressive strength is 170 [kPa] or more. The sheet according to claim 1 or 2, 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. Cardboard material. The cardboard material according to claim 5, wherein the average value of the adhesive strength is 190 [N] or more. 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 claim 1 or 2, 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. The cardboard material according to claim 7, wherein the ratio divided by the sum of the two acute angles is 0.15 or less. The step rate is 1.2 [times] or more and 1.7 [times] or less.
The sheet according to claim 1 or 2, wherein the planar compressive strength measured in accordance with JIS Z 0403-1: 1999 is 50 [kPa] or more and 250 [kPa] or less. Cardboard material. The step-by-step rate is 1.5 [times] or more,
The corrugated cardboard material according to claim 9, wherein the plane compressive strength is 170 [kPa] or more. The corrugated cardboard material according to any one of claims 1 to 10, wherein the double-sided corrugated cardboard is an A flute. A cardboard box using the cardboard material according to any one of claims 1 to 11.

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