JP6697615B1 - Cardboard material and cardboard box using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a carton box and a carton box in good condition. SOLUTION: A corrugated cardboard material 1 in a bellows fold is a continuous cardboard, and a rectangular sheet 2 linearly extends along a first direction CD (a direction perpendicular to the paper surface) in a second direction MD at each fold. The sheets 2 are folded back and stacked in the third direction TD. According to JIS Z0203, this sheet 2 is pretreated for 24 hours or more under the temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in a normal state, and when viewed from the first direction CD, the front liner 2 a Two acute angles θ1 formed by the center core 2c and the auxiliary line L at two adjacent points where the center core 2c intersects the virtual auxiliary line L extending in the second direction MD at the center between the center liner 2b and the back liner 2b. , Θ2 divided by the sum of the two acute angles θ1 and θ2 is 0.30 or less. [Selection diagram] Figure 2

Description

  The present invention relates to a corrugated cardboard material and a cardboard box using the corrugated cardboard material.

  A corrugated cardboard material (also called “fanfold”) is known as a material for box manufacturing. The cardboard material is provided with folds between continuous rectangular sheets, and the sheets are alternately folded back at the folds. In such a corrugated cardboard material, continuous sheets are stacked vertically and folded into a rectangular parallelepiped shape.

The above cardboard materials are used as packaging materials for box-making systems (also called "automatic packaging systems" or "three-sided variable systems") that manufacture boxes of the optimal size according to the size of the packaging target. .. In this box making system, various steps exemplified below are carried out.
・ Feeding process: Process of feeding the corrugated cardboard material ・ Cut process: Process of cutting the flat cardboard material fed in the feeding process ・ Fold process: Process of assembling the box from the corrugated cardboard material cut in the cutting process ・ Printing process : Process of printing on flat or assembled cardboard material ・ Packing process: Process of storing contents in a box to be assembled

Special table 2013-513869 bulletin

However, when a corrugated corrugated cardboard material is used as a material for a box making system, the state of the manufactured box may be poor depending on the properties of the sheet used for the cardboard material.
This case was created in view of the above problems, and one of the purposes is to manufacture a box in a good condition. It should be noted that the present invention is not limited to this purpose, and the actions and effects derived from the respective configurations shown in "Modes for Carrying Out the Invention" described below, which are not obtained by the conventional technique, can also be obtained. It can be positioned for other purposes.

The corrugated cardboard disclosed herein is a continuous corrugated cardboard in which each of the folds in which a rectangular sheet linearly extends along the first direction is a second plane orthogonal to the first direction on a plane along the folds. A corrugated cardboard material that is folded back in a direction and has the sheets stacked in a third direction orthogonal to both the first direction and the second direction.
Regarding the properties of the sheet, the cardboard material is the sheet measured in a normal state after pretreatment for 24 hours or more under the temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] according to JIS Z0203. It has a predetermined configuration which is a parameter of.
The predetermined configuration includes at least one of the configurations a to e shown below.

The configuration a includes the following configurations 1 and 2.
The configuration 1 includes that the thickness dimension measured according to the corrugated board industry standard T0004: 2000 is 2.0 [mm] or more and 9.6 [mm] or less.
The configuration 2 includes that the plane compressive strength measured according to JIS Z0403-1 is 50 [kPa] or more and 250 [kPa] or less.

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

  In the configuration c, the center core intersects with a virtual auxiliary line extending in the second direction at the center of the front liner and the back liner when viewed from the first direction, and the center core is provided at two adjacent positions. And a ratio between the two acute angles formed by the auxiliary line and the auxiliary line divided by the sum of the two acute angles is 0.30 or less.

  The configuration d includes that the burst strength measured according to JIS P8131 is 500 [kPa] or more.

  The configuration e includes that the average value of the adhesive forces measured on the single facer side and the glue machine side according to JIS Z0402 is 140 [N] or more.

  According to the present case, the box in good condition can be manufactured.

It is a perspective view which shows the corrugated cardboard material. It is a schematic diagram which shows an example of the step in the sheet | seat used for the corrugated cardboard material of a bellows fold.

Hereinafter, a cardboard material and a cardboard box as an embodiment will be described.
The cardboard material of the present embodiment is a bellows-folded box-making material in which a rectangular sheet is folded in a continuous cardboard. A double-sided cardboard having liners on both sides of the core is used as the cardboard material.

  When the cardboard material is made into a box, it becomes a cardboard box. More specifically, the corrugated cardboard material used for 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 into the development pattern of the box, and folding into the shape of the box. Boxes are made into cardboard boxes after undergoing various processes such as the standing process. The box making system for assembling the cardboard box is not particularly limited, but is, for example, a fully automatic system of an automatic packaging system (CMC, Carton Wrap 1000), (Neopost, CVP-500), (OSM Scenary). , TXP-600), semi-automatic system (Pack Size, EM7), (Panotec, Compaq) can be used.

In this embodiment, an example in which the following directions I and II correspond as shown in Table 1 below is given, and the cardboard material is assumed to be placed on a horizontal surface.
-Direction I: Direction in a cardboard material placed on a horizontal surface-Direction II: Direction in a semi-finished product in the process of manufacturing the cardboard material

  The longitudinal direction (first direction, referred to as "CD" in the figure) and the lateral direction (second direction, referred to as "MD" in the figure) are horizontal directions, and along the sheet (fold). The direction in which the plane extends. The vertical direction and the horizontal direction are orthogonal to each other. The height direction (third direction, referred to as "TD" in the drawing) 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 stacked.

The MD (Machine Direction) direction is also referred to as “flow direction”, and is the direction in which the corrugated board manufacturing process progresses from upstream to downstream. The CD (Cross Direction) direction is a direction orthogonal to the MD direction on 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 the present embodiment means a range of the numerical value X or more and the numerical value Y or less.

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

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

Here, the folded structure of the corrugated cardboard material 1 will be described by focusing on three continuous sheets 2 (shown by a chain double-dashed line in FIG. 1).
First sheet 21: Sheet 2 continuous to one side of second sheet 22
Second sheet 22: Sheet 2 that is continuous with both the first sheet 21 and the third sheet 23
-Third sheet 23: Sheet 2 continuous to the other side of second sheet 22

A first fold F1 is provided between the first sheet 21 and the second sheet 22, and the sheets 21 and 22 are continuous through the first fold F1. The second fold F2 is provided between the second sheet 22 and the third sheet 23, and the sheets 22 and 23 are continuous through the second fold F2.
The first fold F1 is a fold F in which the second sheet 22 is folded back toward one side (rightward in FIG. 1) in the lateral direction with respect to the first sheet 21, and the other side (in the lateral direction of the cardboard material 1 ( It is arranged on the left side in FIG. The second fold F2 is a fold F at which the third sheet 23 is folded back toward the other lateral direction (left side in FIG. 1) with respect to the second sheet 22, and one lateral direction (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 (the reference numeral is attached only to the front edge in FIG. 1) of the first end edge E ₁ extending in the lateral direction (direction intersecting the fold F). The ripples) are exposed. Similarly, the second sheet 22 has a second edge E ₂ extending in the lateral direction (the direction intersecting the fold F) (corresponding only to the front edge in FIG. 1 with a reference numeral) of the cardboard. The step 10 is exposed.
In the sheet pair 20 including 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-described 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 cardboard sheet 2 having a higher strength than a material that can be wound into a roll can be made into a compact packing form. The corrugated cardboard material 1 in which the sheet 2 of which strength is ensured is folded is suitable for use as a packaging material of a box making system for manufacturing a box requiring strength.

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

[2. Parameter]
The parameters of the cardboard material 1 will be described below.
First, basic parameters such as the size and the number of steps of the cardboard material 1 will be described. After that, the parameters relating to the sheet 2 of the cardboard material 1 will be described in detail.

[2-1. Basic parameters]
The size of the cardboard material 1 is determined by the following dimensions L1 to L3.
・ Longitudinal dimension L1: Vertical dimension (first dimension)
・ Lateral dimension L2: Lateral dimension (second dimension)
・ Height dimension L3: dimension in the height direction (third dimension)
As the dimensions L1 to L3 are smaller, the size and shape of the box to be manufactured may be more restricted, and as the dimensions are larger, workability such as transportation and delivery may be reduced. 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 cardboard material 1 is N [number], the number of sheets 2 is N + 1 [number]. In this case, N + 1 sheets of sheets 2 are superposed on the cardboard material 1.
For example, as the number of steps of the cardboard material 1, for example, various numbers of steps from 10 to 1000 [steps] can be mentioned. Regarding the corrugated cardboard material for which the parameters related to folding, which will be described in detail later, are measured, it is preferable to measure the parameters at all steps for the measurement objects having a predetermined number of steps (for example, 100 [steps]). On the other hand, for a measurement target having a predetermined number of steps (for example, 100 [steps]) or more, the parameters may be measured partially (for example, a part divided into parts or a set area).

It should be noted that the sheet 2 used for the cardboard material 1 can have an arbitrary basis weight. The range of the grammage used for the sheet 2 is 50 to 1500 [g / m ² ], preferably 100 to 1000 [g / m ² ] and more preferably 200 to 1000 [g / m ² ]. The range is 800 [g / m ² ] and more preferably 200 to 600 [g / m ² ].
The weight of the cardboard material 1 is calculated by multiplying the above-mentioned basis weight by the vertical dimension L1 and the horizontal dimension L2, and the number of stages N + 1 of the sheet 2.

[2-2. Sheet property parameters]
The corrugated cardboard material 1 of the present embodiment has a configuration related to the properties of the seat 2 based on the viewpoint that a good box can be manufactured when it is used as a material for a box making system. Specifically, it has a predetermined configuration regarding the properties of the seat 2 based on at least one of viewpoints I to V listed below.
-Aspect I: Ensuring box-making ability-Aspect II: Suppressing breakage of the folded portion when assembling into a box-Aspect III: Ensuring aptitude when printing is performed-Aspect IV: To prevent the assembled box from breaking (damage) ・ Point of view V: To prevent the liner from peeling off

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.
・ Issue I: Insufficient box-making property ・ Issue II: Fracture and easiness of folding at the time of assembly into a box ・ Issue III: Inadequacy when printed -Problem IV: Tear of assembled box is easy to break-Problem V: Liner is easy to peel off

The predetermined configurations corresponding to the viewpoints I to V and the tasks I to V include at least one of the following configurations a to e.
-Structure a: Structures 1 and 2 below
> Structure 1: Thickness dimension is within a predetermined size range> Structure 2: Plane compressive strength is within a predetermined compressive strength range Structure b: Structures 2 and 3 below
> Configuration 2: Configuration 2 above
> Structure 3: Step repeat ratio is within a predetermined magnification range. Structure c: Angle ratio is within a predetermined ratio range. Structure d: Bursting strength is within a predetermined burst strength range. The adhesive strength is within the specified force range

<Structure a>
As described above, the configuration a includes the “configuration 1 in which the thickness dimension is within a predetermined size range” and the “configuration 2 in which the plane compression strength is within a predetermined compression strength range”.
The “thickness dimension” of the configuration a is a parameter indicating the thickness of each sheet 2. 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 crush resistance of the sheet of measured cardboard material.

The inventors of the present application have found that if the thickness dimension of the sheet 2 is within a predetermined size range and the plane compression strength is within a predetermined compression strength range, the above problems I and II tend to be suppressed. Got Conversely, it has been found that the sheet 2 having a thickness dimension and a plane compressive strength outside the range of the configuration a tends to cause the problems I and II.
That is, the seat 2 is provided with the configuration a based on the viewpoints I and II described above.

If the thickness dimension exceeds the predetermined dimension range, it is presumed that when the sheet 2 is bent along the ruled line for box making, the liners 2a and 2b are not fully extended and are broken, which causes Problem II. On the other hand, if the thickness dimension is below the predetermined dimension range, the strength of the sheet 2 is insufficient and the sheet 2 is likely to be bent at a position other than the ruled line for box making, which causes the problem I. Even when the plane compressive strength is below the predetermined compressive strength range, the strength of the sheet 2 is insufficient, and it is presumed that the sheet 2 is bent at a place other than the ruled line for box making, which causes the problem I. It
If the plane compressive strength exceeds the predetermined compressive strength range, it is presumed that the ruled line for box making is difficult to be formed, 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. Preferably, it is 4.0 [mm] or more and more preferably 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 plane compression strength is within a predetermined compression strength range” as in the configuration a and the above-described “configuration 3 in which the stage take-over ratio is within a predetermined magnification range”.
The “step take-up rate” of the configuration b is a parameter that represents the magnification of the length dimension in the MD direction (transverse direction) with respect to the liner of the core.

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

If the plane compressive strength is below the predetermined compressive strength range, it is presumed that the problem I will be caused due to insufficient strength of the sheet 2 as described above. On the other hand, if the plane compressive strength exceeds the predetermined compressive strength range, it is presumed that the ruled line for box making is difficult to be formed and the problem I is caused.
Similarly, if the step repetition rate is less than the above-mentioned predetermined magnification, it is presumed that the problem I is caused by insufficient strength of the sheet 2. On the other hand, if the step repetition rate exceeds the above-mentioned predetermined magnification, it is presumed that the ruled line for box making is difficult to be formed, and the problem I is caused.

Like the “predetermined compressive strength range” of the configuration a, the “predetermined compressive strength range” of the configuration b is 50 [kPa] or more and 250 [kPa] or less, and is 80 [kPa] or more. It is preferably 220 [kPa] or less, 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 that it is 1.45 [times] or more and 1.55 [times] or less.

  It should be noted that the magnification range of the runout ratio 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 run-out rate of any middle core 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 0.6 [times] or less, more preferably 1.45 [times] or more and 1.55 [times] or less. The double flute run rate here is the run rate calculated for each stage (the stage corresponding to one and the other flute in the double flute).

<Structure c>
As described above, the configuration c has the “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 cardboard material 1.
Hereinafter, the angle ratio will be described with reference to FIG. 2 showing an enlarged main part of the seat 2. Note that FIG. 2 illustrates a state in which the step 10 of the seat 2 is slightly inclined.

The sheet 2 has a structure in which front and back liners 2a and 2b and a core 2c are adhered. The center core 2c constitutes the step 10 and forms a corrugated structure between the liners 2a and 2b.
If the center 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 seat 2, the step 10 formed by the core 2c may be inclined with respect to the ideal shape. The angle ratio represents the degree of such inclination.

This angle ratio is a ratio calculated based on the angles θ1 and θ2 (intersection angles) at which the center 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 centers of the liners 2a and 2b (that is, the middle of the height direction <TD direction>). Is set as.
The angles θ1 and θ2 are acute angles among the intersecting angles at the two adjacent points P1 and P2 in the location where the center core 2c intersects the auxiliary line L.

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 is the angle ratio. This angle ratio is expressed by the following equation c.
Angle ratio = | θ1-θ2 | / (θ1 + θ2) ... Equation c
The angle ratio defined in this way is 0 (zero) for the ideal step 10, and becomes a larger value as the step 10 is biased.

The inventors of the present application have found that the above-mentioned problem III tends to be suppressed when the angle ratio of the sheet 2 is within a predetermined ratio range. Conversely, it has been found that the sheet 2 having the angle ratio outside the range of the configuration c tends to cause the problem III.
That is, the seat 2 is provided with the configuration c based on the viewpoint III described above.
If the angle ratio exceeds the predetermined ratio range, the heights of the steps 10 in the seat 2 are likely to be uneven, and it is conjectured that the problem III is caused.
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 “configuration in which the burst strength is within a predetermined burst strength range” as described above.
The “burst strength” of the configuration d is a parameter corresponding to the withstand load of the sheet 2 in the measured cardboard material 1.
The inventors of the present application have found that the above-mentioned problem IV tends to be suppressed if the burst strength of the sheet 2 is within a predetermined burst strength range. Conversely, it was found that the sheet 2 having a burst strength outside the range of the configuration d tends to cause the task IV.

That is, the seat 2 is provided with the configuration d based on the viewpoint IV described above.
If the burst strength is below the predetermined burst strength range, it is presumed that task IV will be caused due to insufficient load resistance of the sheet 2.
The “predetermined burst strength range” of the constitution d is 500 [kPa] or more, preferably 1000 [kPa] or more, and more preferably 2000 [kPa] or more.

<Structure e>
As described above, the configuration e has the “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 to the liners 2a and 2b.
The "adhesive force" here means the adhesive force between the center core 2c and the front liner 2a (glue machine side adhesive force) and the adhesive force between the center core 2c and the back liner 2b (single facer side adherence). (Force) means the average value.

The inventors of the present application have found that the above 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 seat 2 is provided with the configuration e based on the viewpoint V described above.
If the adhesive force is less than the predetermined force range, it is presumed that the liner 2a, 2b is easily peeled off from the core 2c when the cardboard material 1 is manufactured into a 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]
The cardboard material 1 of the present embodiment is provided with at least one of the configurations a to e described above, so that it is possible to 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 plane compressive strength is within a predetermined compressive strength range, it is possible to secure the box-making property of the measurement cardboard material 1. It is possible to suppress breakage of a bent portion when assembled in a box.
According to the configuration b, the flat compressive strength of the sheet 2 is within a predetermined compressive strength range and the step-up rate is within a predetermined magnification range, so that the box-making property of the measured cardboard material 1 can be ensured. ..
According to the configuration c, since the angular ratio of the sheet 2 is within the 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 burst strength of the sheet 2 is within a predetermined burst strength range, it is possible to suppress breakage of the box assembled from the measurement cardboard material 1.
According to the configuration e, since the adhesive force of the sheet 2 is within the predetermined force range, it is possible to prevent the liners 2a and 2b of the box assembled from the measurement cardboard material 1 from being peeled 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 Examples and Comparative Examples of configurations a to e are described in Item [1], and Examples and Comparative Examples corresponding to 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 Examples and Comparative Examples of configurations a to e, a configuration common to a cardboard material (hereinafter, referred to as “measurement cardboard material”) whose parameters are to be measured will be described.
--Measurement target--
The measurement cardboard material is a double-sided cardboard sheet.
This measurement cardboard material has the following sizes.
・ Size: Vertical dimension 1300 [mm],
Lateral dimension 1150 [mm],
Height dimension 1800 [mm]

--Preprocessing--
The measurement cardboard material or a part thereof whose parameter is to be measured is in a normal state in which it is pretreated for 24 hours or more under the temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%] in accordance with JIS Z0203. Then, each parameter was measured.
In addition, the one-tank type starch paste that is usually used was used as the adhesive for corrugated board that bonds the liner base paper and the core base paper. In addition, the measurement cardboard material was manufactured using a corrugator having a stage roll.
--Evaluation--
Each of the example and the comparative example, which will be described in detail in the next item [2], was evaluated in four grades of “⊚”, “∘”, “Δ”, and “x”.

[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 relating to the configuration a were manufactured using a corrugator having a corrugating roll having a corrugation number of 34 [peaks / 30 cm]. The "number of steps" corresponds to the number of peaks (steps) per 30 [cm] in the sheet, and corresponds to a value obtained by dividing 30 [cm] by the wavelength of the step.

Hereinafter, with respect to Examples a1 to a6 and Comparative Examples a7 to a9, the type of flute, the height of the stage rolls, and the basis weight of the base paper will be described.
In Examples a1 to a6 and Comparative Examples a7 to a9, either one of the single flute and the 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 using a stage roll set to any one stage height among the five types of stage heights as listed below. The "step height" corresponds to the height of the step in the sheet of measured cardboard material, and is a dimension 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 following common liner base papers were used.
・ Liner base paper: 160 [g / m ² ] [MC160: Oji Materia Co., Ltd.]
On the other hand, in Examples a1 to a6 and Comparative Examples a7 to a9, core raw papers having various basis weights prepared according to the manufacturing method disclosed in JP-A-2018-162526 were used. Specifically, for each of Examples a1 to a6 and Comparative Examples a7 to a9, any one of the following five basic weights was adopted. The grammage listed here is the grammage of the base paper which is the material (raw material) of the measured cardboard material.
Basis weight 60 (g / m ² ) (of core raw paper): Comparative example a8
- (a corrugating medium) basis weight 80 [g / m ^2]: Example a6
-Basic weight of core paper 170 [g / m < ² >]: Example a5
Basis weight (of core raw paper) 250 [g / m ² ]: Examples a1 to a4, Comparative example a9
-Basis weight 320 (g / m ² ) of core raw paper: Comparative example a7

Measurement The basis weight of the base paper (liner base paper, core base paper) forming the material of the cardboard material sheet was measured by the following procedures xa to xd.
-Procedure xa: Pretreatment of the base paper whose basis weight is to be measured according to JIS Z0203.
-Procedure xb: Cut out the base paper into a size of 250 [mm] x 400 [mm].
-Procedure xc: The weight of the base paper cut out in procedure xb is measured by an electronic balance.
-Procedure xd: The weight measured in the procedure xc is the weight per square meter [g / m ²
]]

The basis weight of the liner (base paper) forming the sheet of the measured cardboard material is measured by the following steps ya to yf.
-Procedure ya: A sheet of measurement cardboard material is immersed in tap water for 15 [minutes].
-Procedure yb: The liner and the core of the sheet soaked in step ya are peeled off by hand.
-Procedure yc: The liner peeled off in step yb was dried at 105 [° C] for 20 [min].
dry.
-Procedure yd: The liner dried in procedure yc is 250 [mm] x 400 [mm] in size.
Cut out into.
-Procedure ye: The weight of the liner cut out in the procedure yd is measured by an electronic balance.
-Procedure yf: The weight per unit square meter [g / m ²
]]

In addition, the basis weight of the core (base paper) that forms the sheet of measurement cardboard material is measured by the following steps za to zg.
-Procedure za: A sheet of measurement cardboard material is immersed in tap water for 15 [minutes].
-Procedure zb: The liner and the core of the sheet immersed in the procedure za are peeled off by hand.
-Procedure zc: The liner peeled off in procedure zb is dried at 105 [° C] for 20 minutes.
dry.
-Procedure zd: The liner whose basis weight is measured according to JIS Z0203 is pretreated.
-Procedure ze: Cut out the liner into a size of 250 [mm] x 400 [mm]. The wave
If the shape structure remains, cut out into a book size while stretching the wave
You
-Procedure zf: The weight of the liner cut out in procedure ze is measured by an electronic balance.
-Procedure zg: The weight measured in the procedure zf is the weight per square meter [g / m ²
]]

In addition, the basis weight of the liner and core that form the sheet of measured cardboard material to be measured is the same as the basis weight of the base paper that forms the material of the measured cardboard material, even if the same base paper is used as the measurement target. The measured value of may vary by about ± 10%.
The thickness dimension and the plane compressive strength shown in Table 3 below were measured for the above-mentioned measured cardboard materials.

The “thickness dimension” is a parameter corresponding to the thickness of each sheet in the measured cardboard material. This thickness dimension was measured by the following procedures aa to ad.
・ Procedure aa: Half of the total number of corrugated cardboard materials (that is, the middle step)
Collect the upper and lower five-tiered sheets as standard. In addition, when collecting the test piece
, Be careful not to collapse the steps.
-Procedure ab: 5 [cm] x 5 [cm] size from the ten sheets collected in procedure aa
Cut a test piece into a square.
-Procedure ac: Measure the thickness of the test piece cut out in procedure ab with the following compliant standards, measuring equipment, and
Measure under constant conditions.
＞ Compliance standard: Corrugated board industry standard T0004: 2000
＞ Measuring equipment: Thickness gauge (Mitutoyo Ratchet, model number K470101K)
> Measurement conditions: Plunger diameter 16 [mm], load 3923 [mN]
・ Procedure ad: From the thickness measured in procedure ac, a disturbance (required) that reduces the accuracy of the measurement result.
Factor) that can be a factor (so-called large deviation)
What was taken was taken as the thickness dimension.
Note that, in the “exclusion of numerical values that may be a disturbance” of the procedure ad, when each numerical value measured in the procedure ac is used as a population, numerical values whose standard deviation of the population deviates from ± 3σ are excluded.

The “planar compressive strength” is a parameter corresponding to the crush resistance of the measured cardboard material sheet. This plane compressive strength was measured by the following procedures aA to aD.
-Procedure aA: Similar to procedure aa, the standard is half of the total number of measured corrugated cardboard materials
Collect the upper and lower five-stage sheets.
-Procedure aB: A circular sample with a diameter of 6.4 cm from the ten sheets collected in procedure aA.
Cut out the test piece.
・ Procedure aC: Plane compressive strength of the test piece cut out in procedure aB is measured according to the following standard.
Measure under the conditions of equipment, test speed and parallelism. Note that parallelism means flatness.
It represents the degree of parallelism of the jig for surface compression.
> Standards: JIS Z 0403-1
＞ Measurement equipment: Compression with a jig for plane compression (made by Tester Sangyo Co., Ltd.)
Testing machine (RTF1350, manufactured by A & D Co., Ltd.)
> Test speed (measurement condition): 12.5 ± 2.5 [m / min]
> Parallelism (measurement condition): 1/1000 or less of compression dimension-Procedure aD: Similar to the procedure ad above, measured from the plane compression strength measured in procedure aC.
Exclude numerical values that may be disturbances (factors) that reduce the accuracy of the fixed results,
The average value was taken as the plane compressive strength.

--Evaluation--
With respect to Examples a1 to a6 and Comparative Examples a7 to a9 in which the thickness dimension and the plane compression strength were respectively measured as described above, the box-forming property and ruled cracks described below were evaluated.
The "box-making property" refers to the accuracy of a box in which a cardboard piece (hereinafter referred to as an "evaluation cardboard piece") cut out by a cut line that crosses the folds of the measurement cardboard material is manually assembled (handmade). It is a corresponding evaluation standard. As a method of hand-assembling, the cut corrugated cardboard pieces were folded at predetermined ruled line portions, adhered with a hot-melt adhesive, and made into boxes.
The method of assembling the evaluation cardboard pieces by the box making system is the same whether manually or by the box making system. Therefore, it can be said that the box-making property of the evaluation cardboard piece assembled by hand is correlated 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 was punched out in the following shapes and sizes with a sample cutter (CF2-1218 manufactured by Mimaki Engineering Co., Ltd.) in the following number.
-Shape: Pattern in which the A-type cardboard box is developed-Size: Width of the side plate of the A-type cardboard box 356 [mm],
The width of the end plate of the A-type cardboard box is 159 mm,
Height of type A cardboard box 256 [mm]
・ Number of sheets: 100 [sheets]

The above evaluation cardboard pieces were evaluated according to the following criteria.
∘: All (100 [sheets]) evaluated cardboard pieces have good box-making properties.
◯: Out of 100 [sheets] of corrugated cardboard pieces, 1 to 2 [sheets] have poor box-making properties.
-[Delta]: 3 [sheets] out of 100 [sheets] of corrugated cardboard pieces have poor box-making properties.
*: Out of the evaluation cardboard pieces of 100 [sheets], 4 [sheets] or more have a poor box-making property.
In addition, in Example a4 in which the box-making property was evaluated as “◯”, the box-making property of 2 [sheets] was poor.

Here, "good box-making property" means that the distance dimension between the following folded portions A and B in the evaluation cardboard piece is less than the predetermined distance dimension.
-Folded part A: a part where ruled lines (elements different from folds) for box making are provided-folded part B: part that is actually folded when assembled in a box (during box making) The "dimension" is 2.0 [mm] for the dimension in the direction perpendicular to the folds of the evaluation cardboard piece (MD direction) and 5 [mm] for the dimension in the direction parallel to the folds (CD direction). ].
On the other hand, "poor box formability" means that the distance dimension between the folded portions A and B in the evaluation cardboard piece is equal to or greater than the predetermined distance dimension.

In addition, "ruled crack" means that the bent portion is broken when the evaluation cardboard piece is assembled into a box. This crease crack is observed by visually observing a box whose box-forming property is evaluated (that is, a box in which evaluation cardboard pieces are assembled, hereinafter referred to as "evaluation box").
This ruled crack was evaluated according to the following criteria.
⊚: No creases were found in all (100 [boxes]) evaluation boxes.
◯: Cracks were found in 1 to 2 [boxes] of 100 [boxes] evaluation boxes.
-△: A crack was found in 3 [boxes] of 100 [boxes] evaluation boxes.
*: Ruled cracks were found in 4 or more boxes out of 100 [boxes] evaluation boxes.
In addition, regarding Example a3, a5, a6 and Comparative Example a8 which were evaluated as “◯” regarding ruled cracks, 1 [box] in Example a3, a5, a6 showed the ruled cracks, and Comparative Example a8 There was a crack on 2 [box].

In Examples a1 to a6, the thickness dimension is 2.0 [mm] or more and 9.6 [mm] or less, and the plane compressive strength is 50 [kPa] or more and 250 [kPa] or less. A good evaluation of “Δ” or more was obtained in both box-making property and crease 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 plane compressive strength outside the range of 50 to 250 [kPa], A poor evaluation was obtained in which the box-making property was evaluated as "x". Further, in Comparative Example a7 having a thickness dimension larger than 9.6 [mm], the evaluation of ruled cracks was also a poor evaluation of “x”.

According to Comparative Example a7, when the thickness dimension is larger than 9.6 [mm], the liner base paper is not fully extended and is broken when folded by the box-making ruled line, resulting in a poor evaluation of ruled cracks. Inferred.
From this comparative example a7, when the plane compressive strength is larger than 250 [kPa], it becomes difficult to insert a ruled line for box making (because the formability of the ruled line is deteriorated), and a portion other than the ruled line for box making is formed. It is also presumed that the product will be bent at and the box-making property will be poorly evaluated.

From Comparative Example a8, when the plane compressive strength is less than 50 [kPa], the bending strength of the evaluation cardboard piece is insufficient, and the corrugated board is apt to be bent at a place other than the ruled line for box making. 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 evaluation cardboard piece is insufficient, and the evaluation cardboard piece is easily bent at a place other than the ruled line for box making. It is presumed that the evaluation of box properties will be poor.

In view of the above Comparative Examples a7 to a9, from Examples a1 to a6, it is inferred that the smaller the thickness dimension in the range of 9.6 [mm] or less, the more the occurrence of ruled cracks 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 a place other than the ruled line for box making is suppressed.
From Examples a1 to a6, it can be inferred that when the plane compressive strength is 250 [kPa] or less, the defects of the ruled lines formed for box making can be suppressed. On the other hand, if the plane compressive strength is 50 [kPa] or more, it is presumed that the bending strength of the evaluation cardboard piece is ensured 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 plane compressive strength is 50 [kPa] or more and 250 [kPa] or less, box-making property It can be said that it is possible to achieve both the securing of the cracks and the suppression of the ruled cracks.

<Structure b>
--Measurement target--
The same liner base paper as in Examples a1 to a6 and Comparative examples a7 to a9 was used as the measurement cardboard material used in Examples b1 to b3 and Comparative Examples b4 and b5 relating to the configuration b, and the following core raw paper was used.
・ Core raw paper: 170 [g / m ² ] [LB170: Oji Materia Co., Ltd.]
In addition, the measurement cardboard materials used in Examples b1 to b3 and Comparative Examples b4 and b5 were manufactured using a corrugator having roll rolls with various roll rates shown in Table 4 below. Further, with respect to each of Examples b1 to b3 and Comparative Examples b4 and b5, the plane compressive strength was measured by the same procedure as the procedure aA to aD described above, and the plane compressive strength shown in Table 4 below was measured. ..

The "step take-up rate" is a parameter corresponding to the magnification of the length dimension in the MD direction with respect to the core liner. This step repetition rate was measured by the following procedures ba to bg.
-Procedure ba: Similar to the procedures aa and aA, half of the total number of corrugated cardboard materials to be measured
Based on the above, collect the upper and lower five sheets.
-Procedure bb: The direction in which the core ridges are continuous from the ten sheets collected in procedure ba (horizontal direction)
Direction, MD direction) is 20 [cm] and is perpendicular to the center core mountain (vertical direction).
Direction, CD direction) to a size of 10 [cm].
-Procedure bc: The test piece cut out in procedure bb is immersed in tap water for 24 hours.
-Procedure bd: After the immersion of 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 that has been taken out in Procedure bd and stretched by hand
Is measured with a ruler.
-Procedure bf: "Expanded length of core" measured in procedure be and cut out in procedure bb
The length in the direction in which the core piles of the
The length of the step is 20 [cm] here, and
To calculate.
Corrugation rate = length of fully extended core / length of original cardboard sheet ... Formula b
-Procedure bg: Similar to the procedures ad and aD above, measurement is performed from the stage repeat rate calculated in procedure bf.
Exclude numerical values that may be disturbances (factors) that reduce the accuracy of the fixed results,
The average value was taken as the step repetition rate.

--Evaluation--
The box-making properties of the examples b1 to b3 and the comparative examples b4 and b5 for which the step repetition rate was obtained as described above were evaluated. This box-making property is synonymous with the box-making property used for the evaluation of Examples a1 to a6 and Comparative Examples a7 to a9. In addition, in Example b1 in which the box-making property was evaluated as “◯”, the box-making property of 2 [sheets] was poor.

In Examples b1 to b3, the step repetition rate is 1.2 [times] or more and 1.7 [times] or less, and the plane compressive strength is 50 [kPa] or more and 250 [kPa] or less. Therefore, a good evaluation of at least “Δ” was obtained for the box-making property.
On the other hand, Comparative Example b4 in which the step yield rate is less than 1.2 [times] and the plane compressive strength is less than 50 [kPa], and the plane compressive strength is greater than 1.7 [times] and the plane compressive strength is higher. In Comparative Example b5 having a value of more than 250 [kPa], the box-making property was evaluated as "x", which was a poor evaluation.

From Comparative Example b4, since the plate rolling rate is less than 1.2 [times] and the plane compressive strength is less than 50 [kPa], the bending strength of the evaluation corrugated cardboard piece is insufficient, so that the box is manufactured. It is presumed that it becomes easy to bend at a place other than the ruled line for the box, and the evaluation of the box-making property becomes poor.
From Comparative Example b5, it is difficult to insert the ruled line for box making (the formation of the ruled line) because the run-out rate is greater than 1.7 [times] and the plane compression strength is greater than 250 [kPa]. It is presumed that the evaluation of the box-making property becomes poor because the sheet is bent at a place other than the ruled line for box-making because of the deterioration of the box-forming property).

In view of Comparative Examples b4 and b5 described above, from Examples b1 to a3, since the step repetition rate is 1.2 [times] or more and the plane compressive strength is 50 [kPa] or more, It is presumed that bending at locations other than the ruled lines for boxes can be suppressed. In addition, it is presumed that the line-ratio of 1.7 [times] or less and the plane compressive strength of 250 [kPa] or less can suppress defects in ruled lines formed for box making.
Therefore, if the step yield rate is 1.2 [times] or more and 1.7 [times] or less and the plane compressive strength is 50 [kPa] or more and 250 [kPa] or less, box making It can be said that the sex can be secured.

<Structure c>
--Measurement target--
In Examples c1 to c3 and Comparative Example c4 relating to the configuration c, the same base paper as in Examples b1 to b3 and Comparative Example b4 was used, and A was manufactured using a corrugator having a stage roll having the following specifications. Measurement of flute Cardboard material was used.
・ Step height: 4.5 [mm]
・ Number of steps: 34 [mountain / 30 cm]
Then, the measured cardboard materials manufactured to have the angle ratios shown in Table 5 below were used for 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 measured cardboard material. This angle ratio was measured by the following procedures ca to cf.
-Procedure ca: In the sheet of measurement corrugated cardboard, one crest of the core is longitudinally (CD direction).
Take a photo from.
・ Procedure cb: The height of one mountain in the photograph taken in procedure ca is 10 cm or more.
And print it on the printing paper.
-Procedure cc: a direction parallel to the front and back liners (that is, the lateral direction <MD direction>),
Draw an auxiliary line through the center (TD direction center) between the front and back liners.
-Procedure cd: Among the intersections of the auxiliary line drawn in step cc and the core, two adjacent arbitrary points
select.
-Procedure ce: At each of the two points selected in the 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.

--Evaluation--
The printability was evaluated for Examples c1 to c3 and Comparative Example c4 in which the angle ratio was obtained as described above.
The "printability" is an aptitude when printing is performed on the measurement cardboard material, and is an evaluation standard corresponding to the quality of the printing performed on the measurement cardboard material.
This printability was evaluated by the following procedures cA to cC.
-Procedure cA: A sheet of measurement corrugated cardboard is sized at 500 [mm] x 1350 [mm].
Cut into small pieces.
-Procedure cB: Direct flexographic printing machine D for the test piece cut in procedure cA
550 [line / in by YNA FLEX160 (manufactured by Bobst)
Water-based flexo ink (Sakataine
(Manufactured by KU) and coated and printed in the following order.
> Order of coating: Red, ink, indigo, yellow, varnish. Step cC: The finish printed in step cB was visually observed.

The above printability was evaluated according to the following criteria.
⊚: There is no unevenness of ink inking and the printing finish is good.
-○: Almost no unevenness of ink inking and no practical problems.
・ △: Ink unevenness is slightly large, but there is no problem in practical use.
X: Ink unevenness is very large, there are practical problems, and the quality is significantly poor.

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

From Comparative Example c4, it is estimated that the angle ratio is larger than 0.30 and the heights of the steps are not uniform, so that the printability is evaluated poorly. 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 inked is also one of the reasons why the evaluation of printability is inferior.
On the other hand, it is presumed from Examples c1 to c3 that the angle ratio of 0.30 or less suppresses the variation in the height of the step and obtains printability without any practical problems. From the examples c1 and c2, the variation in the height of the step can be reliably suppressed by the angle ratio being 0.15 or less, and from the example c1 by the angle ratio being 0.05 or less, It is estimated that it will be further suppressed.
Therefore, it can be said that printability can be ensured if the angle ratio is 0.30 or less.

<Structure d>
--Measurement target--
For the examples d1 to d3 and the comparative example d4 relating to the structure d, the same core raw papers as the examples b1 to b3, c1 to c3 and the comparative examples b4 and c4 were used. On the other hand, in Examples d1 to d3 and Comparative Example d4, liner base papers having various basis weights prepared according to the method for producing a liner for cardboard disclosed in Japanese Patent No. 6213364 were used. Specifically, for each of Examples d1 to d3 and Comparative Example d4, one of the following four types of basis weight was adopted.
-Basis weight (of liner raw paper) 90 [g / m ² ]: Example d1
-Basis weight 170 (g / m < ² >) (of liner base paper): Example d2
- (liner base paper) having a basis weight 250 [g / m ^2]: Example d3
Basis weight 60 (g / m ² ) (of liner base paper): Comparative example d4
In addition, a measurement cardboard material manufactured by using a corrugator having the same rolls as in Examples c1 to c3 and Comparative Example c4 was used.
The burst strength was measured for each of Examples d1 to d3 and Comparative Example d4 using the measurement corrugated cardboard material manufactured as described above, and the burst strength shown in Table 6 below was measured.

The “burst strength” is a parameter corresponding to the easiness of tearing of the evaluation box (IFC code: 0401) that is the target of evaluation of ruled cracks in the configuration a described above. The burst strength was measured by the following procedures da to dd.
・ Procedure da: Similar to procedure aa, the standard is half of the total number of corrugated cardboard materials.
Collect the upper and lower five-stage sheets.
-Procedure db: 100 [mm] x 100 [mm from the ten sheets collected in procedure da
] Cut a test piece into a square of size.
-Procedure dc: The thickness of the test piece cut out in the procedure db is measured according to the following standard, test piece, and thickness.
Measure with the equipment and measurement conditions.
＞ Compliance standard: JIS P 8131 (Paperboard-rupture strength test method)
> Measurement equipment: Toyo Seiki Co., Ltd., Murren burst tester EH
> Measurement condition: The pressure when expanded to a height of 10 [mm] from the tightening surface is 1
70-220 [kpa] rubber septum is used. Procedure dd: Similar to procedures ad, aD, and aC, from the burst strength measured in procedure dc,
Exclude values that can be disturbances (factors) that reduce the accuracy of measurement results,
The average value was taken as the burst strength.

--Evaluation--
With respect to Examples d1 to d3 and Comparative Example d4, the burst strength of which was obtained as described above, the breakability of the evaluation box was evaluated.
"Easy to break" is an evaluation standard corresponding to the weight of the load capacity of the contents stored in the box. This fragility was evaluated by the following procedures dA to dC.
・ Procedure dA: Weight is adjusted so that the weight per unit area is 15 [kgf / cm ² ].
Store in the evaluation box. The evaluation box is an assembly type (
IFC code 0401).
-Procedure dB: After procedure dA, two workers hold the bottom surface where the weight is not in contact with the evaluation box.
Lift up and hold for 30 seconds.
-Procedure dC: It is visually confirmed whether or not the evaluation box is broken in procedure dB.

The easiness of tearing was evaluated according to the following criteria.
⊚: The appearance of the evaluation box does not change after being lifted.
-○: The evaluation box is slightly broken after being lifted, but the weight remains in the evaluation box.
-: The evaluation box is torn after lifting, but the weight stays in the evaluation box.
・ ×: The evaluation box is severely broken after being lifted, and the weight falls from the evaluation box.

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

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

<Structure e>
--Measurement target--
For the examples e1 to e3 and the comparative example e4 relating to the structure e, the same base papers as the examples b1 to b3, c1 to c3, d1 to d3 and the comparative examples b4, c4 and d4 are used, and the examples c1 to c3 and d1 are used. .About.d3 and A corrugators having the same roll rolls as Comparative Examples c4 and d4 were used.
The adhesive force was measured for each of Examples e1 to e3 and Comparative Example e4 using the measurement corrugated board material manufactured as described above, and the adhesive force shown in Table 7 below was measured.
Regarding the notation in Table 7, "S side" means "single facer side" (back liner side), and "G side" means "glue machine side" (front liner side).

The “adhesive force” is a parameter corresponding to the peeling resistance value of the bonded portion between the liner and the top of the core (the portion corresponding to the maximum value) in the sheet of measured cardboard material. To put it plainly, it is a parameter that corresponds to the difficulty of peeling of the liner that forms the sheet of cardboard material.
This adhesive force was measured by the following procedures ea to ed.
・ Procedure ea: See the top and bottom 10 steps based on half of the total number of measured corrugated board materials.
Tissue is collected and 20 sheets without deformation (for example, dents) are cut out.
-Procedure eb: From the sheet cut out in procedure ea, the size of the test sun is reduced to the size shown below.
Cut out the pull with a cutter.
Direction parallel to the corrugated structure of the core (vertical direction <CD direction>): 50 [mm]
Direction orthogonal to the corrugated structure of the core (lateral direction <MD direction>): 85 [mm]
-Procedure ec: Prepare 10 sheets of each of the front and back samples cut out in the procedure eb. Ingredient
Physically, ten sheets for measuring the adhesive force on the single facer side, and
-Prepare ten sheets for measuring the adhesive force on the machine side.
-Procedure ed: The sample prepared in the dot order ec is mounted on the following measuring device, and the following compliance is applied.
The adhesive strength was measured under the standard and measurement conditions.
> Standards: JIS Z0402
> Measuring device: compression tester (RTF1350, manufactured by A & D Co., Ltd.)
＞ Measurement condition: Pin attachment (Japan TMC Co., Ltd.) is attached to the sample
Then, place it on the measuring device and set the peeling surface to the upper side at 13 [mm / min.
] The maximum load when the load is applied at the speed of
Measure the weight.
-Procedure ed: Adhesion force measured in procedure ed as in procedures ad, aD, aC, and dd.
Exclude values that may 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 the examples e1 to e3 and the comparative example e4 in which the adhesive force was obtained as described above.
“Peeling off the liner” is an evaluation standard that corresponds to the quality of the box and the quality of the appearance. This liner peeling was evaluated by the following procedures eA to eC.
-Procedure eA: Similar to the evaluation of the box-forming property according to the configurations a and b, straddling the fold of the measured cardboard material.
Cut out the evaluation cardboard piece with the cut line. In addition, the first evaluation
When cutting out a ball piece, replace it with a new cutter blade.
Was used without replacement until the 100th sheet (last).
-Procedure eB: Assemble the evaluation cardboard pieces cut out in Procedure eA by hand.
-Procedure eC: Removal of the liner (sheet) in the evaluation box assembled in procedure eB
Observe the presence or absence.

The liner peeling was evaluated according to the following criteria.
∘: No peeling of the liner was observed in all (100 [boxes]) evaluation boxes.
◯: Peeling of the liner was observed in 1 to 2 [boxes] of 100 [boxes] evaluation boxes.
-: Peeling of the liner was observed in 3 to 4 [boxes] of the 100 [boxes] evaluation boxes.
*: The liner was peeled off in 5 [boxes] of 100 [boxes] evaluation boxes.
Regarding Examples e2 and e3 in which "○" was obtained for the liner peeling, peeling of the liner was observed in 1 [box] in Example e2 and 2 [box] in Comparative Example e3. It was observed. In addition, there was no example or comparative example in which the evaluation of “Δ” was obtained for the 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”) was 140 [N] or more, and liner peeling was “◯”. The above evaluations were obtained. In particular, in Example e1 having an average adhesive force of 220 [N] or more, a rating of “⊚” was obtained.
On the other hand, in Comparative Example 1 in which the average adhesive force was less than 140 [N], the liner peeling was evaluated as “x”.

If the average adhesive force is 140 [N] or more, the liner becomes difficult to peel off when the evaluation cardboard piece is cut out from the measurement cardboard material, and the liner does not easily separate when the evaluation box is assembled from the evaluation cardboard piece. Inferred. Furthermore, if the average adhesive force is 220 [N] or more, it is presumed that the peeling of the liner can be prevented both when the evaluation cardboard piece is cut out and when it is assembled. Therefore, the average adhesive force is 140 [N]. If it is above, it can be said that the liner of the evaluation box is hard to peel off. Furthermore, it can be said that deterioration of the appearance of the evaluation box can be suppressed and the quality of the evaluation box can be ensured.

[3. Example combining three configurations]
Finally, an example cde in which the configurations c, d and e are combined will be described.
The details of the measurement target and the evaluation of Example cde are the same as those described above, unless otherwise specified.
--Measurement target--
Example cde was evaluated for the measured cardboard material that also had the parameters listed below.
・ Angle ratio: 0.00
・ Rupture strength: 2009 [kpa]
-Average adhesive force: 237.5 [N]
> Single facer side: 230 [N]
> Glue machine side: 245 [N]

--Evaluation--
The printability, fragility, and liner peeling were evaluated for the cardboard material of Example cde. As a result, excellent evaluation (“A” above) was obtained in any of printability, fragility, and liner peeling.
From the evaluation results of the example cde, it is understood that when the configurations c, d, and e are combined, the evaluations corresponding to the respective configurations c, d, and e are not impaired and are excellent.

Furthermore, when the measured cardboard material having the above parameters is used in the box making system, it is presumed that it is possible to achieve both reduction of the amount of glue that adheres the liner and the core and suppression of peeling of the liner. From the reduction of the amount of glue used, it is presumed that the weight of the manufactured box can be reduced. The reasons are as follows.
・ Reason α: Temporary step heights are not uniform (angle ratio is large, printability is not good)
) Is low in order to securely bond the liner to the core at all steps.
It is necessary to bond the liner and the core with a thick layer of glue that is suitable for each step.
While a large amount of glue is used in this way, the printability in Example cde
As the excellent evaluation of
It is presumed that the use amount of will be suppressed.
・ Reason β: If the amount of glue used is suppressed when the height of the steps is not uniform, the glue usage
Although the dose can be suppressed, the liner may peel off at the location corresponding to the lower step.
There is a risk of damage. On the other hand, in Example cde, the printability was excellent.
Since the evaluation can be obtained, the variation in the step height can be suppressed, and the amount of glue used
Even if it is suppressed, peeling of the liner can be suppressed.

[III. Modification]
The above-described embodiment is merely an example, and is not intended to exclude various modifications and application of techniques that are not explicitly shown in this embodiment. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. In addition, they can be selected as necessary and can be appropriately combined.

1 Cardboard material 10th stage (wavy)
2 sheet 20 sheet pair 21 first sheet 22 second sheet 23 third sheet F fold L auxiliary line L1 vertical dimension (first dimension)
L2 horizontal dimension (second dimension)
L3 height dimension (third dimension)

Claims (6)

In a continuous corrugated cardboard, a rectangular sheet is folded back in a second direction orthogonal to the first direction on a plane along the fold at each of the folds extending linearly along the first direction, Ri cardboard materials der folding bellows the sheet are stacked along a third direction perpendicular to both the direction and the second direction,
The cardboard material is used for an automatic packaging system that automatically manufactures a box,
The sheet is
According to JIS Z0203, in a normal state where pretreatment is performed for 24 hours or more under temperature and humidity conditions of temperature 23 [° C.] and humidity 50 [%],
At two locations where the core intersects and is adjacent to a virtual auxiliary line extending in the second direction in the center of the front liner and the back liner when viewed from the first direction, the center line and the auxiliary line The cardboard, which satisfies the condition that the ratio of the difference between the two acute angles formed by is divided by the sum of the two acute angles is 0.30 or less (excluding 0.08 or less). Material. The cardboard material according to claim 1, wherein the sheet has a burst strength measured according to JIS P8131 of 500 [kPa] or more. The cardboard material according to claim 1 or 2, wherein the sheet has an average adhesion value of 140 [N] or more measured on the single facer side and the glue machine side according to JIS Z0402. . The thickness of the sheet is 2.0 [mm] or more and 9.6 [mm] or less as measured according to the corrugated board industry standard T0004: 2000. The cardboard material according to any one of items. The sheet is
The stage repeat rate is 1.2 [times] or more and 1.7 [times] or less,
The flat compressive strength measured according to JIS Z0403-1 is 50 [kPa] or more and 250 [kPa] or less, and the cardboard according to any one of claims 1 to 4. Material. A cardboard box using the cardboard material according to any one of claims 1 to 5.

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