JP2002052630A - Single facer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of dry streaks in a corrugated board with a small corrugation height, especially a corrugated board with 1.2 mm or less flute height of the E-flute E or under, with regard to a single facer. SOLUTION: The groove width W of suction grooves 20 formed in the surface of a corrugating roll 1 is set within the range of 0.5-1.4 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugator for producing a low corrugated cardboard used for a box for gift items, a box for packing food such as pizza, and a general paper box, that is, a microflute corrugated cardboard. It relates to a step forming device (single facer).

[0002]

2. Description of the Related Art Corrugated cardboard (corrugated cardboard sheet) is lightweight and can be reused, and thus has been used for various packaging materials such as outer boxes since ancient times. According to the JIS standard, cardboard is A according to the number of steps per unit length.
It is divided into stages, B stages, and C stages. Further, although not specified in the standard, there is a corrugated cardboard called an E-stage having a larger number of stages per unit length. Each of these corrugated boards has a different corrugated height (corrugated core corrugated height), which is not a standard, but is generally 5 mm for A and 3 mm for B.
mm, about 3.6 mm in the C-stage, and about 1.2 mm in the E-stage. Among them, the cardboard of the E-stage has the same use as the thick paperboard, and is used, for example, for gift boxes. Moreover, it may be laminated with a high corrugated height and used as a double-sided corrugated cardboard sheet.

In recent years, cardboard boxes having a greater number of steps per unit length than the E steps and a lower step height have been used. These corrugated boards are referred to as F-tier, mini-corrugated board, G-tier, N-tier, etc. in order of decreasing step height. These low corrugated cardboards are also called micro flutes and are also used as heat insulating wall materials for cup ramen containers and the like. Utility model registration No. 2533661 is an example.

[0004] The corrugated cardboard sheet is manufactured by a device called a corrugator. The corrugator is equipped with a single facer and a double facer, and usually a single facer is used to form a single-faced cardboard consisting of a core and a back liner base paper, and then a double facer is used to make the other front side liner base paper one side The corrugated paperboard is bonded to corrugated paperboard to form a corrugated paperboard sheet. Among them, the single facer is mainly composed of an upper roll, a lower roll, a press roll (or a belt press device), and a glue roll. The step forming of the core and the back liner base paper on one side of the step-formed core are formed. And bonding.

In a single facer, if a step-formed core is lifted from a step roll by centrifugal force, a so-called "fluff-out phenomenon" occurs, and the gluing amount, the step height, the number of steps, and the like fluctuate. I will. Therefore, in order to prevent the core from floating from the step roll, a method of holding the core with an arcuate metal plate called a finger plate has been adopted in the past. However, in the finger method, there are various problems such as that the core does not completely adhere to the corrugated roll, the finger is worn, and adjustment is required to be skillful. Is becoming more common.

The fingerless system generally includes a pressure system and a suction system. In the pressurization method, the core is brought into close contact with the step roll by setting the periphery of the step roll in a pressurized state.
On the other hand, in the suction method, grooves (suction grooves) having a width of about 1.6 mm to 3 mm are circumferentially cut at regular intervals along the axial direction of the step roll, and holes for sucking air are provided at the bottoms of the suction grooves. And a mechanism for adhering the core to the step roll by sucking air from the hole. At present, this suction method is the mainstream of single facers.

[0007]

However, in the above-mentioned suction system, since the suction force due to the negative pressure acts on the core from the suction groove, the portion of the core on the suction groove is drawn into the suction groove. A dent in the thickness direction occurs.
For this reason, when glue is applied to the top of the core by the glue roll, a non-contact portion with the glue roll is formed. Since the pressing force at the time of joining the core and the liner is also insufficient, the adhesive strength is reduced and the strength as a corrugated cardboard is reduced.

[0008] This phenomenon can be confirmed by observing the single-faced cardboard after leaving the single facer by peeling the core and the liner. In particular, by checking the adhesion state of the starch paste by a reaction with an iodine solution (iodine reaction) after peeling off the adhesive surface with water, a portion where the paste is small is streaked in a direction perpendicular to the paste line as shown in FIG. Is clearly observed. This phenomenon that glue does not adhere is called “dry streak” from the mainstream stage of the finger type step forming apparatus.

When forming a cardboard box or the like using corrugated cardboard, a ruled line is preliminarily formed at a bent portion. If there is a dry streak portion near the ruled line portion, the ruled line portion and the dry streak portion are formed. In some cases, a problem may occur depending on the relationship between the strength and the strength. First, in cardboard having a step height higher than the step E, the basis weight of the core is usually 100 g /
rigidity of There is also a cardboard itself to exceed m ² is high. For this reason, there is a large difference in strength between the ruled line portion and the dry streak portion during the processing of the paper container, and a problem such as bending at the dry streak portion instead of the ruled line portion is unlikely to occur, and dry streak does not cause much problem.

However, in the case of a corrugated board having a small corrugated height of E or less (corresponding to a corrugated height of 1.2 mm or less), the rigidity of the corrugated cardboard itself is low. It is small and may be bent at the dry streak portion instead of the ruled line portion at the time of bending. In particular, when a box is manufactured at a high speed, such a problem is highly likely to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to reduce the occurrence of dry streaks in a corrugated cardboard having a low corrugated height, particularly a corrugated cardboard having a corrugated height of 1.2 mm or less. The purpose is to provide a single facer.

[0012]

In order to achieve the above object, a single facer according to the present invention includes a step roll having a plurality of steps provided on a surface thereof. In a single facer of a corrugator for forming a corrugated board of 2 mm or less, a plurality of suction grooves extending in the circumferential direction of the corrugated roll on the surface of the corrugated roll, that is, a suction action of sucking air toward the inside of the corrugated roll. A plurality of grooves having the following shape are provided along the axial direction of the step roll, and the width of the suction grooves is set within a range of 0.5 mm or more and 1.4 mm or less. The width of the suction groove is 0.5 mm.
It is more preferable to set the distance in the range of 1.1 mm or less, and by setting the distance in this range, it is possible to further reduce the occurrence of dry streak.

The single facer has a hole (suction hole) extending parallel to the axial direction in the cylindrical portion of the step roll.
A plurality of holes are formed at equal intervals in the circumferential direction, the suction hole communicates with the suction groove inside the roll, and air is sucked from the suction hole opened at the end of the roll, more preferably. The suction start position by the suction hole is a rotation angle of the step roll within a range of 5 degrees to 23 degrees from a position where the step roll is engaged with another step roll facing the downstream side in the rotation direction of the step roll. To the position shifted toward. By adjusting the timing of starting the suction in this way, it is possible to further enhance the effects of the present invention.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a single facer as one embodiment of the present invention.
In the present embodiment, the present invention is applied to a single facer of a corrugator for manufacturing a cardboard having a low step height of E or less, specifically, a cardboard having a step height in a range of 0.4 to 1.2 mm. ing. The corrugated cardboard having a corrugated height in the range of 0.4 to 1.2 mm is generally a corrugated cardboard having 90 to 170 corrugations per 30 cm. In other words, a corrugated cardboard having a corrugated height in the range of 0.4 to 1.2 mm can be said to be a corrugated cardboard having a low corrugated height of E or less (corresponding to a corrugated height of about 1.2 mm).

The reason why a single facer for manufacturing a cardboard having a step height exceeding 1.2 mm is excluded is as follows. That is, for corrugated cardboard having a corrugated height of more than 1.2 mm (having a corrugated height higher than that of the corrugated cardboard of E)
Even if a step roll having a wide suction groove width (a step roll having a groove width of 1.6 to 3 mm) is used, dry streak is less likely to occur, and even if dry streak occurs, the rigidity of the cardboard itself is reduced. This is because, when the paper container is processed, a trouble such as bending at a dry streak portion hardly occurs.

In addition, as for a single facer for manufacturing a cardboard having a corrugated height of less than 0.4 mm, the presently manufactured corrugated cardboard has a minimum corrugated height of 0.4 mm. Excluded from form. However, when it becomes necessary to produce a cardboard having a corrugated height of less than 0.4 mm, the present invention can of course be applied to a single facer for producing the cardboard.

First, the overall configuration of the present single facer will be described with reference to FIG. As shown in FIG. 1, the present single facer includes an upper roll (step roll) 1 having a corrugated step formed on the outer peripheral surface, and a lower roll 2 also having a corrugated step formed on the outer peripheral surface. . The upper roll 1 and the lower roll 2 are disposed to face each other in the up-down direction, and rotate synchronously while meshing their respective corrugated steps via the center core 4.

The core 4 is supplied from a core supply device (not shown) to a meshing portion between the upper roll 1 and the lower roll 2. Then, a corrugated step is formed by being stepped at the meshing portion. The upper roll 1 is located on the downstream side in the conveying direction of the core 4 with respect to the meshing portion of the upper roll 1 and the lower roll 2.
A glue roll 7 is disposed diagonally below (at a position approximately 45 degrees downstream from the meshing portion between the upper roll 1 and the lower roll 2 in the rotational direction of the upper roll 1). The core 4 in which the step is formed at the meshing portion between the upper roll 1 and the lower roll 2 is
While being conveyed while being held by the corrugated step portion of the upper roll 1, the paste 8 is applied to the top of the step by the paste roll 7 on the way. The glued core 4 continues to be in the upper roll 1
Is transported toward the portion to be bonded to the upper liner 5 while being held.

Above the upper roll 1, a belt roll 1 is provided.
The pressure belt 9 wound around 0 a and 10 b is disposed so as to be pressed against the upper roll 1 via the liner 5. The liner 5 is supplied between the pressure belt 9 and the upper roll 1 from left to right in FIG. The pressure belt 9 is driven to rotate at substantially the same speed as the traveling speed of the liner 5 by the rotation of the belt rolls 10a and 10b.
Is pressed against the upper roll 1 together with the core 4, and the liner 5 is bonded to the core 4.

Next, the structure of the upper roll 1 which is a main part of the present single facer will be described with reference to FIGS. As shown in FIGS. 1 to 3, a plurality of holes (suction holes) 21 extending in parallel to the axial direction are formed at equal intervals in the circumferential direction inside the roll of the upper roll 1. Upper roll 1
A sealed space 24 formed by being covered with a seal plate 23 is in contact with one side surface of the suction hole 21, and one end of each suction hole 21 communicates with the sealed space 24. In addition, closed space 2
A suction space 26 communicating with a vacuum suction device (not shown) via a joint 28 is provided inside the roll support shaft 25 on the side where the roll support shaft 4 is formed. Connection hole 27 drilled in
Through the closed space 24.

A plurality of annular grooves (suction grooves) 20 are provided at equal intervals along the axial direction of the upper roll 1 on the surface of the roll cylindrical portion of the upper roll 1. Each suction hole 21 and each suction groove 20 communicate with each other by a connection hole 22.
As a result, the joint 28 connected to the vacuum suction device
When the air is sucked from, the suction force by the negative pressure acts on the core 4 held in the corrugated step portion of the upper roll 1 through the suction groove 20, and the core 4 is brought into close contact with the peripheral surface of the upper roll 1. . In the present single facer, the groove width W of the suction groove 20 is set particularly in the range of 0.5 mm or more and 1.4 mm or less.

As described above, the groove width W of the suction groove 20 is set to approximately 1.4.
mm or less, the step height is 0.4 to 1.2.
It is possible to reduce the occurrence of dry streaks for corrugated cardboard of mm. Here, the lower limit of the groove width W is 0.
The reason for this is that when the groove width W is further reduced, the machining of the suction groove 20 becomes difficult, and it becomes difficult to secure the total amount of suction air. A more preferable range of the groove width W is 0.5 mm or more and 1.1 or more.
mm or less, and setting as described above makes it possible to further reduce the occurrence of dry streaks.

Although not shown, the upper roll 1
The side on which the suction hole 21 is opened is provided with a suction hole 21.
An opening / closing mechanism for opening / closing the opening 21a is provided.
This opening / closing mechanism opens the opening 21a of the suction hole 21 in a predetermined range where the core 4 is held by the upper roll 1, and applies a suction force to the core 4;
1a is closed to prevent useless suction of air. In addition,
The end position (suction end position) of the suction range where the suction force is applied from the upper roll 1 to the core 4 is set near the position where the liner 5 comes into contact with the core 4. On the other hand, the start position (suction start position) of the suction range is preferably shifted by a predetermined angle θ from the meshing position between the upper roll 1 and the lower roll 2 toward the downstream side in the rotation direction of the upper roll 1. In the single facer according to the embodiment, the predetermined angle θ is set particularly in a range of 5 degrees or more and 23 degrees or less.

As described above, the suction start position is shifted by a predetermined angle θ to the downstream side in the rotation direction of the upper roll 1 within a range of approximately 5 degrees to 23 degrees from the meshing position of the upper roll 1 and the lower roll 2. It becomes possible to more effectively reduce the occurrence of dry streaks for a cardboard having a step height of 0.4 to 1.2 mm. Note that the suction start angle θ
If the angle is less than 5 degrees, the effect is small, and if the angle exceeds 23 degrees, the suction timing is too late, and the fluff-out phenomenon in which the core 4 jumps out of the upper roll 1 due to centrifugal force easily occurs.
Stable step molding becomes difficult. Also, the suction start angle θ
Needless to say, there is no shift to the downstream side beyond the gluing position by the glue roll 7.

The operation and effect of the present single facer will be described below based on the test results. In the following, for the sake of convenience, the corrugated cardboard targeted by the present invention is referred to as "micro flute".
Called. <Test Example 1> Here, the width of the suction groove of the upper roll is set to 1.05 ± 0.05 mm, and the suction start position is set at a position downstream of the meshing position of the upper roll and the lower roll in the rotation direction of the upper roll. Using a single facer shifted 10 to 23 degrees, the step height is 0.5 mm and the number of steps is 3
155 double-sided micro flutes were formed per 0 cm. Note that the base paper constituting the micro flute surface coated board 150 g / m ^2, the corrugated medium 115 g / m ^2, a back liner 120 g / m ^2. The suction force acting on the core from the suction groove is about -800 to -1000 mmAq (about -7.8) as measured on the suction pipe side of the suction blower.
~ -9.8 kPa).

When the dry streak state of the micro-float formed by the above setting was confirmed by using an iodine reaction, about 5% of the line (glue line) indicating that glue was attached was found.
0% were connected left and right across the contact portion with the suction groove (the state shown in FIG. 4). Therefore, according to the single facer set as described above, it is possible to manufacture a micro flute in which the occurrence of dry streak which affects operations such as box making is extremely small.

<Test Example 2> Here, the groove width of the suction groove of the upper roll was set to 1.6 ± 0.05 mm, and
Using a single facer in which the suction start position is shifted from the meshing position of the upper roll and the lower roll to the downstream side in the rotation direction of the upper roll by 10 to 23 degrees, the step height is 1.2 mm, and the number of steps is 120 peaks per 30 cm. A double-sided micro flute was formed. Note that the base paper constituting the micro flute surface coated board 150 g / m ^2, the corrugated medium 115 g / m ^2, a back liner 120 g / m ^2. The suction force acting on the core from the suction groove was set to about -800 to -1000 mmAq as measured on the suction pipe side of the suction blower.

When the dry streak state of the microfloat formed by the above setting was confirmed using an iodine reaction, about 30% of the line indicating that the glue had adhered was straddled right and left across the contact portion with the suction groove. It was connected. Therefore, according to the single facer set as described above, it is possible to manufacture a micro flute in which the occurrence of dry streaks that affects operations such as box making is relatively small.

<Test Example 3> Next, the width of the suction groove of the upper roll was set to 1.6 ± 0.05 mm, and the suction start position was set immediately after the mesh position between the upper roll and the lower roll (that is, 5 degrees). Test Example 2 using a single facer
A double-sided micro flute having the same base paper composition, step height, and number of steps was formed. The suction force acting on the core from the suction groove is approximately -800 to -1000 mm as measured on the suction pipe side of the suction blower as in Test Examples 1 and 2.
Aq was set.

When the dry streak state of the microfloat formed by the above setting was confirmed by using an iodine reaction, all the lines indicating that the glue had adhered were interrupted at the contact with the suction groove and were connected to the left and right. (The state shown in FIG. 5). Therefore, when performing operations such as box making using the present micro flute for a paper container, when dry streaks are present at portions other than the ruled line portions, the dry streaks may be easily broken and a problem may occur.

<Test Example 4> Next, the width of the suction groove of the upper roll is set to 1.6 mm, and the suction start position is set at 38 from the meshing position of the upper roll and the lower roll to the downstream side in the rotation direction of the upper roll. Using a single facer shifted
A double-sided micro flute having the same base paper configuration, step height, and step number as in Test Example 2 was formed. The suction force acting on the core from the suction groove was about -800 to -10 as measured on the suction pipe side of the suction blower as in Test Examples 1 to 3.
It was set to 00 mmAq. In the microfloat formed by the above setting, the suction start timing was too late, and a fluff-out phenomenon occurred, and the corrugated core jumped out of the upper roll due to centrifugal force, so that it was difficult to form a stable step.

From the above test results, the following effects were confirmed. First, from Test Example 1 and Test Example 2, the step height was 1.2 mm.
For the following micro flutes, the groove width of the suction groove is 1.4 mm or less, which is 1.4 mm or less, which is less than 1.6 ± 0.05 mm width, and the dry streak can be reduced. Was confirmed. That is, according to the present single facer, by setting the suction groove width to 1.4 mm or less, the phenomenon that the core is drawn into the suction groove is reduced, and the glue adheres from the step top to the thickness direction of the core. This reduces the suction of the part to be dried, thereby reducing the occurrence of dry streak.

From Test Examples 2 and 3, dry streak is reduced by shifting the suction start position from the position where the upper roll and lower roll engage with each other by 10 to 23 degrees downstream in the rotational direction of the upper roll. It was confirmed that it could be done. That is, according to the present single facer, by delaying the suction start timing, the deformation of the core in the suction groove immediately after the step molding can be reduced, and the adhesion of the glue to the step top can be substantially averaged. The occurrence of streaks can be further reduced. Further, from Test Example 4, it was confirmed that if the suction start timing was too late, it was difficult to form a stable step due to the fluff-out phenomenon.

The embodiment of the single facer according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the gist of the present invention. . For example, as a countermeasure to further reduce the occurrence of dry streaks, a configuration in which pressurized air is blown from the suction groove toward the core only at the time when the core is in contact with the pressure belt, and bonding is performed well You can also.

Further, in this embodiment, the liner is bonded to the core by pressing the liner against the core on the upper roll by a pressure belt. However, a press roll is disposed opposite to the upper roll. Alternatively, the liner may be bonded to the core by pressing the liner against the core on the upper roll with a press roll. Further, the positional relationship between the upper roll and the lower roll is not limited to the vertical direction as in the present embodiment, and can be set to an arbitrary positional relationship.

[0036]

As described above in detail, according to the single facer of the present invention, the groove width of the suction groove provided on the surface of the step roll is set within the range of 0.5 mm or more and 1.4 mm or less. Thereby, the occurrence of dry streaks in a cardboard having a step height of 1.2 mm or less can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a single facer as one embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, showing a configuration of an upper roll according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along the line BB of FIG. 2, showing the configuration of an upper roll according to an embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a state of gluing the core with a single facer according to the present invention, showing a state in which the occurrence of dry streak is improved.

FIG. 5 is a conceptual diagram showing a state of gluing of a core by a conventional single facer, showing a state where dry streak has occurred.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper roll (step roll) 2 Lower roll 4 Core 5 Liner 7 Adhesive roll 8 Adhesive 9 Pressure belt 10a, 10b Belt roll 20 Suction groove 21 Suction hole 22 Connection hole 23 Seal plate 24 Sealed space 25 Roll support shaft 26 Suction Space 27 Connecting hole 28 Joint W Suction groove width θ Slip angle of suction start position

Continuing from the front page (72) Inventor Takeo Oishi 4-7-5 Ginza, Chuo-ku, Tokyo Inside Oji Paper Co., Ltd. (72) Inventor Hiroaki Mitamo 4-7-5 Ginza, Chuo-ku, Tokyo Oji Paper Inside (72) Inventor, Nobuhiro Taguchi 4-7-5 Ginza, Chuo-ku, Tokyo Inside Oji Paper Co., Ltd. (72) Inventor Sadao Kango 5-12-8, Ginza, Chuo-ku, Tokyo Oji Packaging Co. F term in the company (reference) 3E078 AA15 BB02 CC12 CC33X

Claims (2)

[Claims] 1. A corrugator single facer comprising: a corrugated roll having a plurality of corrugated steps provided on a surface thereof; and forming corrugated board having a corrugated height of 1.2 mm or less using the corrugated roll. A plurality of suction grooves extending in the circumferential direction of the step roll are provided along the axial direction of the step roll, and the groove width of the suction groove is set within a range of 0.5 mm or more and 1.4 mm or less. Yes, single facer. 2. The suction groove having a groove width of 0.5 mm or more.
The single facer according to claim 1, wherein the single facer is set within a range of 1 mm or less.