JP7128722B2 - Corrugated cardboard box with perforations for dividing body and method for forming perforations for dividing corrugated board - Google Patents

Description

The present invention relates to a corrugated cardboard box with perforations for dividing the body and a method for forming perforations for dividing the corrugated board.

Generally, a corrugated cardboard box has a bottom plate and a cylindrical body extending upward from the bottom plate. Here, perforations extending in the circumferential direction of the body are formed in the body of the cardboard box, and the cardboard is broken along the perforations so that the body can be divided into upper and lower parts and opened. A corrugated cardboard box is known (Patent Documents 1 and 2).

JP 2012-254821 A JP 2008-247476 A

The corrugated cardboard box of Patent Document 1 has perforations only in the back liner out of the front liner, the inner liner, and the back liner that constitute the corrugated cardboard. Sheet-fed corrugated board having such perforations is generally produced by first forming the perforations in the back liner and then laminating the back liner to the corrugated medium with a single facer to form a single face corrugated board. Then, a double facer is used to bond the front liner to the single-faced cardboard to form a continuous double-faced cardboard in the direction of travel, and then a cut-off is used to cut the double-faced cardboard along the direction perpendicular to the direction of travel. formed by

However, the corrugated cardboard box in which only the back liner is perforated, as in Patent Document 1, has the following problems. That is, since the perforation of the back liner is made at the most upstream part of the corrugating machine (upstream side of the single facer), errors in the position of the perforation in the corrugated box are likely to occur due to meandering of the corrugated board running through the corrugating machine. There is a problem. In addition, since perforations are formed only on the back liner and not on the front liner and the inner liner, when the corrugated cardboard is torn along the perforations, the breaking position tends to deviate from the perforations, causing the box to break. There is also the problem that the openability of the package is low.

Therefore, in order to solve this problem, a corrugated cardboard box is proposed in Patent Document 2. In the cardboard box of Patent Document 2, the perforations for dividing the body are divided into a half-cut portion that cuts from the back liner side to the middle of the thickness of the cardboard, and a full-cut portion that penetrates from the back liner side through the middle liner to the front liner side. are arranged alternately. These perforations are formed by inserting a sheet of corrugated cardboard with a cutting die having a blade planted on a flat plate, as shown in FIG. In the corrugated cardboard box of Patent Document 2, the perforations are formed after the corrugated cardboard is cut into sheets, so errors in the positions of the perforations are less likely to occur.

However, forming perforations by sandwiching a piece of corrugated cardboard with a cutting die as in Patent Document 2 has the following problems. That is, when forming perforations by sandwiching a sheet of corrugated cardboard with a punch, after cutting the sheet of corrugated cardboard with a knife of the punch, the cardboard is separated from the punch. As shown in FIG. 4, it is necessary to provide a cork adjacent to the cutting tool, and the pressure of the cork crushes the corrugated cardboard insert in the area of the perforation, which reduces the compressive strength of the box.

The problem to be solved by the present invention is to provide a perforated corrugated cardboard box for splitting the trunk portion which is excellent in opening properties and has high compressive strength.

The inventors of the present application have studied how to improve the openability of the box by making the perforations for dividing the body of the cardboard box into a large number of cuts penetrating between the back liner side and the front liner side. . When forming such perforations, there is a gap between a double facer that forms a corrugated board that is continuous in the direction of travel and a cutoff that cuts the corrugated cardboard along a direction perpendicular to the direction of travel to form sheets. It was found that by using a disk-shaped perforation knife placed in the box, it is possible to form the perforations for dividing the body without lowering the compressive strength of the box.

Based on such findings, the present application provides a perforated corrugated cardboard box for splitting the trunk portion having the following configuration as means for solving the above problems.
Specifically, the bottom plate and
a cylindrical body extending upward from the bottom plate,
The body is a corrugated cardboard having a front liner that forms the outer peripheral surface of the body, a back liner that forms the inner peripheral surface of the body, and a corrugated medium sandwiched between the front liner and the back liner. is formed by
In the corrugated cardboard box in which perforations for dividing the body into upper and lower parts are formed in the body,
The perforation has a configuration in which a large number of cuts penetrating between the back liner side and the front liner side are arranged in a straight line in the circumferential direction of the body,
The perforations are formed without crushing the medium so that the difference between the thickness of the cardboard in the area along the perforations and the maximum thickness of the cardboard in other areas is less than 1 mm.
To provide a corrugated cardboard box with perforations for splitting a trunk, characterized by:

With this configuration, since the perforations are made up of a large number of cuts penetrating between the back liner side and the front liner side, when the corrugated cardboard is torn along the perforations, the breaking position deviates from the perforations. Easy to open the box. In addition, since the difference between the thickness of the corrugated cardboard in the area along the perforations for dividing the trunk and the maximum thickness of the corrugated board in the other area is less than 1 mm, the corrugated medium is formed without crushing. The compressive strength of the box is high.

The perforations are such that the length dimension of each cut on the front liner side along the direction in which the perforation extends is smaller than the length dimension on the back liner side of each cut along the direction in which the perforation extends. It is preferable to form

With this configuration, the length of each cut forming the perforation is shorter on the side of the front liner that forms the outer peripheral surface of the barrel than on the side of the back liner that forms the inner peripheral surface of the barrel. It is possible to prevent the connecting portion between the adjacent cuts from breaking due to an impact from an impact or the like.

Further, the perforation is such that the width dimension of the front liner side of each cut along the direction perpendicular to the extending direction of the perforation is equal to the width dimension of the back liner side of each cut along the direction perpendicular to the extending direction of the perforation. It is preferable to form it so that it is smaller than the width dimension of .

With this configuration, the width of each cut forming the perforations is smaller on the side of the front liner that forms the outer peripheral surface of the barrel than on the side of the back liner that forms the inner peripheral surface of the barrel. It is possible to prevent the connecting portion between the adjacent cuts from breaking due to an impact from an impact or the like.

In addition, the present invention provides a perforation forming method having the following configuration as a method for forming perforations for dividing corrugated cardboard suitable for manufacturing the perforated corrugated cardboard box for dividing the trunk portion.
Specifically, a double facer that forms a continuous corrugated board in the traveling direction by laminating a front liner to a single-faced corrugated board consisting of a corrugated inner liner and a back liner,
a cut-off disposed downstream of the double facer and cutting the corrugated cardboard along a direction orthogonal to the direction of travel into sheets;
A perforation having a disk-shaped perforation knife arranged downstream of the double facer and upstream of the cutoff, and having a plurality of radially outwardly protruding blades provided on the outer circumference at regular intervals. using a forming device and
The perforation knife is configured such that a large number of cuts penetrating between the back liner side and the front liner side are arranged in a straight line in the advancing direction, and the perforation for dividing the corrugated cardboard in the area along the perforation. and the maximum thickness of the cardboard in other areas is less than 1 mm.
A method for forming perforations for dividing corrugated board is provided.

In this manner, perforations are formed by the disc-shaped perforation knife on the corrugated board that is continuous in the direction of travel (that is, the corrugated board before being cut off into sheets), so that the corrugated medium is crushed. It is possible to form corrugated cardboard dividing perforations consisting of a large number of cuts penetrating between the back liner side and the front liner side without cutting.

It is preferable to use a perforation knife arranged to cut into the corrugated cardboard from the back liner side.

With this configuration, the perforation has a length dimension on the front liner side of each cut along the direction in which the perforation extends, which is smaller than a length dimension on the back liner side of each cut along the direction in which the perforation extends, Perforations in which the width dimension of the front liner side of each cut along the direction perpendicular to the extending direction of the perforation is smaller than the width dimension of the back liner side of each cut along the direction perpendicular to the extending direction of the perforation. can be formed.

It is preferable to form a radially outer edge cutting edge, a rotationally forward edge cutting edge, and a rotationally rearward edge cutting edge on each of the edge portions on the outer periphery of the perforation knife.

In this way, the cutting edge formed on the front edge of each blade in the rotation direction can effectively reduce the resistance when each blade of the perforated knife cuts into the cardboard, so that the perforated knife can be used. It is possible to effectively prevent the inside of the cardboard from being crushed by the resistance when each blade cuts into the cardboard.

The corrugated cardboard box with perforations for splitting the body of the present invention employs perforations consisting of a large number of cuts penetrating between the back liner side and the front liner side, so that when the corrugated cardboard is torn along the perforations, In addition, the breaking position is less likely to shift from the perforations, making it easier to open the box. In addition, since the difference between the thickness of the corrugated cardboard in the area along the perforations for dividing the trunk and the maximum thickness of the corrugated board in the other area is less than 1 mm, the corrugated medium is formed without crushing. The compressive strength of the box is high.

FIG. 2 is a view of the cardboard box blank according to the first embodiment of the present invention, viewed from the front liner side; (A) is an enlarged view of the vicinity of the perforations of the blank shown in FIG. 1 as seen from the back liner side, and is a view corresponding to the left side view of (B), and (B) is taken along line IIB-IIB of FIG. (C) is an enlarged view of the vicinity of the perforations of the blank shown in FIG. 1 as seen from the front liner side, corresponding to the right side view of (B) FIG. 2 is an enlarged cross-sectional view along the perforations of the blank shown in FIG. 1; FIG. 2 is a perspective view showing a cardboard box obtained by assembling the blanks shown in FIG. 1; FIG. 5 is a perspective view showing a state in which the trunk portion of the cardboard box shown in FIG. 4 is broken along perforations and divided into upper and lower parts; FIG. 5 is a diagram schematically showing the part after the double facer of the corrugating machine for manufacturing the corrugated cardboard box shown in FIG. Enlarged cross-sectional view showing the vicinity of the perforation forming device of FIG. FIG. 8 is an enlarged sectional view near the perforation knife of the perforation forming device shown in FIG. 7 ; Enlarged view of the blade portion of the perforated knife shown in FIG. Cross-sectional view along line XX in Fig. 9 (a) is a photograph of a cross section of a sample of corrugated cardboard with perforations formed with the perforation knife shown in FIG. A photograph of a cross-section of a sample of corrugated cardboard with perforations formed with the perforation knife of No. 9, cut at the position of the cut that constitutes the perforation. (a) is a photograph of a cross section of a sample of corrugated cardboard in which perforations are formed by sandwiching a sheet of corrugated cardboard with a cutting die, cut at the position of the joint between adjacent cuts of the perforations; ) is a photograph of a cross-section of a sample of corrugated cardboard with perforations formed by sandwiching a piece of corrugated cardboard with a cutting die, cut at the position of the perforation. A photograph taken from the back liner side of the perforations formed on the cardboard with the perforation knife shown in FIGS. 9 and 10 Photograph taken from the back liner side of perforations formed on corrugated cardboard with a perforation knife that does not have cutting edges on the front and rear edges of the blades on the outer circumference of the perforation knife in the rotational direction. Photograph of perforations formed by sandwiching cardboard with a cutting die with a cutting tool planted on a flat plate, taken from the back liner side FIG. 11 is a view of a cardboard box blank according to a second embodiment of the present invention, viewed from the front liner side; A perspective view showing an example of an unsealed state of a cardboard box obtained by assembling the blanks shown in FIG. FIG. 11 is a view of a cardboard box blank according to a third embodiment of the present invention, viewed from the front liner side; A perspective view showing an example of an unsealed state of a cardboard box obtained by assembling the blanks shown in FIG. FIG. 4 is a view of a cardboard box blank according to a fourth embodiment of the present invention, viewed from the front liner side; FIG. 20 is a perspective view showing an example of an opened state of a corrugated cardboard box obtained by assembling the blanks shown in FIG. FIG. 5 is a view of a cardboard box blank according to a fifth embodiment of the present invention, viewed from the front liner side; A perspective view showing an example of an unsealed state of a cardboard box obtained by assembling the blanks shown in FIG. FIG. 6 is a view of a cardboard box blank according to a sixth embodiment of the present invention, viewed from the front liner side; FIG. 24 is a perspective view showing a cardboard box obtained by assembling the blanks shown in FIG. The perspective view which shows an example of the unsealing state of the cardboard box shown in FIG. FIG. 11 is a view of a cardboard box blank according to a seventh embodiment of the present invention, viewed from the front liner side; FIG. 27 is a perspective view showing an example of an opened state of a corrugated cardboard box obtained by assembling the blanks shown in FIG.

FIG. 1 shows a blank of a corrugated cardboard box with perforations for splitting a body portion according to a first embodiment of the present invention. The blank is formed of corrugated board having a front liner 1 , a back liner 2 and a corrugated midsole 3 sandwiched between the front liner 1 and the back liner 2 . This blank has rectangular side plates 5 , 6 , 7 , 8 which are successively connected via a ruled line 4 . The ruled lines 4 extend in a direction parallel to corrugations of the cardboard. The side edge of the side plate 8 located at the end is connected with a joint allowance 10 through a ruled line 9. - 特許庁As shown in FIG. 4, the side plates 5, 6, 7, and 8 constitute the body portion 31 when the corrugated cardboard box 30 is assembled. The back liner 2 constitutes the inner peripheral surface of the body portion 31 of the corrugated cardboard box 30 .

As shown in FIG. 1, upper flaps 12, 13, 14, and 15 are connected to the upper edges of the side plates 5, 6, 7, and 8 via ruled lines 11, respectively. The ruled lines 11 extend in a direction perpendicular to corrugations of the cardboard. Between the adjacent upper flaps 12, 13, 14, 15, cut grooves 16 parallel to the steps are provided. It's becoming

Lower flaps 18, 19, 20, and 21 are connected to the lower edges of the side plates 5, 6, 7, and 8 via ruled lines 17, respectively. The ruled lines 17 extend in a direction perpendicular to corrugations of the cardboard. Between the adjacent lower flaps 18, 19, 20, 21, cut grooves 22 parallel to the step are provided. It's becoming

The blank is formed with perforations 23 extending longitudinally across the blank in a direction perpendicular to the corrugation of the cardboard. The perforations 23 pass through the side plates 5, 6, 7, 8 and the joint 10 so as to divide the side plates 5, 6, 7, 8 and the joint 10 into upper and lower parts. As shown in FIG. 5, the perforation 23 is a body dividing perforation for dividing the body 31 into upper and lower parts by breaking the cardboard along the perforation 23 when the cardboard box 30 is assembled. is.

As shown in FIG. 1, the side plate 5 has a fold line 24 extending parallel to the perforation 23 at a position spaced from the perforation 23 , and a fold line 24 extending between both ends of the fold line 24 and the perforation 23 . A pair of break lines 25 extending to connect are formed. The other side plates 6, 7 and 8 are also formed with similar crease lines 24 and breaking lines 25. As shown in FIG.

As shown in FIGS. 2(A), (B), and (C), the perforation 23 consists of a large number of cuts 26 penetrating between the back liner 2 side and the front liner 1 side and arranged in a straight line. It is said to be composed. Each cut 26 is formed in a slit shape extending linearly in a direction perpendicular to the corrugation of the corrugated cardboard, and these cuts 26 are arranged so as to line up on a straight line perpendicular to the corrugation of the corrugated board.

As shown in FIG. 3, the perforations 23 are such that the length dimension L1 on the front liner ₁ side of each cut 26 along the direction in which the perforation 23 extends is equal to the length dimension L1 of each cut 26 along the direction in which the perforation 23 extends. is formed to be smaller than the length dimension L2 on the side of the back liner ₂ . The length L3 of the connecting portion between adjacent cuts 26 on the side of the front liner ₁ is 2.5 mm or more and 4.5 mm or less (preferably 3.0 mm or more and 4.0 mm or less). In addition, the length L4 of the connecting portion between adjacent cuts 26 on the back liner 2 side is set to 2 mm or more and ₄ mm or less (preferably 2.5 mm or more and 3.5 mm or less).

The perforation 23 has a thickness T of the cardboard in the area along the perforation 23 (see FIG. 2B) and a maximum thickness of the cardboard in the other area (for example, the ruled line 11 of the side plate 5 shown in FIG. 1). The corrugating medium 3 (see FIG. 3) is formed without being crushed so that the difference between the perforations 23 and the thickness of the cardboard at the intermediate portion) is less than 1 mm.

As shown in FIGS. 2A and 2C, the perforation 23 has a width dimension W1 of each cut 26 on the side of the front liner ₁ along the direction orthogonal to the direction in which the perforation 23 extends. It is formed to be smaller _than the width dimension W2 of each cut 26 on the side of the back liner 2 along the direction orthogonal to the direction in which the liner 23 extends.

The blank shown in FIG. 1 can be assembled, for example, as follows.

The side plates 5, 6, 7, 8 are bent into a cylindrical shape along the ruled line 4 so that the back liner 2 faces inward, and the joint margin 10 connected to the side plate 8 at one end is adhered to the inner surface of the side plate 5 at the other end. These side plates 5, 6, 7 and 8 form a trunk portion 31 (see FIG. 4). Next, the lower flaps 18, 20 connected to the lower ends of the side plates 5, 7 are bent inside the body portion 31 along the ruled lines 17, and then the lower flaps 19 connected to the lower ends of the side plates 6, 8 are bent. , 21 are folded along the ruled line 17 to the inside of the body 31, and the lower flaps 18, 19, 20, 21 form a bottom plate 32 (see FIG. 4) that closes the lower end opening of the body 31, and the product 33 ( 5) are boxed. After that, the upper flaps 12, 14 connected to the upper ends of the side plates 5, 7 are bent inside the body portion 31 along the ruled lines 11, and then the upper flaps 13, 15 connected to the upper ends of the side plates 6, 8 are bent. are bent toward the inside of the body portion 31 along the ruled line 11, and the upper flaps 12, 13, 14, and 15 form a top plate 34 (see FIG. 4) that closes the upper end opening of the body portion 31. As shown in FIG. At this time, the bottom plate 32 is opposed to the bottom of the top plate 34, the top plate 34 and the bottom plate 32 are connected by a cylindrical body portion 31, and the body portion 31 is formed with perforations 23 for dividing the body portion. state. The cuts 26 forming the perforations 23 are arranged in a straight line in the circumferential direction of the body portion 31 .

As shown in FIG. 5, the corrugated cardboard box 30 can be opened by breaking the corrugated cardboard along the perforations 23 and dividing the body portion 31 of the corrugated cardboard box 30 into upper and lower parts. At this time, if the breaking line 25 is broken, a finger is inserted into the portion surrounded by the breaking line 25, the folding line 24, and the perforation 23, and the upper portion of the body portion 31 above the perforation 23 is pulled up, The division of the trunk portion 31 can be performed smoothly.

As described above, the cardboard box 30 employs perforations 23 in which a large number of cuts 26 penetrating between the back liner 2 side and the front liner 1 side are arranged in a straight line in the circumferential direction of the body portion 31. Therefore, when the corrugated cardboard is torn along the perforations 23, the fracture position is less likely to deviate from the perforations 23, and the box can be easily opened. In addition, the corrugating medium 3 is formed without being crushed so that the difference between the thickness T of the corrugated board in the area along the perforations 23 for dividing the trunk and the maximum thickness of the corrugated board in the other area is less than 1 mm. Therefore, the compressive strength of the box is high.

Further, in the corrugated cardboard box 30, the cuts forming the perforations 23 are located on the side of the front liner 1 forming the outer peripheral surface of the body portion 31 rather than on the side of the back liner 2 forming the inner peripheral surface of the body portion 31. Since the length of the cut 26 is short, it is possible to prevent the connecting portion between the adjacent cuts 26 from breaking due to an external impact or the like.

Further, in the corrugated cardboard box 30, the cuts forming the perforations 23 are located on the side of the front liner 1 forming the outer peripheral surface of the body portion 31 rather than on the side of the back liner 2 forming the inner peripheral surface of the body portion 31. Since the width dimension of 26 is small, it is possible to prevent the connecting portion between adjacent cuts 26 from breaking due to external impact or the like.

Next, a method of forming perforations for dividing corrugated cardboard suitable for manufacturing the corrugated cardboard box 30 of the above-described embodiment will be described.

FIG. 6 is a diagram schematically showing the portion after the double facer of the corrugating machine for manufacturing corrugated board. The corrugating machine has a single facer (not shown) that laminates the back liner 2 to the corrugated corrugated medium 3 to form a single-faced corrugated board, and laminates the front liner 1 to the single-faced corrugated board, in order from the upstream side to the downstream side. A double facer 40 that forms a continuous double-faced corrugated board S in the direction of travel, and a slitter that cuts the double-faced corrugated board S continuously in the direction of travel into a plurality of strips along the direction of travel (that is, the direction perpendicular to the corrugations). A slitter scorer 42 having a knife 41, a perforation forming device 44 having a disk-shaped perforation knife 43, a cutoff 45 for cutting the cardboard S along the direction orthogonal to the traveling direction into sheets, and the cutoff 45. A sheet stacker 46 is provided for stacking the cardboard sheets S to form a pile of sheets. The perforation forming device 44 is arranged downstream of the double facer 40 (downstream of the slitter scorer 42 in this embodiment) and upstream of the cutoff 45 . In this corrugating machine, the corrugated board S runs with the front liner 1 on the bottom and the back liner 2 on the top.

As shown in FIG. 7, the slitter scorer 42 is fixed to rotating shafts 47 and 48 arranged above and below the cardboard S, a knife receiver 49 fixed to the upper rotating shaft 47, and a lower rotating shaft 48. upper and lower rotating shafts 50 and 51 arranged parallel to the rotating shafts 47 and 48; a ruled line ring 52 fixed to the upper rotating shaft 50; and a ruled line ring 53 . The slitter knife 41 has a circumferentially continuous cutting edge along the entire circumference. The upper and lower ruled line rings 52 and 53 sandwich the cardboard S to form ruled lines 11 and 17 (see FIG. 1) in a direction perpendicular to the corrugated board.

The slitter scorer 42 includes a frame 54 supporting the upper rotating shafts 47 and 50 and the lower rotating shafts 48 and 51, a base member 55 fixed to the floor surface F, and between the frame 54 and the base member 55. and a linear guide 56 provided. The linear guide 56 supports the frame 54 so as to be movable in a horizontal direction orthogonal to the direction in which the cardboard S advances. Further, when the position of the cardboard S passing through the slitter scorer 42 changes in the direction orthogonal to the traveling direction, a frame moving device 57 is attached to the frame 54 to move the frame 54 following the change in the position of the cardboard S. It is

The perforation forming device 44 includes rotating shafts 60 and 61 arranged above and below the cardboard S, a disk-shaped perforating knife 43 fixed to the upper rotating shaft 60, and a lower rotating shaft 61. and a knife receiver 62 . The perforation knife 43 is a rotary blade that cuts into the cardboard S from the upper side (that is, the back liner 2 side) to the lower side (that is, the front liner 1 side) to form perforations 23 (see FIG. 1) in the cardboard S. is.

The perforation forming device 44 has a frame 63 supporting the rotating shafts 60 and 61 , a base member 64 fixed to the floor surface F, and a linear guide 65 provided between the frame 63 and the base member 64 . The linear guide 65 supports the frame 63 so as to be movable in the horizontal direction orthogonal to the traveling direction of the cardboard S. The frame 63 is provided with a connection bracket 66 that is connected to the frame 54 of the slitter scorer 42 . By connecting the frame 63 and the frame 54 to each other via the connecting bracket 66, when the frame moving device 57 moves the frame 54 of the slitter scorer 42, the frame of the perforation forming device 44 is integrated with the frame 54. 63 is also designed to move.

The perforation forming device 44 also has an elevation drive device 67 for the perforation knife 43 . When the perforations 23 are not formed on the cardboard S, the elevation drive device 67 raises the perforation knife 43, and when the perforations 23 are formed on the cardboard S, the elevation drive device 67 lowers the perforation knife 43.

As shown in FIG. 8, the perforation knife 43 has a plurality of radially outwardly protruding blades 68 provided at equal intervals in the circumferential direction on the outer periphery thereof. The radially outer edge of each blade 68 is arc-shaped with its center at the same position as the center of the rotating shaft 60 .

As shown in FIGS. 9 and 10, the blade portion 68 has a cutting edge 69 on the radially outer edge, a cutting edge 70 on the front edge in the rotational direction, and a cutting edge 71 on the rear edge in the rotational direction. . Each of the cutting edges 69, 70, 71 is a ridgeline where both side surfaces of the blade portion 68 intersect at an acute angle.

When the corrugated board S is manufactured by this corrugating machine, if the perforations 23 for dividing the body part are formed by the perforation knife 43, the corrugated board S that is continuous in the traveling direction (that is, before being cut off 45 into sheets) is formed. Since the perforations 23 are formed in the corrugated cardboard (S) with a disk-shaped perforation knife 43, a large number of cuts 26 penetrating between the back liner 2 side and the front liner 1 side without crushing the core 3 of the corrugated cardboard S). It is possible to form the body part dividing perforation 23 consisting of. Specifically, the trunk part dividing perforation 23, which has a configuration in which a large number of cuts 26 penetrating between the back liner 2 side and the front liner 1 side are arranged in a straight line in the traveling direction, is formed along the perforation 23. The corrugating medium 3 can be formed without crushing so that the difference between the thickness T of the corrugated board S in the area and the maximum thickness of the corrugated board S in the other area is less than 1 mm.

In addition, since the perforation knife 43 cuts into the cardboard S from the back liner 2 side toward the front liner 1 side, as shown in FIG. The length L1 of the cuts 26 on the front liner ₁ side is smaller than the length L2 of each cut 26 on the back liner ₂ side along the direction in which the perforations 23 extend. Further, as shown in FIGS. 2A and 2C, the perforations 23 have a width dimension W1 of each cut 26 on the front liner ₁ side along the direction perpendicular to the direction in which the perforations 23 extend. It is smaller than the width dimension W2 of each cut 26 on the side of the back liner ₂ along the direction perpendicular to the direction in which the perforation 23 extends.

As shown in FIGS. 9 and 10, since a cutting edge 70 is formed on the front edge of each blade 68 in the rotational direction, the resistance when each blade 68 of the perforated knife 43 cuts into the cardboard S is reduced. can be effectively reduced. Therefore, it is possible to effectively prevent the core 3 of the cardboard S from being crushed by the resistance when the blades 68 of the perforated knife 43 cut into the cardboard S. That is, it is possible to adopt a configuration in which the cutting edge 69 is provided only on the radially outer edge of the blade portion 68, and the cutting edges 70 and 71 are not provided on the front and rear edges in the rotational direction. As a result, when the cutting edge 68 cuts into the cardboard S, the resistance increases, so that when the perforations 23 are formed in the cardboard S, the corrugating medium 3 may be crushed such that the thickness of the cardboard S is reduced by 1 mm or more. On the other hand, as shown in FIGS. 9 and 10, if the blade portion 68 has a cutting edge 70 on the front side in the rotation direction and a cutting edge 71 on the rear side in the rotation direction, It is possible to effectively reduce the resistance when the blade part 68 cuts into the cardboard S, and as a result, when the perforations 23 are formed in the cardboard S, the thickness of the cardboard S is 1 mm or more in the area along the perforations 23. It is possible to prevent the collapse of the midsole 3 which decreases.

As shown in FIGS. 9 and 10 , cutting edges 70 and 71 are formed on the front edge in the rotational direction and the rear edge in the rotational direction of the blade portion 68 , so that the perforated knife 43 can When the perforations 23 are formed, both ends of each of the cuts 26 forming the perforations 23 are straightly cut in the direction in which the perforations 23 extend, thereby forming the body of the box along the perforations 23. When breaking the body 31, the breaking of the body 31 becomes extremely smooth.

That is, if the cutting edge 68 is not provided with the cutting edges 70 and 71 on the front and rear edges in the rotational direction, and only the cutting edge 69 on the radially outer edge is provided (that is, the cutting edge 68 along the rotational direction) When the perforations 23 are formed using a blade portion 68 formed so that the thickness does not change and is constant, as shown in FIG. It becomes a shape that spreads in a direction perpendicular to the direction in which the eye 23 extends (a serif "I" shape).

On the other hand, as shown in FIGS. 9 and 10, cutting edges 70 and 71 are provided on the edge of the blade portion 68 on the front side in the rotation direction and on the edge on the rear side in the rotation direction, respectively. Using a perforated knife 43 in which each blade portion 68 is formed so that the thickness in the orthogonal direction gradually decreases toward the cutting edge 70 on the front side in the rotation direction and the cutting edge 71 on the rear side in the rotation direction. When the perforation 23 is formed, as shown in FIG. 13, both ends of each cut 26 forming the perforation 23 are cut straight in the direction in which the perforation 23 extends. Therefore, when breaking the body portion 31 of the box along the perforations 23, the breaking of the body portion 31 becomes extremely smooth.

FIG. 15 shows perforations 23 formed by sandwiching the cardboard S with a cutting die having a cutting tool planted on a flat plate in a box-making process for processing sheet-fed cardboard. 14, the perforation 23 also has a shape in which both ends of each of the cuts 26 forming the perforation 23 spread in a direction orthogonal to the extending direction of the perforation 23 (serif letter "I"). shape).

In order to confirm that the perforation 23 is prevented from being crushed in the area along the perforation 23 when the perforation 23 is formed by the perforation knife 43 of the above embodiment, A sample of corrugated cardboard with perforations 23 formed thereon and a sample of corrugated cardboard with perforations 23 formed by sandwiching sheet-fed corrugated cardboard with a punching die as in Japanese Patent Application Laid-Open No. 2008-247476 (Patent Document 2) are produced. did. Then, a cross section (see FIGS. 11(a) and 12(a)) when each sample is cut at the position of the connecting portion between the adjacent cuts 26 of the perforation 23, and the cut 26 of the perforation 23 11 (b) and 12 (b)) were observed. As a result, as shown in FIGS. 11(a) and 11(b), in the sample in which the perforation 23 was formed by the perforation knife 43 of the above embodiment, the thickness of the corrugated cardboard was reduced by 1 mm or more in the area along the perforation 23. 12(a) and 12(b), perforations 23 are formed by sandwiching the sheet-fed corrugated cardboard with a cutting die. It can be seen that the thickness of the corrugated cardboard of the sample is reduced by 1 mm or more (approximately 1.8 mm in the figure) in the area along the perforations 23 due to the crushing of the corrugating medium 3 .

In the above-described embodiment, the side plates 5, 6, 7, and 8, which are connected in order via the ruled line 4, are bent into a cylindrical shape to form the trunk portion 31, and the upper edge of each of the side plates 5, 6, 7, and 8 is ruled. The top plate 34 is formed by the upper flaps 12, 13, 14, 15 connected via the flaps 11, and the lower flaps connected to the lower edges of the side plates 5, 6, 7, 8 via the ruled lines 17. Although the cardboard box 30 (so-called A-type cardboard box) in which the bottom plate 32 is formed by the flaps 18, 19, 20, and 21 has been described as an example, the present invention includes a bottom plate and a cylindrical body extending upward from the bottom plate. It can also be applied to other types of corrugated cardboard boxes as long as they have sections, e.g., without the top plate 34 formed by the top flaps 12, 13, 14, 15, the bottom flaps 18, 18, 18, 18, 18, 18 It can also be applied to a so-called semi-A type corrugated cardboard box consisting only of a bottom plate 32 formed by 19, 20 and 21 and a cylindrical body portion 31 extending upward from the bottom plate 32. In addition, as shown in FIG. 7 of Japanese Patent Application Laid-Open No. 2008-247476 (Patent Document 2), the top plate, the first side plate among the four side plates of the cylindrical body, the bottom plate, and the first side plate It is also possible to apply to a wrap-around case in which the opposing second side plates are successively arranged via ruled lines. When applied to a wrap-around case, the perforations for dividing the body are formed by the first side plate, the inner flaps connected to both sides of the first side plate via ruled lines, the second side plate, and the second side plate. It can be formed with an inner flap continuously provided on both sides of the side plate via a ruled line. Furthermore, among the four side plates of the cylindrical body, the first side plate, the bottom plate, and the second side plate facing the first side plate are successively connected via a ruled line, and are separate top plates. It can also be applied to closed multi-piece packaging boxes (so-called tray lidders, etc.).

16 and 17 show the blank of the perforated corrugated cardboard box for splitting the trunk portion of the second embodiment, and the unsealed state of the corrugated cardboard box 30 obtained by assembling the blank. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

The side plates 5, 6, 7, 8 are composed of side plates 5, 7 forming width surfaces (short width surfaces) and side plates 6, 7 forming length surfaces (long width surfaces) when the cardboard box 30 is assembled. 8.

As shown in FIG. 16, the side plates 5 and 7 forming the width surfaces are provided with a first fracture line 72 extending in an arc shape and having both ends connected to the perforation 23 so that the perforation 23 is a chord. A second break line 73 extending from the center of the break line 72 toward the upper flaps 12 and 14 and reaching the ruled line 11 is formed. The side plates 6 and 8 forming the longitudinal planes are also formed with a third breaking line 74 extending in an arc shape with both ends connected to the perforation 23 so that the perforation 23 is a chord.

A corrugated cardboard box 30 obtained by assembling the blanks shown in FIG. By breaking the side plates 5 and 7 that constitute the The upper part of the body part 31 divided along the break line 73 of the cardboard box 30 can be swung upward along the central position of the top plate 34 (the position where the upper flaps 13 and 15 meet), and the inside of the cardboard box 30 It can be left open on one side so that the product can be partially removed and resealed. Here, since the first breaking line 72 is arc-shaped, when the upper portions of the side plates 5 and 7 divided along the perforations 23 are swung upward, the division along the perforations 23 is performed. It is possible to prevent the lower edges of the upper parts of the side plates 5 and 7 which are separated from interfering with the upper edges of the lower parts of the side plates 5 and 7 which are divided along the perforations 23. - 特許庁

18 and 19 show the blank of the corrugated cardboard box with perforations for splitting the trunk portion of the third embodiment and the unsealed state of the corrugated cardboard box 30 obtained by assembling the blank. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 18 , a break line 75 is formed between the perforation 23 and the ruled line 11 in the ruled line 4 to separate the adjacent side plates 5 , 6 , 7 , 8 . A break line 76 for separating the side plate 8 and the joint allowance 10 is also formed in a portion of the ruled line 9 between the perforation 23 and the ruled line 11 . A break line 25 for inserting a fingertip is formed at the center position of the perforation 23 of each side plate 5, 6, 7, 8. As shown in FIG. In the figure, the break lines 75 and 76 are composed of two cuts penetrating between the front liner 1 and the back liner 2 in order to ensure the compressive strength of the box. It is also possible to configure with perforations consisting of a large number of cuts penetrating the .

The corrugated cardboard box 30 obtained by assembling the blanks shown in FIG. By separating the adjacent side plates 5, 6, 7, 8 along the line 76 and the joint margin 10 along the breaking line 76 and the ruled line 9, the portion of the body 31 on the top plate 34 side is flattened. It can be folded into That is, since the work of opening the corrugated cardboard box 30 and the work of dismantling the portion of the body portion 31 on the side of the top plate 34 can be performed at the same time, the workability of displaying the products 33 is excellent. 5 of the first embodiment, compared to the case where the top plate 34 side portion of the body portion 31 is removed while maintaining the cylindrical shape, the top plate 34 side portion of the body portion 31 is removed from the outside. Since the product can be removed while being opened, the trunk portion 31 can be removed without interfering with the product 33, and the workability of unsealing is excellent.

20 and 21 show a blank of a corrugated cardboard box with perforations for splitting the trunk portion of the fourth embodiment, and an unsealed state of the corrugated cardboard box 30 obtained by assembling the blank. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 20, the side plate 5 has a pair of first breaking lines 77 extending vertically to connect between the perforations 23 and the ruled lines 11 and facing left and right. A pair of second break lines 78 extending from the upper end of 77 to both sides along ruled line 11 to reach the side edges of side plate 5 are formed. The other side plates 6, 7 and 8 are similarly formed with a first break line 77 and a second break line 78. As shown in FIG.

The corrugated cardboard box 30 obtained by assembling the blanks shown in FIG. , 8, the bent portions between the side plates 5, 6, 7, 8 can be left in a vertically extending columnar shape and opened. Therefore, as shown in FIG. 21, the cardboard boxes 30 can be stacked up and down while the cardboard boxes 30 are opened and the products 33 are exposed. Further, as in the third embodiment, when the cardboard box 30 is opened, the opening operation of the cardboard box 30 and the dismantling operation of the portion of the body portion 31 on the side of the top plate 34 can be performed at the same time. Excellent workability for displaying No. 33.

22 and 23 show the blank of the perforated corrugated cardboard box for splitting the body portion of the fifth embodiment, and the unsealed state of the corrugated cardboard box 30 obtained by assembling the blank. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

The side plates 5, 6, 7, 8 are composed of side plates 5, 7 forming width surfaces (short width surfaces) and side plates 6, 7 forming length surfaces (long width surfaces) when the cardboard box 30 is assembled. 8.

As shown in FIG. 22, the side plate 6 forming the length surface is formed with a pair of first breaking lines 79 extending vertically to connect between the perforations 23 and the ruled lines 11 and facing left and right. The upper flap 13 connected to the upper edge of the side plate 6 is formed with a second break line 80 extending in a U shape so as to connect the upper ends of the pair of first break lines 79 . Similarly, a first break line 79 and a second break line 80 are also formed in the other side plate 8 constituting the longitudinal surface and the upper flap 15 connected to the upper edge of the side plate 8. .

Both side edges of the upper flaps 12 and 14 connected to the upper edges of the side plates 5 and 7 that constitute the width surface are the second side edges of the upper flaps 13 and 15 when the cardboard box 30 is assembled as shown in FIG. A region surrounded by a break line 80 is cut out in an L shape so as not to overlap the upper flaps 12 and 14. - 特許庁The side plates 5 and 7 forming the width surfaces are formed with a breaking line 81 extending in a C shape for removing an adhesive tape 82 (see FIG. 23). 23, the tips of the upper flaps 13 and 15 are connected with an adhesive tape 82, and both ends of the adhesive tape 82 are attached to the side plates 5 and 7. As shown in FIG.

The corrugated cardboard box 30 obtained by assembling the blanks shown in FIG. By breaking the folded upper flap 15 along the U-shaped second breaking line 80, the window for taking out the product can be opened. The corrugated cardboard boxes 30 can be stacked up and down while the commodity is exposed by opening the window for taking out the commodity. Similarly, the side plate 6 is broken along the perforations 23 and the first breaking line 79, and the upper flap 13 connected to the upper edge of the side plate 6 is cut along the U-shaped second breaking line 80. It is also possible to open a window for taking out the product by breaking it.

24 to 26 show a blank of a corrugated cardboard box with perforations for dividing the trunk of the sixth embodiment, a corrugated board 30 obtained by assembling the blank, and an unsealed state of the corrugated board 30. FIG. The corrugated cardboard box with perforations for dividing the body portion of the sixth embodiment is a so-called wrap-around case. Parts corresponding to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 24 , the blank has a top plate 34 , a side plate 83 , a bottom plate 32 , and a side plate 84 that are connected in order via ruled lines 85 . The ruled lines 85 are fold lines extending in a direction perpendicular to corrugations of the cardboard. A joint allowance 87 is continuously provided on the side plate 84 via a ruled line 86 . End flaps 89 are connected to both sides of the top plate 34 , the side plates 83 , the bottom plate 32 , and the side plates 84 via ruled lines 88 . The end flap 89 connected to the top plate 34, the end flap 89 connected to the side plate 83, the end flap 89 connected to the bottom plate 32, and the end flap 89 connected to the side plate 84 all have the same length. and the leading edge of each end flap 89 is collinear. The side plates 83, side plates 84, and end flaps 89 constitute the body portion 31 when the cardboard box 30 is assembled, as shown in FIG.

The blank shown in FIG. 24 is formed with two parallel perforations 23 extending longitudinally across the blank in a direction perpendicular to the corrugation of the cardboard. One of the two perforations 23 extends through the side plate 83 and the end flaps 89 so as to vertically divide the side plate 83 and the end flaps 89 connected to the left and right of the side plate 83 . The other perforation 23 extends through the side plate 84 and the end flaps 89 so as to vertically divide the side plate 84 and the end flaps 89 connected to the left and right of the side plate 84 . The perforation 23 of the side plate 83 is arranged at the center position of the side plate 83 in the vertical direction. The perforation 23 of the side plate 84 is also arranged at the center position of the side plate 84 in the vertical direction. As shown in FIG. 25, these two perforations 23 are used to divide the body 31 into upper and lower parts by breaking the cardboard along the perforations 23 when the cardboard box 30 is assembled. It is a dividing perforation. As shown in FIG. 24, at the center of the perforations 23 of the side plates 83 and 84, a breaking line 25 is formed for inserting a fingertip when splitting the body 31 of the box.

The blank shown in FIG. 24 can be assembled, for example, as follows.

The blank is placed so that the back liner 2 faces upward, and the product 33 (see FIG. 26) is placed on the bottom plate 32 . Then, the product 33 is wrapped with side plates 83, 84 bent upward with respect to the bottom plate 32 and a top plate 34 bent horizontally along the upper edge of the side plate 83, and the top plate 34 is attached to a joint margin 87. Glue to form a cylinder. After that, both ends of the cylindrical body are closed with respective end flaps 89 and adhered to obtain the corrugated cardboard box 30 containing the product 33 as shown in FIG. At this time, the side plates 83, 84 and the end flaps 89 form a cylindrical body portion 31 extending upward from the bottom plate 32 of the cardboard box 30, and the perforations 23 are formed so as to divide the body portion 31 into upper and lower parts. ing. The end flaps 89 connected to the side plates 83 and 84 constitute inner flaps, and the end flaps 89 connected to the bottom plate 32 and the top plate 34 constitute outer flaps.

As shown in FIG. 26, the corrugated cardboard box 30 can be opened by breaking the corrugated cardboard along the perforations 23 and dividing the body portion 31 of the corrugated cardboard box 30 into upper and lower parts. At this time, if the breaking line 25 is broken, a finger is put in the part of the breaking line 25, and the part above the perforations 23 of the body part 31 is pulled up, the body part 31 can be smoothly divided. can.

27 and 28 show the blank of the perforated cardboard box for splitting the trunk of the seventh embodiment and the unsealed state of the cardboard box 30 obtained by assembling the blank. Portions corresponding to those in the sixth embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 27 , the perforations 23 of the side plate 83 are arranged closer to the bottom plate 32 than the vertical center of the side plate 83 . The perforation 23 of the side plate 84 is also arranged at a position closer to the bottom plate 32 than the center of the side plate 84 in the vertical direction. An end flap 89 connected to the side plate 83 is formed with a breaking line 90 dividing the end flap 89 into upper and lower parts. The breaking line 90 passes through the vertical central position of the end flap 89 connected to the side plate 83 and extends vertically through the end flap 89 . An end flap 89 connected to the side plate 83 has a V-shaped notch 91 recessed toward the break line 90 at a position where the tip edge of the end flap 89 and the break line 90 intersect. .

Similarly, the end flap 89 connected to the side plate 84 is also formed with a breaking line 90 dividing the end flap 89 into upper and lower parts. The breaking line 90 passes through the vertical center position of the end flap 89 connected to the side plate 84 and extends vertically through the end flap 89 . An end flap 89 connected to the side plate 84 has a V-shaped notch 91 recessed toward the break line 90 at a position where the leading edge of the end flap 89 and the break line 90 intersect. .

The ruled line 88 includes a ruled line 85 between the side plate 83 and the top plate 34 and a break line 92 between the perforations 23 for separating the end flap 89 and the side plate 83 . The crease 88 also has a crease 86 between the side plate 84 and the joint margin 87 and a break line 92 between the perforations 23 for separating the end flap 89 and the side plate 84 .

The cardboard box 30 obtained by assembling the blanks shown in FIG. 27 can be opened by dividing the body portion 31 of the cardboard box 30 into upper and lower parts along the perforations 23 as shown in FIG. This opening operation can be performed, for example, as follows. First, insert a finger into the part of the break line 25 and pull up the part above the perforation 23 of the side plates 83 and 84 to pull the side plate 83 and the end flap 89 connected to the side plate 83 together with the break line 92 and the ruled line. Along with separating along 88, the side plate 84 and the end flap 89 connected to the side plate 84 are also separated along the breaking line 92 and the ruled line 88, and the part above the perforation 23 of the side plates 83, 84 is separated along the ruled line 85. open outward along the Next, the end flap (inner flap) 89 is broken along the breaking line 90 from the notch 91 at the tip edge of the end flap (inner flap) 89 to divide it into upper and lower parts, and the end flap (outer flap) connected to the top plate 34 When the 89 is opened outward along the ruled line 88, as shown in FIG. 28, the trunk portion 31 of the corrugated cardboard box 30 is divided into upper and lower portions and opened.

In this unsealed state, the portion of the body portion 31 on the side of the top plate 34 is in a flat state. That is, since the work of opening the corrugated cardboard box 30 and the work of dismantling the portion of the body portion 31 on the side of the top plate 34 can be performed at the same time, the workability of displaying the products 33 is excellent. In addition, as shown in FIG. 26 of the sixth embodiment, compared to the case where the top plate 34 side portion of the body portion 31 is removed while maintaining the tubular shape, the portion of the body portion 31 on the top plate 34 side is removed from the outer side. Since the product can be removed while being opened, the trunk portion 31 can be removed without interfering with the product 33, and the workability of unsealing is excellent.

In the cardboard box 30 of this embodiment, the perforations 23 of the side plates 83 are arranged closer to the bottom plate 32 than the center of the side plates 83 in the vertical direction, and the perforations 23 of the side plates 84 are also positioned vertically above and below the side plates 84 . Since it is arranged at a position closer to the bottom plate 32 than the center of the direction, when the box is opened as shown in FIG.

1 Front liner 2 Back liner 3 Middle liner 23 Perforation 26 Cut 31 Body 32 Bottom plate 34 Top plate 40 Double facer 43 Perforation knife 44 Perforation forming device 45 Cutoff 68 Blade 69 Cutting edge 70 Cutting edge 71 Cutting edge T Thickness L ₁ Length dimension L ₂ Length dimension W ₁ Width dimension W ₂ Width dimension S Cardboard

Claims (6)

a bottom plate (32);
a cylindrical body (31) extending upward from the bottom plate (32),
The trunk (31) includes a front liner (1) forming an outer peripheral surface of the trunk (31), a back liner (2) forming an inner peripheral surface of the trunk (31), and the front liner (1). ) and a corrugated core (3) sandwiched between said backing liner (2),
A corrugated cardboard box in which perforations (23) for dividing the body (31) into upper and lower parts are formed in the body (31),
The perforations (23) are composed of a large number of cuts (26) penetrating between the back liner (2) side and the front liner (1) side . , in a blank state, it has a configuration that extends vertically from one end to the other end of the blank in a direction perpendicular to the corrugation of the corrugated cardboard ,
The perforations (23) are formed in the midsole (3) so that the difference between the thickness (T) of the corrugated board in the area along the perforations (23) and the maximum thickness of the corrugated board in other areas is less than 1 mm. ) is formed without crushing
A corrugated cardboard box with perforations for splitting the body, characterized by: The perforation (23) is such that the length dimension (L ₁ ) of each of the cuts (26) on the side of the front liner (1) along the direction in which the perforation (23) extends is 2. The corrugated cardboard box with split perforations according to claim 1, wherein the length dimension (L2) of each cut (26) on the side of the back liner ( ₂ ) is smaller than the length (L2). The perforations (23) are such that the width dimension (W1) of each of the cuts (26) on the side of the front liner ( ₁ ) along the direction orthogonal to the extending direction of the perforations (23) is equal to the perforation (23). 3. The trunk portion according to claim 1 or ₂ , wherein the width dimension (W2) of each of the cuts (26) on the side of the back liner (2) along the direction orthogonal to the extending direction of the Cardboard box with perforations for division. In a corrugating machine for manufacturing corrugated board, a corrugated board (S) that is continuous without interruption in the traveling direction is obtained by laminating a front liner (1) to a single-faced corrugated board consisting of a corrugated core (3) and a back liner (2). a double facer (40) forming a
a cut-off (45) disposed downstream of the double facer (40) and cutting the corrugated cardboard (S) into sheets along a direction perpendicular to the traveling direction;
A disc disposed downstream of the double facer (40) and upstream of the cutoff (45), and having a plurality of radially outwardly protruding blades (68) provided on the outer periphery at regular intervals. a perforating device (44) having a perforating knife (43) shaped like;
With the perforation knife (43), a large number of cuts (26) penetrating between the back liner (2) side and the front liner (1) side are cut straight in the advancing direction , that is, in the direction perpendicular to the corrugation of the cardboard. The thickness (T) of the corrugated board (S) in the area along the perforations (23) and the thickness (T) of the corrugated board (S) in the area other than the trunk part dividing perforations (23) arranged in a straight line. forming the medium (3) without crushing so that the difference from the maximum thickness is less than 1 mm;
A method of forming perforations for dividing cardboard. 5. The method of forming perforations for dividing corrugated board according to claim 4, wherein the perforation knife (43) is arranged to cut into the corrugated board (S) from the back liner (2) side. Each of said cutting edges (68) on the outer periphery of said perforation knife (43) includes a radially outer edge cutting edge (69), a rotationally forward edge cutting edge (70) and a rotationally rearward edge cutting edge (69). 6. The method of forming perforations for dividing corrugated cardboard according to claim 4 or 5, wherein a cutting edge (71) is formed on each edge.

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