JP2010052049A - Blanking die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blanking die for forming a half cut line without causing crush of sheet material. <P>SOLUTION: The blanking die includes a full cut blade 9 with high blade height for making a full cut line penetrating through the surface to the back side of a sheet material S and a half cut blade 11 with low blade height for cutting the sheet material S to the halfway in the thickness direction. A plurality of projection parts 11a are juxtaposedly formed on the half cut blade 11 in the longitudinal direction of the blade, and gradient is formed on the top edge of each projection part 11a, and a recessed part 11b is provided between the adjacent projection parts 11a. As the sheet material is cut from a higher part of the top edge of the projection part 11a in order, the sheet material such as the corrugated fiber paper or the like is not strongly pressed to be crushed, and a joint part is formed in the half cut line by the recessed parts 11b, thus preventing a trouble such as bending at a position except the predetermined position or a trunk expansion on piling when making a box of from the sheet material. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a die-cutting die for punching a sheet material such as cardboard in order to produce a cardboard box having a tear strip for opening.

  In general, as a wrap-round cardboard box for packaging beverage cans, as shown in FIG. 6, a pair of upright plates 2 and a flat plate 3 connected in series via a pair of upper and lower ridge ruled lines 1a are folded and integrated. The peripheral wall is formed in a cylindrical shape by wrapping the can C and joining the passage piece 4 to one of the elevation plates 2, and the elevation plate 2 and the plane plate 3 via a pair of left and right and upper and lower ridge ruled lines 1b. The end plates 5 and 6 extending from the side are bent inward so as to overlap each other, and the overlapping portions are bonded and sealed.

  The opening plate 2 and the end plate 5 of the cardboard box are provided with a tearing strip 7 for opening parallel to the ridge ruled line 1a, and the center portion of the rising plate 2 is provided with an end portion of the tearing strip 7 at the time of opening. A cutting start portion 8 is provided.

  Here, the tear band 7 is formed by two linear cut lines facing each other, and this cut line is generally formed by a liner cut that cuts only the liner on the back side when the corrugator is used to manufacture the corrugated cardboard. However, in order to prevent positional deviation from the cutting start portion 8 to be processed in another process, a half cut line 7A to be processed simultaneously with the cutting start portion 8 by punching when a sheet material as a box material is punched. Sometimes.

  At this time, as shown in FIG. 8, the cutting die D has a full cutting edge 61 for entering the entire cutting line that forms the outline of the sheet material and a full cutting line at the start of the tear band, and a half cutting edge for inserting the half cutting line of the tear band. What provided 62 and the press member 63 which puts a ridge part ruled line is used.

  Here, in the cutting die D, the full cutting blade 61 has a blade height penetrating the front and back of the sheet material S, and the half cutting blade 62 cuts the sheet material S halfway in the thickness direction. Also, the blade height is low, the edge of the blade is straight, and the pressing member 63 is compressed to be lower than the entire cutting blade 61 in order to compress the sheet material S without cutting.

  However, when the die D as described above is used, the sheet material S is crushed without being cut at the initial stage of cutting by the half-cutting blade 62, and at the time of making the box, the sheet material is not the ridge line 1a but the half-cut line 7A. There is a risk that the box will be bent, resulting in poor box making.

  Further, when a plurality of boxes in which the cans C are packaged are stacked, the rising of the vertical plate 2 may occur due to the bending at the half-cut line 7A due to the load, and the aesthetic appearance of the box may be impaired.

  Then, this invention makes it a subject to provide the cutting die which can put a half cut line, without crushing a sheet | seat material.

  As a means for solving the above-mentioned problems, the present invention provides the sheet material with a full cutting line penetrating the front and back sides and a half cutting line cut halfway in the thickness direction. In a cutting die provided with a cutting edge and a half cutting edge with a low cutting edge for inserting a half cutting line, a plurality of convex parts are arranged in the longitudinal direction of the half cutting edge, and a gradient is formed on the edge of each convex part. And the recessed part was provided between the adjacent convex parts.

  Further, in this die cutting, the step between the full cutting edge and the lower end of the convex part of the half cutting edge was set to 0.2 to 0.6 mm corresponding to the corrugated sheet material having a thickness of 2 to 5 mm.

  In the cutting die according to the present invention, when the half-cut line is made, the convex part of the half-cutting blade is sequentially cut from the high part of the blade edge into the sheet material, and the sheet material is not strongly pressed and crushed, and the half-cutting edge is half-cut When the connecting portion is formed on the wire and the box is made from the sheet material, it is difficult to bend at a position other than the predetermined position, the occurrence of defective box making can be prevented, and the swelling at the time of stacking can also be prevented.

  Also, when opening the box with the half cut line of the tear strip in this punching, if the tear strip is pulled from its start, the corrugated cardboard is cut along the half cut line, and the tear strip is not broken in the middle and easily Can be opened.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a corrugated cardboard box in which a half-cut line of a tear band is put in accordance with the present invention will be described with reference to the accompanying drawings.

  This cardboard box is a wrap round type used for packaging beverage cans, and is formed from a cardboard sheet material S shown in FIG. In this sheet material S, a pair of elevation plates 2 and plane plates 3 are alternately arranged via ridge ruled lines 1a, and a passage piece 4 is arranged continuously on one elevation plate 2 via ridge ruled lines 1a. Has been. End plates 5 and 6 are connected to both ends of the upright plate 2 and the flat plate 3 via ridge ruled lines 1b, respectively.

  The elevating plate 2 and the end plate 5 are provided with a tear strip 7 for opening parallel to the ridge ruled line 1a, and the center portion of the elevating plate 2 is a cut start portion 8 for gripping the end portion of the tear strip 7 when opened. Is provided.

  Here, the tear band 7 in the elevation plate 2 is formed by two symmetric half cut lines 7A, and the half cut line 7A includes a half cut line 7a in which the sheet material S is cut from the back side to the middle in the thickness direction. A plurality of connecting portions 7b without cuts are alternately formed.

  The cut start portion 8 is formed by putting all the cut lines 8a penetrating the front and back of the sheet material S into a deformed H shape.

  A die cutter as shown in FIG. 2 is equipped with a die cutter for manufacturing the cardboard box. The punching die D is provided with all cutting edges 9 for punching so as to form the contour of the sheet material S, and a ridge ruled line 1a is placed at the boundary between the vertical plate 2 and the flat plate 3, and the vertical plate 2 and the flat plate 3 A pressing member 10 for placing the ridge ruled line 1b is provided at each boundary with the end plates 5 and 6.

  Further, the cutting die D is provided with a half cutting edge 11 for inserting the half cutting line 7A of the tear band 7 in parallel with the pressing member 10 for inserting the ridge line ruled line 1a, and subsequently, the whole cutting line 8a of the cutting start part 8 is provided. All cutting blades 9 are provided at a portion corresponding to the central portion of the upright plate 2.

  Here, the half cutting edge 11 is provided with a plurality of convex portions 11a forming a half cut line 7a of the half cutting line 7A at a predetermined interval in the length direction between the adjacent convex portions 11a. Are provided with recesses 11b forming the connecting portions 7b of the half-cut line 7A at equal intervals.

  Moreover, as shown in FIG. 3, the edge of each convex part 11a is provided with a gradient such that the central part has a high mountain shape.

  Here, when punching out the sheet material S having a thickness of 2 to 5 mm, the step α between the full cutting edge 9 and the upper end of the convex portion 11a of the half cutting edge 11 is 0.2 to 0.5 mm, and the full cutting edge 9 and the half cutting edge. 11 is preferably set to 0.4 to 0.8 mm, and the width γ of the recess 11 b is set to 0.2 to 0.9 mm.

  When the sheet material S is punched from the back side (lower side) with the above-described die D, as shown in FIGS. 3 and 4, the entire cutting blade 9 is completely cut and pressed so as to penetrate the sheet material S. The member 10 presses the sheet material S, and the convex portion 11a of the half-cutting blade 11 sequentially cuts the sheet material S from a portion having a high cutting edge. For this reason, at the initial stage of cutting, the sheet material S is hardly pressed and crushed by the half cutting edge 11.

  Moreover, even if the cutting edge of the full cutting edge 9 is worn down and the blade height is lowered due to long-term use, the cutting of the full cutting edge 9 and the half cutting edge 11 is caused by the gradient provided on the convex portion 11a of the half cutting edge 11. The balance does not change greatly.

  Note that the edge of the convex portion 11a of the half-cutting blade 11 has a shape inclined from one side to the other as shown in FIG. 5A, and the central portion swells in an arc shape as shown in FIG. 5B. As shown in FIG. 5 (c), the protruding portion 11a sequentially cuts the sheet material S from the portion with the high cutting edge, as shown in FIG. 5 (c). The effect of can be obtained.

  Such a half cutting edge 11 can be easily manufactured by a wire-cut electric discharge machine, and can be manufactured not only for a flat plate die cutter but also for a rotary die cutter.

  Now, when a beverage can is packaged by forming a box with the sheet material S punched out as described above, a wrap round caser is used, as shown in FIG. 6, along each ridge line 1a. A pair of upright plates 2 and flat plates 3 are bent, wrapped in cans C, and joined to one of the upright plates 2 to form a peripheral wall in a cylindrical shape, and end plates 5 and 6 are It is folded inward along the ridge ruled line 1b so as to overlap each other, and the overlapping portion is bonded and sealed.

  At the time of making the box, in the above corrugated cardboard box, the corrugated cardboard is not crushed at the half cut line 7A portion of the tear strip 7, and the connecting portion 7b is formed between the adjacent half cut lines 7a. As shown in FIG. 3, the upright plate 2 is less likely to be bent inward at the half-cut line 7A, and is accurately bent along the ridge ruled line 1a with the flat plate 3, so that it is possible to prevent the occurrence of defective box making.

  Further, when the sheet material S is punched, since the half cut line 7A of the tear strip 7 and the entire cut line 8a of the start portion 8 are processed so as to be simultaneously put in the same die, the positional relationship between them does not shift. Compared with the manufacturing method in which all the cutting lines 8a are inserted by a die cutter in a separate process after the liner cut by a conventional corrugator, the defect rate can be greatly reduced.

  When the tear strip 7 is pulled from the cut start portion 8 at the time of opening, the corrugated cardboard is cut along the half-cut line 7A without tearing and becoming unopenable like a line cut with a liner cut. Can be opened.

  On the other hand, when a plurality of cardboard boxes are stacked in the state of packaging in a physical distribution process, a large load is applied to the lower cardboard box. Even in such a state, the cardboard is crushed by the half-cut line 7A. Since it is not done or has the connecting portion 7b, the buckling of the elevation plate 2 at the half-cut line 7A is suppressed and the swelling of the trunk is prevented, so that the appearance of the cardboard box is not impaired. .

  In each of the above embodiments, the case where a straight half-cut line is put as a tear band in a cardboard box is illustrated, but even when a wavy half-cut line is put, if a half-cutting blade as described above is used, It is possible to effectively prevent the buckling strength from being lowered, and it is possible to improve the effect of preventing the occurrence of boxing defects and the swelling of the body during stacking.

  Further, not only a sheet material made of corrugated cardboard but also a sheet material made of a single paper such as paperboard or a plastic sheet material such as polypropylene, a half-cut line can be made with the same half-cutting blade.

  Furthermore, this half-cutting blade is not only applied to the half-cut line of the tear band for the purpose of resisting buckling while ensuring cutability, as in the above embodiment, but also in a folding bottom assembly, etc. It can also be used when a half-cut line is made as a ruled line that is bent in the direction opposite to the cut side.

The reverse view which shows the sheet | seat material of the cardboard box which uses the cutting die concerning this invention The perspective view which shows the principal part of a die cutting same as the above Schematic sectional view showing the cutting process into the sheet material by the same die cutting Schematic sectional view showing the state of cutting into the sheet material by the same die cutting Schematic cross-sectional view showing various forms of the half cutting blade The perspective view which shows the assembly sealing state of a cardboard box Partial perspective view showing the box making process Schematic cross-sectional view showing the process of cutting into sheet material by conventional die cutting

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Edge part ruled line 2 Elevation board 3 Plane board 4 Passage piece 5,6 End plate 7 Tear strip 7A Half cut line 7a Half cut line 7b Connection part 8 Cutting part 8a Full cutting line 9 Full cutting edge 10 Pressing member 11 Half cutting edge 11a Convex part 11b Concave part D Cutting die S Sheet material

Claims (2)

  In order to put a full cut line penetrating the front and back in the sheet material and a half cut line that is cut halfway in the thickness direction, a full cutting edge (9) with a high blade height for entering the full cutting line and a blade height for inserting the half cutting line In the punching die provided with a low half cutting edge (11), the half cutting edge (11) is provided with a plurality of convex portions (11a) arranged in the length direction of the blade, and a slope is formed on the edge of each convex portion (11a). And a concave portion (11b) is provided between adjacent convex portions (11a).   2. The die according to claim 1, wherein the step [alpha] between the full cutting edge (9) and the lower end of the convex portion (11a) of the half cutting edge (11) is set to 0.2 to 0.6 mm.

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