JP7044302B2 - Manufacturing method for packaging boxes and blanks - Google Patents

Description

The present invention relates to a method for manufacturing a packaging box and a blank .

Patent Document 1 describes a lap round case in which a square tubular peripheral wall is formed by a front side plate, a left side plate, a rear side plate, a right side plate, and an adhesive piece, and an end face opening of the peripheral wall is closed by a flap connected to each side plate. Is disclosed. The front plate is formed with a crease line that extends laterally near the tip of the flap when the flap is folded back. Further, a breaking line extending from the upper end portion to the crease line is formed on the left edge of the front side plate. The right edge of the front side plate is polymerized and bonded to the adhesive piece except for the portion from the upper end to the crease line. When opening this wrap round case, the flap is folded back and polymerized on the front side plate, and then the upper part of the front side plate is tilted outward, so that the upper part of the front side plate is separated by a break line and outward along the crease line. Fold it. As a result, the upper part of the front side plate is greatly opened, so that the contents can be easily taken out.

Japanese Patent No. 3872935

Here, consider a case where the crease line or break line for opening the wrap round case is applied to a so-called A type packaging box. In this case, the crease line will be formed on one side of the packaging box and the break line will be formed along the edge of that side. Type A packaging boxes are stored or transported in a stacked state. When the lower packaging box was subjected to a compressive load, there was a risk that only the side surface on which the crease line was formed would buckle. That is, in some cases, only one side surface is broken at the crease line and bulges outward or dents inward. Then, since the top surface of the packaging box is crushed so as to be tilted, not only the appearance of the packaging box is deteriorated, but also a plurality of stacked packaging boxes 1 may be collapsed. As described above, it has been difficult to simply apply the crease line or break line for opening the wrap round case to the A-type packaging box.

In order to solve the above problems, the present invention provides a method for manufacturing a packaging box and a blank, which can smoothly take out the contents and can be appropriately stacked even if they are crushed by a compressive load.

In order to achieve the above object, the packaging box of the present invention is described by means of a peripheral wall including a pair of end walls and a pair of side walls alternately connected via a first folding curve, and the second folding curve. A flap that is connected to the end of at least one of the side walls of the pair of side walls and that closes at least a part of the opening of the peripheral wall while being bent inside the peripheral wall along the second folding curve. The said on the first fold curve at both ends of the side wall or the side wall to which the flap is connected, at least one reverse fold line formed parallel to the second fold curve by the pair of side walls. It comprises a pair of cutting lines formed between the second fold curve and the reverse fold line, and the flap is folded along the second fold curve so as to overlap the surface of the side wall, and the flap is folded. The side wall to which is continuously provided is bent to the outside of the peripheral wall along the reverse folding line while being cut from the second folding curve toward the reverse folding line along the pair of cutting lines.

In this case, it is preferable that the reverse folding line is formed over the entire circumference of the peripheral wall including the pair of end walls and the pair of side walls.

In this case, it is preferable that the reverse folding lines are formed as a pair in parallel with each other at positions close to each other.

In this case, the peripheral wall is connected to the lower end of at least one of the pair of side walls via the third folding curve, and is bent inward along the third folding curve. The flap further comprises a lower flap that closes at least a portion of the lower surface opening, the flap closing at least a portion of the upper surface opening of the peripheral wall, and the peripheral wall having a plurality of contents contained therein. It is preferable that the total area of the upper surface of the contents is formed so as to occupy 70% or more and less than 100% of the area of the upper surface opening of the peripheral wall.

In this case, it is preferable that the extension dimension from the second folding curve to the tip of the flap is set to be equal to or less than the dimension from the second folding curve to the reverse folding line.

In this case, a pair of auxiliary folding curves formed in a range surrounded by the second folding curve of the side wall to which the flaps are continuously provided, the reverse folding line, and the pair of cutting lines, and the side wall is mountain-folded. It is preferable to have it.

In order to achieve the above-mentioned object, the method for improving the ease of taking out the contents is a peripheral wall including a pair of end walls and a pair of side walls alternately connected via the first folding curve, and a second folding. At least a part of the opening of the peripheral wall is provided in a state of being connected to the end of at least one of the pair of side walls via a curve and bent inward of the peripheral wall along the second folding curve. The closing flap, at least one reverse folding line formed parallel to the second folding curve by the pair of side walls, and the first folding of the side wall to which the flap is connected or both ends of the side wall thereof. A pair of cutting lines formed between the second folding curve and the reverse folding line on the curve, and connecting to the lower end of at least one of the pair of side walls via the third folding curve. A lower flap is provided that closes at least a portion of the lower surface opening of the peripheral wall while being bent inward of the peripheral wall along the third folding curve, and the flap is formed on the second folding curve. The side wall, which is folded back along the surface of the side wall so as to overlap the surface of the side wall, is cut along the pair of cutting lines from the second folding curve toward the reverse folding line, and the reverse folding line is cut. The reverse fold line is formed along the entire circumference of the peripheral wall including the pair of end walls and the pair of side walls, and the flap is an opening on the upper surface of the peripheral wall. In a state where a plurality of contents are housed inside the peripheral wall in a packaging box characterized by closing at least a part of the above, the total area of the upper surface of the plurality of contents is 70% of the area of the upper surface opening of the peripheral wall. The contents are accommodated so as to occupy more than 100%.

According to the present invention, the contents can be smoothly taken out from the packaging box, and the packaging boxes can be appropriately stacked even if the packaging boxes are crushed by a compressive load.

It is a perspective view which shows the packaging box which concerns on one Embodiment of this invention. It is a perspective view which shows the packaging box and a plurality of contents which concerns on one Embodiment of this invention. It is a top view which shows the blank of the packaging box which concerns on one Embodiment of this invention. It is a side view which shows the state in which the packaging box which concerns on one Embodiment of this invention is stacked. It is a perspective view which shows the state which opened the upper flap in the opening process of the packaging box which concerns on one Embodiment of this invention. It is a perspective view which shows the state which opened the packaging box which concerns on one Embodiment of this invention. It is a top view which shows the blank of the packaging box which concerns on 1st modification of 1 Embodiment of this invention. It is a top view which shows the blank of the packaging box which concerns on the 2nd modification of one Embodiment of this invention. It is a perspective view which shows the packaging box which concerns on the 3rd modification of one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawing, "Fr" indicates "front", "Rr" indicates "rear", "L" indicates "left", "R" indicates "right", and "U" indicates "U". "Upper" and "D" indicate "lower". The front-back direction is orthogonal (crosses) to the left-right direction, and the up-down direction is orthogonal (crosses) to the front-back direction and the left-right direction. Although terms indicating directions and positions are used in the present specification, these terms are used for convenience of explanation and do not limit the technical scope of the present invention.

[Overview of packaging box]
The configuration of the packaging box 1 will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view showing a packaging box 1. FIG. 2 is a perspective view showing the packaging box 1 and the plurality of contents M. FIG. 3 is a plan view showing the blank 5 of the packaging box 1.

As shown in FIG. 1, the packaging box 1 is formed in a substantially rectangular parallelepiped shape that is long in the left-right direction. The packaging box 1 is a type A box that is sealed by closing the upper surface and the lower surface of the substantially square cylindrical peripheral wall 1W.

As shown in FIG. 2, a plurality of (for example, 12) contents M are accommodated inside the packaging box 1. In the drawings, each content M is shown as a mere cube, but the content M is, for example, a bundle of a plurality (for example, three) of foam containers for accommodating natto. Further, in the packaging box 1, the contents M are arranged in two rows in the front-rear direction and three rows in the left-right direction, and are stacked in two rows in the vertical direction, and a total of 12 contents M are arranged in a grid. It is arranged in a shape.

The packaging box 1 is formed by assembling the blank 5 shown in FIG. The blank 5 is formed by punching, for example, a sheet of paper corrugated cardboard with a die or the like. The corrugated cardboard sheet is, for example, a double-sided corrugated cardboard sheet in which a front liner 9B and a back liner 9C (see FIG. 2) are bonded to the front and back of a corrugated cardboard 9A. Note that FIG. 3 shows the front liner 9B side (outer surface side of the packaging box 1). In the present specification, the direction parallel to the corrugated cardboard inner shin 9A is referred to as "step direction", and the direction orthogonal to the step direction (middle shin 9A) is referred to as "flow direction". “X” shown in the drawing indicates “step direction”, and “Y” indicates “flow direction”. Further, in the present specification, the terms "top (heaven)", "bottom (bottom)" and similar terms are the top (heaven), bottom (bottom) and the like in the assembled state (assembled state) of the packaging box 1. Refers to a concept similar to.

[blank]
As shown in FIG. 3, the blank 5 includes a pair of end walls 10 and 11, a pair of side walls 12 and 13, a joint piece 14, a pair of upper inner flaps 20 and 21, and a pair of upper outer flaps 22. , 23, a pair of lower inner flaps 30, 31 (lower flaps), and a pair of lower outer flaps 32, 33 (lower flaps).

<End wall, side wall>
The end wall 10, the side wall 12, the end wall 11, the side wall 13, and the passage piece 14 are arranged in a row from one side to the other in this order. The pair of end walls 10 and 11 and the pair of side walls 12 and 13 are alternately connected to each other via a first folding curve L1 extending in the step direction. The end walls 10 and 11 and the side walls 12 and 13 are formed in a substantially rectangular shape having substantially the same dimensions in the step direction. The end walls 10 and 11 are formed to be narrower in the flow direction than the side walls 12 and 13. The joint piece 14 is continuously provided at the other end of the side wall 13 in the flow direction via the first folding curve L1. The side walls 12 and 13 may be formed to be narrower in the flow direction than the end walls 10 and 11. It is more preferable that the end walls 10 and 11 are formed to be narrower in the flow direction than the side walls 12 and 13 because the contents M can be taken out from the wider side walls 12 and 13 side and can be easily taken out.

<Upper inner flap, upper outer flap>
The pair of upper inner flaps 20 and 21 are continuously provided at one end (upper end) in the step direction of the pair of end walls 10 and 11 via a second folding curve L2 extending in the flow direction. The upper inner flaps 20 and 21 are formed in a substantially rectangular shape having substantially the same width as the dimensions of the end walls 10 and 11 in the flow direction. The dimension (extended dimension) of the upper inner flaps 20 and 21 in the step direction is set to less than half of the dimension of the end walls 10 and 11 in the flow direction. The pair of upper and outer flaps 22 and 23 are connected to one end (upper end) of the pair of side walls 12 and 13 in the step direction via the second folding curve L2. The upper outer flaps 22 and 23 are formed in a substantially rectangular shape having substantially the same width as the dimensions of the side walls 12 and 13 in the flow direction. The dimensions (extended dimensions) of the upper outer flaps 22 and 23 in the step direction are substantially the same as the extended dimensions of the upper inner flaps 20 and 21.

<Lower inner flap, lower outer flap>
The pair of lower inner flaps 30 and 31 are continuously provided at the other end (lower end) of the pair of end walls 10 and 11 in the step direction via the third folding curve L3 extending in the flow direction. The pair of lower outer flaps 32, 33 are connected to the other end portion (lower end portion) of the pair of side walls 12, 13 in the step direction via the third folding curve L3. The lower inner flaps 30 and 31 are formed in substantially the same shape as the upper inner flaps 20 and 21, and the lower outer flaps 32 and 33 are formed in substantially the same shape as the upper outer flaps 22 and 23.

The first to third folding curves L1 to L3 are general-purpose ruled lines formed by crushing a corrugated cardboard sheet linearly in the thickness direction from the back liner 9C side. The first to third folding curves L1 to L3 have a function of bending the corrugated cardboard sheet so that the back liner 9C faces inward.

As shown in FIGS. 1 and 2, the pair of end walls 10 and 11 and the pair of side walls 12 and 13 are bent at a substantially right angle along the first folding curve L1, and the joint piece 14 is connected to the inner surface of the end wall 10. (Adhered). Then, a substantially square cylindrical peripheral wall 1W having both upper and lower end surfaces open is formed. As shown in FIG. 1, the upper flaps 20 to 23 substantially close the upper surface opening 1U of the peripheral wall 1W in a state of being bent inward of the peripheral wall 1W along the second folding curve L2. The lower flaps 30 to 33 substantially close the lower surface opening of the peripheral wall 1W in a state of being bent inward of the peripheral wall 1W along the third folding curve L3.

As shown in FIG. 3, the blank 5 is formed with a reverse folding line 40 so that the assembled packaging box 1 is substantially uniformly crushed when a compressive load is applied. Further, the blank 5 is formed with a pair of cutting lines 41 and a pair of auxiliary folding curves 42 in order to smoothly open the assembled packaging box 1 and take out the contents M.

<Reverse polygonal line>
The reverse polygonal line 40 is formed so as to extend continuously in the flow direction to the pair of end walls 10, 11, the pair of side walls 12, 13, and the joint piece 14. That is, the reverse polygonal line 40 is formed over the entire circumference of the peripheral wall 1W including the pair of end walls 10 and 11 and the pair of side walls 12 and 13. The reverse fold line 40 is formed parallel to the second fold curve L2 (or the third fold curve L3) below the center of the height (length in the step direction) of the end walls 10, 11 and the side walls 12, 13 and the like. Has been done. The reverse polygonal line 40 is a reverse ruled line formed by crushing a corrugated cardboard sheet linearly in the thickness direction from the front liner 9B side. The reverse folding line 40 has a function of bending the corrugated cardboard sheet so that the front liner 9B faces inward. It should be noted that the fact that the reverse folding line 40 is formed in parallel with the second folding curve L2 (or the third folding curve L3) does not require that it is exactly parallel, and a deviation of about several degrees is not required. It means to allow.

The extension dimension (S1) from the second folding curve L2 to the tip of the upper flaps 20 to 23 is set to be slightly shorter than the dimension (S2) from the second folding curve L2 to the reverse folding line 40. That is, the upper outer flap 22 is folded along the second folding curve L2 and overlaps the surface of the side wall 12, and its tip does not exceed the reverse folding line 40, and is more preferably located in the vicinity of the reverse folding line 40. It is formed to have an extension size (for example, 2 cm or less). The position near the reverse fold line 40 means that the extension dimension (S1) of the upper flaps 20 to 23 may be set to be equal to or less than the dimension (S2) from the second fold curve L2 to the reverse fold line 40. , It may be the same as the dimension (S2).

<Cut line>
The pair of cutting lines 41 are formed between the second folding curve L2 and the reverse folding line 40 along the first folding curve L1 at both ends of the side wall 12 to which the upper outer flaps 22 are connected. The cutting line 41 is a zipper formed by arranging a plurality of bent cuts at predetermined intervals. The cut is formed by penetrating the blade in the thickness direction of the corrugated cardboard sheet. The cutting line 41 has a function of separating the side wall 12 from the pair of end walls 10 and 11. In addition, in this specification, "on the line" does not require the coincidence with a perfect line, but means, for example, to allow a manufacturing error of about 1 mm.

<Auxiliary folding curve>
The pair of auxiliary folding curves 42 is formed above the reverse folding line 40 of the side wall 12 to which the upper outer flaps 22 are connected. Specifically, the pair of auxiliary folding curves 42 is formed in a range surrounded by the second folding curve L2 between the upper outer flap 22 and the side wall 12, the reverse folding line 40, and the pair of cutting lines 41. The pair of auxiliary folding curves 42 are formed on both sides of the side wall 12 in the flow direction. Specifically, the pair of auxiliary folding curves 42 are obliquely approaching each other from the vicinity of the lower ends of the pair of cutting lines 41 (both ends of the reverse folding line 40) toward the upper and outer flaps 22 side (upper). It is extending. The pair of auxiliary folding curves 42 are general-purpose ruled lines for folding the side wall 12 in a mountain fold.

By the way, the corrugated board sheet is manufactured by executing a laminating step of corrugated board base paper using a device called a corrugated board (not shown). The corrugator attaches the liners 9B and 9C to both sides of the middle shin 9A while advancing the middle shin 9A in the flow direction. Further, the corrugator forms a second folding curve L2, a third folding curve L3 and a reverse folding line 40 extending in the flow direction, and cuts a corrugated cardboard sheet continuous in the flow direction to a predetermined length.

The blank 5 (packaging box 1) is manufactured by processing a corrugated cardboard sheet that has been cut using a device called a flexo folder gluer (not shown). Flexo folder gurua (hereinafter, also referred to as "FFG") is used for printing with flexo ink, ruled lines using cutting tools (cutting blades, push blades, etc.) and punches, grooving and punching, and bonding to corrugated cardboard sheets. It is a device that continuously performs joining using an agent. The FFG forms the upper flaps 20 to 23, the lower flaps 30 to 33 and the like, and also forms the first folding curve L1, the cutting line 41 and the pair of auxiliary folding curves 42 and the like. Further, the FFG bends the end wall 10 and the side wall 13 along the first folding curve L1, adheres the joint piece 14 to the inner surface of the end wall 10 with an adhesive, and puts the package box 1 in a folded state. To manufacture. As the adhesive, for example, a hot melt adhesive, a synthetic resin emulsion adhesive, a double-sided tape, or the like can be used.

[Assembly of packaging box]
Next, a process (assembly work) for assembling the packaging box 1 and the like will be described with reference to FIGS. 1, 2, and 4. FIG. 4 is a side view showing a state in which the packaging boxes 1 are stacked. The packaging box 1 may be manually assembled by an operator, or may be automatically or semi-automatically assembled by a box making machine. Here, as an example, a case where an operator assembles the packaging box 1 will be described.

First, as shown in FIGS. 1 and 2, the operator bends the pair of end walls 10 and 11 and the pair of side walls 12 and 13 at a substantially right angle along the first folding curve L1. Then, the pair of end walls 10 and 11 face each other in the left-right direction, and the pair of side walls 12 and 13 face each other in the front-rear direction. As a result, a peripheral wall 1W having both upper and lower end surfaces open is formed.

Next, the operator bends the lower inner flaps 30 and 31 inward of the peripheral wall 1W along the third folding curve L3, and then applies an adhesive to the surfaces of the lower inner flaps 30 and 31. The operator bends the lower outer flaps 32 and 33 inward of the peripheral wall 1W along the third folding curve L3. As a result, the lower outer flaps 32 and 33 are adhered to the lower inner flaps 30 and 31 via an adhesive to form the bottom surface of the packaging box 1 (see FIG. 1). In this state, there is a gap between the tips of the pair of lower outer flaps 32 and 33.

Next, as shown in FIG. 2, the operator inserts a plurality (12 pieces) of the contents M into the inside of the packaging box 1 from the upper surface opening 1U of the peripheral wall 1W. The area (A1) of the upper surface opening 1U of the peripheral wall 1W is set to be larger than the total area (A2) of the upper surfaces of the plurality of contents M (see the quadrangle shown by the broken line in FIG. 2). Specifically, in the peripheral wall 1W in a state where a plurality of contents M are housed therein, the total area (A2) of the upper surfaces of the plurality of contents M is 70% of the area (A1) of the upper surface opening 1U of the peripheral wall 1W. It is formed so as to occupy more than 100%. In other words, the volume of the packaging box 1 is set to be larger than the total volume of the plurality of contents M, and the outermost peripheral surface of the plurality of contents M housed in the packaging box 1 and the peripheral wall 1W (each wall 10 to 13). There is a slight space (gap) between it and the inner surface of the box. The total area (A2) (or the total volume of the plurality of contents M) on the upper surfaces of the plurality of contents M also includes a slight gap between the adjacent contents M. That is, the total area (A2) of the upper surface of the plurality of contents M is the area of the outermost contour of the plurality of contents M (see the quadrangle shown by the broken line in FIG. 2).

Next, the operator bends the upper inner flaps 20 and 21 inward of the peripheral wall 1W along the second folding curve L2, and then applies an adhesive to the surfaces of the upper inner flaps 20 and 21. The operator bends the upper outer flaps 22 and 23 inward of the peripheral wall 1W along the second folding curve L2. As a result, the upper outer flaps 22 and 23 are adhered to the upper inner flaps 20 and 21 via an adhesive to form the top surface of the packaging box 1 (see FIG. 1). In this state, there is a gap between the tips of the pair of upper and outer flaps 22, 23. Further, in the above description, the outer flaps 22, 23, 32, 33 are adhered to the inner flaps 20, 21, 30, 31, but the present invention is not limited to this, and for example, the outer flaps 22, 23, 32, 33 are attached. Adhesive tape (not shown) may be attached along the tip of the.

With the above, the assembly work of the packaging box 1 is completed. That is, the packaging box 1 is in a sealed state (see FIG. 1).

As shown in FIG. 4, the packaging box 1 containing the contents M is stored or transported in a stacked state. Of the plurality of stacked packaging boxes 1, the lower packaging box 1 receives a compressive load, so that the end walls 10, 11 and the side walls 12, 13 of the lower packaging box 1 may buckle. Specifically, the pair of end walls 10 and 11 and the pair of side walls 12 and 13 may be bent so as to be slightly recessed inward along the reverse folding line 40.

According to this packaging box 1, since the reverse folding line 40 is formed over the entire circumference of the peripheral wall 1W, the pair of end walls 10 and 11 and the pair of side walls 12 and 13 are buckled substantially evenly inward. be able to. That is, since each of the walls 10 to 13 buckles substantially uniformly, the packaging box 1 can be crushed in the vertical direction with the top surface and the bottom surface substantially parallel to each other. As a result, only the end wall 10 (11) and the side wall 12 (13) on one side are prevented from buckling and being crushed so that the top surface of the packaging box 1 is tilted, so that the appearance (appearance) of the packaging box 1 is good. It can be maintained at the same time, and a plurality of packaging boxes 1 can be appropriately stacked.

Further, according to the packaging box 1, since the reverse folding line 40 extends in the flow direction, the reverse folding line 40 can be formed at the same time as the second folding curve L2 or the like in the process of manufacturing the corrugated cardboard sheet by the corrugated board. .. As a result, the reverse folding line 40 can be formed accurately in a short time as compared with the case where the reverse folding line 40 is formed by using FFG in the subsequent process.

[Opening the packaging box]
Next, the opening operation of the packaging box 1 will be described with reference to FIGS. 5 and 6. FIG. 5 is a perspective view showing a state in which the upper flaps 20 to 23 are opened in the process of opening the packaging box 1. FIG. 6 is a perspective view showing a state in which the packaging box 1 is opened.

The sealed packaging box 1 is opened, for example, by opening the top surface and then tilting the upper portion of the side wall 12 outward (forward).

As shown in FIG. 5, the operator opens the pair of upper and outer flaps 22, 23, and then opens the pair of upper and inner flaps 20, 21. Then, the upper surface opening 1U of the peripheral wall 1W is opened, and the upper surfaces of the plurality of contents M are exposed. Further, the operator folds the front upper and outer flaps 22 along the second folding curve L2 so as to overlap the surface of the side wall 12. Then, the tip of the upper outer flap 22 is arranged slightly above the reverse folding line 40.

Next, the operator puts his finger on the upper end portion of the side wall 12 (near the second folding curve L2), and tilts the side wall 12 and the upper outer flap 22 toward the front. Then, as shown in FIG. 6, the upper portion of the side wall 12 is cut from above to below (reverse folding line 40) along the pair of cutting lines 41 while bending and bending along the pair of auxiliary folding curves 42. .. Further, the upper portion of the side wall 12 bends outward (forward) along the reverse polygonal line 40 while being separated from the pair of end walls 10 and 11. When the upper part of the side wall 12 is separated from the pair of end walls 10 and 11, one large opening is formed from the top surface of the packaging box 1 to the upper part of the front surface.

With the above, the opening work of the packaging box 1 is completed. In the above-mentioned opening operation, all the upper flaps 20 to 23 are opened, but the present invention is not limited to this. For example, the pair of upper and outer flaps 20, 21 and the rear upper and outer flaps 23 may be left closed and only the front upper and outer flaps 22 open. Even in this case, the upper part of the side wall 12 can be tilted forward.

In the packaging box 1 according to the present embodiment described above, the side wall 12 to which the upper and outer flaps 22 are connected is cut in reverse along the pair of cutting lines 41 from the second folding curve L2 toward the reverse folding line 40. It is configured to be bent to the outside of the peripheral wall 1W along the folding line 40. According to this configuration, it is possible to continuously open from the upper outer flap 22 to the upper part of the side wall 12. As a result, the packaging box 1 can be easily opened. Further, since a large opening can be made from the top surface of the packaging box 1 to the upper part of the front surface, the contents M can be smoothly taken out.

Further, according to the packaging box 1 according to the present embodiment, since the total area (A2) of the upper surfaces of the plurality of contents M is smaller than the area (A1) of the upper surface opening 1U of the peripheral wall 1W, the peripheral wall 1W and the contents M. A slight gap can be formed between the and. As a result, when a compressive load is applied to the packaging box 1, the pair of side walls 12, 13 and the like can be bent (buckled) inward along the reverse folding line 40.

Further, according to the packaging box 1 according to the present embodiment, since the extension dimension (S1) of the upper outer flap 22 is equal to or less than the dimension (S2) from the second folding curve L2 to the reverse folding line 40, the surface of the side wall 12 is formed. It is possible to prevent the upper and outer flaps 22 folded back from overlapping over the reverse folding line 40. As a result, the side wall 12 on which the upper and outer flaps 22 are overlapped can be rotated (tilted) outward with the reverse folding line 40 as a fulcrum, so that the force applied to cutting the side wall 12 along the pair of cutting lines 41 is saved. can do.

Further, according to the packaging box 1 according to the present embodiment, the side wall 12 can be easily opened by folding and bending the side wall 12 along a pair of auxiliary folding curves 42. As a result, the force applied to the cutting of the side wall 12 along the pair of cutting lines 41 can be saved.

In the packaging box 1 according to the present embodiment, the reverse folding line 40 is formed on the entire circumference of the peripheral wall 1W, but the present invention is not limited to this. As shown in FIG. 7, in the packaging box 1 according to the first modification, the reverse folding line 40 may be formed on at least a pair of side walls 12 and 13 of the walls 10 to 13 constituting the peripheral wall 1W. According to this configuration, the pair of side walls 12 and 13 of the packaging box 1 on which the compressive load is applied can be bent so as to be slightly recessed inward along the reverse folding line 40. As a result, the packaging boxes 1 are prevented from being crushed by strain, and the packaging boxes 1 can be stacked in a stable state without impairing the appearance of the packaging boxes 1. When the reverse folding line 40 is formed only on the pair of side walls 12 and 13, the reverse folding line 40 is formed by using FFG in a step after the manufacturing process of the corrugated cardboard sheet by the corrugated board.

Further, in the packaging box 1 according to the present embodiment (including the first modification), the reverse folding line 40 is formed by one reverse ruled line, but the present invention is not limited to this. As shown in FIG. 8, in the packaging box 1 according to the second modification, two reverse folding lines 40 may be formed in parallel at positions close to each other. According to this configuration, since two reverse folding lines 40 are formed in parallel on the entire circumference (or a pair of side walls 12, 13) of the peripheral wall 1W, the side walls 12, 13 and the like can be easily broken inward. can. This makes it possible to improve the possibility that the packaging box 1 is crushed so that the top surface and the bottom surface are substantially parallel to each other. It should be noted that the fact that two reverse polygonal lines 40 are formed in parallel does not require that they are strictly parallel, but means that an angle deviation of about several degrees is allowed. The reverse folding lines 40 formed in parallel to the adjacent positions may have a distance of 2 cm to 0.1 cm, preferably 1 cm to 0.5 cm. Further, the reverse folding line 40 may be formed in a plurality of pairs by pairing the two formed lines. Further, three or more reverse polygonal lines 40 may be formed at nearby positions. However, since the strength of each wall 10 to 13 decreases as the number of reverse folding lines 40 increases, it is preferable to increase or decrease the number of reverse folding lines 40 according to the required compressive strength of the packaging box 1.

Further, in the packaging box 1 according to the present embodiment (including the first and second modifications), a pair of cutting lines 41 are formed at both ends of the side wall 12, but the present invention is not limited thereto. As shown in FIG. 9, in the packaging box 1 according to the third modification, the pair of cutting lines 41 may be formed at positions shifted from both ends of the side wall 12 toward the center in the left-right direction. Further, the cutting line 41 extends linearly substantially vertically, but the present invention is not limited to this, and the cutting line 41 may extend diagonally or may extend so as to be curved (not shown). Further, the cutting line 41 is a so-called zipper, but the present invention is not limited thereto. The cutting line 41 may be any line for cutting a corrugated cardboard sheet, such as a sewing machine line formed by arranging a plurality of linear cuts at predetermined intervals.

Further, in the packaging box 1 according to the present embodiment (including the first to third modifications; the same applies hereinafter), the cutting line 41 and the auxiliary folding curve 42 are formed so that the upper portion of the front side wall 12 opens. However, the present invention is not limited to this. For example, the cutting line 41 or the auxiliary folding curve 42 may be formed so that the upper portion of the rear side wall 13 opens, or the cutting line 41 or the auxiliary folding curve 42 may be formed so that both the front and rear side walls 12 and 13 open. May (not shown). The auxiliary folding curve 42 may be partially formed in a range surrounded by the second folding curve L2, the reverse folding line 40, and the cutting line 41.
The auxiliary folding curve 42 may be omitted.

Further, in the packaging box 1 according to the present embodiment, the upper outer flaps 22 and 23 are connected to the pair of side walls 12 and 13, but the present invention is not limited to this. For example, one upper outer flap is continuously provided at the upper end of at least one of the pair of side walls 12 and 13, and the upper outer flap is omitted from the upper end of the other side wall 13 (12). May be good (not shown). Similarly, one lower outer flap is continuously provided at the lower end of at least one of the pair of side walls 12 and 13, and the lower outer flap is provided from the lower end of the other side wall 13 (12). It may be omitted (not shown).

Further, in the packaging box 1 according to the present embodiment, the pair of upper and outer flaps 22 and 23 close a part of the upper surface opening 1U of the peripheral wall 1W in a state of being bent inside the peripheral wall 1W, but the present invention is limited to this. Instead, a pair of upper and outer flaps 22, 23 may be formed so as to abut their tips. Similarly, the pair of lower inner flaps 30 and 31 closed a part of the lower surface opening (not shown) of the peripheral wall 1W in a state of being bent inside the peripheral wall 1W, but the pair is not limited to this. The lower outer flaps 32, 33 may be formed so as to abut their tips.

Further, in the packaging box 1 according to the present embodiment, the flaps 20 to 23, 30 to 33 are all formed to have the same extension size, but the present invention is not limited to this, and the flaps may be formed to have different extension dimensions. Even in this case, it is preferable that the pair of upper and outer flaps 22 (23) have an extension dimension that does not exceed the reverse polygonal line 40 when stacked on the side wall 12 (13) that divides the pair of end walls 10 and 11.

Further, in the packaging box 1 according to the present embodiment, the first to third folding curves L1 to L3 are general-purpose ruled lines, but the present invention is not limited to this, and for example, a plurality of cuts are formed on the general-purpose ruled lines at substantially equal intervals. It may be a lead ruled line. Further, similarly to this, the reverse folding line 40 may be a lead ruled line in which a plurality of cuts are formed at substantially equal intervals on the reverse ruled line.

Further, in the packaging box 1 according to the present embodiment, the content M is a container containing natto, but this is an example and is not limited thereto. For example, the content M may be a middle box or the like containing a packaged powder or liquid seasoning, or may be a product other than food. Further, the packaging box 1 contains a substantially cubic (hexahedron-shaped) content M, but the shape of the content M is not limited to this, and a polyhedron or a sphere other than the hexahedron or the like is not limited to this. But it may be. Further, the number and arrangement of the contents M that can be accommodated in the packaging box 1 are not limited to the above, and can be freely changed according to the size and shape of the contents M. Further, the size of the packaging box 1 (the area of the upper surface opening 1U (A1)) and the like can be freely changed according to the number, size, and shape of the contents M.

Further, the packaging box 1 according to the present embodiment is formed of a double-sided corrugated cardboard sheet made of paper, but the present invention is not limited thereto. For example, the corrugated cardboard sheet may be a single-sided corrugated cardboard sheet in which a liner is attached to one side of the corrugated cardboard 9A, or a double-sided corrugated cardboard sheet in which a single-sided corrugated cardboard sheet is attached to a double-sided corrugated cardboard sheet. Further, for example, the packaging box 1 may be made of thick paper, a resin plate, or the like instead of the corrugated cardboard sheet made of paper.

The description of the above embodiment shows one aspect of the method for manufacturing a packaging box and a blank according to the present invention, and the technical scope of the present invention is not limited to the above embodiment.

1 Packaging box 1U Top opening 1W Circumferential wall 10,11 End wall 12,13 Side wall 22,23 Upper outer flap (flap)
30, 31 Lower inner flap (lower flap)
32,33 Lower outer flap (lower flap)
40 Reverse fold line 41 Cut line 42 Auxiliary fold curve L1 1st fold curve L2 2nd fold curve L3 3rd fold curve M Contents

Claims (7)

It is a packaging box (1) formed of a corrugated cardboard sheet in which liners (9B, 9C) are bonded to a middle shin (9A).
Includes a pair of end walls (10, 11) and a pair of side walls (12, 13) that are alternately connected via a first folding curve (L1) extending in the step direction of the corrugated cardboard sheet in the vertical direction. Only, the peripheral wall (1W) with the upper and lower ends open ,
It is connected to the upper end of at least one of the pair of side walls via a second folding curve (L2) extending in the flow direction of the corrugated cardboard sheet in the lateral direction, and is along the second folding curve. A flap (22, 23) that closes at least a part of the upper surface opening (1U) of the peripheral wall while being bent inside the peripheral wall.
It is connected to the lower end of at least one of the pair of side walls via a third folding curve (L3) extending in the flow direction of the corrugated cardboard sheet in the lateral direction, and is connected along the third folding curve. A lower flap (30-33) that closes at least a part of the lower surface opening of the peripheral wall while being bent inside the peripheral wall.
A reverse fold line (40) formed in parallel with the second folding curve , continuous with the pair of end walls and the pair of side walls, and over the entire circumference of the peripheral wall .
A pair of cutting lines (41) formed between the second folding curve and the reverse folding line on the first folding curve at the side wall to which the flaps are continuously provided or at both ends of the side wall thereof. Equipped with
The flap is folded back along the second folding curve so as to overlap the surface of the side wall.
The side wall to which the flaps are continuously provided is bent to the outside of the peripheral wall along the reverse fold line while being cut from the second fold curve toward the reverse fold line along the pair of cut lines. A packaging box featuring. The packaging box according to claim 1, wherein the reverse folding lines are formed in pairs in parallel with each other at positions close to each other. In a state where a plurality of contents (M) are housed in the peripheral wall, the total area (A2) of the upper surfaces of the plurality of contents is 70% or more and 100% of the area of the upper surface opening of the peripheral wall (A1). The packaging box according to claim 1 or 2 , wherein the packaging box is formed so as to occupy less than or equal to. Claim 1 to claim 1, wherein the extension dimension (S1) from the second folding curve to the tip of the flap is set to be equal to or less than the dimension (S2) from the second folding curve to the reverse folding line. The packaging box according to any one of 3 . A pair of auxiliary folding curves (42) formed in a range surrounded by the second folding curve of the side wall to which the flaps are continuously provided, the reverse folding line, and the pair of cutting lines, and causing the side wall to be mountain-folded. The packaging box according to any one of claims 1 to 4 , wherein the packaging box is provided. The method for manufacturing a blank (5) in a packaging box according to any one of claims 1 to 4.
The liner is attached to the corrugated board while advancing the inner shin in the flow direction by a corrugator to form the corrugated cardboard sheet, and the second folding curve extending in the flow direction with respect to the corrugated cardboard sheet, the third. The first step of forming the folding curve and the reverse folding line and cutting the corrugated cardboard sheet continuous in the flow direction to a predetermined length,
With respect to the corrugated cardboard sheet cut to a predetermined length in the first step, the flap and the lower flap are formed by a flexographic folder gluer, and the first folding curve and the cutting line are formed. A method of manufacturing a blank, characterized in that it comprises a process. The method for manufacturing a blank (5) in a packaging box according to claim 5.
The liner is attached to the corrugated board while advancing the inner shin in the flow direction by a corrugator to form the corrugated cardboard sheet, and the second folding curve extending in the flow direction with respect to the corrugated cardboard sheet, the third. The first step of forming the folding curve and the reverse folding line and cutting the corrugated cardboard sheet continuous in the flow direction to a predetermined length,
The flap and the lower flap are formed by a flexographic folder glue on the corrugated cardboard sheet cut to a predetermined length in the first step, and the first folding curve, the cutting line, and the pair of auxiliary foldings are formed. A method for producing a blank, which comprises a second step of forming a curve.

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