JP6960019B2 - Packaging bag and its preparation method and sheet-like material for preparation - Google Patents

Description

The present invention relates to a packaging bag made by folding a single sheet-shaped material, a method for making the same, and a sheet-shaped material for making a packaging bag used for making the bag.

Packaging bags are used in all aspects of daily life as simple packaging of goods for sale, temporary storage bags for take-out, etc. at retail stores such as supermarkets, convenience stores, greengrocers, and fish stores. In the past, newspapers and other papers were commonly used as packaging bags, such as those that were rolled into an inverted cone or made into a bag by pasting appropriate parts. However, with the recent development of synthetic resins such as polyethylene, polypropylene, and polyvinyl chloride, most of these packaging bags have been replaced by synthetic resin bags, except for some paper bags. As a result, the major portion of domestic synthetic resin consumption, which now amounts to millions of tons per year, is now occupied by these simple packaging and temporary storage bags for take-out. Synthetic resin materials are excellent in terms of flexibility, durability, price, etc., but since they are made from petroleum resources, there are concerns about future resource depletion. In addition, synthetic resins have the disadvantage that they do not decompose naturally, and environmental pollution due to the mass disposal of synthetic resin products and deterioration of the landscape due to debris washed ashore on the coast have become serious environmental problems worldwide. Against this background, packaging bags used for take-out of products at retail stores such as supermarkets and convenience stores are required to be converted to materials that can be reused or have a small environmental load at the time of disposal.

From the viewpoint of having a small environmental load at the time of disposal, paper and cloth that have been conventionally used for simple packaging and temporary storage of products have some advantages. However, even for materials such as paper and cloth, if these are newly produced to produce temporary storage bags for simple packaging and take-out, it is inevitable that a certain amount of energy and time and effort will be required. When paper is used as a material, if a paper bag generally used in a retail store such as a department store is to be manufactured, for example, as disclosed in Non-Patent Document 1 and Non-Patent Document 2, the adhesive It has the disadvantage that it is indispensable to use and it takes time to manufacture, and even when cloth is used as a material, work such as sewing is required.

On the other hand, a method of making a packaging bag from a sheet of paper without using an adhesive has also been proposed. For example, in Non-Patent Document 3, a sheet of paper is folded and a bag is folded using an origami method. How to create is disclosed. However, the bag disclosed in Non-Patent Document 3 is accompanied by two folds on one side of the bag with the end faces of the sheet-like material exposed on the outside, so that the folds hold the bag. It has the disadvantage that it is easily caught by protrusions such as fingers and other articles, and is not sufficiently satisfactory in terms of ease of gripping, safety, and durability.

The present inventor has previously come up with a method of making a card case or a book cover by folding a sheet of material by an origami method without using an adhesive, and disclosed it in Patent Document 1. According to this method, it is not necessary to use newly manufactured sheet-like materials for card cases or book covers, and anyone can use familiar sheet-like materials such as newspapers, advertising leaflets, and wrapping papers. It is very convenient and resource-saving because you can easily make a card case or book cover. However, these are for accommodating cards and covering books, and are not packaging bags for simple packaging of products or temporary storage for take-out.

Japanese Patent No. 6437495

"Let's make a" bag "to put gifts in origami! , [Оnline], March 12, 2019 Search, Internet, <URL: https://оrigamiblоg.infо/2198> "Make a wrapping bag with origami paper and make a small gift of sweets ♪ Easy way to fold a cute paper bag", [оnline], search on March 12, 2019, Internet, <URL: https: // wrapping-adviser. net / оrigami-kakusоkоbag /> "How to fold an origami" bag "", [оnline], search on March 8, 2019, Internet, <URL: https://оrigamijapan.net/jp/bag/>

The present invention is intended to solve the problems of the conventional packaging bag as described above, and it does not require an adhesive or the like to be produced, and anyone can easily produce it using familiar materials. It is an object of the present invention to provide a packaging bag which can be used and has excellent safety and durability, a method for producing the packaging bag, and a sheet-like material for producing the packaging bag used for the production thereof.

As a result of repeated diligent trial and error in order to solve the above problems, the present inventor folds the lower end portion of one sheet-like material to form a folded portion at the lower portion of the sheet, and then forms the left and right end portions of the sheet-like material. , Both are valley-folded or mountain-folded, and the lower part of either of the left and right ends that are both valley-folded or mountain-folded is inserted into the other lower part and engaged with each other to form a tubular body. The lower part of the portion is valley-folded or mountain-folded toward the upper part, and the upper part of the tubular portion is valley-folded or mountain-folded toward the lower part on the same side as the lower part of the tubular body. We have found that it is possible to create a packaging bag with excellent safety and durability relatively easily and without using an adhesive by inserting it into the.

That is, the present invention is a packaging bag made by folding a sheet-like material.
A lower folded portion γ2 formed by valley-folding or mountain-folding the lower end portion of the sheet-shaped material along a straight lower horizontal fold line, and a lower folded portion γ2.
With the lower folded portion γ2 formed, the right portion of the sheet-shaped material is located on the right side of the center in the left-right direction of the sheet-shaped material and along the right vertical fold line orthogonal to the lower horizontal fold line. 2nd side folded part γ4 formed by valley folding or mountain folding, and
With the lower folded portion γ2 formed, the lower folded portion γ2 is located on the left side from the right vertical fold line by a length substantially equal to or longer than the lateral length of the second side folded portion γ4, and the lower horizontal fold is formed. Along the left vertical fold line orthogonal to the line, the left side portion of the sheet-like material is formed by valley fold or mountain fold on the same side as the second side folded portion γ4, and the tip thereof is formed by the second side. A first side folded portion γ3 located on the right side of the tip of the folded portion γ4 is provided.
The second side folded portion γ4 and the first side folded portion γ3 are such that the lower end portion of the tip of the first side folded portion γ3 is located at the lower end portion of the tip of the second side folded portion γ4. The lower end of the tip of the second side folded portion γ4 is located at the lower end of the tip of the first side folded portion γ3, or is inserted into the gap formed inside the lower folded portion γ2. By being inserted into the gap formed inside the lower folded portion γ2, they engage with each other, and the first side folded portion γ3, the second side folded portion γ4, the right vertical folding line and the said A tubular body surrounded by the sheet-like material in the portion sandwiched between the left vertical fold lines is formed.
Further, in the state where the tubular body is formed, the lower portion of the tubular body is located below the center in the vertical direction of the tubular body, and the bottom of the bag is laterally folded parallel to the lower horizontal fold line. The folded portion γ5 of the bag body formed by folding valleys or mountains along the line, and
With the bag body folded portion γ5 formed, the upper part of the tubular body is upward by a length substantially equal to or longer than the vertical length of the bag body folded portion γ5 from the bag bottom horizontal fold line. It is formed by a valley fold or a mountain fold on the same side as the bag body folding portion γ5 along the bag upper horizontal folding line parallel to the lower horizontal folding line, and the lower tip thereof is formed by folding the bag body. A bag upper folded portion γ6 located below the upper tip of the portion γ5 is provided.
A packaging bag including a bag-shaped portion formed inside the bag body folded portion γ5 by inserting the tip end portion of the bag upper folded portion γ6 into the tubular body of the bag body folded portion γ5. By providing the above problem.

Further, the present invention is a method for producing a packaging bag by folding a sheet-like material, and solves the above-mentioned problems by providing a method for producing a packaging bag including the following steps (A) to (G). Is a thing;
(A) A step of forming a lower folded portion γ2 by making a valley fold or a mountain fold along a straight lower horizontal fold line at the lower end portion of the sheet-shaped material.
(B) The sheet-like material is located on the right side of the center of the sheet-like material in the left-right direction with the lower folded portion γ2 formed, and is located along the right vertical fold line orthogonal to the lower horizontal fold line. A step of forming a second side folded portion γ4 by folding a valley or a mountain on the right side of the
(C) In a state where the lower folded portion γ2 is formed, the lower folded portion γ2 is located on the left side from the right vertical folding line by a length substantially equal to or longer than the lateral length of the second side folded portion γ4. Along the left vertical fold line orthogonal to the lower horizontal fold line, the left side portion of the sheet-like material is valley-folded or mountain-folded to the same side as the second side fold-back portion γ4 to form a first side fold-back portion γ3. The position of the left vertical fold line is selected so that the tip of the first side fold-back portion γ3 to be formed is located on the right side of the tip of the second side fold-back portion γ4. Step (D) The lower end of the tip of the first side folded portion γ3 is within the gap formed inside the lower folded portion γ2 located at the lower end of the tip of the second side folded portion γ4. The lower end of the tip of the second side folded portion γ4 is inserted into the gap formed inside the lower folded portion γ2 located at the lower end of the tip of the first side folded portion γ3. By inserting the second side folded portion γ4 and the first side folded portion γ3 into each other, the first side folded portion γ3, the second side folded portion γ4, and the right vertical portion are engaged with each other. A step of forming a tubular body surrounded by the sheet-like material in a portion sandwiched between the fold line and the left vertical fold line.
(E) With the tubular body formed, the lower portion of the tubular body is located below the center of the tubular body in the vertical direction, and the side of the bottom of the bag parallel to the lower horizontal fold line. A step of forming a folded portion γ5 of a bag body by folding a valley or a mountain along a folding line.
(F) With the bag body folded portion γ5 formed, the length of the upper portion of the tubular body is substantially equal to or longer than the vertical length of the bag body folded portion γ5 from the bag bottom horizontal fold line. The bag upper folded portion γ6 is formed by making a valley fold or a mountain fold on the same side as the bag main body folded portion γ5 along the bag upper horizontal fold line which is located on the upper side and is parallel to the lower horizontal fold line. In the step, the position of the bag upper horizontal fold line is selected so that the lower tip of the bag upper folded portion γ6 to be formed is located below the upper tip of the bag body folded portion γ5. Process,
(G) A step of forming a bag-shaped portion inside the bag body folded portion γ5 by inserting the tip end portion of the bag upper folded portion γ6 into the tubular body of the bag body folded portion γ5.

The lower folded portion γ2 may be formed by folding the lower end portion of the sheet-like material in a valley along a straight lower horizontal fold line, or by folding a mountain. Similarly, the second side folded portion γ4 and the first side folded portion γ3 fold the right side portion and the left side portion of the sheet-like material together along the right vertical fold line or the left vertical fold line, respectively. It may be formed by folding it together, or it may be formed by folding it together.

However, the lower folded portion γ2 is hidden inside the second side folded portion γ4 and the first side folded portion γ3 so as to be inconspicuous in appearance, and unnecessary interference with human hands or articles to be taken in and out is prevented. From the viewpoint of avoiding and improving safety and durability, the direction of the valley fold or the mountain fold when forming the lower folded portion γ2, and the second side folded portion γ4 and the first side folded portion γ3 It is preferable to align them so that they are aligned in the same direction as the valley fold or mountain fold when forming. That is, when the lower folded portion γ2 is formed by folding the lower end portion of the sheet-like material in a valley along the lower horizontal folding line, the second side folded portion γ4 and the first side folded portion γ3 are formed. , It is preferable that the right side portion and the left side portion of the sheet-like material are formed by valley folding together along the right vertical fold line or the left vertical fold line, respectively, and conversely, the lower folded portion γ2 is formed by mountain fold. If this is the case, it is preferable that the second side folded portion γ4 and the first side folded portion γ3 are also formed by mountain folding.

On the other hand, if the strength aspect is emphasized, the direction of the valley fold or the mountain fold when forming the lower folded portion γ2 and the second side folded portion γ4 and the first side folded portion γ3 are formed. It is preferable that the direction of the valley fold or the mountain fold is opposite to that of the fold. That is, when the lower folded portion γ2 is formed by folding the lower end portion of the sheet-like material in a valley along the lower horizontal folding line, the second side folded portion γ4 and the first side folded portion γ3 are formed. , It is preferable that the right side portion and the left side portion of the sheet-like material are formed by mountain folds together along the right vertical fold line or the left vertical fold line, respectively, and conversely, the lower folded portion γ2 is formed by mountain folds. When this is done, it is preferable that the second side folded portion γ4 and the first side folded portion γ3 are formed by valley folding.

Further, in the packaging bag and the method for producing the packaging bag according to the present invention, the second side folded portion γ4 and the first side folded portion γ3 are in the form of sheets located at portions facing the second side folded portion γ4. A material, or a sheet-like material located at a portion facing the second side folded portion γ4 and the first side folded portion γ3, in other words, a portion sandwiched between the right vertical fold line and the left vertical fold line. A tubular body is formed together with the sheet-like material of. Then, in this tubular body, the lower end portion of the tip of the first side folded portion γ3 is inserted into the gap formed inside the lower folded portion γ2 located at the lower end portion of the tip of the second side folded portion γ4. Or conversely, the lower end of the tip of the second side folded portion γ4 is in the gap formed inside the lower folded portion γ2 located at the lower end of the tip of the first side folded portion γ3. It is inserted and formed by engaging the first side folded portion γ3 and the second side folded portion γ4 with each other. Moreover, the lower part of the formed tubular body is folded toward the upper part to form the bag body folded portion γ5, and the upper part of the tubular body is folded toward the lower part to form the bag upper folded portion γ6. A packaging bag is formed by inserting the tip of the bag upper folded portion γ6 into the upper opening of the bag body folded portion γ5. Therefore, the packaging bag according to the present invention is strong against the force from the inside of the bag that tries to spread the bag outward, and even if various articles are stored inside the bag, the packaging bag is unnecessarily. It has the advantage of excellent durability without fear of collapsing or being disturbed. At this time, if the second side folded portion γ4 and the first side folded portion γ3 are folded in the direction opposite to the folding direction forming the lower folded portion γ2, the lower folded portion γ2 A portion appears on the outside of the packaging bag to be finally created, that is, on the outside of the bag body folded portion γ5, and the upper opening of the bag body folded portion γ5 and the tip of the bag upper folded portion γ6 inserted therein. The advantage is that the engagement is tighter and the opening of the packaging bag is stronger.

In the packaging bag of the present invention, prior to the formation of the lower folded portion γ2, the right end portion or the left end portion of the sheet-like material is valley-folded or mountain-folded along an auxiliary vertical fold line orthogonal to the lower horizontal fold line. Auxiliary folded-back portion γ1 may be formed. In that case, the lower folded portion γ2 is formed by making a valley fold or a mountain fold along the lower horizontal fold line at the lower end portion of the sheet-like material with the auxiliary folded portion γ1 formed. .. When the auxiliary folded portion γ1 is formed, the end portion of the sheet-like material on the side where the auxiliary folded portion γ1 is formed has a double structure and is reinforced, so that there is an advantage that the durability of the packaging bag is further enhanced. can get. The folding direction of the auxiliary folding portion γ1 may be the same as or opposite to the folding direction of the lower folding portion γ2. The auxiliary folded portion γ1 may be provided on both the left and right sides of the sheet-shaped material.

Further, in the present invention, the above-mentioned lower horizontal fold line, right vertical fold line, left vertical fold line, bag bottom horizontal fold line, and bag upper horizontal fold line are described at predetermined positions inside the quadrangle. The above-mentioned problems are solved by providing a sheet-like material for making a bag. In the sheet-like material for making a packaging bag, in addition to the above-mentioned lines, an auxiliary vertical fold line may be described at a predetermined position inside the quadrangle.

The sheet-like material for making a packaging bag according to the present invention may be a quadrangle itself, and a necessary fold line may be described at a predetermined position inside the quadrangular material. Further, a quadrangular section may be set inside the sheet-like material having an arbitrary shape, and a necessary fold line may be described at a predetermined position in the quadrangular section. In the latter case, when creating the packaging bag, the quadrangular portion on which the fold line is described is cut out from the sheet-like material having the arbitrary shape, or the unnecessary portion of the sheet-like material having the arbitrary shape is folded to obtain the above. A quadrangular sheet-like material on which fold lines are described may be used, or a predetermined mountain fold valley fold may be made to create a packaging bag while leaving the portion protruding from the quadrangle as it is.

In the present invention, the sheet-like material used for producing the packaging bag may be made of any material as long as it can be folded in a mountain fold and / or in a valley fold. For example, it may be a paper such as Japanese paper or Western paper, or a cloth such as a woven cloth or a non-woven fabric, and may be a synthetic resin sheet. Wrapping paper or the like may be used, and if there is a sheet-like material on which the necessary fold lines are displayed in advance, it may be used.

Further, in order to increase the durability of the packaging bag to be produced and prevent the adhesion of dirt, a part or all of the sheet-like material may be laminated with a thin resin film. In addition, taking into consideration the finished state, print, paste, sew, embroider, thermocompression-bond, etc. at appropriate positions on the sheet-like material, and use appropriate methods such as letters, pictures, characters, patterns, figures, symbols, Colors, photographs, etc. may be pasted to decorate.

Furthermore, mountain folds, valley folds, or appropriate parts of the sheet-like material to be inserted are fixed with an adhesive such as glue or a stapler to increase the strength of the packaging bag and prevent the shape from collapsing. You may do so.

According to the packaging bag of the present invention and the method for producing the same, a packaging bag having excellent safety and durability is adhered using a sheet-like material such as paper or cloth that is easily available to anyone. The origami method has the advantage that anyone can easily produce it without using an agent or the like. In addition, the created packaging bag can be easily disassembled and disposed of when it is no longer needed.

Further, according to the sheet-like material for making a packaging bag of the present invention, necessary fold lines are described in advance at predetermined positions of the sheet-like material, so that the sheet-like material can be simply folded according to those instructions. , The advantage that the packaging bag can be easily made can be obtained.

It is a development view of an example of the packaging bag which concerns on this invention. It is a top view which shows an example of the sheet-like material used for making the packaging bag which concerns on this invention. It is a bottom view which shows an example of the sheet-like material used for making the packaging bag which concerns on this invention. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a partially enlarged view of FIG. It is a figure which shows another example of the procedure for making a packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a partially enlarged view of FIG. It is a figure which shows another example of the procedure for making a packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the manufacturing procedure of the packaging bag. It is a figure which shows the use example of the packaging bag which concerns on this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings, but it goes without saying that the present invention is not limited to the illustrated ones.

FIG. 1 is a developed view of an example of a packaging bag according to the present invention. In FIG. 1, 1 is a sheet-like material, T is an upper side of the sheet-like material 1, B is a lower side, R is a right side, and L is a left side. In this example, the sheet-like material 1 has a rectangular shape, the upper side T and the lower side B are equal in length and parallel to each other, the right side R and the left side L are equal in length and parallel to each other, and the upper side T and the lower side B are parallel to each other. , The right side R and the left side L are orthogonal to each other. Further, the lengths of the upper side T and the lower side B are longer than the lengths of the right side R and the left side L. However, the planar shape of the sheet-like material 1 is not necessarily limited to a horizontally long rectangle, and may be a vertically long rectangle or a square. Further, the absolute values of the lengths of the upper side T, the lower side B, the right side R, and the left side L are not particularly limited, and can be appropriately changed according to the size and shape of the packaging bag to be produced.

Further, the sheet-like material 1 may have a portion protruding outside the quadrangle surrounded by the upper side T, the lower side B, the right side R, and the left side L. In this case, when creating the packaging bag, the protruding portion is cut along the upper side T, the lower side B, the right side R, or the left side L, or along the upper side T, the lower side B, the right side R, or the left side L. The sheet-like material 1 may be folded back to form a square shape. Alternatively, the packaging bag according to the present invention may be prepared by performing various folding described later while keeping the protruding portion as it is.

In FIG. 1, the line shown by the broken line on the sheet-shaped material 1 is a crease, and the broken line shown by 2 in the figure is formed when the sheet-shaped material 1 is folded along the auxiliary vertical fold line 2v described later. The creases made and the broken lines indicated by 3 and 4 are creases formed when the sheet-like material 1 is folded along the right vertical fold line 3v and the left vertical fold line 4v, which will be described later. Similarly, the broken lines indicated by 5, 6 and 7 are formed when the sheet-like material 1 is folded along the lower horizontal fold line 5h, the bag bottom horizontal fold line 6h, and the bag upper horizontal fold line 7h, which will be described later. It is a crease.

In this example, the creases 2, 3 and 4 are parallel to each other and are also parallel to the upper side T and the lower side B of the sheet-like material 1. Further, the creases 5, 6 and 7 are parallel to each other and are also parallel to the right side R and the left side L of the sheet-like material 1. This is because the auxiliary vertical fold line 2v, the right vertical fold line 3v, and the left vertical fold line 4v corresponding to the creases are parallel to each other, and the right side R and the left side L are also parallel, the lower horizontal fold line 5h, and the bottom of the bag. This means that the horizontal fold line 6h and the bag upper horizontal fold line 7h are parallel to each other and are also parallel to the upper side T and the lower side B.

In FIG. 1, D1 to D8 represent the length of each portion. That is, D1 is the length from the upper side T to the crease 7 (that is, the length from the upper side T to the bag upper horizontal fold line 7h), and D2 is the length from the fold 7 to the crease 6 (that is, the upper part of the bag). The length from the horizontal fold line 7h to the bag bottom horizontal fold line 6h), D3 is the length from the fold mark 6 to the fold mark 5 (that is, the length from the bag bottom horizontal fold line 6h to the lower horizontal fold line 5h) , D4 represents the length from the crease 5 to the lower side B (that is, the length from the lower horizontal fold line 5h to the lower side B).

Similarly, D5 is the length from the left side L to the crease 4 (that is, the length from the left side L to the left vertical fold line 4v), and D6 is the length from the crease 4 to the crease 3 (that is, the left vertical). The length from the fold line 4v to the right vertical fold line 3v), D7 is the length from the fold mark 3 to the crease 2 (that is, the length from the right vertical fold line 3v to the auxiliary vertical fold line 2v), and D8 is It represents the length from the fold mark 2 to the right side R (that is, the length from the auxiliary vertical fold line 2v to the right side R).

The lengths of D1 to D8 are not particularly limited as long as the packaging bag according to the present invention can be prepared from the sheet-like material 1, but D6 is equal to D7 or slightly longer than D7. It is preferable that D2 is equal to D3 or slightly longer than D3 and substantially equal to D3. Further, it is preferable that D1 and D4 are shorter than D3, and D5 and D8 are shorter than D7.

FIG. 2 is a plan view of the sheet-shaped material for producing a packaging bag according to the present invention, and corresponds to the front side of the sheet-shaped material. In FIG. 2, 1 is a sheet-like material, 2v is an auxiliary vertical fold line, 3v is a right vertical fold line, 4v is a left vertical fold line, and 5h is a lower horizontal fold line. As explained earlier with reference to FIG. 1, the length (that is, the distance) from the right side R to the auxiliary vertical fold line 2v is D8, and the length (distance) from the auxiliary vertical fold line 2v to the right vertical fold line 3v is. D7, the length (distance) from the right vertical fold line 3v to the left vertical fold line 4v is D6, and the length (distance) from the left vertical fold line 4v to the left side L is D5. Further, the length (distance) from the lower horizontal fold line 5h to the lower side B is D4. Other fold lines do not appear in the plan view of the sheet-like material 1.

FIG. 3 is a bottom view of the sheet-like material 1 shown in FIG. 2, which corresponds to the back side of the sheet-like material 1 and is upside down from FIG. In FIG. 3, 3v is a right vertical fold line, 4v is a left vertical fold line, 5h is a lower horizontal fold line, 6h is a bag bottom vertical fold line, and 7h is a bag upper vertical fold line. As described above with reference to FIG. 1, the length (that is, the distance) from the upper side T to the bag upper vertical fold line 7h is D1, and the length from the bag upper vertical fold line 7h to the bag bottom vertical fold line 6h (that is, the distance). The distance) is D2, and the length (distance) from the vertical fold line 6h at the bottom of the bag to the lower horizontal fold line 5h is D3.

In the present specification, the terms "up / down" and "left / right" mean the up / down / left / right when the sheet-shaped material 1 is placed in the orientation shown in FIG. 2 for convenience. Further, the side that can be seen when the sheet-shaped material 1 is placed in the orientation shown in FIG. 2 is referred to as the front side, and the side that can be seen when the sheet-shaped material 1 is placed in the orientation shown in FIG. 3 is referred to as the back side.

Next, a step of creating a packaging bag according to the present invention by using the sheet-like material 1 for creating a packaging bag shown in FIGS. 2 and 3 will be described with reference to FIGS. 4 to 19.

FIG. 4 shows a step in which the right end R side end portion of the sheet-shaped material 1 shown in FIG. 2, that is, the right end portion is valley-folded along the auxiliary vertical fold line 2v to form the auxiliary folded portion γ1. .. That is, as shown by the arrow in the figure, the end portion of the sheet-shaped material 1 on the right side R side is valley-folded along the auxiliary vertical fold line 2v to form the auxiliary folded portion γ1. This step corresponds to step (H) in the method for producing a packaging bag according to the present invention. Although this step is not essential and may not be necessary, the step (H) is performed because the end portion on the right side R side of the sheet-like material 1 is reinforced and strengthened by forming the auxiliary folded portion γ1. It is desirable to provide it.

Further, in this example, the end portion on the right side R side of the sheet-like material 1 is valley-folded along the auxiliary vertical fold line 2v to form the auxiliary folded portion γ1, but the right side R side of the sheet-like material 1 is formed. The auxiliary folded portion γ1 may be formed by folding the end portion of the fold along the auxiliary vertical fold line 2v.

FIG. 5 shows a state in which the auxiliary folded portion γ1 is formed on the right side R side of the sheet-like material 1 through the above step (H). The back side of the sheet-like material 1 shown in FIG. 3 appears in the auxiliary folded portion γ1, and the lower horizontal fold line 5h displayed on the back side is continuous with the lower horizontal fold line 5h displayed on the front side. , One lower horizontal fold line 5h is formed. The lower horizontal fold line 5h and the auxiliary vertical fold line 2v are orthogonal to each other.

Next, in FIG. 6, the lower end portion of the sheet-shaped material 1, that is, the end portion on the lower side B side, including the auxiliary folding portion γ1, is valley-folded along the lower horizontal fold line 5h as shown by the arrow in the figure. This shows the process of forming the lower folded portion γ2. This step corresponds to the step (A) in the method for producing a packaging bag according to the present invention. In this example, the lower end portion of the sheet-like material 1 is folded in a valley along the lower horizontal fold line 5h to form the lower folded portion γ2, but the lower end portion of the sheet-like material 1 is folded downward. The lower folded portion γ2 may be formed by folding a mountain along the line 5h.

In FIG. 7, as a result of the lower end of the sheet-shaped material 1 being valley-folded along the lower horizontal fold line 5h including the folded-back portion γ1, the lower folded-back portion γ2 was formed on the lower side of the sheet-shaped material 1. Indicates the state. The back side of the sheet-like material 1 appears in the lower folded portion γ2, and the right vertical fold line 3v and the left vertical fold line 4v displayed on the back side are displayed on the front side, and the right vertical fold line 3v and the left are displayed on the front side. One right vertical fold line 3v and one left vertical fold line 4v are formed in succession to the vertical fold line 4v, respectively. The right vertical fold line 3v and the left vertical fold line 4v are orthogonal to the lower horizontal fold line 5h.

In FIG. 7, Cv-Cv is a center line passing through the center of the sheet-like material 1 in the left-right direction in a state where the lower folded portion γ2 is formed, and the sheet-like material 1 sandwiches the center line Cv-Cv. The distances to the left and right ends (the distance from the center line Cv-Cv to the left side L in FIG. 7 and the distance from the center line Cv-Cv to the auxiliary vertical fold line 2v) are both Wh and are equal. On the other hand, the distance D7, that is, the distance D7 from the auxiliary vertical fold line 2v corresponding to the right end of the sheet-like material 1 in the state where the lower folded portion γ2 is formed to the right vertical fold line 3v is as is clear from FIG. , Who is shorter than Wh and has a relationship of D7 <Wh, and the right vertical fold line 3v is larger than the center line (center line Cv-Cv) in the left-right direction of the sheet-like material 1 in the state where the lower folded portion γ2 is formed. It is located on the right side. Then, as will be described later, the right side portion of the sheet-shaped material 1 is valley-folded or mountain-folded along the right vertical fold line 3v to form the second side folded portion γ4, so that the distance D7 is the second. This corresponds to the length of the side folded portion γ4 in the left-right direction.

On the other hand, the left vertical fold line 4v is located on the left side of the right vertical fold line 3v by the distance D6 from the right vertical fold line 3v to the left vertical fold line 4v. The distance D6 is usually set to be equal to the distance D7 corresponding to the length of the second side folded portion γ4 in the left-right direction, but it does not necessarily have to be set exactly the same, and may be set substantially equal. .. Further, the distance D6 may be set longer than the distance D7. In any case, the length obtained by subtracting the distance D5 (the length from the left vertical fold line 4v to the left side L of the sheet-like material 1) from the distance D6 is shorter than the distance D7, that is, the distance D6-distance D5. The distance D6 is set so that the distance D7. When the position of the left vertical fold line 4v is set so that the distance D6-distance D5 <distance D7, the right part of the sheet-like material 1 is folded in a mountain along the right vertical fold line 3v as described later. Alternatively, the second side folded portion γ4 is formed by valley folding, and the left side portion of the sheet-like material 1 is mountain-folded or valley-folded along the left vertical fold line 4v to form the first side folded portion γ3. At this time, since the tip of the first side folded portion γ3 is located on the right side of the tip of the second side folded portion γ4, the first side folded portion γ3 and the second side folded portion γ4 are engaged with each other. The advantage is that a tubular body can be formed.

Next, in FIG. 8, in a state where the lower folded portion γ2 is formed, the right portion of the sheet-like material 1 includes the auxiliary folded portion γ1 and the lower folded portion γ2, and is vertically folded to the right as shown by the arrow in the figure. The process of valley folding along the line 3v to form the second side folded portion γ4 is shown. This step corresponds to step (B) in the method for producing a packaging bag according to the present invention. As a result of the formation of the second side folded portion γ4, the bag bottom horizontal fold line 6h and the bag top horizontal fold line 7h described on the back side of the sheet-like material 1 appear in the visible portion.

In FIG. 8, α4 is a gap formed inside the lower folded portion γ2 in the tip lower end portion β4 of the second side folded portion γ4. In this example, the auxiliary folded portion γ1 is formed prior to the lower folded portion γ2, and a part of the auxiliary folded portion γ1 is folded back together with the lower folded portion γ2. There is an auxiliary folded portion γ1 that is folded back together with γ2, and this auxiliary folded portion γ1 faces the auxiliary folded portion γ1 that is folded back together with the second side folded portion γ4 to form a gap α4. When the auxiliary folded portion γ1 is not formed, the lower folded portion γ2 directly faces the second side folded portion γ4 and forms a gap α4 inside the lower folded portion γ2. A partially enlarged view of FIG. 8 is shown as FIG.

In this example, the right side portion of the sheet-shaped material 1 is valley-folded along the right vertical fold line 3v to form the second side folded portion γ4. As shown in FIG. 10, the sheet is formed. The right side portion of the shape material 1 may be mountain-folded along the right vertical fold line 3v to form the second side portion folded portion γ4. Also in this case, a gap α4 is formed inside the lower folded portion γ2 at the tip lower end portion β4 of the second side folded portion γ4. Similarly, in this example, the auxiliary folded portion γ1 is formed prior to the lower folded portion γ2, and a part of the auxiliary folded portion γ1 is folded back together with the lower folded portion γ2. There is an auxiliary folded portion γ1 folded back together with the lower folded portion γ2, and this auxiliary folded portion γ1 faces the auxiliary folded portion γ1 folded together with the second side folded portion γ4 to form a gap α4.

Incidentally, from the viewpoint of improving the appearance and handleability of the packaging bag by preventing the auxiliary folded portion γ1 and the lower folded portion γ2 from appearing directly inside or outside the packaging bag, the first is It is preferable that the folding direction of forming the two-side folded portion γ4 is aligned with the folding direction of the auxiliary folded portion γ1 and the lower folded portion γ2. That is, when the auxiliary folded portion γ1 and the lower folded portion γ2 are formed by valley folding, the second side folded portion γ4 folds the right side portion of the sheet-shaped material 1 along the right vertical fold line 3v. On the contrary, when the auxiliary folded portion γ1 and the lower folded portion γ2 are formed by mountain folding, the second side folded portion γ4 is the right side portion of the sheet-like material 1. Is preferably formed by folding a mountain along the right vertical fold line 3v.

On the other hand, from the viewpoint of increasing the engaging force of the portion forming the opening of the packaged packaging bag and increasing the strength of the opening of the packaging bag, the direction of folding back forming the second side folded-back portion γ4 is determined. It is preferable to align with the folding direction of the auxiliary folding portion γ1 and the lower folding portion γ2. That is, when the auxiliary folded portion γ1 and the lower folded portion γ2 are formed by valley folding, the second side folded portion γ4 folds the right side portion of the sheet-shaped material 1 along the right vertical fold line 3v. On the contrary, when the auxiliary folded portion γ1 and the lower folded portion γ2 are formed by mountain folding, the second side folded portion γ4 is the right side portion of the sheet-like material 1. Is preferably formed by valley folding along the right vertical fold line 3v.

When the second side folded portion γ4 is formed in this way, the portion of the sheet-like material 1 corresponding to the distance D6 becomes a portion facing the second side folded portion γ4.

Next, in FIG. 11, in a state where the lower folded portion γ2 shown in FIG. 8 is formed, the left side portion of the sheet-like material 1 including the lower folded portion γ2 is left vertical as shown by an arrow in the figure. It shows a step of valley folding along the folding line 4v to form the first side folded portion γ3. This step corresponds to step (C) in the method for producing a packaging bag according to the present invention.

In FIG. 11, α3 is a gap formed inside the lower folded portion γ2 in the tip lower end portion β3 of the first side folded portion γ3. In this example, since the auxiliary folded portion γ1 is not formed at the left end of the sheet-shaped material 1, the lower folded portion γ2 directly faces the first side folded portion γ3, and the gap α3 is inside the lower folded portion γ2. Is forming. A partially enlarged view of FIG. 11 is shown as FIG.

In this example, the left side portion of the sheet-like material 1 is valley-folded along the left vertical fold line 4v to form the first side folded portion γ3, but the second folded portion γ4 is shown in FIG. When the sheet-like material 1 is formed by mountain fold along the right vertical fold line 3v as shown in FIG. 13, the left side portion of the sheet-like material 1 is mountain-folded along the left vertical fold line 4v. It is preferable to form the first side folded portion γ3 by doing so. Also in this case, as shown in FIG. 13, a gap α3 is formed inside the lower folded portion γ2 in the tip lower end portion β3 of the first side folded portion γ3. In this example, since the auxiliary folded portion γ1 is not formed at the left end of the sheet-shaped material 1, the lower folded portion γ2 folded back together with the first side folded portion γ3 directly faces the first side folded portion γ3. Then, a gap α3 is formed inside the lower folded portion γ2.

Either the first side folded portion γ3 or the second side folded portion γ4 may be formed first.

In FIG. 14, the lower end portion β3 of the tip of the first side folded portion γ3 is inserted between the gaps α4 formed in the lower end portion β4 of the tip of the second folded portion γ4, and the first side folded portion γ3 is inserted. The process of engaging the second side folded portion γ4 with the second side folded portion γ4 is shown. As a result, a tubular body surrounded by the first side folded portion γ3, the second side folded portion γ4, and the sheet-like material 1 of the portion facing the second side folded portion γ4 is formed. In this case, the sheet-like material 1 in the portion facing the second side folded-back portion γ4 is the sheet-like material 1 in the portion sandwiched between the right vertical fold line 3v and the left vertical fold line 4v. .. Inside the tubular body, as shown by the white arrow in FIG. 14, a continuous space is formed from the upper part to the lower part.

Note that FIG. 14 shows a state in which the position of the left vertical fold line 4v is set so that the distance D6 is substantially equal to the distance D7 to form a tubular body, but the position is such that the distance D6> the distance D7. When the left vertical fold line 4v is set and the left side portion of the sheet-like material is mountain-folded or valley-folded along the left vertical fold line 4v to form the first side folded portion γ3, the first side portion is formed. The tubular body formed by engaging the folded portion γ3 and the second side folded portion γ4 includes the first side folded portion γ3, the second side folded portion γ4, and the second side folded portion γ4. A tubular body surrounded by the first side folded portion γ3 and the sheet-shaped material 1 in the portion facing the folded portion γ3 is formed. However, even in this case, the sheet-like material 1 of the portion facing the second side folded portion γ4 and the first side folded portion γ3 is sandwiched between the right vertical fold line 3v and the left vertical fold line 4v. It is the sheet-like material 1 of the removed part.

In FIG. 15, instead of inserting the lower end portion β3 of the tip of the first side folded portion γ3 into the gap α4 of the second folded portion γ4, the lower end portion β4 of the tip of the second side folded portion γ4 is inserted into the first side. The process of inserting into the gap α3 formed in the lower end portion β3 of the tip of the part folding portion γ3, and engaging the first side folding portion γ3 with the second side folding portion γ4 is shown. In this way, instead of inserting the tip lower end β3 of the first side folded portion γ3 into the gap α4 of the second side folded portion γ4, the tip lower end β4 of the second side folded portion γ4 is folded back to the first side. It may be inserted into the gap α3 of the portion γ3, and also by this, the first side portion folded portion γ3, the second side portion folded portion γ4, and the sheet-like material 1 of the portion facing the second side portion folded portion γ4 An enclosed tubular body can be formed. Inside the tubular body, a continuous space is formed from the upper part to the lower part, as shown by the white arrow in FIG.

In the case shown in FIGS. 10 and 13, that is, the second side folded portion γ4 and the first side folded portion γ3 form a right vertical fold line 3v or a right vertical fold line 3v on the right side portion or the left side portion of the sheet-like material 1, respectively. The same applies to the case where the shape is formed by folding a mountain along the left vertical fold line 4v, and the lower end portion β3 of the tip of the first side folded portion γ3 is inserted into the gap α4 of the second side folded portion γ4. Alternatively, the lower end portion β4 of the tip of the second side folded portion γ4 is inserted into the gap α3 formed in the lower end portion β3 of the tip of the first side folded portion γ3, and the first side folded portion γ3 and the first lower end portion γ3 are inserted. By engaging the two side folded portions γ4, it is possible to form a tubular body that internally includes a continuous space from the upper part to the lower part.

As described above, the process described with reference to FIGS. 14 and 15 corresponds to the process (D) in the method for producing the packaging bag according to the present invention.

FIG. 16 is a diagram showing the appearance of the tubular body formed as described above. In FIG. 16, in Ch-Ch, the center of the sheet-like material 1 in the vertical direction in a state where the first side folded portion γ3 and the second side folded portion γ4 are engaged to form a tubular body is formed. It is a center line that passes through, and the distance to the upper and lower ends of the sheet-like material 1 (the distance from the center line Ch-Ch in FIG. 16 to the upper side T and below the center line Ch-Ch) with the center line Ch-Ch in between. The distances up to the horizontal fold line 5h) are all Wv and are equal. On the other hand, the distance D3, that is, the distance D3 from the lower horizontal fold line 5h to the bag bottom horizontal fold line 6h is shorter than Wv and has a relationship of D3 <Wv, as is clear from FIG. Reference numeral 6h is located below the vertical center (center line Ch—Ch) of the sheet-like material 1 in the state where the tubular body is formed. Then, as will be described later, the lower portion of the sheet-like material 1 is valley-folded or mountain-folded along the bag bottom horizontal fold line 6h to form the bag body folded portion γ5, so that the distance D3 is the bag body. It corresponds to the length of the folded portion γ5 in the vertical direction.

On the other hand, the bag top horizontal fold line 7h is located above the bag bottom horizontal fold line 6h by the distance D2 from the bag bottom horizontal fold line 6h to the bag top horizontal fold line 7h. The distance D2 is usually set to be equal to the distance D3 corresponding to the vertical length of the bag body folded-back portion γ5, but it does not necessarily have to be set to be completely equal, and may be substantially equal. Further, the distance D2 may be set longer than the distance D3. In any case, the length obtained by subtracting the distance D1 (the length from the bag upper horizontal folding line 7h to the upper side T of the sheet-like material 1) from the distance D2 is shorter than the distance D3, that is, the distance D2-distance. The distance D2 is set so that D1 <distance D3. When the position of the bag top horizontal fold line 7h is set so that the distance D2-distance D1 <distance D3, the lower portion of the tubular body is formed along the bag bottom horizontal fold line 6h as described later. When the bag body folded portion γ5 is formed by mountain fold or valley fold, and the upper part of the tubular body is mountain-folded or valley-folded along the bag upper horizontal fold line 7h to form the bag upper folded portion γ6, the bag is formed. Since the lower tip of the upper folded portion γ6 is located below the upper tip of the bag body folded portion γ5, the bag upper folded portion γ6 is inserted into the internal space that opens at the upper end of the bag body folded portion γ5, and the bag is inserted. An advantage is obtained that a bag-shaped portion can be formed inside the main body folded portion γ5. That is, the position of the bag upper horizontal folding line 7h is selected so that the lower tip of the bag upper folding portion γ6 is located below the upper tip of the bag body folding portion γ5.

In FIG. 17, in a state where the tubular body is formed, the lower portion of the tubular body is valley-folded along the bag bottom horizontal fold line 6h as shown by an arrow in the figure, and the bag body folded portion γ5 is shown. Is shown in the process of forming. The bag bottom horizontal fold line 6h is parallel to the lower horizontal fold line 5h. This step corresponds to the step (E) in the method for producing a packaging bag according to the present invention.

In FIG. 18, with the bag body folded portion γ5 formed as described above, the upper portion of the tubular body corresponds to the vertical length D3 of the bag body folded portion γ5 from the bag bottom horizontal fold line 6h. The step of forming the bag upper folded portion γ6 by valley folding along the bag upper horizontal folding line 7h located on the upper side by the length to be performed is shown. This step corresponds to step (F) in the method for producing a packaging bag according to the present invention. In FIG. 18, the hatched portion indicated by the reference numeral S is the internal space of the tubular body that opens at the upper end of the bag body folded-back portion γ5.

In the examples shown in FIGS. 17 and 18, the bag body folded-back portion γ5 and the bag top folded-back portion γ6 are both valley-folded along the bag bottom horizontal fold line 6h and the bag top horizontal fold line 7h, respectively. Although it is formed, it may be formed by mountain-folding along the bag bottom horizontal fold line 6h and the bag top horizontal fold line 7h, respectively. However, since it is necessary to insert the bag upper folded portion γ6 into the internal space S that opens at the upper end of the bag body folded portion γ5, it is necessary that both folding directions are the same, and the bag body folded portion γ5 is folded in a valley. When formed, the bag upper folded portion γ6 is also formed by a valley fold, and when the bag body folded portion γ5 is formed by a mountain fold, the bag upper folded portion γ6 is also formed by a mountain fold.

In FIG. 19, the bag upper folded portion γ6 is inserted into the internal space S opened at the upper end of the bag main body folded portion γ5, and the bag-shaped portion 8 is formed inside the bag main body folded portion γ5. The process of forming the packaging bag 9 according to the above is shown. This step corresponds to step (G) in the method for producing a packaging bag according to the present invention.

FIG. 20 shows an example of using the packaging bag 9 according to the present invention. As can be seen in FIG. 20, the packaging bag 9 according to the present invention can be appropriately used for transportation or storage such as when taking out an appropriate product or the like in the bag-shaped portion 8. In addition, when the product is finished in use, it can be easily returned to the original sheet-like material by disassembling it in the reverse order of creation, so it does not become bulky and requires time and effort for storage and disposal as a sheet-like material. Is also extremely small.

Packaging bags are used in every aspect of daily life, but there are concerns about resource depletion and environmental problems with the synthetic resin materials normally used for packaging bags. On the other hand, according to the packaging bag of the present invention, the sheet-like material for creating a packaging bag, and the method for producing the same, it is safe to use a sheet-like material such as paper or cloth that can be easily obtained by anyone. Anyone can easily create a packaging bag with excellent properties and durability, and there is no need to worry about resource depletion and environmental load. The present invention has excellent industrial applicability.

1 Sheet material 2, 3, 4, 5, 6, 7 Fold marks 2v Auxiliary vertical fold line 3v Left vertical fold line 4v Right vertical fold line 5h Bottom horizontal fold line 6h Bag bottom horizontal fold line 7h Bag top horizontal fold line 8 Bag-shaped part 9 Packaging bag T Sheet-like material Upper side B Sheet-like material Lower side R Sheet-like material Right side L Sheet-like material Left side α3, α4 Gap β3, β4 Tip lower end γ1 Auxiliary fold γ2 Lower fold γ3 First side Folded part γ4 2nd side folded part γ5 Bag body folded part γ6 Bag upper folded part

Claims (6)

A packaging bag made by folding a sheet-like material.
A lower folded portion γ2 formed by valley-folding or mountain-folding the lower end portion of the sheet-shaped material along a straight lower horizontal fold line, and a lower folded portion γ2.
With the lower folded portion γ2 formed, the right portion of the sheet-shaped material is located on the right side of the center in the left-right direction of the sheet-shaped material and along the right vertical fold line orthogonal to the lower horizontal fold line. 2nd side folded part γ4 formed by valley folding or mountain folding, and
With the lower folded portion γ2 formed, the lower folded portion γ2 is located on the left side from the right vertical fold line by a length substantially equal to or longer than the lateral length of the second side folded portion γ4, and the lower horizontal fold is formed. Along the left vertical fold line orthogonal to the line, the left side portion of the sheet-like material is formed by valley fold or mountain fold on the same side as the second side folded portion γ4, and the tip thereof is formed by the second side. A first side folded portion γ3 located on the right side of the tip of the folded portion γ4 is provided.
The second side folded portion γ4 and the first side folded portion γ3 are such that the lower end portion of the tip of the first side folded portion γ3 is located at the lower end portion of the tip of the second side folded portion γ4. The lower end of the tip of the second side folded portion γ4 is located at the lower end of the tip of the first side folded portion γ3, or is inserted into the gap formed inside the lower folded portion γ2. By being inserted into the gap formed inside the lower folded portion γ2, they engage with each other, and the first side folded portion γ3, the second side folded portion γ4, the right vertical folding line and the said A tubular body surrounded by the sheet-like material in the portion sandwiched between the left vertical fold line is formed.
Further, in the state where the tubular body is formed, the lower portion of the tubular body is located below the center in the vertical direction of the tubular body, and the bottom of the bag is laterally folded parallel to the lower horizontal fold line. The folded portion γ5 of the bag body formed by folding valleys or mountains along the line, and
With the bag body folded portion γ5 formed, the upper part of the tubular body is upward by a length substantially equal to or longer than the vertical length of the bag body folded portion γ5 from the bag bottom horizontal fold line. It is formed by a valley fold or a mountain fold on the same side as the bag body folding portion γ5 along the bag upper horizontal folding line parallel to the lower horizontal folding line, and the lower tip thereof is formed by folding the bag body. A bag upper folded portion γ6 located below the upper tip of the portion γ5 is provided.
The bag-shaped portion formed inside the bag body folded portion γ5 by inserting the tip end portion of the bag upper folded portion γ6 into the tubular body of the bag body folded portion γ5 is provided.
Packaging bag. It has an auxiliary folding portion γ1 formed by folding the right end portion or the left end portion of the sheet-shaped material in a valley fold or a mountain fold along an auxiliary vertical fold line orthogonal to the lower horizontal fold line.
The lower folded portion γ2 is formed by valley-folding or mountain-folding the lower end portion of the sheet-like material along the lower horizontal fold line in a state where the auxiliary folded portion γ1 is formed. The packaging bag according to claim 1, which is γ2. The lower horizontal fold line, the right vertical fold line, the left vertical fold line, the bag bottom horizontal fold line, and the bag upper horizontal fold line are described in claim 1 at predetermined positions inside the rectangle. Sheet-like material for making the described packaging bag. In addition to the lower horizontal fold line, the right vertical fold line, the left vertical fold line, the bag bottom horizontal fold line, and the bag upper horizontal fold line, the auxiliary vertical fold line is placed at a predetermined position inside the quadrangle. The sheet-like material for making a packaging bag according to claim 2. A method of folding a sheet-like material to make a packaging bag, which comprises the following steps (A) to (G);
(A) A step of forming a lower folded portion γ2 by making a valley fold or a mountain fold along a straight lower horizontal fold line at the lower end portion of the sheet-shaped material.
(B) The sheet-like material is located on the right side of the center of the sheet-like material in the left-right direction with the lower folded portion γ2 formed, and is located along the right vertical fold line orthogonal to the lower horizontal fold line. A step of forming a second side folded portion γ4 by folding a valley or a mountain on the right side of the
(C) In a state where the lower folded portion γ2 is formed, the lower folded portion γ2 is located on the left side from the right vertical folding line by a length substantially equal to or longer than the lateral length of the second side folded portion γ4. Along the left vertical fold line orthogonal to the lower horizontal fold line, the left side portion of the sheet-like material is valley-folded or mountain-folded to the same side as the second side fold-back portion γ4 to form a first side fold-back portion γ3. The position of the left vertical fold line is selected so that the tip of the first side fold-back portion γ3 to be formed is located on the right side of the tip of the second side fold-back portion γ4. Process,
(D) The lower end of the tip of the first side folded portion γ3 is inserted into the gap formed inside the lower folded portion γ2 located at the lower end of the tip of the second side folded portion γ4. Alternatively, the lower end portion of the tip of the second side folded portion γ4 is inserted into a gap formed inside the lower folded portion γ2 located at the lower end portion of the tip of the first side folded portion γ3. The second side folded portion γ4 and the first side folded portion γ3 are engaged with each other, and the first side folded portion γ3, the second side folded portion γ4, the right vertical folding line and the said A step of forming a tubular body surrounded by the sheet-like material in a portion sandwiched between the left vertical fold line and the left vertical fold line.
(E) With the tubular body formed, the lower portion of the tubular body is located below the center of the tubular body in the vertical direction, and the side of the bottom of the bag parallel to the lower horizontal fold line. A step of forming a folded portion γ5 of a bag body by folding a valley or a mountain along a folding line.
(F) With the bag body folded portion γ5 formed, the length of the upper portion of the tubular body is substantially equal to or longer than the vertical length of the bag body folded portion γ5 from the bag bottom horizontal fold line. The bag upper folded portion γ6 is formed by making a valley fold or a mountain fold on the same side as the bag main body folded portion γ5 along the bag upper horizontal fold line which is located on the upper side and is parallel to the lower horizontal fold line. In the step, the position of the bag upper horizontal fold line is selected so that the lower tip of the bag upper folded portion γ6 to be formed is located below the upper tip of the bag body folded portion γ5. Process,
(G) A step of forming a bag-shaped portion inside the bag body folded portion γ5 by inserting the tip end portion of the bag upper folded portion γ6 into the tubular body of the bag body folded portion γ5. Moreover,
(H) A step of forming an auxiliary folded portion γ1 by folding a right end portion or a left end portion of the sheet-shaped material along a valley fold or a mountain fold along an auxiliary vertical fold line orthogonal to the lower horizontal fold line.
Including
In the step (A), the lower folded portion γ2 is formed by folding the lower end portion of the sheet-shaped material in a valley fold or a mountain fold along the lower horizontal fold line in a state where the auxiliary folded portion γ1 is formed. The process of forming,
The method for producing a packaging bag according to claim 5.

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