JP7191637B2 - paper bag - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper bag in which one end of a rectangular tubular bag body having a front wall, a rear wall and both side walls is sealed as a bottom and the other end is sealed after being filled with contents.

Conventionally, a paper bag is used as an outer packaging (stacked packaging) for collectively packaging a plurality of small bags filled with commodities such as granular materials in a plastic bag or the like (see Patent Document 1).
Here, pressure-sensitive adhesive is mainly used as the adhesive that serves as the sealing means, and as shown in FIG. Due to the large amount of pressure-sensitive adhesive, a large amount of pressure-sensitive adhesive is used, and when sealing, it adheres to unexpected parts, which tends to cause sealing defects such as misalignment of the bonding position and wrinkles. There is a problem that the paper bags adhere to each other, which is likely to cause blocking.
In addition, as a means or method for sealing a paper bag such as an envelope, the adhesive is not applied from the upper part of the front wall to the entire rear wall, and the front wall and the rear wall are provided with a large number of small squares, small circles, or the like. means and method for sealing using an adhesive (see Patent Document 2 and Patent Document 3), and means and method for sealing by bonding the front wall and the rear wall with an adhesive in the longitudinal direction of the envelope However, (see Patent Document 4), these are intended to achieve both sealing performance and ease of opening, and do not suggest or describe solving the above problems.

Japanese Utility Model Publication No. 52-022491 Japanese Utility Model Laid-Open No. 3-029441 JP 2017-202861 A JP 2004-352304 A

In order to solve the above problems, the present invention applies a pressure-sensitive adhesive only to the tip portion of the flap portion of the rear wall, and applies the pressure-sensitive adhesive to at least the upper portion of the flap portion of the front wall. and preferably by applying the pressure-sensitive adhesive only to the portion of the front wall where the tip portion of the flap portion of the rear wall abuts, thereby reducing the amount of pressure-sensitive adhesive used and the sealing failure during sealing. To provide a paper bag which reduces the incidence of blocking and the incidence of blocking during storage of the paper bag, thereby reducing the production cost of the paper bag and improving convenience during use and storage.

The present invention is a paper bag in which one end of a square tube-shaped bag body having a front wall, a rear wall and both side walls is sealed as a lower bottom, and the other end is sealed after being filled with contents. , the front wall, the rear wall, and both side walls are formed with flap portions extending independently from each other, wherein the length of extension of the flap portion of the rear wall is equal to the length of the front wall; A pressure sensitive adhesive is applied to the inner surface of the portion of the rear wall flap portion that extends beyond the front wall and the side wall flap portions for a length greater than the extension length of the wall and the side wall flap portions. However, no pressure-sensitive adhesive is applied to the portion from the proximal end of the flap portion of the rear wall to the extended length of the flap portions of the front wall and the side wall; To provide a paper bag characterized in that no pressure-sensitive adhesive is applied to at least the upper part of the flap part of the wall.
Here, the extending lengths of the flap portions of the front wall and the side walls may be the same, or one of them may be longer.
In addition, the upper portion of the front wall flap means a portion of the front wall flap that abuts on a portion of the rear wall flap that is not coated with the pressure-sensitive adhesive, and is preferably 1 cm or more. and more preferably 3 cm or more. Heights less than 1 cm do little to reduce pressure sensitive adhesive usage.
Further, the fact that at least the upper portion of the flap portion of the front wall is not coated with pressure sensitive adhesive is not only that the upper portion of the flap portion of the front wall is not coated with pressure sensitive adhesive, but also that the top portion of the flap portion of the front wall is not coated with pressure sensitive adhesive. The flap portion of the front wall is entirely free of pressure sensitive adhesive, and the front wall is entirely free of pressure sensitive adhesive. That is, the sealing of the other end is accomplished solely by a pressure sensitive adhesive applied to the flap portion of the rear wall.

In the embodiment of the paper bag, when sealing the other end, as long as the flap portion of the rear wall is folded last, either the flap portion of the front wall or the flap portions of the both end walls may be folded first. Since it is difficult to create a gap at the other end after sealing, and the possibility of dust, foreign matter, etc. entering the paper bag can be reduced, the front wall flap is folded first, and then the both end wall flaps are folded. After that, the paper bag is sealed by folding the flap portion of the rear wall, and the portion of the outer surface of the front wall that contacts the inner surface of the flap portion of the rear wall to which the pressure-sensitive adhesive is applied is felt. It is preferably coated with a pressure adhesive.
Further, the outer surface of the front wall means the outer surface with respect to the inner inner surface, and can also be referred to as the front surface or surface of the front wall.

In the embodiment of the paper bag, when sealing the other end, the front wall flap portion is first folded, then the both end wall flap portions are folded, and then the rear wall flap portion is folded and sealed. wherein the pressure-sensitive adhesive is applied to the outer surface of the front wall and the lower portion of the flap portion of the front wall where the pressure-sensitive adhesive-coated inner surface of the flap portion of the rear wall abuts. It is preferably coated.
Here, the lower portion of the flap portion of the front wall means the lower portion of the flap portion that is connected to the outer surface of the front wall, and is convenient for distinguishing from the upper portion of the flap portion. It is a representation, and the positions of the upper and lower boundaries are not strictly defined.

In the embodiment of the paper bag, the one end sealed as the lower bottom of the square tube-shaped bag main body is provided with an unsealing tape or an unsealing string along the longitudinal direction on the front wall that is folded last. It is preferable that the sealing is performed by affixing the reinforced paper.

In the embodiment of the paper bag, the extension length of the flap portions of the side walls is smaller than the extension length of the flap portions of the rear wall, but is greater than the extension length of the flap portions of the front wall. When pressure adhesive is applied, the flap portions of the side walls are folded into a V-shape to flatten the bag body and in such a state the sides extending beyond the flap portions of the front wall. A pressure sensitive adhesive is preferably applied to the inner surface of the wall and the flap portion of the rear wall.

In the embodiment of the paper bag, examples of the method of applying the pressure-sensitive adhesive include a method using a spray, a method using a glue gun, and a method using a rotary press, but the method of application is limited to these. not to be
Here, it is preferable to use a coating method using a rotary press because it is possible to prevent the pressure-sensitive adhesive from scattering in the air, and it is inexpensive and efficient.

The present invention relates to a paper bag used as an outer packaging (integrated packaging) for collectively packaging a plurality of small bags filled with commodities such as granular materials in a plastic bag or the like, which has a front wall, a rear wall and both side walls. This is a paper bag in which one end of a rectangular tube-shaped bag body is sealed as a lower bottom, and the other end is sealed after being filled with contents.
In the paper bag, the flap portions of the front wall, the rear wall, and the side walls formed at the other end are provided with cuts (also referred to as slits) at four corners of the other end. form the front, rear and side wall flaps.
That is, the flap portion of the front wall is formed by two notches provided at the corners of the front wall and the right and left walls.
Similarly, the rear wall flap is formed by two notches at the corners of the rear wall and the right and left walls.
Furthermore, the right and left wall flaps have two notches at the corners of the right and front and rear walls respectively, and two notches at the corners of the left and front and rear walls. formed by
Here, the incisions can be made by means and methods that are usually used by those skilled in the art, such as cutters, and are not particularly limited.

In addition, regarding the length of the cut, when the other end is sealed after being filled with contents, the flap portions of the front wall and both side walls are folded in, and finally the flap portion of the rear wall is folded. If the folding positions of the flap portions of the front wall, the rear wall and the side walls are different in height, the four flap portions cannot be neatly folded. If this is the case, the packing condition after sealing will deteriorate, and there will be a gap in the folded part, which will increase the possibility of dust, foreign matter, etc. entering the inside of the paper bag. The height must be set so that the height of the folding position of the flap part is the same.

The extension length of the flap portions of the front wall, rear wall and both side walls is the same as the notch of each flap portion described above when the left and right ends of the tip portion of the flap portion described below are not chamfered. Same as length. When chamfering is performed, the chamfered length becomes longer than the cut length of each flap portion.
The length of extension of the rear wall must be greater than the length of extension of the front and side wall flaps. This is because when the other end is sealed, the flap portion of the rear wall is folded in last, so the portion to which the pressure-sensitive adhesive is applied is necessary.
Further, the extending length of the flap portions of the front wall and both side walls may be the same, or one of them may be longer. However, if the extended length of the flap portion of the front wall is greater than the extended length of the flap portions of the both side walls, when the flap portion of the front wall is folded, the tip of the flap portion will hit the rear wall in a state of surplus. Therefore, it is necessary to fold the flap further, creating a gap in the folded portion, which increases the possibility of dust, foreign matter, etc. entering the paper bag. It is preferable that the extending length of the portion is greater than the extending length of the flap portion of the front wall.
The extension lengths of the flap portions on both side walls may be different, but are preferably the same. This is because when the paper bag of the present invention is cut out from a single sheet of paper as a raw material, by so-called staircase cutting, which is usually used by those skilled in the art, in the case of cutting out the same continuous shape, the extension length of the flap part on both side walls is the same. This is because there is no need for post-processing and wasteful paper is not generated.

The left and right ends of the tip portions of the flap portions of the front wall, rear wall and both side walls may be chamfered as necessary. The portion and shape of the chamfer are arbitrary. It is preferable because it improves the prevention of so-called burping, that is, curling up from the part.

1 is a plan view of a flattened paper bag of the present invention prior to application of a pressure sensitive adhesive; FIG. 2 is a perspective view of the paper bag of FIG. 1; FIG. FIG. 2 is a perspective view of the paper bag of FIG. 1 with both side walls unfolded; FIG. 4 is a plan view of the paper bag of the present invention in a flattened state after applying a pressure sensitive adhesive; FIG. 5 is a perspective view of the paper bag of FIG. 4 with both side walls unfolded; 6 is a perspective view of the paper bag of FIG. 5 with the front wall folded. FIG. FIG. 6 is a perspective view of the paper bag of FIG. 5 after all flaps are folded and sealed. FIG. 6 is a side view of the paper bag of FIG. 5 after all flaps are folded and sealed. 1 is a plan view of a flattened prior art paper bag after pressure sensitive adhesive has been applied all the way from the top of the front face to the back wall; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of a paper bag according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to this embodiment.

The paper bag according to the present invention is usually cut out from a single sheet of paper in the same continuous shape by so-called staircase cutting, which is usually used by those skilled in the art. A rectangular tube-shaped bag body having a wall 1, side walls 2 and a front wall 3 is manufactured. Here, in the staircase cutting step, four corners at the other end of the rectangular tube-shaped bag body are cut to form the flap portions of the respective walls.

FIG. 1 shows a plan view of a flattened paper bag of the present invention prior to application of a pressure sensitive adhesive.
2 is a perspective view of the paper bag of FIG. 1 showing the notches and the flaps 4 to 6 of each wall, and FIG. 3 is a perspective view of the paper bag of FIG. Figure shows. Here, the dotted lines indicate the fold lines of the flap portion on each wall and the fold lines of the V-shaped configuration on both side walls.
Further, the flap portion 4 extends from the rear wall 1, the flap portion 5 extends from the both side walls 2, and the flap portion 6 extends from the front wall 3 independently, respectively. The size relationship between the width 8 and the extension length 9 of the flap portion 6 is "extension length 7>extension length 8>extension length 9", and the extension length of the flap portion of the rear wall. The length 7 is greater than the extended length 8-9 of the flap portions of the front wall and the side walls.
The length 10 of the two cuts provided at the corners of the rear wall, the right side wall and the left side wall, and the length 11 of the two cuts provided at the corners of the front wall and the right side wall and the left side wall. Although the relationship is different as "length of cut 10>length of cut 11", the height of the tip of the cut is the same, and the height of the folding position of all the flaps is the same. .

FIG. 4 shows a plan view of the paper bag of the present invention shown in FIG. 1 after applying a pressure-sensitive adhesive using a rotary press.
Here, there is an adhesive application area 12 coated with a pressure-sensitive adhesive on the inner surface of the portion of the flap portion of the rear wall that extends beyond the flap portions of the front wall and both side walls. Dotted lines in (1) indicate folding lines that abut against the folding lines of the front wall.
The upper and lower parts of the adhesive application area 12 contact the adhesive application area 14 on the outer surface of the front wall and the adhesive application area 15 below the flap portion of the front wall, respectively.
Also, the upper portion 13 of the flap portion of the front wall is not coated with a pressure sensitive adhesive.

FIG. 5 shows a perspective view of the paper bag of the present invention filled with contents and unfolding both side walls 2 folded into a V shape, and FIG. 6 shows the front wall of the paper bag shown in FIG. The perspective view of the state where only the flap part 6 was folded is shown.
Here, a pressure-sensitive adhesive is applied to the portion (concave portion) from the base end portion of the flap portion 4 of the rear wall to the extension length of the flap portions 5 and 6 of the front wall and both side walls. is not coated.

After that, the flap portions 5 of both side walls are folded in, and finally the flap portion 4 of the rear wall is folded in, so that the adhesive application area 12 of the rear wall contacts and is sealed with the adhesive application areas 14 to 15 of the front wall. .
7 and 8 show a perspective view and a side view of the sealed paper bag shown in FIG.

FIG. 9 shows a prior art paper bag after the pressure sensitive adhesive has been applied all the way from the top of the front wall to the back wall, where the large area of the pressure sensitive adhesive application area 16 results in a pressure sensitive adhesive. A large amount of adhesive is used, which increases the manufacturing cost of the paper bag. When sealing the bag, it adheres to an unexpected part, and sealing defects such as misalignment of the bonding position and wrinkles are likely to occur. There is a problem that the convenience during use and storage is not preferable because blocking is likely to occur when the paper bags are adhered to each other.

1: Rear wall 2: Both side walls 3: Front wall 4: Rear wall flap 5: Both side wall flaps 6: Front wall flap 7: Extension length of rear wall flap 8: Both side walls Extension length of the flap part 9: Extension length of the flap part of the front wall 10: Length of the two notches provided at the corners of the rear wall and the right and left walls 11: The front wall and the right and left walls 12: Adhesive application area on the inner surface of the rear wall flap 13: Top of the front wall flap where no adhesive is applied 14: On the outer surface of the front wall Glue application area 15: Glue application area under the flap portion of the front wall 16: Overall adhesive application area from the top of the front wall to the back wall

Claims (3)

A paper bag in which one end of a rectangular tubular bag body having a front wall, a rear wall and both side walls is sealed as a lower bottom, and the other end is sealed after being filled with contents, wherein the front wall is located at the other end , the paper bag in which the rear wall and the both side walls are formed with flap portions extending independently,
the flap portion of the rear wall extends in length greater than the flap portions of the front wall and both side walls;
A pressure sensitive adhesive is applied to the inner surface of the portion of the rear wall flap portion that extends beyond the front and side wall flap portions,
A pressure-sensitive adhesive is not applied to a portion from the proximal end of the flap portion of the rear wall to the extension length of the flap portions of the front wall and both side walls,
Further, at least an upper portion of the flap portion of the front wall is not coated with a pressure sensitive adhesive,
A paper bag, wherein a pressure-sensitive adhesive is applied to a portion of the outer surface of the front wall that contacts the pressure-sensitive adhesive-applied inner surface of the flap portion of the rear wall . 2. A pressure-sensitive adhesive is applied to a portion of the lower portion of the flap portion of the front wall where the pressure-sensitive adhesive-applied inner surface of the flap portion of the rear wall abuts. Paper bag with description. The one end sealed as the lower bottom of the rectangular tubular bag body is pasted with an opening tape or an opening string on the front wall that is folded last, and a reinforcing paper provided along the longitudinal direction. 3. The paper bag according to claim 1, wherein the paper bag is sealed by being worn.

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