JPH0761452A - Bag with rectangular bottom - Google Patents

Abstract

PURPOSE:To enhance moisture-proof property and strength of a bag by gusseting both sides with a laminated sheet with a synthetic resin laminated as outer faces and providing a hole or a cut on an approximately triangular inner flap on a doubled part of a trapezoidal fold flap with a bottom connected to opposite sides. CONSTITUTION:A gusset-cylindrical bag material is made of a paper sheet having a surface 21 with a synthetic resin laminated on an outer face. A portion which is to be a bottom when this bag material is completed is opened and pushed flat to make a semi-completed bottom exhibiting an approximate octagon at the bottom of the bag material. At this time a hole 11 is drilled on an approximately triangular inner flap at doubled parts of trapezoidal fold flaps 8,8' of the semi-completed bottom in advance. After adhesive agent is applied on the inner flap including the hole 11 on the trapezoidal fold flap 8, the inner flap is folded and adhered to make a complete rectangular bottom 15, thereby obtaining a strong bag 1 with a rectangular bottom wherein the adhesive has been penetrated to a surface where the synthetic resin is not laminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a square bottom bag which is made of paper having a synthetic resin layer on one side and is used for mail delivery, home delivery and the like.

[0002]

2. Description of the Related Art Conventionally, a square-bottomed bag used for delivery by mail or home delivery has the functions of preventing water absorption due to rain, preventing moisture of contents, holding heavy contents, and reinforcing the strength of the bag. A sheet of paper having a synthetic resin layer on its outer surface is used. In the case of those corner bottom bags, there is a portion where the synthetic resin layer surfaces must correspond to each other in the corner bottom portion of the bag manufactured by bottom folding, and it is difficult to bond the synthetic resin layer surfaces to each other. In addition, the adhesive strength at the bottom may be insufficient.

For this reason, when a sheet without a synthetic resin layer is used on the entire corner bottom portion to be folded at the bottom, prevention of water absorption due to rain, moisture prevention of contents, retention of heavy contents, bag strength. There was a drawback that the function of reinforcement was partially lost.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet having a synthetic resin layer on the surface of the bottom of the square bottom bag. To prevent water absorption due to rain, etc.
An object of the present invention is to provide a square bottom bag which is excellent in holding high-weight contents and reinforcing the strength of the bag.

[0005]

In order to achieve the above object, the square bottom bag of the present invention is a laminated sheet in which a synthetic resin layer is laminated on one surface of a paper base material with the synthetic resin layer surface as the outer surface. In a square bottom bag that is gusseted on both sides in the state, and the bottom surface is connected to opposite sides by a trapezoidal folding flap and formed into a rectangular shape, the trapezoidal folding flap has a double-sided inner surface that is substantially triangular. The flap is provided with a perforated portion or a notched portion.

Further, in the above-mentioned square bottom bag, the inner surface flap is provided with a portion where at least one surface of the portion which is abutted when folded is not laminated with the synthetic resin layer.

[0007]

In the present invention, the perforated portion or the cutout portion is provided on the inner surface flap side having a substantially triangular shape in the double portion of the trapezoidal folding flap at the portion where the synthetic resin layer surfaces are correspondingly bonded to each other at the corner bottom portion, Further, the inner surface flap has a structure in which a synthetic resin layer is not laminated on a part of at least one surface of the portion that comes into contact with the inner flap when the synthetic resin layer is laminated. It becomes possible to permeate into the uncovered surface, and the adhesive strength of the corner bottom portion in bottom folding can be enhanced.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an overall perspective view showing a square bottom bag of the present invention, and FIG. 2 is a perspective view showing in sequence the method of assembling the square bottom bag of the present invention.

A method of assembling the square bottom bag 1 of the present invention will be described with reference to FIG. 2. A surface 21 on which an outer surface of synthetic resin such as polypropylene is laminated by a suitable laminating means such as extrusion lamination or dry lamination is used. Paper 2
The adhesive 4 is applied to the outer surface (the surface 21 on which the synthetic resin is laminated) of the right side edge portion 3'of (a).

Next, by folding the sheet 2 at a position slightly left of the center line parallel to the feeding direction and at a position slightly inward of the right side edge 3'of the sheet 2 into an M-shape, Fold folds 5 and 5 ′ are formed, and the left and right edges 3 and 3 ′ of the paper 2 are polymerized and adhered with the adhesive 4 to form a gusset tubular bag material 6. (b).

Next, the bag material 6 is opened at a portion which will be the bottom after completion of the bag material 6, and the opened bottom is crushed into a flat shape so that the bottom of the bag material 6 has a substantially octagonal shape. The finished bottom 7 is formed. At this time, a perforation portion 11 is previously formed in the substantially triangular inner surface flap portions 9, 9 ', 10, 10' by a double portion of the trapezoidal folding flap on the semi-finished bottom 7 and the semi-finished bottom 7 is also formed. Nijo's broken line 12, 1
Trapezoidal flap 8 on semi-finished bottom 7 by 2 ',
To form 8 '(c).

Next, one trapezoidal folding flap 8
After applying the adhesive to the inner surface flap portions 9 and 9 ′ including the perforated portion 11 in FIG. Then, the trapezoidal folding flap 8'when the inner surface flap portion 10 and 10 'including the perforated portion 11 of the other trapezoidal folding flap 8'and the portion 13 of the trapezoidal folding flap 8'which is not a double portion are folded. After the adhesive is applied to the overlapping portion 13 ', it is folded and adhered by the polygonal line 12' to obtain a square finished bottom 15.
(e) As a result, the square bottom bag 1 as shown in FIG. 1 is obtained.

In FIG. 2- (c), the middle flap 1 of the trapezoidal folding flap 8 and the middle flap 1 of the semi-finished bottom 7 are shown.
4, the inner surface flap portion 9'corresponds to the middle portion 14 'of the semi-finished bottom 7, and an adhesive is applied and attached. Therefore, by forming the perforated portion 11 in the inner surface flap portions 9 and 9 ′, the adhesive applied to the inner surface flap portions 9 and 9 ′ is exposed through the perforated portion 11 into the perforated portion 11. The synthetic resin of the shape folding flap 8 penetrates into the surface 22 where the synthetic resin is not laminated, and the surface 22 where the synthetic resin is not laminated and the semi-finished bottom 7
The inner flaps 9 and the middle flaps 14 of the semi-finished bottom 7 and the inner flaps 9'because the middle flaps 14 and 14 'are attached.
Then, the middle portion 14 'of the semi-finished bottom 7 is securely attached.

Further, in FIG. 2 (d), the inner flap portion 10, the middle portion 14 of the semi-finished bottom 7 and the inner flap portion 1 are shown.
0 ′, the middle portion 14 ′ of the semi-finished bottom 7 and the trapezoidal folding flap 8 ′ surface 22 on which the synthetic resin is not laminated and the trapezoidal folding flap 8 outer surface on which the synthetic resin is laminated 2
1 corresponds to each other, and an adhesive is applied and attached. Therefore,
By forming the perforated portion 11 in the inner surface flap portions 10 and 10 ′, the adhesive applied to the inner surface flap portions 10 and 10 ′ is trapezoidal fold exposed through the perforated portion 11 into the perforated portion 11. The surface 2 of the flap 8 ′ which has penetrated the synthetic resin non-laminated surface 22 and is not laminated with the synthetic resin 2
2 and the middle portion 14, 14 'of the semi-finished bottom 7 and the trapezoidal folding flap 8', the portion 13 'and the trapezoidal folding flap that overlap with the trapezoidal folding flap 8 when the non-double portion 13 is folded. The inner surface flap portion 10, the middle portion 14 of the semi-finished bottom 7 and the inner surface flap portion 1 are adhered to each other by adhering the synthetic resin laminated surface 21 of the outer surface 8.
0 ′ and the middle part 14 ′ of the semi-finished bottom 7, and the surface 22 of the trapezoidal folding flap 8 ′ on which the synthetic resin is not laminated and the outer surface 21 of the trapezoidal folding flap 8 on which the synthetic resin is laminated are reliable. Will be attached to.

The inner flap portion 9 of the semi-finished bottom 7,
The perforated portion 11 provided in 9 ', 10, 10' is provided to allow the adhesive or pressure-sensitive adhesive applied to the inner surface flap portion 9, 9 ', 10, 10' to penetrate into the surface 22 on which the synthetic resin is not laminated. It is provided, the size is appropriate,
It suffices if the inner surface flap portions 9, 9 ', 10, 10' are within the respective areas, and the shape thereof is shown by forming the perforation portion 11 in a triangular shape in the embodiment, but the shape of the perforation portion 11 is not shown. The shape is not limited to one, and may be a quadrangle, another polygon, or a circle. Also, the inner flap portion 9,
You may provide a notch in the inner edge of 9 ', 10, 10',
The inner flap portions 9, 9 ', 10, 10' may be cut off.

Further, the inner flap portions 9, 9 ', 10, 1
0'abuts at the time of folding, and at least one surface of the portion to be adhered by folding with the adhesive is made a portion where the synthetic resin layer is not laminated, so that the applied adhesive penetrates into the paper surface. It will be surely attached.

[0017]

As described above, according to the present invention, a sheet in which a synthetic resin layer is laminated on the entire surface of the outer side of the paper bag is used. A perforated portion is provided on one side of the sheet, and the adhesive is permeated through the perforated portion to the surface on which the synthetic resin is not laminated, so that the adhesive can be adhered. It is relatively easy to obtain a square-bottomed bag capable of holding objects and sufficiently reinforcing the strength of the bag.

[Brief description of drawings]

FIG. 1 is a perspective view of a square bottom bag of the present invention.

FIG. 2 is a perspective view showing in sequence the method of assembling the square bottom bag of the present invention.

[Explanation of symbols]

 1 square bottom bag 2 paper 21 surface laminated with synthetic resin. 22 Surface not laminated with synthetic resin 3 Left edge 3'Right edge 4 Adhesive 5, 5'Folded folds 6 Bag material 7 Semi-finished bottom 8 8 'Trapezoidal folded flaps 9 9'10 10' Inner surface Flap part 11 Perforated part 12 12 'Folded line 13 Part that does not become double part of folding flap 13' Part that overlaps with folding flap when folding 14 14 'Middle part of semi-finished bottom 15 Square finished bottom

Claims (2)

[Claims] 1. A trapezoidal fold in which a laminated sheet in which a synthetic resin layer is laminated on one surface of a paper base material is gusset-folded on both sides with the synthetic resin layer surface being the outer surface, and the bottom surfaces are connected to opposite sides. A rectangular bottom bag formed by sticking and forming a rectangular shape with a flap, characterized in that a perforated portion or a cutout portion is provided on an inner flap having a substantially triangular shape with the double portion of the trapezoidal folding flap. 2. The corner bottom bag according to claim 1, wherein the inner surface flap is provided with a portion where at least one surface of the portion which is abutted when folded is not laminated with the synthetic resin layer.