JPH11227792A - Multilayer bag with unfoldable hexagonal bottom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a satisfactory bottom unfolding characteristic, by partially bonding a plastic tube to a bag wall, which is on the side where a bottom is folded and at the closed end of a bag body having an inner bag in which the bottom of the plastic tube as an innermost layer is heat-sealed. SOLUTION: A tubular body 1 comprises a plastic tube 2 as an innermost layer, and paper layers 3 superimposed on the outside of it, and the tube 2 and paper layers 3 are partially bonded in the form of dots by means of a layers-bonding parts 4 and 5 having a cutting line between them. The layers- bonding parts 4 and 5 are set as open end and closed end, respectively, which are made when the tubular body 1 is cut along the cutting line. A bag material is formed into the pleatless tubular body 1 by being folded along the side crease- line of the tubular body 1 and by being fastened with body glue. The tube 2 is partially bonded to the paper layer 3 on a rear wall by means of the layers- bonding part 5 at the closed end, and folded together with the rear wall 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hexagon-bottomed multi-layer bag, and more particularly, to filling a content, the folded bottom can be quickly and without any trouble by the content put into the bag from a weighing machine. The present invention relates to a hexagon-bottom opening multilayer bag that is improved to be spread.

[0002]

2. Description of the Related Art A layer in which a plastic tube having no folds constituting an innermost layer of a bag body can be stacked on the outside thereof,
The end of the innermost plastic tube is heated and pressed at one end to one wall side and at the other end to the one end of the cylindrical body partially adhered to both wall sides. Is closed by heat sealing, and further, the end portion is opened around a first fold line parallel to the edge thereof to form an open portion having triangular fold portions at both corners, and the first fold line is formed. A second fold line parallel to the fold line is provided at a symmetrical position on both sides of the fold line, an outer portion thereof is bent inward along these second fold lines, overlapped and adhered to form a bottom portion, and the other is opened. Hexagon-bottom opening multilayer bags with ends have been known for a long time, and have been widely used as packaging materials for chemical products.

A multilayer bag having this structure is disclosed in, for example,
No. 25677 (hereinafter referred to as the former) and U.S. Pat. No. 3,540,356 (hereinafter referred to as the latter). As shown in FIG. 9, in the former, the innermost plastic tube (2) is U-shaped along the first fold line (7b) of the bag wall (1b) on the side where the bottom is folded, and 2 shows an example in which the bag wall (1b) is bent in an inverted U-shape along a second folding line (8b) of the same bag wall (1b). (Hereinafter, it is referred to as “A type”.) On the other hand, as shown in FIG.
An example is shown in which the plastic tube (2) extends straight to the second fold line (8a) of the bag wall (1a) on the side opposite to the A type, and is bent in a U-shape there. , "B type").

[0004]

However, in this type of hexagon-bottomed multilayer bag, when the contents are filled, the folded bottom is quickly spread by the contents put into the bag from the weighing machine. Some complained that the contents would overflow from the opening of the bag. The present invention has been made in view of such circumstances, the problem is that the bottom is good,
It is an object of the present invention to provide a hexagon-bottom opening multilayer bag having an inner bag in which the bottom of a plastic tube is heat-sealed as the innermost layer.

[0005]

SUMMARY OF THE INVENTION As will be described later, the inventors of the present invention have provided test articles in which both the A and B types of bags are provided with measures which are considered to be effective in improving the bottom opening. A comparison test was performed on the test products that had not been subjected to the test, and six types of the test products, and a solution to the problem was found.
In order to solve the above-mentioned problem, a hexagonally-opened multilayer bag according to the present invention comprises a plastic tube having no folds constituting an innermost layer of a bag body and a layer on which the plastic tube is overlapped, and one end portion on one wall side. At the other end, the one end of the cylindrical body partially adhered to both wall sides is heated and pressurized, and the end of the innermost plastic tube is heat-sealed and closed. The end is unfolded about a first fold line parallel to the edge to form an unfolding portion having triangular folds at both corners, and the fold line is formed at symmetrical positions on both sides of the first fold line. A hexagonal-bottom opening multilayer bag with a parallel second fold line, an outer portion thereof bent inward along these second fold lines, overlapped and adhered to form a bottom portion, and the other end opened. At one end, a plastic tube is connected to the bag wall on the side where the bottom is folded The plastic tube bends in a U-shape along a first fold line of the bag wall and then in an inverted U-shape along a second fold line of the same bag wall when the ends are unsealed and the ends are opened; In addition, both surfaces of the plastic tube are partially adhered to an adjacent layer at an intermediate position between the opening edge of the bag and the first folding line and a position on the opening end side adjacent to the first folding line.

The plastic tube may partially adhere to an adjacent layer between the first fold line and the second fold line of the bag wall on the side where the bottom is folded. The partial adhesion between the adjacent layers may be performed, for example, by selecting the type of adhesive or by appropriately treating any of the adhesive surfaces, so that the contents are filled and then peeled off by the stress during cargo handling.

The cylindrical body constituting the hexagonal-bottom opening multilayer bag of the present invention may be one having both ends cut linearly, or one end (opening end) may be linear and the other end may be linear. What cut | disconnected the edge part (the edge part used as a closed end) stepwise may be sufficient.

The partial adhesion between the adjacent layers may be partially or entirely a part of a plurality of filaments extending in the longitudinal direction of the bag body and parallel to the width direction. Also, the plastic tube is preferably a seamless tube,
A flat long sheet may be attached to the body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a development view (as viewed from the inner surface) before a cylindrical body constituting a hexagonal-bottom opening multilayer bag according to an embodiment of the present invention is cut to a fixed size, and FIG. A partially enlarged plan view in which the lower end of the formed cylindrical body is hexagonally formed by sticking the body, and FIG. 3 is a hexagon formed by folding and closing the open end of the cylindrical body shown in FIG. FIG. 4 is a vertical sectional view of a hexagonal-bottom opening multilayer bag having the hexagonal bottom shown in FIG. 3 according to one embodiment of the present invention.

In the drawing, reference numeral 1 denotes a bag or cylindrical body, 1a denotes a front wall, 1b denotes a rear wall, 2 denotes an innermost plastic tube, 3 denotes a paper layer constituting an outer layer, and 4,5 denote interlayer bonding. ,
6 is a heat seal, 7 is a first folded line, 7a is a first front wall.
Fold line, 7b is the first fold line on the back wall, 8 is the second fold line, 8a is the second fold line on the front wall, 8b is the second fold line on the back wall, 9 is the bottom adhesive, 10 is the triangular fold, 11 , 12, and 13 are interlayer adhesives, 14 is a body glue, 14a is a body sticking part, C is a scheduled cutting line, F
Is a side folding line of the cylindrical body.

As shown in FIG. 1, a tubular body 1 is composed of an innermost plastic tube 2 and a paper layer 3 made of, for example, kraft paper, which is superposed on the outer side thereof. The plastic tube 2 and the paper layer 3 are partially adhered in a dotted manner at interlayer adhesive portions 4 and 5 with the cut line C interposed therebetween. Interlayer bonding part 4
Is located at the opening end when the tubular body 1 is cut along the planned cutting line C, and is applied over the entire width of the paper layer 3 and is completed as shown in FIG. At the open end of the body 1, the inner and outer layers are partially bonded on both the front wall 1a and the back wall 1b. The interlayer bonding portion 5 is formed by cutting the cylindrical body 1 with the cutting line C.
Located at the closed end when cut along. In FIG. 1, the adhesive is applied only to both sides except for the central portion of the paper layer 3, that is, the portion overlapping with the plastic tube 2, so that as shown in FIG. At the closed end, the inner and outer layers are partially bonded only at the back wall 1b. At the same end, the plastic tube is closed by heat sealing (6).

The bag material shown in FIG. 1 is folded along the side folding line F of the tubular body, and is attached to the body with the body glue 14, thereby forming the tubular body 1 having no folds. The wall without the body sticking part 14a becomes the front wall 1a, and the wall with the body sticking part becomes the back wall 1b. As shown in FIG. 2, the formed tubular body 1 is opened by folding back a back wall 1 b at an end serving as a closed end thereof along the first folding line 7 (more precisely, 7 b) to the opening end side. Then, a hexagonal opening part having the triangular folding part 10 is formed at both ends. In this case, the plastic tube 2 is partially bonded at the closed end to the paper layer 3 on the back wall by interlayer bonding 5, so that it is folded back together with the back wall 1b, and in FIG. Located in half.

As shown in FIG. 3, the open end is folded along two second folding lines 8 a and 8 b and closed by an adhesive 9. As shown in FIG. 4, the plastic tube 2 is formed into a U-shape along the first folding line 7b of the back wall 1b, and then to the second folding line 8b of the same bag wall, as shown in FIG. It is bent in an inverted U shape along. The above configuration is not different from the hexagon-bottom opening multilayer bag (A type) provided with the conventional plastic tube inner bag described above and shown in FIG.

The features of the present invention are shown in FIGS.
This is the point where interlayer bonding indicated by reference numerals 11 and 12 is performed.
The interlayer bonding portion 11 is located substantially in the middle between the interlayer bonding portion 4 and the first fold line 7, and the interlayer bonding portion 12 is adjacent to the first fold line 7,
It is located on the opening end side. As shown in FIG. 1, the pattern of the interlayer (partial) adhesive portions 11 and 12 is, for example, a plurality of lines extending in the longitudinal direction of the bag body 1 and parallel to the width direction. Glued to layer 3.

Another embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a developed view corresponding to FIG. 1 of the first embodiment shown in FIGS. 1 to 4, and FIG. 6 is a longitudinal sectional view corresponding to FIG. (Note that the drawings corresponding to FIGS. 2 and 3 are completely the same as those in FIGS. 2 and 3, respectively, and are not shown.) The reference numerals in the drawings have the same meanings as in FIGS. Reference numeral 13 denotes an additional interlayer bonding. Except for the interlayer bonding 13, there is no difference in the other configuration from the first embodiment, and a detailed description thereof will be omitted.
The interlayer adhesive 13 is formed by joining the plastic tube 2 and the paper layer 3 in the longitudinal direction of the bag 1 only on the back wall 1b side between the first fold line 7 (exactly 7b) and the second fold line 8 (exactly 8b). And adheres in a plurality of lines parallel to the width direction.

[0016]

As described above, the inventors of the present invention
9 (A type) and two types of conventional products shown in FIG. 11 (B type), FIG. 4 (hereinafter referred to as A1 type), FIG. 6 (hereinafter referred to as A2 type), and FIG. 7 (hereinafter referred to as B1 type) ) And FIG. 8 (hereinafter referred to as B2 type) were subjected to a filling test, and the opening speed of each bottom, the opening degree, and the degree of clogging of the contents in the corners of the bottom were compared. As is clear from FIG. 7, the B1 type has a configuration in which interlayer adhesives 11 and 12 are applied to the bag body of the conventional product B type, similarly to the A1 type. As shown in FIG. 8, the B2 type is a conventional type B type bag body.
As in the case of the A2 type, the interlayer bonding 11, 12 and 13 are applied, but the interlayer bonding 13 is made only by the inner layer plastic tube 2 and the paper layer 3 constituting the outer layer only on the front wall 1a side of the bag body. It differs from the A2 type in that it is adhered.

Each of the test products is composed of a seamless tube having a low-density polyethylene of 50 μm thickness in the inner layer and a kraft paper of 84 g / m ² in the outer layer.
The bag length was 730 mm and the bottom width was 120 mm. The interlayer bonds 4 and 5 are applied in the form of dots having a diameter of 10 to 15 mm according to a conventional method. The length of the interlayer adhesive 13 is about 30
mm, and 50 mm apart from each other.

The packing used in the test was a commercially available specific gravity of 0.1.
92 low-density polyethylene pellets, the filling amount is 25 kg per bag, and the filling method is 1.5 m above the bag bottom.
It was allowed to fall naturally through a funnel with a diameter of 180 mm at the outlet.
As a result, in the A1 type, the opening speed of the bottom, the opening degree, and the degree of clogging of the contents at the corners of the bottom were all significantly higher than those of the conventional product. The A2 type gave almost the same results, but the B1 type and B2 type
None of the types clearly exceeded the level of conventional products. As described above in detail, according to the present invention, it is possible to provide a hexagon-bottomed multilayer bag having an inner bag in which the bottom of a plastic tube is heat-sealed in the innermost layer, which has good bottom opening.

[Brief description of the drawings]

FIG. 1 is a development view seen from the inner surface side before a cylindrical body constituting a hexagonally-opened multilayer bag according to an embodiment of the present invention is cut to a fixed size.

FIG. 2 is a partially enlarged view of a state in which the lower end of a cylindrical body formed by pasting the bag material of FIG.

3 is a partially enlarged view of a hexagonal bottom formed by folding and closing an open end of the tubular body shown in FIG. 2;

FIG. 4 is a longitudinal sectional view of a hexagon-bottom opening multilayer bag according to an embodiment of the present invention having the hexagonal bottom shown in FIG. 3;

FIG. 5 is a development view (as viewed from the inner surface side) before a cylindrical body constituting a hexagonal-bottom opening multilayer bag according to another embodiment of the present invention is cut to a fixed size.

FIG. 6 is a longitudinal sectional view of a hexagonal-bottom opening multilayer bag formed from a tubular body formed from the bag material of FIG. 5;

FIG. 7 is a longitudinal sectional view of a hexagon-bottom-opening multilayer bag of a comparative example used in a comparative test for confirming the bottom-opening property of the hexagon-bottom-opening multilayer bag of the present invention.

FIG. 8 is a longitudinal sectional view of a hexagon-bottom-opening multilayer bag of another comparative example used in a comparative test for confirming the bottom-opening property of the hexagon-bottom-opening multilayer bag of the present invention.

FIG. 9 is a vertical cross-sectional view of a prior art hexagonal bottom open multilayer bag.

FIG. 10 is a partial enlarged plan view of the open end before folding and closing the bottom of another prior art hexagonal bottom opening multilayer bag different from FIG. 9;

FIG. 11 is a longitudinal sectional view of the hexagonal bottom opening multilayer bag in which the open end portion shown in FIG. 10 is folded and closed.

[Explanation of symbols]

1: bag or cylindrical body, 1a: front wall, 1b: rear wall,
2: (most) inner layer, 3: outer layer, 4: interlayer bonding, 5: interlayer bonding, 6: heat sealing, 7: first fold line, 7a: first fold line of front wall, 7b: first fold line of rear wall , 8: second folding line,
8a: second fold line of front wall, 8b: second fold line of rear wall,
9: bottom adhesive, 10: triangular fold, 11: interlayer bonding,
12: interlayer bonding, 13: interlayer bonding, 14: body glue, 14
a: body pasting allowance, C: scheduled cutting line, F: side folding line of the cylindrical body.

Claims (2)

[Claims] 1. A pleated plastic tube, which constitutes the innermost layer of a multi-layer bag, is provided at one end only on one wall side with a tubular body superposed on the outside, and at the other end. The end of the plastic tube partially adhered to both sides of the tubular body to the cylindrical body, the end of the plastic tube partially adhered to only the one wall side is closed by heat sealing, and further, the tubular body on the closed side of the heat seal is closed. The end portion is opened around a first fold line parallel to the edge to form an open portion having a triangular fold at both corners, and is parallel to the fold line at symmetrical positions on both sides of the first fold line. A hexagon having a second folded line, an outer portion thereof being bent inward along the second folded line, overlapping and pasting to form a bottom portion, and the other end of the tubular body having an open end. A bottom-opening multi-layer bag, wherein the plastic tube has a closed end on its side. When the end of the tubular body is unfolded, it bends in a U-shape along the first fold line of the multilayer bag wall, and then reverses in a U-shape along the second fold line of the same multilayer bag wall, and A hexagonal bottom in which a wall surface of the plastic tube is partially bonded to an adjacent layer at an intermediate position between the opening edge of the multilayer bag and the first folding line and a position on the opening end side adjacent to the first folding line. Opening multilayer bag. 2. The hexagonal bottom opening multilayer according to claim 1, wherein the plastic tube is partially bonded to an adjacent layer between the first fold line and the second fold line of the cylindrical body on the side where the bottom is folded. bag.