JPH0248360Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a heavy packaging bag for filling and storing grain flour, cement, compound feed, sugar, salt, etc.

[Conventional technology]

Conventionally, heavy packaging bags are made by forming a flat tube using kraft paper, then folding the opening edge of the flat tube to form a square bottom, and pasting decorative paper on the outer surface of the folded square bottom. It was made up of clothes.

[The problem that the idea aims to solve]

However, since such conventional heavy packaging bags are made of kraft paper, they are inevitably breathable and moisture permeable, resulting in the disadvantage that the contents absorb moisture during storage. .

On the other hand, when a heavy-duty packaging bag is simply made of non-breathable material, the air introduced into the bag along with the contents must be degassed when filling the bag (especially when using an automatic filling machine). Therefore, the disadvantage is that the heavy-duty packaging bag expands to its maximum capacity before being filled with a predetermined amount of contents.

Therefore, the inventor of the present invention has conducted various studies in order to provide a heavy-duty packaging bag that eliminates these conventional drawbacks.
The present invention has devised a heavy-duty packaging bag that is moisture-proof and capable of degassing during filling.

[Means to solve the problem]

That is, in the present invention, after making a notch 2 in at least one place on the upper side of the opening of a bag tube 1 having an inner bag made of synthetic resin film, the left and right ends are folded inward while expanding the opening of the bag tube 1. One end is cut to form a pentagonal folding piece part 5 and/or 6 with the remaining piece 2S as a non-inward folding part, and then the back piece 4 and the front piece 3 are sequentially folded to form a square bottom part. , a non-laminated gap portion 7 leading to the outside is formed between the pentagonal folding piece portions 5 and/or 6 and the front piece 3 and the back piece 4 due to the absence of the folding piece 8. It is a packaging bag.

The heavy-duty packaging bag of the present invention is first required to have a synthetic resin film bag as an inner bag. In the present invention, an inner bag made of synthetic resin film refers to a bag made only of synthetic resin film or a bag made of synthetic resin film laminated with kraft paper.

In addition, if the synthetic resin film inner bag of the present invention is formed with an appropriate number of slits at the bottom of the folded corners, air can be removed more effectively during filling, and the inner bag can be removed more easily when filling is completed. Later, the gap between the slits is closed and the slit becomes a mere line, which prevents moisture from entering the bag after filling.
Particularly advantageous results are obtained.

As the synthetic resin film, any moisture-proof synthetic resin film can be used, but a medium-low pressure film such as a 15μ polyethylene film is suitable, for example. In carrying out the present invention, the outer bag is made of breathable kraft paper, etc., as in the past, and the so-called two-layer bag structure is basically used. A multilayer bag such as a three-layer bag structure with an innermost bag may also be used.

Next, in the present invention, a non-laminated gap portion communicating with the outside is an essential requirement in the end laminated portion of the folded corner bottom portion.

〔Example〕

The present invention will be further explained below with reference to the drawings showing embodiments.

First, a bag tube 1 made of the material with upper and lower openings is made into a flat tube as shown in Fig. 1, and then cuts are made from the upper side of the upper opening to mountain fold lines a and b so as to form a pentagonal folded piece. Enter 2.
The length of this cut 2 can be appropriately selected depending on the width of the non-laminated gap to be obtained, but it is usually suitable to be about one third of the distance from the upper side to the valley fold line c. Next, while expanding the upper opening edge of the bag tube 1, fold both left and right ends inward along the mountain fold lines a and b, and fold only the surface portion downward along the valley fold line c. As shown in FIG. 2, a pair of pentagonal folding pieces 5 and 6 are formed at the left and right ends of the front piece 3 and the back piece 4, with the cut remaining pieces 2S serving as non-inward folding parts.
Therefore, the lower parts of the back piece 4 and the left and right pentagonal folding pieces 5 and 6 are folded inward along the valley fold line d by more than 1/2 of the short width of the back piece 4, as shown in FIG. state. Then, surface piece 3
Similarly, the upper parts of the left and right pentagonal folding pieces 5 and 6 are folded inward along the valley fold line e, and 1/2 or more of the short width of the front piece 4 is folded inward, and placed on the folded piece of the back piece 4. By folding them in opposite directions, an overlapping folded corner bottom part as shown in FIG. 4 is formed, and each laminated part except for the non-laminated gap part 7 is fixed with glue as appropriate.

Note that the example described above is an example in which non-laminated gaps are provided in the laminated portions at both ends of the folded corner bottom.
It goes without saying that the non-laminated gap portion may be provided only in one end laminated portion.

[Effect]

In the end laminated part of the folded corner bottom obtained in this way, the cut remaining piece 2S is not folded inward at all, unlike the pentagonal folded pieces 5 and 6, as a non-inward folded part. As a result, due to the absence of the folded piece 8, as shown in FIG.
A non-laminated gap 7 communicating with the outside corresponding to the thickness of the cut remaining piece 2S, in other words, the thickness of the pentagonal folding piece 6 is formed between the surface piece 3 and the pentagonal folding piece 6 and It is formed between the back piece 4 and the pentagonal folding piece 6. As shown in FIGS. 11 and 12, the air P in the heavy packaging bag is vented to the outside through the non-laminated gap 7 formed in the end laminated portion of the folded corner bottom. Ru.

[Effect of idea]

Due to the presence of the inner bag made of synthetic resin film, this invention provides an extremely excellent moisture-proofing effect, and as a result of the non-laminated gap 7 releasing air during filling to the outside, the heavy packaging bag is prevented from being filled with air. Expansion can be prevented. Moreover, when the non-laminated gap 7 is filled with the contents, the laminated part is compressed due to the filling of the contents, and as a result, the gap 7 itself is compressed and closed, preventing moisture intrusion through the gap 7. Fear is hardly acknowledged.

Incidentally, if the overlapping folded corner bottom part is formed according to the conventional method without making the cut 2, it will be as shown in Figs. As a result, as shown in FIG. 10, there is no non-laminated gap, and as a result, there is no choice but to create a heavy packaging bag with no air escape.

Therefore, according to the present invention, it is possible to provide a highly practical heavy-duty packaging bag that overcomes the contradictory technical problems of moisture proofing and air venting.

[Brief explanation of the drawing]

1 to 4 are plan explanatory diagrams showing an example of overlapping folding to form a non-laminated gap, FIG. 5 is an enlarged sectional view of the main part taken along the line A-A in FIG. An explanatory plan view showing an example of folding, Fig. 10 is Fig. 9 B-B
FIG. 11 is a plan view showing the flow of air from the inside of the bag to the outside; FIG. 12 is an enlarged sectional view of the main part of the line; FIG. 12 is a non-laminated gap formed between the pentagonal fold-in piece 5 and the back piece 4 The first diagram showing the air flow in section 7.
FIG. 1 is an explanatory enlarged cross-sectional view of the main part taken along line B-B in FIG. 1...Bag tube, 2...Notch, 2S...Notch remaining piece, 5, 6...Pentagonal folded piece, 7
...Non-laminated gap portion, 8...Folded piece, 9...Bending portion, P...Air.

Claims (1)

[Scope of utility model registration request] After making a notch 2 in at least one place on the upper side of the opening of the bag tube 1 having an inner bag made of synthetic resin film, fold both left and right ends inward while expanding the opening of the bag tube 1, and at least one end. A pentagonal folding piece part 5 and/or 6 is formed with the cut remaining piece 2S as a non-inward folding part, and then the back piece 4 and the front piece 3 are folded semi-overlappingly to form a corner bottom part, and the pentagonal folding piece is formed. A multi-layer packaging bag characterized in that a non-laminated gap 7 leading to the outside is formed between the pieces 5 and/or 6 and the front piece 3 and the back piece 4 due to the absence of the folded piece 8.