JPH04154557A - Paper bag - Google Patents

Abstract

PURPOSE:To provide a paper bag high in strength and not liable to the leakage of its contents and protrusion of the pleats by a method wherein an inner layer consisting of a heat-sealable material is formed into a cylindrical shape, a heat sealing is made after filling the contents and the auxiliary flaps provided at the opening part of the bag body are bent and sealed with a hot melt adhesive agent as the stepped faces. CONSTITUTION:A bag body 13 is provided with a pleated inner cylindrical body 11 consisting of synthetic resin film and a pleated outer cylindrical body 12 consisting of kraft paper. The ends 14a and 15a of auxiliary flaps 14 and 15 the same in width as an outer wall surface are fixedly attached to an outer wall surface 13a on one side of an opening part of the bag body 13. The auxiliary flap 14 extends from the opening edge of the bag body 13 outwardly to the other end 14b thereof and the auxiliary flap 15 is laid over the outside of the auxiliary flap 14 and extends past the end 14b of the auxiliary flap 14 outwardly to the other end 15b thereof. The opening part of the bag body 13 is provided with substantially stepped faces including the opening end part, hot melt adhesive agent 18 is applied to only the stepped faces at the other ends 14b and 15b of the auxiliary flaps 14 and 15 and, after filling the contents, the inner cylindrical body 11 of the opening part is heat sealed to prevent the leakage of the contents and the protrusion of the pleats.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a paper bag, and more particularly to a pleated paper bag with straight cut ends.

(Prior Art) In general, paper bags in which one of the front and rear walls protrudes stepwise relative to the other to form a stepped portion at the end of the bag body constituting the paper bag are disclosed in, for example, Japanese Utility Model Publication No. 57-42824, It is disclosed in Japanese Utility Model Publication No. 58-28977, Japanese Utility Model Publication No. 59-1957, and Japanese Utility Model Publication No. 59-24677, and is well known.

The bottom of this type of paper bag is closed by folding the step surface inward once and adhering it to the outer wall of the paper bag with hot melt adhesive, and the opening is closed by applying hot melt adhesive to the step surface during bag making. The adhesive is applied in advance, and after the contents are placed inside the paper bag, the adhesive is reactivated with hot air and the adhesive is closed by folding.

These step-cut, single-stick paper bags (pinch bags) are used in large quantities because they are simple and extremely easy to seal after filling with the contents, and there is almost no leakage of the contents and no pickpockets. ing.

(Problems to be Solved by the Invention) However, although conventional pinch bags have the above-mentioned advantages, they have a very important problem that they are difficult to open.

In order to eliminate this difficulty in opening, the stepped bottom of the bag body is folded twice so as to be rolled up, and a piece of paper with tampering tape is applied across the rolled up part to close it. It was thought that this closed part could be used as an opening. Indeed, according to this structure, when opening a paper bag, the bag can be easily opened by pulling up the tear tape, tearing off the padding paper in the width direction, and untying the rolled-up portion at the stepped bottom.

However, this proposed paper bag had a fatal problem in that the contents leaked from the bottom closing portion which served as the opening. The cause of this leakage is that no matter how much you fold the bottom part twice to wrap it around, this part is formed in a step-like manner, so there are some parts that can only be bent once. found.

By the way, when closing the bottom end of the bag body by folding it to facilitate opening, the end shape that is less likely to cause leakage is to use a straight cut end. However, considering the continuous manufacturing of the bag body, it is a well-known fact that the mouth side and the bottom side have corresponding shapes, that is, if the bottom side is cut in a straight line, the mouth side will also be cut in a straight line. If you cut the bottom edge straight,
The benefits of traditional oral stepped end closure methods are not available.

The object of the present invention was to solve the problems of the conventional art, and to form a bottom folded closure part that is easy to open and prevents leakage by using a bag body with straight cut ends, and also to form a bottom folded closure part that is easy to open and prevents leakage. It is an object of the present invention to provide a paper bag which can also obtain the advantages of the conventional stepped end closure method.

(Means for Solving the Problems) The paper bag of the present invention includes an inner layer cylindrical body made of a heat-sealable material with straight cut ends, and at least one layer made of kraft paper disposed outside the inner layer cylindrical body. a cylindrical body with straight-cut ends, and a pleated bag body formed by aligning the edges of both cylindrical bodies and assembled together; and a bottom side edge of the lending body at least twice. a bottom closing part formed by folding and surrounding and fixing with a padding paper with an opening tape; one end is glued to the outer wall surface at the mouth side end of the bag body, and the other end is outside from the mouth edge of the bag body. at least one auxiliary flap that protrudes toward the bag body and forms a stepped surface including the mouth end of the bag body;
a true melt adhesive that is applied to at least the auxiliary flag on the stairway surface and is reactivated by heat, and heat seals the opening of the bag main body after filling with the contents, and further inwards in the longitudinal direction from the heat sealed part. A paper bag that is folded and sealed by reactivating the hot melt adhesive with heat.

(Function) According to the paper bag of the present invention, the bottom of the bag body is folded at least twice, and then the paper bag is closed by applying a padding paper, and the bag is provided to the user with the mouth open. Closing the bottom of the bag main body and applying hot melt adhesive to the step surface of the auxiliary flap fixed to the mouth have already been done by bag manufacturers.

Therefore, after filling this paper bag with the contents, the user must heat-seal the inner layer facing surface at the mouth of the bag body, fold it inward in the longitudinal direction from this heat-sealed part, and then hot-melt bond it. reactivate the agent with heat,
The stairway surface of the opening of the bag body is firmly adhered to the outer wall to close it.

(Example) Hereinafter, the paper bag of the present invention will be described in more detail with reference to the embodiment shown in the accompanying drawings.

Before that, a hot melt adhesive that is reactivated by heat is applied to the step surface of the end of the bag body, which is made up of a multi-layered cylindrical body with a step cut end. The method of closing the opening by reactivating the bag, bending the end of the bag body, and completely bonding the staircase surface to the outer wall surface is well known. (3) There is no protrusion of the folds at the mouth, which are the major advantages.

In addition, such paper bags consisting of a plurality of cylindrical bodies with stair-cut ends are called pitch bags, and are already in use in large quantities, and many users have closed the mouth using the above-mentioned closure means. Since we own a specialized machine (top sealer) for this purpose, if this closure method can be applied to this type of paper bag, it will not only solve the problem of strength, but also eliminate equipment costs because the top sealer can be used as is. Very effective.

Therefore, the paper bag 10 (FIG. 1) according to an embodiment of the present invention has an inner layer cylindrical body 11 made of a synthetic resin film such as a polyethylene film, and an outer layer cylindrical body made of kraft paper. 12 (FIG. 2)
The bag body 13 has both ends cut in a straight line. Such a bag body 13 can be easily formed using conventional manufacturing equipment. One end 14a of two auxiliary flaps 14 and 15 having the same width as the outer wall surface is attached to one side outer wall surface 13a at the mouth of the bag body 13.

15a is fixed with adhesive 16. 1 auxiliary flap 1
4 has a length such that the other end 14b protrudes outward from the mouth edge of the bag body 13, and another auxiliary flap 15
is an end portion 14b of the auxiliary flap 14 which is placed overlappingly on the outside of the auxiliary flap 14 and whose other end 15b is inside.
The length is such that it protrudes further outward than the actual length. Furthermore, -@15a of this outer auxiliary flap 15 is not only adhered to the surface of the inner auxiliary flap 14, but also extends beyond one end edge of the auxiliary flap 14 to a position directly opposing the outer wall surface 13a of the bag body 13. From the viewpoint of strength, it is preferable that it is also bonded to the outer wall surface 13a.

In this way, the opening of the bag body 13 provided with the two auxiliary flanges 14.15, including the opening end thereof, is substantially formed into a stepped surface, and the other end 14 of the auxiliary flap 14.15
As shown in FIGS. 1 and 2, the true melt adhesive 18 is applied only to the step surfaces at b and 15b. After filling the contents, the inner layer cylindrical body 11 at the mouth is heat sealed (the area is designated by 1 in Figs. 1 and 2).
7 and a heat-sealed portion is shown as 17' in FIG. 3) to prevent the contents from leaking and to prevent the folds from popping out.

On the other hand, the bottom closure part is attached to the bag body 1 as shown in FIG.
3 is folded at least twice and wrapped and fixed with a cover paper 20 attached with a tear tape 19.

After the contents are put into the paper bag IO through the mouth and the mouth of the inner layer cylindrical body II is heat-sealed, the mouth is closed by a fold line 21 extending from the heat-sealing part 17' inward in the longitudinal direction of the bag body. Fold the opening of the paper bag 10 along
The step surfaces of the other ends 14b and 15b are entirely adhered to the outer wall surface 13b of the bag body 13. As a result, 10 paper bags
After filling with the contents, the mouth closing part is as strong as the conventional one in which the mouth part of the bag main body itself has a stepped surface, and has no leakage and no protruding folds.

In the above-mentioned embodiment, the bag body 13 has an inner cylindrical body 11 made of synthetic resin film and an outer cylindrical body 12 made of kraft paper.
However, as shown in FIG. 5, it may also be made of cloth kraft paper. As described above, this cloth kraft paper consists of a resin stretched tape on the inner surface of the kraft paper 22. The inner surface of the bag body 24 is formed by laminating the woven fabric 23, and therefore the inner surface of the bag body 24 is formed of the woven fabric 23. The rest of the structure is the same as the paper bag of the embodiment shown in FIGS. 1 and 2, so the same reference numerals are given to the same components and the explanation thereof will be omitted.

The embodiment shown in FIG. 2 may be modified with one or more intermediate layers, or the inner layer may be a cylindrical body made of kraft paper laminated, and the outer layer may be a cylindrical body made of kraft paper. Alternatively, an outer layer or an intermediate layer may be added to the embodiment shown in FIG. Alternatively, the inner layer may be a cylindrical body made of laminated kraft paper, and the outer layer may be a cylindrical body made of cloth kraft paper.Furthermore, the auxiliary flap may be made of the same material as the bag body. material may be used.

(Effects of the Invention) As explained above, according to the paper bag of the present invention, the inner layer is a cylindrical body made of a heat-sealable material, the inner layer is heat-sealed after the contents are filled, and the auxiliary material provided at the mouth of the bag body is By making the flap a staircase surface that can be folded and closed with hot melt adhesive, the bag body with straight cuts on both ends can be used as a folding closure that allows the bottom part to be opened easily, making it possible to close the stairway opening using conventional methods. Similarly, it is possible to provide a paper bag that has high strength, is leak-free, and has the advantages of a mouth closure that prevents pleats from popping out.

Furthermore, although a heat-sealing device is added to close the opening, the special closing machine used for conventional paper bags with stair-cut ends can be used as is, so there is no great burden on the user, which has great effects. play.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a paper bag according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view schematically showing a bag body constituting the paper bag shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view schematically showing the mouth closing portion of the paper bag shown in FIG. 1 after being filled with contents; FIG. FIG. 2 is a sectional view similar to FIG. 2, schematically showing a bag body constituting a paper bag according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 10...Paper bag, 11...Inner layer cylindrical body made of synthetic resin film, 12...Outer layer cylindrical body made of kraft paper, 13...Bag body, 14.15...Auxiliary flap,
14b, 15b...Protruding ends of auxiliary flaps, 18.
...Hot melt adhesive, 22...Kraft paper, 2
3... Woven fabric made of stretched tape. 151 Noro - Cause 2 Figure 3 Figure 4 Figure 5 Prisoner

Claims (1)

[Claims] An inner layer cylindrical body made of a heat-sealable material and having a straight edge cut, and at least one layer of a cylindrical body made of kraft paper and having a straight edge cut disposed outside the inner layer cylindrical body; A pleated bag body formed by aligning the edges of cylindrical bodies and assembled together, and a bottom side edge of the bag body folded at least twice and surrounded and fixed with a padding paper attached with opening tape. One end is adhered to the outer wall surface of the bottom closing part and the mouth end of the bag body, and the other end protrudes outward from the mouth edge of the bag body to form a staircase including the mouth end of the bag body. and a hot melt adhesive that is applied to at least the auxiliary flap of the step surface and reactivated by heat, and heat-seals the opening of the bag body after filling with the contents. A paper package that is folded inward in the longitudinal direction from the heat-sealed portion and sealed by reactivating the hot-melt adhesive with heat.