JP2002012232A - Powder leak prevention bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a powder leak without using a plastic film and to recycle a used paper-bag as it is. SOLUTION: In the powder leak prevention multi-structure bag 10, the lower end portions of the inner faces of the innermost layers forming a paper tube 11i are joined together with a thermoplastic resin adhesive 13. Thus, a bottom 14 is formed. The lower portion of the jointed area of a paper tube 11 is sewn. The sewn area is covered with sealing bands 16 and 17 from outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layered powder leakage prevention bag comprising a plurality of paper tubes.

[0002]

2. Description of the Related Art In a paper bag made of kraft paper used for filling powder, for example, a so-called three-layer bag, a multi-layered paper tube is first formed, and the uppermost part is formed with an innermost layer and an intermediate layer if necessary. The outermost layer was glued, the entire bottom of the bag was sewn by sewing, the sewn area was covered with a tape coated with a hot-melt adhesive, and the product was heat-sealed. FIG. 5A is a cross-sectional view showing a three-layer bag 40, a glue 41 having an upper portion glued, a thread 42 having a bottom stitched, and a tape 43. FIG. 6 shows a state where the paper cylinder 44 is expanded.

A three-layer bag having this structure has generally exhibited good powder leakage prevention performance. However, when a powder comprising fine particles such as a certain dye or titanium powder or talc powder is enclosed, a sewing machine is not used. Go through your eyes and tape 4 at the bottom of the paper bag
There was a case where it leaked outside from three parts. The incidence of leaking paper bags is around 1%. However, since it cannot be ignored, prevention of powder leakage is required.

[0004] On the other hand, a synthetic resin layer 45 such as a polyethylene film is also disposed on the innermost layer of a paper bag. FIG. 5B is a cross-sectional view, and the method of forming the bottom is the same as that of FIG. 5A. This type of paper bag is an important waste paper resource, and it is common to reuse it. However, when a polyethylene film or the like is included, it cannot be reused as it is, and even if it is incinerated, it must be treated under conditions different from paper from the viewpoint of ecology, and waste of material and disposal costs is large.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its object is to surely prevent the leakage of powder and to make it possible to recycle used paper bags as they are. That is. Another object of the present invention is to provide a powder leakage prevention bag that can be manufactured in the current bag making process using a cylinder making machine.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made to obtain the same sealing effect without interposing a plastic film between the paper cylinders. The bottom part is formed by bonding the lower end part using a thermoplastic resin adhesive, and the paper cylinder is sewn at the lower part of the bonding part, and the sewn part is covered with a sealing band to constitute a dust leakage prevention bag. We have taken measures.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The powder leakage prevention bag according to the present invention has a multi-layer or multi-layer structure composed of a plurality of paper tubes.
The paper cylinder is a state in which paper is literally made of paper and a paper sheet material is formed into a cylindrical shape by a cylinder making machine. In a so-called three-layer bag, the paper cylinder is tripled. However, according to the present invention,
Needless to say, it is not limited to the layer bag. Although it has already been described that the sealing effect can be improved by interposing a plastic film between the paper cylinders, in the present invention, the same sealing effect as when the plastic film is interposed without the plastic film is obtained. Aim.

[0008] In order to obtain the desired sealing effect, in the case of the present invention, the lower end portion of the inner surface of the innermost paper cylinder is bonded using a thermoplastic resin adhesive to form a bottom portion. Furthermore, the paper cylinder is sewn at the lower part of the bonding portion, and the sewn portion is covered with a sealing band from the outside to complete.

The thermoplastic resin adhesive used for forming the bottom is used as a solution type, an emulsion type or a hot melt type. In the present invention, it is desirably quick-drying for use in a bag making process using a current cylinder making machine. Further, in order to recycle the used paper bag, it is necessary to use an adhesive using a thermoplastic resin which can be easily separated. As a thermoplastic resin adhesive satisfying these requirements, an emulsion-type acrylic resin adhesive, particularly an adhesive classified as a water-soluble modified acrylic resin emulsion, is suitable. An ideal result can be obtained by heating and thermally bonding the bonding points of this type of adhesive.

[0010] This bonded portion is reinforced by sewing.
For this reason, the stitching point is located below the bonding point so that the stitching does not cause a powder leak. The lower portion of the bonding portion may be within the range where the adhesive is applied or may be outside the range. FIG.
reference.

[0011] The sewn portion is further covered with a sealing band from the outside. As the sealing band, one coated with the same hot-melt adhesive as that shown in FIG. 5 can be used. However, in the case of the present application in which a necessary and sufficient sealing effect has already been obtained at the bonding portion, it can be covered with a sealing band using crepe paper or the like. In this case, the crepe paper sealing band is sewn with a suture. It is to be noted that the gluing of the upper part of the paper bag can be performed if necessary, as in the conventional case. The gluing may be an ordinary glue which has been conventionally used and which is inexpensive and does not hinder the recycling of paper bags, for example, starch glue.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the illustrated embodiments. 1 to 4 show a longitudinal section of the three-layer bag 10. The three-layer bag 10 is a triple-layered paper cylinder 11, and is integrated by gluing the outer surface of the innermost layer 11i and the outer surface of the intermediate layer 11h. FIG. 1 (a). Reference numeral 12 denotes a glued portion made of starch glue attached in a broken line. The lower end portion of the inner surface of the paper cylinder of the innermost layer 11i is adhered by an adhesive 13 composed of a water-soluble modified acrylic resin emulsion,
Is formed. The gluing portion 12 may have a broken line shape, but the bonding portion to which the adhesive forming the bottom portion 14 is applied must be a continuous band shape. FIG.

[0013] A sewn place by the suture thread 15 is provided below the bonded part. The illustrated suturing point overlaps the bonding point, and is located at a lower portion in the range where the adhesive 13 is applied.
The suture 15 may be the same as that used in a conventional paper bag. The sealing band covering the suturing portion can be selected from two types. One is a non-sealing sealing band 16 made of crepe paper or the like, and the other is a sealing hermetic band 17. The sealing band 17 is generally a tape coated with a hot-melt adhesive. See FIG. 3 (b). Non-sealing sealing band 1
6 can be attached simultaneously with the formation of the bottom with the suture 15, and the hermetically sealed band 17 can be attached after the formation of the bottom with the suture 15.

When such a bag for preventing powder leakage is manufactured by using a current cylinder-making machine, a bottom 14 is formed at the lower end of the inner surface of the base paper to be the innermost layer 11i. An adhesive 13 made of a modified acrylic resin emulsion "Pegal" is applied. Next, the outer surface of the innermost layer 11i and the outer surface of the intermediate layer 11h of the base paper are glued in a broken line, and longitudinal gluing is performed along the edges of the folded and overlapping paper cylinders in the longitudinal direction. The tube is completed. The adhesive 13 dries before the paper cylinder material enters the cylinder forming section and does not adhere to other parts. FIG. 1B is at this stage.

Thereafter, a heat bonding step is performed on the portion of the paper cylinder 11 on which the adhesive 13 is provided, as shown in FIG.
Further, a suturing process is performed on the suture 15 at the lower portion of the bonding portion (FIG. 3B), and at this time, overtaping, that is, attachment of the sealing bands 16 and 17 is performed outside the suturing portion. Although the sealing band 16 is usually sewn with a suture 15, the sealing band 17 which is hermetic can be attached so as to cover the outside of the portion after suturing with the suture 15. . The completed powder leakage prevention bag 10 has a structure as shown in FIG.

The powder leakage prevention bag 10 according to the present invention can be recycled as it is after use, and even if it is crushed, the water-soluble modified acrylic resin emulsion component can be easily separated by specific gravity separation. When starch paste is used, no problem occurs even in a recycled paper process.

[0017]

Since the present invention is constructed and operates as described above, by using a thermoplastic resin adhesive,
The same sealing effect can be obtained without the interposition of a layer such as polyethylene film, and it is possible to recycle used paper bags as they are and to manufacture them in the current bag making process. It has remarkable effects such as not requiring capital investment.

[Brief description of the drawings]

FIG. 1 (a) is a longitudinal sectional view of a powder leakage prevention bag according to the present invention at a tube-making stage. (B) The longitudinal cross-sectional view of the stage which applied the adhesive similarly.

FIG. 2 is a developed view of the inner surface of the innermost paper cylinder.

FIG. 3 (a) is a longitudinal sectional view of a step of heating and bonding the powder leakage prevention bag of FIG. 1; (B) A longitudinal sectional view of the suturing stage.

FIG. 4 is a longitudinal sectional view of a main part of the completed powder leakage prevention bag.

FIG. 5 (a) is a longitudinal sectional view showing an example of a conventional three-layer bag. (B) A longitudinal sectional view showing another example of the conventional three-layer bag.

FIG. 6 is an inner developed view of the paper cylinder of FIG. 5 (a).

Claims (3)

[Claims] 1. A powder leakage prevention bag having a multi-layered structure composed of a plurality of paper cylinders, wherein an innermost paper cylinder is provided to obtain an equivalent sealing effect without interposing a plastic film between the paper cylinders. The bottom part is formed by bonding the lower end part of the inner surface of the inner surface of the paper using a thermoplastic resin adhesive, and the paper cylinder is sewn at the lower part of the bonding point, and the sewn point is covered with a sealing band. Powder leakage prevention bag. 2. The powder leakage prevention device according to claim 1, wherein the thermoplastic resin adhesive is made of a material that can be separated in specific gravity in a step of regenerating a paper material forming the paper cylinder. 3. The bag according to claim 1, wherein the thermoplastic resin adhesive comprises a modified acrylic resin emulsion.