JP7113499B2 - Multi-layer paper bag that prevents contents from leaking - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-layer paper bag for containing granular materials derived from foods such as rice, wheat, cornstarch, starch, etc., and granular materials such as feed, plastic resin, cement, lime, and carbon black. More particularly, the present invention relates to a multi-layered paper bag having a sealed structure that prevents leakage from the paper bag even if the content to be stored in the multi-layered paper bag is fine grains or is subject to severe impact during the manufacturing process or transportation.

Various proposals have been made for technologies to prevent the contents of paper bags from leaking out of packaging bags. Although there are products on the market that aim to completely prevent the leakage of the contents even when encountering a In reality, it is difficult to achieve

The present applicant has also made various proposals to solve the above technical problems, and one end of them is disclosed in Japanese Patent Application Laid-Open Nos. 2004-99091 (Patent Document 1) and 2004-99092 (Patent Document 2). is disclosed.

In Patent Document 1, a paper-like tube made of a multi-layered paper-like material is flattened, folded portions are formed at both corners of the opening end of the paper-like tube, and one of the upper paper and the lower paper is opened. The outer layer of the paper-like tube is formed with one or more slits intersecting the creases located in the folds, and the upper and lower sheets are provided with creases so as to close the opening at the center of the developed surface. It is provided on the paper-like material, and in that state, the upper and lower papers are folded along the creases and pasted together, and then the decorative paper is further pasted on top of it to give flexibility and flexibility to the paper-like material around the slit. As a result, the gap becomes narrower, and the pasting agent used after filling the contents gets caught in the gaps and penetrates into the inner layer and hardens, so even minute contents do not leak out.

In addition, for the same purpose as in Patent Document 1, Patent Document 2 also discloses a technique in which a paper bag is filled with contents, and in particular, a technology for suppressing leakage of powder particles in a fine powder state to the outside. there is
The technology disclosed in Patent Document 2 differs from the technology disclosed in Patent Document 1 in that the slits are formed in positions different from those disclosed in Patent Document 1, and one or more slits that are in contact with the opening end without being in contact with the creases located in the folded portion are formed. to form

The techniques disclosed in Patent Literature 1 and Patent Literature 2 have a high degree of contents leakage prevention effect, are patented, and are highly evaluated in the industry.

However, in recent years, technological development and the diversification of distribution forms in transportation have progressed, and the contents filled in paper bags are subject to impact under any conditions, such as working conditions in the manufacturing process, temperature conditions, and road conditions during transportation. There is a growing demand to be able to deal with this without leakage.

From this point of view, we have been trying to provide products to customers without leakage in the state of being filled with fine-grained contents, after using the above-mentioned Patent Documents 1 and 2. In some cases, road conditions and temperature conditions are more severe than expected. There is a current situation where proposals for paper bags are required.

Therefore, in the process of re-testing using Patent Document 1 and Patent Document 2, the present inventors sought a higher level of content leakage prevention function, and under any severe conditions, the content was fine powder. Even if there is, we searched for a technique that can reliably prevent leakage to the outside, and have completed the present invention.

Japanese Unexamined Patent Application Publication No. 2004-99091 JP-A-2004-99092

As described above, the inventions disclosed in Patent Document 1 and Patent Document 2 both prevent leakage at a high level even if the contents of the paper bag are fine powder. If the road conditions are extremely bad when transporting the product to the customer after filling the contents of the paper bag, it may not be possible to completely achieve the purpose in terms of preventing leakage of the contents. The present invention has been achieved by looking directly at the problem and seeking a sealing structure for a paper bag that does not cause leakage of contents under any adverse conditions.

The present invention has been proposed to achieve the above objects, and is characterized by the following configuration.

That is, according to the present invention, both ends of a multi-layered tubular body having at least the outermost layer made of a paper layer are flattened, and the two corners of the open end of the tubular body are placed through the central opening (straight line). , forming a developed surface having a triangular folded part including the upper and lower sheets, and forming a slit parallel to the opening from the inner end of the developed surface of the straight contact part in the outermost layer A multi-layer paper bag is provided.

Further, according to the present invention, the intermediate portions of the upper and lower sheets are folded inward to form a crease (two streaks) for covering the central opening, The multi-layered paper bag is provided by forming a slit parallel to the opening from the inner end of the developed surface on the two lines.

In addition, according to the present invention, an inner patch having a size to cover the central opening is provided between the central opening and the overlapping surfaces of the upper and lower sheets for inserting a content filling nozzle. It is preferable that a one-round valve, the entire inner circumference of which is coated with a hot-melt adhesive, is adhered to the inner surface of the inner patch on the inner surface of the inner patch on the insertion side of the content filling nozzle.

Further, according to the present invention, a valve paper is adhered in a cylindrical shape to one end of the inner patch covering both folded parts of the developed surface and covering the central opening, and the inner patch and the peripheral edge of the valve paper are attached to the inner patch as described above. It is possible to employ a configuration in which the opening end of the paper-like tube is closed by adhering it to the development surface, and the space between one end of the inner patch and the valve paper serves as a filling port.

Further, according to the present invention, after the formation of the slit of the one streak portion and/or the formation of the slit of the two streak portions, the side end portion including the slit of the developed surface is mountain-folded outward with a width of 20 mm or less. The above multi-layer paper bag is provided.

Further, according to the present invention, there is provided the multilayer paper bag having an outer patch (strength paper) in which perforations are cut in the opening direction on the outer surfaces of the upper and lower papers on the opening side constituting the paper bag. .

Further, according to the present invention, there is provided the multi-layered paper bag in which the perforations are formed in at least two rows from one lateral end of the outer patch (strength paper) to the other lateral end.

Further, according to the present invention, there is provided the multi-layered paper bag in which the intervals between the rows of perforations are formed to be 8 mm or more.

Further, according to the present invention, there is provided the multi-layered paper bag in which the outer patch (strength paper) has the fiber components that are made into the paper during papermaking aligned in the direction in which the perforations are drawn.

The effects of the present invention are as follows.
That is, the object of the present invention is to provide a multi-layered paper bag in which at least the outermost layer is made of a paper layer, filled with a content containing fine particles, in handling conditions during assembly work or transportation conditions, unexpected To provide a paper bag having a sealed structure capable of preventing contents from leaking even when subjected to such an excessive impact. Even if the laminated structure of the multi-layered paper bag is partially separated during the work such as folding, the lamination agent in a softened state will enter the part and the layer will be separated from the separated part. In order to prevent the contents from leaking, a slit is formed in advance in the paper layer at the part where the leakage is most likely to occur.

In Patent Document 1, the inventors of the present invention set the position where the slit is formed at a position that intersects the creases of the upper and lower sheets. Although a slit is provided to reach the opening end in a state, when it encounters an excessive impact, although it is slight, a step occurs at the relevant part, and the filling leaks from there. As a result of accumulating research and experiments to solve the problem, we found that the slits to be inserted into the paper layer are formed at least from the inner end of the development surface of the outermost layer to the center opening (hereinafter sometimes referred to as "straight line"). It has been found that perfect sealing can be obtained by forming parallel to .

According to the multi-layered paper bag of the present invention, even if the content is fine granules, even if an excessive impact is encountered, a softened lamination agent will remain at the stepped portion due to the peeling of the creases of the paper layer. A sealed state can be formed to reliably prevent the contents from leaking.

In addition, according to the paper bag of the present invention, by using an outer patch with perforations instead of the opening tape used for opening, there is no generation of fine powder when opening, and the material cost is reduced. can be easily and completely unsealed without leakage of contents while saving the cost.

The configuration of the present invention will be described in more detail below with reference to the drawings.
As described above, the multilayer paper bag (1) of the present invention is prepared by flattening both ends of the multilayer tubular body (2), at least the outermost layer of which is a paper layer, to form the open end of the tubular body (2). Formed on both corners of the part is a development surface (7) having a triangular folded part (10) containing the upper paper (6) and the lower paper (7) through the central opening (8) , a slit (5) is formed parallel to the center opening (8) from the end (8a) of the developed surface of the outermost layer.
FIG. 1 is for explaining the construction of a multi-layered paper bag in which the outermost layer is a paper layer in the construction of the multi-layered paper bag (1), and does not include the inner layers other than the outermost layer.

In the multi-layer paper bag in which the outermost layer is a paper layer in the present invention, a layer that is joined to the paper layer forming the outermost layer due to excessive impact during the manufacturing process of the paper bag or the transportation process after manufacturing (for example, , kraft paper, resin sheets, or laminated sheets of them) may partially delaminate, creating a step at that part, which will impair the sealing performance of the bag, and gradually It was confirmed that leakage of the contents resulted.

The inventors of the present invention have repeatedly conducted experiments to find out which part of the bag the above phenomenon is brought about, and found that the central opening (8) in the triangular development surface (7), that is, the peeling of the laminated structure in one line Since it has been confirmed that the generation of steps is the most conspicuous, we have continued research on countermeasures. As a result, a slit (5) is formed at the edge (8a) of the developed surface that abuts on the center opening (8) of the paper layer constituting the outermost layer, and the joining process of the paper bag is performed at this slit (5). It was found that the softened laminating agent used in (1) enters into the bag, thereby eliminating the step and maintaining the sealability of the entire bag.
Adhesives such as polyvinyl alcohol, polyvinyl acetate, acrylic resins, rubbers, and starch pastes are used as laminating agents used for joining multilayer paper bags.

As described above, in Patent Document 1, the slits are formed in a state not in contact with the creases of the upper and lower sheets. A slit is formed, but by forming a slit parallel to the central opening, which is not suggested in the patent document, as the slit formation site and shape, it is possible to obtain a sealing performance that exceeds the above-mentioned conventional technology. Being able to do so should be considered a remarkable effect.

In the present invention, as described above, a slit (5) parallel to the central opening (8) of the paper layer constituting the outermost layer is formed to obtain a high degree of sealing performance. The developed surface inner end (9b) of the folded line (9a) of the paper (6) and/or the lower paper (7) (hereinafter, this part may be referred to as "two lines") is also parallel to the central opening. A slit (5a) may be formed. Although the length of the slit is not particularly limited, it has been confirmed that the length of the slit is about 10 mm, and that the softened adhesive patch enters this portion to maintain a sufficient sealing performance.

In order to insert a content filling nozzle between the surface of the central opening (8) and the overlapping surfaces of the upper paper (6) and the lower paper (7), a nozzle having a size to cover the central opening is inserted. An inner patch (11) may be loaded (see Figure 3).
In that case, it is necessary to secure a filling port (12) into which a content filling nozzle is inserted between the inner patch and the central opening. The outer end of the valve is located outside the outer end of the inner patch, so that the inner patch cannot be damaged by the nozzle when the nozzle is inserted. There is no

The one-round valve is usually made of flexible paper, and the entire inner circumference is coated with a hot-melt adhesive. That part is blocked.
Also, a well-known closing valve may be used in place of the one-circle valve.

Further, in the present invention, there is provided a paper bag obtained by mountain-folding the side end portion of the unfolded surface outward with a width of 20 mm or less after forming the slits on the one streak portion and/or after forming the slits on the two streak portions. can do FIG. 2 shows a state in which the side end portions of the developed surface are mountain-folded outward after the formation of the two lines, and the folded portion of the developed surface is indicated by reference numeral (5b).
By doing so, not only is the content leakage effect maintained, but also the folded portion becomes pocket-shaped, so even if there is foreign matter from the outside, the unfolded surface folded portion (5b) forms a pocket-shaped gap. Since it is , it is possible to prevent the situation of entering the part and mixing into the bag.

An outer patch (13) for opening can be attached to the outer surfaces of the upper and lower papers constituting the opening side of the paper bag of the present invention (see FIG. 4).
As an outer patch for opening, there is known one in which a tear tape, which has been used as an opening means for paper bags, is attached to the surface of the outer patch. It is recommended that perforations (14) are engraved directly on the outer patch surface that closes the .

Instead of using the opening tape, the outer patch is directly perforated, and the top paper formed in the opening is folded, so that the opening tape is used. In other words, it can suppress the generation of fine dust caused by tearing the tearing tape, so it can be prevented from being mixed into the product, and the outer patch itself is only perforated. Therefore, it is found to be economically superior in terms of suppressing the material cost.

The perforation in the present invention may be intermittently cut at any point of the outer patch. Anything that can be done is acceptable. Also, the arrangement of perforations is at least one row, most preferably two rows. Moreover, when the perforations are arranged in two or more rows, the distance between the rows is preferably 8 mm or more. If the distance between the rows is 8 mm or less, there is a risk that the parallel perforations will interfere with each other due to an unexpected impact or the like, resulting in breakage from that portion. In the present invention, perforations are generally used that are formed over the entire outer patch from end to end in the tearing direction.

Alternatively, if it is desired to dispense the contents of the bag, perforations may be formed only in the central portion of the outer patch, such as a fish hook shape.

Further, various shapes of perforations can be applied according to the contents of the bag, but when the perforations are formed in two rows, the opening operation can be performed smoothly.
As can be seen from the example of FIG. 5, when two rows of perforations are provided to the edge of the outer patch, it is preferable to form a notch for starting tearing at the edge of the perforation.

In the example shown in FIG. 5e, half-cut perforations that do not penetrate from the front surface to the back surface of the outer patch are engraved, and perforations that do not penetrate from the back surface to the front surface of the outer patch are engraved.

Regarding the paper strength of the outer patch used in the present invention, the one used for the tear tape having a certain basis weight can be used without particular limitation, but in the present invention, the most preferable outer patch is the one used. is to use a sheet in which the fibers constituting the outer patch are made in the same direction as the perforations.

In other words, the outer patch is obtained by making paper from a raw material containing fibers such as kozo and mitsumata. This is the most preferable one because the occurrence is suppressed and the operation is performed smoothly.

A die-casting technique is generally applied to engrave perforations in the outer patch. In this case, recessed perforations are formed on the surface of the other calender roll corresponding to the perforations protruding on the surface of one calender roll. The patch is perforated as the calender roll rotates.

FIG. 2 is a plan view showing the configuration of the paper layers forming the outermost layer of the multilayer paper bag according to the embodiment of the present invention; FIG. 10 is a plan view showing a form in which the slit portion is mountain-folded at right angles to the central opening in the present invention; Fig. 10 is a plan view showing an example of a content-filling portion in the multi-layered paper bag defined in claim 3 of the specification of the present application; Fig. 2 is a plan view showing a state in which an outer patch for opening the multilayer paper bag of the present invention is attached in advance to the outer surface of the opening portion; FIG. 2 is a plan view showing an example of a perforated state that can be preferably used as an outer patch for unsealing in the present invention.

Specific embodiments of the present invention will be described below.

In Example 1, as the paper bag, a multi-layer tubular body was used, which had an outer layer made of kraft paper, an inner layer laminated thereon made of polyethylene film, and an innermost layer made of kraft paper.
Both ends of the multilayer cylindrical body used were flattened, and as shown in FIG. A developed surface having a triangular folded portion including is formed.
Due to this operation, in the process of integrating the inner layer and the outer layer in a state where they are partially bent, the bent portion is partly peeled off and a step is generated, and the content leaks from this stepped portion. was accepted.
Therefore, in this embodiment, as a measure to prevent leakage, a slit having a length of 10 mm is formed parallel to the opening from the inner end of the development surface of the straight contact portion in the paper layer, and the multilayer tubular body is integrated. . The obtained paper bag was filled with finely powdered wheat flour, and the process of integrating the paper bag was carried out. agent) got into the stepped portion to eliminate the peeling state, and a sealed multi-layered paper bag could be obtained.
In addition to the drop test (50 bags × 3 times) of the paper bags filled with the contents obtained in this way, the 50 filled bags were placed on a pallet and transport tests (between Chiba → Tokyo, Hyogo → Okayama, Hyogo → Kagawa) : rocking state) was actually implemented. As a result, no breakage of the bag and leakage of the contents were observed.

In the two streaks of the multilayer paper bag obtained in Example 1 above in the unfolded state, a 10 mm long slit is formed parallel to the opening from the inner end of the unfolded surface of the two streak contact portion to prevent the contents from leaking. Further strengthened the measures.
In Example 2, a paper bag was produced by mountain-folding the side ends of the developed surface outward with a width of 6 mm including the slit portion (see FIG. 2). By integrating the inner layer and the outer layer in this state, not only is the content leakage effect maintained, but also the folded portion becomes pocket-shaped, so even if there is fine foreign matter from the outside, this pocket-shaped It was confirmed that it is possible to prevent a situation in which the particles enter the gap and enter the bag.

Although Embodiments 1 and 2 of the present invention have been described above, it should be understood that the specific configuration is not limited to these, and that modifications can be made as appropriate without departing from the gist of the present invention. .

The easy-to-open bag of the present invention can reduce costs due to its simple structure, does not generate fine powder when opened, and completely prevents leakage of the powder content. The availability is extremely high when it is desired to easily and completely open the package while being sufficiently satisfied with the required strength.

1 multi-layered paper bag 2 multi-layered cylindrical body 3, 4 folding line 5 slit (straight line)
5a slit (two lines)
5b Developed surface folded part
6 Upper paper 7 Lower paper 8 Center opening 8a Inner edge of developed surface (straight line)
9 Folded line of upper sheet 9a Folded line of lower sheet 9b Inner end of developed surface (two lines)
10 folding portion 11 inner patch 12 filling port 13 outer patch for opening 14 perforations

Claims (9)

Both ends of a multi-layer tubular body whose outermost layer is at least a paper layer are flattened, and upper and lower paper are included at both corners of the open end of the tubular body through a central opening (straight line). 1. A multi-layer paper bag, characterized in that a developed surface having a triangular folded part is formed, and a slit is formed parallel to the opening from the inner end of the developed surface of the straight contact portion of the outermost layer. At intermediate portions of the upper and lower sheets, fold lines (two lines) are formed to cover the central opening by folding the upper and lower sheets inward. 2. A multi-layer paper bag according to claim 1, wherein a slit is formed parallel to the opening from the inner end of the developed surface. An inner patch having a size to cover the central opening is loaded between the central opening surface and the overlapping surfaces of the upper and lower papers for inserting a content filling nozzle, 3. A multi-layer paper bag according to claim 1 or 2, wherein a one-round valve, the inner surface of which is coated with a hot-melt adhesive, is adhered to the inner surface of the inner patch on the inner surface of the content filling nozzle insertion side of the inner patch. . A valve paper is attached in a cylindrical shape to one end of the inner patch covering both folded portions of the development surface and covering the central opening, and the inner patch and the peripheral edge portion of the valve paper are attached to the development surface, 4. A multilayer paper bag according to any one of claims 1 to 3, wherein the open end of the paper tube is closed and a filling port is provided between one end of the inner patch and the valve paper. 5. The method according to any one of claims 1 to 4, wherein after forming the slit of the one streak portion and/or after forming the slit of the two streak portions, the side end portion including the slit of the developed surface is mountain-folded outward with a width of 20 mm or less. A multilayer paper bag according to any one of the preceding items. 6. The multi-layered paper bag according to any one of claims 1 to 5, wherein an outer patch (strength paper) having perforations cut in the opening direction is provided on the outer surface of the upper and lower papers on the opening side constituting the multilayer paper bag. Multi-layer paper bag. 7. The multi-layer paper bag according to claim 6 , wherein said perforations are formed in at least two rows from one lateral end of said outer patch (strength paper) to the other lateral end. 8. The multi-layered paper bag according to claim 6 or 7 , wherein the intervals between the rows of perforations are set to 8 mm or more. 9. The multilayer paper bag according to any one of claims 6 to 8, wherein said outer patch (strength paper) has a fiber component that is made into paper during paper making and is aligned in a direction in which said perforations are drawn.

Images