JPH03176364A - Packaging bag for powder and manufacture of powder packaging bag - Google Patents

Abstract

PURPOSE:To prevent a content from leaking from the sealed part by a method wherein end parts of a tube shaped main body, where top sealing parts confront, are placed together, and a subsidiary tape is placed over the lapped ends, and in addition, a crepe tape is placed on the top of the subsidiary tape, and an adhesive is placed in-between, and the sealed and lapped part is sewn by a sewing thread. CONSTITUTION:Among sealed parts which close both open ends of a tube shaped main body, for a top sealed part in the vicinity of which a tube shaped filling valve is provided, a subsidiary tape 12 is placed on the end parts of the tube shaped main body, and in addition, a crepe tape 14, which is wider than the subsidiary tape, is placed on the top of the subsidiary tape 12. To cope with a leak passage of powder at Bates type seam, double barriers are provided by an adhesive on a powder leak passage at the upper perforation-sealed part. A first barrier is an adhesive layer 11 which is provided between the tip ends of the tube shaped main body 1 and the subsidiary tape 12, and a second barrier is an adhesive layer 11 which is provided between the end of the crepe tape 14 and the surface of the tube shaped main body. Preferably, in addition to these spots, it is desirable to provide a third barrier between the surface of the tube shaped main body 1 and the subsidiary tape 12. Especially for the upper sealed part to which the pressure of air stream is added at the time of filling, it is desirable to provide triple barriers.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a packaging bag for powder having a filling valve. The present invention relates to a powder packaging bag with a filling valve that has a function of preventing the filling material from leaking from the inside of the bag later and has a sealing part of the bag.

[Prior Art] Industrial paper packaging bags are used in large quantities because they are easy to cut and adhere.

Paper packaging bags with filling valves used for filling powdered materials such as cement, flour, and fine plastic powder include check valve type double-end machine-sewn bags, outer valve type double-end machine-sewn paper bags, and outer valve type paper bags. Double-bottomed bags, inner-valve type double-bottomed bags, etc. are known.

However, outer valve type bags require manual labor to insert the filling nozzle and cannot be automatically packaged. Furthermore, after filling the outer valve, it is necessary to seal the bag by folding in the opening of the outer valve or sealing the bag with a seal. Not only is this complicated, but the filling material tends to leak from the outer valve when the filling nozzle is pulled out of the outer valve.

Also, although double-end machine-sewn bags with check valves have the advantage of being easy to make, they have the disadvantage that the check valves are made of paper, so they are not flexible enough and the filling material tends to leak. Furthermore, there is a drawback that the filling material tends to leak from the sealing part through the perforations and out of the bag.

On the other hand, some inner-valve type double-bottomed bags have an inner valve that is a thin polyethylene tube, which prevents the filling from leaking from the filling valve, but the opening ends of the cylindrical body are bent inward. Not only is the bag-making process complicated because it is necessary to attach the inner valve, but also to attach decorative paper, there is a drawback in the bag-making process that it is difficult to attach the inner valve.

[Problems to be Solved by the Invention] The present invention is capable of automatic packaging, which prevents the filling material from leaking from the filling port and from the sealing part. The purpose of the present invention is to provide a paper powder packaging bag with a filling valve.

[Means for Solving the Problem] Under the above circumstances, the inventors of the present invention have produced various prototype bags with a filling valve that do not leak the filling material, and as a result, the tip of the cylindrical filling valve is made of a plastic film. Further, the sealing part of the packaging body is sewn with an adhesive sandwiched between at least the tip of the cylindrical body end of the packaging body and the auxiliary tape, and between the end of the crepe tape and the packaging body surface. The inventors have discovered that the above object can be achieved by creating a structure in which the present invention is completed.

That is, an object of the present invention is to provide a packaging bag for powder as described below.

l A bag consisting of a cylindrical body made of paper, a sealing part that closes both the upper and lower opening ends of the cylindrical body, and a cylindrical filling valve provided near the sealing part at the top and facing inside the bag. and the upper sealing portion overlaps the opposing ends of the cylindrical body,
The overlapping end is covered with auxiliary tape, and on top of that,
Auxiliary tape A crepe tape that is wider than the auxiliary tape is covered, and an adhesive is sandwiched between the tip of the end of the cylindrical body and the auxiliary tape, and between both edges of the crepe tape and the surface of the cylindrical body. The end of the cylindrical body, the overlapping part of the auxiliary tape and the crepe tape are sewn together with sewing thread, and the tip of the cylindrical filling valve inside the bag is sealed. A powder packaging bag characterized by being composed of a cylindrical plastic film.

2. The powder packaging bag according to item 1, wherein the side part of the cylindrical filling valve on the sealing part side is overlapped and closed with the sealing part H of the cylindrical main body.

3. The powder packaging bag according to item 1 or 2, wherein both sides of the cylindrical body are folded inward to form a pair of pleats.

4 The cylindrical body is composed of two or more sheets of laminated paper,
The powder according to ring 3, wherein a plastic film is sandwiched between the laminated papers in the folds of the cylindrical body, and the valve portion at the tip of the cylindrical filling valve is composed only of the plastic film. Sumiyoshi Shun Seibag.

5. Automatically place the packaging bags in Items 1 to 4 on the weighing stand of the powder filling device, then automatically insert the filling nozzle into the filling valve, blow out the powder into the bag using air current, and fill the specified amount. A method for manufacturing a powder package, characterized in that when a weight reaches a weight, the ejection of a filling nozzle is stopped by a signal from a scale stand, the filling nozzle is pulled out, and the powder package is automatically taken out as it is from a powder filling device.

The present invention will be explained in detail below.

The cylindrical body of the present invention is made of paper. Various types of paper can be used, but strong kraft paper, kraft stretch paper No. 1, kraft stretch paper No. 2, wet strength paper, and reinforced paper laminated by coating or laminating plastic are preferred. . This cylindrical body may be made of paper with a double layer, triple layers or more, but it is preferable to use double, triple or more layered paper because of its strength. Alternatively, plastic film may be sandwiched between two or more sheets of paper.

The side portions of the cylindrical body of the present invention may have gusset pleats or may have no pleats, but pleated bags are preferred because of their superior stacking stability.

Among the sealing parts that close both opening ends of the cylindrical body, the upper sealing part where the cylindrical filling valve is provided near the cylindrical body end is covered with auxiliary tape, and further auxiliary tape is placed on top of the auxiliary tape. It is covered with crepe tape that is wider than tape. The width of the auxiliary tape may be longer than twice the length from the end of the cylindrical body to the perforation, but is usually 45 mm to 50 mm.
are used. The width of the crepe tape may be as long as it can be fixed to the surface of the cylindrical body with the adhesive in between, but a width of 50 m + 11 to 55 mm can usually be used.

Note that kraft paper or the like can be used for the auxiliary tape as in the case of the cylindrical main body, and kraft valve crepe, waste paper crepe, etc. can be used for the crepe tape.

Hitherto, such a sealing method using Baler type sewing machine has been used; however, it has the drawback that fine powder leaks between the perforations.

When we investigated the path through which powder leaks from the seams of this baler-type sewing machine, we found that, surprisingly, almost no powder leaked directly from the perforation holes, and that the internal powder was absorbed into the main laminated paper between the perforation holes. It was discovered that the crepe tape leaked through the slit to the upper part of the upper end of the cylindrical body, then through the slit between the auxiliary tape and the bag, and leaked out from the lower edge of the crepe tape.

One of the features of the present invention is that, in response to the powder leakage path of the baler type seam, a double barrier is provided with adhesive in the powder leakage path at the upper perforation sealing part. .

The first barrier is between the tip of the end of the cylindrical body and the auxiliary tape, and the second barrier is an adhesive layer between the end of the crepe tape and the surface of the cylindrical body. Preferably,
In addition to these devices, there is also an upper sealing section where the pressure of the air flow is applied between the surface of the cylindrical body and the auxiliary tape at the third time along the location of the perforation or above or below it. It is recommended to install a triple barrier.

The first barrier shields the upper end of the cylindrical body,
This is the best shielding effect as it directly shields the path of the leaked powder, but even if an adhesive layer is placed in this position, from a mechanical point of view, the upper end will open and peel due to the action of a weak force. It's easy to do. However, in the case of the present invention, since the lower part is firmly fixed by the perforation, there is almost no force to open the upper edge of the cylindrical body, so an adhesive layer barrier is provided at the seam of the upper edge of the cylindrical body. is valid.

The second barrier serves to screen out powder escaping via the perforation holes, which may leak if the first barrier is damaged or slightly leaked.

Further, the third barrier provided as desired functions as a barrier as well as reinforcing the first barrier.

The adhesive may be applied by applying the adhesive to the auxiliary tape and crepe tape to cover them, or by applying the adhesive to the entire surface of the stool tape and crepe tape. The purpose of this adhesive is not for adhesion but for sealing, and by applying this adhesive, even if the filler is fine particles, leakage of the filler from the sealed portion can be prevented.

As the adhesive, various adhesives can be used, including natural adhesives such as starch paste, dextrin, glue, and gum arabic, and synthetic adhesives such as polyvinyl alcohol, vinyl acetate emulsion, polyurethane, and hot melt.

These adhesives may be used alone or in combination of two or more.

Sewing with sewing thread can be done using only sewing thread, but it is best to attach a filler thread to at least one side of the crepe tape and sew over the filler thread with sewing thread to avoid leakage of the filler from the perforation. It is preferable because it has an excellent effect of preventing. Furthermore, after sewing, you can cover the perforations with duct tape or hot adhesive tape.

The cylindrical filling valve is provided in close proximity to the upper sealing portion and extends from the main body surface toward the inside of the bag body.

The cylindrical filling valve only needs to be provided near the sealing part, but it is preferable to fold the lower side part inward and make the folded part part of the cylindrical filling valve because it makes it easier to create the bag. . Furthermore, it is possible to attach a plastic film to a part of this cylindrical filling valve, overlap its upper side part with the upper end of the cylindrical body, and sew it with sewing thread to create the cylindrical filling valve and sealing part at the same time. This is preferable because the process becomes simple.

In addition, attaching the plastic film to the tip of the cylindrical filling valve can be done by fixing it with adhesive, pasting adhesive tape, or
Heat seal and this cylindrical body overlap two or more sheets of paper.
; If it is configured as a laminate, this can be done by various methods such as laminating between the laminate papers and removing the paper at the leading end to leave only the film. The plastic film attached to the tip of the cylindrical filling valve sticks tightly to the filling nozzle due to internal pressure when filling the inside of the bag, and when the nozzle is removed, the films stick together due to the internal pressure, and after filling. Even if the packaging bag is tipped on its side and the powder reaches the valve opening, the weight of the filling material presses the cylindrical plastic film from both sides and seals it tightly, so the powder will not leak out from the tip of the film. .

This plastic film includes cellophane, cellulose acetate, high density polyethylene, low density polyethylene,
Polyethylene such as low density linear polyethylene, polypropylene, polybutene, other polyolefins, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, polyester such as polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyvinyl chloride, polyvinylidene chloride Various plastic films such as polyvinyl alcohol, polyamide, and the like can be used, but a stretched film of high-density polyethylene, which has excellent flexibility and strength, is preferred. The thickness of the plastic film used is 15 to 30 μm if appropriately selected so as to have flexibility.

Note that the cylindrical filling valve may be entirely made of plastic film, but it is important to ensure the strength and stiffness of the filling valve;
In order to withstand the pressure of the filling material, it is preferable to cover the filling valve part with high-strength paper such as Kura 71 paper, and in particular, it is preferable to make it seamlessly integrated with the cylindrical body of the housing body. preferable.

The width and length of the cylindrical filling valve when superimposed may be determined as appropriate depending on the size of the filling nozzle.

The length of the plastic film can be determined as appropriate depending on the size of the filling nozzle, but when filling while removing air from a part of the filling nozzle, the length of the plastic film should be set at 1 part of the filling nozzle diameter so as not to block the air bleed nozzle. /2+20~30mrs
It is preferable to set the filling nozzle diameter to a range of .about.

On the other hand, the lower sealing section may have either a bottom-attached structure or a machine-stitched structure, but a machine-sewn structure is preferable because both sealing sections can be created at the same time with two sewing machines, which simplifies the bag-making process. It is also necessary to provide a first and second adhesive barrier to the sewing machine.

Next, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, a cylindrical body l is shown. The cylindrical body l is made of double kraft paper and is provided with gusset pleats 2.3 on both sides of the cylindrical body l. The pleated portion 2 of one gusset is longer than the open end 4 of the cylindrical body l and has a baler rising portion 5. 30p
m of polyethylene films 6 are sandwiched between them, and the polyethylene films 6 extend 5C11 longer than the baler rising portion 5.

Figure 2 shows that the baler rising part 5 and the polyethylene film 6 extending beyond it are folded inward together with the laminated paper constituting the valve, overlapped with the open end 4 of the cylindrical body l, and sewn with sewing thread. Combined with cylindrical filling valve 8
It consists of In this way, the cylindrical filling valve 8 and the bag sealing part 9 can be created at the same time, so that the bag can be made efficiently with fewer steps. When the bag is filled with the filling, the polyethylene film 6 is compressed from both sides by the pressure of the filling, and functions as a valve. After filling, when the filling nozzle is removed, the polyethylene film 6 first adheres tightly due to internal pressure and closes the filling inlet. Even if the packaging bag is closed, and then the packaging bag is turned sideways, the pressure of the filling material maintains the close contact of the valve, making it possible to completely prevent powder leakage. Therefore, sealing is achieved by simply pulling out the nozzle, and there is no need for pushing the valve into the bag or for heat-sealing the valve opening.

The sealing part 9 of the bag has a cross section as shown in FIG. 3. An auxiliary tape 12 made of kraft paper is covered over the open end 4, and a crepe tape 14 made of paper, which is longer than the auxiliary tape, is further covered thereon. Polyvinyl alcohol adhesive 11 is applied between the tip of the open end 4 of the cylindrical body 1 and the auxiliary tape 12, between the cylindrical body 1 and the auxiliary tape 12 at a position approximately midway between the open end 4 and the sewing thread 13, and It is held between the end of the crepe tape 14 and the cylindrical body 1. The sewing thread 13 is sewn with a guard thread 15 applied thereto. This increases the tightening force, thereby preventing leakage of the filling material from the sealing portion.

The other sealing part 10 of the bag has a cross section as shown in FIG. 3, and is almost the same as the sealing part 9.
The difference is that the adhesive 11 is sandwiched only between the tip of the open end 7 and the auxiliary tape 12 and between the end of the crepe tape 14 and the cylindrical body l. The reason why the sealing portion 9 to which the cylindrical filling valve 8 is attached is provided with adhesive in many places is because the filling pressure is applied more strongly.

When manufacturing a powder packaging body by filling the packaging bag of the present invention with powder, first, the packaging bag for powder of the present invention is conveyed to an automatic filling device on a conveyor, and a robot hand or the like is used to open the filling valve. Place the bag in a predetermined position on the weighing platform with the bag facing up, and mechanically insert the filling nozzle into the opening of the filling valve of the packaging bag. If the tip of the nozzle is slightly tapered, it can be inserted smoothly into the filling valve. Although it depends on the particle size and specific gravity of the powder, it is usually 0.2
Compressed air of about 5 to 0.35 kgG/cm" can be used.

During powder filling, the film at the tip of the filling valve of the packaging bag is in close contact with the periphery of the filling nozzle.

When a predetermined amount of filling is achieved, a signal is emitted from the weighing platform.
The filling nozzle stops ejecting powder, and the filling nozzle is withdrawn.

Even if the filling nozzle is pulled out, the powder does not leak out at all due to the action of the above valve, so the powder package is automatically laid down on the conveyor and stored without sealing the filling port after filling. Transported to warehouse.

〔Effect of the invention〕

As explained above, the bag of the present invention has the advantage that the filling material does not leak from the filling inlet and the sealing part after and during filling with powder, and also has the advantage that the bag does not leak the filling material from the filling inlet and the sealing part after and during filling. It has the advantage of being suitable for manufacturing automatic packaging bodies for fillings, and unmanned packaging processes can be achieved. Moreover, bag making is done through a simple process.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the cylindrical body before sewing,
FIG. 2 is a sectional view of the cylindrical body thereof, FIG. 3 is a plan view of the bag of the present invention, and FIGS. 4 and 5 are sectional views of the sealing part of the bag of the present invention. The code inside is l; cylindrical body;
2.3; Gusset folds, 4; Open end of cylindrical body, 5:
Baler rising part, 6; polyethylene film, 7; open end of cylindrical body, 8; cylindrical filling valve, 9.10; sealing part, l
l; Adhesive, 12; Auxiliary tape, 13: Sewing thread, 14
Crepe tape, 15: Guess thread, 16: Fold line of pleat.

Claims (1)

[Scope of Claims] 1. A cylindrical body made of paper, a sealing part that closes both the upper and lower opening ends of the cylindrical body, and a cylindrical part provided in the vicinity of the sealing part above the sealing part and facing inside the bag. A bag consisting of a filling valve, wherein the upper sealing portion overlaps opposing ends of the cylindrical body,
The overlapping end is covered with auxiliary tape, and on top of that,
A crepe tape that is wider than the auxiliary tape is covered, and an adhesive is sandwiched between the tip of the end of the cylindrical body and the auxiliary tape, and between both edges of the crepe tape and the surface of the cylindrical body. The end of the cylindrical body, the overlapping part of the auxiliary tape, and the crepe tape must be sewn together with sewing thread, and the tip of the cylindrical filling valve inside the bag must be tightly sealed. A packaging bag for powder, characterized in that it is made of a shaped plastic film. 2. The powder packaging bag according to claim 1, wherein the side portion of the cylindrical filling valve on the sealing portion side overlaps and closes together with the sealing portion of the cylindrical body. 3. The packaging bag for powder according to claim 1 or 2, wherein both sides of the cylindrical main body are folded inward to form a pair of pleats. 4 The cylindrical body is composed of two or more sheets of laminated paper,
4. The cylindrical filling valve according to claim 3, wherein a plastic film is sandwiched between the laminated papers in the pleats of the cylindrical body, and the valve portion at the tip of the cylindrical filling valve is composed only of the plastic film. Packaging bag for powder. 5. The packaging bag according to claims 1 to 4 is automatically installed on the scale stand of a powder filling device, and then the filling nozzle is automatically inserted into the filling valve, and the powder is ejected into the bag by air current, A method for manufacturing a powder package, characterized in that when the weight reaches , the ejection of a filling nozzle is stopped by a signal from a scale stand, the filling nozzle is removed, and the powder package is automatically taken out as it is from a powder filling device.