JP4257811B2 - Manufacturing method for bags for packing granular materials - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a granular material packaging bag in which a labyrinth-shaped passage is provided in a seal portion of the bag .
[0002]
[Prior art]
When the rice is shipped, the rice polished by a rice mill is filled into a bag (such as 5 kg or 10 kg), then sent to a predetermined place by a conveyor, and then stacked on a pallet, for example, in six steps. In this case, air is contained in the bag filled with rice, so if the air in the lower packaging does not come out quickly when the upper packaging is stacked, slipping will occur when stacking. Easy to collapse. The packages stacked on the pallet in this way are transported by a forklift and then loaded onto the land transport truck together with the pallet. It is customary to pile up the body in total, for example, 5 levels.
[0003]
Conventionally, in order to avoid load collapse at the time of stacking, an interstitial fused portion such as “----” is formed in a double-line shape such as 2-wire or 3-wire in the seal band at the top or bottom of the bag. Has been made. By appropriately designing the length and gap of the intermittent line fused part “-” and the position and interval of adjacent intermittent lines, the rice grains that are the contents do not pop out during stacking, and only the internal air escapes. Can be. This method of sealing is sometimes called a “maze seal”.
[0004]
[Problems to be solved by the invention]
The above labyrinth seal is convenient because air can be vented simply by devising how to seal the top or bottom of the bag, but it is not possible for rice grains to come out quickly without letting out the rice grains. Surprisingly difficult. This is because, in order to prevent the rice grains from jumping out, the length of the intermittently fused portion “−” is increased and the gap between “−” and “−” adjacent to the left and right Or, the gap between the upper and lower adjacent adjoining fused portions must be made as small as possible, because this will slow down the air escape rate. If the air removal speed becomes slow, the stacking speed on the pallet must be slowed accordingly, so that it takes a long time to stack on the pallet. And even if it is possible to control the stacking speed while looking at the situation when stacking by hand, when loading by robot, unexpected load collapse may occur.
[0005]
According to the study by the present inventors, the air bleeding speed can be increased to some extent by devising the shape and arrangement method of the intermittently fused portion of the maze seal, but the condition that the rice grains do not jump out is Since it must be satisfied, there is an upper limit for the air bleeding speed, and the upper limit could not be exceeded.
[0006]
However, as a result of repeated earnest research after that, the present inventors considered that the reason why it takes time to vent the air is that the front and back sheets constituting the bag are too close in the air passage, The idea was that if this point was overcome, the air bleeding speed would increase.
[0007]
The present invention was made based on such an idea, and as a bag filled with granular materials represented by cereals such as rice, the granular materials are obtained by taking special measures on the labyrinth seal portion. It is an object of the present invention to provide a method for manufacturing a granular material packaging bag that does not pop out and can increase the air bleeding speed beyond the limit that has conventionally been considered as the upper limit of the air bleeding speed.
[0008]
[Means for Solving the Problems]
The manufacturing method of the granular material packaging bag of the present invention,
The front and back sheets (1A) and (1B) are arranged in the horizontal direction so that the side of each sealant layer (1y) faces each other, and sent downstream.
Embossing at a part corresponding to at least a part of the band (2) of at least one of the four sides of each bag (1);
Embossing in this case, interposer with irregularities (8) the front and back of the sheet (1A), the pressing body from the outside of the sheets while interposed between the (1B) (9), (9) And pressing the intermediate body (8) or the pressing body (9), (9) by heating at the time of pressing ,
Forming a seal zone (7) where necessary for each bag (1);
An intermittent line-shaped fusion part (3) is installed in the embossed zone (2), and a non-fusion part (4), which is a gap between the intermittent line-shaped fusion part (3), is provided. To be an air vent passage,
The discontinuous line-shaped fusion part (3) is disposed so that the discontinuous line is oriented in the length direction of the band (2) and is a double or more double line, and
Cut the front and back sheets (1A) and (1B) that have undergone the above process along a predetermined cut line to form individual bags (1) for packaging granular materials ,
It is characterized by.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
[0010]
<Structure of packaging bag obtained by manufacturing method described later >
The bag (1) is made of front and back sheets (1A) and (1B). Front and back sheet (1A),
As (1B), typically, a laminated sheet having a base film (1x) on the outer surface side and a sealant layer (1y) on the inner surface side is used. In addition to the base film (1x) and the sealant layer (11y), other layers such as a vapor deposition layer, a metal foil, a nonwoven fabric, and paper may be included.
[0011]
Here, as the base film (1x), biaxially stretched polyamide film, biaxially stretched polyester film, biaxially stretched polypropylene film, unstretched polyamide film, unstretched polypropylene film, linear low density polyethylene having a relatively high density Examples thereof include a single layer or a multilayer film. The thickness of the base film (1x) is not particularly limited, but is often about 7 to 40 μm.
[0012]
As the sealant layer (1y), a low density polyethylene called LDPE (or LD), a propylene polymer (copolymer or terpolymer) called CPP, and a linear low weight called LLDPE (or LLD). Examples thereof include layers of density polyethylene, an ethylene-vinyl acetate copolymer called EVA, and an ethylene-acrylic acid ester copolymer. The thickness of the sealant layer (1y) is not particularly limited, but is often about 30 to 250 μm.
[0013]
Lamination of the sealant layer (1y) to the base film (1x) (other layers may be added) can be achieved by methods such as dry lamination, extrusion lamination, and coextrusion.
[0014]
When making the bag (1), the front and back sheets (1A) and (1B) are faced to the respective sealant layers (1y) so that the necessary parts (bands on both sides of the bag, Heat seal the bottom or top band).
[0015]
In the packaging bag obtained by the method of the present invention, the band (2) of at least one side of at least one of the four sides of the bag (1) made of the front and back sheets (1A) and (1B) A discontinuous line-shaped fusion part (3) is disposed on the non-fusion part (4), which is a gap between the discontinuous line-shaped fusion part (3). In the case of a vertically long shape, at least one of the four sides is at least one of the top, bottom, right side, and left side (usually one or at most two).
[0016]
The interrupted line-shaped fusion part (3) is usually arranged so that the interrupted line faces in the length direction of the band (2), but can also be slightly inclined. The length of each short line of the interrupted lines can be set as appropriate, but is often set to a length in the range of about 3 to 100 mm, for example. One of a certain length may be used, or a different length may be mixed.
[0017]
It is possible to provide the intermittently fused portion (3) in a single layer in the length direction of the zone (2), but in this case, the sealing strength tends to be insufficient . is 2-wire, so that 3-wire or 4-wire, arranged such that the two-wire or multi-line form.
[0018]
In the present invention, special measures are taken to emboss the front and back sheets (1A) and (1B) of the zone (2) (that is, the labyrinth seal portion).
[0019]
At this time, as a result of embossing, the concave and convex portions (5) and convex portions (6) are formed in the front and back sheets (1A) and (1B) in the fine structure as viewed from the inner surface side of the bag. It is preferable to do. In this case, the concave part (5) of the front sheet (1A) and the concave part (5) of the back sheet (1B), the convex part (6) of the front sheet (1A) and the convex part of the back sheet (1B) ( It is desirable that 6) face each other as closely as possible.
[0020]
<Method for manufacturing packaging bags>
Next, the manufacturing method of said packaging bag is described.
[0021]
First, the front and back sheets (1A) and (1B) are arranged in the horizontal direction so that the respective sealant layers (1y) face each other, and are sent downstream. In a realistic process, one sheet of raw fabric sheet is sent out from the supply roll, half-folded, then half-cut, and thereafter traveled as front and back sheets (1A) and (1B). The front and back sheets (1A) and (1B) are continuously run at a constant speed from the time when the original sheet is fed from the supply roll until it is half-cut. The bag width of the time is set to 1 pitch and the vehicle is intermittently driven.
[0022]
The front and back sheets (1A) and (1B) sent downstream are then embossed. That is, embossing is applied to a portion corresponding to at least a part of the band (2) of at least one of the four sides when the individual bag (1) is formed.
[0023]
The embossing at this time is carried out by pressing bodies (9), (9) from outside of these sheets in a state where the uneven bodies (8) are disposed between the front and back sheets (1A), (1B). The pressing is performed by heating either the interposition body (8) or the pressing bodies (9), (9) during the pressing. As a result, as described above, in the fine structure when viewed from the inner surface side of the bag, the concave portion (5) and the convex portion (6) are formed in the front and back sheets (1A) and (1B). .
[0024]
As a combination of the uneven inclusion (8) and the pressing body (9), (9),
・ The interposer (8) is a heatable metal plate or mold whose surface is uneven, and the pressing bodies (9), (9) are made of elastic bodies such as rubber or elastic like rubber Having a part,
-The inclusion body (8) is a soft nonwoven fabric, woven fabric, knitted fabric, mesh body, sheet-like material, etc. that has thick and slightly rough eyes or irregularities such as punched holes, and press bodies (9), ( 9) is a heatable metal plate or mold,
Etc. can be exemplified.
[0025]
The above-mentioned zone (2), that is, the zone to be embossed, may be in the width direction of the traveling sheet, and in the length direction (in the case of single picking, along the ear end side, in the case of double picking both It may be along the ear end side or along the center line and the ear end side). This is because it depends on how individual bags are taken from the traveling sheet.
[0026]
After the embossing process, a seal zone (7) is formed at a necessary location when it becomes an individual bag (1). The position of the seal zone (7) on the seat depends on how the individual bags are taken, so the zones on the front and back sides of the seats (1A) and (1B), the zone along the center line, etc. Or the width direction of the sheet.
[0027]
Next, an intermittent line-shaped fusion part (3) is installed in the embossed zone (2), and a non-fusion part (a gap between the intermittent line-shaped fusion part (3) ( 4) Make the air vent passage. The method of installing the discontinuous fused part (3) was described above.
[0028]
At this time, the discontinuous line-shaped fusion part (3) is arranged so that the discontinuous line is directed in the length direction of the band (2) and has a double line or more as described above. Set up.
[0029]
Finally, the front and back sheets (1A) and (1B) that have undergone the above process are cut along a predetermined cut line to form individual bags (1). If necessary, trimming is performed in the width direction prior to or simultaneously with the cutting to make a cut or punch in both ear ends and other parts of the front and back sheets (1A) and (1B).
[0030]
<Filling and sealing of contents>
The bag (1) obtained above is filled with particulate matter from the opening side, and then the band of the opening side is heat-sealed. Examples of the granular material include various kinds of grains such as cereals such as rice, beans, seeds, tablet fertilizer, granular feed, beads and small pellets of plastics / ceramics / metal, pet food, and the like.
[0031]
【Example】
The following examples further illustrate the invention.
[0032]
Examples 1-3
FIG. 1 is a front view showing an example of a packaging bag obtained by the method of the present invention, and an enlarged view of a main part is also appended. FIG. 2 is an AA cut end view of FIG.
[0033]
<Front and back sheet (1A), (1B)>
As the front and back sheets (1A) and (1B) for forming the bag (1), the following three types of laminated sheets [1] , [2] and [3] were prepared (DL is a dry sheet ) Meaning of lamination). Bags and packages made of these laminated sheets [1] , [2] and [3] are referred to as Examples 1 to 3, respectively.
[0034]
[1] A linear low density polyethylene (LLD) with a thickness of 80 μm as an example of a sealant layer (1y) on one side of a biaxially stretched nylon 6 film (ONy) with a thickness of 15 μm as an example of a base film (1x) Laminated sheet with dry lamination.
ONy (15) / DL / LLD (80)
[0035]
[2] Linear low-density polyethylene (LLD) with a thickness of 80 μm in which aluminum vapor deposition (VM) is applied to one side of a biaxially stretched polyethylene terephthalate film (PET) with a thickness of 12 μm as an example of the base film (1x) Laminated sheet with dry lamination.
PET (12) / DL / VM-LLD (80)
[0036]
[3] As an example of the base film (1x), aluminum is laminated on one side of a 15 μm-thick biaxially-oriented nylon 6 film (ONy) while extrusion laminating low-density polyethylene (LD) to a thickness of 15 μm. A 12-μm thick biaxially stretched polyethylene terephthalate film (PET) that has been vapor-deposited (VM) is pressure-bonded, and then a low-density polyethylene (LD) is extruded and laminated so as to have a thickness of 15 μm. (1y) A laminated sheet obtained by pressure-bonding a linear low density polyethylene film (LLD) having a thickness of 60 μm as an example.
ONy (15) / LD (15) / VM-PET (12) / LD (15) / LLD (60)
[0037]
<Manufacture of bag (1)>
FIG. 3 is an explanatory view showing a bag manufacturing process. FIG. 4 is an explanatory view showing an example of an inclusion (8) used for embossing.
[0038]
The raw sheet made of the above laminated sheet is fed out from the supply roll, half-folded so that the sealant layer (1y) is on the inside, and then half-cut into sheets (1A) and (1B) on the front and back sides, respectively. In the state where the sealant layer (1y) side of this was separated from the top and bottom so as to face each other, it was allowed to travel horizontally in the downstream direction. The sheet travels continuously at a constant speed until the original sheet is unwound from the supply roll until it is half cut. It was made to run intermittently as 1 pitch.
[0039]
As shown in FIG. 3 (a), an inclusion (8) made of a metal plate with a heating means is arranged in the width direction between the front and back sheets (1A) and (1B), and the inclusion (8) Embossing was performed by pressing the front and back sheets (1A) and (1B) with the respective pressing bodies (9) and (9). As the intervening body (8), one having innumerable irregularities on both sides and the same positions of the irregularities on the front and back sides was used. As the pressing bodies (9) and (9), rubber plates having moderate elasticity were used.
[0040]
As a result of this embossing, as shown in FIG. 2, in the fine structure when viewed from the inner surface side of the bag, the concave and convex portions (5) and convex portions (6) are formed on the front and back sheets (1A) and (1B). Been formed. The concave portions (5) and the convex portions (6) of the front and back sheets (1A) and (1B) almost coincided with each other between the concave portions (5) and the convex portions (6).
[0041]
After performing the above embossing process, as shown in Fig. 3 (b), the band on both ends of the front and back sheets (1A) and (1B) in the overlapping state is side-sealed by the side seal device, and the seal band (7), (7) was formed.
[0042]
Next, as shown in FIG. 3 (c), in the longitudinal direction (2) in which the embossing was performed, an intermittently fused portion (3) was installed in parallel with the two lines by heat sealing. . The first interrupting line is a short line of 3mm width and 40mm length arranged in a straight line with an interval of 15mm. The second interrupting line is one short line with a width of 3mm and a length of 20mm. Three short lines of 3 mm and 5 mm in length are all arranged in a line in this order with a distance of 5 mm, and the distance between the first interrupted line and the second interrupted line Was set to 8 mm. The non-fused portion (4), which is a gap between the intermittent-wire fused portions (3) formed at this time, becomes an air vent passage.
[0043]
Next, as shown in FIG. 3 (d), trimming is performed to cut off both ear ends of the overlapped front and back sheets (1A) and (1B) and the front and back sheets (1A) and (1B). Was cut in the width direction into individual bags (1) .
[0044]
<Packaging body>
Bags of Examples 1, 2, and 3 prepared using the laminated sheets [1] , [2] and [3] , and Comparative Examples 1, 2 and 3 in which only embossing was omitted in Examples 1, 2 and 3 These bags were filled with rice polished by a rice milling machine from the bottom opening, and then the band at the opening was heat sealed.
[0045]
<Deaeration test>
FIG. 5 is a graph showing the deaeration rate measured when a 10 kg weight body is placed on a package filled with 5 kg of rice in each bag, with the horizontal axis representing time and the vertical axis representing deaeration. The speed (the amount by which the plate is lowered) is shown. The reason why the weighted body is set to 10 kg instead of 5 kg is to promote air bleeding.
[0046]
From FIG. 5, in the package using the bags of Examples 1 to 3 obtained according to the method of the present invention, deaeration started as soon as the weighted body was placed, and after about 5 seconds, excess air in the bag It can be seen that is missing.
[0047]
On the other hand, in the packaging body using the bags of Comparative Examples 1 and 2 among Comparative Examples 1 to 3 where no embossing is provided in the maze seal, the plate is almost lowered until about 2 seconds after the weighted body is placed. The initial deaeration is poor, and even if deaeration starts once, the deaeration speed is slightly slower than in the case of the embodiment, and the total time required for complete deaeration is unavoidable. This is because the numerical aperture of the deaeration part is small.
[0048]
Moreover, in the packaging body using the bag of Comparative Example 3 among Comparative Examples 1 to 3, the initial deaeration is poor, with the plate almost not lowered until about 3 seconds after placing the weighted body. Even when the deaeration started, the gas was degassed more slowly than in the case of Comparative Examples 1 and 2, and it took a long time to complete deaeration.
[0049]
Example 4
FIG. 6 is an explanatory view showing another example of the embossing process.
[0050]
In this example, the following embossing method was adopted instead of the embossing method described in FIG. That is, the inclusions (8) made of nonwoven fabric having thick and somewhat rough eyes are arranged between the front and back sheets (1A) and (1B), and the front and back sheets are directed toward the inclusions (8). (1A) and (1B) were pressed by pressing bodies (9) and (9) made of a metal plate with a heating means to form an emboss. Also in this case, the same preferable air bleeding as in Example 1 was achieved.
[0051]
【The invention's effect】
The bag obtained by the method of the present invention is intermittently connected to at least a part of the band (2) of at least one of the four sides of the bag (1) made of the front and back sheets (1A) and (1B). In the bag in which the linear fusion part (3) is disposed and the non-fusion part (4), which is a gap between the intermittent linear fusion parts (3), serves as an air vent passage. (2) In other words, a specific means (an uneven inclusion (8) is interposed between the front and back sheets (1A) and (1B) on the front and back sheets (1A) and (1B) of the labyrinth seal. Thus, a special contrivance is taken that embossing is carried out by pressing bodies (9) and (9) from the outside of these sheets ) .
[0052]
Therefore, in the zone (2) which is the maze seal portion, the concave portion (5) and the convex portion (6) are formed between the front and back sheets (1A) and (1B) to form a structure that does not adhere to each other. When the packages are stacked, the air inside comes out quickly, and the granular material as the contents does not jump out.
[0053]
In addition, the embossing described above can be incorporated into the bag manufacturing process, so that no extra time is required for bag manufacturing.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of a packaging bag obtained by the method of the present invention, and an enlarged view of a main part is also appended.
2 is an AA cut end view of FIG. 1; FIG.
FIG. 3 is an explanatory view showing a bag manufacturing process.
FIG. 4 is an explanatory view showing an example of an inclusion (8) used for embossing.
FIG. 5 is a graph showing the deaeration rate measured when a 10 kg weight body is placed on a package filled with 5 kg of rice in each bag, with the horizontal axis representing time and the vertical axis representing desorption. The air velocity (the amount by which the plate is lowered) is shown.
FIG. 6 is an explanatory view showing another example of the embossing process.
[Explanation of symbols]
(1)… bag,
(1A), (1B) ... Sheets on both sides
(1x) ... base film, (1y) ... sealant layer,
(2)… band,
(3)… interruptible fused part,
(4)… unfused part,
(5)… concave part,
(6) ... convex part,
(7)… seal band,
(8) ... inclusion bodies,
(9)… Pressing body

Claims (2)

The front and back sheets (1A) and (1B) are arranged in the horizontal direction and vertically so that the respective sealant layers (1y) face each other, and sent downstream.
Embossing at a part corresponding to at least a part of the band (2) of at least one of the four sides of each bag (1),
Embossing in this case, interposer with irregularities (8) the front and back of the sheet (1A), the pressing body from the outside of the sheets while interposed between the (1B) (9), (9) And pressing the intermediate body (8) or the pressing body (9), (9) when the pressing is performed,
Forming a seal zone (7) where necessary for individual bags (1),
An intermittent line-shaped fusion part (3) is installed in the embossed zone (2), and a non-fusion part (4), which is a gap between the intermittent line-shaped fusion part (3), is provided. To be an air vent passage,
The discontinuous line-shaped fusion part (3) is disposed so that the discontinuous line is oriented in the length direction of the band (2) and is a double or more double line, and
Cut the front and back sheets (1A) and (1B) that have undergone the above process along a predetermined cut line to form individual bags (1) for packaging granular materials .
A method for producing a bag for packaging granular materials . As a result of the above embossing, in the fine structure when viewed from the inner surface side of the bag, the front sheet (1A) And back sheet (1B) In each recess (Five) And convex part (6) And both sides are formed and the front and back sheets at that time (1A), (1B) Recess in (5), (5) Position and convex part (6), (6) The method for producing a granular material packaging bag according to claim 1, wherein the positions of each other face each other.

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