JP5249724B2 - Packaging bag manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for manufacturing a packaging bag made of a synthetic resin film for packaging granular materials such as grains, and more specifically, a boundary between a fused portion and an unfused portion of a synthetic resin film. The present invention relates to a manufacturing method and a manufacturing apparatus for a packaging bag that prevent edge breakage that occurs in a section.

Conventionally, grains such as rice sold at supermarkets are displayed in stores in a state of being filled in a packaging bag made of a synthetic resin film such as polyethylene.
These packaging bags are sealed by stacking synthetic resin films by a method called heat sealing or impulse sealing, and energizing with the ends held by heater wires, and softening and fusing the synthetic resin films. The part is formed into a bag shape.

However, this sealing method is performed in such a manner that the synthetic resin film is fused while being pressed by the heater wire and the receiving portion opposite to the heater wire, so that the synthetic resin film is softened by heating where pressure is applied. As shown in FIG. 5B-2, the portion is fused in a state of being crushed in the thickness direction.
And when the pressure which pinches | interposes a synthetic resin film is high, especially the melt | fusion part will become thin and the thin part which stress concentrates in the boundary part with the part which is not fuse | melted will be made. In addition, when a force is applied to the boundary portion during transportation, there is a problem that a so-called edge breakage phenomenon occurs in which the synthetic resin film is easily cut along the boundary portion.

In order to prevent such edge breakage, it is only necessary to reduce the clamping pressure. However, if the clamping pressure is too weak, it is only necessary to sandwich the synthetic resin film between the heater wire and the receiving portion. Since only a slight pressure is applied, if the receiving part or the synthetic resin film has a slight thickness unevenness, the thin part does not have the minimum pressure required to fuse the synthetic resin film, and the seal The fusion of the parts will be incomplete.
In addition, even if there is no thickness unevenness, if an appropriate clamping pressure is set so that a thin portion is not formed on the synthetic resin film, the pressure will be different for each synthetic resin film. The setting of the pressure to be held for each film is changed, and as a result, the manufacturing speed becomes slow and the manufacturing apparatus becomes complicated.
Therefore, in order to complete the fusion of the seal portion, it is necessary to apply a certain clamping pressure to the heater wire and the receiving portion, and as a result, the pressure for clamping the synthetic resin film becomes high, As shown in FIG. 5 (b-2), the synthetic resin film was naturally fused in a state where it was crushed in the thickness direction, and there was a problem that it was easy to form a thin portion in the synthetic resin film. .

  The present invention has been made in view of the above-described conventional problems, and is a packaging bag for packaging granular materials such as grains that can prevent the occurrence of edge breakage while maintaining the strength of the seal portion. The object is to provide a manufacturing method and a manufacturing apparatus.

  In order to achieve the above object, a method for manufacturing a packaging bag according to claim 1 of the present invention is a method for manufacturing a packaging bag of granular materials such as rice and grains. Two or more heater wires for fusing the end portions to produce a seal portion, and a receiving portion arranged so as to face the heater wires, and holding pressure for holding the synthetic resin film between the heater wire and the receiving portion In this case, only the heater wire of the heater wire is energized and the other heater wires are not energized. By receiving the clamping pressure between the other heater wire and the receiving portion, the energized heater wire is not pushed in the thickness direction of the synthetic resin film, so that the synthetic resin film is fused and the sealing portion is not fused. Those that are configured to prevent the thin portion where the stress at the boundary between the synthetic resin film are concentrated is formed.

  The packaging bag manufacturing method according to claim 2 of the present invention is configured such that the heater wire to be energized among the two or more heater wires is selected by a barcode printed on the synthetic resin film. It is.

  The synthetic resin film used in the present invention is not particularly limited as long as it is softened and fused by heating and returns to a film shape again by cooling. For example, polyethylene resin, polypropylene resin, etc. And films made of thermoplastic resins such as polystyrene resin, polyamide resin, polyacetal resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, ABS resin, AS resin, and PMMA resin.

  The synthetic resin film may have any structure as long as it has at least an inner surface made of the above resin and can be fused by heating, or may be a film made of one kind of resin, or a polyamide resin and polyethylene. You may use the composite film with the structure of 2 or more layers produced with 2 or more types of resin, such as resin. Moreover, when using a composite film, the inner surface material should just be in the state which can be fuse | melted, and the outer surface material may use a non-fusing material like paper.

  Furthermore, as the shape of the synthetic resin film used in the present invention, a shape that has been previously formed into a cylindrical shape may be used, or a plurality of synthetic resin films may be stacked to melt three or four sides. You may wear it.

  The heater wire used in the present invention is not particularly limited as long as it generates heat when energized, softens a plurality of synthetic resin films, and fuses the films, for example, heat seal or impulse seal. For example, heater wires used in such cases. In order to prevent the softened synthetic resin film from sticking to the heater wire and preventing it from being removed, it is preferable to cover the surface of the heater wire with a Teflon (registered trademark) sheet or the like.

The heater wire used in the present invention requires two or more heater wires, and it is necessary to energize only arbitrary heater wires and not energize other heater wires.
That is, when there are two or more heater wires, it is possible to make a heater wire that is energized and a heater wire that is not energized, and it is optional by energizing only any heater wire and not energizing other heater wires. Even when the synthetic resin film is softened by energizing the heater wire, the synthetic resin film sandwiched between the non-energized heater wire and the receiving portion does not soften, so there is almost no gap between the synthetic resin films. A state that does not change can be created.
In the present invention, receiving the clamping pressure refers to creating a state in which the interval between the synthetic resin films is hardly changed even when the synthetic resin film is softened by the above-described configuration.
With the above-described configuration, even when the synthetic resin film is softened when energized, any heater wire is fused without being pushed in the thickness direction, and the edge of the sealed portion after fusion is cut. Thus, it is possible to prevent the formation of a thin-walled portion that causes the occurrence of the above.

  Here, when there are two heater wires, one heater wire is energized and one heater wire is not energized, but when there are three or more heater wires, energization is performed according to the desired packaging bag. If heater wires that are not used are provided, a plurality of heater wires may be energized.

  In addition, the arrangement of the two or more heater wires is not particularly limited as long as the synthetic resin film can be sandwiched, but the synthetic resin film is fused in a tensioned state so that the seal portion does not wrinkle. Therefore, it is preferable to arrange in parallel with the fusion direction.

  In the case of impulse sealing, the energizing current, voltage and energizing time are temperatures at which the heater wire temporarily generates heat and can soften and fuse the synthetic resin film, and overheated. There is no particular limitation as long as it does not cause any trouble. The same applies to heat sealing. In either case, the heating condition of the heater wire is determined by the type and number of synthetic resin films used.

  In addition, after printing the barcode which inputted the information of the synthetic resin film beforehand on the synthetic resin film and reading the barcode by the reading device etc., the control means provided in the manufacturing device etc. is based on the information. By energizing only the selected heater wire, it is not necessary for the operator to change the setting of the heater wire that is energized for each synthetic resin film to be loaded. It can correspond to.

The receiving portion used in the present invention is not particularly limited in material and shape as long as it is disposed at a position facing the above-described heater wire and can sandwich the synthetic resin film. The same heater wire can be used.
Here, in order to further prevent problems caused by uneven thickness of the synthetic resin film and the receiving part, it is preferable to use an elastic body such as silicon rubber having good peelability and heat resistance.

In the present invention, the pressure for sandwiching the synthetic resin film needs to be sufficient to heat and fuse at least a plurality of synthetic resin films.
Therefore, the pressure for sandwiching the synthetic resin film is determined by the type and number of the synthetic resin films to be used, but is approximately the same pressure as when the conventional heater wire was set. Or, it is preferable to hold it with a slightly strong pressure.
The reason is that if there is such a pressure, even if the number of heater wires is increased, the sealing portion will not be sufficiently fused and the strength of the sealing portion can be ensured.

According to the manufacturing method and the manufacturing apparatus of the packaging bag according to the present invention, by energizing, two or more heater wires that fuse the end portions of a plurality of synthetic resin films to produce a seal portion, and the heater wires It is provided with receiving parts arranged so as to face each other, applying a clamping pressure to hold the synthetic resin film between the heater wire and the receiving part, energizing only any heater wire of the heater wires, energizing other heater wires By doing so, even when the synthetic resin film heated by an arbitrary heater wire is softened when energized, the sandwiching pressure can be received by the other heater wire and the receiving portion that are not energized. .
Accordingly, it is possible to prevent fusion that forms a thin portion in a state where the synthetic resin film sandwiched between the heater wire to be energized and the receiving portion is pushed in the thickness direction, and as a result, creation While maintaining the strength of the sealed portion, a thin portion where stress is concentrated is not formed at the boundary between the sealed portion and the synthetic resin film that is not fused, and the problem of edge breakage can be solved.

Moreover, according to the manufacturing method and manufacturing apparatus of the packaging bag which concerns on this invention, since the heater wire to supply with electricity can be selected, the sealing position of the packaging bag produced can also be changed suitably.
Therefore, even in the synthetic resin films for various packaging bags with slightly different intervals, the so-called printing pitch, where the product name is printed on the long synthetic resin film, the lengths of both ends of the seal portion for each type, that is, By changing the length of the ear of the bag, it is possible to manufacture the packaging bag by fusing the synthetic resin film at an appropriate sealing position corresponding to the internal volume of the packaging bag.

In particular, if the heater wire closest to the cut portion of the synthetic resin film is energized and the synthetic resin film is fused, the length of the ear can be shortened.
Since these ears have been wasted in the past, the present invention capable of shortening the length of the ear leads to a reduction in the waste of packaging materials, and resource saving which has been regarded as important in recent years From the viewpoint of the environment such as, it also has a useful effect.
Moreover, since the situation which used the synthetic resin film which can be used as a bag for the ear which saturates can be improved also for the industry which handles cereals, generation | occurrence | production of useless cost can be prevented.
In addition, since conventional packaging materials with a long print pitch can be used simply by selecting the heater wire, these conventional packaging materials that have a considerable amount of inventory can be used without being discarded. And waste of packaging material can be prevented.

  Moreover, according to the manufacturing method and manufacturing apparatus of the packaging bag which concerns on this invention, since the heater wire to energize can be selected by reading the barcode printed on the synthetic resin film, the synthetic resin loaded It is not necessary for the operator to change the setting of the heater wire to be energized for each film, and it is possible to quickly respond to various types of synthetic resin films including those having different printing pitches.

The present invention will be described in detail with reference to the drawings showing embodiments thereof. The embodiment described below is merely an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a side view showing a packaging bag manufacturing method (lower sealing step) and a film cutting step according to the first embodiment of the present invention, and FIG. 2 shows a packaging bag according to the second embodiment of the present invention. It is a side view which shows a manufacturing method (upper sealing process).
In FIG. 1, 1 is a synthetic resin film, 2 is a heater wire, 3 is a receiving portion, 4 is a cutting blade, 5 is a film pressing mechanism, 6 is an insulating tape, 7 is a Teflon (registered trademark) sheet, 8 is a lower seal, 9 is a lower ear, 10 is a packaging bag. In FIG. 2, 2 is a heater wire, 3 is a receiving portion, 6 is an insulating tape, 7 is a Teflon (registered trademark) sheet, 10 is a packaging bag, and 11 is an upper seal. , 12 is an upper ear, and 13 is a package filled with grains and the like.

FIG. 3 is a side view showing a packaging bag manufacturing apparatus using the packaging bag manufacturing method according to the present invention, and FIG. 4 is a block diagram showing the flow of heater wire control in the lower sealing process and the upper sealing process. FIG.
In FIG. 3, 8 is a lower seal, 9 is a lower ear, 10 is a packaging bag, 14 is a manufacturing device, 15 is a lower sealing process, 16 is a film cutting process, 17 is a holding process, 18 is an upper sealing process, 19 is Roller, 20 is a film feeding mechanism, 21 is a rail, 22 is a hopper, 23 is a hopper outlet that can be vertically expanded and contracted, 24 is a type information reading means, in FIG. 4, 24 is a type information reading means, and 25 is a control management Means 26, film information output means, 27 film information storage means, and 28 heater wire control means.

  Hereinafter, the operation of the packaging bag manufacturing method and the manufacturing apparatus configured as described above will be described along the manufacturing process of the packaging bag.

  First, as shown in FIG. 3, the long cylindrical synthetic resin film 1 wound in a roll shape loaded in the manufacturing apparatus 14 passes through the type information reading means 24 using a roller 19 or the like, and is in a lower sealing step 15. Sent to.

Here, the type information reading means 24 reads the type information for each synthetic resin film 1 from a bar code (not shown) printed on the synthetic resin film 1 as shown in FIG. Are sent to the film information output means 26 in the control management means 25 for managing all the operations.
In the film information output means 26, information on the heater wire to be energized determined for each synthetic resin film 1 corresponding to the type information of the sent synthetic resin film 1 is output from the film information storage means 27, and the heater line control means Send to 28.
The heater wire control means 28 energizes predetermined heater wires (here, 2a and 2e) in the heater wire 2 in the lower sealing step 15 and the upper sealing step 18 based on the sent film information.

Next, in the lower sealing step 15 and the film cutting step 16, based on the control of the heater line control means 28, as shown in FIG. The lower seal 8 is produced by energizing only 2a), and the lower part of the lower seal 8 is cut in a direction perpendicular to the longitudinal direction of the synthetic resin film 1.
Specifically, as shown in FIG. 1A, the synthetic resin film 1 sent to the lower sealing step 15 is sandwiched and loaded by the heater wire 2 and the receiving portion 3 in FIG. 1B. The lower seal 8 is manufactured by energizing only the heater wire (in this case, 2a) to be the lower seal 8 of the synthetic resin film 1. Then, substantially simultaneously with the production of the lower seal 8, the lower portion of the lower seal 8 is cut by the cutting blade 4 positioned below the lower seal 8. The lower ear 8 extends from the lower seal 8 to the end of the cut synthetic resin film 1. In the present embodiment, a pressing mechanism 5 for the synthetic resin film 1 is provided below the cutting blade 4 so that the synthetic resin film 1 can be easily cut by the cutting blade 4.

Here, FIG.1 (b-1) is an enlarged view which shows the state by which the synthetic resin film 1 is clamped with the heater wire 2 and the receiving part 3 before electricity supply in FIG.1 (b), FIG. 1B-2 is an enlarged view showing a state where the heater wire 2a is energized in FIG. 1B and the synthetic resin film 1 is softened and fused.
As shown in FIG. 1 (b-2), since the heater wires 2b and 2c other than the heater wire 2a are not energized, the distance r between the heater wire 2 and the receiving portion 3 in the state where the synthetic resin film 1 is sandwiched is Even when the heater wire 2a is energized and the synthetic resin film 1 is softened, it hardly changes.
Therefore, since the synthetic resin film 1 is fused without being pushed in the thickness direction as the seal portion becomes thinner by the heater wire 2a, the so-called edge portion can be prevented from being formed.
Here, depending on the form of the packaging bag to be manufactured, the heater wire to be energized may be any one of 2a, 2b and 2c, or energize any two of 2a, 2b and 2c, It is also possible not to energize the remaining one. In this embodiment, the number of heater wires is three, but the number of heater wires may be further increased according to the synthetic resin film to be used.

FIG. 5 is a view showing a conventional lower sealing step and a film cutting step. Reference numeral 106 denotes an insulating tape, which is a 107 Teflon (registered product) sheet.
Here, in the conventional lower sealing step 101, there is only one heater wire 102, and the synthetic resin film 1 is sandwiched and the synthetic resin film 1 is fused only by the one heater wire 102 and the receiving portion 103. Yes.
Therefore, as shown in FIG. 5B-2, when the heater wire 102 is energized and the synthetic resin film 1 is softened, the synthetic resin film 1 is melted in a state where the heater wire 102 is pushed in the thickness direction. Will be worn. As a result, the lower seal 108 of the synthetic resin film 1 becomes thin, and an edge portion 109 where stress is concentrated is formed at the boundary portion.

Next, the synthetic resin film 1 on which the lower seal 8 has been manufactured and cut has a predetermined dimension based on the dimension information output by the film information output means 26 in the film feeding mechanism 20 as shown in FIG. Only sent down.
The sent synthetic resin film 1 is subjected to the lower sealing step 15 and the film cutting step 16 of the next packaging bag 10. As a result, the packaging bag 10 in which the lower seal 8 is formed only in the lower portion and the seal portion is not formed in the upper portion is produced.

Next, in the holding step 17, a filling step (not shown) for holding and holding the upper end portion of the packaging bag 10 created in the above step at both end positions in the short direction, and filling the packaging bag 10 with the contents, And move to the upper sealing step 18.
FIG. 6 is a plan view showing a holding process for moving the packaging bag to the filling process and the upper sealing process, and FIG. 7 is a side view showing the holding process.
Here, the holding step 17 is a pair of clamps 29 that can be opened and closed as shown in FIGS. 6A and 6B, and holds the packaging bag 10 as shown in FIG. Further, the holding step 17 can move in the lateral direction on the rail 21 in a state where both ends of the packaging bag 10 in the short direction are sandwiched.
In the present embodiment, since the packaging bag 10 is held in an upright state, the holding step 17 includes a holding position during movement to the filling step (not shown) and the upper sealing step 18. A lead member 30 for guiding the packaging bag 10 in the longitudinal direction is provided so that the portion of the packaging bag 10 positioned above is not bent. Due to the presence of the lead member 30, even when the packaging bag 10 is protruded by about 50 mm above the lead member 30, the portion can be moved between the steps without being bent.

  In the filling process, it is necessary to open the packaging bag 10 in order to fill the bag with the contents. Therefore, the holding process 17 is provided with a slide mechanism 31 that moves the clamp 29 in the inner direction of the packaging bag 10 in order to make play when the packaging bag 10 is opened.

Next, the packaging bag 10 is moved to a filling step (not shown) and an upper sealing step 18 as shown in FIG. FIG. 8 is a schematic diagram showing a state when the packaging bag is moved to the filling process and the upper sealing process.
In the filling step, the upper end portion of the packaging bag 10 on the side where the upper seal 11 is not yet formed is opened, and the hopper outlet 23 is extended downward from the opening end portion to a place where the object to be filled does not scatter. Fill the contents. About the means to open the upper end part of the packaging bag 10, it can carry out by providing the suction cup (not shown) etc. which suck | inhale and open the packaging bag 10 as above-mentioned.

  Since the packaging bag 10 does not move when the filling process and the upper sealing process 18 are performed, the clamp with the lead member 30 used in the holding process 17 is performed when the above process is performed. 29, the upper end of the packaging bag 10, i.e., the portion at the cutting portion, is further changed by moving it to a clamp (not shown) that does not have a guide that is held slightly below the upper end of the packaging bag 10. It can also be sealed.

Finally, in the upper sealing step 18, the filling of the contents is completed by the filling step, and the upper end of the packaging bag 10 is sealed after the hopper outlet 23 is contracted upward.
As shown in FIG. 2, in the upper sealing step 18, as in the lower sealing step 15, based on the control of the heater line control means 28, a heater wire (in this case, 2e) that becomes the upper seal 11 of the loaded packaging bag 10. ) Only to energize and produce the upper seal 11, thereby completing the package 13 filled with the grain or the like on which the upper ears 12 are formed.

Here, FIG. 2 (b-1) is a schematic diagram showing a state in which the packaging bag 10 is sandwiched between the heater wire 2 and the receiving portion 3 before being energized in FIG. 2 (b). 2 (b-2) is a schematic diagram showing a state where the heater wire 2e is energized in FIG. 2 (b) and the packaging bag 10 is softened.
As shown in FIG. 2 (b-2), since the heater wires 2d other than the heater wire 2e are not energized, the distance r between the heater wire 2 and the receiving portion 3 in the state where the packaging bag 10 is sandwiched is the heater wire. Even when the current is applied to 2e and the packaging bag 10 is softened, it hardly changes.
Therefore, since the synthetic resin film 1 is fused without being pushed in the thickness direction by the heater wire 2e, so-called edge portions can be prevented from being formed.
Here, depending on the form of the packaging bag to be manufactured, the heater wire to be energized can be 2d, and the heater wire not to be energized can be 2e. In this embodiment, the number of heater wires is two, but the number of heater wires may be further increased according to the synthetic resin film to be used.

Next, the strength of the seal portion was compared between the packaging bag produced by the above method and the packaging bag produced by the conventional method.
First, using a nichrome heater wire with a thickness of 0.15 mm, a width of 2 mm, and a resistance of 2 Ω, three heater wires were used, and only one of them was energized. A packaging bag was prepared by removing a single heater wire and energizing only one heater wire. The synthetic resin film was made of a polyethylene film having a thickness of 0.06 mm, the energizing voltage was set to 35 V, and the energizing time was changed.
Then, a strip-shaped test sample having a width of 35 mm and a length of 40 mm was cut out and subjected to a tensile test so that the seal portion went straight from the produced packaging bag to the center in the longitudinal direction. The test conditions were a distance between chucks: 10 mm and a tensile speed: 80 mm / sec, and the numerical value at which the seal part was broken was measured.
FIG. 9 is a diagram showing the results of a tensile strength test of the seal portion of the packaging bag manufactured by the manufacturing method according to the present invention.
From the results of FIG. 9, even when the energization time is changed, the sealing part of the packaging bag manufactured by the manufacturing method in the present invention shows a higher tensile strength than the conventional sealing part, so the present invention is It was found that it was possible to prevent the formation of thin-walled parts that would cause edge breaks.

  The present invention can be used for manufacturing a packaging bag for packaging granular materials such as grains.

It is a side view which shows the manufacturing method (lower sealing process) and film cutting process of the packaging bag which concern on the 1st Embodiment of this invention. It is a side view which shows the manufacturing method (upper sealing process) of the packaging bag which concerns on the 2nd Embodiment of this invention. It is a side view which shows the manufacturing apparatus of the packaging bag using the manufacturing method of the packaging bag which concerns on this invention. It is a block diagram which shows the flow of control of the heater line in a lower sealing process and an upper sealing process. It is a figure which shows the conventional lower sealing process and a film cutting process. It is a top view which shows the holding process for moving a packaging bag to a filling process and an upper sealing process. It is a side view which shows a holding process. It is a schematic diagram which shows the state at the time of moving a packaging bag to a filling process and an upper sealing process. It is the figure which showed the result of the tensile strength test of the seal part of the packaging bag manufactured with the manufacturing method in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Synthetic resin film 2 Heater wire 3 Receiving part 4 Cutting blade 5 Film pressing mechanism 6 Insulating tape 7 Teflon (registered trademark) sheet 8 Lower seal 9 Lower ear 10 Packaging bag 11 Upper seal 12 Upper ear 13 Packaging 14 Production apparatus 15 Lower sealing process 16 Film cutting process 17 Holding process 18 Upper sealing process 19 Roller 20 Film feeding mechanism 21 Rail 22 Hopper 23 Hopper outlet 24 Type information reading means 25 Control management means 26 Film information output means 27 Film information storage means 28 Heater wire Control means 29 Clamp 30 Lead member 31 Slide mechanism

Claims (2)

In a method for manufacturing a packaging bag of granular materials such as rice and grains, two or more heater wires for producing a seal portion by fusing ends of a plurality of synthetic resin films by energization, and the heater wires A receiving portion disposed so as to be opposed to each other, applying a holding pressure to hold the synthetic resin film between the heater wire and the receiving portion, energizing only any heater wire of the heater wires, By not energizing the heater wires, even when the synthetic resin film heated by the arbitrary heater wires is softened when energized, the holding pressure is received by the other heater wires not energized and the receiving portion. Therefore, the synthetic resin film is fused without the energized heater wire being pushed in the thickness direction of the synthetic resin film, and the synthetic resin film is not fused with the seal portion. US to prevent the thin portion where the stress is concentrated at the boundary between Lum is formed, the manufacturing method of the packaging bag of granules, such as cereals. 2. The packing bag for granular materials such as grain according to claim 1, wherein a heater wire to be energized among the two or more heater wires is selected by a barcode printed on the synthetic resin film. Production method.

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