JP7701706B2 - Bag making method, bag making equipment - Google Patents

Description

The present invention relates to a bag making method and a bag making device.

Patent document 1 discloses a bag-making method that includes a process of heat-sealing a film unwound from a roll to form the film into a bag shape.

JP 2015-24506 A

The contents of the bags produced by the method of Patent Document 1 tend to adhere to the inner surface of the bag. For this reason, a bag-making method that can prevent the contents from adhering is desired.

The present invention was made in consideration of these circumstances, and provides a bag making method that can prevent the contents from sticking.

According to the present invention, there is provided a bag making method including a coating step, a drying step, and a heat sealing step, in which in the coating step, a dispersion liquid is applied to a film unwound from an original roll, the dispersion liquid containing a dispersion medium and water-repellent particles dispersed in the dispersion medium, in the drying step, the dispersion medium is evaporated to dry the film, and in the heat sealing step, the film is heat-sealed after the drying step to form the film into a bag shape.

In the present invention, a dispersion liquid containing water-repellent particles is applied to a film, the film is dried, and then heat-sealed to form a bag. The water-repellent particles adhere to the inner surface of the bag produced in this manner, preventing the contents from adhering to the surface.

Various embodiments of the present invention will be described below. The embodiments described below can be combined with each other.
Preferably, in the bag-making method described above, in the coating step, the dispersion is coated on the film in a state in which tension is applied to the film.
Preferably, in the bag-making method described above, in the heat-sealing step, the heat-sealing is performed intermittently, and in the coating step, tension is constantly applied to the film by a tension roller and a feed roller provided before and after a position where the dispersion is applied.
Preferably, in the above-described bag-making method, the coating is performed by spraying.
Preferably, in the bag making method described above, the heat sealing includes a horizontal seal in a direction perpendicular to the longitudinal direction of the film, and in the application step, the dispersion is not applied to the film in the area where the horizontal seal is performed.
Preferably, in the bag making method described above, the heat sealing includes a vertical seal in a direction along the longitudinal direction of the film, and in the application step, the dispersion is not applied to the film in the area where the vertical seal is to be performed.
Preferably, in the bag making method described above, in the coating process, the dispersion liquid is applied to one side of the film, and in the drying process, the film is guided via a guide roller, and the guide roller is positioned so as not to contact the one side.
Preferably, in the bag-making method described above, the coating is carried out by passing the film through an immersion tank containing the dispersion liquid.
Preferably, in the above-described bag-making method, the drying step is carried out while the film is being pulled up from the immersion tank.
Preferably, in the above-described bag-making method, the dispersion liquid contains resin beads dispersed in the dispersion medium.
Preferably, in the bag making method described above, the coating step includes first and second coating steps, in which a first dispersion is applied to the film in the first coating step, and a second dispersion is applied to the film in the second coating step, the first dispersion includes a first dispersion medium and the resin beads dispersed in the first dispersion medium, the second dispersion includes a second dispersion medium and the water-repellent particles dispersed in the second dispersion medium, and the first and second coating steps are separate steps.
Preferably, in the above-described bag-making method, the second coating step is carried out after the first coating step.
Preferably, in the bag-making method described above, the drying step is performed in the same drying section after each of the first and second coating steps.
Preferably, in the bag-making method described above, the film has an uneven shape prior to the coating step.
Preferably, the bag making apparatus is provided with a coating section, a drying section, and a heat sealing section, in which the coating section applies a dispersion liquid to a film unwound from an original roll, the dispersion liquid including a dispersion medium and water-repellent particles dispersed in the dispersion medium, the drying section evaporates the dispersion medium to dry the film, and the heat sealing section heat-seals the film after the drying process to form the film into a bag shape.

1 is a schematic front view showing a configuration of a bag making apparatus 1 according to a first embodiment of the present invention. 2A is a plan view of the vicinity of the spray mechanism 7 and the drying chamber 8 in FIG. 1 (the drying chamber 8 is a cross-sectional view), FIG. 2B is a left side view of FIG. 2A, and FIG. 2C is a cross-sectional view taken along line AA in FIG. 2A. 13 is a plan view of the vicinity of a drying chamber 8 of a bag making apparatus 1 according to a second embodiment of the present invention (the drying chamber 8 is a cross-sectional view). FIG. 13 is a schematic front view showing the configuration of the spray mechanisms 7a, 7b and the drying chamber 8 of the bag making apparatus 1 according to the third embodiment of the present invention. FIG. 13 is a schematic front view showing the configuration in the vicinity of an immersion tank 17 of a bag making apparatus 1 according to a fourth embodiment of the present invention. FIG.

The following describes the embodiments of the present invention. The various features shown in the embodiments below can be combined with each other. In addition, each feature can be an invention independently.

1 and 2, a bag making apparatus 1 according to a first embodiment of the present invention will be described. The bag making apparatus 1 includes an original roll 12, guide rollers 3a-3k, a tension roller 4, feed rollers 5a-5c, a dancer roller 6, a spray mechanism (an example of a "coating section") 7, a drying chamber (an example of a "drying section") 8, a cooling chamber 9, a film processing mechanism 10, and a heat sealing section 11. The bag making method according to one embodiment of the present invention can be carried out by the bag making apparatus 1.

<Original roll 12>
The original web roll 12 is a roll around which the film 2 is wound. The force of the feed roller 5a to feed out the film 2 causes the film 2 to be unwound from the original web roll 12. The film 2 may be fed out by rotating a shaft 12a on which the original web roll 12 is attached.

<Film 2>
The film 2 may be any film having a heat seal layer and capable of heat welding between films. Examples of the film 2 include a single-layer film made of a thermoplastic resin having heat sealability, a sheet, and a multilayer film in which a thermoplastic resin having heat sealability is laminated with another thermoplastic resin. Examples of materials having good heat sealability include known low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, olefin resins such as olefin resins graft-modified with ethylenically unsaturated carboxylic acid or its anhydride, polyamide or copolyamide resins having a relatively low melting point or low softening point, polyester or copolyester resins, and polycarbonate resins. Examples of other plastic materials to be laminated include various barrier films. When using a laminated film, it is preferable to heat-weld the thermoplastic resin layers having good heat sealability, such as resins having a low melting point, on the inner side.

<Guide rollers 3a to 3c, tension roller 4>
A guide roller 3a, a tension roller 4, and guide rollers 3b and 3c are disposed in this order between the original roll 12 and the feed roller 5a. The guide rollers are provided to suppress meandering, wrinkles, slackness, etc. of the film 2, and the number and locations of the guide rollers are set appropriately.

The tension roller 4 is configured to apply tension to the film 2. Specifically, the tension roller 4 is constantly biased toward the film 2 by its own weight or a biasing means such as a spring.

<Spray mechanism 7>
The spray mechanism 7 is disposed between the tension roller 4 and the feed roller 5a. The tension roller 4 and the feed roller 5a provided before and after the spray mechanism 7 constantly apply tension to the film 2, so that the spray mechanism 7 sprays (an example of "application") the dispersion liquid 13 (described in detail below) onto the film 2 while tension is being applied to the film 2 (application step). If the dispersion liquid 13 is applied to the film 2 while it is in a slack state, there is a risk that the dispersion liquid 13 will be applied unevenly. However, in this embodiment, the dispersion liquid 13 is applied to the film 2 while tension is being applied to the film 2, so that the dispersion liquid 13 can be applied evenly.

The area to which the spray mechanism 7 applies the dispersion liquid 13 is not particularly limited, and the dispersion liquid 13 may be applied to the entire surface of the film 2 or to a partial area. If the dispersion liquid 13 is applied to the area where vertical or horizontal sealing is performed, there is a risk of reducing the seal strength, so it is preferable not to apply the dispersion liquid 13 to the area where vertical sealing is performed or the area where horizontal sealing is performed. A vertical seal is a heat seal in a direction along the longitudinal direction of the film, and a horizontal seal is a heat seal in a direction perpendicular to the longitudinal direction of the film.

In this embodiment, as shown in FIG. 2B, the areas near both ends of the film 2 are covered with covers 14 to prevent the dispersion liquid 13 from being applied to the area where the vertical seal is to be made. In addition, the film 2 is moved in the longitudinal direction with the spray of the dispersion liquid stopped, to prevent the dispersion liquid 13 from being applied to the area where the horizontal seal is to be made.

As a result, after passing through the spray mechanism 7, one side of the film 2 is formed with a coated area 2a where the dispersion liquid 13 is coated, a non-coated area 2b including an area where vertical sealing is performed, and a non-coated area 2c including an area where horizontal sealing is performed. The other side of the film 2 is not coated with the dispersion liquid 13, and the entire surface is a non-coated area.

<Dispersion liquid 13>
The dispersion liquid 13 contains a dispersion medium, resin beads, and water-repellent particles. After the dispersion liquid 13 containing such components is applied, the dispersion medium is evaporated in a drying process, whereby an uneven shape is formed on the surface of the film 2 by the resin beads, and a structure is obtained in which the water-repellent particles are attached to the uneven surface. When such a structure is formed on the inner surface of the bag to be manufactured, the physical action of the uneven shape and the chemical action of the water-repellent particles make it difficult for the contents to adhere to the surface.

The dispersion liquid 13 contains a dispersion medium, resin beads, and water-repellent particles. The dispersion medium may be any liquid capable of dispersing the resin beads and water-repellent particles, such as water or alcohol (e.g., ethanol).

Resin Beads By adhering resin beads to the film 2, it is possible to impart superior abrasion resistance and the like to the packaging material.

As resin beads, beads of resin components (or organic polymer components) such as acrylic resin, urethane resin, melamine resin, amino resin, epoxy resin, polyethylene resin, polystyrene resin, polypropylene resin, polyester resin, cellulose resin, vinyl chloride resin, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, polyacrylonitrile, polybutyl methacrylate, polyacrylic acid ester, polymethyl methacrylate, polyamide, etc. can be suitably used.

The shape of the resin beads is not limited, and may be, for example, spherical, spheroidal, irregular, teardrop-shaped, flat, hollow, porous, etc.

The average particle size of the resin beads is not particularly limited and can be set appropriately within the range of, for example, 1 to 50 μm, preferably 1 to 30 μm. However, since the gaps between the resin beads are actively utilized, it is preferable that the average particle size of the resin beads is larger than the average primary particle size of the water-repellent particles.

The melting point of the resin beads is preferably lower than the melting point of the heat seal layer, and more preferably 160°C or lower. By using resin beads with such a melting point, the adhesion of the resin beads to the heat seal layer is improved, and the abrasion resistance and non-adhesiveness can be more effectively maintained. From this perspective, the material of the resin beads is preferably a polyolefin resin, and at least one of polyethylene resin, polypropylene resin, polybutene resin, etc. can be suitably used.

Even if the melting point of the resin beads is higher than that of the heat seal layer, if a heat seal layer with a low melting point is used, the adhesion between the resin beads and the heat seal layer will be good, and the abrasion resistance and non-adhesiveness can be effectively maintained as described above. In other words, by welding a part of the resin beads to a part of the surface of the heat seal layer, the resin beads are firmly fixed onto the heat seal, and the synergistic effect with the water-repellent particles attached to the gaps and surface allows the abrasion resistance and non-adhesiveness to be more effectively maintained.

The average particle size of the resin beads can be measured using a laser diffraction particle size distribution analyzer. If it is difficult to measure using a laser diffraction particle size distribution analyzer, the beads can be observed (or photographed) using a microscope, for example a scanning electron microscope, and the diameter can be taken as the diameter if the particle shape is spherical, or the average of the longest and shortest diameters if the particle shape is non-spherical. The average diameter can be taken as the average of the diameters of 20 particles randomly selected from observation using a scanning electron microscope, etc.

The amount of resin beads attached to the packaging material of the present invention can be appropriately changed depending on the type and average particle size of the resin beads, but is usually preferably about 1.0 to 10.0 g/ ^m2 , and more preferably about 2.0 to 4.0 g/ ^m2 .

Water-repellent particles The water-repellent particles are not particularly limited as long as they are hydrophobic, and specifically, hydrophobic oxide particles can be used. They may also be made hydrophobic by surface treatment. For example, hydrophilic oxide particles can be surface-treated with a silane coupling agent or the like to make the surface hydrophobic.

As the oxide fine particles, more specifically, at least one of silica (silicon dioxide), alumina, titania, etc. can be preferably used. Among these, hydrophobic silica fine particles can be preferably used. In particular, hydrophobic silica fine particles having trimethylsilyl groups on the surface are preferable in terms of obtaining superior non-adhesive properties. Examples of corresponding commercially available products include the above-mentioned "AEROSIL R812" and "AEROSIL R812S" (both manufactured by Evonik Degussa).

The amount of water-repellent particles (weight after drying) attached to the surface of the packaging material is not limited, but is usually preferably 0.01 to 10 g/m ² , more preferably 0.2 to 1.5 g/m ² , and most preferably 0.2 to 1 g/m ^2. By setting it within the above range, better non-adhesiveness can be obtained for a long period of time, and it is more advantageous in terms of suppressing the water-repellent particles from falling off, costs, etc. The water-repellent particles attached to the surface of the packaging material preferably form a porous layer having a three-dimensional mesh structure, and the thickness thereof is preferably about 0.1 to 5 μm, and more preferably about 0.2 to 2.5 μm. By attaching in such a porous layer state, the layer can contain a lot of air, and better non-adhesiveness can be exhibited.

The primary particle average diameter of the water-repellent particles is preferably about 3 nm to 20 μm, more preferably 3 to 100 nm, and most preferably 5 to 50 nm. In the present invention, the primary particle average diameter can be measured using a scanning electron microscope (SEM, FE-SEM). If the resolution of the scanning electron microscope is low, it may be measured using another electron microscope such as a transmission electron microscope in combination. Specifically, if the particle shape is spherical, the diameter is considered to be the diameter, and if the particle shape is non-spherical, the average of the longest and shortest diameters is considered to be the diameter, and the average of the diameters of 20 particles randomly selected by observation using a scanning electron microscope or the like is taken to be the primary particle average diameter.

<Feed roller 5a>
The feed rollers 5a have a function of moving the film 2 in the longitudinal direction by being driven to rotate while holding the film 2 between the pair of rollers. The feed rollers 5a adjust the feed speed so that the passing speed of the film 2 in the coating process is constant. This enables the dispersion liquid 13 to be uniformly applied.

In this embodiment, as shown in FIG. 2C, the feed roller 5a includes a left feed roller 5a1 and a right feed roller 5a2. The left feed roller 5a1 is composed of a pair of rollers 5a1u and 5a1b. The right feed roller 5a2 is composed of a pair of rollers 5a2u and 5a2b. The left feed roller 5a1 and the right feed roller 5a2 are each configured to grip the non-coated area 2b. With this configuration, the feed roller 5a does not contact the coated area 2a, so the dispersion liquid 13 is prevented from adhering to the feed roller 5a. The rollers 5a1b and 5a2b may be connected to form a single roller. The lower surface of the film 2 is entirely a non-coated area, so even with this configuration, the dispersion liquid 13 does not adhere to the rollers.

<Drying chamber 8>
The temperature inside the drying chamber 8 is high, and the film 2 is passed through the drying chamber 8 to evaporate the dispersion medium and dry the film (drying step). This allows the resin beads and water-repellent particles to adhere to the film 2. The drying step may be performed without using the drying chamber 8, for example, by irradiating the film 2 with heat rays using a heater to heat the film 2.

The drying temperature may be any temperature at which the dispersion medium can evaporate, but is preferably a temperature equal to or higher than the melting point of the resin beads. In this case, the resin beads are firmly fused to the film 2. The drying temperature is preferably set at a temperature at which the heat seal layer substantially maintains its original shape and the resin beads are fused to the surface of the heat seal layer. More specifically, it is preferable to heat to a temperature below the melting point of the heat seal layer and equal to or higher than the melting point of the resin beads. In particular, a temperature of 130 to 200°C is preferable. The drying temperature is preferably, for example, 130 to 200°C.

In the drying chamber 8, the film 2 is guided along the wall surface of the drying chamber 8 via guide rollers 3d to 3f. By guiding the film 2 along the wall surface, the time that the film 2 stays in the drying chamber 8 is longer, making it easier for drying to proceed sufficiently. The guide rollers 3d to 3f are positioned so as not to come into contact with the surface of the film 2 on which the dispersion liquid 13 is applied (in other words, they are positioned so as to come into contact with the surface opposite to the surface on which the coating area 2a is located). This prevents the dispersion liquid 13 from adhering to the guide rollers 3d to 3f.

<Cooling chamber 9>
The film 2 from the drying chamber 8 is guided by guide rollers 3g and 3h to the cooling chamber 9. In the cooling chamber 9, the film 2 which has become hot in the drying chamber 8 is cooled. In the cooling chamber 9, it is sufficient to cool the film 2 to a degree that does not cause any problems in the subsequent steps. The cooling chamber 9 can be omitted if it is not necessary.

<Feed roller 5b>
The film 2 from the cooling chamber 9 is guided to the feed roller 5b by the guide roller 3i. The feed roller 5b has a function of moving the film 2 in the longitudinal direction by being rotated while the pair of rollers grip the film 2. By providing the feed roller 5b downstream of the drying chamber 8, it becomes easy to adjust the drying conditions. The feed roller 5b continuously feeds the film 2 at a constant speed.

One of the feed rollers 5a and 5b can be omitted. If one of them is omitted, it is preferable to omit the feed roller 5a.

When the film 2 comes into contact with the feed roller 5b, the film 2 is already dry, so the feed roller 5b may be structured to come into contact with the coating area 2a. In this case, the feed roller 5b can be in contact with the entire width of the film 2 to feed the film 2, so that the film 2 can be fed stably.

<Dancer roller 6, film processing mechanism 10, heat seal unit 11, feed roller 5c>
Between the feed roller 5b and the feed roller 5c, a dancer roller 6 and guide rollers 3j and 3k are provided. Between the guide rollers 3j and 3k, a film processing mechanism 10 and a heat seal unit 11 are provided.

The film processing mechanism 10 processes the film 2 so that the desired bag can be obtained by heat sealing. Processing here means folding, cutting, etc. of the film. The film processing mechanism 10 also layers the film 2 so that the area to be heat sealed is multiple layers, forming a laminated film 2d. The type of bag is not limited, and may be any of two-sided bags, three-sided bags, three-sided bags with zippers, palm-shaped bags, gusset bags, bottom gusset bags, stand bags, stand zipper bags, four-column flat-bottom gusset bags, side seal bags, bottom seal bags, etc.

In the heat sealing section 11, the laminated film 2d is heat sealed to form a bag-like bag-made film 2e (heat sealing process). Heat sealing can be performed by pressing a sealing bar heated to a temperature at which the heat seal layer can melt against the film 2 that is stacked in multiple layers. The heat sealing can include horizontal sealing perpendicular to the longitudinal direction of the film 2 and vertical sealing along the longitudinal direction of the film 2. Either the horizontal sealing or the vertical sealing can be performed first.

The heat sealing unit 11 may include a filling unit that fills the contents. In this case, for example, a vertical bag making and filling machine is preferable, and after heat sealing is performed to form a bag that is only open at the top, the contents are filled, and then the top of the contents is heat sealed to seal the contents.

In this embodiment, we are assuming the production of refill pouches and pouches for commercial use, rather than small bags (less than 100 mL). Capacity may be 250 ml, 300 ml, 500 ml, 1 L, 2 L, 5 L, 10 L, 15 L, 20 L, etc. Therefore, in order to increase the seal strength, intermittent sealing is performed instead of continuous sealing.

In intermittent heat sealing, the seal bar is pressed against the laminated film 2d while the laminated film 2d is stopped. This allows the seal bar to be pressed for a period of time sufficient to obtain the required strength, thereby increasing the seal strength.

In intermittent heat sealing, the process of feeding the laminated film 2d a predetermined length and the heat sealing process are repeated to produce a bagged film 2e.

When filling the contents, the process of feeding the laminated film 2d a predetermined length, the first heat sealing process, the content filling process, and the second heat sealing process are repeated. In the first heat sealing process, heat sealing is performed so that a bag that is only open at the top is formed, and in the second heat sealing process, the top of the contents is heat sealed to seal the contents.

The feed roller 5c has the function of moving the bag-made film 2e and the laminated film 2d and film 2 connected to it along the longitudinal direction by being rotated while the pair of rollers grip the bag-made film 2e. The feed roller 5b feeds the film 2 at a constant speed, and the feed roller 5c operates intermittently to feed the bag-made film 2e in accordance with the sealing time and filling time.

While feed roller 5c is stopped, feed roller 5b continues to operate. At this time, to prevent the film 2 from slackening, dancer roller 6 is driven to move between positions 6a and 6b. Specifically, immediately after feed roller 5c stops, dancer roller 6 is positioned at position 6b, and then dancer roller 6 gradually moves toward position 6a in sync with the feeding of film 2 by feed roller 5b. By moving dancer roller 6 in this manner, the occurrence of slack in the film 2 is suppressed.

When the feed roller 5c is driven to rotate, the dancer roller 6 moves to position 6b. This allows the feed roller 5c to feed the film 2 more smoothly. It is also possible to use a tension roller instead of the dancer roller 6, but the dancer roller 6 has the advantage that it can actively move from position 6a to position 6b, making it possible to feed the film more smoothly than a tension roller.

The bag-made film 2e is cut downstream of the feed roller 5c as necessary to form individual bags.

2. Second embodiment A second embodiment of the present invention will be described with reference to Fig. 3. This embodiment is similar to the first embodiment, and the main difference lies in the configuration of the drying chamber 8. The following description will focus on the differences.

In this embodiment, guide rollers 3u and 3v are arranged non-parallel within the drying chamber 8. The film 2 is guided so as to be wound in a spiral shape around the guide rollers 3u and 3v. With this configuration, the time that the film 2 stays within the drying chamber 8 can be extended, and the film 2 can be dried effectively.

3. Third embodiment A third embodiment of the present invention will be described with reference to Fig. 4. This embodiment is similar to the first embodiment, and the main difference lies in the configuration of the spray mechanism and the drying chamber. The following description will focus on the differences.

In this embodiment, first and second spray mechanisms (one example of an "applicator") 7a and 7b are provided. The first spray mechanism 7a applies the first dispersion liquid 13a (first application process). The second spray mechanism 7b applies the second dispersion liquid 13b (second application process). The first and second application processes are separate processes, and the second application process is performed after the first application process. The first dispersion liquid 13a contains a first dispersion medium and resin beads dispersed in the first dispersion medium. The second dispersion liquid 13b contains a second dispersion medium and water-repellent particles dispersed in the second dispersion medium. The first and second dispersion media may be the same or different. The dispersion medium, resin beads, and water-repellent particles are as described in the first embodiment.

The film 2 coated with the first dispersion liquid 13a in the first coating step is introduced into the drying chamber 8 and dried. In the second coating step, the film 2 removed from the drying chamber 8 is coated with the second dispersion liquid 13b, and this film 2 is introduced back into the drying chamber 8 and dried. Thus, in this embodiment, the drying after the first coating step and the drying after the second coating step are carried out in the same drying chamber 8. This allows equipment costs to be reduced.

In addition, the resin beads contained in the first dispersion liquid 13a are subjected to two drying processes, which makes it easier for the resin beads to be fused to the film 2.

The film 2 is guided by guide rollers 3b to 3f and 3l to 3p. The arrangement and number of the guide rollers can be changed as appropriate.

4. Fourth embodiment A fourth embodiment of the present invention will be described with reference to Fig. 5. This embodiment is similar to the first embodiment, and the main difference is the configuration of the application unit. The following description will focus on the differences.

The bag making device 1 of this embodiment is equipped with an immersion tank (an example of an "applying section") 17. The immersion tank 17 contains the same dispersion liquid 13 as in the first embodiment, and the film 2 can be applied with the dispersion liquid 13 by passing the film 2 through the immersion tank 17.

In the method of this embodiment, the dispersion liquid 13 is applied to the entire surface of both sides of the film 2, so the rollers cannot be positioned so that they do not come into contact with the applied surfaces.

Therefore, in this embodiment, a feed roller 5f is disposed downstream of the drying chamber 8, and the feed roller 5f is configured to lift the film 2 from the immersion tank 17. The feed roller 5f comes into contact with the film 2 after the film 2 has dried, so the dispersion liquid 13 does not adhere to the feed roller 5f. The feed roller 5f lifts the film 2 at a constant speed, so that the dispersion liquid 13 is evenly applied to the film 2.

Feed rollers 5d and 5e are provided upstream of the immersion tank 17, and a guide roller 3s is provided between the feed rollers 5d and 5e. The functions of the feed rollers 5d to 5f are the same as those of the feed roller 5a.

The feed roller 5d pulls out the film 2 from the original roll 12 and slackens the film 2 between the feed roller 5d and the guide roller 3s. This makes it easy to adjust the feed speed of the film 2 at the feed roller 5e.

The feed roller 5e is preferably positioned so that the feed side of the film 2 is located above the immersion tank 17. In this case, the film 2 fed from the feed roller 5e smoothly enters the immersion tank 17.

It is preferable that the feed speed of the film 2 by the feed roller 5e is equal to or greater than the feed speed of the film 2 by the feed roller 5f, and it is even more preferable that the feed speeds of the film 2 by the feed rollers 5e and 5f are equal.

This embodiment can also be implemented in the following variations:

Modification 1
In the first modified example, the feed roller 5d is not provided, and the shaft 12a is driven to rotate to unwind the film 2 from the original roll 12. The film 2 is slackened between the original roll 12 and the guide roller 3s.

Modification 2
In the second modification, the feed roller 5d and the guide roller 3s are not provided, and the film 2 is rewound from the original roll 12 only by the feeding force of the feed roller 5e.

Modification 3
In the third modification, instead of the immersion tank 17, a mist chamber filled with the mist is prepared by turning the dispersion 13 into a mist, and the film 2 is passed through the mist chamber to cause the mist of the dispersion 13 to adhere to the film 2, thereby applying the dispersion 13 to the film 2. The mist chamber is preferably under positive pressure.

5. Fifth embodiment A fifth embodiment of the present invention will be described. This embodiment is similar to the first embodiment, and the main difference lies in the dispersion liquid 13 and the film 2. The following description will focus on the differences.

In this embodiment, the film 2 has an uneven shape before the coating process. For example, the uneven shape can be formed on the film 2 by forming the film 2 using a raw resin containing particles capable of forming an uneven shape. Such particles are preferably larger than the water-repellent particles and do not melt under the molding conditions when the film 2 is manufactured, and examples of such particles include inorganic particles such as silica.

When the film 2 has an uneven shape, the dispersion liquid 13 may contain a dispersion medium and water-repellent particles without resin beads. This is because the uneven shape is already formed in the film 2.

6. Others The coating method for coating the dispersion 13 is not limited to the above, and any known method such as roll coating, gravure coating, bar coating, doctor blade coating, comma coater, brush coating, etc. can be used. When coating the water-repellent particles on an uneven surface, spraying or immersion bath coating is preferable to roll coating, because it is easier to attach the water-repellent particles to the fine details of the recesses.

The contents include foods, beverages, medicines, cosmetics, chemicals, etc., such as jelly sweets, pudding, yogurt, liquid detergent, toothpaste, curry roux, syrup, Vaseline, mayonnaise, ketchup, sauce, dressing, oils and fats, butter, margarine, flower paste, chocolate, jam, liquid egg, cheese, facial cleansing cream, facial cleansing mousse, etc. The properties of the contents also vary, such as solids, semi-solids, liquids, viscous bodies, gel-like substances, etc. Furthermore, the contents may be oil-based, aqueous, or amphoteric. When the contents are oil-based, it is preferable to use water-repellent particles that are also oil-repellent. The contents may contain solid matter.

The specifications of the bag making device 1 can be set as appropriate, and the number and arrangement of the various components that make up the bag making device 1 can be set as appropriate.

The advantages of applying the dispersion liquid and drying the film in the bag making apparatus 1 include the following.
- Relatively inexpensive film is available.
There are no restrictions on film structure (layer structure, thickness, etc.).
・It is possible to manufacture both products with and without dispersion coating using a single roll of raw material. For example, when filling with contents, it is possible to select whether or not to coat the contents when changing the contents, eliminating the need to replace the raw material roll.

1: Bag making device 2: Film 2a: Coating area 2b: Non-coating area 2c: Non-coating area 2d: Laminated film 2e: Films 3a to 3v: Guide roller 4: Tension rollers 5a to 5f: Feed roller 6: Dancer roller 7: Spray mechanism 7a: First spray mechanism 7b: Second spray mechanism 8: Drying chamber 9: Cooling chamber 10: Film processing mechanism 11: Heat seal section 12: Raw roll 12a: Shaft 13: Dispersion liquid 13a: First dispersion liquid 13b: Second dispersion liquid 14: Cover 17: Immersion tank

Claims (14)

A bag making method comprising a coating step, a drying step, and a heat sealing step,
In the coating step, a dispersion liquid is applied to a film unwound from a raw roll around which a film having a heat seal layer is wound,
The dispersion liquid includes a dispersion medium and water-repellent particles dispersed in the dispersion medium,
In the drying step, the dispersion medium is evaporated to dry the film,
In the heat sealing step, after the drying step, the film is heat-sealed to form the film into a bag shape,
the film is not wound into a roll during the period from the drying step to the heat sealing step, and at the time when the film is heat sealed, the portion of the film to be heat sealed is connected to the original roll ;
The coating is carried out by passing the film through an immersion bath containing the dispersion;
The drying step is performed while the film is being pulled up from the dipping tank by a first feed roller;
the first feed roller is configured to move the film along the longitudinal direction by being rotationally driven with the film being gripped by a pair of rollers;
The first feed roller is disposed vertically above the immersion tank,
The drying step is carried out in a drying chamber disposed between a first feed roller and the immersion tank;
The film is in a slack state in the immersion tank,
A bag making method , wherein no roller that comes into contact with the film is provided between the dipping tank and the first feed roller . 2. The method of claim 1 ,
a second feed roller, a guide roller, and a third feed roller are provided in this order from the immersion tank on the upstream side of the immersion tank;
the second and third feed rollers are each configured to move the film along the longitudinal direction by being rotationally driven while holding the film between the pair of rollers;
The method wherein the film is in a slack state between the guide roller and a third feed roller. 3. The method of claim 2,
A third feed roller draws the film from the web roll. 4. The method according to claim 2 or 3,
A method wherein the rate at which the film is fed by the second feed roller is equal to or greater than the rate at which the film is fed by the first feed roller. 5. The method of claim 4,
The method wherein the feed rate of the film through the second feed roller is equal to the feed rate of the film through the first feed roller. The method according to any one of claims 2 to 5,
A second feed roller is positioned such that the feed side of the film is positioned vertically above the immersion tank. The method according to any one of claims 1 to 6,
The method, wherein in the coating step, the dispersion is coated over the entire surface of both sides of the film. The method according to any one of claims 1 to 7,
A method wherein a first feed roller contacts the film after it has dried. A method according to any one of claims 1 to 8, comprising:
A first feed roller pulls up the film at a constant speed. The bag making method according to any one of claims 1 to 9,
The dispersion liquid includes resin beads dispersed in the dispersion medium. The bag making method according to any one of claims 1 to 9,
The coating step includes a first coating step and a second coating step,
In the first coating step, a first dispersion is coated onto the film,
In the second coating step, a second dispersion is applied to the film,
The first dispersion includes a first dispersion medium and resin beads dispersed in the first dispersion medium;
the second dispersion liquid includes a second dispersion medium and the water-repellent particles dispersed in the second dispersion medium,
The bag making method, wherein the first and second coating steps are separate steps. The bag making method according to claim 11,
The bag making method, wherein the second coating step is performed after the first coating step. The bag making method according to claim 11 or 12,
The bag making method, wherein the drying step is performed in the same drying section after each of the first coating step and the second coating step. The bag making method according to any one of claims 1 to 11,
The bag-making method, wherein the film has an uneven shape prior to the coating step.