JP2023017616A - Bag opening device and bag opening method - Google Patents

Abstract

A bag-opening device and a bag-opening method are provided which are advantageous in opening a bag more reliably.
A bag opening device includes a bag support section, a gas blowing section, and a bag opening heating section. The bag support portion 22 supports the bag B. As shown in FIG. The gas blowing section blows gas onto the opening Bm of the bag B supported by the bag supporting section 22 to open the opening Bm. The bag opening heating unit 31 heats the opening Bm prior to blowing the gas onto the opening Bm.
[Selection drawing] Fig. 2B

Description

The present disclosure relates to a bag opening device and a bag opening method.

A device that opens the mouth of a bag by blowing gas onto the mouth is known (see Patent Document 1).

For example, while the bag is supported by the bag supporting portion, the opening of the bag is directed upward, and gas is blown from above the bag toward the opening, thereby forming the opening between the films (the front side film and the back side film) that form the opening. Gas can enter and the mouth can be opened wide.

JP 2020-37443 A

At the opening of the empty bag, the front side film and the back side film are in close contact with each other and may stick strongly to each other.

For example, depending on the capacity of the bag making machine that produces the bag, the properties of the film used for the bag (material, etc.), or the bag production environment and bag storage environment (such as humidity, temperature, static electricity, etc.), the opening of the bag may vary. The films may adhere strongly to each other. When producing a large number of bags continuously or storing a large number of bags, the films of all the bags may adhere firmly to each other. Sometimes they are strongly attached to each other.

When the films at the mouth of the bag are firmly attached to each other, even if the mouth is blown with gas, the mouth may not be opened properly. In such a case, the bag is bent without being opened by the blown gas, and the mouth faces sideways, making it impossible to properly perform subsequent processing.

The present disclosure has been made in view of the circumstances described above, and an object of the present disclosure is to provide a technology that is advantageous for opening a bag more reliably.

One aspect of the present disclosure includes: a bag supporting portion that supports a bag; a gas blowing portion that blows gas onto the mouth of the bag supported by the bag supporting portion to open the mouth; and a bag mouth heating section for heating the mouth section.

The bag opening heating section may heat the opening without contacting the bag.

The bag support moves between a first stop station and a second stop station where the gas blowing part is provided, and the bag mouth heating part moves together with the bag support from the first stop station to the second stop station. The spout may be heated while the bag is in motion.

The bag opening heating section may heat the opening by contacting the bag.

The bag opening heating unit may include a pair of heating elements that can be opened and closed, and the pair of heating elements may heat the opening while sandwiching the opening of the bag.

Another aspect of the present disclosure includes a bag support for supporting a bag, a gas blowing unit for blowing gas onto the mouth of the bag supported by the bag support to open the mouth, and First, it relates to a bag opening device including a gap forming portion that forms a gap in the mouth portion.

The gap forming part may have an inclined part that is pressed against the bag.

The gas blowing part may blow the gas onto the mouth part in a state in which the inclined part is pressed against the part of the bag opposite to the mouth part through the part supported by the bag supporting part.

Another aspect of the present disclosure includes a step of heating the mouth of the bag with a bag mouth heating unit, and a step of blowing gas onto the mouth heated by the bag mouth heating unit with a gas blowing unit to open the mouth. and a bag opening method comprising:

Another aspect of the present disclosure includes a step of forming a gap in the mouth of the bag by the gap forming part; It relates to the opening process and the method of bag opening that it involves.

According to the present disclosure, it is advantageous to open the bag more reliably.

FIG. 1 is a perspective view showing an outline of an example of a packaging machine. FIG. 2A is a diagram showing an example of a bag opening method according to the first embodiment. FIG. 2B is a diagram showing an example of the bag opening method according to the first embodiment. FIG. 2C is a diagram showing an example of a bag opening method according to the first embodiment. FIG. 3A is a diagram showing an example of a bag opening method according to the second embodiment. FIG. 3B is a diagram showing an example of a bag opening method according to the second embodiment. FIG. 3C is a diagram showing an example of a bag opening method according to the second embodiment. FIG. 4A is a diagram showing an example of a bag opening method according to the third embodiment. FIG. 4B is a diagram showing an example of a bag opening method according to the third embodiment. FIG. 4C is a diagram showing an example of a bag opening method according to the third embodiment.

[First embodiment]
FIG. 1 is a schematic perspective view of an example of a packaging machine 10. As shown in FIG.

The packaging machine 10 shown in FIG. 1 is an intermittent rotary type bag filling packaging machine. The packaging machine 10 includes a turntable 21 rotatably supported by a driving device (not shown) such as a motor, and a plurality of bag support portions 22 attached to the outer periphery of the turntable 21 at equal angular intervals.

The rotary table 21 is intermittently rotated by a driving device. In FIG. 1, the rotary table 21 is shown in a see-through state by a chain double-dashed line.

Each bag supporter 22 supports the bag B, intermittently moves along a circular orbit according to the intermittent rotation of the turntable 21, and intermittently stops sequentially at the first station S1 to the eighth station S8. do.

Each bag support 22 shown in FIG. 1 has two grippers (i.e. gripper pairs) capable of gripping opposite side edges of bag B, each gripper pair such that the horizontal spacing between the two grippers is variable. is provided. The number of bag supporters 22 attached to the rotary table 21 is equal to the number of stations, and all the bag supporters 22 simultaneously intermittently stop at their respective stations.

The first station S1 is provided with a bag feeder 11 for feeding bags B (especially empty bags) to the bag support section 22 intermittently stopping at the first station S1.

The bag feeding device 11 shown in FIG. and a pick-up sucker 11c for picking up the bags B sent out by 11b one by one and delivering them to the bag support section 22 located at the first station S1.

Each bag B has two films (a front side film and a back side film) having a rectangular planar shape. The two films are adhered to each other at three edges, but not at the remaining one edge (that is, the edge forming the mouth Bm). However, the two films of each empty bag B in the first station S1 are in intimate contact with each other at the edges forming the mouth Bm.

Each film has a sealant layer and a substrate layer provided on the sealant layer. In each bag B, the sealant layers of the two films face each other, the base layer of each film is positioned outside the sealant layer, and the sealant layer is positioned between the base layers of the two films. The sealant layers adhere to each other at the edges of the three sides of the two films. The method of bonding the sealant layers together is not limited, and the sealant layers can be bonded together by adhesive bonding, melt bonding, or other bonding methods.

A printing device 12 is provided at the second station S2. The printing device 12 performs printing on the bag B supported by the bag support portion 22 . The specific printing method is not limited, and various information such as the date of manufacture may be recorded on the side surface of the bag B using ink, or various information may be recorded on the side surface of the bag B by laser engraving. may

A gas blower 13 for opening the mouth Bm of the bag B is provided at the third station S3. The gas blowing section 13 blows gas (for example, air or inert gas) onto the mouth portion Bm of the bag B supported by the bag support section 22 . At the third station S3, the distance between the grippers is adjusted so that the grippers are brought closer to each other in the horizontal direction and the front side film and the back side film of the bag B are flexed.

The fourth station S4 is provided with a liquid injection section 14 for injecting contents (especially liquid) into the bag B. As shown in FIG. The liquid injection part 14 shown in FIG. 1 has an injection nozzle, and the liquid discharged from the injection nozzle is supplied to the inside of the bag B. As shown in FIG.

The injection nozzle may be movably provided. For example, the injection nozzle may be arranged at a retracted position where the entire injection nozzle is positioned outside the bag B and an injection position where the tip of the injection nozzle is positioned inside the bag B. Alternatively, the injection nozzle may be arranged in a fixed position, essentially without movement. The liquid may be discharged from the injection nozzle positioned outside the bag B toward the open mouth Bm.

A fifth station S5 shown in FIG. 1 is an empty station. However, for the sealing process in the next station (sixth station S6), the spacing between the grippers is adjusted such that the two grippers are moved horizontally away from each other to tighten and close the mouth Bm.

Note that the fifth station S5 may be provided as a station that performs arbitrary processing. For example, if the contents to be put into the bag B include solids, a solids loading device (not shown) for loading such solids into the bag B may be provided at the fifth station S5.

A first sealing device 16 for sealing the opening Bm of the bag B is provided at the sixth station S6. A second sealing device 17 for sealing the opening Bm of the bag B is provided at the seventh station S7. Each of the first sealing device 16 and the second sealing device 17 shown in FIG. 1 has two heating plates. The opening Bm of the bag B is heated by sandwiching the opening Bm of the bag B between the two heating plates, whereby the sealing process of the opening Bm is performed.

The eighth station S8 is provided with a cooling device 18 for cooling the mouth portion Bm of the bag B (especially the sealing portion) and a discharging device 19 for sending out the bag B released from the bag support portion 22 downstream.

The cooling device 18 shown in FIG. 1 has two cooling plates. The opening Bm of the bag B is cooled by sandwiching the opening Bm between the two cooling plates. The discharge device 19 shown in FIG. 1 has a discharge chute that guides the dropping of the bags.

At the eighth station S8, after being cooled, the bag B (product bag) released from the bag supporter 22 and the cooling device 18 falls under the influence of gravity and lands on the discharge chute. is guided downstream by

In this embodiment, a bag opening heating section 31 is provided between the second station S2 and the third station S3. The bag opening heating unit 31 heats the opening Bm of the bag B before the gas blowing unit 13 blows the gas onto the opening Bm of the bag B. As shown in FIG. That is, the bag opening heating section 31 heats the bag moving together with the bag support section 22 while the bag support section 22 moves between the second station S2 (first stop station) and the third station S3 (second stop station). The mouth part Bm of B is heated without contacting the bag B.

The third station S3 may be provided with an inclined portion 32 (see FIGS. 4A to 4C), which will be described later.

2A to 2C are diagrams showing an example of the bag opening method according to the first embodiment. FIG. 2A shows an example of the state of the bag B supported by the bag support section 22 at the second station S2. FIG. 2B shows an example of the state of the bag B supported by the bag support section 22 while it is moving from the second station S2 toward the third station S3. FIG. 2C shows an example of the state of the bag B supported by the bag support section 22 at the third station S3. In FIG. 2A, illustration of the printing device 12 (see FIG. 1) is omitted.

At the second station S2, the mouth Bm of the bag B supported by the bag support 22 is basically closed as shown in FIG. 2A.

While the bag support portion 22 intermittently moves from the second station S2 toward the third station S3, the mouth portion Bm of the bag B is provided between the second station S2 and the third station S3. It is heated by the bag opening heating section 31 .

The bag mouth heating unit 31 shown in FIG. 2B has a rectangular parallelepiped heating body 31a, a heater 31b provided inside the heating body 31a, and a heating space 31c formed in the heating body 31a. The heating body 31a is heated by the heat generated by the heater 31b, and heat is radiated from the heating body 31a toward the heating space 31c.

The heating space 31c shown in FIG. 2B is configured as a rectangular parallelepiped concave portion, but the shape of the heating space 31c is not limited. For example, at least a portion of the demarcation plane (eg, the upper demarcation plane) of heating body 31a that defines heating space 31c may have a curved surface or other non-planar surface. Moreover, although the heating body 31a shown in FIG. 2B has a single block shape, the heating body 31a may include a plurality of members (for example, two plates), and the heating space 31c may be defined by the plurality of members.

The mouth portion Bm of the bag B moving together with the bag support portion 22 toward the third station S3 passes through the heating space 31c and receives radiant heat from above and from both sides (that is, in the thickness direction) while passing through the heating space 31c. received and heated.

The front side film and the back side film that form the mouth portion Bm of the bag B are thus heated by the bag mouth heating section 31 to expand, forming a gap between the two films or fixing the two films. is reduced.

The heating temperature of the mouth portion Bm by the bag mouth heating portion 31 is not limited. For example, the bag B may be heated by the bag opening heating section 31 so that the opening Bm has a temperature at which the front side film and the back side film (for example, the sealant layer) melt.

Then, when the bag B is placed at the third station S3, the gas blowing unit 13 blows the gas G onto the mouth portion Bm heated by the bag mouth heating unit 31. As shown in FIG. That is, the gas G (for example, compressed air) is jetted from the gas flow path 13 a of the gas blowing portion 13 toward the mouth portion Bm in which the gap is formed by the heat treatment by the bag mouth heating portion 31 . As a result, the gas G advances inside the bag B through the gap of the mouth portion Bm, and the mouth portion Bm is opened more widely.

As described above, the bag opening device of the present embodiment has the bag support portion 22 that supports the bag B, and blows the gas G onto the mouth portion Bm of the bag B supported by the bag support portion 22 to open the mouth portion Bm. A gas blowing part 13 and a bag mouth heating part 31 for heating the mouth part Bm prior to blowing the gas G to the mouth part Bm are provided.

In addition, the bag opening method of the present embodiment includes the steps of heating the mouth portion Bm of the bag B by the bag mouth heating portion 31, and a step of blowing G to open the mouth Bm.

In particular, according to the above example, the bag mouth heating section 31 (heating body) is installed on the route before the third station S3 where the opening process is performed, and the bag B fills the heating space 31c of the bag mouth heating section 31. By passing through, the opening Bm is heated and stretched or expanded, and the film of the bag B is warped outward.

As a result, the close contact between the films of the bag B can be eliminated or reduced, which is advantageous for more reliably opening the bag.

Moreover, the bag mouth heating part 31 heats the mouth part Bm without contacting the bag B. As shown in FIG. According to the bag opening heating unit 31 adopting such a non-contact heating method, the opening Bm can be heated without damaging the bag B.

Further, the bag support section 22 moves between a second station S2 (first stop station) and a third station S3 (second stop station) where the gas blowing section 13 is provided, and the bag opening heating section 31 The mouth portion Bm is heated while the bag B is moving from the second station S2 toward the third station S3 together with the bag support portion 22.例文帳に追加By heating the mouth portion Bm while moving the bag B in this manner, the bag mouth heating portion 31 can be installed between the stations (that is, between the intermittent stop positions). As a result, the space between stations can be effectively used, and the density of devices in the stations can be suppressed.

[Second embodiment]
In this embodiment, the same reference numerals are given to the same or corresponding elements as in the above-described first embodiment, and detailed description thereof will be omitted.

3A to 3C are diagrams showing an example of the bag opening method according to the second embodiment. FIG. 3A shows an example of the state of the bag B supported by the bag support section 22 at the second station S2. FIG. 3B shows an example of the state of the bag B supported by the bag support section 22 moving from the second station S2 toward the third station S3. FIG. 3C shows an example of the state of the bag B supported by the bag support section 22 at the third station S3. In FIG. 3A, illustration of the printing device 12 (see FIG. 1) is omitted.

The bag opening heating section 31 of this embodiment is provided in the second station S2.

The bag opening heating part 31 shown in FIG. 3A has two heating bodies 31a, each heating body 31a having a heater 31b, and each heating body 31a being heated by the corresponding heater 31b. A heating space 31c is provided between the two heating bodies 31a. The two heating bodies 31a are provided movably in the thickness direction (horizontal direction) of the bag B, and are arranged at a close position and a spaced position.

The distance between the two heating bodies 31a (that is, the size of the heating space 31c in the horizontal direction) is greater than the thickness of the mouth portion Bm of the bag B when the two heating bodies 31a are arranged at the separated position. On the other hand, in a state where the mouth portion Bm of the bag B is positioned between the two heating bodies 31a and the two heating bodies 31a are arranged at close positions, the mouth portion Bm contacts the two heating bodies 31a, It is sandwiched and pressed by two heating main bodies 31a.

As described above, the bag mouth heating unit 31 of the present embodiment includes a pair of heating bodies 31a (heating bodies) that can be opened and closed, and the pair of heating bodies 31a cover the mouth part Bm in a state where the bag B is stopped. Place and heat.

In this embodiment, while the bag B supported by the bag support section 22 is intermittently stopped at the second station S2, the bag mouth heating section 31 contacts the bag B to heat the mouth section Bm. .

That is, when the bag B supported by the bag support portion 22 is moved from the first station S1 and placed in the second station S2, the two heating main bodies 31a are placed in a separated position, and the mouth portion Bm of the bag B is heated. Enter between the spaces 31c and stop at the heating space 31c. Then, while the bag B is arranged at the second station S2, the two heating bodies 31a are moved from the separated position to be arranged at the close position while the printing device 12 performs the printing process. As a result, the mouth portion Bm of the bag B is sandwiched between the two heating bodies 31a arranged at close positions and heated. By this heat treatment, a gap is formed in the mouth portion Bm or the degree of fixation between the films forming the mouth portion Bm is reduced.

In addition, the size of each heating main body 31a is not limited. Each heating main body 31a may heat the entire opening Bm of the bag B while being in contact with the entire opening Bm (upper edge of the bag B). Alternatively, each heating main body 31a contacts only a portion of the mouth portion Bm of the bag B (for example, a portion including a portion where the gas G is directly blown from the gas blowing portion 13 (for example, the central portion in the horizontal direction)), Bm may be heated.

After the mouth portion Bm of the bag B is sufficiently heated by the two heating bodies 31a, the two heating bodies 31a are moved from the close position to the separated position. Then, with the two heating bodies 31a arranged at the separated positions, the bag support part 22 and the bag B are moved from the second station S2 and arranged at the third station S3.

As described above, the strength of adhesion between the two films forming the mouth portion Bm of the bag B sufficiently heated by the bag mouth heating section 31 at the second station S2 is reduced. After that, even if the temperature of the two films forming the mouth portion Bm is lowered, the weakened state of adhesion between the two films is maintained. Therefore, a gap may be formed at the mouth portion Bm of the bag B while the bag B is moving from the second station S2 to the third station S3 (see FIG. 3B).

After that, similarly to the above-described first embodiment, the gas G is blown from the gas blowing section 13 to the mouth Bm of the bag B at the third station S3, and the mouth Bm is wide opened (see FIG. 3C).

As described above, according to the present embodiment, the bag opening heating section 31 contacts the bag B to heat the opening Bm. Thereby, the mouth portion Bm can be efficiently heated in a short time.

The bag opening heating unit 31 includes a pair of heating bodies 31a (heating bodies) that can be opened and closed. Thereby, the mouth portion Bm can be heated more efficiently in a short time.

In particular, since the bag mouth heating part 31 contacts the bag B while the bag B is stopped, the bag mouth heating part 31 can heat the mouth part Bm without damaging the bag B.

The bag mouth heating unit 31 shown in FIG. 3A heats the mouth Bm of the bag B while being in contact with the mouth Bm, but the bag mouth heating unit 31 may heat the mouth Bm in a non-contact state. . For example, the distance between the two heating bodies 31a arranged at close positions may be larger than the thickness of the mouth portion Bm of the bag B.

[Third embodiment]
In this embodiment, the same or corresponding elements as those in the above-described first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

4A to 4C are diagrams showing an example of the bag opening method according to the third embodiment, showing an example of the state of the bag B supported by the bag support section 22 at the third station S3.

Also in this embodiment, before the gas G is blown to the mouth portion Bm of the bag B, a gap is formed in the mouth portion Bm by the gap forming portion. However, the gap forming portion of this embodiment has an inclined portion 32 that is pressed against the bag B instead of the bag opening heating portion 31 .

In the example shown in FIGS. 4A to 4C, the inclined portion 32 is provided at the third station S3, and the portion of the bag B below the portion gripped by the bag support portion 22 (the bag support portion 22 is is pressed against the portion on the side opposite to the mouth portion Bm).

That is, while the bag B supported by the bag support portion 22 is intermittently stopped at the third station S3 (FIG. 4A), the inclined portion 32 moves from a position spaced apart from the bag B and moves toward the bag B. pressed (Fig. 4B). The movement of the tilting part 32 at this time is not limited. It may rotate like this.

By pressing the slanted portion 32 against the bag B, the film of the bag B with which the slanted portion 32 contacts is pulled, and a gap is formed at the mouth portion Bm of the bag B. Specifically, the mouth portion Bm moves in the tilt direction of the bag B corresponding to the direction in which the portion of the bag B that is in contact with the tilt portion 32 moves, and a gap is formed in the mouth portion Bm. However, when the inclined portion 32 is pressed against the bag B, both side edges of the bag B are fixedly gripped by the bag support portion 22, so the position of the mouth portion Bm is maintained to some extent and does not move significantly.

After the gap is formed in the mouth portion Bm of the bag B by the inclined portion 32 in this manner, the gas blowing portion 13 blows the gas G onto the mouth portion Bm, thereby opening the mouth portion Bm more widely (FIG. 4C). .

In the example shown in FIG. 4C, in a state in which the inclined portion 32 is pressed against the portion of the bag B on the side opposite to the mouth portion Bm through the portion supported by the bag support portion 22, the gas blowing portion 13 A gas G is blown to the mouth Bm. After the gap is formed in the mouth portion Bm by the inclined portion 32, the mouth portion Bm is opened by blowing the gas G to the mouth portion Bm by the gas blowing portion 13 while the inclined portion 32 is separated from the bag B. may

As described above, the bag opening device of the present embodiment has the bag support portion 22 that supports the bag B, and blows the gas G onto the mouth portion Bm of the bag B supported by the bag support portion 22 to open the mouth portion Bm. It includes a gas blowing portion 13 and a gap forming portion (inclined portion 32) that forms a gap in the mouth portion Bm prior to blowing the gas G onto the mouth portion Bm.

Further, the bag opening method of the present embodiment includes the step of forming a gap in the mouth portion Bm of the bag B by the gap forming portion (tilted portion 32), and after the gap is formed in the mouth portion Bm, by the gas blowing portion 13, and a step of blowing gas G onto the mouth Bm to open the mouth Bm.

By forming a gap in the mouth portion Bm prior to blowing the gas G onto the mouth portion Bm in this manner, the mouth portion Bm can be more reliably opened when the gas G is blown onto the mouth portion Bm.

In particular, the gap forming part of the example described above has an inclined part 32 that is pressed against the bag B. As shown in FIG.

By physically applying a force to the bag B by the inclined portion 32 in this way, it is possible to more reliably form a gap in the mouth portion Bm. For example, depending on the material of the bag B, even if the bag B is heated by the above-described bag opening heating unit 31 (FIGS. 2A to 3C), it may be difficult to form a gap of sufficient size in the opening Bm. . As an example, when the intermittent stop time (intermittent movement time) of the bag supporting portion 22 and the bag B is short, even if the bag mouth heating portion 31 heats the bag B, a gap of sufficient size cannot be formed in the mouth portion Bm. There is Even in such a case, according to the inclined portion 32 of the present embodiment, it is possible to appropriately form a gap in the mouth portion Bm.

Further, the gas blowing part 13 sprays the gas onto the mouth part Bm in a state where the inclined part 32 is pressed against the part of the bag B opposite to the mouth part Bm through the part supported by the bag support part 22 . Spray G.

Thereby, the gas G can be blown to the mouth portion Bm while maintaining the gap in the mouth portion Bm, and the mouth portion Bm can be opened more reliably.

[Modification]
In the above-described first embodiment, the bag opening heating section 31 is provided between the second station S2 and the third station S3, and in the second embodiment, the bag opening heating section 31 is provided in the second station S2. , the bag opening heating unit 31 may be provided in the third station S3. That is, before the gas G is blown from the gas blowing section 13 to the mouth portion Bm of the bag B, the mouth portion Bm may be heated by the bag mouth heating portion 31 provided at the third station S3.

The bag opening heating section 31 provided at the third station S3 may continue to heat the opening Bm of the bag B while the gas G is being blown from the gas blowing section 13 to the opening Bm of the bag B.

Although the tilting section 32 is provided at the third station S3 in the above-described third embodiment, the tilting section 32 may be provided at a stage prior to the third station S3. That is, after the inclined portion 32 is pressed against the bag B before the third station S3 to form a gap in the mouth portion Bm, the bag B moves to the third station S3 together with the corresponding bag support portion 22. The gas G may be blown by the gas blowing unit 13 .

Various modifications may be added to each element of the above-described embodiments and modifications, and configurations may be partially or wholly combined between the above-described embodiments and modifications. Further, the effects achieved by the present disclosure are not limited to the above-described effects, and specific effects according to the specific configurations of each embodiment can also be exhibited. Thus, various additions, changes, and partial deletions can be made to each element described in the claims, specification, and drawings without departing from the technical spirit and spirit of the present disclosure.

REFERENCE SIGNS LIST 10 packaging machine, 11 bag feeder, 11a conveyor magazine, 11b delivery roller, 11c extraction sucker, 12 printer, 13 gas blowing section, 13a gas flow path, 14 liquid injection section, 16 first sealing device, 17 second seal Apparatus 18 Cooling device 19 Ejecting device 21 Rotating table 22 Bag supporting part 31 Bag opening heating part 31a Heating main body 31b Heater 31c Heating space 32 Inclined part S1 First station S2 Second station S3 3rd station, S4 4th station, S5 5th station, S6 6th station, S7 7th station, S8 8th station, B Bag, Bm Mouth, G Gas

Claims (10)

a bag support that supports the bag;
a gas blowing unit for blowing gas onto the mouth of the bag supported by the bag support to open the mouth;
and a bag mouth heating section for heating the mouth prior to blowing the gas onto the mouth. 2. The bag opening device according to claim 1, wherein the bag opening heating unit heats the opening without contacting the bag. said bag support moves between a first stop station and a second stop station at which said gas blower is provided;
3. The bag mouth heating part according to claim 1 or 2, wherein the mouth part is heated while the bag is moving from the first stop station toward the second stop station together with the bag support part. Bag opening device. 2. The bag opening device according to claim 1, wherein the bag opening heating section heats the opening by contacting the bag. The bag opening heating unit includes a pair of heating elements that can be opened and closed,
5. The bag opening device according to claim 4, wherein the pair of heating members heats the opening while the bag is stopped. a bag support that supports the bag;
a gas blowing unit for blowing gas onto the mouth of the bag supported by the bag support to open the mouth;
a gap forming part for forming a gap in the opening before blowing the gas to the opening. 7. The bag opening device according to claim 6, wherein the gap forming portion has an inclined portion that is pressed against the bag. The gas blowing part is configured to press the inclined part against the part of the bag opposite to the mouth part through the part supported by the bag support part, and to blow the gas onto the mouth part. 8. The bag opening device according to claim 7, wherein the spraying of heating the mouth of the bag with a bag mouth heating unit;
A method for opening a bag, comprising: blowing a gas from a gas blowing unit onto the opening heated by the bag opening heating unit to open the opening. forming a gap in the mouth of the bag with the gap forming part;
A method for opening a bag, comprising: after the gap is formed in the opening, a gas blowing unit blows gas onto the opening to open the opening.

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