JP2015013390A - Bag-making machine and bag-making method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag-making machine and a bag-making method where: preheating can be performed once by preheating a plurality of belt-like films in a superposed state; the productivity of a bag body can be enhanced in comparison with such a conventional technique that a plurality of times of preheating are performed; and space-saving can be achieved.SOLUTION: The bag-making machine comprises: an ultrasonic welding section (for example, an ultrasonic welding mechanism 50) where the preheating of a plurality of belt-like films W in a superposed state is performed by ultrasonic welding; and a heat seal section (for example, a heat seal plate 42) where the finishing heat sealing of the plurality of belt-like films W preheated in the ultrasonic welding section is performed.

Description

  The present invention relates to a bag making machine and a bag making method for producing a bag body from a belt-like film.

  2. Description of the Related Art Conventionally, various types of bag making machines for producing a bag (product) from a film such as a belt-shaped plastic film are known (see, for example, Patent Document 1). In a general bag making machine, a belt-like film is fed from a paper feed roll, and the fed film is cut into two at the center position in the width direction by a center blade, and the inner surfaces of the two cut films are separated from each other. It is superimposed in a state of facing each other. At this time, the thermoplastic resin layers in each of the two-layer belt-like films come to face each other.

  Thereafter, a bag body (plastic bag) is manufactured by applying various treatments to each of the two-layered belt-shaped films superimposed by each movable unit. Specifically, a vertical heat seal plate, a vertical cooling plate, a horizontal heat seal plate, a horizontal cooling plate, and a cutting blade are used as the movable unit, and a bag body is manufactured for each intermittent feed of the film.

  In a general bag-making process using a conventional bag-making machine, heat is applied to a two-layer belt film that is intermittently conveyed when performing horizontal sealing on the two-layer film that has been stacked. After preheating (preheating) using a sealing plate 2 to 3 times to sufficiently increase the inner surface temperature of these films, thermocompression bonding is performed along the width direction of the film with a finishing heat sealing plate ing. However, in such a bag making process, since it is necessary to perform preheating using a heat seal plate a plurality of times, it is necessary to prepare a plurality of heat seal plates for preheating, and alignment of these heat seal plates In other words, there is a problem that it takes time to adjust the position in the film conveyance direction. In addition, in the heating method in which preheating is performed a plurality of times using a heat seal plate, such as the bag making process described above, the rate of temperature rise of the inner surface temperature of the film is small, so the production rate of the bag cannot be increased. There's a problem.

  On the other hand, in the bag making apparatus as disclosed in Patent Document 2, in order to perform bag making at a high speed, thermocompression bonding is performed from the outer surface of the film as described above using a heat seal plate or the like. Instead of this method, a method is used in which the inner surface of a film which is a thermoplastic resin layer is heated and melted with a heat seal roll or hot air, and the inner surfaces of the melted film are pressure-bonded. However, when introducing a bag making apparatus as disclosed in Patent Document 2, it is necessary to introduce a completely new production line, and more installation space is required due to the enlargement of the apparatus. There is a problem.

Japanese Patent No. 4902796 JP 2007-204110 A

  The present invention has been made in consideration of such points, and the number of times of preheating is set to one by performing preheating by ultrasonic welding on a plurality of strip-shaped films in an overlapped state. Therefore, it is possible to provide a bag making machine and a bag making method that can improve the productivity of the bag body and can save space as compared with the conventional technique in which preheating is performed a plurality of times. For the purpose.

  The bag making machine of the present invention includes a transport unit that transports a plurality of strip-shaped films along the longitudinal direction of the film, and a plurality of stacked films that are transported by the transport unit. An ultrasonic welding part that preheats the belt-like film by ultrasonic welding, and a heat seal part that heat-finishes the plurality of belt-like films preheated by the ultrasonic welding part, It is provided with.

  According to such a bag making machine, preheating is performed by ultrasonic welding on a plurality of strip-shaped films in an overlapped state, and then the plurality of strip-shaped films preheated by ultrasonic welding is applied. On the other hand, by finishing heat sealing, the number of times of preheating can be reduced to one, thereby improving the productivity of the bag body as compared with the conventional technique in which preheating is performed a plurality of times. And space saving.

  In the bag making machine of the present invention, the ultrasonic welding unit includes an ultrasonic horn, a vibrator unit that applies vibration energy to the ultrasonic horn, and a receiving unit that receives the ultrasonic horn, A plurality of strip-shaped films in a pressed state are pressed by the ultrasonic horn and received by the receiving portion, and the ultrasonic horn vibrates ultrasonically to weld the thermoplastic resin layers of the films. It may be like this.

  At this time, the surface of the ultrasonic horn in contact with the film or the surface of the receiving portion may be uneven.

  In this case, the uneven shape may be provided by knurling.

  In the bag making machine of the present invention, the ultrasonic welding portion is configured to perform preheating by ultrasonic welding along the width direction with respect to a plurality of strip-shaped films in an overlapped state, The heat seal part may be configured to perform a final heat seal along a width direction of the plurality of strip-shaped films preheated by the ultrasonic welding part.

  Alternatively, the ultrasonic welding portion is configured to perform preheating on the plurality of strip-shaped films in an overlapped state by ultrasonic welding at both side edges thereof, and the heat seal portion includes the supersonic welding portion. A plurality of strip-shaped films that have been preheated by the sonic welding portion may be subjected to finishing heat sealing at both side edges.

  The bag-making method of the present invention includes a step of conveying a plurality of strip-shaped films along the longitudinal direction of the film in a state of being superimposed, and an ultrasonic wave for the plurality of strip-shaped films in the superimposed state. The method includes a step of performing preheating by welding and a step of performing heat sealing for finishing a plurality of strip-shaped films that have been preheated by ultrasonic welding.

  According to such a bag making method, preheating is performed by ultrasonic welding on a plurality of strip-shaped films in an overlapped state, and then the plurality of strip-shaped films preheated by ultrasonic welding is applied. On the other hand, by finishing heat sealing, the number of times of preheating can be reduced to one, thereby improving the productivity of the bag body as compared with the conventional technique in which preheating is performed a plurality of times. And space saving.

  According to the bag making machine and the bag making method of the present invention, the number of times of preheating can be set to one by performing preheating by ultrasonic welding on a plurality of strip-shaped films in an overlapped state, For this reason, productivity of a bag body can be improved and space saving can be achieved compared with the prior art which performs preheating several times.

It is a block diagram which shows the whole structure of the bag making machine by embodiment of this invention. It is a perspective view which shows the structure of the ultrasonic welding mechanism provided in the bag making machine shown in FIG. It is a side view when the ultrasonic welding mechanism shown in FIG. 2 is seen from the side. It is a perspective view which shows the knurl process given to the surface of the lower metal mold | die in the ultrasonic welding mechanism shown in FIG. It is a block diagram which shows the whole structure of the conventional bag making machine as a comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are diagrams showing a bag making machine according to the present embodiment. Among these, FIG. 1 is a block diagram showing the overall configuration of the bag making machine according to the present embodiment, and FIG. 2 is a perspective view showing the configuration of an ultrasonic welding mechanism provided in the bag making machine shown in FIG. It is. 3 is a side view when the ultrasonic welding mechanism shown in FIG. 2 is viewed from the side, and FIG. 4 is applied to the surface of the lower mold in the ultrasonic welding mechanism shown in FIG. It is a perspective view which shows knurl processing. In addition, FIG. 5 is a block diagram which shows the whole structure of the conventional bag making machine as a comparative example.

  First, the overall configuration of the bag making machine according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, in the bag making machine according to the present embodiment, a belt-like film W is fed out from a paper feed roll 10. The strip-shaped film W is repeatedly printed with a print pattern with a constant print pitch (product pitch), and a detection mark is provided for each print pitch in the vicinity of the side edge of the film W. Further, the transport direction of the film W fed out from the paper feed roll 10 is changed by an angle of 90 ° by the turn bar 12 (specifically, on the upstream side of the turn bar 12 in the transport direction of the film W). The film W extends in a direction perpendicular to the paper surface of FIG. 1, but the direction of the film W is changed by the turn bar 12 so that it extends along the paper surface of FIG. Thereafter, the film W is continuously conveyed by the first nip roll 20. At this time, the film W is guided by the guide roll 29. Further, the film W continuously conveyed by the first nip roll 20 is cut into two at the center position in the width direction by the center blade 14, and the two cut films W are each 90 ° by the M-shaped plate 16. The direction is changed again at an angle of and the inner surfaces are overlapped to face each other (specifically, the two films W are upstream of the M-shaped plate 16 in the transport direction of the film W along the plane of FIG. 1). However, the conveying direction of each film W is changed by the M-shaped plate 16 so as to extend in a direction perpendicular to the paper surface of FIG. 1). At this time, the sealant layers in each of the two strip-shaped films W face each other. Here, the sealant layer in the film W refers to a thermoplastic resin layer such as unstretched polypropylene (CPP) or polyethylene (PE).

  Thereafter, the two strip-shaped films W are overlapped, and the two-layered strip-shaped films W are intermittently conveyed by the second nip roll 24, the third nip roll 26, and the fourth nip roll 28. Specifically, the second nip roll 24, the third nip roll 26, and the fourth nip roll 28 continuously convey the two-layer belt-shaped film W that is overlaid by a certain amount of movement, and then for a certain period. Only the operation to stop the conveyance is repeated.

  In the present embodiment, the second nip roll 24, the third nip roll 26, and the fourth nip roll 28 are used to superimpose a plurality (specifically, two layers) of the belt-like films W on each other. The conveyance part conveyed along the longitudinal direction of the film W is comprised.

  Further, on the upstream side of the second nip roll 24 in the conveyance direction of the film W, two dancer rolls 22 that are movable in the vertical direction in FIG. 1 are provided, and each dancer roll 22 has a center blade. After being cut by 14, they are stretched on the two strip-shaped films W before being superposed. Each dancer roll 22 is continuously moved in the vertical direction in FIG. 1, thereby switching the transport mode of the belt-like film W from continuous transport to intermittent transport.

  As shown in FIG. 1, a vertical seal portion 30 is provided between the second nip roll 24 and the third nip roll 26 in the film W conveyance direction. The vertical seal portion 30 is configured to perform sealing at both side edge portions on the two-layered strip-shaped film W in an overlapped state. Specifically, the vertical seal portion 30 includes an elongated heat seal plate (heat seal bar) 32 that performs heat seal on both side edges of the two-layered strip-shaped film W in an overlapped state, and the film W. And a cooling plate (cooling bar) 34 that is provided downstream of the heat seal plate 32 in the conveying direction and cools both side edges where the band-like film W is sealed.

  Further, as shown in FIG. 1, a lateral seal portion 40 is provided between the third nip roll 26 and the fourth nip roll 28 in the film W conveyance direction. The horizontal seal portion 40 is configured to seal the two-layered strip-shaped film W in an overlapped state along the width direction. Specifically, the horizontal seal portion 40 includes an ultrasonic welding mechanism 50 that performs preheating by ultrasonic welding along the width direction of the two-layered strip-shaped film W in an overlapped state, and the film W. Heat that is provided on the downstream side of the ultrasonic welding mechanism 50 in the conveying direction of the sheet and performs heat sealing for finishing along the width direction of the two-layer belt-like film W preheated by the ultrasonic welding mechanism 50 A seal plate and a plurality of cooling plates (cooling bars) provided on the downstream side of the heat seal plate in the transport direction of the film W and for cooling the film W sealed in the width direction. Yes. Further, the ultrasonic welding mechanism 50, the heat seal plate 42, and each cooling plate 44 in the horizontal seal portion 40 correspond to the print pitch (product pitch) of the printed pattern repeatedly printed on the film W in the transport direction of the film W. It is provided at a position that is spaced apart. Details of the configuration of the ultrasonic welding mechanism 50 will be described later.

  Further, a cutting blade 46 is provided on the downstream side of the fourth nip roll 28 in the conveyance direction of the film W, and the two-layer belt-like film W sealed by the vertical seal portion 30 and the horizontal seal portion 40 is as follows. The cutting blade 46 is cut into two at the center position in the width direction and cut along the width direction. In this way, a bag body (specifically, a plastic bag) W ′ as a product is manufactured.

  As shown in FIG. 1, a mark sensor 80 including an optical sensor and a CCD camera is installed on the upstream side of the vertical seal portion 30 in the transport direction of the film W, and a detection mark attached to the film W is displayed. The mark sensor 80 detects the mark. In addition, a mark sensor 82 including an optical sensor, a CCD camera, and the like is installed on the downstream side of the horizontal seal portion 40 in the transport direction of the film W, and a detection mark attached to the film W is detected by the mark sensor 82. It has become so.

  Next, the configuration of the ultrasonic welding mechanism 50 of the horizontal seal portion 40 will be described in detail with reference to FIGS. As described above, FIG. 2 is a perspective view showing the configuration of the ultrasonic welding mechanism 50 provided in the bag making machine shown in FIG. 1, and FIG. 3 is a side view of the ultrasonic welding mechanism 50 shown in FIG. 4 is a side view when viewed from above, and FIG. 4 is a perspective view showing knurling applied to the surface of the lower mold 72 in the ultrasonic welding mechanism 50 shown in FIG. In FIGS. 2 and 3, the transport direction of the two-layer belt-like film W is indicated by an arrow.

  As shown in FIGS. 2 and 3, the ultrasonic welding mechanism 50 has a solid ultrasonic horn 52 and a vibrator portion 54 so that vibration energy is given to the ultrasonic horn 52 by the vibrator portion 54. It has become. More specifically, as shown in FIG. 2, an oscillator 55 is connected to the vibrator unit 54. The oscillator 55 converts an electric signal of 50 Hz or 60 Hz into an electric signal of 20 kHz, for example, and is amplified. The electrical signal transmitted to the vibrator portion 54 is converted into mechanical vibration energy by the vibrator portion 54.

  As shown in FIGS. 2 and 3, the ultrasonic welding mechanism 50 is provided with an air cylinder 56, and the ultrasonic horn 52 is pushed downward in FIGS. 2 and 3 by the air cylinder 56. It has become. Specifically, a push air supply line 58 and a pull air supply line 60 are respectively connected to the air cylinder 56, and a push air supply unit 62 is connected to the push air supply line 58 and pulled. A pulling air supply unit 64 is connected to the air supply line 60. When the compressed air is sent from the pushing air supply unit 62 to the pushing air supply line 58 while the conveyance of the two-layer belt-like film W is stopped, the air cylinder 56 moves down the ultrasonic horn 52. The lower end of the ultrasonic horn 52 comes into contact with the upper film W of the two layers of the belt-like film W. At this time, since the ultrasonic horn 52 is ultrasonically vibrated by the vibrator portion 54, the sealant layer (thermoplastic resin layer) in the upper film W is melted and welded to the sealant layer in the lower film W. It becomes like this. In this way, preheating (preheating) is performed on the two-layered belt-like film W. On the other hand, when compressed air is sent from the pulling air supply unit 64 to the pulling air supply line 60, the air cylinder 56 retracts the ultrasonic horn 52 upward, and the lower end of the ultrasonic horn 52 has two layers. The band-shaped film W is separated upward from the upper film W. As another mode of the ultrasonic welding mechanism 50, the ultrasonic horn 52 is pushed downward in FIGS. 2 and 3 by a servo motor (not shown) instead of the air cylinder 56, and the film W is pressed. May be.

  As shown in FIGS. 2 and 3, the ultrasonic horn 52, the vibrator portion 54, the air cylinder 56, and the like are supported by a support frame 74. Further, the ultrasonic welding mechanism 50 is provided with an LM guide (linear motion guide) 66, and the above-described linear motion of the ultrasonic horn 52, the vibrator portion 54, etc. by the air cylinder 56 is caused by the LM guide 66. Guided. Further, as shown in FIG. 3, a damper 68 is provided below the air cylinder 56, so that the downward pressing force applied to the ultrasonic horn 52 by the air cylinder 56 is relieved by the damper 68. It has become.

  Further, as shown in FIGS. 2 and 3, a lower plate 70 is provided below the two-layer belt-like film W, and the lower plate 70 is pushed downward by an air cylinder 56. A lower mold 72 is provided as a receiving portion for receiving the lower end portion of the ultrasonic horn 52. When the ultrasonic horn 52 is pushed downward by the air cylinder 56, the lower end portion of the ultrasonic horn 52 is received by the lower mold 72, and the lower end portion and the lower mold of the ultrasonic horn 52 are received. Between the upper surface of 72, welding between the two-layered strip-like films W is performed.

  In the present embodiment, as shown in FIG. 4, the surface of the lower mold 72 (the surface of the two-layered strip-shaped film W that contacts the lower film W) is knurled. Yes. Here, knurling means forming a mesh-like unevenness on the surface of the lower mold 72. By performing such knurl processing on the surface of the lower mold 72, a two-layer belt-like shape is formed between the lower end portion of the ultrasonic horn 52 and the surface of the lower mold 72 in the ultrasonic welding mechanism 50. When the film W is welded, the contact area of the film W with the surface of the lower mold 72 is reduced, so that a larger pressure is applied to the portion of the film W that is in contact with the surface of the lower mold 72. It is possible to perform sufficient preheating on the two-layer belt-like film W.

  Next, as a comparative example, the conventional two-layer belt-like film W is not preheated by the ultrasonic welding mechanism 50 but is preheated by a plurality of heat seal plates 42. An embodiment of the bag making machine will be described with reference to FIG.

  In the conventional bag making machine as shown in FIG. 5, a total of four heat seal plates 42 are provided in the lateral seal portion 40, of which the three heat seal plates 42 in the preceding stage are used to form a two-layer belt-like film W. In addition, preheating is performed, and finishing heat sealing is performed on the preheated film W by one heat sealing plate 42 in the subsequent stage. However, in such a conventional bag making machine, it is necessary to prepare a plurality of heat seal plates 42 for preheating (three in the example shown in FIG. 5), and alignment of these heat seal plates 42 (ie, There is a problem that it takes time to adjust the position of the film W in the longitudinal direction. Further, in the heating method in which preheating is performed a plurality of times using the heat seal plate 42, the rate of temperature rise of the inner surface temperature of the film W is small, so the production rate of the bag body (specifically, the plastic bag) W ′ is increased. There is a problem that can not be.

  On the other hand, according to the bag making machine and the bag making method of the present embodiment configured as shown in FIGS. 1 to 4, the two-layer belt-like film W in an overlapped state is used. In the ultrasonic welding mechanism 50, preheating is performed by ultrasonic welding, and then a final heat seal is performed on the two-layered film W that has been preheated by ultrasonic welding. Here, when pre-heating is performed by ultrasonic welding on the two-layered strip-shaped film W in an overlapped state, a sealant layer (thermoplasticity is generated using frictional heat due to friction between the inner surfaces of the film W. Since the resin layer) is heated, the heat transfer efficiency is higher than the heating method from the outside like the conventional bag making machine shown in FIG. 5, and the two-layer belt-like film W is formed by one preheating. The temperature can be raised to a desired temperature in a short time. On the other hand, it is difficult to control the temperature with a heating method using ultrasonic welding, and it is difficult to heat-finish the two-layered film W with such a heating method using ultrasonic welding. By performing the heat seal of the finish using the heat seal plate 42 after the preheating according to the above, it is possible to reliably perform a desired seal along the width direction of the film W with respect to the two-layered film W. become. As described above, in the present embodiment, the total heat sealing in the horizontal sealing portion 40 is achieved by limiting the ultrasonic welding to the two-layered strip-shaped film W in the superposed state to the temperature rising application in the preheating. The time can be shortened, and therefore the production speed of the bag body W ′ can be improved.

  Further, in the conventional bag making machine as shown in FIG. 5, preheating is performed by a plurality of heat seal plates 42, but in the present embodiment, by adopting an ultrasonic welding method by the ultrasonic welding mechanism 50, One mechanism is sufficient for preheating the belt-shaped film W of the layers. For this reason, in the conventional bag making machine, it took a lot of time to align the plurality of heat seal plates 42, but in this embodiment, such adjustment time (setup time) is reduced. Can do. Further, in the conventional bag making machine, when the plurality of heat seal plates 42 are aligned, the adjustment film W is fed out from the paper feed roll 10 and the film W is used to align the heat seal plates 42 for preheating. However, in this embodiment, the amount of the adjustment film W can be reduced. Furthermore, in this embodiment, the number of installed heat seal plates 42 can be reduced compared to a conventional bag making machine, so that space saving can be achieved, and the conventional bag making machine can be attached. It becomes possible to introduce inspection devices such as optical sensors and CCD cameras that were not present. Thus, the quality of the bag body W ′ manufactured by the bag making machine can be improved.

  Further, in the conventional bag making machine as shown in FIG. 5, preheating is performed by the plurality of heat seal plates 42, but the heating of the film W by such a plurality of heat seal plates 42 consumes a lot of electric power. There was a problem that. On the other hand, in this embodiment, since the power-saving ultrasonic welding mechanism 50 is used when preheating the two-layer belt-like film W, power saving is achieved in the entire bag making machine. Running costs can be reduced.

  Further, the configuration of the present invention can be easily applied to an existing bag making machine that preheats a two-layer belt-like film W with a plurality of heat seal plates 42 as shown in FIG. it can. That is, the present invention as shown in FIG. 1 is obtained by removing the three heat seal plates 42 for preheating from the existing bag making machine as shown in FIG. 5 and installing the ultrasonic welding mechanism 50 instead. The bag making machine can be configured.

  As described above, according to the bag making machine and the bag making method of the present embodiment, preheating is performed by ultrasonic welding on the two-layered strip-shaped film W in an overlapped state, and then the ultrasonic wave Conventionally, the number of times of preheating can be reduced to one by performing the final heat sealing on the two-layered belt-like film W that has been preheated by welding. Compared with the technology, productivity of the bag body W ′ can be improved and space saving can be achieved.

  In the bag making machine of the present embodiment, as described above, the ultrasonic welding mechanism 50 includes the ultrasonic horn 52, the vibrator unit 54 that applies vibration energy to the ultrasonic horn 52, and the ultrasonic horn 52. A lower mold 72 (receiving part) for receiving the two-layered strip-shaped film W which is overlaid on the surface of the lower mold 72 by being pushed by the ultrasonic horn 52. When the ultrasonic horn 52 is ultrasonically vibrated in the received state, the sealant layer (thermoplastic resin layer) of each film W is welded.

  Further, in the bag making machine of the present embodiment, as described above, a mesh-like uneven shape is provided over the entire surface of the lower mold 72. Specifically, the pitch between the peaks in the mesh-like uneven shape on the surface of the lower mold 72 is, for example, about 0.4 to 0.7 mm, and the height difference between the peaks and valleys is, for example, about 0.1 mm. It has become. Such a concavo-convex shape is provided by knurling, for example. Due to the concavo-convex shape of the surface of the lower mold 72, the two-layer belt-like film W is welded between the lower end portion of the ultrasonic horn 52 and the surface of the lower mold 72 in the ultrasonic welding mechanism 50. When performing, heat can be uniformly applied to the entire surface of the film W. If the surface of the lower end portion of the ultrasonic horn 52 and the surface of the lower mold 72 are each flat, the entire surface of the film W is affected by the surface accuracy of these surfaces during ultrasonic welding. In some cases, heat cannot be applied uniformly. Further, when the surface of the lower mold 72 is provided with a concavo-convex shape, it is possible to give a high-class feeling aesthetically. In the present embodiment, instead of making the surface of the lower mold 72 uneven, the surface of the ultrasonic horn 52 that contacts the film W is knurled to form a mesh-like uneven shape over the entire surface. It may be formed. Even in this case, the same effect as when the surface of the lower mold 72 is made uneven can be obtained, and heat can be uniformly applied to the entire surface of the film W. In addition, when making the surface of the lower mold 72 or the surface of the ultrasonic horn 52 in contact with the film W uneven, other methods such as transfer and cutting can be used instead of knurling.

  In addition, the bag making machine by this Embodiment is not limited to an aspect as mentioned above, A various change can be added.

  For example, the ultrasonic welding mechanism for performing preheating on the two-layered strip-shaped film W in an overlapped state is not limited to the configuration shown in FIGS. 2 to 4. As long as it can preheat by ultrasonic welding to the two-layered strip-like film W in an overlapped state, the ultrasonic welding mechanism has a configuration other than that shown in FIGS. May be adopted. In particular, there are various variations in the shape of the ultrasonic horn, and it is not limited to the shape of the ultrasonic horn 52 as shown in FIG.

  In addition, the heat seal part for performing the final heat seal on the two-layer belt-like film W that has been preheated by ultrasonic welding is not limited to the heat seal plate 42 as shown in FIG. . Any material other than the heat seal plate 42 may be adopted as the heat seal portion as long as the heat seal of the finish can be performed on the two-layer belt-shaped film W preheated by ultrasonic welding. .

  In the above description, in the horizontal seal portion 40, the ultrasonic welding mechanism 50 for performing preheating on the two-layer belt-like film W by ultrasonic welding is installed. Although the embodiment in which preheating is performed by ultrasonic welding along the width direction of the two-layered strip-shaped film W in the combined state has been described, such a feature of the present invention is described. The present invention can also be applied to the vertical seal portion 30 that seals both side edges of the film W. That is, an ultrasonic welding mechanism is installed on the upstream side of the heat seal plate 32 in the conveying direction of the film W in the vertical seal portion 30, and the two-layer belt-like shape in an overlapped state is provided by such an ultrasonic welding mechanism. The film W is preheated by ultrasonic welding at both side edges thereof, and then the heat-seal plate 32 is used to heat-finish the two-layer belt-shaped film W that has been preheated at both side edges. You may make it perform.

DESCRIPTION OF SYMBOLS 10 Paper feed roll 12 Turn bar 14 Center blade 16 M-shaped board 20 1st nip roll 22 Dancer roll 24 2nd nip roll 26 3rd nip roll 28 4th nip roll 29 Guide roll 30 Vertical seal part 32 Heat seal plate 34 Cooling plate 40 Horizontal seal portion 42 Heat seal plate 44 Cooling plate 46 Cutting blade 50 Ultrasonic welding mechanism 52 Ultrasonic horn 54 Vibrator portion 55 Oscillator 56 Air cylinder 58 Push air supply line 60 Pull air supply line 62 Push air supply portion 64 Pulling air supply unit 66 LM guide 68 Damper 70 Lower plate 72 Lower mold 74 Support frame 80 Mark sensor 82 Mark sensor W Film W 'Bag

Claims (7)

A transport unit that transports a plurality of strip-shaped films along the longitudinal direction of the film,
An ultrasonic welding part that performs preheating by ultrasonic welding on a plurality of strip-shaped films that are transported by the transport part,
A heat seal part for performing a heat seal on the plurality of strip-shaped films preheated by the ultrasonic welding part;
A bag making machine.   The ultrasonic welding part includes an ultrasonic horn, a vibrator part that gives vibration energy to the ultrasonic horn, and a receiving part that receives the ultrasonic horn, and a plurality of strip-like shapes in an overlapped state. The thermoplastic resin layer of each film is welded by ultrasonic vibration of the ultrasonic horn in a state where the film is pushed by the ultrasonic horn and received by the receiving portion. The bag making machine described.   The bag making machine according to claim 2, wherein a surface of the ultrasonic horn in contact with the film or a surface of the receiving portion has an uneven shape.   The bag making machine according to claim 3, wherein the uneven shape is provided by knurling. The ultrasonic welding part is adapted to perform preheating by ultrasonic welding along the width direction with respect to a plurality of strip-shaped films in an overlapped state,
5. The heat seal portion according to claim 1, wherein finishing heat sealing is performed along a width direction of the plurality of strip-shaped films preheated by the ultrasonic welding portion. The bag making machine according to claim 1. The ultrasonic welding portion is adapted to perform preheating by ultrasonic welding at both side edges of a plurality of strip-shaped films in an overlapped state,
5. The heat seal part according to claim 1, wherein finishing heat sealing is performed at both side edges of the plurality of strip-shaped films preheated by the ultrasonic welding part. The bag making machine according to one item. A step of transporting a plurality of strip-shaped films along the longitudinal direction of the films in a superimposed state;
A step of performing preheating by ultrasonic welding on a plurality of strip-shaped films in an overlaid state;
A step of heat-sealing a plurality of strip-shaped films that have been preheated by ultrasonic welding; and
A bag making method comprising:

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