Side-fold bag sealing and cutting device.

Abstract

Invention details;

Description

Gusset bag sealing and cutting device

[0001] The present invention relates to a sealing and cutting device for gusseted bags.

[0002] Various devices have been developed for sealing the opening of a packaging bag formed from a tubular film after it has been filled with absorbent products such as sanitary napkins or disposable diapers. For example, the sealing and cutting device disclosed in Patent Document 1 has a heating element for sealing by welding, a presser foot for holding the film, a blade for cutting the film, and another presser foot provided above the supplied film in that order along the film supply direction, and a receiving element provided below the film against which the presser foot and heating element are pressed via the film. That is, this sealing and cutting device sandwiches and welds the film between the heating element and the receiving element, and lowers the blade to cut the film while sandwiching and holding the film between the presser foot and the receiving element on both sides of the blade.

[0003] Furthermore, the invention of Patent Document 2 is a device for sealing a packaging bag with a gusset (gusset bag), and includes a pair of upper and lower heat seal bars and a fusion blade attached via a heat insulating material to a notch formed at the tip of the upper heat seal bar. The bag is sandwiched between the upper heat seal bar and the fusion blade and the lower heat seal bar, and thermal welding and fusion cutting are performed simultaneously. Patent Document 2 also discloses a configuration in which the excess portion of the gusset bag is cut off with a cutting blade instead of a fusion blade. When using a cutting blade for gusset bags, a method of cutting while holding the bag in front of and behind the cutting blade, as in the invention of Patent Document 1, is also adopted. While these conventional inventions all seal bags by welding, the heater bars, such as heating elements and heat seal bars, used for this purpose generally include nichrome wire types and cartridge heater types.

[0004] Japanese Utility Model Application Publication No. 5-62410 Japanese Patent Application Publication No. 2004-238005

[0005] However, when the nichrome wire heater bar is used, the exposed nichrome wire must be covered with glass tape or the like, which poses several problems, including the need to frequently replace the glass tape, the need to remove melted glass tape that adheres to the heater bar and is time-consuming to remove, and the need to flatten the tip of the heater bar. In particular, in the case of gusseted bags, the folded portions on both sides in the width direction are thick and the central portion is thin. Therefore, if the tip of the heater bar is flat, it is difficult to adjust the gap between the top and bottom to zero across the entire width direction, which may result in poor sealing quality. Furthermore, some devices incorporate retractable glass tape to reduce the hassle of replacing the glass tape. However, this increases the distance between the heater bar and the cutting blade, which directly affects the length of the tab remaining at the end of the gusseted bag, which is undesirable from the standpoints of material conservation and aesthetics.

[0006] On the other hand, when using a cartridge heater system for the heater bar, there is no restriction on the tip of the heater bar being flat, but the equipment is larger and less flexible in positioning compared to the nichrome wire system because external cooling plates are attached before and after the heater bar for insulation, and heat pipes are incorporated to distribute heat evenly throughout the heater bar. As a result, for example, the distance between the heater bar and the cutting blade increases, resulting in a longer edge length remaining on the end of the gusseted bag. Furthermore, unlike the nichrome wire system, there is no exposed nichrome wire, so coatings such as glass tape can be used instead. However, if the tip of the heater bar is flat, melted film will adhere to the coating, forcing the use of glass tape or other similar materials, which ultimately has a negative impact on product productivity.

[0007] The present invention has been made in consideration of the above problems, and its object is to reduce the size of the device and improve product productivity while sealing gusseted bags using a cartridge heater system.

[0008] (Modes of the Invention) The following modes of the invention are examples of the configuration of the present invention, and are described by item to facilitate understanding of the various configurations of the present invention. Each item does not limit the technical scope of the present invention, and while taking into consideration the best mode for carrying out the invention, some of the components of each item may be replaced or deleted, or other components may be added, and these may also be included in the technical scope of the present invention.

[0009] (1) A gusset bag sealing and cutting device for forming a gusset bag seals an opening of a film filled with a product, and cuts off an excess portion of the film behind the sealed portion, with the opening direction of the opening being the front side and the product side being the front side, the device comprising: a pair of heater bars that move in a vertical direction approaching each other and sandwich and seal the opening of the film from above and below; a pair of film pressers that move in a vertical direction approaching each other at positions close to the rear side of the pair of heater bars and sandwich and press the film from above and below; a cutter that moves together with an upper film holder of a film holder and moves downward independently of the upper film holder to cut the film while the film is sandwiched between the pair of heater bars and the pair of film holders, wherein the pair of film holders sandwich the film at least on the rear side of the cutter, the pair of heater bars are constructed of cartridge heaters, and the tips that sandwich the film engage with each other and form a wavy shape along the side when viewed from the front in the front-to-rear direction.

[0010] The gusset bag sealing and cutting device described in this section is intended for gusset bags formed from film and filled with a product, and includes a pair of heater bars, a pair of film holders, and a cutter. The pair of heater bars perform the film sealing function, moving vertically toward each other and clamping the opening of the film from above and below to weld and seal the film. The pair of film holders move vertically toward each other and clamp the film from above and below to hold and secure the film for cutting. In this case, the pair of film holders are positioned in close proximity to the rear of the pair of heater bars, so that they press a position close to the sealed portion of the film sealed by the pair of heater bars. The pair of film holders are also configured to clamp the film at least behind the cutter.

[0011] The cutter, which performs the function of cutting the film, moves together with the upper film holder of the pair of film holders and cuts the film by moving downward independently of the upper film holder while the film is sandwiched between the pair of heater bars and the pair of film holders as described above. Here, the cutter, which moves together with the upper film holder, is positioned close to the film holder, so that it is close to the rear side of the pair of heater bars and cuts a position close to the sealed portion of the film sealed by the pair of heater bars. Moreover, because the pair of film holders sandwich the film at least on the rear side of the cutter, the cutter cuts the film between the portion of the film sandwiched between the pair of film holders and the portion of the film sandwiched between the pair of heater bars.

[0012] In the gusset bag sealing and cutting device described in this section, the pair of heater bars are configured as cartridge heaters, so there is no need to cover the unexposed nichrome wire with glass tape or the like, and there is no restriction on the shape of the heater bar tips being flat. Therefore, the tips of the pair of heater bars that sandwich the film are shaped like waves that run along the lateral direction when viewed from the front in the front-to-back direction, so that the pair of heater bars engage with each other. This increases the area that comes into contact with the film compared to when the tips are flat, and tension is applied to the film at the peaks of the waves at the heater bar tips, resulting in sealing at the peaks. Furthermore, wrinkles in the film are smoothed out, making it easier to apply pressure than when sealing with a flat surface.

[0013] This not only eliminates the need to adjust the gap above and below the heater bar, but also allows sealing to be performed at a lower temperature than conventional methods, resulting in stable sealing even without the need for a heat pipe. Furthermore, the lower temperature eliminates the need for the cooling plate on the film holder side of the external cooling plates that were previously attached before and after the heater bar. Therefore, despite the use of cartridge heaters in the heater bar, the device is smaller and more compact, allowing for greater freedom in positioning. In particular, eliminating the need for one cooling plate shortens the distance between the heater bar and the film holder, in other words, the distance between the heater bar and the cutter, thereby reducing the length of the tab remaining at the end of the gusseted bag.

[0014] Furthermore, because the tips of the pair of heater bars are wavy and cooler than conventional ones, melted film is less likely to adhere to them, even without the use of glass tape, etc. Therefore, the labor required to remove the adhered film is reduced, and the labor required to replace the glass tape, etc., and the labor required to remove the melted glass tape, etc. from the heater bars are eliminated, improving product productivity. Note that the terms "front-rear direction," "front side," and "rear side" used herein are used exemplarily to indicate the positional relationship of each element based on the opening direction of the film opening, and do not limit the actual orientation of the device or the flow direction of the product.

[0015] (2) In the above (1), the pair of heater bars have coated tips. In the gusset bag sealing and cutting device described in this section, the tips of the pair of heater bars that sandwich the film are coated, so that melted film does not adhere to them. This eliminates the need to remove the adhered film, further improving product productivity.

[0016] (3) In the device for sealing and cutting gusseted bags described in (1) and (2) above, the pair of film holders has a first holder portion that sandwiches the film in front of the cutter and a second holder portion that sandwiches the film behind the cutter. In the device for sealing and cutting gusseted bags described in this section, the pair of film holders that hold the film for cutting by the cutter have a first holder portion that sandwiches the film in front of the cutter and a second holder portion that sandwiches the film behind the cutter. Therefore, when cutting the film, the cutter, which moves with the upper film holder, moves downward while being housed between the first and second holder portions of the upper film holder. Then, with the first holding portions of the pair of upper and lower film holders sandwiching the film and the second holding portions of the pair of upper and lower film holders sandwiching the film, the cutter moves further downward independently from the upper film holder, descending to between the first and second holding portions of the lower film holder, thereby cutting the film. In this way, the film is held down on both the front and back sides, and the cutter cuts the space between them, ensuring consistent cutting quality.

[0017] (4) In the above (1) and (2), the pair of film holders clamp the film only behind the cutter. The gusset bag sealing and cutting device described in this section is configured so that the pair of film holders do not clamp the film in front of the cutter, but only behind the cutter. In other words, the pair of film holders do not have a portion that clamps the film between the cutter and the heater bar in the front-to-rear direction. This reduces the distance between the pair of heater bars and the cutter, thereby reducing the length of the tabs remaining at the end of the gusset bag. Furthermore, even if heat from the heater bar is transferred to the cutter because the cutter is closer to the heater bar, this is not considered to have any particular effect.

[0018] Furthermore, due to the above-described configuration, when cutting the film, the cutter moves downward together with the upper film holder, sandwiching the film between the pair of upper and lower heater bars, and then moves further downward independently of the upper film holder while the pair of upper and lower film holders are still sandwiching the film. The cutter then cuts the film held in place by the pair of heater bars and the pair of film holders. In this way, the pair of heater bars are not only used to seal the film, but also to hold the film together with the pair of film holders when cutting the film. At this time, the wave-shaped tips of the pair of heater bars that engage with each other stably hold the film in place. Therefore, despite the simplified structure of the pair of film holders, the film is cut by the cutter in a sufficiently taut state, maintaining the quality of the film cutting.

[0019] (5) In the above items (1) to (4), the pair of film holders have a tip of one film holder that forms a convex rib extending in the lateral direction, and a tip of the other film holder that forms a concave rib extending in the lateral direction. In the gusset bag sealing and cutting device described in this item, the tip of one of the pair of film holders forms a convex rib extending in the lateral direction, and the tip of the other film holder forms a concave rib extending in the lateral direction. Therefore, when the pair of film holders approach each other to sandwich the film, the tips of the pair of film holders engage with each other at the convex rib and the concave rib, thereby pulling the film, and the quality of cutting by the cutter performed in this state is more stable. Furthermore, the combination of convex and concave stripes extending laterally on a pair of film holders pulls the film uniformly across the entire width, so compared to, for example, a tip shape in which concave and convex stripes are repeatedly provided along the side, marks from the press are less likely to remain on the film, and the aesthetic appearance of the product is not marred.

[0020] (6) In the above-mentioned (5), the pair of film holders includes a gusset bag sealing and cutting device in which the tip of one film holder is formed of an elastic material and the other film holder is formed of a rigid material. In the gusset bag sealing and cutting device described in this item, the tip of one of the pair of film holders is formed of an elastic material that allows elastic deformation, and the other film holder is formed of a rigid material that suppresses elastic deformation. Therefore, for example, if the tip of the film holder having a convex tip shape is formed of an elastic material, the convex tip will be pressed against the concave tip of the film holder formed of a rigid material while elastically deforming, thereby stably pressing the film without gaps. Similarly, if the tip of the film holder having a concave tip shape is formed of an elastic material, the concave tip will be pressed against the convex tip of the film holder formed of a rigid material while elastically deforming, thereby also stably pressing the film without gaps. Furthermore, in either case, the protrusions and recesses are in close contact without directly depending on the depth of the recesses of the recesses, and by forming the recesses of the recesses to be shallow, excess slack in the film is avoided.

[0021] (7) The sealing and cutting device for gusseted bags according to (6) above, wherein the elastic member is silicone rubber and the rigid member is heat-resistant resin. In the sealing and cutting device for gusseted bags described in this section, the elastic member forming the tip of one film holder is silicone rubber, and the rigid member forming the other film holder is heat-resistant resin. As described in (1) above, if the cooling plate on the film holder side of the external cooling plates conventionally attached to the front and rear of the heater bar is eliminated, the heater bar and the film holder will be adjacent to each other. This makes it easier for heat to transfer to the film holder, but by making it out of silicone rubber or heat-resistant resin, it is less susceptible to the effects of heat.

[0022] (8) The sealing and cutting device for gusseted bags according to any one of items (1) to (7) above, wherein the tip blade of the cutter has a triangular wave shape along the lateral direction when viewed from the front, and the triangular wave shape is inclined slightly upward from the lateral center toward both sides in the lateral direction. In the sealing and cutting device for gusseted bags described in this item, the tip blade of the cutter has a triangular wave shape along the lateral direction when viewed from the front to back in the front-to-rear direction. In other words, it is a so-called serrated blade with multiple triangular blades. Furthermore, when viewed from the front, the triangular wave shape of the tip blade of the cutter is inclined slightly upward from the lateral center toward both sides in the lateral direction, so that the blade near the lateral center protrudes downward more than the blades near both sides in the lateral direction. This allows the cutter to gradually cut the film from near the center toward both sides in the width direction (lateral direction), resulting in a smooth cut without placing any unnecessary load on the film holders or heater bars that sandwich the film.

[0023] Because the present invention has the above-described configuration, it is possible to reduce the size of the device and improve product productivity while still sealing gusseted bags using a cartridge heater system.

[0024] 6A is a perspective view schematically illustrating an example of the configuration of a gusset bag sealing and cutting device according to an embodiment of the present invention. FIG. 6B is a side view of the gusset bag sealing and cutting device of FIG. 1. FIG. 6C shows a pair of heater bars of the gusset bag sealing and cutting device of FIG. 1 alone, with (a) being a front view and (b) being an enlarged view with the ends closed. FIG. 6D is a front view of a cutter of the gusset bag sealing and cutting device of FIG. 1 alone. FIG. 6E shows an image of a film being sealed by the gusset bag sealing and cutting device of FIG. 1 from a side view. FIG. 6F shows a film being cut by the gusset bag sealing and cutting device of FIG. 1, with (a) being an image view from a side view and (b) being an enlarged view of the vicinity of the cut point in (a). FIG. 6F shows another embodiment of the gusset bag sealing and cutting device according to an embodiment of the present invention, with an enlarged view corresponding to FIG. 6B.

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following describes an embodiment of the present invention with reference to the accompanying drawings. Detailed descriptions of parts identical or corresponding to those in the prior art will be omitted, and identical or corresponding parts will be designated by the same reference numerals throughout the drawings. Figures 1 and 2 show an example of the configuration of a gusseted bag sealing and cutting device 10 according to an embodiment of the present invention. Also shown in Figure 1 is a gusseted bag (a packaging bag with a gusset) W placed on a discharge conveyor 90 in an apparatus adjacent to the gusseted bag sealing and cutting device 10, with the top and both sides secured by a product upper presser 92 and a product side presser 94, and the surface on the far right side of the figure being held down by a stopper (not shown).

[0026] This gusseted bag W is in a state where one opening (located on the surface on the far right side in FIG. 1 ) of a tubular film F cut into individual bags has been closed in a pre-process leading up to the gusseted bag sealing and cutting device 10, and the product has been filled inside through the other opening. That is, the gusseted bag sealing and cutting device 10 of this embodiment targets the gusseted bag W in the state described above, seals the other opening of the film F, and cuts off any excess portion of the film F. Hereinafter, for convenience of explanation, the right side in FIG. 2 is referred to as the front-to-rear direction, the direction perpendicular to the plane of the paper in FIG. 2 is referred to as the lateral direction, and the up-to-down direction in FIG. 2 is referred to as the up-to-down direction. Note that FIG. 1 illustrates the gusseted bag W after the other (rear) opening has been sealed by the gusseted bag sealing and cutting device 10.

[0027] 1 and 2, a gusseted bag sealing and cutting device 10 according to an embodiment of the present invention includes a pair of upper and lower heater bars 12, 14, a pair of upper and lower film holders 30, 40, a cutter 50, cooling plates 60, 62, and a selvedge recovery nozzle 86. All of these components extend laterally to correspond to the width of the film F. The pair of upper and lower heater bars 12, 14 are used to heat and seal the film F while sandwiching it, as described below. Each of the heater bars 12, 14 is of a cartridge heater type including a cartridge heater 16, and in this embodiment, they have a tapered shape toward the opposing leading ends 12a, 14a when viewed from the side as shown in FIG. 2.

[0028] As shown in Fig. 3(a), the tips 12a, 14a of the pair of heater bars 12, 14 are corrugated along the lateral direction (the left-right direction in Fig. 3(a)), in other words, have a shape in which concaves and convexes are alternately provided along the lateral direction. These corrugated shapes are positioned such that, when the heater bars 12, 14 approach and collide with each other as described below, the tips 12a, 14a engage with each other, and the concaves and convexes mesh with each other, as shown in Fig. 3(b). Furthermore, at least the area of ​​the pair of heater bars 12, 14 that includes the tips 12a, 14a is coated with a coating material, such as a fluorine-based resin.

[0029] 1 and 2 , the pair of upper and lower film holders 30, 40 sandwich and hold down the film F as described below, and are adjacent to the rear sides of the pair of heater bars 12, 14 with their tips facing each other. Referring to FIG. 5 , the pair of film holders 30, 40 of this embodiment each include a first holding portion 32, 42 and a second holding portion 34, 44. More specifically, the upper film holder 30 includes the first holding portion 32 located on the rear side (left side in FIG. 5 ) of the upper heater bar 12 and the second holding portion 34 located rearward of the first holding portion 32, with a cutter 50 housed between them. The lower film holder 40 includes the first holding portion 42 located rearward of the lower heater bar 14 and the second holding portion 44 located rearward of the first holding portion 42, with a space provided between them.

[0030] In the upper film holder 30, portions including the tip 32a of the first holding portion 32 and the tip 34a of the second holding portion 34 are formed of an elastic material that allows elastic deformation, which in this embodiment is silicone rubber, and other portions are formed of a heat-resistant resin or the like. Furthermore, the lower film holder 40 is substantially entirely formed of a rigid material that suppresses elastic deformation, which in this embodiment is heat-resistant resin. Furthermore, in the pair of film holders 30, 40 of this embodiment, as shown in FIG. 6( b), the tip 32a of the first holding portion 32 and the tip 34a of the second holding portion 34 of the upper film holder 30 form a convex rib extending laterally (a direction perpendicular to the plane of the paper in FIG. 6( b)), and the tip 42a of the first holding portion 42 and the tip 44a of the second holding portion 44 of the lower film holder 40 form a concave rib extending laterally. That is, the tips 32a, 34a of the upper film holder 30 have convex portions that taper downward in side view as shown in Fig. 6(b), and are uniformly provided along the lateral direction. Furthermore, the tips 42a, 44a of the lower film holder 40 have concave portions that are recessed downward in side view as shown in Fig. 6(b), and are uniformly provided along the lateral direction.

[0031] As described above, the cutter 50 is housed between the first and second pressing portions 32 and 34 of the upper film presser 30. In this embodiment, the cutter 50 has a shape as shown in FIG. 4 when viewed from the front. That is, the cutter 50 has a tip blade 50a, known as a serrated blade, that forms a triangular wave shape along the lateral direction (the left-right direction in FIG. 4 ). The tip blade 50a includes multiple triangular blades 52, and the tip blade 50a is housed between the first and second pressing portions 32 and 34 with the tip blade 50a facing downward. The triangular wave shape of the tip blade 50a is slightly inclined upward from the lateral center C of the cutter 50 toward both sides in the lateral direction. As a result, the positions of the multiple triangular blades 52 are gradually shifted upward from the lateral center C toward both sides in the lateral direction. In this embodiment, although not limited thereto, the inclination angle R of the triangular wave shape of the tip blade 50a relative to the lateral direction is approximately 2°.

[0032] 2 and 5, the cooling plates 60, 62 are provided to suppress heat transfer from the pair of heater bars 12, 14 to the film F forming the gusseted bag W, with the cooling plate 60 being provided in front of the upper heater bar 12 and the cooling plate 62 being provided in front of the lower heater bar 14. These cooling plates 60, 62 are configured, for example, so that air passing through flow paths provided therein is blown out from the tip of the upper cooling plate 60 facing downward and left in the figure and the tip of the lower cooling plate 62 facing upward and left in the figure. In addition, a selvedge recovery nozzle 86 is provided adjacent to the rear side of the lower film holder 40, and as described below, the excess portion of the film F cut by the cutter 50 is sucked in through an opening facing upward and discharged through a discharge duct 88.

[0033] 1 and 2, the upper heater bar 12, upper film holder 30, and cooling plate 60 are fixed directly or indirectly to a cross beam 64, while the lower heater bar 14, lower film holder 40, cooling plate 62, and selvedge recovery nozzle 86 are fixed directly or indirectly to a cross beam 66. These cross beams 64, 66 are mounted on posts 70, 72 erected on both sides, via sliders 74, 76, so that they can move up and down. Connecting portions 78, 80 are fixed to the sliders 74, 76, respectively, and one end of a drive rod (not shown) is connected to these connecting portions 78, 80 by a pin. The drive rod connected to the connecting portion 78 and the drive rod connected to the connecting portion 80 are driven by a drive member (not shown) to move up and down in opposite directions. Then, when the cross beam 64 descends, the cross beam 66 ascends, causing the upper heater bar 12 and the lower heater bar 14 to move closer to each other and collide, and also causing the upper film holder 30 and the lower film holder 40 to move closer to each other. Also, when the cross beam 64 ascends, the cross beam 66 descends, causing the upper heater bar 12 and the lower heater bar 14 to move away from each other, and also causing the upper film holder 30 and the lower film holder 40 to move away from each other.

[0034] When the cross beam 64 moves up and down, the cooling plate 60 and the cutter 50 housed in the upper film presser 30 move up and down together with the upper heater bar 12 and film presser 30. Furthermore, a driving mechanism such as a cylinder is attached to the cross beam 64, and these driving mechanisms move the upper film presser 30 up and down independently of the cross beam 64, and further move the cutter 50 up and down independently of the upper film presser 30. On the other hand, when the cross beam 66 moves up and down, the cooling plate 62 and selvage recovery nozzle 86 move up and down together with the lower heater bar 14 and film presser 40.

[0035] Next, the operation of the gusseted bag sealing and cutting device 10 according to an embodiment of the present invention when the opening of the film F forming the gusseted bag W is sealed and the excess portion is cut off will be described. First, as shown in Figures 1 and 2, with the cross beam 64 raised and the cross beam 66 lowered, the gusseted bag W is placed on the discharge conveyor 90 with the front opening closed and the product filled in through the rear opening. The gusseted bag W is then held down by the upper product presser 92, the side product presser 94, and a stopper (not shown). The drive rod connected to the connecting portion 78 moves downward and the drive rod connected to the connecting portion 80 moves upward, causing the cross beam 64 to begin to descend and the cross beam 66 to begin to ascend. At approximately the same time, a pair of gusset members (not shown) begin to move laterally toward each other toward either side of the rear opening of the gusseted bag W.

[0036] As a result of the above-described operation, both sides of the opening of the gusseted bag W are folded inward by the pair of gusset members, while the opening of the gusseted bag W is closed by the pair of upper and lower heater bars 12, 14 and the pair of upper and lower film holders 30, 40 which are approaching each other. Then, as shown in Fig. 5, the portion of the film F whose opening has been closed is sandwiched and sealed by the pair of upper and lower heater bars 12, 14. At this time, the pair of heater bars 12, 14 have tips 12a, 14a which are wavy in shape along the lateral direction and interlock with each other, as shown in Fig. 3(a), so that when the tips 12a, 14a engage with each other as shown in Fig. 3(b), the film F is sandwiched between the peaks 20 of the convex portions of the wavy shapes and the valley bottoms 22 of the concave portions while applying tension to the film F.

[0037] Furthermore, as shown in FIG. 6 , the drive mechanism on the cross beam 64 lowers the upper film holder 30 independently of the cross beam 64, whereby the rear side of the sealed portion of the film F sealed by the heater bars 12, 14 is sandwiched between the first and second holding portions 32, 34 of the upper film holder 30 and the first and second holding portions 42, 44 of the lower film holder 40. At this time, as shown in FIG. 6( b), the tip ends 32a, 34a of the first and second holding portions 32, 34, which are made of silicone rubber, an elastic member, and which form convex stripes extending in the lateral direction, are pressed into the tip ends 42a, 44a of the first and second holding portions 42, 44, which are made of heat-resistant resin, a rigid member, and which form concave stripes extending in the lateral direction. Then, the film F is sandwiched between them under tension.

[0038] Next, the drive mechanism on the cross beam 64 lowers the cutter 50, which was housed between the first and second holding portions 32 and 34 of the upper film holder 30, into the space between the first and second holding portions 42 and 44 of the lower film holder 40, thereby cutting the film F. When the cutter 50 is then housed and the upper film holder 30 rises, the excess portion of the film F that was sandwiched between the upper and lower second holding portions 34 and 44, located rearward of the portion cut by the cutter 50, is released and sucked by the edge recovery nozzle 86 and discharged through the discharge duct 88. Furthermore, the drive rod connected to the connecting portion 78 moves upward and the drive rod connected to the connecting portion 80 moves downward, causing the cross beam 64 to rise and the cross beam 66 to descend, moving to the positions shown in FIGS. 1 and 2 . This completes the sealing and cutting operation of the film F to form the gusseted bag W by the gusseted bag sealing and cutting device 10.

[0039] Here, the gusset bag sealing and cutting device 10 according to the embodiment of the present invention can take a form in which the pair of film holders 30, 40 do not have the first holding portions 32, 42. In this case, as shown in Figure 7, for example, the film F is sandwiched and sealed by the pair of heater bars 12, 14, and the film F is cut with the pair of heater bars 12, 14 and the second holding portions 34, 44 of the pair of film holders 30, 40 sandwiching the film F before and after the cutter 50.

[0040] Furthermore, the gusset bag sealing and cutting device 10 according to the embodiment of the present invention is not limited to the configuration shown in Figures 1 to 7 and may have other configurations. For example, the shape of the tips 12a, 14a of the pair of heater bars 12, 14 is not limited to the shape shown in Figure 3(b), as long as they are wavy shapes that engage with each other in the lateral direction. They may also have shapes such as triangular waves, rectangular waves, or sinusoidal waves. Furthermore, the tips 32a, 34a of the film holder 30 may be formed of an elastic material other than silicone rubber, and the film holder 40 may be formed of a rigid material other than heat-resistant resin. Furthermore, the tips 32a, 34a of the upper film holder 30 may have concave ridges extending laterally, and the tips 42a, 44a of the lower film holder 40 may have convex ridges extending laterally. Furthermore, the cutter 50 is not limited to the shape shown in Figure 4, and for example, the triangular wave shape of the tip blade 50a may be slightly inclined upward from one lateral end of the cutter 50 to the other lateral end.

[0041] According to the embodiment of the present invention configured as described above, the following effects can be obtained. That is, as shown in Figures 1 and 2, the gusseted bag sealing and cutting device 10 according to the embodiment of the present invention includes a pair of heater bars 12, 14 that sandwich the film F from above and below to weld and seal the film F, a pair of film holders 30, 40 that sandwich the film F from above and below to hold and fix the film F for cutting, and a cutter 50. The cutter 50 moves together with the upper film holder 30, and cuts the film F by moving downward independently from the upper film holder 30 while the film F is sandwiched between the pair of heater bars 12, 14 and the pair of film holders 30, 40.

[0042] In the gusset bag sealing and cutting device 10 according to the embodiment of the present invention, the pair of heater bars 12, 14 are configured with cartridge heaters 16, so there is no need to cover the unexposed nichrome wire with glass tape or the like, and there is no restriction that the tips of the heater bars 12, 14 must be flat. Therefore, as shown in FIG. 3, the tips 12a, 14a of the pair of heater bars 12, 14 that sandwich the film F are shaped like waves extending in the lateral direction so that the pair of heater bars 12, 14 engage with each other. This allows for a larger contact area with the film F than when the tips are flat, and allows tension to be applied to the film F at the peaks 20 of the waves of the tips 12a, 14a, resulting in sealing at the peaks 20. Furthermore, wrinkles in the film F can be smoothed out, making it easier to apply pressure than when sealing with a flat surface.

[0043] This not only eliminates the need to adjust the gap between the heater bars 12 and 14, but also allows sealing at a lower temperature than conventional methods, enabling stable sealing without incorporating a heat pipe. Furthermore, the lower temperature than conventional methods eliminates the need for external cooling plates, which were previously attached to the front and rear of the heater bars 12 and 14, on the film holders 30 and 40 side. Therefore, despite the use of cartridge heaters 16 in the heater bars 12 and 14, the size of the device 10 can be reduced and made compact, increasing the flexibility of positioning. In particular, by eliminating the need for one cooling plate, the distance between the heater bars 12 and 14 and the film holders 30 and 40, in other words, the distance between the heater bars 12 and 14 and the cutter 50, can be reduced, thereby reducing the length of the tabs remaining at the end of the gusseted bag W. Furthermore, because the tips 12a and 14a of the pair of heater bars 12 and 14 are wavy and cooler than conventional methods, they are coated without the need for glass tape or the like, preventing the melted film F from adhering to them. Therefore, there is no need to take the time to remove the attached film F, the time to replace the glass tape, etc., or the time to remove the melted glass tape, etc. from the heater bars 12, 14, and it is possible to improve the productivity of the product.

[0044] 5 and 6, the gusset bag sealing and cutting device 10 according to the embodiment of the present invention has a pair of film holders 30, 40 that hold down the film F for cutting by the cutter 50, each having a first holding portion 32, 42 that sandwiches the film F in front of the cutter 50, and a second holding portion 34, 44 that sandwiches the film F behind the cutter 50. Therefore, when cutting the film F, the cutter 50, which moves together with the upper film holder 30, moves downward while being housed between the first holding portion 32 and the second holding portion 34 of the upper film holder 30. Then, with the first holding portions 32, 42 of the pair of upper and lower film holders 30, 40 sandwiching the film F and the second holding portions 34, 44 of the pair of upper and lower film holders 30, 40 sandwiching the film F, the cutter 50 moves further downward independently from the upper film holder 30, and descends to between the first holding portion 42 and the second holding portion 44 of the lower film holder 40, thereby cutting the film F with the cutter 50. In this way, since the film F is held down on both the front and rear sides and cut between them by the cutter 50, the quality of the cut can be stabilized.

[0045] 5 and 6, in this embodiment, the tip 32a of the first pressing portion 32 and the tip 34a of the second pressing portion 34 of the upper film presser 30 form a convex ridge extending laterally, and the tip 42a of the first pressing portion 42 and the tip 44a of the second pressing portion 44 of the lower film presser 40 form a concave ridge extending laterally. Therefore, when the pair of film pressers 30, 40 approach each other and sandwich the film F, the first pressing portions 32, 42 and the second pressing portions 34, 44 interlock with each other at the convex ridge and concave ridge, thereby pulling the film F, and therefore the quality of cutting by the cutter 50 performed in this state can be made more stable.

[0046] Furthermore, the combination of the convex and concave stripes extending laterally on the pair of film holders 30, 40 pulls the entire width of the film F uniformly, so compared to, for example, a tip shape with repeated concave and convex stripes along the side, it is less likely to leave marks on the film F. Therefore, it can be used particularly effectively in the first holders 32, 42 that clamp the area that remains as a selvedge after cutting by the cutter 50.

[0047] Furthermore, in the gusset bag sealing and cutting device 10 according to an embodiment of the present invention, the leading end 32a of the first pressing portion 32 and the leading end 34a of the second pressing portion 34 of the upper film pressing member 30 are formed from an elastic material that allows elastic deformation, while the first pressing portion 42 and the second pressing portion 44 of the lower film pressing member 40 are formed from a rigid material that suppresses elastic deformation. Therefore, when the upper and lower film pressing members 30, 40 collide, the leading ends 32a, 34a of the convex strips of the first pressing portion 32 and the second pressing portion 34 are pressed against the leading ends 42a, 44a of the concave strips of the first pressing portion 42 and the second pressing portion 44, which are formed from a rigid material, while elastically deforming, thereby enabling the film F to be stably pressed without any gaps. Furthermore, because the convex strips and the concave strips are in close contact without directly depending on the depth of the concave strips, excessive slack in the film F can be avoided by forming the concave strips shallow.

[0048] Furthermore, silicone rubber is used as the elastic member forming the tip 32a of the first pressing portion 32 and the tip 34a of the second pressing portion 34 of the upper film presser 30, and heat-resistant resin is used as the rigid member forming the first pressing portion 42 and the second pressing portion 44 of the lower film presser 40. Here, as mentioned above, of the external cooling plates that were conventionally attached to the front and rear of the heater bars 12, 14, if the cooling plate on the film presser 30, 40 side is eliminated, the heater bars 12, 14 and the film pressers 30, 40 will be adjacent to each other, as can be seen in Figures 5 and 6. For this reason, heat is particularly likely to transfer to the first pressing portions 32, 42 that are close to the heater bars 12, 14, but by forming them from silicone rubber or heat-resistant resin, they can be made less susceptible to the effects of heat.

[0049] Furthermore, in the gusset bag sealing and cutting device 10 according to the embodiment of the present invention, when viewed from the front in the front-rear direction as shown in Fig. 4, the tip blade 50a of the cutter 50 has a triangular wave shape that runs along the lateral direction, in other words, a so-called serrated blade having multiple triangular blades 52. Furthermore, when viewed from the front in Fig. 4, the triangular wave shape of the tip blade 50a of the cutter 50 is inclined slightly upward from the lateral center C toward both sides in the lateral direction, so that the blade 52 near the lateral center protrudes downward more than the blades 52 near both sides in the lateral direction. As a result, the film F is gradually cut by the cutter 50 from near the center toward both sides in the width direction (lateral direction), allowing for smooth cutting without applying excessive load to the film holders 30, 40 and heater bars 12, 14 that sandwich the film F.

[0050] On the other hand, the gusseted bag sealing and cutting device 10 according to the embodiment of the present invention may be configured so that the pair of film holders 30, 40 do not sandwich the film F in front of the cutter 50, but only sandwich the film F behind the cutter 50, as shown in Figure 7. In other words, the pair of film holders 30, 40 do not need to have first holder portions 32, 42 that press the film F between the cutter 50 and the heater bars 12, 14 in the front-to-rear direction. This allows the distance between the pair of heater bars 12, 14 and the cutter 50 to be made shorter, thereby making it possible to reduce the length of the selvedge remaining at the end of the gusseted bag W.

[0051] Furthermore, due to the above-described configuration, when cutting the film F, the cutter 50 cuts the film F held in place by the pair of heater bars 12, 14 and the pair of film holders 30, 40. That is, the pair of heater bars 12, 14 are used not only to seal the film F but also to hold the film F together with the pair of film holders 30, 40 when cutting the film F. At this time, the corrugated shape of the tips 12a, 14a of the pair of heater bars 12, 14 that engage with each other, as shown in FIG. 3, allows the film F to be stably held in place. Therefore, despite the simplified structure of the pair of film holders 30, 40, the film F can be cut by the cutter 50 in a sufficiently taut state, thereby maintaining the quality of the cutting of the film F. Moreover, the portion of the film F sandwiched between the pair of film holders 30, 40 is discarded as an excess portion after cutting by the cutter 50, so it is not a problem if marks or holes are formed there. Therefore, the pair of film holders 30, 40 are not limited to the tip shape shown in FIG. 7, and any tip shape that can more reliably fix the film F can be adopted.

[0052] 10: Gusset bag sealing and cutting device, 12, 14: Pair of heater bars, 12a, 14a: Tips of heater bars, 16: Cartridge heater, 30, 40: Pair of film holders, 32, 42: First holder section, 32a, 42a: Tips of first holder section, 34, 44: Second holder section, 34a, 44a: Tips of second holder section, 50: Cutter, 50a: Tip blade, F: Film, W: Gusset bag

Claims

1. The side-fold bag sealing and cutting device seals the opening of the film to create a side-fold bag. The film, which has been filled with the product, is trimmed, and the excess is placed on the side positioned rearward relative to the sealed portion of the film. The side on which the product is placed is considered the front when determining the front-back orientation of the film. The device is further assembled with a pair of heating strips that move up and down in an approaching manner to clamp and seal the film opening vertically; a pair of film clamps that move up and down in an approaching manner, positioned adjacent to the pair of heating strips on the back to clamp vertically and press the film; and a cutter that moves together with the upper film clamp of the pair of film clamps and moves downward independently from the upper film clamp, in a condition where the film is clamped between the pair of heating strips and the pair of film clamps to cut the film.Where a pair of film clamps are pressed onto the film at least on the back of the cutter and a pair of heating strips are arranged from cartridge heaters and the ends which are pressed onto the film are formed in a wave shape in the transverse direction in the front view in the front-back direction, allowing the pair of heating strips to be coordinated with each other.

2. Side-fold bag sealing and cutting device according to claim 1, where a pair of heating strips have coated ends.

3. Side-fold bag sealing and cutting device according to claim 1 or 2, where a pair of film clamps has a first clamping part that presses onto the film on the front of the cutter and a second clamping part that presses onto the film on the back of the cutter.

4. Side-fold bag sealing and cutting device according to claim 1 or 2, where a pair of film clamps are pressed onto the film just on the back of the cutter.

5. Side-fold bag sealing and cutting device according to any one of claims 1 through 4.Where the end of one pair of film clamps creates a long, protruding strip that expands in the transverse direction, and the end of the remaining film clamp creates a long, concave strip that expands in the transverse direction.

6. Side-fold bag sealing and cutting device according to claim 5, where the end of one pair of film clamps is constructed from a flexible part and the remaining film clamp is constructed from a rigid part.

7. Side-fold bag sealing and cutting device according to claim 6, where the flexible part is silicone rubber and the rigid part is heat-resistant resin.

8. Side-fold bag sealing and cutting device according to any one of claims 1 through 7, where the cutting blade at the end has a triangular wave shape along the transverse direction in the front view, a triangular wave shape that is slightly slanted upwards from the transverse center towards both transverse sides;