bag making machine

Abstract

To provide a bag making machine in which a pouch portion can be reliably separated from an unnecessary portion, productivity can be improved and manufacturing cost can be reduced by suppressing the decrease in the life of a Thomson blade, and a standing type pouch container can be manufactured without causing a deterioration in the open-bottom property.SOLUTION: In a pouch making machine of the invention that punches out three sides of the periphery of a pouch portion 12 formed on a film material 11 with a Thomson blade 31 so that a micro-connected portion 13 is formed, and then pulls an unnecessary portion 15 in a direction that intersects the film material transport direction and pulls the pouch portion 12 in the film material transport direction by a separation mechanism 50 to separate the micro-connected portion 13 and separates the pouch portion 12 from the unnecessary portion 15 to produce a pouch container P, the separation mechanism 50 comprises a nip-roll mechanism, wherein the outer circumference of a roller body 53 forming a roller surface 56 of one roller 51 is configured to have a shape that makes linear contact with the film material 11 along the film material transport direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a bag-making machine that produces pouch containers by using a Thomson blade to punch out the periphery of a pouch portion formed into a bag shape by heat-sealing predetermined positions of a resin film material, and then tearing the pouch portion to separate it from unnecessary portions. [Background technology]

[0002] Pouch containers formed into a bag shape by heat-sealing a resin film are widely used as packaging containers for various fluid contents such as daily necessities and food products, and stand-up pouch containers that are self-supporting are also widely known.

[0003] Various types of bag making machines have been proposed for producing such pouch containers. For example, Patent Document 1 discloses a bag making machine that produces pouch containers by sealing a predetermined area of ​​a film material being conveyed to form a bag-shaped pouch portion, punching it out with a Thomson blade so that a minute connecting portion is formed connecting the pouch portion to an unnecessary portion, and then nipping and pulling the pouch portion with a nip roll mechanism to tear off the minute connecting portion and separate the pouch portion from the unnecessary portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-160780 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, when punching out the entire periphery of the standing pouch portion, the bottom edge of the pouch portion needs to be cut with a Thomson blade through four films: two front and back films and a bottom film folded back and sandwiched between them. If the Thomson blade becomes dull, the bottom of the pouch portion may be welded together, reducing the bottom-opening ability (self-standing ability) required for a standing pouch container. Furthermore, because four sheets of film must be punched, the durability of the Thomson blade is likely to decrease, such as the blade becoming dull, resulting in problems such as reduced productivity and the need to frequently replace the Thomson blade, which leads to increased costs.

[0006] To address this problem, it is conceivable to punch out three sides of the periphery of the pouch, excluding the bottom edge. In this case, the punching process results in the creation of an unnecessary portion that includes a strip-shaped base portion that continues in the film material conveyance direction and strip-shaped branch portions that are connected to the base portion at one end located on the opening side of the pouch and extend in the width direction of the film material. However, since the other end of the branch portion located on the bottom side of the pouch portion is discontinuous, when the pouch portion is separated from the unnecessary portion by pinching and pulling the pouch portion with a nip roll mechanism, the shear force caused by the difference in tensile force acting on one end side and the other end side of the branch portion causes the branch portion itself to be cut rather than being cut at the micro-connecting portion, resulting in the problem that part of the branch portion remains in the pouch portion. Furthermore, because the pouch portion is torn off and separated from the unnecessary portion, the branch portion may jump up and get caught in the nip roll mechanism. At this time, when the unnecessary portion is wound up by the winding mechanism, the branch portion may be torn off and attached to the pouch portion or transported together with the pouch portion, which is a problem.

[0007] The present invention has been made in light of the above circumstances, and its object is to provide a bag making machine that can reliably separate the pouch portion from the unnecessary portion, suppress a decrease in the lifespan of the Thomson blade, thereby improving productivity and reducing manufacturing costs. Another object of the present invention is to provide a bag making machine capable of producing standing pouch containers that do not lose their bottom-opening properties due to punching and that exhibit their original function of being able to stand on their own. [Means for solving the problem]

[0008] The bag making machine of the present invention comprises an intermittent feed mechanism that intermittently feeds in a horizontal direction a resin film material that has been formed so that pouch portions formed in a bag shape are continuous at predetermined intervals; a punching device that punches out three sides of the peripheral edge of the pouch portion with a Thomson blade each time the film material is intermittently fed, so that an unnecessary portion remains so that a continuous state in the film material conveyance direction is maintained and a minute connecting portion connected to the unnecessary portion is formed; a winding mechanism that winds up the unnecessary portion of the film material so that the unnecessary portion is pulled in a direction intersecting the film material conveyance direction at a separation position where the pouch portion is separated from the film material; and a separation mechanism that is arranged downstream in the film material conveyance direction from the separation position and pulls the pouch portion in the film material conveyance direction to cut the minute connecting portion and separate it from the unnecessary portion, the separation mechanism comprising a pair of rollers that sandwich the film material from one side and the other side, one of the pair of rollers The rollers are configured to be driven to rotate, and the one roller The film conveying device includes a drive shaft extending in a direction perpendicular to the film conveying direction in a horizontal plane, and a plurality of roller bodies provided at predetermined intervals in the axial direction of the drive shaft, and the outer circumferential surfaces of the roller bodies are shaped to make line contact with the film along the film conveying direction. The outer circumferential surface of the roller body is configured as a curved surface in which the outer diameter is greatest at the center in the axial direction of the drive shaft and gradually decreases toward both ends in a cross section along the axis of the drive shaft. This solves the above problem. [Effects of the Invention]

[0009] According to the invention of claim 1, the punching device is configured to punch three sides of the periphery of the pouch portion with a Thomson blade, so even if the pouch portion is a standing type, there is no need to cut the bottom edge, and the thickness of the film to be cut can be small, making it possible to prevent a decrease in the durability of the Thomson blade.This makes it possible to improve productivity and reduce the frequency of Thomson blade replacement, thereby reducing manufacturing costs. Furthermore, the roller bodies constituting the nip portion where the pair of rollers abut against each other make linear contact with the pouch portion along the film conveyance direction, thereby reducing the dynamic frictional resistance of the roller bodies relative to the pouch portion, allowing the roller bodies to roll without sliding against the pouch portion at the nip portion. This prevents the branch portion from being severed by shear forces resulting from the difference in tensile forces acting on one end of the branch portion of the unnecessary portion that connects to the strip-shaped base portion that continues in the film conveyance direction and the other end that is discontinuous from the remaining unnecessary portion. This allows the pouch portion to be reliably separated from the unnecessary portion by severing the minute connecting portions. Furthermore, even if the branch portion is sandwiched between the pair of rollers, the frictional conditions at the nip portion ensure that the branch portion is returned to the base portion where it is wound by the winding mechanism. This prevents the branch portion from being torn off, preventing the unnecessary portion from being transported together with the pouch portion.

[0010] According to the present invention, By making the outer surface of the roller body a curved surface in a cross section along the axis of the drive shaft, with the outer diameter being greatest at the center of the axis of the drive shaft and gradually decreasing toward both ends, it becomes possible to easily achieve the desired friction state in the nip portion. Invention according to claim 2 According to the present invention, by increasing the hardness of the roller body, it is possible to further reduce the dynamic friction resistance of the roller body against the pouch portion, and it is possible to more reliably separate the pouch portion from the unnecessary portion. The invention according to claim 3According to the method, even if the sharpness of the Thomson blade decreases, the bottom of the pouch portion does not weld and the bottom opening ability is not impaired, so the resulting pouch container can reliably exhibit its original function as a standing type, that is, self-standing, and is extremely useful when manufacturing standing type pouch containers. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view schematically illustrating the configuration of an example of a bag making machine of the present invention. [Figure 2] FIG. 10 is a plan view schematically showing a film material in a state where punching lines have been formed by a punching device. [Figure 3] FIG. 2 is a perspective view schematically illustrating a configuration of a separation unit. [Figure 4] 10 is a schematic front view showing the main configuration of the separation mechanism as viewed from the film material conveyance direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] As shown in FIG. 1, the bag making machine 10 of this embodiment includes an intermittent feed mechanism 20 that intermittently feeds a strip of resin film material 11 in the horizontal direction, a punching device 30 that punches out pouch portions 12 formed into bags from the film material 11 at each intermittent feed, a winding mechanism 40 that winds up unnecessary portions 15 of the film material 11 that remain after punching out the pouch portions 12, a separation mechanism 50 that separates the pouch portions 12 from the unnecessary portions 15 to obtain pouch containers P, and a pouch container conveying mechanism 60 that conveys the pouch containers P.

[0014] As shown in Figure 2, the film material 11 has pouch portions 12 formed into bag shapes by heat-sealing predetermined areas of the film material 11, and these pouch portions 12 are arranged at least at predetermined intervals in the film material conveyance direction. In this embodiment, the pouch portion 12 is of a standing type, and is configured so that two pouch containers P are simultaneously produced (two-pouch production) along the film material conveying direction, for example. line up The two pouch portions 12 are formed so that the open ends face each other and the bottoms are positioned on the side edges of the film material 11. And, The film material 11 is conveyed so that one side seal portion is at the front in the film material conveying direction.

[0015] The punching device 30 is a Thomson cut device, and is configured to punch three sides of the periphery of the pouch portion 12 with a Thomson blade 31 so that, each time the film material 11 is intermittently fed, unnecessary portions 15 are left so that a continuous state in the film material transport direction is maintained, and minute connecting portions 13 connected to the unnecessary portions 15 are formed.

[0016] In this embodiment, as shown in FIG. 2 , three edges of the pouch portion 12, excluding the bottom edge, are punched out by a punching device 30 to form a punching line L. This maintains a continuous unnecessary portion 15, including a strip-shaped base portion 16 extending in the film conveyance direction and a strip-shaped branch portion 17 extending in the film width direction, one end of which is connected to the base portion 16 and located on the opening side of the pouch portion 12. This eliminates the need to cut the bottom edge of the standing pouch portion 12, allowing for a smaller film thickness to be cut, thereby preventing a decrease in the durability of the Thomson blade 31. This not only improves productivity but also reduces the frequency of replacement of the Thomson blade 31, thereby reducing manufacturing costs. Furthermore, even if the sharpness of the Thomson blade 31 deteriorates, the bottom of the pouch portion 12 is not welded together, preventing loss of bottom-opening capability. Therefore, the resulting pouch container P can reliably exhibit its inherent self-standing function as a standing pouch container.

[0017] The minute connecting portions 13 are formed in, for example, three locations on the upstream edge of the pouch portion 12 in the film conveying direction, and in, for example, one location on the upstream portion of the opening edge of the pouch portion 12 in the film conveying direction. The width of the minute connecting portions 13 is, for example, about 0.2 mm. Note that the positions and number of the minute connecting portions 13 are not particularly limited as long as they are configured to allow the pouch portion 12 to be separated.

[0018] As also shown in Figure 3, the winding mechanism 40 is configured so that at the separation position S where the pouch portion 12 is separated from the unnecessary portion 15, the unnecessary portion 15 of the film material 11 is pulled in a direction intersecting the film material conveying direction.

[0019] As shown in Figure 4, the separation mechanism 50 is composed of a nip roll mechanism having one roller 51 that contacts one side of the film material 11 and another roller 58 that contacts the other side of the film material 11, and is configured so that one roller 51 is rotated. The separation mechanism 50 is positioned downstream in the film material conveying direction from the separation position S, and is configured to clamp the downstream end of the pouch portion 12 in the film material conveying direction between a pair of rollers, one roller 51 and the other roller 58, and pull it in the film material conveying direction, thereby tearing off the minute connecting portion 13, thereby separating the pouch portion 12 from the unnecessary portion 15.

[0020] One of the rollers 51, which contacts one side of the film material 11, has a drive shaft 52 extending in a horizontal plane in a direction perpendicular to the film material transport direction, and a plurality of roller bodies 53 arranged at predetermined intervals in the axial direction of the drive shaft 52. The other roller 58, which abuts against the other side of the film material 11, is a cylindrical metal member with both ends rotatably supported on a shaft, and is configured to abut against the roller surface 56 of one roller 51 to form a nip portion.

[0021] The roller body 53 of one roller 51 is composed of a metallic cylindrical core material 54 and an elastic layer 55 that is provided on the outer periphery of one end of the cylindrical core material 54 and forms a roller surface 56 that comes into contact with the film material 11.

[0022] The outer peripheral surface of roller body 53, specifically the outer peripheral surface of elastic layer 55 forming roller surface 56, is configured as a curved surface in a cross section taken along the axis of drive shaft 52, with the outer diameter being greatest at the center in the axial direction of drive shaft 52 and gradually decreasing toward both ends, and has a shape that makes line contact with film material 11 along the film material conveyance direction. This reduces the dynamic frictional resistance of roller body 53 against pouch portion 12, and enables roller body 53 to roll without sliding against pouch portion 12 in the nip portion.

[0023] The elastic layer 55 is made of a thermoplastic elastomer having a Shore A hardness of, for example, 80 or more, which further reduces the dynamic friction resistance of the roller body 53 against the pouch portion 12. If the Shore A hardness is less than 80°, the dynamic friction resistance of the roller body 53 against the pouch portion 12 increases, making it easier for the branch portions 17 of the unnecessary portion 15 to be cut when the pouch portion 12 is separated. The elastic layer 55 in this embodiment is made of urethane rubber with a Shore A hardness of 90°, but the material is not limited to urethane rubber.

[0024] The operation of the bag making machine 10 of the above embodiment will be described below. The film material 11 is intermittently fed to the punching device 30 by the intermittent feed mechanism 20 while alternately repeating feeding and stopping, and when the intermittent feed stops, the Thomson blade 31 is pressed against the film material 11, thereby punching out the pouch portion 12 of the film material 11. At this time, the pouch portion 12 is not completely punched out, and a minute connecting portion 13 that connects to the unnecessary portion 15 remains on a part of the periphery of the pouch portion 12, and the unnecessary portion 15 is maintained in a continuous state as it is fed. At the separation position S, the unnecessary portion 15 of the film material 11 is conveyed by being pulled diagonally downward by the winding mechanism 40, while the end of the pouch portion 12 on the downstream side in the film material conveyance direction is pinched between one roller 51 and the other roller 58 and pulled in the film material conveyance direction, so that the minute connection portion 13 As if torn apart As a result, the pouch portion 12 is separated from the unnecessary portion 15 to obtain a pouch container P, and the unnecessary portion 15 is wound up and collected by the winding mechanism 40. The pouch container P is transported by the pouch container transport mechanism 60.

[0025] In the bag making machine 10, one roller 51 constituting the separation mechanism 50 is configured to make line contact with the pouch portion 12 in the film material conveyance direction, and the roller body 53 of one roller 51 constituting the nip portion has a high Shore hardness of 80° or more, thereby reducing the dynamic frictional resistance of the roller body 53 against the pouch portion 12. This allows the roller body 53 to roll without sliding against the pouch portion 12 in the nip portion, preventing the branch portion 17 from being severed by a shear force resulting from the difference in tensile force acting between one end portion of the branch portion 17 of the unnecessary portion 15 that connects to the base portion 16, which is continuous with the film material conveyance direction, and the other end portion that is discontinuous with the other unnecessary portion. This allows the pouch portion 12 to be reliably separated from the unnecessary portion 15 by cutting the minute connecting portion 13. Furthermore, even when the branch portion 17 is sandwiched between a pair of rollers, the nip portion is in a frictional state in which the branch portion 17 is returned to the base portion 16 where it is wound by the winding mechanism 40, so the branch portion 17 is not torn off and the unnecessary portion 17 can be prevented from being transported together with the pouch container P.

[0026] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, one roller 51 that contacts one side of the film material 11 is configured to make line contact with the film material 11 along the film material transport direction, but the other roller that contacts the other side of the film material 11 may be configured to make line contact with the film material 11 along the film material transport direction. Also, it is sufficient that the outer circumferential surface of the roller body 53 of one roller 51 is configured to make line contact with the film material 11 in the film material transport direction. Furthermore, in the above embodiment, the winding mechanism 40 is configured to be arranged below the film material transport path so that the unnecessary portion 15 of the film material 11 is pulled diagonally downward at the separation position S, but the winding mechanism 40 may also be configured to be arranged above the film material transport path so that the unnecessary portion 15 of the film material 11 is pulled diagonally upward at the separation position S. Furthermore, in the above embodiment, the pouch portion 12 is of a standing type, but the form of the pouch portion is not limited to a standing type, and may be of various forms such as a pouch container sealed on all four sides (flat pouch), a pouch container with a gusset, and a pouch container in which three sides of a folded film are sealed, etc. Furthermore, in the above embodiment, two pouch containers P are cut from the film material 11, but the number of pouch portions 12 (number of pieces) lined up in the width direction of the film material is not particularly limited. [Explanation of symbols]

[0027] 10... Bag making machine 11 Film material 12 Pouch part 13...Minute connection part 15... Unnecessary part 16 Base 17...branch part 20 Intermittent feed mechanism 30 ··· Punching device 31 Thomson blade 40... Winding mechanism 50... Separation mechanism 51 One of the rollers 52 Drive shaft 53 Roller body 54 Cylindrical core material 55 Elastic layer 56 Roller surface 58 Other roller 60 Pouch container conveying mechanism L punched wire P··· Pouch container S... Separation position

Claims

1. an intermittent feeding mechanism that intermittently feeds a resin film material formed so that bag-shaped pouch portions are continuous at predetermined intervals in a horizontal direction; a punching device that punches three sides of the periphery of the pouch portion with a Thomson blade so that an unnecessary portion remains and a minute connecting portion connected to the unnecessary portion is formed, each time the film material is intermittently fed, so that a continuous state in the film material conveyance direction is maintained; a winding mechanism that winds up an unnecessary portion of the film material so that the unnecessary portion is pulled in a direction intersecting a film material conveyance direction at a separation position where the pouch portion is separated from the film material; a separation mechanism that is disposed downstream of the separation position in a film material conveyance direction and pulls the pouch portion in the film material conveyance direction to cut the minute connected portion and separate it from the unnecessary portion; A bag making machine comprising: the separation mechanism includes a pair of rollers that sandwich the film material from one side and the other side, One of the pair of rollers is configured to be rotationally driven, and the one roller includes a drive shaft extending in a direction perpendicular to the film material conveying direction in a horizontal plane, and a plurality of roller bodies provided at predetermined intervals in the axial direction of the drive shaft, the outer peripheral surface of the roller body has a shape that makes line contact with the film material along the film material conveyance direction, a bag-making machine characterized in that the outer peripheral surface of the roller body, in a cross section taken along the axis of the drive shaft, is formed as a curved surface whose outer diameter is greatest at the center in the axial direction of the drive shaft and gradually decreases toward both ends.

2. A bag making machine as described in Claim 1, characterized in that the roller body has an elastic layer that forms a roller surface that contacts the pouch portion, and the Shore A hardness of the elastic layer is 80 or more.

3. The pouch portion is a standing type having a bottom seal portion that can stand up, 3. The bag making machine according to claim 1, wherein the punching device is configured to punch three sides of the periphery of the pouch portion excluding the bottom edge.

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