Web forming device and forming method, and double bag making machine

Abstract

This web forming device forms a double-folded double web comprising a first web and a second web. The web forming device comprises: a first tension adjustment mechanism that controls the tension of the first web being fed in the longitudinal direction; and a second tension adjustment mechanism that controls the tension of the second web being fed in the longitudinal direction independently of the first tension adjustment mechanism. The web forming device further comprises: a guide member located downstream of the first and second tension adjustment mechanisms and disposed to guide the first web and the second web downstream while overlapping the webs on each other; and a triangular plate located downstream of the guide member and disposed so as to fold in half the first web and the second web overlapped on each other.

Description

Technical Field

[0001] The present application relates to a web forming apparatus and a web forming method for forming a double-folded double web used for bag making of a double bag such as a double gusset web. The present application also relates to a bag making machine for sequentially manufacturing double bags.

Background Art

[0002] Double bags are widely known as disclosed in Patent Documents 1 and 2, for example. A double bag includes at least two double barrels facing each other. An accommodation space is formed between these two double barrels. Each double barrel consists of an inner barrel portion and an outer barrel portion that are overlapped with each other.

[0003] Furthermore, the double bags disclosed in Patent Documents 1 and 2 include a pair of double gussets. The double gusset also has a double structure and consists of an outer gusset portion and an inner gusset portion that are double-folded in an overlapped state with each other.

[0004] Patent Document 1 discloses a bag making machine for sequentially manufacturing such double bags. This bag making machine includes a gusset forming device for forming a double gusset web that becomes a double gusset. The gusset forming device unwinds an outer gusset web (for the outer gusset portion) and an inner gusset web (for the inner gusset portion) from their respective original rolls and overlaps them with each other. Then, the gusset forming device forms a double gusset web by double-folding the overlapped outer gusset web and inner gusset web along a folding line extending in their longitudinal directions.

[0005] Patent Document 1 double-folds an outer gusset web and an inner gusset web that are overlapped with each other using only one triangular plate. In a configuration where two webs are folded with one triangular plate in this way, usually, either one of the two webs may become slack or meandering. Therefore, it is difficult to neatly align and fold the outer gusset web and the inner gusset web. Naturally, if the finish of the double gusset web is poor, the quality of the completed bag will deteriorate.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

[0007] The present application provides a web forming apparatus and a web forming method for forming a neatly folded double web, and a bag making machine including the web forming apparatus.

[0008] The present application provides a web forming apparatus for manufacturing a double bag for forming a double web folded in two and including a first web and a second web. The web forming apparatus includes: a first tension adjusting mechanism for controlling the tension of the first web being fed in the longitudinal direction; a second tension adjusting mechanism for independently controlling the tension of the second web being fed in the longitudinal direction from the first tension adjusting mechanism; a guide member located downstream of the first and second tension adjusting mechanisms and arranged to guide the first web and the second web downstream while overlapping each other; and one triangular plate located downstream of the guide member and arranged to fold the first web and the second web overlapped with each other by the guide member in two along a bending line extending in the longitudinal direction thereof.

[0009] The web forming apparatus may be, for example, a gusset forming apparatus for forming a double gusset web including an outer gusset web as the first web and an inner gusset web as the second web as the double web.

[0010] The first tension adjusting mechanism may further convert the feeding of the first web from continuous feeding to intermittent feeding. The second tension adjusting mechanism may further convert the feeding of the second web from continuous feeding to intermittent feeding.

[0011] The first tension adjusting mechanism may be a first dancer mechanism. The second tension adjusting mechanism may be a second dancer mechanism. The first dancer mechanism may include a first dancer roller that engages with the first web to apply tension to the first web. The second dancer mechanism may include a second dancer roller that engages with the second web to apply tension to the second web.

[0012] The guide member may be, for example, a guide roller.

[0013] The web forming device may be provided downstream of the triangular plate and may further include a temporary fixing device that temporarily fixes the first web and the second web to each other.

[0014] In addition, in the present application, a bag making machine for sequentially manufacturing a double bag including a first double cylinder, a second double cylinder, and a double gusset is provided. The bag making machine an intermittent feeding device that intermittently feeds a first outer cylinder web, a first inner cylinder web, a second outer cylinder web, and a second inner cylinder web in their longitudinal directions; a pair of stacking rollers for stacking the first outer cylinder web, the first inner cylinder web, the second inner cylinder web, and the second outer cylinder web on top of each other in this order; a web forming device as the above-described gusset web forming device, which supplies the double gusset web so that when the first outer cylinder web, the first inner cylinder web, the second inner cylinder web, and the second outer cylinder web are stacked on top of each other at the position of the pair of stacking rollers, the double gusset web is interposed between the first inner cylinder web and the second inner cylinder web and is arranged in the longitudinal direction; Provided downstream of the pair of overlapping rollers, and at each intermittent feed, at least one heat-sealing device for heat-sealing the first and second outer barrel webs, the first and second inner barrel webs, and the double gusset web. Provided downstream of the heat-sealing device, and at each intermittent feed, a cross-cutting device for cross-cutting the first and second outer barrel webs, the first and second inner barrel webs, and the double gusset web in the width direction to form the double bag. The first double barrel is formed from the first outer barrel web and the first inner barrel web, the second double barrel is formed from the second outer barrel web and the second inner barrel web, and the double gusset is formed from the double gusset web.

[0015] The bag-making machine may further include a spout mounting device provided downstream of the pair of overlapping rollers and upstream of the heat-sealing device, and at each intermittent feed, mounting a spout on the first outer barrel web and the first inner barrel web that are overlapped with each other. The spout mounting device A plurality of guide rollers for temporarily separating the second outer barrel web, the second inner barrel web, and the double gusset web from the first outer barrel web and the first inner barrel web to provide a temporary separation section. A temporary fixing unit provided in the temporary separation section for temporarily fixing the first outer barrel web and the first inner barrel web to each other. A punching unit provided downstream of the temporary fixing unit in the temporary separation section for forming holes for the spout in the first outer barrel web and the first inner barrel web. A mounting unit provided downstream of the punching unit in the temporary separation section for inserting the spout into the hole and mounting the inserted spout on the first outer barrel web and the first inner barrel web by heat-sealing.

[0016] The web forming device may further include a punching device that forms holes for heat sealing in the double gusset web so that the first and second inner cylinder webs are welded to each other through the holes by the heat sealing device.

[0017] Furthermore, the present application provides a web forming method for forming a two-folded double web including a first web and a second web for manufacturing a double bag. The web forming method includes: feeding the first web in its longitudinal direction; feeding the second web in its longitudinal direction; controlling the tension of the first web by a first tension adjusting mechanism; controlling the tension of the second web independently of the tension control of the first web by the first tension adjusting mechanism by a second tension adjusting mechanism; guiding the first web and the second web downstream while overlapping them with each other by a guide member located downstream of the first and second tension adjusting mechanisms; by a single triangular plate located downstream of the guide member, folding the first web and the second web in half along a folding line extending in the longitudinal direction in a state where they overlap each other, and interposing the folded first web between the folded second webs.

[0018] The first web may include a first surface layer and a second surface layer having a lower melting point than the first surface layer, and the second web may have a lower melting point than the first surface layer. The first web and the second web may be folded in half along the folding line by the triangular plate such that the second surface layer contacts the second web.

[0019] The first web may be unwound from the first original fabric and continuously fed in its longitudinal direction. The second web may be unwound from the second original fabric and continuously fed in its longitudinal direction. The feeding of the first web may be converted from continuous feeding to intermittent feeding by the first tension adjusting mechanism. The feeding of the second web may be converted from continuous feeding to intermittent feeding by the second tension adjusting mechanism.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present application will be described with reference to the drawings. The following is merely an example of the present application.

[0022] FIG. 1A shows an exemplary double bag 1. The double bag 1 includes two double barrels 10 facing each other. As shown in the partial cross-sectional view of FIG. 1B, each double barrel 10 is composed of an outer barrel portion 100 and an inner barrel portion 101 that are overlapped with each other. An accommodation space is formed between these two double barrels 10. The two inner barrel portions 101 face each other and are interposed between the two outer barrel portions 100.

[0023] The double bag 1 further includes two double gussets 11. The two double gussets 11 are paired and are folded between the two double barrels 10 and extend along both side edges of the double barrels 10. That is, the exemplary double gusset 11 functions as a side gusset and expands the accommodation space of the bag 1.

[0024] As shown in FIG. 1B, the double gusset 11 is composed of an outer gusset portion 110 and an inner gusset portion 111 that are overlapped with each other. The outer gusset portion 110 is located outside the bag 1, and the inner gusset portion 111 is located inside the bag 1. When the double gusset 11 is folded as shown in FIG. 1B, the double-folded outer gusset portion 110 is interposed between the double-folded inner gusset portion 111.

[0025] The double bag 1 further includes a spout 12. The spout 12 is attached to one of the double barrels 10. Contents can be filled into or taken out from the accommodation space through the spout 12.

[0026] In order to ensure airtightness, the double bag 1 is provided with a first seal portion 13 formed along both side edges of the bag 1 and a second seal portion 14 formed along the upper and lower edges of the bag 1. In the first seal portion 13 and the second seal portion 14, each inner barrel portion 101 is welded to the adjacent outer barrel portion 100 and inner gasket portion 111, and the outer gasket portion 110 and the inner gasket portion 111 are welded to each other. Further, in a region where there is no double gasket 11 in the second seal portion 14, the two inner barrel portions 101 are welded to each other.

[0027] Similar to Patent Document 2, the double bag 1 further includes a third seal portion 15 that extends obliquely with respect to both side edges and upper and lower edges of the bag 1. The third seal portion 15 extends obliquely from the end of the folded edge (inner edge) of the double gasket 11 to the first seal portion 13. Also in the third seal portion 15, each inner barrel portion 101 is welded to the adjacent outer barrel portion 100 and inner gasket portion 111, and the outer gasket portion 110 and the inner gasket portion 111 are welded to each other.

[0028] Note that the opposing surfaces of the double-folded outer gasket portion 110 are not welded to each other.

[0029] Hereinafter, an exemplary bag-making machine for sequentially manufacturing the above-described exemplary double bag 1 will be described.

[0030] FIG. 2A schematically shows an upstream portion of an exemplary bag-making machine. Four webs 20’, 21’, 30’, 31’ are installed. The web 20’ is wound with a first outer barrel web 20 that will constitute the outer barrel portion 100 of one double barrel 10 (the first double barrel) of the bag 1. The web 21’ is wound with a first inner barrel web 21 that will constitute the inner barrel portion 101 of the first double barrel 10. The web 30’ is wound with a second outer barrel web 30 that will constitute the outer barrel portion 100 of the other double barrel 10 (the second double barrel) of the bag 1. The web 31’ is wound with a second inner barrel web 31 that will constitute the inner barrel portion 101 of the second double barrel 10.

[0031] The outer barrel webs 20 and 30 have, for example, a laminate structure. The outer barrel webs 20 and 30 each include a first surface layer such as a base material layer, and a second surface layer having a lower melting point than the first surface layer, such as a sealant layer. The inner barrel webs 21 and 31 may be made of a material having a lower melting point than the base material layer (first surface layer) of the outer barrel webs 20 and 30. Other characteristics (e.g., thickness) of these webs 20 - 31 are determined according to the characteristics of the bag 1 to be manufactured (e.g., the strength of the bag, etc.). This is the same as in Patent Document 1.

[0032] The bag-making machine includes a pair of laminating rollers 50 for laminating the webs 20 - 31 on top of each other. The webs 20 - 31 are each continuously fed out at a constant speed in their longitudinal direction from their original webs 20' - 31', sent, and then guided to the pair of laminating rollers 50 through an accumulator and dancer rollers (not shown) known in the art. Here, the dancer rollers are provided for each of the webs 20 - 31, and appropriately convert the feeding of the webs 20 - 31 from continuous feeding to intermittent feeding. Therefore, the webs 20 - 31 are fed intermittently and pass through the pair of laminating rollers 50. For this purpose, the bag-making machine includes an intermittent feeding device 53 (see FIGS. 5A and 5B) for intermittently feeding the webs 20 - 31 in their longitudinal direction at its downstream portion. Therefore, the webs 20 - 31 repeat feeding and pausing.

[0033] As shown in FIG. 2A, the webs 20 - 31 are guided to the pair of laminating rollers 50 and laminated on top of each other at the position of the pair of laminating rollers 50. The lamination order is, from top to bottom, the outer barrel web 20, the inner barrel web 21, the inner barrel web 31, and the outer barrel web 30. Here, the high-melting-point first surface layer (base material layer) of the outer barrel web 20 faces upward in the Z1 direction, and the low-melting-point second surface layer (sealant layer) faces downward in the Z2 direction and contacts the inner barrel web 21. The high-melting-point first surface layer of the outer barrel web 30 faces downward in the Z2 direction, and the low-melting-point second surface layer faces upward in the Z1 direction and contacts the inner barrel web 31.

[0034] In order to superpose the webs 20-31 in the above-described order and orientation, it is appropriately selected whether the original webs 20', 30' are wound with the webs 20, 30 with their first surface layers facing inward or outward, and guide members such as inclined plates that involve conversion of the orientation of the webs 20, 30 are installed in appropriate numbers at appropriate positions.

[0035] Furthermore, the bag-making machine includes a web forming device 6 (FIG. 7A) which will be described in detail later. In this embodiment, the web forming device 6 is a gusset forming device, and at a position upstream of the pair of overlapping rollers 50, a double gusset web 4 (an example of a double web folded in two) (FIGS. 2A, 2B) is supplied between the two inner barrel webs 21, 31 so that when the webs 20-31 are superposed on each other at the position of the pair of overlapping rollers 50, it is interposed between the inner barrel webs 21, 31 and is arranged in the longitudinal direction of the webs 20-31. Hereinafter, in this embodiment, the web forming device 6 is referred to as a gusset forming device.

[0036] As shown by the two arrows R1, R2 in FIG. 2B, the two double gusset webs 4 are supplied from both sides in the width direction of the webs 20-31, redirected in the direction X1, and extend along both sides of the webs 20-31. Therefore, downstream of the pair of overlapping rollers 50, the double gusset web 4 is intermittently fed in the longitudinal direction thereof, and thus in the direction X1, together with the webs 20-31 by the intermittent feeding device 53.

[0037] This double gusset web 4 will form the double gusset 11 of the bag 1. As shown in FIG. 6B, the double gusset web 4 is composed of an outer gusset web 40 and an inner gusset web 41 that are folded in half in a state of being overlapped with each other. The outer gusset web 40 will form the outer gusset portion 111 of the double gusset 11. The outer gusset web 40 has, for example, a laminate structure like the outer barrel webs 20 and 30, and includes a first surface layer (base material layer) and a second surface layer (sealant layer) having a lower melting point than the first surface layer. The inner gusset web 41 will form the inner gusset portion of the double gusset 11. The inner gusset web 41 is made of a material having a lower melting point than the first surface layer (base material layer) of the outer barrel webs 20 and 30 and the outer gusset web 40. As shown in FIGS. 2B and 6B, the double gusset web 4 is supplied such that its open edge 44 is aligned with the side edge of the webs 20-31 and its folded edge 43 is located inside.

[0038] FIGS. 3A and 3B show the middle part of an exemplary bag-making machine. The webs 20 and 21 will form the first double barrel 10 of the bag 1. Therefore, hereinafter, the webs 20 and 21 overlapped with each other may be referred to as the (first) double barrel web 2. Similarly, since the webs 30 and 31 overlapped with each other will form the second double barrel 10 of the bag 1, the webs 30 and 31 overlapped with each other may be referred to as the (second) double barrel web 3.

[0039] The bag-making machine further includes a spout mounting device 51 that is arranged downstream of the pair of overlapping rollers 50 and mounts the spout 12 on the first double barrel web 2 each time there is an intermittent feed.

[0040] The spout mounting device 51 includes a plurality of guide rollers 510 for separating the second double barrel web 3 and the double gusset web 4 from the first double web 2 and providing a temporary separation section where the webs 2, 3, and 4 are temporarily separated. As shown in FIG. 3B, in this example, the web 2 on which the spout 12 is mounted is fed horizontally as it is, and the webs 3 and 4 are temporarily separated downward in the Z2 direction. The temporary separation section prevents the webs 3 and 4 from getting in the way when the spout 12 is mounted on the web 2.

[0041] The spout mounting device 51 further includes a temporary fixing unit 511, a drilling unit 512, and a mounting unit 513 in this temporary separation section.

[0042] Figures 4A and 4B illustrate the region T of Figure 3A. The temporary fixing unit 511 temporarily fixes the webs 20, 21 to each other by heat-sealing them point by point each time the intermittent feed is temporarily stopped, thereby forming the point seal portion 16. This prevents the webs 20, 21 from shifting relative to each other until the spout 12 is mounted on the webs 20, 21 as shown in Figure 4C.

[0043] The point seal portion 16 is preferably located near the mounting position SA where the spout 12 is to be mounted. As shown in Figure 4A, for example, the point seal portion 16 is preferably included near this position SA and within the region CS where the later-described lateral seal is applied. Also, as shown in Figure 4B, an annular point seal portion 16 may be formed along the periphery of the position SA. The position of the point seal portion 16 in Figure 4B is the position that will be sealed by the later-described mounting unit 513.

[0044] In addition, as will be described later, the webs 2-4 are slit along their both side edges, and the scraps generated by the slits are removed. The point seal portion 16 may be formed in the portion removed as these scraps. Different from the examples in Figures 4A and 4B, two or more point seal portions may be provided for one position SA.

[0045] The drilling unit 512 is arranged at a position downstream from the temporary fixing unit 511 by a distance corresponding to one pitch of the intermittent feed. The drilling unit 512 forms a hole 17 (Figure 4C) for the spout 12 at the position SA of the web 2 (that is, the webs 20, 21 temporarily fixed by the point seal portion 16) each time the intermittent feed is stopped. The drilling unit 512 may form the hole 17 by punching the web 2 with a punch blade. The scraps generated by forming the hole 17 are sucked by a suction unit (not shown).

[0046] The mounting unit 513 is arranged at a position downstream by at least one pitch of the intermittent feed from the drilling unit 512, and mounts the spout 12 on the web 2 each time the intermittent feed stops. As shown in FIG. 4C, the spout 12 with the flange 120 is used. The mounting unit 513 has an annular heat-sealing block (not shown) corresponding to the shape of the flange 120. The mounting unit 513 inserts the spout 12 into the hole 17 from below, brings the heat-sealing block into contact with the web 20 from above, and heat-seals the flange 120 to the web 21. At this time, since the low-melting-point second surface layer of the web 20 is in contact with the web 21, the webs 20 and 21 are also heat-sealed to each other. Therefore, the spout 12, the web 20, and the web 21 are integrally welded.

[0047] The spout mounting device 51 further includes a spout detection unit 514 provided downstream of the mounting unit 513 within the temporary separation section. The spout detection unit 514 determines whether the spout 12 is properly mounted on the web 2 using a sensor (for example, an optical sensor) not shown. The spout detection unit 514 outputs a warning when the spout 12 is not properly mounted.

[0048] Since these units 511-514 themselves are of known types, detailed descriptions thereof are omitted here.

[0049] Thereafter, the webs 2-4 are overlapped with each other again by the downstream guide roller 510. The bag-making machine includes a temporary fixing device 52 provided downstream of the spout mounting device 51. The temporary fixing device 52 temporarily fixes these webs 2-4 to each other by heat-sealing and prevents these webs 2-4 from being displaced downstream. The temporary fixing position may be within the region (for example, the region CS in FIG. 4A) where heat-sealing is applied thereafter.

[0050] Figures 5A and 5B schematically show the downstream part of an exemplary bag-making machine. The bag-making machine includes an intermittent feeding device 53 that intermittently feeds the web 2-4 in its longitudinal direction. The intermittent feeding device 53 includes at least one pair of driving rollers 530. The pair of driving rollers 530 intermittently rotates by a servo motor while nipping the web 2-4, thereby intermittently feeding the web 2-4 in its longitudinal direction (direction X1). For example, a plurality of pairs of driving rollers 530 are appropriately arranged.

[0051] The bag-making machine further includes at least one heat-sealing device 54, 56 that is provided downstream of the temporary fixing device 52 and heat-seals the web 2-4 each time of intermittent feeding. In this example, a longitudinal sealing device 54 and a transverse sealing device 56 are provided.

[0052] Each time the intermittent feeding stops, the longitudinal sealing device 54 heat-seals the web 2-4 in its longitudinal direction to form a first seal portion 13 (see FIGS. 1A and 6A) along both side edges of the web 2-4. As described above, the webs 21, 31, 41 are made of a low melting point material. Therefore, as is clear from the positional relationship of each web 2-4 in FIG. 6B, the four layers of the webs 20, 21, 40, 41 are integrally welded, and the four layers of the webs 30, 31, 40, 41 are integrally welded. On the other hand, since the two surfaces of the two-folded outer gusset web 40 facing each other are the first surface layers of a high melting point, they are not welded to each other. This is the same for the following transverse seal.

[0053] The longitudinal sealing device 54 may heat-seal the web 2-4 by sandwiching it with a heat-sealing bar. Here, it is preferable to use a heat-sealing bar that is longer than twice the longitudinal dimension H (see FIG. 6A) of the bag 1 (corresponding to the feed pitch of the intermittent feeding). Thereby, the longitudinal sealing device 54 can heat-seal the same location at least twice.

[0054] Each time the intermittent feeding stops, the transverse sealing device 56 heat-seals the web 2-4 in its width direction to form a second seal portion 14 (see FIGS. 1A and 6A) across the entire width of the web 2-4. At this time, in the region where the web 4 does not exist, the inner barrel webs 21, 31 are welded to each other.

[0055] This exemplary horizontal sealing device 56 also forms the third seal portion 15 (see FIGS. 1A and 6A) together. For this purpose, the horizontal sealing device 56 may use a substantially K-shaped heat seal bar 560 as shown in FIG. 6C. Alternatively, the horizontal sealing device 56 may use a linear heat seal bar 561 for forming the second seal portion 14 and a bifurcated heat seal bar 562 for forming the third seal portion 15 as shown in FIG. 6D.

[0056] The root portions of the branches of the heat seal bar 560 and the heat seal bar 562 heat seal the central portion of the webs 2 and 3, and thus the region where the web 4 does not exist. This region has fewer layers of the web than the surrounding regions, thereby causing a step. This step may result in sealing defects. Therefore, in order to prevent sealing defects, additional point seals may be applied to this region.

[0057] The bag-making machine further includes a longitudinal cooling device 55 provided downstream of the longitudinal sealing device 54 and a transverse cooling device 57 provided downstream of the transverse sealing device 56. Each time of the intermittent feeding, the longitudinal cooling device 55 cools the first seal portion 13, and the transverse cooling device 57 cools the second and third seal portions 14 and 15. By this cooling, the seal surface can be smoothed to provide a well-finished seal surface.

[0058] The bag-making machine further includes a slitting device 58 provided downstream of the heat sealing devices 54 and 56 and the cooling devices 55 and 57, for slitting the webs 2-4 along both side edges of the webs 2 and 3. The slitting device 58 includes slitters disposed on both sides of the webs 2 and 3. Therefore, as the webs 2-4 are fed, they are slit along both side edges of the webs 2 and 3 by the slitters. The scraps generated at this time are wound up and collected by known means. The new edges of the webs 2-4 formed by the slitting have high linearity. Therefore, both side edges (the edges of the first seal portion 13) of the manufactured bag 1 will have high linearity.

[0059] The bag-making machine further includes a cross-cutting device 59 provided downstream of the slitting device 58, which cross-cuts the web 2-4 in its width direction at each intermittent feed to form the double bag 1. Specifically, at each stop of the intermittent feed, the cross-cutting device 59 uses a cutter to cross-cut the web 2-4 in its width direction, thereby obtaining the portion cut out from the web 2-4 as the double bag 1 in FIGS. 1A and 6A. This cross-cutting position is within the second seal portion 14 on the web 2-4, and more specifically, as indicated by the reference numeral CR in FIGS. 4A and 4B, it is the center line of the horizontal seal region CS.

[0060] The bag 1 completed by cross-cutting is conveyed by a conveyor (not shown).

[0061] Hereinafter, with reference to FIGS. 7A-9E, the configuration of a gusset forming device 6 (an example of a web forming device) for forming and supplying a double gusset web 4 (an example of a double-folded double web) will be described. The exemplary bag-making machine includes two gusset forming devices 6. One gusset forming device 6 supplies the web 4 from one side of the webs 20-31 as indicated by the arrow R1 in FIG. 2B, and the other gusset forming device (not shown in the accompanying drawings) supplies the web 4 from the other side of the webs 20-31 as indicated by the arrow R2. The configurations of both gusset forming devices are symmetric with respect to the direction X1. Therefore, the former gusset forming device 6 will be described, and the description of the latter gusset forming device will be omitted.

[0062] In the exemplary gusset forming device 6 in FIGS. 7A and 7B, two reels 40', 41' are installed. The reel 40' is wound with an outer gusset web 40 (an example of a first web) that will constitute the outer gusset portion 110 of the double gusset 11 of the bag 1. The reel 41' is wound with an inner gusset web 41 (an example of a second web) that will constitute the inner gusset portion 111.

[0063] The materials and configurations of the outer gusset web 40 and the inner gusset web 41 are as described above. In this illustration, the original web 40' is a web 40 with a laminate structure wound with its high melting point first surface facing outward and its low melting point second surface facing inward.

[0064] The gusset forming device 6 includes inclined plates 60 and 61 provided for each of the webs 40 and 41. FIGS. 9A and 9B are views along the arrow of line S1 in FIG. 7A and the arrow of line S2 in FIG. 7A, respectively. The webs 40 and 41 are continuously unwound from the original webs 40' and 41' at a constant speed in their longitudinal directions, sent to the inclined plates 60 and 61, and redirected from the upward direction Z1 to the horizontal direction Y1 by the inclined plates 60 and 61. The horizontal direction Y1 is a horizontal direction perpendicular to the feeding direction X1 of the webs 20 - 31 for the double cylinder 10. For this purpose, the bag making machine (gusset forming device 6) includes first and second continuous feeding devices 690 and 691 (shown only in FIG. 8), and the first / second continuous feeding devices 690 / 691 are provided in a section downstream of the inclined plates 60 / 61 and upstream of the first / second fixed rollers 621 / 631 with respect to the webs 40 / 41, and continuously feed the webs 40 / 41 in their longitudinal directions. The first and second continuous feeding devices 690 and 691 each include, for example, a pair of drive rollers.

[0065] The gusset forming device 6 further includes a first tension adjusting mechanism 62 for the outer gusset web 40 provided downstream of the inclined plate 60 and a second tension adjusting mechanism 63 for the inner gusset web 41 provided downstream of the inclined plate 61. The webs 40 and 41 pass through the first and second tension adjusting mechanisms 62 and 63 respectively after being redirected to the horizontal direction Y1 by the inclined plates 60 and 61.

[0066] The first tension adjusting mechanism 62 converts the feeding of the web 40 from continuous feeding to intermittent feeding, and appropriately controls the tension of the web 40 so that the web 40 is intermittently fed without slackening and without meandering. The second tension adjusting mechanism 63 converts the feeding of the web 41 from continuous feeding to intermittent feeding, and appropriately controls the tension of the web 41 so that the web 41 is intermittently fed without slackening and without meandering. The tension control of the web 40 by the first tension adjusting mechanism 62 and the tension control of the web 41 by the second tension adjusting mechanism 63 are independent of each other.

[0067] The first tension adjusting mechanism 62 of the embodiment is a first dancer mechanism, and includes a first dancer roller 620 that engages with the web 40 to apply tension to the web 40, and two first fixed rollers 621 that are provided immovably upstream and downstream of the first dancer roller 620 to guide the web 40 to engage with the first dancer roller 620.

[0068] Furthermore, as shown only in FIG. 8 that shows the region Q of FIG. 7 in detail, the first tension adjusting mechanism 62 includes a first actuator 622 that supports the first dancer roller 620 to be linearly movable (left and right in FIG. 8) and biases the first dancer roller 620 against the web 40, a first sensor 623 that detects the position of the first dancer roller 620, and a first controller 624 (composed of one or more processors) that controls the first continuous feeding device 690.

[0069] The first dancer roller 620 moves left and right in FIG. 8 as the web 40 is intermittently fed by the intermittent feeding device 53. At this time, the first sensor 623 detects the position of the first dancer roller 620. Then, the first controller 624 changes the feeding speed of the web 40 (the rotational speed of its driving roller pair) by the first continuous feeding device 690 based on the detection value of the first sensor 623. Through this series of controls, the first controller 624 keeps the movement of the first dancer roller 620 within a predetermined range, appropriately converts the feeding of the web 40 from continuous feeding to intermittent feeding while adjusting the tension of the web 40.

[0070] The second tension adjusting mechanism 63 of the embodiment is a second dancer mechanism having the same configuration as the first dancer mechanism. As shown in FIG. 8, it includes a second dancer roller 630, a second fixed roller 631, a second actuator 632, a second sensor 633, and a second controller 634 (composed of one or more processors).

[0071] The second sensor 633 detects the position of the second dancer roller 630 that moves as the web 41 is intermittently fed by the intermittent feeding device 53. Then, the second controller 634 changes the feeding speed of the web 41 (for example, the rotational speed of the continuous feeding roller pair) by the second continuous feeding device 691 based on the detection value of the second sensor 633, appropriately converts the feeding of the web 41 from continuous feeding to intermittent feeding while adjusting the tension of the web 41.

[0072] As the first and second tension adjusting mechanisms 62 and 63, other configurations may be adopted, not limited to the dancer mechanism. Instead of the above, the first and second controllers 624 and 634 may be composed of one controller, and this one controller may independently control the tensions of the webs 40 and 41.

[0073] Note that the webs 40 and 41 are intermittently fed by the intermittent feeding device 53 as described above. In addition to this, the gusset forming device 6 may be provided with an intermittent feeding device (composed of an appropriate number of drive roller pairs and a servo motor having the same configuration as the intermittent feeding device 53 of the bag making machine) (not shown). The feeding pitch of the intermittent feeding is indicated by the symbol P in Fig. 7A, which is set to be equal to the pitch of the intermittent feeding of the webs 20 - 31, and thus corresponds to the vertical dimension H (Fig. 6A) of the bag 1. Also, the timing of the intermittent feeding of both is set to be equal to each other.

[0074] The gusset forming device 6 further includes a guide member 64 provided downstream of the tension adjusting mechanisms 62 and 63, a single triangular plate 65 provided immediately downstream of the guide member 64, a crease roller pair 66 disposed downstream of the triangular plate 65, a temporary fixing device 67 for the webs 40 and 41 provided downstream of the crease roller pair 66, and a punching device 68 provided downstream of the temporary fixing device 67. The guide member 64 of the embodiment is a guide roller. These components 64 - 68 are arranged in the space between the two inner cylinder webs 21 and 31 before lamination upstream of the lamination roller pair 50 (Fig. 2A, etc.).

[0075] The webs 40 and 41 are each sent in the order of the guide member 64 and the triangular plate 65 after passing through the tension adjusting mechanisms 62 and 63. First, by the guide member 64, the webs 40 and 41 are overlapped with each other at the position of the guide member 64 as they are fed, and are guided to the triangular plate 65 in that state. At this time, the low melting point second surface layer of the outer gusset web 40 contacts the inner gusset web 41.

[0076] FIG. 9C is a view taken along line F of FIG. 7A, and FIG. 9D is an enlarged view taken along line J of FIG. 9C. As shown in FIGS. 7A, 9C, and 9D, the webs 40 and 41 that are overlapped with each other by the guide member 64 are folded in half along the bending line 42 (FIG. 9C) extending in the longitudinal direction by the triangular plate 65 as they are fed, and as shown in FIG. 9D, the folded outer gusset web 40 is interposed between the folded inner gusset web 41. Then, the webs 40 and 41 pass through the crease roller pair 66, and at this time, the folding in half is completed by the crease roller pair 66, and the crease is emphasized. The webs 40 and 41 are redirected from the direction Y1 to the direction X1 by passing through the guide member 64 and the triangular plate 65.

[0077] In this way, the double gusset web 4 is formed. The bending line 42 coincides with the center line in the width direction of the webs 40 and 41. Note that the reference numeral 43 in FIGS. 7A and 9D indicates the bent edge 43 of the double gusset web 4, which is formed at the position of the bending line 42. The reference numeral 44 is the open edge of the double gusset web 4. The two surfaces of the folded web 40 facing each other become the first surface layer of high melting point.

[0078] The gusset temporary fixing device 67 temporarily fixes the webs 40 and 41 in the form of heat sealing or ultrasonic sealing each time there is an intermittent feed to form the point seal portion 18 (see FIG. 9E, which is an enlarged view of the region G in FIG. 7A). Thereby, displacement of the webs 40 and 41 is prevented. The position of the point seal portion 18 is, for example, within the above-described horizontal seal region CS.

[0079] The punching device 68 forms holes 19 for heat sealing (FIG. 9E) in the double gusset web 4 each time there is an intermittent feed. The position of the holes 19 is within the horizontal seal region CS. Also, the holes 19 are formed, for example, on both sides with respect to the above-described cross-cut position CR.

[0080] The punching device 68 may form the holes 19 by punching the web 4 with a punch blade, for example. Similar to known punching devices, the punching device 68 is provided with a suction unit (not shown) that sucks chips generated when forming the holes 19. Further, the punching device 68 is provided with a chip detection unit (not shown), which uses a sensor to detect whether chips are not sucked and adhere to the web 4, and outputs a warning when chips adhere to the web 4.

[0081] As described above, when the webs 20 - 31 for the double cylinder 10 are overlapped with each other at the position of the overlapping roller pair 50, the double gusset web 4 is interposed between the inner cylinder webs 21, 31. At this time, as shown in FIG. 2B, the open edge 44 is aligned with the side edge of the webs 20 - 31, and the bent edge 43 is located inside, as described above.

[0082] In this example, when the horizontal sealing device 56 heat - seals the webs 2 - 4 in their width direction, the point seal portion 18 is completely included in the second seal portion 14 and integrated and disappears, and the inner cylinder webs 21, 31 are welded to each other through the holes 19.

[0083] When the inner gusset web and the outer gusset web are folded in half with one triangular plate as in Patent Document 1, usually, either one becomes slack or meanders, and as a result, the finish of the double gusset web may deteriorate.

[0084] To address this problem, the gusset forming device 7 according to the related art in FIG. 10A includes triangular plates 70, 71 provided for each of the webs 40, 41, and a disk - shaped rotatable guide plate 72 provided downstream of the triangular plates 70, 71. Then, the gusset forming device 7 tries to fold the web 40 in half with the triangular plate 70 and the web 41 in half with the triangular plate 71, and then align the bent edges of both webs 40, 41 with the guide plate 72. However, in the combination of the two triangular plates 70, 71 and the disk - shaped guide plate 72, a gap 45 may occur between the web 40 and the web 41 as shown in FIG. 10B, and as a result, there may be a problem of adversely affecting the finish of the double bag 1.

[0085] As described above, the gusset forming device 6 of the present application bends the webs 40 and 41 overlapped with each other by one triangular plate 65. However, upstream thereof, the first and second tension adjusting mechanisms 62 and 63 respectively perform tension control on the webs 40 and 41 independently of each other. Therefore, the problems of the prior art in which the webs 40 and 41 are slack or meander when forming the double gusset web 4 do not occur. Further, since the webs 40 and 41 overlapped with each other are folded in half together, the gap 45 of the related art described above does not occur either.

[0086] Therefore, the gusset forming device 6 of the present application can form a double gusset web 4 with a better finish than the prior art and the related art. Therefore, the bag making machine of the present application provided with this gusset forming device 6 can provide a high-quality double bag 1.

[0087] The double bag 1 described above may be used, for example, as an inner bag of a bag-in-box in the same manner as in Patent Document 2.

[0088] Instead of the laminate structure, the webs 20, 30, and 40 may be composed of a single-material film and a medium ink that inhibits heat sealing partially or entirely applied to the film. The webs 20-41 may be composed of paper as a base material and a resin partially or entirely coated on the paper. As long as the double bag 1 can be formed, it is obvious to those skilled in the art that the webs 20-41 are not limited to the configurations and materials exemplified above.

[0089] Alternatively, the webs 20 and 30 may be formed by slitting a wide web fed from one roll. The webs 21 and 31 may also be formed by slitting a wide web fed from one roll.

[0090] The main role of the stacking roller pair 50 is to gather the conveyance lines of the webs 2, 3, and 4, rather than to convey the webs 2, 3, and 4. Therefore, the stacking roller pair 50 does not necessarily nip the webs 2, 3, and 4, and its nip force can be very weak or even zero. Conversely, if the nip force is too strong, there is a possibility of layer displacement between the layers in the laminate of the webs 2, 3, and 4, so this must be noted.

[0091] In the above embodiment, the double web formed by the web forming device 6 is used as a double gusset web. In another embodiment, the double web formed by the web forming device 6 having the same configuration as above is used as a double-folded double-barrel web.

[0092] In this another embodiment, after the double-folded double-barrel web is formed by the web forming device 6, it undergoes at least a heat-sealing process and a cross-cutting process by a bag-making machine to manufacture a double bag without gussets. This double bag includes a double-folded outer barrel and a double-folded inner barrel interposed between the outer barrels. The outer barrel is formed from the second web 41 of the double-barrel web, and the inner barrel is formed from the first web 40 of the double-barrel web. In this another embodiment, in order to realize the heat-sealing process, a material with a high melting point is used for the outer layer of the second web 41, a material with a low melting point is used for the inner layer, and a material with a low melting point is used for the first web 40.

[0093] The bag-making machine of the present application may manufacture a double bag having a chuck instead of or in addition to the spout 12. The bag-making machine of the present application may manufacture a double bag with a double gusset that functions as a top gusset or a bottom gusset instead of the double gusset 11 that functions as a side gusset as exemplified above. That is, bag-making may be carried out using the double gusset web 4 as a top gusset and / or a bottom gusset.

Explanation of Reference Numerals

[0094] 1 Double bag 10 Double barrel 11 Double gusset 12 Spout 17 Hole for spout 19 Hole for heat seal 2 First double-barrel web 20 First outer barrel web 21 First inner barrel web 3 Second double-barrel web 30 Second outer barrel web 31 Second inner barrel web 4 Double gusset web (an example of a double web folded in two) 40 Outer gusset web (an example of the first web) 41 Inner gusset web (an example of the second web) 42 Fold line 50 Stacking roller pair 51 Spout mounting device 510 Guide roller 511 Temporary fixing unit 512 Drilling unit 513 Mounting unit 53 Intermittent feeding device 54 Longitudinal sealing device (an example of a heat sealing device) 56 Transverse sealing device (an example of a heat sealing device) 59 Cross-cutting device 6 Web forming device (gusset forming device) 62 First tension adjusting mechanism (first dancer mechanism) 620 First dancer roller 63 Second tension adjusting mechanism (second dancer mechanism) 630 Second dancer roller 64 Guide member (guide roller) 65 Triangular plate 67 Temporary fixing device

Claims

1. A bag making machine for sequentially manufacturing double-layered bags having a first double-layered body, a second double-layered body, and a double-layered gusset, comprising: an intermittent feeding device that intermittently feeds the first outer body web, the first inner body web, the second outer body web, and the second inner body web in a longitudinal direction of the first outer body web, the first inner body web, the second outer body web, and the second inner body web; a pair of overlapping rollers for overlapping the first outer body web, the first inner body web, the second inner body web, and the second outer body web on one another in this order; a gusset forming device that forms a double gusset web having an outer gusset web and an inner gusset web, and supplies the double gusset web so that when the first outer body web, the first inner body web, the second inner body web and the second outer body web are overlapped with each other at the position of the overlapping roller pair, the double gusset web is interposed between the first inner body web and the second inner body web and arranged in the longitudinal direction; at least one heat sealing device provided downstream of the overlapping roller pair and heat-sealing the first and second outer body webs, the first and second inner body webs, and the double gusset web at each intermittent feed; a cross-cutting device that is provided downstream of the heat-sealing device and that cross-cuts the first and second outer body webs, the first and second inner body webs, and the double gusset web in the width direction of the first and second outer body webs, the first and second inner body webs, and the double gusset web at each intermittent feed to form the double bag, The first double barrel is formed from the first outer barrel web and the first inner barrel web, the second double barrel is formed from the second outer barrel web and the second inner barrel web, and the double gusset is formed from the double gusset web, The gusset forming device includes: a first tension adjustment mechanism for controlling the tension of the outer gusset web being fed in the longitudinal direction of the outer gusset web; a second tension adjustment mechanism that controls the tension of the inner gusset web being fed in the longitudinal direction of the inner gusset web independently of the first tension adjustment mechanism; a guide member located downstream of the first and second tension adjustment mechanisms and arranged to guide the outer gusset web and the inner gusset web downstream while overlapping each other; a triangular plate located downstream of the guide member and arranged to fold the outer gusset web and the inner gusset web overlapped with each other by the guide member in half along a fold line extending in the longitudinal direction of the outer gusset web and the inner gusset web, Bag making machine.

2. The first tension adjustment mechanism further converts the feeding of the outer gusset web from continuous feeding to intermittent feeding, The second tension adjustment mechanism further converts the feeding of the inner gusset web from continuous feeding to intermittent feeding.

2. The bag making machine according to claim 1.

3. the first tension adjustment mechanism is a first dancer mechanism, the second tension adjustment mechanism is a second dancer mechanism, The first dancer mechanism includes a first dancer roller that engages the outer gusset web to apply tension to the outer gusset web, The second dancer mechanism includes a second dancer roller that engages the inner gusset web to apply tension to the inner gusset web.

2. The bag making machine according to claim 1.

4. The gusset forming device includes: Further, a temporary fastening device is provided downstream of the triangular plate and temporarily fastens the outer gusset web and the inner gusset web to each other.

2. The bag making machine according to claim 1.

5. The guide member is a guide roller.

2. The bag making machine according to claim 1.

6. A spout attachment device is provided downstream of the overlapping roller pair and upstream of the heat sealing device, and attaches a spout to the overlapping first outer body web and the overlapping first inner body web at each intermittent feed, The spout mounting device is a plurality of guide rollers for temporarily separating the second outer body web, the second inner body web, and the double gusset web from the first outer body web and the first inner body web to provide a temporary separation section; a temporary fastening unit provided in the temporary separation section and configured to temporarily fasten the first outer body web and the first inner body web to each other; a hole making unit provided downstream of the temporary fastening unit in the temporary separation section, the hole making unit forming holes for the spouts in the first outer body web and the first inner body web; and an attachment unit provided downstream of the hole punching unit in the temporary separation section, which inserts the spout into the hole and attaches the inserted spout to the first outer body web and the first inner body web by heat sealing.

2. The bag making machine according to claim 1.

7. The gusset forming device further includes a hole punching device that forms holes for heat sealing in the double gusset web so that the first and second inner body webs are welded to each other through the holes by the heat sealing device.

2. The bag making machine according to claim 1.

8. A bag making method for sequentially manufacturing a double-layered bag having a first double-layered body, a second double-layered body, and a double-layered gusset, comprising the steps of: intermittently feeding the first outer body web, the first inner body web, the second outer body web, and the second inner body web in a longitudinal direction of the first outer body web, the first inner body web, the second outer body web, and the second inner body web by an intermittent feeding device; using a pair of overlapping rollers to overlap the first outer body web, the first inner body web, the second inner body web, and the second outer body web in this order; forming a dual gusset web comprising an outer gusset web and an inner gusset web with a gusset forming device; supplying the double gusset web by the gusset forming device so that when the first outer body web, the first inner body web, the second inner body web and the second outer body web are overlapped with each other at the position of the overlapping roller pair, the double gusset web is interposed between the first inner body web and the second inner body web and positioned in the longitudinal direction; a heat sealing device heat-sealing the first and second outer body webs, the first and second inner body webs, and the double gusset web at each intermittent feed downstream of the overlapping roller pair; and a cross-cutting device that cross-cuts the first and second outer body webs, the first and second inner body webs, and the double gusset web in a width direction of the first and second outer body webs, the first and second inner body webs, and the double gusset web at each intermittent feed downstream of the heat sealing device to form the double bag; The first double barrel is formed from the first outer barrel web and the first inner barrel web, the second double barrel is formed from the second outer barrel web and the second inner barrel web, and the double gusset is formed from the double gusset web, forming the dual gusset web comprises: feeding the outer gusset web in a longitudinal direction of the outer gusset web; Feeding the inner gusset web in a longitudinal direction of the inner gusset web; Controlling the tension of the outer gusset web with a first tension adjustment mechanism; A second tension adjustment mechanism controls the tension of the inner gusset web independently of the tension control of the outer gusset web by the first tension adjustment mechanism; a guide member located downstream of the first and second tension adjustment mechanisms guides the outer gusset web and the inner gusset web downstream while overlapping each other; and a triangular plate located downstream of the guide member folds the outer gusset web and the inner gusset web in half along a fold line extending in the longitudinal direction of the outer gusset web and the inner gusset web while the outer gusset web and the inner gusset web are overlapped with each other, and the folded outer gusset web is interposed between the folded inner gusset web. Bag making method.

9. The outer gusset web has a first surface layer and a second surface layer having a melting point lower than that of the first surface layer, and the inner gusset web has a melting point lower than that of the first surface layer; The outer gusset web and the inner gusset web are folded in half along the fold line by the triangular plate so that the second surface layer contacts the inner gusset web. The bag making method according to claim 8.

10. The outer gusset web is unwound from a first roll and continuously fed in a longitudinal direction of the outer gusset web, The inner gusset web is unwound from a second roll and continuously fed in a longitudinal direction of the inner gusset web, The feeding of the outer gusset web is converted from continuous feeding to intermittent feeding by the first tension adjustment mechanism, The feeding of the inner gusset web is converted from continuous feeding to intermittent feeding by the second tension adjustment mechanism. The bag making method according to claim 8.

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