Bag making machine

Abstract

The web overlapping device slits the first main web with a first slitter to form a first outer body web and a second outer body web. The overlapping device slits the second main web with a second slitter to form a first inner body web and a second inner body web. The overlapping device guides the first and second outer body webs to the overlapping roller pair. The overlapping device separates the first and second outer body webs from each other until the first and second outer body webs reach the overlapping roller pair to provide a space between the first and second outer body webs. The overlapping device guides the first and second inner body webs through the space to the overlapping roller pair so that the four webs are overlapped on each other at the overlapping roller pair.

Description

[Technical field]

[0001] The present application relates to a web overlapping device for a bag making machine for successively producing double-ply bags.The present application also relates to a bag making machine for successively producing double-ply bags. [Background technology]

[0002] Double-ply bags are widely known, as disclosed in, for example, Patent Documents 1 and 2. The double-ply bag includes at least two composite sheets facing each other. A storage space is formed between the two composite sheets. Each composite sheet is composed of an inner body portion and an outer body portion that are overlapped with each other. Thus, the double-ply bag is composed of two inner body portions and two outer body portions, i.e., at least four sheets.

[0003] Patent Document 1 also discloses a bag making machine that sequentially produces double-ply bags. This bag making machine pays out webs from four original rolls installed at the most upstream of the bag making machine. Two original rolls are for the outer body portion, and the remaining two original rolls are for the inner body portion. The bag making machine is provided with a web overlapping device consisting of a guide roller, overlapping roller pairs, etc., which overlaps the four webs paid out from each original roll. The overlapped webs are sent to a processing device such as a heat sealing device and processed.

[0004] As in Patent Document 1, four rolls of raw material are required to manufacture a double-ply bag. Due to slight differences in the feed speed and winding amount of the four rolls of raw material, there may be a slight difference in the timing when the four rolls of raw material run out. If this occurs repeatedly, the timing for replacing the four rolls of raw material may be off, and as a result, the effort required for replacing the rolls may increase. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-141427 A [Patent Document 2] Patent Publication No. 2022-7011 Summary of the Invention

[0006] The present application provides a web overlapping device for a bag making machine configured to sequentially manufacture double-ply bags, the double-ply bags having a first outer body portion, a second outer body portion, a first inner body portion, and a second inner body portion, the first and second inner body portions facing each other and interposed between the first and second outer body portions.

[0007] The web overlapping device is a first slitter for slitting a first main web unwound from a first roll into a first outer body web for the first outer body portion and a second outer body web for the second outer body portion when the first main web is fed; a second slitter for slitting the second main web when the second main web is fed from the second roll into a first inner body web for the first inner body portion and a second inner body web for the second inner body portion; A pair of stacking rollers; a first guide mechanism that guides the first main web through the first slitter and guides the first and second outer body webs to the pair of overlapping rollers, the first guide mechanism separating the first and second outer body webs from each other until the first and second outer body webs reach the pair of overlapping rollers to form a space between the first outer body web and the second outer body web; and a second guide mechanism that guides the second main web through the second slitter and guides the first and second inner body webs from the space to the overlapping roller pair so that the first outer body web, the second outer body web, the first inner body web, and the second inner body web are overlapped with each other at the overlapping roller pair.

[0008] The overlapping roller pair may be spaced apart from the first and second webs in a forward horizontal direction.

[0009] The first guide mechanism includes: A first separation guide member for redirecting the first outer body web from a lateral direction perpendicular to the forward horizontal direction to an upward direction and the second outer body web from the lateral direction to a downward direction; A first downstream horizontal roller provided downstream of the first separation guide member for redirecting the first outer body web from an upward direction to the forward horizontal direction; It may also include a second downstream horizontal roller disposed downstream of the first separation guide member for redirecting the second outer body web from a downward direction to the forward horizontal direction.

[0010] The second guide mechanism includes: A second separation guide member for redirecting the first inner body web from the lateral direction to an upward direction and the second inner body web from the lateral direction to a downward direction; A third downstream horizontal roller provided downstream of the second separation guide member for redirecting the first inner body web from the upward direction to the forward horizontal direction; It may also include a fourth downstream horizontal roller provided downstream of the second separation guide member for changing the direction of the second inner body web from a downward direction to the forward horizontal direction.

[0011] The second slitter and the second separation guide member may be spaced apart in the forward horizontal direction from the first separation guide member and positioned below the first downstream horizontal roller and above the second downstream horizontal roller.

[0012] The third and fourth downstream horizontal rollers may be spaced apart in the forward horizontal direction from the first separation guide member and positioned below the first downstream horizontal roller and above the second downstream horizontal roller.

[0013] The second guide mechanism may further include a plurality of diverting rollers for diverting the second main web in the lateral direction away from the first slitter and the first separating guide member.

[0014] The first guide mechanism may further include a first downstream vertical roller for redirecting the first main web from the forward horizontal direction to the lateral direction and passing it through the first slitter. The first slitter may be positioned to slit the first main web being fed in the lateral direction through the first downstream vertical roller.

[0015] The second guide mechanism may further include a second downstream vertical roller for redirecting the second main web from the forward horizontal direction to the lateral direction and passing it through the second slitter. The second slitter may be positioned to slit the second main web being fed in the lateral direction through the second downstream vertical roller.

[0016] The first and second guide mechanisms may be configured to guide the first and second outer body webs and the first and second inner body webs so that when the first and second outer body webs and the first and second inner body webs are overlapped, edges created by the slits in the first and second outer body webs and the first and second inner body webs all face in the same direction.

[0017] The present application further provides a bag making machine for sequentially producing double-layered bags, the bag making machine including the web overlapping device described above.

[0018] The bag making machine comprises: a feed device provided downstream of the overlapping roller pair for intermittently feeding the first and second outer cylinder webs and the first and second inner cylinder webs; a first dancer roller for engaging with the first outer body web upstream of the overlapping roller pair to switch the first outer body web from continuous feeding to intermittent feeding; a second dancer roller for engaging with the second outer body web upstream of the overlapping roller pair to switch the second outer body web from continuous feeding to intermittent feeding; a first link mechanism for interlocking the first and second dancer rollers with each other; The machine may further include a first biasing member for biasing the first and second dancer rollers toward the first and second outer body webs, respectively, via the first link mechanism.

[0019] The bag making machine comprises: a third dancer roller for engaging with the first inner cylinder web upstream of the overlapping roller pair to switch the first inner cylinder web from continuous feeding to intermittent feeding; a fourth dancer roller for engaging with the second inner cylinder web upstream of the overlapping roller pair to switch the second inner cylinder web from continuous feeding to intermittent feeding; a second link mechanism for interlocking the third and fourth dancer rollers with each other; The apparatus may further include a second biasing member for biasing the third and fourth dancer rollers toward the first and second inner body webs, respectively, via the second link mechanism.

[0020] The bag making machine comprises: a feed device provided downstream of the overlapping roller pair for intermittently feeding the first and second outer cylinder webs and the first and second inner cylinder webs; a sealing device provided downstream of the pair of overlapping rollers and configured to heat-seal the first and second outer body webs and the first and second inner body webs; The machine may further include a cross-cutting device that is provided downstream of the sealing device and cross-cuts the first and second outer body webs and the first and second inner body webs in their width direction each time the machine is intermittently fed to form the double-layered bag. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1A shows an exemplary dual bladder, and FIG. 1B is a partial cross-sectional view of the bladder of FIG. 1A. [Diagram 2] FIG. 2A is a schematic plan view and FIG. 2B is a side view of the upstream portion of an exemplary bag making machine. [Diagram 3] FIG. 3 is a schematic side view of the downstream portion of the bag making machine of FIG. 2A. [Figure 4] 4A and 4B show an exemplary accumulator. [Diagram 5] FIG. 5 is a schematic side view of an exemplary stacking apparatus. [Figure 6] FIG. 6 shows views of arrows AA, BB, CC, and DD in FIG. [Figure 7] FIG. 7 is a plan view of FIG. [Figure 8] FIG. 8A illustrates a position adjustment configuration for the first main web, FIG. 8B is an enlarged view of area T of FIG. 8A, FIG. 8C illustrates an inclined plate, FIG. 8D shows an enlarged cross section SS of FIG. 8C, and FIG. 8E illustrates a position adjustment configuration for the second main web. [Figure 9] FIG. 9A illustrates another alignment configuration, and FIG. 9B is an enlarged view of region T of FIG. 9A. [Figure 10] FIG. 10 illustrates an example of a configuration for interlocking the dancer rollers. [Figure 11] FIG. 11 illustrates a configuration for reducing the swing amplitude of the arm of the link mechanism. [Figure 12] FIG. 12A is a schematic plan view of another exemplary stacking apparatus, and FIG. 12B is a side view thereof. [Figure 13] FIG. 13 shows views of arrows AA, BB, CC, and DD in FIG. 12B. [Figure 14] FIG. 14A is a schematic plan view of another exemplary stacking apparatus, and FIG. 14B is a side view thereof. [Figure 15] FIG. 15 shows views of arrows AA, BB, CC, and DD in FIG. 14B. [Figure 16] FIG. 16A is a schematic plan view of another exemplary stacking apparatus, and FIG. 16B is a side view thereof. [Figure 17] FIG. 17 shows views of arrows AA, BB, CC, and DD in FIG. 16B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, embodiments of the present application will be described with reference to the drawings, which are merely exemplary of the present application. The drawings are only schematic and may not be drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to represent the same or similar components.

[0023] FIG 1A shows an example bag 1. Bag 1 includes composite sheets 10 facing each other. As shown in the partial cross-sectional view of FIG 1B, each composite sheet 10 includes an outer body 11 and an inner body 12 overlapped with each other. Bag 1 includes a first sealed portion 13 formed along both side edges of bag 1, and a second sealed portion 14 formed along the top and bottom edges of bag 1. Bag 1 also includes a spout 15 attached to one of the composite sheets 10. Contents can be filled into or removed from the storage space between the two composite sheets 10 through spout 15.

[0024] 2A and 2B are schematic diagrams showing an upstream portion of an exemplary bag making machine for sequentially producing the bag 1 of FIG. 1. Two original rolls 2' and 3' are provided. One original roll 2' is wound with the first main web 2 for the outer body portion 11 described above. The other original roll 3' is wound with the second main web 3 for the inner body portion 12 described above. In this example, the original roll 2' is disposed on the lower side, and the original roll 3' is disposed on the upper side. The direction X1 is the horizontal forward direction of the web, and the direction X2 is the opposite direction to X1. The directions Y1 and Y2 are horizontal directions perpendicular to the direction X1, and are horizontal directions. Y1 is the first horizontal direction, and the direction Y2 is the second horizontal direction. Z1 is the upward direction, and Z2 is the downward direction.

[0025] The web 2 has, for example, a laminate structure. One surface layer (base layer) of the web 2 has a higher melting point than the other surface layer (sealant layer). The web 3 may be made of a material having a lower melting point than the base layer of the web 2. Other characteristics (e.g., thickness) of the webs 2 and 3 are determined according to the characteristics of the bag 1 to be manufactured (e.g., strength of the bag, etc.). This is similar to Patent Document 1.

[0026] The webs 2 and 3 are unwound from original rolls 2 ′ and 3 ′, respectively, and are continuously fed in their longitudinal direction at a predetermined speed to pass through an accumulator 80 .

[0027] The accumulator 80 has a function of temporarily storing the webs 2 and 3 for a certain length. In the accumulator 80 illustrated in FIG. 4A, a group of fixed rollers 801 and a group of movable rollers 802 are provided for each of the webs 2 and 3. The webs 2 and 3 are alternately engaged with the fixed rollers and the movable rollers, respectively. As shown in FIG. 4A and FIG. 4B, the accumulator 80 adjusts the amount of storage by moving the group of movable rollers 802 closer to and away from the group of fixed rollers 801 by an actuator (not shown). FIG. 4A shows a case where the amount of storage is large. FIG. 4B shows a case where the amount of storage is small.

[0028] When the amount of web wound on the web becomes small, the operator replaces the web with a new one. During the replacement with a new web, the web is not fed to the accumulator 80. During this time, the accumulator 80 feeds the stored web downstream. The operator completes the web replacement before the amount of web stored reaches zero. The accumulator 80 then increases the amount of web stored and increases the unwinding speed from the web. This allows the web to continue to be fed to each device located downstream even during the work of replacing the web, making it possible to continue the bag making process.

[0029] 2B, the bag making machine further includes a web overlapping device 4. The overlapping device 4 slits the first main web 2 (unwound from the first original roll 2') in its longitudinal direction to divide it into two outer body webs 20a, 20b, and slits the web 3 (unwound from the second original roll 3') in its longitudinal direction to divide it into two inner body webs 30a, 30b. This configuration will be described in detail later.

[0030] The bag making machine further includes dancer rollers 70a-71b provided for each of the four webs 20a-30b, and switches the feed of the webs 20a, 20b / 30a, 30b from continuous to intermittent by the dancer rollers 70a, 70b / 71a, 71b. Therefore, downstream of the dancer rollers 70a, 70b, 71a, 71b, the webs 20a-30b repeatedly feed and pause.

[0031] The overlapping device 4 is provided with a pair of overlapping rollers 40 at a position away from the original webs 2', 3' in the forward horizontal direction X1. The overlapping device 4 guides the four webs 20a-30b to the pair of overlapping rollers 40 after passing through the dancer rollers 70a-71b, and passes the pair of overlapping rollers 40. At this time, the overlapping device 4 overlaps the four webs 20a-30b with each other at the pair of overlapping rollers 40. The overlapping order is, from the top, the outer body web 20a, the inner body web 30a, the inner body web 30b, and the outer body web 20b. Here, the high melting point surface layer (base material layer) of the outer body web 20a faces the upward direction Z1, and the low melting point surface layer (sealant layer) faces the downward direction Z2 and contacts the inner body web 30a. The high melting point surface layer of the outer body web 20b faces the downward direction Z2, and the low melting point surface layer faces the upward direction Z1 and contacts the inner body web 30b. The configuration for this will also be described in detail later.

[0032] 3 shows a schematic diagram of a downstream portion of the bag making machine of FIGS. 2A and 2B. The bag making machine further includes at least one feed device 84 provided downstream of the overlapping roller pair 40. The feed device 84 includes, for example, a drive roller pair and a servo motor. When the drive roller pair is rotated intermittently by the servo motor, the web 20a-30b sandwiched between the drive roller pair is intermittently fed. The conveying direction is indicated by X1.

[0033] The bag making machine further includes a spout attachment device 81 provided downstream of the overlapping roller pair 40. The spout attachment device 81 includes a plurality of guide rollers 810, and temporarily separates the four overlapping webs 20a-30b into two webs 20a, 30a (which become one composite sheet 10) and two webs 20b, 30b (which become the other composite sheet 10). The spout attachment device 81 then attaches the spouts 15 to the webs 20a, 30a in this separation section at each intermittent feed. For this purpose, the spout attachment device 81 includes a hole punching unit that punches holes in the webs 20a, 30a, a sealing unit that inserts the spouts 15 into the holes and seals the webs 20a, 30a, and the like. Such hole punching units and sealing units may have the same configurations as those in Patent Document 1, for example.

[0034] The bag making machine further includes at least one heat sealing device 82, 83 provided downstream of the overlapping roller pair 40. The heat sealing devices 82, 83 use a heat seal bar to heat seal the webs 20a-30b at each intermittent feed. As described above, the low melting point surface layers of the webs 20a, 20b come into contact with the low melting point inner body webs 30a, 30b, respectively. Therefore, the inner body webs 30a, 30b are heat sealed to each other and also to the outer body webs 20a, 20b, respectively. In this way, the sealed portions 13, 14 of the bag 1 are formed.

[0035] The bag making machine further includes a cross-cutting device 85 disposed downstream of the heat-sealing devices 82, 83. The cross-cutting device 85 cross-cuts the four webs 20a-30b in their width direction using a cutter at each intermittent feed. A bag 1 is formed at each cross-cut. Two outer body sections 11 are formed from the portions cut out of the outer body webs 20a, 20b by the cross-cutting. Two inner body sections 12 are formed from the portions cut out of the inner body webs 30a, 30b by the cross-cutting. In this manner, double-ply bags 1 are successively manufactured.

[0036] An exemplary overlapping device 4 will be described below with reference to Figures 5, 6 and 7. Figure 6 collectively shows the views of arrows AA, BB, CC and DD in Figure 5.

[0037] The main web 2 for the outer body is unwound from an original roll 2', passes through the accumulator 80, and is fed in the forward horizontal direction X1 from the lower part of the accumulator 80. The inner body web 3 is unwound from an original roll 3', passes through the accumulator 80, and is fed in the forward horizontal direction X1 from the upper part of the accumulator 80. In this example, the original roll 2' for the outer body is formed by winding the web 2 so that the high melting point surface layer (base material layer) faces outward.

[0038] 5, the configuration related to the web 2 is shown in the BB and CC arrow views (webs 3, 30a, and 30b are omitted here). The overlapping device 4 includes a first slitter 41 for slitting the web 2 and dividing it into the above-mentioned two outer body webs 20a and 20b when the web 2 is fed in its longitudinal direction. The overlapping device 4 also includes a first guide mechanism 5 for guiding the web 2 to pass through the slitter 41 and guiding the webs 20a and 20b to the overlapping roller pair 40.

[0039] The first guide mechanism 5 includes a first upstream horizontal roller 50, a first inclined plate 51, a first upstream vertical roller 52, a first downstream vertical roller 53, a first separation guide member 54, and first and second downstream horizontal rollers 55,56.

[0040] The web 2 is redirected from the forward horizontal direction X1 to an upward direction Z1 by the upstream horizontal roller 50, then redirected to a second lateral direction Y2 by the triangular inclined plate 51, and further redirected back to the forward horizontal direction X1 by the upstream vertical roller 52. That is, in the view of the arrow BB in Fig. 6, the first guide mechanism 5 converts the surface of the web 2 being fed in the forward horizontal direction X1 from horizontal to vertical by these rollers 50-52.

[0041] Then, the web 2 is fed to the downstream vertical roller 53. In the section between the roller 52 and the roller 53, the high melting point surface layer of the web 2 faces in the second transverse direction Y2.

[0042] The web 2 passes through the downstream vertical roller 53, is converted from the forward horizontal direction X1 to the first transverse direction Y1, and is passed through the slitter 41. At this time, the web 2 is slit in the longitudinal direction at its center position by the slitter 41 to become the outer body webs 20a, 20b. The webs 20a, 20b are sent to a separation guide member 54.

[0043] The separation guide member 54 is an M-shaped guide plate in which two triangular inclined plates are joined. The outer body web 20a is redirected from the first horizontal direction Y1 to the upward direction Z1 by the separation guide member 54 and sent to the downstream horizontal roller 55. Meanwhile, the outer body web 20b is redirected from the first horizontal direction Y1 to the downward direction Z2 by the separation guide member 54 and sent to the downstream horizontal roller 56. Then, the downstream horizontal roller 55 redirects the upper web 20a to the forward horizontal direction X1 and changes its surface from vertical to horizontal. The downstream horizontal roller 56 redirects the lower web 20b to the forward horizontal direction X1 and changes its surface from vertical to horizontal.

[0044] In this manner, the first guide mechanism 5 guides the web 2 through the slitter 41, separates the two webs 20a, 20b into upper and lower parts, and makes the surfaces of the webs 20a, 20b horizontal. When the upper web 20a passes through the downstream horizontal roller 55, its high melting point surface layer is directed upward in the Z1 direction. When the lower web 20b passes through the downstream horizontal roller 56, its high melting point surface layer is directed downward in the Z2 direction.

[0045] Further, the first guide mechanism 5 includes a plurality of guide rollers 57 and a plurality of guide rollers 58. An appropriate number of guide rollers 57 / 58 are provided between the downstream horizontal roller 55 / 56 and the overlapping roller pair 40 to guide the web 20a / 20b to the overlapping roller pair 40 via the dancer roller 70a / 70b. Here, the first guide mechanism 5 keeps the webs 20a, 20b separated from each other by these rollers 55-58 until the webs 20a, 20b reach the overlapping roller pair 40, and forms a space 43 (FIG. 5) between the webs 20a and 20b. This space 43 is effectively utilized to form the inner body webs 30a, 30b and guide them to the overlapping roller pair 40.

[0046] The configuration related to the web 3 is shown in the AA and DD arrow views of Fig. 6 (webs 2, 20a, and 20b are omitted here). The overlapping device 4 includes a second slitter 42 for slitting the web 3 and dividing it into the above-mentioned two inner body webs 30a and 30b when the web 3 is fed in its longitudinal direction. The overlapping device 4 also includes a second guide mechanism 6 for guiding the web 3 to pass through the slitter 42 and guiding the webs 30a and 30b from the space 43 to the overlapping roller pair 40.

[0047] The second guide mechanism 6 includes a second upstream horizontal roller 60, a second inclined plate 61, a second upstream vertical roller 62, a second downstream vertical roller 63, a second separation guide member 64, third and fourth downstream horizontal rollers 65, 66, and midstream vertical rollers 690, 691.

[0048] The web 3 is redirected from the forward horizontal direction X1 to a downward direction Z2 by the upstream horizontal roller 60, then redirected to a first transverse direction Y1 by a triangular inclined plate 61, and further redirected back to the forward horizontal direction X1 by the upstream vertical roller 62. That is, in the view of arrow AA in Fig. 6, the second guide mechanism 6 converts the surface of the web 6 fed in the forward horizontal direction X1 from horizontal to vertical by these rollers 60-62.

[0049] Then, as shown in Fig. 7, the web 3 is sent to a midstream vertical roller 690, where it is redirected in a second transverse direction Y2, crosses between the two webs 20a, 20b, shifts to the Y2 side, and is redirected in a forward horizontal direction X1 by another midstream vertical roller 691. Then, the web 3 is sent to a downstream vertical roller 63 with its surface vertical. As shown in Fig. 7, the web 3 is detoured in the first transverse direction Y1 by the rollers 62, 690 from the first slitter 41 and the elements 50-56 of the first guide mechanism 5. That is, the rollers 62, 690 of the second guide mechanism 6 constitute detour rollers.

[0050] Then, the web 3 is converted from the forward horizontal direction X1 to a first transverse direction Y1 by the downstream vertical roller 63 and passed through the slitter 42. At this time, the web 3 is slit in the longitudinal direction at its central position by the slitter 42 to become the inner body webs 30a, 30b. The webs 30a, 30b are sent to a separation guide member 64.

[0051] The separation guide member 64 is an M-shaped guide plate similar to the separation guide member 54. The inner body web 30a is redirected from the first horizontal direction Y1 to the upward direction Z1 by the separation guide member 64 and sent to the downstream horizontal roller 65. Meanwhile, the inner body web 30b is redirected from the first horizontal direction Y1 to the downward direction Z2 by the separation guide member 64 and sent to the downstream horizontal roller 66. Then, the downstream horizontal roller 65 redirects the upper web 30a to the forward horizontal direction X1 and converts the surface from vertical to horizontal. The downstream horizontal roller 66 redirects the lower web 30b to the forward horizontal direction X1 and converts the surface from vertical to horizontal.

[0052] In this manner, the second guide mechanism 6 guides the web 3 through the slitter 42, separates the two webs 30a, 30b into upper and lower parts, and makes the surfaces of the webs 30a, 30b horizontal.

[0053] Further, the second guide mechanism 6 includes a plurality of guide rollers 67 and a plurality of guide rollers 68. An appropriate number of guide rollers 67 / 68 are provided between the downstream horizontal roller 65 / 66 and the overlapping roller pair 40 to guide the web 30a / 30b to the overlapping roller pair 40 via the dancer rollers 71a / 71b.

[0054] Therefore, the webs 20a-30b are overlapped with each other by the overlapping roller pair 40. The order is, from top to bottom, the first outer body web 20a, the first inner body web 30a, the second inner body web 30b, and the second outer body web 20b. At this time, the low melting point surface layer of the outer body web 20a contacts the inner body web 30a, and the low melting point surface layer of the outer body web 20b contacts the inner body web 30b.

[0055] The second slitter 42, the second separation guide member 64, the third and fourth downstream horizontal rollers 65, 66, and the guide rollers 67, 68 are disposed in the space 43 formed by the first guide mechanism 5. That is, these elements 42, 64-68 are spaced apart from the first separation guide member 54 in the forward horizontal direction X1, and are positioned below the first downstream horizontal roller 55 and above the second downstream horizontal roller 56. In this manner, by disposing the second slitter 42 and the elements 64-68 of the second guide mechanism 6 in the space 43 formed by the first guide mechanism 5, it is possible to overlap the four webs 20a-30b formed from the two original rolls 2', 3' on one another.

[0056] As described above, the overlapping device 4 slits the webs 2, 3 unwound from the two raw rolls 2', 3' into four webs 20a-30b, and overlaps these webs 20a-30b with each other by the overlapping roller pair 40. Therefore, a bag making machine equipped with this overlapping device 4 can process (e.g., heat seal) and cross-cut the four overlapped webs 20a-30b downstream of the overlapping roller pair 40, thereby making it possible to sequentially manufacture double-ply bags 1.

[0057] Conventional double-ply bag making requires a total of four original rolls, two for the outer body and two for the inner body. On the other hand, double-ply bag making according to the present invention requires only two original rolls, one for the outer body 2' and one for the inner body 3', because of the stacking device 4. This reduces the burden on the operator in replacing the original rolls, leading to improved work efficiency. In addition, reducing the number of original rolls from four to two reduces the space required for installing the original rolls, which can contribute to the miniaturization of the bag making machine as a whole.

[0058] In the above bag making, for the heat sealing process, the low melting point surface layers of the webs 20a, 20b must be brought into contact with the webs 30a, 30b by the overlapping roller pair 40. Therefore, it should be noted that when the webs 2, 20a, 20b are changed in direction by the elements of the first guide mechanism 5, the orientation of the high melting point surface layer / low melting point surface layer of the webs 2, 20a, 20b is also changed. In addition, it should be noted whether the first raw roll 2' is wound with the high melting point surface layer of the first main web 2 facing outward or inward.

[0059] Unlike the above example, when the webs 2 and 3 are not laminates but mono-materials, one side may be coated with a medium ink that inhibits heat sealing. In this way, the webs 2 and 3 are often generally defined to have a front and back.

[0060] Therefore, the guide mechanisms 5 and 6 may have additional elements or may have a configuration different from that illustrated above, but when carrying out bag making involving heat sealing, it is necessary to pay close attention to the conversion of the surface of the web by the elements of the guide mechanisms 5 and 6 and the front and back of the web. This can be easily understood by a person skilled in the art.

[0061] The illustrated main web 2 (outer body webs 20a, 20b) has a base material layer and a sealant layer. The base material layer is generally more resistant to scratches and friction than the sealant layer. Therefore, when the web 2, 20a or 20b is guided while generating frictional force against elements of the first guide mechanism 5 such as the first inclined plate 51 and the first separation guide member 54, it is preferable to bring the base material layer, rather than the sealant layer, into frictional contact with these elements.

[0062] As shown in the CC and DD arrow views of Fig. 6, as a result of the slitting, edges 200a, 200b, 300a, and 300b are generated in the webs 20a-30b, respectively. As shown in Fig. 7, the first and second guide mechanisms 5 and 6 make all of the edges 200a, 200b, 300a, and 300b face in the same direction (the second lateral direction Y2 in the embodiment) at the overlapping roller pair 40. Furthermore, as shown in Fig. 7, the first and second guide mechanisms 5 and 6 align these edges 200a-300b with each other when the webs 20a-30b are overlapped with each other by the overlapping roller pair 40.

[0063] The straightness of the edges on both sides of the main webs 2 and 3 is low due to the manufacturing process and transport process of the main web itself. On the other hand, as in the embodiment, the edges 200a-300b of the web that are created by the slit while being transported by the machine have high straightness and the passing position of the edges is stable. Therefore, by accurately aligning the edges 200a-300b, the accuracy of bag making (the processing required for bag making) is improved.

[0064] An exemplary configuration for this purpose will be described below. As shown in Fig. 8A, the overlapping device 4 may include a first position sensor 44 that detects the position in the width direction of the web 2 being fed, and an actuator 45 that finely adjusts the inclined plate 51 up and down.

[0065] As shown in Fig. 8C, the inclined plate 51 has an inclined edge 510 for changing the direction of the web 2. The web 2 engages with the inclined edge 510 and is folded back, thereby changing the direction with a reversal of the direction of its surface. As shown in the SS cross section of Fig. 8D, this inclined edge 510 is rounded to prevent damage to the web 2. Note that the inclined plate 61 and the separation guide members 54, 64 (M-shaped guide plates) also have similar inclined edges, which enable a smooth change in the direction of the web with a reversal of the direction of the surface.

[0066] In this example, the position sensor 44 detects the height of the edge of the web 2 at the first upstream vertical roller 52 for the main web 2 (where the edge of the web 2 extends horizontally). Alternatively, the position sensor 44 may detect the widthwise position of the web 2 by detecting a line-shaped mark applied to the web 2 by means of printing or the like. The position sensor 44 is an optical sensor. The actuator 45 moves the inclined plate 51 slightly up and down.

[0067] As is clear from FIG. 8B, when the inclined plate 51 descends, the web 2 also descends after passing the inclined edge 510 of the inclined plate 51 (see the arrow in FIG. 8B). At this time, the height of the edge (line-shaped mark) detected by the position sensor 44 also descends. Similarly, when the inclined plate 51 rises, the web 2 also rises, and the height of the detected edge also rises. Therefore, the overlapping device 4 can finely adjust the web 2 in its width direction (the height of the web 2) by finely moving the inclined plate 51 up and down using the actuator 45.

[0068] As described above, downstream, the web 2 is slit into two webs 20a, 20b by the slitter 41. Here, the slitter 41 is fixed. That is, the stacking device 4 (its one or more processors) can finely adjust the positions of the edges 200a, 200b generated by the slit by finely adjusting the inclined plate 51 up and down via the actuator 45 based on the detection of the position sensor 44.

[0069] The overlapping device 4 may also be provided with a position sensor 46 and an actuator 47 for the main web 3, as shown in FIG. 8E, to similarly fine-tune the positions of the edges 300a, 300b of the webs 30a, 30b.

[0070] In this example, the main webs 2 and 3 are slit by the slitters 41 and 42 after fine adjustment of the edges, so that the edges that will be located on the Y1 side are detected by the position sensors 44 and 46. Therefore, the edges detected by the position sensors 44 and 46 can be aligned with high accuracy on the Y1 side after slitting.

[0071] Furthermore, as described above, one edge of the main webs 2, 3 is detected by the position sensors 44, 46, respectively, and the positions are finely adjusted by the actuators 45, 47 based on the detection of the position sensors 44, 46, and then the main webs 2, 3 are slit by the slitters 41, 42 at the mechanically fixed positions. Therefore, after slitting, the edges 200a-300b generated by the slitting can also be aligned with high accuracy on the Y2 side.

[0072] Therefore, with this configuration, the overlapping device 4 can align the edges of the webs 20a-30b with one another with high precision, thereby enabling highly accurate bag production.

[0073] Although the Y1-side edges of the webs 20a-30b are finely adjusted, they may be slightly misaligned due to variations in the overall width dimensions of the main webs 2, 3. This problem may be solved in a subsequent process by slitting the webs 20a-30b along the Y1-side edges. Also, if the finely adjusted Y2-side edges 200a-300b may subsequently become misaligned, this may be adjusted by known means as necessary.

[0074] 9A and 9B, the positions of the edges 300a, 300b may be adjusted by moving the separation guide member 64, which is an M-shaped guide plate, in the horizontal directions Y1 and Y2 by the actuator 47 (see, for example, the arrows in FIG. 9B). Furthermore, although not shown, the positions of the edges 200a, 200b may be adjusted by moving the separation guide member 54 (as viewed in the direction of the CC arrow in FIG. 6) in the horizontal directions Y1 and Y2 by the actuator 45.

[0075] As described above, the bag making machine includes the first dancer roller 70a for engaging with the first outer body web 20a, the second dancer roller 70b for engaging with the second outer body web 20b, the third dancer roller 71a for engaging with the first inner body web 30a, and the fourth dancer roller 71b for engaging with the second inner body web 30b. The bag making machine switches from continuous feeding to intermittent feeding of these webs 20a-30b by these rollers 70a-71b.

[0076] Furthermore, as shown in FIG. 10, the bag making machine is equipped with a first link mechanism 90 for interlocking the first and second dancer rollers 70a, 70b, and a first biasing member 94 (e.g., a cylinder) for biasing the first and second dancer rollers 70a, 70b toward the webs 20a, 20b, respectively, via the first link mechanism 90.

[0077] The first link mechanism 90 includes two arms 91a, 91b that are substantially L-shaped and have the same shape as each other, each having a short portion and a long portion. The arms 91a, 91b are rotatable about pivot shafts 92a, 92b at their bent portions. The dancer roller 70a is rotatably supported at the tip of the long portion of the arm 91a, and the dancer roller 70b is rotatably supported at the tip of the long portion of the arm 91b. The tips of the short portions of the two arms 91a, 91b are connected to each other via a link 93. With this configuration of the first link mechanism 90, the dancer rollers 70a, 70b are capable of moving the same distance and in the same direction as each other.

[0078] Further, the first biasing member 94 biases the arms 91a, 91b toward the first and second outer body webs 20a, 20b (counterclockwise in FIG. 10) to apply tension to the first and second outer body webs 20a, 20b.

[0079] For example, even if the upper outer body web 20a engaged with the dancer roller 70a becomes loose, the two arms 91a, 91b (and therefore the dancer rollers 70a, 70b) rotate in unison (counterclockwise in FIG. 10) by the first biasing member 94, thereby forcibly stretching the lower outer body web 20b and eliminating the slack in the outer body web 20a. As a result, the line pass length of the outer body web 20a and the pass line length of the outer body web 20b become the same.

[0080] The webs 20a, 20b are formed by slits in one main web 2, and theoretically have the same length. However, in reality, the pass line lengths of both webs may change during feeding due to factors such as the thickness of the main web 2 being non-uniform in its width direction. As described above, the link mechanism 90 and the biasing member 94 keep the pass line lengths of both webs the same, and therefore this problem can be solved.

[0081] The bag making machine includes a second link mechanism 95 for interlocking the third and fourth dancer rollers 71a, 71b, and a second biasing member 99 (e.g., a cylinder) for biasing the third and fourth dancer rollers 71a, 71b toward the webs 30a, 30b via the second link mechanism 95. The second link mechanism 95 includes arms 96a, 96b, rotating shafts 97a, 97b, and a link 98. The configurations of the second link mechanism 95 and the second biasing member 99 are the same as the configurations of the first link mechanism 90 and the first biasing member 94, and therefore the lengths of the pass lines of both webs 30a, 30b are made the same.

[0082] 11, an additional first dancer roller 70c and an additional second dancer roller 70d may be rotatably supported on arms 91a, 91b of the first link mechanism 90. The webs 20a, 20b are wound around the dancer rollers 70a, 70b, one of the multiple guide rollers 57, 58 (the above-mentioned guide rollers for guiding the webs 20a, 20b to the overlapping roller pair 40) whose positions are fixed, and the additional dancer rollers 70c, 70d, in that order. This makes it possible to reduce the swing amplitude of the arms 91a, 91b.

[0083] Similarly, an additional third dancer roller 71c and an additional fourth dancer roller 71d may be rotatably supported on the arms 96a, 96b, respectively, of the second link mechanism 95. The webs 30a, 30b are wound around the dancer rollers 71a, 71b, one of the multiple position-fixed guide rollers 67, 68 (the above-mentioned guide rollers for guiding the webs 30a, 30b to the overlapping roller pair 40), and the additional dancer rollers 71c, 71d, respectively, in that order. This makes it possible to reduce the oscillation amplitude of the arms 96a, 96b.

[0084] Generally, mono-materials such as polyethylene and polypropylene have lower rigidity and higher elasticity than laminate materials, so when a mono-material web is used, the expansion and contraction range increases as the oscillation amplitude of the dancer roller increases. When the webs 20a, 20b / 30a, 30b are mono-materials, such expansion and contraction causes a large fluctuation in the frictional force generated when the webs 20a, 20b / 30a, 30b pass through the separation guide members 54 / 64 (FIG. 6), which may hinder smooth transport.

[0085] The configuration of FIG. 11 can suppress the swing amplitude of the arms 91a, 91b / 96a, 96b, thereby suppressing the above-mentioned fluctuation in frictional force, and as a result, can provide smooth transportation of the webs 20a, 20b / 30a, 30b.

[0086] 11 can suppress the oscillation amplitude of the arms 91a, 91b, 96a, and 96b even if the intermittent conveying pitch of the webs 20a-30b downstream of the dancer rollers 70a-71d is large, thereby ultimately suppressing the fluctuation of the tensile stress applied to the webs 20a-30b, suppressing the expansion and contraction width of the webs 20a-30b, and providing smoother conveyance of the webs 20a-30b.

[0087] It is preferable that the inertia of the arms 91a, 91b, 96a, and 96b is small, and therefore it is preferable that the arms are made of a light material such as carbon.

[0088] Other exemplary first and second guide mechanisms 5, 6 that enable the above-described bag making will be described below. The same or similar components are designated by the same reference numerals.

[0089] 12A, 12B, and 13 show another exemplary overlapping device 4. In this example, the midstream vertical rollers 690, 691 (FIG. 7) of the previous example are not provided. The downstream vertical roller 63 is disposed on the Y1 side, not on the Y2 side. The upstream vertical roller 62 and the downstream vertical roller 63 function as bypass rollers to bypass the web 3 in the first transverse direction Y1 so as not to interfere with the slitter 41 and the elements 50-56 of the first guide mechanism 5. The web 3 is redirected from the forward horizontal direction X1 to the second transverse direction Y2 by the downstream vertical roller 63 and passed through the slitter 42 (as viewed by the arrow DD in FIG. 13). In this example, the edges 200a, 200b and the edges 300a, 300b are not aligned with each other at the overlapping roller pair 40.

[0090] 14A, 14B, and 15 show yet another exemplary stacking device 4. As seen from the AA arrow in FIG. 15, the orientation of the inclined plate 61 in this example is opposite to that seen from the AA arrow in FIG. 6, and the main web 3 is redirected in the second transverse direction Y2. The upstream vertical roller 62 and the downstream vertical roller 63 are both disposed on the Y2 side, not on the Y1 side, thereby constituting a detouring roller that detouring the web 3 further outward than the web 2 and in the second transverse direction Y2 to guide the web 3 to the slitter 42 so as not to interfere with the slitter 41 and the elements 50-56 of the first guide mechanism 5.

[0091] 16A, 16B, and 17 show another example of the overlapping device 4. As shown in FIG. 16A and FIG. 16B, this example is different from the above-mentioned examples in that the raw roll 2' for the outer body is arranged on the upper side, and the raw roll 3' for the inner body is arranged on the lower side. Furthermore, the raw roll 2' is wound with the main web 2 so that the high melting point surface layer faces inward. The web 2 is redirected from the forward water direction X1 to the downward direction Z2 by the upstream horizontal roller 50, redirected to the second transverse direction Y2 by the inclined plate 51, and then redirected to the forward horizontal direction X1 by the upstream vertical roller 52 and sent to the downstream vertical roller 53. This also allows the low melting point surface layers of the webs 20a, 20b to come into contact with the webs 30a, 30b, respectively, when the webs 20a-30b are overlapped with each other by the overlapping roller pair 40, as in the above-mentioned other examples.

[0092] The stacking device 4 is applicable to the production of any type of double-layered bag, not limited to the production of the simple double-layered bag 1 of Fig. 1A. For example, it is obvious to a person skilled in the art that the stacking device 4 may be incorporated into a bag making machine for double-layered bags that includes additional elements such as a zipper, a gusset, etc. instead of or in addition to the spout 15. [Explanation of symbols]

[0093] 1 double bag 11 First and second outer body sections 12 First and second inner bodies 2 First Main Web 2' First roll 20a, 20b First and second outer body webs 3 Second Main Web 3' 2nd roll 30a, 30b First and second inner body webs 4 Web stacking device 40 Stacking roller pair 41 First Slitter 42 No. 2 Slitter 5 First guide mechanism 53 First downstream vertical roller 54 First separation guide member 55 First downstream horizontal roller 56 Second downstream horizontal roller 6 Second guide mechanism 63 Second downstream vertical roller 64 Second separation guide member 65 3rd downstream horizontal roller 66 Fourth downstream horizontal roller 62,63,690 Detour Roller 70a, 70b, 71a, 71b 1st, 2nd, 3rd and 4th dance rollers 82,83 Sealing device 84 Feeder 85 Crosscut device 90 First link mechanism 94 First biasing member 95 Second link mechanism 99 Second biasing member

Claims

1. A bag making machine configured to sequentially produce double-layered bags, The double-layered bag includes a first outer body portion, a second outer body portion, a first inner body portion, and a second inner body portion, the first and second inner body portions facing each other and being interposed between the first and second outer body portions, The bag making machine comprises: a first slitter for slitting a first main web unwound from a first roll into a first outer body web for the first outer body portion and a second outer body web for the second outer body portion when the first main web is fed; a second slitter for slitting the second main web unwound from the second roll into a first inner body web for the first inner body portion and a second inner body web for the second inner body portion when the second main web is fed; A pair of stacking rollers; a first guide mechanism that guides the first main web through the first slitter and guides the first and second outer body webs to the pair of overlapping rollers, the first guide mechanism separating the first and second outer body webs from each other until the first and second outer body webs reach the pair of overlapping rollers to form a space between the first outer body web and the second outer body web; a second guide mechanism that guides the second main web through the second slitter and guides the first and second inner body webs from the space to the overlapping roller pair so that the first outer body web, the second outer body web, the first inner body web, and the second inner body web are overlapped with each other by the overlapping roller pair; a first dancer roller for engaging the first outer body web upstream of the overlapping roller pair to switch the first outer body web from continuous feeding to intermittent feeding; a second dancer roller for engaging the second outer body web upstream of the overlapping roller pair to switch the second outer body web from continuous feeding to intermittent feeding; a first link mechanism for interlocking the first and second dancer rollers with each other; a first biasing member for biasing the first and second dancer rollers toward the first and second outer body webs, respectively, via the first link mechanism. Bag making machine.

2. the overlapping roller pair is spaced apart from the first and second webs in a forward horizontal direction, The first guide mechanism includes: A first separation guide member for redirecting the first outer body web from a lateral direction perpendicular to the forward horizontal direction to an upward direction and the second outer body web from the lateral direction to a downward direction; A first downstream horizontal roller provided downstream of the first separation guide member for redirecting the first outer body web from an upward direction to the forward horizontal direction; a second downstream horizontal roller provided downstream of the first separation guide member for changing the direction of the second outer body web from the downward direction to the forward horizontal direction; The second guide mechanism includes: A second separation guide member for redirecting the first inner body web from the lateral direction to an upward direction and the second inner body web from the lateral direction to a downward direction; A third downstream horizontal roller is provided downstream of the second separation guide member and serves to change the direction of the first inner body web from the upward direction to the forward horizontal direction; a fourth downstream horizontal roller provided downstream of the second separation guide member for changing the direction of the second inner body web from the downward direction to the forward horizontal direction; 2. The bag making machine according to claim 1.

3. the second slitter and the second separation guide member are spaced apart from the first separation guide member in the forward horizontal direction and are located below the first downstream horizontal roller and above the second downstream horizontal roller; 3. The bag making machine according to claim 2.

4. the third and fourth downstream horizontal rollers are spaced apart from the first separation guide member in the forward horizontal direction and are positioned below the first downstream horizontal roller and above the second downstream horizontal roller; 4. The bag making machine according to claim 3.

5. the second guide mechanism further includes a plurality of diverting rollers for diverting the second main web in the lateral direction from the first slitter and the first separation guide member; 3. The bag making machine according to claim 2.

6. the first guide mechanism further comprises a first downstream vertical roller for redirecting the first main web from the forward horizontal direction to the lateral direction through the first slitter; the first slitter is positioned to slit the first main web being fed in the transverse direction through the first downstream vertical roller; 3. The bag making machine according to claim 2.

7. the second guide mechanism further comprises a second downstream vertical roller for redirecting the second main web from the forward horizontal direction to the lateral direction through the second slitter; the second slitter is positioned to slit the second main web being fed in the transverse direction through the second downstream vertical roller; 7. The bag making machine according to claim 6.

8. the first and second guide mechanisms are configured to guide the first and second outer body webs and the first and second inner body webs such that edges formed by slits in the first and second outer body webs and the first and second inner body webs all face the same direction when the first and second outer body webs and the first and second inner body webs are overlapped.

2. The bag making machine according to claim 1.

9. The web feeder further includes a feed device provided downstream of the overlapping roller pair and intermittently feeds the first and second outer body webs and the first and second inner body webs.

2. The bag making machine according to claim 1.

10. a third dancer roller for engaging the first inner cylinder web upstream of the overlapping roller pair to switch the first inner cylinder web from continuous feeding to intermittent feeding; a fourth dancer roller for engaging the second inner cylinder web upstream of the overlapping roller pair to switch the second inner cylinder web from continuous feeding to intermittent feeding; a second link mechanism for interlocking the third and fourth dancer rollers with each other; a second biasing member for biasing the third and fourth dancer rollers toward the first and second inner body webs, respectively, via the second link mechanism.

2. The bag making machine according to claim 1.

11. a feed device provided downstream of the overlapping roller pair for intermittently feeding the first and second outer body webs and the first and second inner body webs; a sealing device provided downstream of the pair of overlapping rollers for heat-sealing the first and second outer body webs and the first and second inner body webs; a cross-cutting device provided downstream of the sealing device and cross-cutting the first and second outer body webs and the first and second inner body webs in the width direction at each intermittent feed to form the double bag.

2. The bag making machine according to claim 1.

Images