Transverse cutting device, bag making machine and transverse cutting method
By using the up-down and horizontal movement mechanisms of the tool pair in the cross-cutting device, the problem of difficulty in removing residue during the shearing process is solved, and efficient shearing of the material sheet and improving the quality of the bag are achieved.
Patent Information
- Application Number
- CN202380038318.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-05-10
- Filing Date
- 2023-03-15
- Publication Date
- 2024-12-13
AI Technical Summary
In the prior art, the residue generated by the cross-cutting device accompanied by two shearing is difficult to effectively remove, which may cause foreign matter to be mixed into the bag, affecting the quality and safety of the bag.
A cross-cutting device is designed, including a tool pair, an up-down moving device and a horizontal moving device, by moving the tool pair from a more upstream position to a first position during the second shear and reaching a minimum height at the upper tool. Then start moving, ensuring that the piece can pass through between the tools, thereby removing residue.
Effectively removes residues generated by the second shear, preventing them from adhering to the bag, improving the quality and safety of the bag, simplifying the bag making process, and reducing the risk of foreign matter mixing.
Smart Images
Figure CN119136971A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a cross-cutting device for shearing a material sheet, and a bag making machine comprising the cross-cutting device. In addition, the present application relates to a cross-cutting method for shearing a material sheet for bag making. Background Art
[0002] The bag making machine includes, for example, an intermittent conveying device that intermittently conveys the material sheet along its length direction; a processing device that processes the material sheet during the period of stopping the intermittent conveying; and a cross-cutting device that cuts the processed material sheet along its width direction to form a bag during the period of stopping the intermittent conveying.
[0003] The processing device is, for example, a heat sealing device that heat seals the web in the width direction and / or the length direction of the web, and / or a punching device that punches the web so that the formed bag has a cut corner portion.
[0004] In the case of a bag with sharp corners, the user may be injured by the corners. On the other hand, the corner cut portion, for example, has a rounded shape, which can prevent injuries. In addition, the corner cut portion can improve the appearance of the bag.
[0005] The cross-cutting device is arranged downstream of the processing device. The cross-cutting device typically uses a pair of knives including an upper knife and a lower knife to shear the web.
[0006] There are two types of cross cutting: one with only one shearing and one with two shearings. In the former case, if the cutting position is offset, a protrusion will be generated at the cutting corner (for example, as described in Patent Document 1). Fig.13 B symbol 170a). This may make the bag unsightly and may also cause injury.
[0007] In the latter case, the generation of protrusions can be prevented (see, for example, Patent Document 2). Fig.11 Specifically, the latter uses the knife pair to shear the web (first time), moves the knife pair upstream, uses the knife pair to shear the web again (second time), and then moves the knife pair downstream again to return to the original position.
[0008] Cross-cutting with two shearing steps can prevent the generation of protrusions. On the other hand, residues are inevitably generated during the second shearing step. If such residues are not separated from the sheet properly, the residues may adhere to the formed bag, which may cause the problem of foreign matter mixing.
[0009] Prior art literature
[0010] Patent Literature
[0011] Patent Document 1: WO2019 / 123875
[0012] Patent Document 2: WO2019 / 163496 Summary of the invention
[0013] The purpose of the present application is to reliably keep the residue generated by the cross-cutting accompanied by the double shearing away from the web.
[0014] The present application provides a cross-cutting device for bag making, which is used to shear a material sheet twice during a pause period of intermittent conveying.
[0015] The cross-cutting device comprises:
[0016] Tool pair, including upper and lower knives;
[0017] A conveying device, used for intermittently conveying the sheet along the length direction of the sheet;
[0018] an up-and-down moving device, used to reciprocate the upper knife up and down relative to the lower knife in order to shear the sheet; and
[0019] The horizontal moving device moves the pair of cutters horizontally between a first position for the first shearing and a second position which is further upstream than the first position and is for the second shearing.
[0020] The horizontal moving device is configured to move the knife pair from the second position to the first position from after the upper knife reaches the lowest height to before exceeding the shearing height during the reciprocating movement of the upper knife for the second shearing.
[0021] The conveying device is configured to start conveying the web after the pair of cutters starts moving from the second position to the first position.
[0022] The conveying device may be configured as follows:
[0023] In the reciprocating movement of the upper knife for the second shearing, the web is conveyed before the upper knife exceeds the shearing height, and after the upper knife exceeds the shearing height, the web is passed through the space between the upper knife and the lower knife.
[0024] The conveying device may be configured as follows:
[0025] During the reciprocating movement of the upper knife for the second shearing, the web starts to be conveyed after the upper knife exceeds the shearing height and before it reaches the maximum height.
[0026] In addition, the present application provides a bag-making machine that manufactures bags sequentially from at least one sheet of material and includes the cross-cutting device.
[0027] The bag making machine may include a punching device, which is provided upstream of the cross-cutting device and is used to punch the web at each intermittent transfer.
[0028] The blanking device may include:
[0029] A first punching blade for forming a hole or a cutout for a corner cutting portion on the sheet; and
[0030] The second punching blade is used to form a hole for a notch on the material sheet at a position away from the hole or the notch for the corner cutting portion along the width direction of the material sheet.
[0031] The cross-cutting device may be configured to use the pair of cutters to shear the material sheet in the width direction of the material sheet in a manner transverse to the hole or cutout for the corner cutting portion and the hole for the notch, thereby forming the bag having the notch and the corner cutting portion.
[0032] In addition, the present application provides a cross-cutting method for forming bags by shearing a web using a pair of cutters including an upper knife and a lower knife.
[0033] The method comprises:
[0034] (a) temporarily stopping the conveyance of the web;
[0035] (b) during step (a), the upper knife is reciprocated up and down relative to the lower knife, thereby shearing the web along the width direction of the web at a first position;
[0036] (c) during step (a), subsequent to step (b), moving the pair of tools from the first position to a second position further upstream than the first position;
[0037] (d) following step (c), the upper knife is moved reciprocally up and down relative to the lower knife again to shear the web along the width direction of the web at the second position;
[0038] (e) in step (d), after the upper knife reaches the lowest height and before it exceeds the shearing height, the knife pair is moved from the second position to the first position; and
[0039] (f) After the step (e), the web is conveyed along the length direction of the web.
[0040] In the step (f), the material sheet may be conveyed before the upper knife exceeds the shearing height in the step (d), and the material sheet may be passed through the space between the upper knife and the lower knife after the upper knife exceeds the shearing height.
[0041] In the step (f), the web may be conveyed after the upper knife exceeds the shearing height in the step (d) and before reaching the maximum height.
[0042] The web may include a sealant layer. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] [ Figure 1 ] Figure 1 It is a schematic side view showing a downstream portion of an exemplary bag making machine.
[0044] [ Figure 2 ] Figure 2 It is a schematic plan view showing the processed sheet and bag.
[0045] [Figure 3] Figure 3A Indicates the tip of the punch knife used for cutting corners. Figure 3B Indicates the tip of the punch knife used for notching.
[0046] [Figure 4] Figure 4A A cross-cutting (comparative example) with a single shear is illustrated. Figure 4B A cross cut with two shears is exemplified.
[0047] [Figure 5] Figure 5A is a schematic plan view of an exemplary cross-cutting device. Figure 5B This is a schematic plan view of the vertical moving device and the horizontal moving device.
[0048] [Figure 6] Fig. 6A This is a schematic diagram of the sliding guide. Figure 6B This is a schematic diagram of the crank mechanism of the up and down moving device.
[0049] [Figure 7] Fig. 7A , Figure 7B They represent the tool pairs shown as examples, Figure 7C yes Figure 7B A magnified view of region T, Fig.7D yes Figure 7C SS line profile.
[0050] [Figure 8] Fig. 8A This is a schematic diagram of the guide structure. Figure 8B yes Fig. 8A Schematic side view of .
[0051] [ Fig. 9 ] Fig. 9 It is a magnified representation Figure 5B A schematic diagram of area T.
[0052] [ Fig.10 ] Fig.10is a block diagram of an exemplary transverse cutting device.
[0053] [ Fig.11 ] Fig.11 An exemplary cross-cutting process performed by a cross-cutting device is shown.
[0054] [ Fig.12 ] Fig.12 A timing diagram showing an example of a transverse cutting device.
[0055] [ Fig.13 ] Fig.13 is a timing chart showing a comparative example.
[0056] [Figure 14] Fig.14A The knife pair is illustrated when the upper knife is at the shear height. Fig. 14B 2 is a diagram for explaining an example of the timing of starting the conveyance of the web 1. Fig. 14C yes Fig. 14B Magnified view of area T.
[0057] [Figure 15] Figures 15A to 15C An exemplary cross-cutting step is shown.
[0058] [Figure 16] FIG. 16A to FIG. 16D The cross-cutting step of the comparative example is shown. DETAILED DESCRIPTION
[0059] Hereinafter, the embodiments of the present application will be described with reference to the accompanying drawings. The following are merely examples of the present application.
[0060] Figure 1 Indicates the downstream part of the illustrated bag making machine. In the upstream section of the bag making machine, the material sheet 1 is drawn out from a roll material not shown in the figure. In the downstream section of the bag making machine, the material sheet 1 is intermittently conveyed along its length direction. Therefore, the material sheet 1 is repeatedly conveyed and temporarily stopped. Its conveying direction is represented by the symbol X1. In the embodiment, two pieces of material 1 are intermittently conveyed in a state of overlapping each other. Alternatively, a piece of material 1 in a folded state may be intermittently conveyed.
[0061] In an embodiment, the web 1 is a laminated film in which one side is composed of a substrate and the other side is composed of a sealant. Alternatively, the web 1 may include a substrate of paper and a resin at least partially coated on the substrate. Alternatively, the web 1 may also be composed of a single material.
[0062] The bag making machine comprises: a cross-cutting device 3 for cutting the material sheet 1 along its width direction Y ( Figure 2 ) to form a bag 10; and a processing device 2, which is arranged upstream of the cross-cutting device 3 and processes the material sheet 1 during each intermittent conveyance. The processing device 2 includes a heat sealing device 20, a punching device 21 and a slitting machine 22.
[0063] The heat sealing device 20 heat seals the sheet 1 at each intermittent feeding. For example, the heat sealing device 20 includes: a longitudinal heater 200, which heat seals the sheet 1 along its length direction X to form a longitudinal sealing portion 11 ( Figure 2 ) and a transverse heater 201, the sheet 1 is heat-sealed along its width direction Y to form a transverse sealing portion 12 ( Figure 2 ). These heaters 200, 201 include, for example, heat sealing bars.
[0064] The blanking device 21 blanks the material sheet 1 at each intermittent feeding. For example, the blanking device 21 includes: a blanking knife 210, which is used to blank the material sheet 1, and form a blank on the material sheet 1. Figure 2 and a punching knife 211 for punching the sheet 1, and forming a hole 13 and / or a cutout 14 for the corner cutting portion 16; Figure 2 The holes 15 for the notches 17 are provided. The punching knives 210 and 211 are provided with receiving knives 212 and 213, respectively. Figure 2 Thus, the hole 15 for the notch 17 is formed in the web 1 at a position away from the hole 13 for the corner cut 16 and the notch 14 in the width direction Y of the web 1. Residue (not shown) generated by punching is removed by suction or the like.
[0065] like Figure 3A In this way, the tip of the punching blade 210 substantially has a ring shape formed by connecting four arc-shaped cutting corners 16. Figure 3B In this way, the blade tip of the punching blade 211 is substantially in the shape of two connected notches 17 and has a substantially rhombus shape.
[0066] The slitting machine 22 is disposed, for example, at the center of the web 1 in the width direction Y. The web 1 is cut in the longitudinal direction X by the slitting machine 22 as the web 1 is fed.
[0067] The cross-cutting device 3 shears the web 1 in the width direction Y at each intermittent conveyance to form a bag 10 from the web 1. The embodiment is a so-called two-row bag making. That is, Figure 2 In that way, in each cycle of cross-cutting, two bags 10 are formed.
[0068] As will be described later, the cross-cutting device 3 shears the web 1 twice during the stop period of the intermittent conveyance. Figure 2 In this way, the portion cut from the web 1 in the first shearing forms the bag 10. The main body of the bag 10 is formed by the web 1. The portion cut from the web 1 in the second shearing is the residue 18.
[0069] The cross-cutting device 3, for example, shears the material sheet 1 in the width direction Y in a manner that crosses the hole 13, the hole 15, and the notch 14. In this case, the bag 10 has a corner cut 16 and a notch 17. The arc-shaped corner cut 16 is located at the four corners of the rectangular bag 10 to help prevent injuries. The notch 17 is located at both side edges of the bag 10 to facilitate opening of the bag 10. In an embodiment accompanied by corner cutting and notch processing, the residue 18 includes micro-residues 180.
[0070] exist Figure 4A In the case of a single shearing, if the material sheet 1 is cut at the line L1 deviating from the regular cutting line Lr, the bag 10 will have a protrusion 19, and there is a possibility of damage by the protrusion 19. Figure 4B In the case of double shearing, if the material sheet 1 is sheared at two locations, line L2 and line L3, the generation of protrusions can be avoided. For the above reasons, the cross-cutting device 3 shears the material sheet 1 twice in one cycle of cross-cutting. However, if it is sheared twice, the generation of residue 18 is inevitable.
[0071] like Figure 1 In this way, the cross-cutting device 3 includes a conveying device 4 for intermittently conveying the web 1 along the direction X1. The conveying device 4 includes two conveying rollers 40 and an actuator 41 (e.g., a motor). At least one of the conveying rollers 40 is connected to the actuator 41 in an operable manner. If the conveying rollers 40 holding the web 1 are intermittently rotated by the actuator 41, the web 1 is intermittently conveyed.
[0072] The cross-cutting device 3 includes a pair of cutters 5 provided downstream of the conveying rollers 40. The pair of cutters 5 includes an upper cutter 50 and a lower cutter 51 for shearing the web 1.
[0073] The cross-cutting device 3 includes: an up-and-down moving device 6 ( Figure 5B , Figure 6B ), used for Fig.11 As shown, the upper knife 50 is reciprocated up and down relative to the lower knife 51; and the horizontal moving device 7 ( Figure 5B ) is used to move the tool pair 5 upstream (direction X2) and downstream (direction X1).
[0074] like Figure 5A As schematically shown in FIG. 1 , the tool pair 5 and the devices 6 and 7 are unitized and mounted on a main frame 30 .
[0075] For example, a crank mechanism can be used as the up and down moving device 6. Figure 5B In this way, the slide frame 60 is arranged on both sides of the upper knife 50. Fig. 6A In this way, the sliding frame 60 has a guide groove 600 extending up and down. Figure 6BIn this way, the slide pin 61 is provided on the upper and lower sides of both side surfaces of the upper blade 50. The slide pin 61 is supported by the guide groove 600 in a manner that allows it to slide along the guide groove 600. Thus, the upper blade 50 can move up and down along the guide groove 600. In addition, the slide pin 61 is urged upstream (direction X2) by an urging member (not shown) such as a spring.
[0076] The crank shaft 62 is rotatably supported on the main frame 30. An elliptical crank 63 is mounted on the end of the crank shaft 62 and is rotatable together with the crank shaft 62. The connecting rod 64 is connected to the front end of the crank 63 via a crank pin 65 at its first end (lower end). The connecting rod 64 is connected to the upper knife 50 via a lower sliding pin 61 at its second end (upper end). Furthermore, the crank shaft 62 is connected to an actuator 66 such as a motor in an operable manner. Therefore, if the crank shaft 62 is rotated by the actuator 66, the upper knife 50 reciprocates up and down. In this way, the up and down moving device 6 moves the upper knife 50 between the top dead center (highest height) and the bottom dead center (lowest height).
[0077] Fig. 7A FIG. 5 is a view of the tool pair 5 in the direction X2 as an example, and the upper tool 50 is located at the top dead center. The straight blade tip 500 of the upper tool 50 is inclined relative to the vertical direction and the horizontal direction Y. The upper tool 50 is inclined at one side (at the Fig. 7A The upper blade 50 is located just downstream of the lower blade 51 (see the right side in the figure). The upper blade 50 is located just downstream of the lower blade 51 (see the right side in the figure). The upper blade 50 is located just downstream of the lower blade 51 (see the right side in the figure). The upper blade 50 is located just downstream of the lower blade 51 (see the right side in the figure). Figure 1 ), and is urged in the upstream direction X2 by the urging member as described above. Therefore, the knife pair 5 shears (crosscuts) the web 1 while the upper knife 50 is always urged against the lower knife 51 and abuts against it. This provides good shearing.
[0078] Figure 7B Another example of a tool pair 5 is shown. Figure 7C yes Figure 7B A magnified view of region T, Fig.7D yes Figure 7C In the example, if Figure 7B In this way, when the upper blade 50 is at the top dead center, it does not overlap with the lower blade 51. The lower blade 51 has a triangular inclined surface 510 at one corner corresponding to the lowermost end of the upper blade 50. When the upper blade 50 descends, the blade surface facing upstream thereof straddles the inclined surface 510, thereby reliably shearing (cross-cutting) the sheet 1. In the above example, if the sheet 1 is away from the inclined surface 510 (i.e., not more than rightward), Figure 7C Position R) and intermittent conveyance between the upper knife 50 and the lower knife 51 will not cause shearing defects.
[0079] Next, the horizontal moving device 7 is described. Figure 5B , Fig. 6A In this way, the sliding beam 70 is supported at both ends by the sliding frame 60. The fixed beam 71 is supported at both ends by the support frame 72 fixed to the main frame 30. The sliding beam 70 and the fixed beam 71 extend in the Y direction.
[0080] The sliding frame 60 and the sliding beam 70 can move as a whole in a small interval along the direction X. For example, a track structure can be adopted. Fig. 8A , Figure 8B In this way, the rail 73 is mounted on the main frame 30 and extends in the direction X. The guide roller 74 is rotatably supported on the slide frame 60 and sandwiches the rail 73 .
[0081] As shown in FIG5 , the slide beam 70 and the fixed beam 71 are connected to each other via a transmission shaft 75 extending in the direction X. Fig. 9 Thus, the transmission shaft 75 is supported by the fixed beam 71 so as to be rotatable and non-displaceable in the direction X. A part of the transmission shaft 75 is configured as a feed screw 750 . An internal thread (not shown) is formed inside the slide beam 70 and engages with the feed screw 750 .
[0082] The transmission shaft 75 is connected to the actuator 76 in an operable manner. As the actuator 76, for example, a motor disposed on the fixed beam 71 can be used. In addition, the transmission shaft 75 is connected at its end to a bevel gear 77 mounted on the output shaft 760 of the motor 76. Therefore, when the transmission shaft 75 is rotated by the actuator 76, the slide frame 60 and the slide beam 70 move in the direction X.
[0083] Although not shown, the lower knife 51 is directly or indirectly mounted on the slide frame 60 , and is movable in the direction X together with the slide frame 60 and the slide beam 70 .
[0084] Therefore, when the transmission shaft 75 is rotated by the actuator 76 , the pair of cutters 5 (the upper cutter 50 and the lower cutter 51 ) moves in the direction X.
[0085] The devices 6 and 7 are merely examples. Any structure may be used as these devices 6 and 7. For example, the motor 76 as an actuator and the bevel gear 77 may be connected via a gear train instead of being directly connected. The transmission shaft 75 with the bevel gear 77 may be built into the fixed beam 71. The two transmission shafts 75 may be arranged at intervals along the direction Y, so that the horizontal movement of the tool pair 5 can be more reliably performed. In this case, the two transmission shafts 75 are configured to be connected to the actuator 76 in an operable manner via a transmission structure including a bevel gear, a gear train, etc., and rotate synchronously.
[0086] like Fig.10As shown, the cross-cutting device 3 includes a control unit 31 (processor, controller, etc.) electrically connected to the actuator 41, the actuator 66, and the actuator 76. The control unit 31 controls the actuator 41, the actuator 66, and the actuator 76 (thus, the device 4, the device 6, and the device 7) to implement the cross-cutting process. Fig.11 , Fig.12 The cross-cutting process exemplified in FIG.
[0087] First, the conveying device 4 temporarily stops conveying the web 1 .
[0088] After a predetermined time from the temporary stop of the conveyance, the cross-cutting device 3 shears the web 1 at the first position P1 (for the first time). Therefore, the up-down moving device 6 causes the upper knife 50 of the knife pair 5 located at the first position P1 to descend from the upper dead center (highest position) to the lower dead center (lowest position), and then to ascend from the lower dead center and return to the upper dead center. The web 1 is sheared in the width direction Y of the web 1 by the upper knife 50 and the lower knife 51 at the first position P1 (refer to Fig.11 (1), (2)) The bag 10 is formed by the first shearing and is transported downstream by a conveyor (not shown).
[0089] Then, the cross-cutting device 3 shears the sheet 1 at the second position P2 (second time). First, the horizontal moving device 7 moves the knife pair 5 (upper knife 50 and lower knife 51) from the first position P1 upstream to the second position P2 ( Fig.11 (3)). Thereafter, the up-down moving device 6 lowers the upper knife 50 from the upper dead point to the lower dead point at the second position P2, and the upper knife 50 and the lower knife 51 shear the sheet 1 ( Fig.11 (4)) The upper knife 50 is raised from the lower dead point and returned to the upper dead point.
[0090] Due to the second shearing, the residue 18 is inevitably generated. The width of the residue 18 is equivalent to the distance D between the first position P1 and the second position P2. As described above, the micro-residues 180 are generated in the embodiment due to the chamfering process and the notch process.
[0091] During the reciprocating movement of the upper knife 50 for the second shearing, at the time when the upper knife 50 reaches the bottom dead center or after the upper knife 50 reaches the bottom dead center, the horizontal moving device 7 moves the knife pair 5 downstream (along the direction X1) from the second position P2 and starts to return to the first position P1 ( Fig.11 (4)(5)). Specifically, the horizontal moving device 7 enables the knife pair 5 to start moving to the first position P1 after the upper knife 50 reaches the bottom dead center and before it exceeds the shearing height h. More specifically, as Fig.12 As shown, the horizontal moving device 7 starts moving the upper knife 50 from the second position P2 to the first position P1 while the upper knife 50 stays at the bottom dead center.
[0092] Here, the “shear height h” is shown in Fig.14A The shear height h is 50 degrees. Fig.14A The height at which the web 1 is sheared and finished is shown. In other words, the shearing height h of the upper blade 50 is the height at the time point when the upper blade 50 just blocks the conveying path through which the web 1 passes.
[0093] Furthermore, the horizontal moving device 7 moves the knife pair 5 to the first position P1 and ends (returns and ends) before the upper knife 50 reaches the top dead center or at the time when the upper knife 50 reaches the top dead center. Specifically, the horizontal moving device 7 of the embodiment returns the knife pair 5 to the first position P1 and ends (returns and ends) before the upper knife 50 exceeds the shearing height h. Fig.11 (5) Fig.12 ).
[0094] The conveying device 4 starts conveying the web 1 in the direction X1 by the conveying rollers 40 after the cutter pair 5 starts moving to the first position P1. Specifically, the conveying device 4 of the embodiment starts conveying the web 1 after the cutter pair 5 starts moving downstream and before the shearing height h of the upper knife 50 is exceeded.
[0095] At the time when the sheet 1 is started to be transported, Fig.11 As shown in (5) and (6), the upper blade 50 blocks the conveying path of the web 1. In the above embodiment, the conveying speed and timing of the web 1 are controlled so that when the upper blade 50 rises to Fig. 14B At the time when the conveying path of the web 1 is completely opened and the front end of the web 1 does not move downstream beyond the upstream surface of the upper knife 50. Thus, before the front end of the web 1 reaches the upstream surface of the upper knife 50, a space for the web 1 to pass through can be ensured between the upper knife 50 and the lower knife 51. In this way, even if the conveying path is blocked by the upper knife 50 at the time when the web 1 starts to be conveyed, the conveying device 4 can make the web 1 pass through the space between the upper knife 50 and the lower knife 51 without colliding with the upper knife 50. Fig. 14B , Fig. 14C The height of the upper blade 50 is set as the "lower limit height that can be transported".
[0096] Thereafter, the conveying device 4 conveys the web 1 by a predetermined pitch and stops again temporarily after completion. Thereafter, the above steps are repeated as one cycle of cross-cutting.
[0097] Fig.13 A timing chart showing a comparative example. Fig.12In the embodiment, in the second reciprocating motion of the upper knife 50, the tool pair 5 starts to move from the second position P2 to the downstream during the time when the upper knife 50 reaches the bottom dead center to the time when the upper knife 50 reaches the top dead center. That is, the timing of the start of the downstream movement of the tool pair 5 is earlier than that of the comparative example in which the tool pair starts to move from the second position after the upper knife reaches the top dead center. Moreover, Fig.12 In the embodiment of the present invention, the upper knife 50 is also reset to the first position P1 before the upper knife 50 reaches the top dead center, but this is of course earlier than the comparative example.
[0098] Fig.12 In the embodiment, the web 1 is conveyed from the time when the tool pair 5 starts moving to the first position P1 to the time when the upper knife 50 reaches the top dead center. The timing of starting the conveyance of the web 1 is earlier than that of the comparative example in which the web 1 is conveyed after the upper knife reaches the top dead center and the tool pair reaches the first position.
[0099] Thus, in the embodiment, one cycle of cross cutting is shortened by S( Fig.12 ), and shorten the intermittent conveying cycle. This helps to speed up bag making.
[0100] Instead of the above, the horizontal moving device 7 may also move the knife pair 5 from the second position P2 to the first position P1 immediately when the upper knife 50 reaches the bottom dead center, and then return to the first position P1 and end. Then, the conveying device 4 may start conveying the web 1.
[0101] Instead of the above, the conveying device 4 may start conveying the web 1 after the upper blade 50 exceeds the shearing height h and before reaching the top dead center. Fig. 14B , Fig. 14C After reaching the lower limit height that can be conveyed, the conveying device 4 starts conveying the sheet 1. According to the example, since the space through which the sheet 1 can pass has been ensured between the upper knife 50 and the lower knife 51 at the start time of conveying the sheet 1, the timing or speed of conveying the sheet 1 is simple to control.
[0102] Furthermore, the embodiment has the following advantages in removing the residue 18 , particularly the micro-residue 180 , due to the above-described structure.
[0103] Reference Fig.15A , Fig. 15B , the microscopic behavior of the micro residue 180 of the embodiment is described. The heat sealing device 20 ( Figure 1 ) utilizes the melting of the sealant layer to heat seal the two sheets 1 or the folded sheets 1 to each other. Then, the cross-cutting device 3 is formed at the transverse sealing portion 12 ( Figure 2) is cross-cut at a position within the sheet 1. Fig.15A As shown, in the tablet 1 and the micro residue 180 , the sealant layer 101 is sandwiched between the base material layers 100 .
[0104] When the upper blade 50 descends and cooperates with the lower blade 51 to shear the web 1, heat is generated. Due to the shearing heat, the sealant layer 101 inside the web 1 and the micro residue 180 becomes semi-molten on the shearing surface. The micro residue 180 adheres to the upper blade 50 through the sealant layer 101 in the semi-molten state. In this state, the upper blade 50 descends to the bottom dead point.
[0105] When the upper knife 50 turns to rise and its front end reaches the height of the material sheet 1, the horizontal moving device 7 causes the upper knife 50 and the lower knife 51 to start moving downstream ( Fig. 15B ). Thus, since the micro residue 180 is away from the front end of the tablet 1 along the direction X1, the micro residue 180 and the tablet 1 are not welded via the sealant.
[0106] A suction device (not shown) is disposed below the lower blade 51. Fig. 15C When the upper knife 50 is turned to rise, the suction device generates a downward airflow through suction, and the micro-residues 180 are blown away by the airflow, making them away from the upper knife 50.
[0107] FIG. 16A to FIG. 16D In the comparative example where the upper blade 50 and the lower blade 51 are moved downstream after the upper blade 50 reaches the top dead center, when the upper blade 50 rises, the micro residue 180 may pass through the leaked semi-molten sealant 102 ( Fig. 16C ) and attached to the sheet 1. As a result, Fig.16D As shown, micro-residues 180 may be connected to bag 10 via sealant 102 in the form of a strip.
[0108] As is clear from the comparison between the embodiment and the comparative example, the embodiment can prevent the micro residues 180 from adhering to the web 1, and thus can prevent the micro residues 180 from adhering to the bag 10. Therefore, the embodiment can prevent the micro residues 180 from being mixed as foreign matter in the subsequent filling process.
[0109] In addition, although the description is made in conjunction with the micro-residue 180, it is easily understood by those skilled in the art that the cross-cutting device and method of the present application can also be applied to a bag-making machine and a bag-making method that are not accompanied by notch processing and thus produce a long and thin residue each time the cross-cutting is performed without producing the micro-residue 180.
[0110] Surface treatment for reducing friction, such as Teflon (registered trademark) processing, may be applied to the surface of the upper blade 50 , thereby keeping the micro-residues 180 away from the upper blade 50 more reliably.
[0111] If the web 1 is conveyed too early, the front end of the web 1 hits the upstream surface of the upper blade 50. If the web 1 is conveyed after the upper blade 50 exceeds the lower limit height that can be conveyed, the micro residues 180 can be prevented from adhering to the web 1 more reliably.
[0112] The cross-cutting device 3 is of course not limited to the bag-making of the above-mentioned example, and can be applied to any type of bag-making. For example, in addition to the material sheet 1 (continuous main body), auxiliary components such as gussets (side gussets, bottom gussets, etc.) or zippers can also be used. Instead of two-row bag-making as in the embodiment, the cross-cutting device 3 can also be applied to one-row bag-making or three or more rows of bag-making. The cross-cutting device 3 is particularly effective in preventing short residues from being connected to the bag body in bag-making in which two cuts are made at a narrow interval. Furthermore, the cross-cutting device 3 can be used to accelerate the timing of the start of the intermittent conveying cycle of the material sheet 1, thereby increasing the bag-making speed.
[0113] Explanation of symbols
[0114] 1: Blank
[0115] 10: bag
[0116] 13: Hole for cutting corners
[0117] 14: Cutting edge for corner cutting
[0118] 15: Hole for notch
[0119] 16: Corner cutting
[0120] 17: Notch
[0121] 18: Residue
[0122] 180: Micro residue
[0123] 2: Processing equipment
[0124] 20: Heat sealing device
[0125] 21: Punching device
[0126] 210: First punching knife
[0127] 211: Second punching knife
[0128] 3: Cross-cutting device
[0129] 31: Control Department
[0130] 4: Transport device
[0131] 5: Tool alignment
[0132] 50: Upper Knife
[0133] 51: Cut
[0134] 6: Up and down moving device
[0135] 7: Horizontal moving device
[0136] X: Upstream and downstream direction / length direction of the sheet / horizontal direction
[0137] X1: Conveying direction
[0138] Y: Width direction of the sheet / horizontal direction
[0139] P1: First position
[0140] P2: Second position
Claims
1. A cross-cutting device for bag making, which is used to shear the material twice during the temporary stop of intermittent conveying, comprising: Tool pair, including upper and lower knives; A conveying device, used for intermittently conveying the sheet along the length direction of the sheet; An up-and-down moving device, used to reciprocate the upper knife up and down relative to the lower knife in order to shear the sheet; as well as a horizontal movement device for horizontally moving the pair of cutters between a first position for a first shearing operation and a second position for a second shearing operation which is further upstream than the first position, The horizontal moving device is configured to move the knife pair from the second position to the first position from after the upper knife reaches the lowest height to before exceeding the shearing height during the reciprocating movement of the upper knife for the second shearing. The conveying device is configured to start conveying the web after the pair of cutters starts moving from the second position to the first position.
2. The cross-cutting device according to claim 1, wherein: The conveying device is configured as follows: In the reciprocating movement of the upper knife for the second shearing, the web is conveyed before the upper knife exceeds the shearing height, and after the upper knife exceeds the shearing height, the web is passed through the space between the upper knife and the lower knife.
3. The cross-cutting device according to claim 1, wherein: The conveying device is configured as follows: During the reciprocating movement of the upper knife for the second shearing, the web starts to be conveyed after the upper knife exceeds the shearing height and before it reaches the maximum height.
4. A bag making machine which manufactures bags sequentially from at least one sheet of material and comprises the cross-cutting device as claimed in claim 1.
5. The bag making machine according to claim 4, comprising a punching device, which is arranged upstream of the cross-cutting device and is used to punch the sheet at each intermittent conveyance. The punching device comprises: A first punching knife, used for forming a hole or a cutout for a corner cutting portion on the sheet; as well as The second punching blade is used to form a hole for a notch on the material sheet at a position away from the hole or the notch for the corner cutting portion in the width direction of the material sheet, The cross-cutting device is configured to use the pair of cutters to shear the material sheet in the width direction of the material sheet in a manner that crosses the hole or notch for the corner cutting portion and the hole for the notch, thereby forming the bag having the notch and the corner cutting portion.
6. A cross-cutting method for shearing a web using a pair of knives including an upper knife and a lower knife to form a bag, the cross-cutting method comprising: (a) temporarily stopping the conveyance of the web; (b) during step (a), the upper knife is reciprocated up and down relative to the lower knife, thereby shearing the web along the width direction of the web at a first position; (c) during step (a), subsequent to step (b), moving the pair of tools from the first position to a second position further upstream than the first position; (d) following step (c), the upper knife is moved reciprocally up and down relative to the lower knife again to shear the web along the width direction of the web at the second position; (e) in step (d), the knife pair is moved from the second position to the first position after the upper knife reaches the lowest height and before the upper knife exceeds the shearing height; and (f) After the step (e), the web is conveyed along the length direction of the web.
7. The cross-cutting method according to claim 6, wherein: In the step (f), the material sheet starts to be conveyed before the upper knife exceeds the shearing height in the step (d), and the material sheet is passed through the space between the upper knife and the lower knife after the upper knife exceeds the shearing height.
8. The cross-cutting method according to claim 6, wherein: In the step (f), the web is conveyed after the upper knife exceeds the shearing height in the step (d) and before reaching the maximum height.
9. The cross-cutting method according to claim 6, wherein: The web includes a sealant layer.