Sheet material seal-cutting device

Abstract

To provide a seal cutting device capable of preventing adhesion of residue to a cut part of a sheet material while maintaining high processing capacity.SOLUTION: The seal cutting device 21 is a device for cutting the sheet material S while sealing it, and is provided with an anvil 26 for supporting the sheet material S, an ultrasonic horn 28 for seal-cutting the sheet material S by traveling on the anvil 26 through the sheet material S, and a control device for controlling the traveling speed of the ultrasonic horn 28. The control device changes the traveling speed of the ultrasonic horn 28 from a first speed to a second speed lower than the first speed at a predetermined position while the ultrasonic horn 28 is traveling on the sheet material S.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a seal cutting device that cuts sheet material while sealing it. [Background technology]

[0002] Known devices for cutting sheet material while sealing include those that form water-permeable filtering sheets such as nonwoven fabrics used for tea bags for black tea, green tea, herbs, etc., and dashi packs for dried sardines, dried bonito flakes, etc., into flat, tetrahedral, or other shaped bags, and then fill the bags with tea leaves or other extraction materials (see Patent Document 1). This device sandwiches overlapping thin sheet material between an ultrasonic horn with a sharp tip and an anvil, and cuts the sheet material while sealing it by moving the tip of the ultrasonic horn along the anvil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6123798 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional equipment, increasing the ultrasonic horn movement speed can result in the sheet material (e.g., polymer) not being sufficiently melted, resulting in fibrous residue adhering to the tip of the ultrasonic horn. If such residue adheres to the cut portion of the sheet material, it can mar the appearance of the product and pose a risk of contamination of beverages, etc. Meanwhile, slowing the ultrasonic horn movement speed can result in reduced productivity.

[0005] An object of the present invention is to provide a seal cut device that can prevent residue from adhering to the cut portion of the sheet material while maintaining high processing capacity. [Means for solving the problem]

[0006] The first invention of the present invention is a sheet material seal-cutting device that seals the overlapping portions of folded sheet material at predetermined intervals along a predetermined direction and cuts the sheet material along the sealed portions, and is equipped with an anvil that supports the folded sheet material, an ultrasonic horn that runs on the anvil through the folded sheet material to seal and cut, and a control device that controls the running speed of the ultrasonic horn, wherein the control device changes the ultrasonic horn from a first speed to a second speed at a predetermined position while it is running on the sheet material, and the second speed is slower than the first speed. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a seal cutting device that can prevent residue from adhering to the cut portion of the sheet material while maintaining high processing capacity. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing the configuration of a filling device using a seal cut device according to one embodiment of the present invention. [Figure 2] 2 is a schematic side view of the seal cutter of the present embodiment as seen from the sheet material conveying direction. FIG. [Figure 3] FIG. 2 is an enlarged plan view showing the configuration of an ultrasonic horn and an anvil. [Figure 4] 10A and 10B are diagrams showing the positions of the tip of the ultrasonic horn relative to the sheet material at the start and end of the seal cutting process, as viewed from a direction perpendicular to the sheet material conveyance direction. [Figure 5] 1 is a graph showing the relationship between the time elapsed from the start of the seal cutting process (horizontal axis) and the moving speed V of the ultrasonic horn (vertical axis). DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the configuration of a filling device using a seal cut device according to one embodiment of the present invention.

[0010] The filling device 10 continuously transports a large number of filling nozzles 12 along an endless track. A hopper 14 for supplying items such as coffee is disposed above the straight portion of the endless track, and a weighing device 16 for weighing the items supplied from the hopper 14 is disposed between the hopper 14 and the filling nozzle 12. The weighing device 16 is configured as a rotary drum, and on its outer periphery, measuring storage sections 16A, each capable of holding a predetermined volume of items, are provided at predetermined intervals along the circumferential direction. The weighing device 16 is continuously rotated in synchronization with the transported filling nozzles 12. At a supply position P, each storage section 16A is sequentially positioned directly above the filling nozzle 12 transported along the straight portion, and the items in the storage sections 16A are fed into the filling nozzle 12 at the same positions.

[0011] Meanwhile, below the straight section, a packaging sheet material S runs continuously along the straight section. The sheet material S is unwound from a roll film (not shown) via a pull-out roller 18, and is sandwiched between a pair of left and right feed rollers 20 just before the straight section and folded in half upward. Also, just before a supply position P for articles onto the sheet material S running along the straight section, a seal cutter 21 is disposed which seals and cuts the folded sheet material S in the longitudinal direction at predetermined intervals.

[0012] As will be described later, the seal cutting device 21 is equipped with an ultrasonic horn 28 and an anvil 26 (see FIG. 2), and clamps the continuously running sheet material S, folded in half, from both sides to seal it vertically, forming side seals at predetermined intervals. As a result, bags B of a predetermined width that are open at the top along the longitudinal direction of the folded sheet material S are formed. The seal cutting device 21 also cuts the side seals at the same time as sealing, separating the bags B. Each cut bag B is held by a holding device (not shown) and transported downstream along the straight section.

[0013] When the stuffing nozzle 12, which is transported on the endless track, reaches a straight section, it is lowered and its lower end (tip) is inserted between the folded sheet material S. Thereafter, the stuffing nozzle 12 is transported with its tip inserted between the sheet material S, and the front and rear sides are side-sealed by the seal cutter 21. In other words, the tip of the stuffing nozzle 12 is inserted into each bag B. When an item is supplied to the stuffing nozzle 12 at supply position P, the item is dispensed from the stuffing nozzle 12 into each bag B of the sheet material S.

[0014] Once the items have been placed into each bag B at supply position P, the filling nozzle 12 is immediately raised and the items are removed from the bag B. A top sealing device 22 that seals the opening at the top of the bag B is located on the transport path of the bags B as they are filled with items and transported along the straight section. Also located downstream of this is a top seal inspection device 24 that determines whether the top seal is good or bad. The top seal inspection device 24 determines the seal condition using, for example, image processing, and bags B that pass through the top seal inspection device 24 are sent to a downstream processing device (not shown), and bags B that are determined to be defective are discharged from the line.

[0015] Fig. 2 is a schematic side view of the seal cutter 21 of this embodiment as seen from the sheet conveying direction, and Fig. 3 is an enlarged plan view showing the configuration of the ultrasonic horn 28 and the anvil 26.

[0016] The anvil 26 of the seal cutter 21 has a vertically elongated shape with, for example, a regular octagonal cross section, and is positioned vertically with one side of the octagon facing the folded sheet material S traveling horizontally along the straight portion of the conveyor track. The anvil 26 is held via a slider 30A on a base plate 30 supported by a rail 32A arranged on a base 32. The base plate 30 can be moved back and forth horizontally along the rail 32A, perpendicular to the traveling direction of the sheet material S, by a linear actuator such as an air cylinder 34. The height of the anvil 26 is set to a dimension that extends at least from the bottom end to the top end of the folded sheet material S.

[0017] On the other hand, ultrasonic horn 28 of seal cut device 21 extends horizontally from vibrator 28A toward doubled sheet material S traveling horizontally along the straight portion of the conveying track. Vibrator 28A is attached to support plate 38, which is supported by frame 40 so that it can move up and down freely while maintaining its posture. Ultrasonic horn 28 faces anvil 26 with the traveling sheet material S sandwiched between them, and frame 40 is supported by slider 40B on rail 44A provided on base 44, and can be moved forward and backward along rail 44A in the horizontal direction perpendicular to the traveling direction of sheet material S by a linear actuator such as air cylinder 46.

[0018] A motor 48 is provided on the frame 40, and the rotation shaft of the motor 48 is connected to the support plate 38 via a link mechanism 50. When the motor 48 rotates, the support plate 38, i.e., the ultrasonic horn 28, is raised and lowered in the sealing direction relative to the frame 40 via the link mechanism 50.

[0019] 3, in front of and behind the ultrasonic horn 28 (in the sheet material conveying direction), presser members 52 are arranged to pinch the sheet material S traveling between the ultrasonic horn 28 and the anvil 26 and prevent the sheet material S from shifting. The bases 32 and 44 can reciprocate in the conveying direction in accordance with the movement of the sheet material S by a mechanism not shown.

[0020] Next, the seal cutting process of the sheet material S by the seal cutting device 21 of this embodiment will be described with reference to Figures 4 and 5. Figure 4 is a side view showing the position of the tip of the ultrasonic horn 28 relative to the sheet S from a direction perpendicular to the sheet conveying direction, with Figure 4(a) showing the state at the start of the seal cutting process and Figure 4(b) showing the state at the end of the seal cutting process. Figure 5 is a graph showing the relationship between the elapsed time t (horizontal axis) from the start of the seal cutting process and the moving speed (traveling speed) V (vertical axis) of the ultrasonic horn 28, with Figures 5(a) and 5(b) illustrating embodiments employing different moving speeds.

[0021] At the start of the seal cutting process, the anvil 26 and the ultrasonic horn 28 are pushed toward each other by the air cylinders 34, 46, respectively, toward the sheet material S, and they clamp the sheet material S. At this time, the support plate 38 is lowered, and the tip of the ultrasonic horn 28 is pressed against the anvil 26 at a position slightly lower than the lower end position of the sheet material S, as shown in FIG. 4(a). Thereafter, the support plate 38 is raised by the motor 48 and link mechanism 50, and the ultrasonic horn 28 is raised together with the support plate 38. Here, the motor 48 is controlled by a control device (not shown) so that the tip of the ultrasonic horn 28 moves at a speed V according to the graphs of FIGS. 5(a) and 5(b), for example.

[0022] 5(a) and 5(b), the ultrasonic horn 28 is accelerated at a substantially constant acceleration from the start of the seal cutting process. After that, when the ultrasonic horn 28 passes the sealing start position (position in FIG. 4(a)) where sealing of the sheet material S begins, the speed V of the ultrasonic horn 28 immediately reaches a predetermined first speed V1 (e.g., approximately 60 m / min). The ultrasonic horn 28 then moves (rises) at the first speed V1 across a section A1 below the sheet material S, and then moves (rises) at a second speed V2 slower than the first speed V1 across an upper section A2 up to the sealing end position (position in FIG. 4(b)) where sealing is completed. After passing the sealing end position, the ultrasonic horn 28 decelerates at a substantially constant acceleration and stops.

[0023] For example, the length of section A1 is longer than the length of section A2, and section A2 is, for example, 50% or less of the height of the sheet material S. In the example of FIG. 5(a), the second speed V2 has a section in section A2 where the sheet material moves at a substantially constant speed (for example, about 30 m / min), and before and after that section, the sheet material S is decelerated, for example, at a substantially constant acceleration. Also, in the example of FIG. 5(b), the second speed V2 decelerates continuously and smoothly in section A2. Note that it is preferable that the speed V at the sealing start position (start point of section A1) be faster than the speed V at the sealing end position (end point of section A2).

[0024] During the seal cutting process, the seal cutting device 21 is moved in the sheet material conveying direction following the sheet material S by a moving mechanism (not shown), and is returned to its original position after one side seal is completed.

[0025] As described above, according to the seal cutting device of this embodiment, the movement speed (running speed) of the ultrasonic horn is changed from a first speed to a second speed, which is slower than the first speed, at a predetermined position while traveling on the sheet material, thereby maintaining high processing capacity while ensuring sufficient melting of the sheet material by lowering the movement speed (running speed) of the ultrasonic horn at the end of the seal cutting process, and preventing residue from adhering to the sheet material cutting section.

[0026] In this embodiment, two examples of controlling the moving speed (traveling speed) V of the ultrasonic horn are shown in Figure 5, but the method of controlling the moving speed (traveling speed) is not limited to this. It is sufficient to set the speed high enough to obtain sufficient processing capacity in the first half section A1 of the seal cutting process, and slow enough in the second half section A2 so that residue does not occur in the sheet material cutting section.

[0027] In this embodiment, a filling device that fills bags has been described as an example, but the sealing device of this embodiment is not limited to a filling device as long as it is a device that seals sheet material. Also, in this embodiment, the sealing direction is vertical, but the sealing direction is not limited to this. [Explanation of symbols]

[0028] 10 Filling equipment 21 Seal cutting device 26 Anvil 28 Ultrasonic Horn 30A, 40B slider 32A, 44A rail 34, 46 Air cylinder 48 Motor 50 Link mechanism S sheet material

Claims

[Claim 1] A seal cutter for sheet material seals overlapping portions of folded sheet material at predetermined intervals along a predetermined direction and cuts the sheet material along the sealed portions, an anvil supporting the folded sheet material; an ultrasonic horn that travels over the anvil through the folded sheet material to perform the sealing and cutting; a control device for controlling the traveling speed of the ultrasonic horn, The control device changes the speed of the ultrasonic horn from a first speed to a second speed at a predetermined position while the ultrasonic horn is traveling on the sheet material, and the second speed is slower than the first speed. A seal cutting device for sheet material characterized by:

Images