Heat sealing device

Abstract

A heat-sealing device seals a film for packaging an article by heat-sealing, the film being configured to be sandwiched around the article with a portion overlapping around the article, the heat-sealing device having: a sealing head that heat-seals a sealed portion of the film; a first cooling head that cools the sealed portion after heat-sealing by the sealing head; and a second cooling head that cools at least a portion of an article-side region of the film on the article side than the sealed portion.

Description

Technical Field

[0001] The invention relates to a heat sealing device. Background Art

[0002] Films capable of being heat-welded, such as plastic films, are known as films used for packaging articles. Heat-sealing devices are also known for sealing films by heat-welding. Heat-sealing devices heat-weld films that are positioned to sandwich an article and partially overlap around the article. The heat-sealing device includes a sealing head that heat-welds the sealing portion of the film.

[0003] After a film is sealed by a sealing head, tension is applied to the film, for example, to transport a packaged item. If the film is heated during this tension, the film may stretch. Natural cooling of the sealed portion takes time, so to increase heat sealing throughput, heat sealing devices are equipped with cooling heads to cool the sealed portion after heat fusion by the sealing head (see Japanese Patent Application Publication Nos. 2009-242000 and 2004-237675).

[0004] Meanwhile, Japanese Utility Model Application Laid-Open No. 58-21503 discloses a heat-sealing device for continuously packaging multiple items. Specifically, the heat-sealing device described in Japanese Utility Model Application Laid-Open No. 58-21503 uses a long film extending along the direction in which multiple items are arranged. A sealing rod (equivalent to a sealing head) seals the film covering the multiple items into a strip-like shape between the items. After sealing, a cutter cuts the center of the sealed portion.

[0005] The heat sealing device described in Japanese Utility Model Application Laid-Open No. 58-21503 is equipped with a cooling rod (equivalent to a cooling head) that cools the vicinity of the seal portion sealed by the sealing rod during heat-sealing of films. The cooling rod described in Japanese Utility Model Application Laid-Open No. 58-21503 cools the vicinity of the seal portion, thereby preventing pinholes from forming in the seal portion softened by the heating of the sealing rod. Summary of the Invention

[0006] Technical issues to be solved by the invention

[0007] While the heat sealing devices disclosed in Japanese Patent Application Laid-Open Nos. 2009-242000 and 2004-237675 can cool the sealed portion using a cooling head, there is a problem with preventing heat damage to the article caused by the heat from the sealing head during heat fusion of the sealed portion. This is particularly problematic when sealing thin films of heat-sensitive articles, such as articles whose packaging is susceptible to deterioration or deformation due to heat.

[0008] In the heat sealing device of Japanese Patent Application Publication No. H58-21503, a cooling rod (cooling head) is also used to cool the vicinity of the sealing portion, without considering heat damage to the article.

[0009] The present application was accomplished in view of the above-described circumstances, and aims to provide a heat sealing device capable of improving the throughput of heat sealing while suppressing heat damage to an article packaged by a film.

[0010] Means for solving technical problems

[0011] The heat sealing device of the present application seals a film for packaging an article and configured to sandwich the article and overlap a portion around the article by heat welding, and has:

[0012] a sealing head that heat welds a sealing portion of the film to be sealed;

[0013] a first cooling head that cools the sealing portion after heat welding by the sealing head; and

[0014] a second cooling head that cools at least a portion of an article side region of the film on the article side than the sealing portion.

[0015] In the heat sealing device of the present application, it is preferable to have: a moving mechanism that relatively moves the sealing head, the first cooling head, and the second cooling head with respect to the film; and a control section that controls each of the sealing head, the first cooling head, the second cooling head, and the moving mechanism.

[0016] In the heat sealing device of the present application, the control section preferably starts heat welding of the sealing portion by bringing the sealing head into contact with the sealing portion by the moving mechanism after starting cooling of the article side region by bringing the second cooling head into contact with the article side region by the moving mechanism.

[0017] In the heat sealing device of the present application, the control section preferably retreats the sealing head from the sealing portion by the moving mechanism after heat welding by the sealing head, and brings the first cooling head into contact with the sealing portion by the moving mechanism.

[0018] In the heat sealing device of the present application, the control section preferably continues cooling of the article side region by the second cooling head during a period from the start of heat welding of the sealing portion by the sealing head to the end of cooling of the sealing portion by the first cooling head.

[0019] In the heat sealing device of the present application, the control section preferably controls the temperature of at least one of the first cooling head and the second cooling head to a predetermined temperature.

[0020] In the heat sealing device of the present application, the predetermined temperature is preferably 20°C or lower.

[0021] In the heat sealing device of the present invention, the control unit preferably controls a pressing pressure applied to the contact region when the second cooling head is brought into contact with the article-side region.

[0022] In the heat sealing device of the present invention, when cooling the article side area, the sealing head side end position of the pressing surface of the second cooling head pressing the article side area of ​​the film is preferably closer to the sealing head side than the sealing head side end position of the article.

[0023] In the heat sealing device of the present invention, when cooling the article side region, the pressing surface of the second cooling head that presses the film on the article side region is preferably arranged to face at least the outer peripheral edge of the article.

[0024] In the heat sealing device of the present invention, when cooling the article side region, the pressing surface of the second cooling head that presses the film on the article side region is preferably arranged to face the entire surface of the article.

[0025] In the heat sealing device of the present invention, the sealing head side of the pressing surface may protrude further than the article side, with the position facing the outer peripheral edge of the article as a reference.

[0026] In the heat sealing device of the present invention, when the width of the sealing head is LH and the distance between the sealing head and the second cooling head is D, the relationship between D and LH is preferably

[0027] LH / 1000<D<10LH.

[0028] In the heat sealing device of the present invention, when the width of the sealing head is LH and the width of the first cooling head is LC, the relationship between LH and LC is preferably

[0029] LH / 2<LC.

[0030] In the heat sealing device of the present invention, it is preferred that the sealing portion be provided so as to surround the entire circumference of the article, and the sealing head be formed in a frame shape corresponding to the shape of the sealing portion.

[0031] Effects of the Invention

[0032] According to the heat sealing device of the present invention, it is possible to improve the heat sealing throughput while suppressing heat damage to articles packaged with a film. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a perspective view showing the schematic structure of a heat sealing device.

[0034] Figure 2 It is a diagram for explaining a sealing portion.

[0035] Figure 3 This is a perspective view showing a state where a sealing head and a first cooling head are moved in a heat sealing device.

[0036] Figure 4 It is a schematic diagram of the main view of the heat sealing device.

[0037] Figure 5 It is a side view schematic diagram of the heat sealing device.

[0038] Figure 6 It is a diagram showing the positional relationship among the sealing head, the second cooling head, and the article.

[0039] Figure 7 This is a diagram for explaining the processing steps in the heat sealing device (part 1).

[0040] Figure 8 This is a diagram (part 2) for explaining the processing steps in the heat sealing device.

[0041] Figure 9 This is a timing chart of the rise and fall of the sealing head, the first cooling head, and the second cooling head.

[0042] Figure 10 It is a diagram showing the positional relationship between the end of the article, the sealing head, and the end of the second cooling head during heat welding.

[0043] Figure 11 This is a diagram showing another example of the positional relationship between the end of the article, the sealing head, and the end of the second cooling head during heat welding.

[0044] Figure 12 This is a diagram showing another example of the positional relationship between the end of the article, the sealing head, and the end of the second cooling head during heat welding.

[0045] Figure 13 This is a diagram showing the positional relationship among the second cooling head, the sealing head, and the article in the first design modification.

[0046] Figure 14 This is a diagram showing the positional relationship among the second cooling head, the sealing head, and the article in the second design modification.

[0047] Figure 15 It is a diagram showing the end shape of the third design variation.

[0048] Figure 16 It is a diagram showing the end shape of a fourth design variation. DETAILED DESCRIPTION

[0049] Hereinafter, technical embodiments of the present invention will be described with reference to the drawings.

[0050] [Heat sealing device]

[0051] Figure 1The heat sealing device 10 is a perspective view showing a schematic structure of an embodiment of the present invention. The heat sealing device 10 is a device for sealing films 2a and 2b by heat welding. The films 2a and 2b are used to package articles 1 (refer to FIG. Figure 2 、 Figure 3 ) and is arranged to sandwich the article 1 and partially overlap around the article 1. The heat sealing device 10 of this embodiment includes a sealing head 12, a first cooling head 14, and a second cooling head 16 within a frame 11. In this embodiment, for ease of description, the horizontal plane is referred to as the XY plane, the long side direction of the frame 11 is referred to as the X direction, the short side direction is referred to as the Y direction, and the direction perpendicular to the XY plane is referred to as the Z direction. In other words, the Z direction is a direction along the vertical direction (up and down direction).

[0052] Furthermore, a tray 5 is provided on the frame 11. An article 1 is placed on the tray 5 in a state of being sandwiched between films 2a and 2b. In this example, film 2a is laid on the tray 5, and the article 1 is placed on film 2a, with film 2b being overlapped from above the article 1.

[0053] Figure 2 2a, article 1 and film 2b are overlapped in a plan view and a cross-sectional view. Figure 2 In the plan view, a portion of film 2b is cut away to represent film 2a. The planar dimensions of films 2a and 2b are larger than the planar dimensions of article 1. Article 1 is placed approximately in the center of films 2a and 2b, and in the peripheral portions of films 2a and 2b surrounding article 1, films 2a and 2b overlap in direct contact. A portion of the portion where films 2a and 2b are in direct contact becomes a sealing portion 6 where films 2a and 2b are sealed. In this example, the sealing portion 6 of films 2a and 2b is a strip-shaped area indicated by a single-dotted dashed line in the figure, which is provided so as to surround the entire circumference of article 1. In addition, in this specification, the area closer to article 1 than the sealing portion 6 is referred to as the article side area 8. Hereinafter, when it is necessary to distinguish between films 2a and 2b, a subdivision code a or b is added to distinguish them. When it is not necessary to distinguish them, they are referred to as film 2 without a subdivision code.

[0054] The heat sealing device 10 further includes: a moving mechanism 18 that moves the sealing head 12, the first cooling head 14, and the second cooling head 16 relative to the film 2; and a control unit 90 that controls the sealing head 12, the first cooling head 14, the second cooling head 16, and the moving mechanism 18 (see Figure 4 ).

[0055] Figure 3 The heat sealing device 10 is used to make the sealing head 12, the first cooling head 14 and the second cooling head 16 Figure 1Specifically, in Figure 3 In the embodiment, the sealing head 12 and the first cooling head 14 are Figure 1 The position moves in the X direction, and the second cooling head 16 moves from Figure 1 The position moves upward in the Z direction. Figure 4 A schematic front view of the heat sealing device 10 and a schematic diagram of the functional structure of the control unit 90 are shown. Figure 5 1 is a schematic side view of the heat sealing device 10.

[0056] The sealing head 12 heat-seals the sealing portion 6 of the film 2. In this example, the sealing head 12 has a rectangular frame shape, and a sealing surface 20 that contacts the film 2 is formed on the surface facing the film 2. The sealing surface 20 has the same shape as the sealing portion 6 surrounding the outer periphery of the article 1 and faces the sealing portion 6. A heater (not shown) and a temperature sensor 21 (see FIG. 2 ) are built into the sealing head 12. Figure 4 ). By running the heater, the sealing surface 20 of the sealing head 12 is heated. The temperature sensor 21 detects the temperature of the sealing surface 20. The sealing head 12 is preferably made of a metal such as stainless steel or a material with high thermal conductivity such as ceramic. Figure 2 As shown, in this example, the sealing portion 6 is arranged in a manner that surrounds the entire circumference of the article 1, and the shape of the sealing head 12 is a frame corresponding to the shape of the sealing portion 6. In this example, the article 1 is rectangular, so the sealing head 12 is a frame with a rectangular opening 22 corresponding to the shape of the article 1. In this way, the sealing portion 6 surrounding the entire circumference of the article 1 can be sealed at one time. The frame shape is a rectangular frame in this example, but it can also be a circular frame, a polygonal frame other than a rectangle, etc. depending on the article. In the sealing head 12, the sealing surface 20 heated by the heater is pressed against the sealing portion 6, and the sealing portion 6 is heat-sealed. In addition, in this example, the shape of the sealing surface 20 of the sealing head 12 is a similar shape along the outer shape of the article 1, but if the shape of the sealing surface 20 is larger than the outer shape of the article 1, it may not be similar to the outer shape of the article 1. In addition, the sealing portion 6 is not necessarily limited to the entire outer periphery area, but can also be a part of the outer periphery. What shape the sealing portion 6 is set to can be appropriately determined according to the design.

[0057] After the sealing head 12 is used for heat welding, the first cooling head 14 cools the sealing portion 6. In this example, the first cooling head 14 is the same as the sealing head 12, and has a rectangular frame shape. A pressing surface 40 that contacts the film 2 is formed on the surface opposite to the film 2. The pressing surface 40 is substantially the same frame shape as the sealing surface 20 of the sealing head 12, and is opposite to the sealing portion 6. The first cooling head 14 has a cooling element (not shown) and a temperature sensor 41 (see FIG. Figure 4). By operating the cooling element, the pressing surface 40 is cooled. The first cooling head 14 is preferably made of a material with high thermal conductivity, such as a metal such as aluminum. In this example, the shape of the first cooling head 14 is the same as that of the sealing head 12, and is a frame with a rectangular opening 42. After heat welding using the sealing head 12, the first cooling head 14 is pressed against the sealing portion 6 by the pressing surface 40 cooled by the cooling element, thereby cooling the sealing portion 6.

[0058] The shape of the pressing surface 40 of the first cooling head 14 is not necessarily the same as that of the sealing surface 20 as long as the sealing portion 6 can be cooled, and can be appropriately determined depending on the shape of the sealing portion 6 or the shape of the sealing head 12.

[0059] Furthermore, let the width of the sealing head 12 be LH (refer to Figure 3 and Figure 6 ), the width of the first cooling head 14 is LC (reference Figure 3 ), the relationship between LH and LC is preferably LH / 2<LC. Here, LH corresponds to the width of the sealing portion 6. More specifically, in this example, the sealing portion 6 is in the shape of a rectangular frame, and the width of the sealing portion 6 refers to the width in the direction perpendicular to the direction in which one side of the rectangular frame extends. Moreover, in this example, corresponding to the shape of the sealing portion 6, the sealing head 12 and the first cooling head 14 are both in the shape of a rectangular frame, as shown in FIG. Figure 3 and Figure 6 As shown, LH and LC also refer to the width in a direction perpendicular to the direction in which one side of the rectangular frame extends. If LC is greater than half of LH, more than half of the sealing portion 6 can be cooled, thereby achieving effective cooling. However, it is preferable to be able to press on the entire area of ​​the sealing portion 6. In addition, when the sealing head 12 and the first cooling head 14 are annular frame-shaped, LH and LC are the radial widths of the ring within the annular line.

[0060] The second cooling head 16 cools at least a portion of the article side region 8 of the film 2 that is closer to the article 1 than the sealing portion 6. In this example, the second cooling head 16 has a pressing surface 60 having the same size and shape as the article 1. A cooling element (not shown) and a temperature sensor 61 (see FIG. 1 ) are built into the second cooling head 16. Figure 4). By operating the cooling element, the pressing surface 60 is cooled. In this example, the second cooling head 16 is in the shape of a flat plate, and its planar shape is rectangular. The planar size of the second cooling head 16 is smaller than the planar size of the opening 22 of the sealing head 12. In this embodiment, the second cooling head 16 presses the pressing surface 60 to the article side area 8 of the film 2b. The film 2b is in contact with the peripheral surface (the upper surface in this example) of the article 1. Therefore, by pressing the pressing surface 60 of the second cooling head 16 to the article side area 8 of the film 2, the peripheral surface of the article 1 is pressed by the pressing surface 60 via the film 2b. As a result, the article 1 is cooled. That is, the first cooling head 14 has the function of cooling the sealing portion 6, whereas the second cooling head 16 has the function of cooling the article 1 via the film 2b.

[0061] The cooling elements included in the first cooling head 14 and the second cooling head 16 are, for example, Peltier elements. However, other cooling mechanisms such as air cooling and water cooling may be included as the cooling elements.

[0062] Figure 6 6B-6B is a diagram showing the positional relationship between the sealing head 12 and the second cooling head 16 in this embodiment. The upper figure is a plan view and the lower figure is a 6B-6B cross-sectional view. Figure 6 As shown, the second cooling head 16 is pressed onto the article 1 via the film 2b, and the sealing head 12 is pressed onto the sealing portion 6 surrounding the article 1. A gap D is provided between the sealing head 12 and the second cooling head 16 to prevent the sealing head 12 and the second cooling head 16 from interfering with each other when they are raised or lowered. Specifically, the gap D is the distance between the inner peripheral surface of the frame-shaped sealing head 12 and the outer peripheral surface of the second cooling head 16. If the gap D is several μm or more, for example, 2 μm or more, the sealing head 12 and the second cooling head 16 can be raised or lowered without interfering with each other. Assuming that the width of the sealing portion 6, that is, the width of the sealing head 12, is LH, the gap D preferably satisfies LH / 1000<D<10LH.

[0063] The width LH of the sealing head 12 can be appropriately set according to the product and the like, and is, for example, 1 mm to 20 mm.

[0064] In this embodiment, if Figure 1 、 Figure 3 and Figure 4 As shown, the moving mechanism 18 includes a sealing head Z-direction moving portion 28, a first cooling head Z-direction moving portion 48, a second cooling head Z-direction moving portion 68, and an X-direction moving portion 70 for moving the sealing head 12 and the first cooling head 14 in the X-direction. The sealing head Z-direction moving portion 28 moves the sealing head 12 in the Z-direction. The first cooling head Z-direction moving portion 48 moves the first cooling head 14 in the Z-direction. The second cooling head Z-direction moving portion 68 moves the second cooling head 16 in the Z-direction.

[0065] In this example, the sealing head Z-direction moving portion 28 is composed of two cylinders 26a and 26b and two shafts 24a and 24b extending in the Z direction. A portion of the upper end of shaft 24a is housed within cylinder 26a. As the amount of cylinder 26a accommodated toward the upper end of shaft 24a changes, the portion of shaft 24a protruding downward from cylinder 26a expands and contracts in the Z direction. An actuator for expanding and contracting shaft 24a is built into cylinder 26a. The actuator can be composed of, for example, a hydraulic pump, a motor, and a solenoid. Thus, the combination of cylinder 26a and shaft 24a extending in the Z direction forms a telescopic mechanism. The combination of cylinder 26b and shaft 24b also forms a telescopic mechanism similar to the combination of cylinder 26a and shaft 24a. These two sets of telescopic mechanisms constitute the sealing head Z-direction moving portion 28.

[0066] The lower ends of the shafts 24a and 24b constituting each telescopic mechanism are mounted on each of the two opposite sides of the frame-shaped sealing head 12. The shafts 24a and 24b are respectively extended and retracted relative to the cylinders 26a and 26b, thereby changing the position of the sealing head 12 in the Z direction. In this way, the sealing head Z-direction moving portion 28 causes the sealing head 12 to rise and fall relative to the film 2. In addition, in order to prevent the sealing surface 20 from tilting when the sealing head 12 is raised and lowered, in the sealing head Z-direction moving portion 28, two sets of telescopic mechanisms are synchronously driven, thereby controlling the telescopic amounts to be consistent. Figure 1 , the shafts 24a and 24b are shown to be extended relative to the cylinders 26a and 26b, respectively, and to press the sealing portion 6 via the sealing surface 20 of the sealing head 12. Figure 3 , the shafts 24a and 24b are shown in a state where they are retracted relative to the cylinders 26a and 26b, respectively.

[0067] The first cooling head Z-direction moving portion 48 in this example also has a structure roughly the same as the sealing head Z-direction moving portion 28. Specifically, the first cooling head Z-direction moving portion 48 is composed of two cylinders 46a and 46b and two shafts 44a and 44b extending in the Z direction. The two cylinders 46a and 46b and the two shafts 44a and 44b extending in the Z direction form two sets of telescopic mechanisms. Cylinders 46a and 46b have actuators similar to those of cylinders 26a and 26b. The lower ends of the shafts 44a and 44b that constitute each telescopic mechanism are attached to one end of each of the two opposing sides of the frame-shaped first cooling head 14. The shafts 44a and 44b extend and retract relative to the cylinders 46a and 46b, thereby changing the Z-direction position of the first cooling head 14. In this way, the first cooling head Z-direction moving portion 48 raises and lowers the first cooling head 14 relative to the film 2.

[0068] The second cooling head Z-direction moving portion 68 is composed of a cylinder 66 and a shaft 64 extending in the Z direction. The cylinder 66 and the shaft 64 constitute a telescopic mechanism. This telescopic mechanism is the same as the telescopic mechanism described above in the sealing head Z-direction moving portion 28 and the first cooling head Z-direction moving portion 48. The lower end of the shaft 64 is mounted on the central portion of the second cooling head 16. The shaft 64 is extended and retracted relative to the cylinder 66, thereby changing the position of the second cooling head 16 in the Z direction. In this way, the second cooling head Z-direction moving portion 68 causes the second cooling head 16 to rise and fall relative to the film 2. In addition, in this embodiment, the second cooling head Z-direction moving portion 68 is further provided with a load sensor 67 for detecting pressing pressure.

[0069] The X-direction moving unit 70 moves the sealing head 12 and the first cooling head 14 in the X-direction, which is the longitudinal direction of the frame 11. In this example, the X-direction moving unit 70 moves the sealing head 12 and the first cooling head 14 integrally in the X-direction, thereby selectively switching between two positions: a position where the sealing head 12 faces the sealing portion 6 of the film 2, and a position where the first cooling head 14 faces the sealing portion 6 of the film 2.

[0070] As an example, the X-direction moving portion 70 includes two parallel ball screws 72a and 72b, first moving blocks 74a and 74b threadedly engaged with the ball screws 72a and 72b, second moving blocks 76a and 76b, guide rails (not shown), and stepping motors 75a and 75b.

[0071] The cylinders 26a and 26b of the sealing head Z-direction moving portion 28 are fixed to the first moving blocks 74a and 74b, respectively. Furthermore, the cylinders 46a and 46b of the first cooling head Z-direction moving portion 48 are fixed to the second moving blocks 76a and 76b, respectively. The first moving blocks 74a and 74b and the second moving blocks 76a and 76b are mounted on guide rails (not shown) provided on the ceiling of the frame 11, for example, so as to be movable in the X-direction. The ball screws 72a and 72b are each rotatably supported by a pair of shaft supports 73a and 73b mounted on opposing walls perpendicular to the X-direction of the frame 11. One end of each ball screw 72a and 72b is connected to the drive shaft of the forward and reverse rotating stepper motors 75a and 75b. Therefore, when the ball screws 72a and 72b are rotated by the stepping motors 75a and 75b, the first moving blocks 74a and 74b and the second moving blocks 76a and 76b advance and retreat in the direction X. As a result, the sealing head 12 and the first cooling head 14 move linearly in the direction X.

[0072] As described above, the X-direction moving unit 70 moves the sealing head 12 and the first cooling head 14 integrally in the X-direction, thereby selectively positioning the sealing head 12 and the first cooling head 14 opposite to the film 2. The position where the sealing head 12 faces the sealing portion 6 of the film 2 is Figure 1 The position shown in Figure 4 The sealing head 12 and the first cooling head 14 move integrally along the X direction, so the interval in the X direction is constant. Figure 1 As shown, when the sealing head 12 is at the processing position X1, the first cooling head 14 is at the second retreat position X2, which is retreated from the processing position X1. Furthermore, when the first cooling head 14 moves from the second retreat position X2 to the processing position X1, which faces the sealed portion 6 of the film 2, the sealing head 12 moves across the processing position X1 to the first retreat position X0, which is opposite the second retreat position X2. In this way, the sealing head 12 can move between the processing position X1, where it seals the films 2a and 2b sandwiching the article 1, and the first retreat position X0. Furthermore, the first cooling head 14 can move between the second retreat position X2 and the processing position X1.

[0073] The X-direction moving portion 70 is not limited to the structure using the above-mentioned ball screw, and other well-known linear moving mechanisms such as a rack and pinion can be applied.

[0074] Meanwhile, the cylinder 66 of the second cooling head Z-direction moving portion 68 is fixed to a fixed block 84, which is in turn fixed to a support shaft 82 arranged parallel to the ball screws 72a and 72b. That is, unlike the first cooling head 14, the second cooling head 16 cannot move in a horizontal direction including the X-direction and can only move in the Z-direction. Thus, the heat sealing device 10 lacks a mechanism for horizontally moving the second cooling head 16, but may include a mechanism for horizontally moving the second cooling head 16.

[0075] like Figure 4 As shown, in this embodiment, the control unit 90 is included in the control device 100, and the control device 100 has a memory 92. The control unit 90 comprehensively controls the various parts of the heat sealing device 10. The control unit 90 is composed of a processor. An example of a processor is a CPU (Central Processing Unit) that performs various controls by executing programs. The CPU functions as a control unit 90 having a motion control unit 94 and a temperature control unit 96 by executing the program. The memory 92 is an example of a memory connected to or built into the CPU as a processor. For example, a control program is stored in the memory 92. The control unit 90 is implemented by the CPU executing the control program. The control unit 90 has a motion control unit 94 and a temperature control unit 96. These are implemented by the CPU executing the control program.

[0076] In addition to the control program, the memory 92 also stores setting information preset by the control unit 90 for various control operations. This setting information includes information required for controlling the movement of the sealing head 12 and the first cooling head 14 in the X direction, and for controlling the movement of the sealing head 12, the first cooling head 14, and the second cooling head 16 in the Z direction. Furthermore, in this embodiment, the setting information also includes information required for controlling the temperature of each of the sealing head 12, the first cooling head 14, and the second cooling head 16.

[0077] The movement control unit 94 includes an X-direction movement control unit 94a, a sealing head Z-direction movement control unit 94b, a first cooling head Z-direction movement control unit 94c, and a second cooling head Z-direction movement control unit 94d. The movement control unit 94 controls the X-direction movement unit 70, the Z-direction movement unit 28 of the sealing head 12, the Z-direction movement unit 48 of the first cooling head 14, and the Z-direction movement unit 68 of the second cooling head 16 through the movement control units 94a to 94d.

[0078] The X-direction movement control unit 94a drives the stepping motors 75a and 75b of the X-direction movement unit 70. During the sealing process, the X-direction movement control unit 94a controls the X-direction movement of the sealing head 12 and the first cooling head 14 so that the sealing head 12 is located at the processing position X1 and the first cooling head 14 is located at the second retreat position X2. Furthermore, after the sealing process, in order to cool the sealed portion in the cooling process, the X-direction movement control unit 94a controls the X-direction movement of the sealing head 12 and the first cooling head 14 so that the sealing head 12 is retreated from the processing position X1 to the first retreat position X0 and the first cooling head 14 is positioned from the second retreat position X2 to the processing position X1.

[0079] The sealing head Z-direction movement control unit 94b drives the cylinders 26a and 26b to extend and retract the shafts 24a and 24b, thereby raising and lowering the sealing head 12. During the sealing process, with the sealing head 12 at the processing position X1, the cylinders 26a and 26b are driven to extend the shafts 24a and 24b, pressing the sealing surface 20 against the sealing portion 6 of the laminated films 2a and 2b. The sealing head 12 is heated by the heater, and the sealing surface 20 is pressed against the sealing portion 6 of the films 2a and 2b, thereby heat-sealing the sealing portion 6.

[0080] The first cooling head Z-direction movement control unit 94c drives the cylinders 46a and 46b to extend and retract the shafts 44a and 44b, thereby raising and lowering the first cooling head 14. After the sealing process, with the first cooling head 14 at the processing position X1, the cylinders 46a and 46b are driven to extend the shafts 44a and 44b, pressing the pressing surface 40 against the welded seal portion 6. The first cooling head 14 is cooled by the cooling element, and the pressing surface 40 is pressed against the seal portion 6, thereby cooling the seal portion 6.

[0081] The second cooling head Z-direction movement control unit 94d drives the cylinder 66 to extend and retract the shaft 64, thereby raising and lowering the second cooling head 16. Prior to the sealing process, when the second cooling head 16 is at the processing position X1, the cylinder 66 is driven to extend the shaft 64, pressing the pressing surface 60 against the object 1 via the film 2b. The second cooling head 16 is cooled by the cooling element, and the pressing surface 60 is pressed against the object-side region 8, thereby cooling the object 1 via the film 2b.

[0082] Furthermore, the control unit 90 controls the temperatures of the sealing head 12 , the first cooling head 14 , and the second cooling head 16 to predetermined temperatures through the temperature control unit 96 .

[0083] The temperature control unit 96 includes a sealing head temperature control unit 96a, a first cooling head temperature control unit 96b, and a second cooling head temperature control unit 96c. The sealing head temperature control unit 96a controls the temperature of the sealing head 12. The first cooling head temperature control unit 96b controls the temperature of the first cooling head 14. The second cooling head temperature control unit 96c controls the temperature of the second cooling head 16.

[0084] The sealing head temperature control unit 96a compares the temperature of the sealing head 12 detected by the temperature sensor 21 provided in the sealing head 12 with the set temperature of the sealing head 12 stored as setting information in the memory 92, and adjusts the heater to control the temperature of the sealing head 12 so that the temperature reaches the set temperature. The set temperature of the sealing head 12 is, for example, approximately 100°C to 200°C.

[0085] The first cooling head temperature control unit 96b compares the temperature of the first cooling head 14 detected by the temperature sensor 41 provided in the first cooling head 14 with the set temperature of the first cooling head 14 stored in the memory 92 as setting information, adjusts the cooling element, and controls the temperature of the first cooling head 14 to become the set temperature.

[0086] The second cooling head temperature control unit 96c compares the temperature of the second cooling head 16 detected by the temperature sensor 61 provided in the second cooling head 16 with the set temperature of the second cooling head 16 stored in the memory 92 as setting information, adjusts the cooling element, and controls the temperature of the second cooling head 16 to reach the set temperature.

[0087] The set temperatures of the first cooling head 14 and the second cooling head 16 are, for example, predetermined temperatures, and specifically, can be set to a predetermined temperature of 20° C. or less.

[0088] Next, refer to Figures 7 to 9 The heat sealing procedure using the heat sealing device 10 will be described. Figure 7 and Figure 8 It is a process diagram. Figure 9 It is a timing chart showing the movement timing of the sealing head 12 , the first cooling head 14 , and the second cooling head 16 by the moving mechanism 18 .

[0089] First, a stacked body in which the articles 1 are sandwiched between the films 2a and 2b is placed on the heat sealing tray 5 (step S1).

[0090] Next, the laminate is placed in the heat sealing device 10 and placed in the processing position (step S2). At this time, as the initial position, the sealing head 12 and the second cooling head 16 are placed in the processing position X1, and the first cooling head 14 is placed in the second retreat position X2.

[0091] At time t1, the second cooling head 16 is lowered so that it contacts the article-side region 8 of the film 2b (step S3). This presses the second cooling head 16 against the article 1 via the film 2b, cooling the article 1. Cooling the article 1 reduces thermal damage to the article 1 caused by radiant heat from the sealing head 12.

[0092] While the second cooling head 16 is in contact with the film 2b to cool the article 1, at time t2, the sealing head 12 is lowered and brought into contact with the sealing portion 6 to thermally weld the films 2a and 2b (step S4).

[0093] After the heat welding, at time t3, the sealing head 12 is raised to be in a non-contact state with the sealing portion 6 (step S5).

[0094] Next, the sealing head 12 is retracted from the processing position X1 to the first retracted position X0 , and the first cooling head 14 is moved from the second retracted position X2 to the processing position X1 (step S6 ).

[0095] With the first cooling head 14 set at the processing position X1, at time t4, the first cooling head 14 is lowered to come into contact with the welded seal portion 6 to cool the seal portion 6 (step S7).

[0096] After the sealing portion 6 is cooled, at time t5, the first cooling head 14 and the second cooling head 16 are raised to bring the first cooling head 14 into a non-contact state with the sealing portion 6 (step S8).

[0097] As above, the heat sealing process in the heat sealing device 10 is performed.

[0098] In addition to the first cooling head 14 for cooling the sealing portion 6, the heat sealing device 10 of this embodiment also includes a second cooling head 16 for cooling the article side area 8 of the film 2 that is closer to the article side than the sealing portion 6. Therefore, it is possible to increase the processing capacity of heat sealing while suppressing thermal damage to the article 1 packaged by the film 2.

[0099] In this embodiment, the moving mechanism 18 is configured to move the sealing head 12, the first cooling head 14, and the second cooling head 16 relative to the film 2. However, the moving mechanism 18 may also move the article 1 and the film 2 relative to the sealing head 12, the first cooling head 14, and the second cooling head 16. Furthermore, the moving mechanism 18 is configured to move both together.

[0100] Thus, the heat sealing device 10 includes the moving mechanism 18 for moving the sealing head 12 , the first cooling head 14 , and the second cooling head 16 relative to the films 2 a and 2 b , respectively, and the control unit 90 , thereby making it easy to control thermal fusion and cooling.

[0101] The control unit 90 preferably controls the sealing head 12, first cooling head 14, second cooling head 16, and various components of the moving mechanism 18 so that after the moving mechanism 18 brings the second cooling head 16 into contact with the article-side region 8 to initiate cooling of the article-side region 8, the moving mechanism 18 brings the sealing head 12 into contact with the sealing portion 6 to initiate heat fusion of the sealing portion 6. Since cooling of the article-side region 8 by the second cooling head 16 begins before heat fusion, thermal damage to the article 1 caused by the heat of the sealing head 12 can be reduced compared to a case where both the sealing head 12 and the second cooling head 16 are brought into contact with the films 2a and 2b simultaneously to initiate heat fusion of the sealing portion 6 and cooling of the article-side region 8. However, the second cooling head 16 and the sealing head 12 may be lowered simultaneously to initiate cooling of the article-side region and heat fusion of the sealing portion almost simultaneously.

[0102] Furthermore, in the above process, the first cooling head 14 and the second cooling head 16 are raised simultaneously, but they may be raised sequentially. In addition, the first cooling head 14 may be raised first and then the second cooling head 16, or the second cooling head 16 may be raised first and then the first cooling head 14.

[0103] In this embodiment, the control unit 90 controls the sealing head 12, the first cooling head 14, the second cooling head 16, and the moving mechanism 18 so that after heat fusion is performed by the sealing head 12, the moving mechanism 18 retracts the sealing head 12 from the sealing portion 6 and the moving mechanism 18 brings the first cooling head 14 into contact with the sealing portion 6. By providing such a control unit 90, the heat-fused sealing portion 6 can be quickly cooled, thereby increasing the heat sealing throughput.

[0104] Furthermore, as in the present embodiment, the control unit 90 preferably controls the sealing head 12, the first cooling head 14, the second cooling head 16, and the moving mechanism 18 so that the second cooling head 16 continues to cool the article-side region 8 from the start of heat fusion bonding of the sealing portion 6 by the sealing head 12 until the completion of cooling of the sealing portion 6 by the first cooling head 14. Since the second cooling head 16 continues to cool from the start of heat fusion bonding until the completion of cooling by the first cooling head 14, the cooling effect on the article 1 can be maintained, compared to a case where cooling by the second cooling head 16 is stopped before the completion of cooling by the first cooling head 14, thereby reducing thermal damage to the article 1.

[0105] In the heat sealing device 10 of this embodiment, the first cooling head 14 and the second cooling head 16 are equipped with temperature sensors 41 and 62, respectively, and cooling elements, and are controlled by the control unit 90 to maintain preset temperatures. However, as long as the first cooling head 14 can cool the sealed portion 6 after heat fusion, it may not have the temperature sensor 41 and the cooling element, or may have only the cooling element. Similarly, as long as it can prevent thermal damage to the article 1 caused by radiant heat from the sealing head 12, the second cooling head 16 may not have the temperature sensor 61 and the cooling element, or may have only the cooling element.

[0106] In the present heat sealing device 10, the second cooling head Z-direction movement control unit 94d preferably controls the pressing pressure applied when the second cooling head 16 contacts the article-side region. In this example, the second cooling head 16 is pressed against the article 1. In this embodiment, the second cooling head Z-direction movement unit 68 further includes a load sensor 67 for detecting the pressing pressure. The second cooling head Z-direction movement control unit 94d can control the pressing pressure based on the signal from the load sensor 67. By controlling the pressing pressure applied when the second cooling head 16 contacts the article-side region, the amount of drive of the cylinder 66 can be controlled so that the pressing pressure applied to the article 1 does not exceed a predetermined set value. This prevents excessive pressing pressure on the article 1 and reduces damage to the article 1.

[0107] In addition, not only the second cooling head Z-direction movement control unit 94d, but also the sealing head Z-direction movement control unit 94b preferably controls the pressing pressure when the sealing head 12 is brought into contact with the sealing portion 6. In this case, the sealing head Z-direction movement unit 28 can be configured to include a load sensor, and the sealing head Z-direction movement control unit 94b controls the pressing pressure based on the signal from its load sensor. Similarly, the first cooling head Z-direction movement control unit 94c preferably controls the pressing pressure when the first cooling head 14 is brought into contact with the sealing portion 6. In this case, the first cooling head Z-direction movement unit 48 can be configured to include a load sensor, and the first cooling head Z-direction movement control unit 94c controls the pressing pressure based on the signal from its load sensor.

[0108] In the above embodiment, if Figure 6 As shown, when cooling the article-side region 8, the pressing surface 60 of the second cooling head 16, which presses the films 2a and 2b in the article-side region 8, is positioned facing the entire surface of the article 1. This allows the entire surface of the article 1 to be cooled, effectively preventing thermal damage to the article 1. This is particularly effective when packaging heat-sensitive articles. Figure 10 FIG is an enlarged view showing the end of the article 1 and the end of the sealing head 12 and the second cooling head 16. Figure 10 As shown, in this embodiment, the second cooling head 16 presses the article-side region of the films 2a and 2b so that the end surface 16e on the sealing head 12 side of the pressing surface 60 is aligned with the end surface 1e on the sealing head 12 side of the article 1. The end surface 1e closest to the sealing head 12 is susceptible to thermal damage in the article 1. However, in this example, the pressing surface 60 of the second cooling head 16 is positioned facing the entire surface of the article 1, and the second cooling head 16 cools the entire end of the article 1, resulting in a high degree of thermal damage suppression.

[0109] However, if the second cooling head 16 can cool at least a portion of the article-side region 8 that is closer to the article 1 than the sealing portion 6, thermal damage to the article can be suppressed. In other words, the technology of the present invention includes the case where the pressing surface 60 of the second cooling head 16 is not positioned facing the entire surface of the article 1.

[0110] For example, Figure 11 As shown, the end surface 16e of the second cooling head 16 can be further away from the sealing head 12 than the end surface 1e of the article 1, that is, D>d1. However, from the perspective of effectively suppressing thermal damage, the smaller the difference D-d1 between the distance D between the second cooling head 16 and the sealing head 12 and the distance d1 between the end surface 1e of the article 1 and the sealing head 12, the better.

[0111] In addition, if Figure 12As shown, it is particularly preferred that the end surface 16e of the second cooling head 16 is located closer to the sealing head 12 side than the end surface 1e of the article 1, with D < d1. That is, when cooling the article-side region 8, the end position of the pressing surface 60 of the second cooling head 16, which presses the films 2a and 2b, on the sealing head 12 side of the article-side region 8, is preferably closer to the sealing head 12 side than the end position of the article 1 on the sealing head 12 side. When cooling the article-side region, the end position of the pressing surface 60 of the second cooling head 16 on the sealing head 12 side is closer to the sealing head 12 side than the end position of the article 1 on the sealing head 12 side, thereby more effectively suppressing thermal damage to the article.

[0112] Hereinafter, a modified example of the design of the second cooling head 16 will be described.

[0113] Figure 13 1 is a plan view showing the positional relationship between the second cooling head 16A and the sealing head 12 and the article 1 of the design modification 1, and the lower figure is a cross-sectional view taken along line 13B-13B. Figure 13 As shown, the second cooling head 16A has a rectangular shape similar to the sealing head 12. When cooling the article-side region 8, the pressing surface 60A of the second cooling head 16A, which presses the films 2a and 2b in the article-side region 8, does not face the article 1, but is positioned so as to surround the periphery of the article 1. The pressing surface 60A of the second cooling head 16A is located in the article-side region 8, closer to the article than the sealing portion 6. This prevents the propagation of radiant heat from the sealing head 12 positioned in the sealing portion 6 to the article. This allows for indirect cooling of the article 1 by positioning the second cooling head 16A around the periphery of the article 1, even when the second cooling head 16A is not used to directly cool the article 1, thereby minimizing thermal damage to the article 1.

[0114] Figure 14 The figure below is a plan view showing the positional relationship between the second cooling head 16B, the sealing head 12 and the article 1 of the design modification 2, and the figure below is a cross-sectional view taken along line 14B-14B. Figure 14 As shown, the second cooling head 16B has a rectangular shape similar to the sealing head 12. When cooling the article-side region 8, the pressing surface 60B of the second cooling head 16B, which presses the films 2a and 2b in the article-side region 8, is preferably positioned at least opposite the outer periphery of the article 1. Since the pressing surface 60B of the second cooling head 16B is positioned at least opposite the outer periphery of the article 1, thermal damage to the article 1 can be suppressed compared to a case where the pressing surface 60B of the second cooling head 16B is not opposed to the article 1.

[0115] Figure 15 This is a diagram showing the second cooling head 16C of the third design variation, showing an enlarged view of the end of the article 1 and the end of the sealing head 12 and the second cooling head 16C. Figure 15As shown, the second cooling head 16C has a stepped portion 16f at its end. Specifically, the pressing surface 60C of the second cooling head 16C protrudes from the sealing head 12 side relative to the object 1 side, with the position opposite the outer periphery of the object 1 being the reference S. This protrusion from the sealing head 12 side relative to the object 1 side also suppresses radiant heat from the sealing head 12 that circulates from below the second cooling head 16C. This results in a higher thermal damage suppression effect compared to a case where the pressing surface 60C does not protrude at its end.

[0116] Figure 16 1 is a diagram showing the second cooling head 16D of the fourth design modification, showing the end of the article 1 and the end of the sealing head 12 and the second cooling head 16D in an enlarged manner. Figure 16 As shown, the second cooling head 16D has a tapered portion 16g that protrudes more toward the end. That is, similar to the second cooling head 16C, the pressing surface 60D of the second cooling head 16D protrudes further toward the sealing head 12 than toward the object 1, with the position facing the outer periphery of the object 1 as a reference S. Therefore, the second cooling head 16D can also suppress radiant heat from the sealing head 12 that circulates from below the second cooling head 16D, thereby achieving a higher thermal damage suppression effect compared to a case where the pressing surface 60D does not protrude at the end.

[0117] In each of the above-described embodiments, various processors described below can be used as the hardware configuration of the processing units (processing units) that execute various processes, such as the control unit 90, the movement control unit 94, and the temperature control unit 96. As described above, various processors include general-purpose CPUs that execute software and function as various processing units, as well as processors whose circuit configuration can be modified after manufacturing, such as FPGAs (Field Programmable Gate Arrays), programmable logic devices (PLDs), and processors with circuit configurations specifically designed to execute specific processes, such as ASICs (Application Specific Integrated Circuits).

[0118] A processing unit may be composed of one of these various processors, or a combination of two or more processors of the same or different types (e.g., a combination of multiple FPGAs and / or a combination of a CPU and an FPGA). Furthermore, multiple processing units may be composed of one processor.

[0119] As an example of a processor being used to configure multiple processing units, one method involves combining one or more CPUs with software to form a single processor, with the processor functioning as multiple processing units. A second method involves a processor that uses a single integrated circuit (IC) chip, such as a system on a chip (SoC), to implement the overall functionality of a system containing multiple processing units. In this way, various processing units are configured using one or more of the aforementioned processors as a hardware configuration.

[0120] Furthermore, as the hardware configuration of these various processors, more specifically, a circuit (circuitry) formed by combining circuit elements such as semiconductor elements can be used.

[0121] From the above description, the techniques described in the following supplementary notes can be understood.

[0122] [Supplementary Note 1]

[0123] A heat sealing device for sealing, by heat welding, a film used for packaging an article and arranged to sandwich the article and partially overlap around the article, the heat sealing device comprising:

[0124] a sealing head that heat-seals the sealed portion of the film;

[0125] a first cooling head for cooling the sealed portion after heat welding by the sealing head; and

[0126] a second cooling head for cooling at least a portion of an article-side region of the film that is closer to the article than the sealing portion;

[0127] a moving mechanism for moving the sealing head, the first cooling head, and the second cooling head relative to the film; and

[0128] processor,

[0129] The processor is configured to control the sealing head, the first cooling head, the second cooling head, and each part of the moving mechanism.

[0130] The entire disclosure of Japanese Patent Application No. 2021-026600 filed on February 22, 2021 is incorporated into this specification by reference.

[0131] All documents, patent applications, and technical standards mentioned in this specification are hereby incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. A heat sealing device for sealing a film used for packaging an article by heat welding, the film being arranged to sandwich the article and partially overlap around the article, wherein: The heat sealing device comprises: a sealing head for heat-melting the sealed portion of the film; a first cooling head for cooling the sealing portion after the sealing head performs heat welding; a second cooling head that cools at least a portion of an article-side region of the film that is closer to the article than the sealing portion and is separate from the first cooling head; a moving mechanism for moving the sealing head, the first cooling head, and the second cooling head relative to the film; and a control unit that controls the sealing head, the first cooling head, the second cooling head, and each unit of the moving mechanism; The control unit continues cooling the article-side region by the second cooling head during a period from when thermal fusion of the sealed portion by the sealing head is started to when cooling of the sealed portion by the first cooling head is completed.

2. The heat sealing device according to claim 1, wherein: After the control unit starts cooling the article-side region by bringing the second cooling head into contact with the article-side region using the moving mechanism, the control unit starts thermal welding of the sealing portion by bringing the sealing head into contact with the sealing portion using the moving mechanism.

3. The heat sealing device according to claim 2, wherein: After the sealing head performs heat fusion bonding, the control unit uses the moving mechanism to retract the sealing head from the sealing portion and uses the moving mechanism to bring the first cooling head into contact with the sealing portion.

4. The heat sealing device according to any one of claims 1 to 3, wherein: The control unit controls the temperature of at least one of the first cooling head and the second cooling head to a preset temperature.

5. The heat sealing device according to claim 4, wherein: The preset temperature is below 20°C.

6. The heat sealing device according to any one of claims 1 to 3, wherein: The control unit controls a pressing pressure applied to the contact region when the second cooling head is brought into contact with the article-side region.

7. The heat sealing device according to any one of claims 1 to 3, wherein: When cooling the article side region, the second cooling head has an end portion on the sealing head side of a pressing surface pressing the article side region of the film positioned closer to the sealing head than an end portion of the article on the sealing head side.

8. The heat sealing device according to any one of claims 1 to 3, wherein: When cooling the article-side region, the second cooling head has a pressing surface that presses the film on the article-side region disposed at a position facing at least the outer peripheral edge of the article.

9. The heat sealing device according to claim 8, wherein: When cooling the article-side region, the second cooling head has a pressing surface that presses the film on the article-side region disposed at a position facing the entire surface of the article.

10. The heat sealing device according to claim 8, wherein: The sealing head side of the pressing surface protrudes more than the article side, with respect to a position of the pressing surface facing the outer peripheral edge of the article.

11. The heat sealing device according to any one of claims 1 to 3, wherein: When the width of the sealing head is LH and the distance between the sealing head and the second cooling head is D, the relationship between D and LH is LH / 1000<D<10LH.

12. The heat sealing device according to any one of claims 1 to 3, wherein: When the width of the sealing head is LH and the width of the first cooling head is LC, the relationship between LH and LC is LH / 2<LC.

13. The heat sealing device according to any one of claims 1 to 3, wherein: The sealing portion is provided so as to surround the entire circumference of the article. The sealing head is also formed in a frame shape corresponding to the shape of the sealing portion.

14. The heat sealing device according to claim 1, wherein: The moving mechanism does not have a function of moving the film, but includes a mechanism for horizontally moving the sealing head and the first cooling head, and a mechanism for vertically moving the sealing head, the first cooling head, and the second cooling head.

Images