Horizontal sealing device

Abstract

To provide a lateral seal device which has an upper seal part and a lower seal part with excellent sealing performance, and with which packaging bags with a back adhesion part can be manufactured.SOLUTION: A lateral seal device for heat-sealing a cylindrical film f3 which has a joint portion F2 formed by laminating the side edges of a film material F together and a tubular body F1 including a rear surface where the joint portion is formed and a front surface on the opposite side of the rear surface, has a rear-side seal-forming portion 44 and a front-side seal-forming portion 45. The rear-side seal-forming portion has a heater elastic layer 61 that is in contact with the rear surface of the cylindrical film, and a support plate 51. A surface 61a of the heater elastic layer has, on the rear surface of the cylindrical film, a first region S11 in contact with an overlapping portion F3 formed by overlapping the joint portion and the cylindrical body, and a second region S12 adjacent to the first region S11 and in contact with the cylindrical body. The heater elastic layer has a step absorbing portion 64 that is thicker in the first region than the heater elastic layer in the second region.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a horizontal sealing device.

Background Art

[0002] There is known a packaging bag that contains contents such as drugs and foods inside a cylindrical body including a back-attachment portion formed by bonding the side edges of a single film material together, and closes the upper and lower ends of the cylindrical body. This type of packaging bag is manufactured using, for example, a packaging and filling machine as shown in Patent Document 1.

[0003] Specifically, first, while arranging a part of a long film material continuously fed out along the vertical direction and overlapping the side edges so as to form a cylinder, the overlapping portion is heat-welded (longitudinal seal) by a longitudinal sealing device provided in the packaging and filling machine, thereby forming a cylindrical film including the joined portion. Then, the lower portion of the cylindrical film is heat-welded (horizontal seal) by a horizontal sealing device provided in the packaging and filling machine, thereby forming a bag-shaped film including the joined portion with the lower side closed and the upper side open. Then, after filling a predetermined amount of the content portion into the bag-shaped film using a filling device provided in the packaging and filling machine, the upper open portion is heat-welded (horizontal seal) by the horizontal sealing device, thereby obtaining a packaging bag.

[0004] Such a packaging bag includes a main body portion having a sealed bag-shaped storage portion for storing contents, an upper seal portion connected to the upper end of the storage portion, and a lower seal portion connected to the lower end of the storage portion, and a belt-shaped back-attachment portion connected to the main body portion and continuously formed from the upper seal portion to the lower seal portion. The back-attachment portion is formed by the joined portion of the cylindrical film and is usually formed on the back side of the main body portion so as not to protrude outside the main body portion when viewed from the front side.

[0005] The horizontal sealing device includes a pair of heat blocks that can be opened and closed, and by sandwiching a predetermined portion of the above-described cylindrical film between them and heat-welding, the upper seal portion and the lower seal portion of the packaging bag are formed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] When forming the upper seal portion and the lower seal portion of the packaging bag, the heater block of the horizontal sealing device sandwiches the portion where the front film material and the back film material in the tubular film overlap, and at the same time sandwiches the joining portion on the back side. That is, the heater block sandwiches both the thin portion where the two front and back film materials overlap and the thick portion where the two film materials that make up the joining portion together with the two front and back film materials overlap (the portion where a total of four film materials are overlapped).

[0008] Therefore, between the above-mentioned thin portion and the thick portion, since the thick portion preferentially comes into contact with the heater block and is clamped, the force of the heater block to clamp the thin portion tends to be weak. In particular, the force to clamp the vicinity of the boundary with the thick portion (the back pasting portion) in the thin portion tends to be weak. Therefore, there has been a risk that the sealing performance of the upper seal portion and the lower seal portion of the finally obtained packaging bag becomes non-uniform in the width direction.

[0009] An object of the present invention is to provide a horizontal sealing device capable of manufacturing a packaging bag with a back pasting portion having an upper seal portion and a lower seal portion excellent in sealing performance.

Means for Solving the Problems

[0010] <1> A horizontal sealing device for heat-sealing film materials on the front side and the back side that are overlapped with each other while sandwiching a cylindrical film having a joined portion where side edges of the film material are joined together, a back surface on which the joined portion is formed, and a front surface on the opposite side of the back surface. The horizontal sealing device includes a back-side seal forming portion that presses the back surface of the cylindrical film and a front-side seal forming portion that presses the front surface of the cylindrical film. The back-side seal forming portion has a heater elastic layer that contacts the back surface of the cylindrical film and a support plate that supports the heater elastic layer. The surface of the heater elastic layer has a first region that contacts an overlapping portion formed by the overlap of the joined portion and the cylindrical body among the back surfaces of the cylindrical film, and a second region that is adjacent to the first region and contacts the cylindrical body. The heater elastic layer is provided with a step absorption portion having a greater thickness than the heater elastic layer in the second region in the first region. The horizontal sealing device is characterized by this.

[0011] <2> The horizontal sealing device according to <1>, wherein the heater elastic layer includes a basic elastic layer having a predetermined thickness and an additional elastic layer having a predetermined thickness laminated on the basic elastic layer in the first region.

[0012] <3> The horizontal sealing device according to <2>, wherein the support plate includes a housing portion for housing the additional elastic layer.

[0013] <4> The back-side seal forming portion includes a first unit having the additional elastic layer and a first support plate that supports the additional elastic layer and constitutes the support plate, and a second unit having the basic elastic layer and a second support plate that supports the basic elastic layer, constitutes the support plate together with the first support plate, and has an opening for forming a housing portion for housing the additional elastic layer, and the additional elastic layer is housed in the opening and overlaps the first support plate. The horizontal sealing device according to <3>.

Advantages of the Invention

[0014] According to the present invention, it is possible to provide a horizontal sealing device capable of manufacturing a packaging bag with a back sticking portion, which has an upper sealing portion and a lower sealing portion excellent in sealing performance.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Modes for Carrying Out the Invention

[0016] <Embodiment 1> Hereinafter, a vertical multi-column filling and packaging machine 10 equipped with a horizontal sealing device 1 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 14. FIG. 1 is a right side view of a vertical multi-column filling and packaging machine 10 equipped with a horizontal sealing device 1 according to Embodiment 1. The vertical multi-column filling and packaging machine 10 (hereinafter, may be simply referred to as "packaging machine 10") continuously manufactures stick-shaped packaging bags P filled with contents such as food and pharmaceuticals over six columns. Note that the left side of FIG. 1 will be described as the front side of the packaging machine 10, and the right side of FIG. 1 will be described as the back side of the packaging machine 10.

[0017] The packaging machine 10 includes a main body frame 11 and a film supply device 12 installed at a lower position on the back side thereof. The main body frame 11 is a member that supports each component such as the horizontal sealing device 1 included in the packaging machine 10. The film supply device 12 supplies the base film f0 from a roll-shaped packaging material roll Fr. A rotary shaft 12a driven by a motor is installed at the center of the packaging material roll Fr, and when the rotary shaft 12a rotates, the base film f0 is fed out from the packaging material roll Fr at a predetermined speed.

[0018] The base film f0 supplied from the film supply device 12 is conveyed while passing through a roll group 13 having a plurality of rolls to absorb slack, and then goes up the back side of the main body frame 11. Then, further, the base film f0 passes through the upper surface side of the main body frame 11 and is supplied to a packaging bag forming mechanism portion 20 provided on the front side of the main body frame 11.

[0019] The packaging bag forming mechanism portion 20 includes a slitter device 21, a former device 22, a vertical sealing device 23, a horizontal sealing device 1, a filling device 24, a cutter device 25, and the like. The above-described base film f0 is supplied to the packaging bag forming mechanism portion 20, and when the base film f0 passes through the packaging bag forming mechanism portion 20 from the upper side to the lower side, it is divided into six columns, and stick-shaped packaging bags P are continuously manufactured.

[0020] FIG. 2 is an explanatory diagram schematically showing the process in which the packaging bag P is formed by passing through the packaging bag forming mechanism section 20. As shown in FIGS. 1 and 2, the slitter device 21 includes a pair of upper and lower rotating shafts 21a provided with five rotating cutters at regular intervals. When the original film f0 passes between those rotating shafts 21a, it is cut in parallel to the length direction and becomes a long divided film f2 divided into six rows. For the sake of convenience of explanation, only a part of the slitter device 21 is shown in FIG. 2.

[0021] The former device 22 is a device for forming each divided film f2 into a cylindrical shape. The former device 22 includes a plurality of former pipes 22a assigned to each divided film f2 one by one. The former pipes 22a are arranged generally along the vertical direction, and the lower end side of the former pipe 22a is inserted into a cylindrical seal portion 23a provided in the vertical seal device 23 described later with a clearance. The divided film f2 is wound around the former pipe 22a in a cylindrical shape from the outside. The former pipe 22a also functions as a supply pipe for the contents. For the sake of convenience of explanation, only a part of the plurality of former pipes 22a is shown in FIG. 2.

[0022] The vertical seal device 23 is a device for sealing (heat welding) the portion where the side edges of the cylindrical divided film f2 are overlapped to form a cylindrical film f3. The vertical seal device 23 includes a cylindrical seal portion 23a and a vertical seal block 23b that drives forward and backward with respect to the cylindrical seal portion 23a. The cylindrical seal portion 23a is fixed to the main body frame 11 side along the vertical direction. An opening groove along the vertical direction is formed on the front side of the cylindrical seal portion 23a.

[0023] As described above, after the cutting film f2 is wound cylindrically around the former pipe 22a, when passing through the clearance between the former pipe 22a and the cylindrical seal part 23a, both ends (side edges) in the width direction of the cutting film f2 are overlapped, and the overlapped part (hereinafter referred to as the "overlapped part") protrudes from the opening groove of the cylindrical seal part 23a. A receiving surface is formed on the surface of the cylindrical seal part 23a adjacent to the opening groove. The longitudinal seal block 23b is heated to an appropriate temperature, and the overlapped part protruding from the opening groove is pressed against the receiving surface of the cylindrical seal part 23a, thereby sealing (heat welding) the overlapped part. In this way, a cylindrical film f3 having an overlapped part F2 is formed from the cutting film f2.

[0024] The transverse seal device 1 is a device for sealing (heat welding) the cylindrical film f3 in a manner crossing the width direction. The details of the transverse seal device 1 will be described later.

[0025] The filling device 24 has a supply port 24a protruding from the upper end of the former pipe 22a that forms part of the former device 22 described above, and a connection chute 24b is connected to the upper end thereof. The contents stored in a hopper (not shown) are metered and input into the connection chute 24b. The input predetermined amount of the contents passes through the connection chute 24b and the former pipe 22a and is supplied downward.

[0026] The cutter device 25 is a device for cutting a packaging bag row in which a plurality of packaging bags P are connected in a row and supplied from the transverse seal device 1 side to individualize the packaging bags P. The cutter device 25 includes a movable blade 25a and a fixed blade 25b arranged opposite to each other, and the movable blade 25a is configured to be pressed against the fixed blade 25b as the piston rod of the air cylinder extends. When the movable blade 25a is pressed against the fixed blade 25b, the packaging bag row is cut between the lowermost packaging bag P and another packaging bag P connected above it. The cutting by the cutter device 25 is performed collectively on six packaging bag rows.

[0027] Note that, as shown in FIG. 1, a guide body 26 is provided above the cutter device 25, by which the posture (orientation) of the packaging bag series before being supplied to the cutter device 25 is adjusted. Further, below the cutter device 25, discharge chutes 27 for receiving the cut and individualized packaging bags P and discharging them onto a conveying means (conveyor) (not shown) are provided for each row.

[0028] Here, the packaging bag P manufactured by the packaging machine 10 will be described with reference to FIGS. 3 to 5. FIG. 3 is a front view of the packaging bag P, FIG. 4 is a rear view of the packaging bag P, and FIG. 5 is a cross-sectional view taken along line A-A of FIG. 3. For the sake of convenience of explanation, the left side of FIG. 3 is defined as the left side of the packaging bag P, and the right side of FIG. 3 is defined as the right side of the packaging bag P.

[0029] The packaging bag P is formed from a single film material F having a vertically long substantially rectangular shape. The film material F is made of, for example, an aluminum vapor-deposited film excellent in light-shielding property, gas barrier property, etc. In other embodiments, a film material other than the aluminum vapor-deposited film (for example, a composite film of aluminum foil, a composite resin film such as PET resin or nylon resin) may be used. Note that the inner surfaces of the film material F that constitute the inner surface of the packaging bag P are thermally weldable to each other, and the outer surfaces of the film material F that constitute the outer surface of the packaging bag P are not thermally welded to each other.

[0030] Overall, the packaging bag P has a shape in which the upper and lower ends of a cylindrical body F1 formed by bonding the side edges of the film material F together in a strip shape are closed. Such a packaging bag P includes a storage portion 32, an upper seal portion 33, a lower seal portion 34, a back sticker portion 35, a notch portion 36, and the like.

[0031] The accommodating portion 32 is a bag-shaped portion that accommodates the contents S. The upper end 32a of the accommodating portion 32 is closed (sealed) by the upper seal portion 33, and the lower end 32b of the accommodating portion 32 is closed (sealed) by the lower seal portion 34. The upper seal portion 33 is formed in the manufacturing process and is a portion formed by heat welding with a horizontal sealing device 1 in a state where the film materials F on the front side and the back side are overlapped at the upper end of the cylindrical body F1 (cylindrical film f3) having the joining portion F2, and generally forms a flat sheet shape. Also, the lower seal portion 34 is formed in the manufacturing process and is a portion formed by heat welding with the horizontal sealing device 1 in a state where the film materials F on the front side and the back side are overlapped at the lower end of the cylindrical body F1 having the joining portion F2, and generally forms a flat sheet shape.

[0032] The upper end 32a of the accommodating portion 32 (the upper boundary portion in contact with the upper seal portion 33) has a curved portion that rises from the left side to the right side as viewed from the front side, as shown in FIG. 3. Such an accommodating portion 32 includes a cylindrical accommodating main body portion 321 and a narrow-width portion 322 that extends upward from the upper end of the accommodating main body portion 321. The accommodating main body portion 321 is formed of the cylindrical portion of the cylindrical film f3 (cylindrical body F1) and has the same width as the width of the packaging bag P (the width of the cylindrical body F1). The narrow-width portion 322 is formed of a portion narrower than the width of the accommodating main body portion 321 (the width of the cylindrical body F1), and the width gradually narrows from the lower side to the upper side. As shown in FIG. 3, as viewed from the front side, the narrow-width portion 322 is offset to the right in the width direction of the packaging bag P. Such a narrow-width portion 322 is aligned (adjacent) with a part of the upper seal portion 33 in the width direction of the packaging bag P. The narrow-width portion 322 is the portion to be cut when the packaging bag P is opened, and a notch portion (cut) 36 used at the time of opening is formed in the upper seal portion 33 on the left side of the narrow-width portion 322. The contents S in the accommodating portion 32 are discharged to the outside from the narrow-width portion 322 cut at the time of opening. The upper seal portion 33 includes a portion above the narrow-width portion 322, a portion below that portion, and a portion adjacent in the width direction to the narrow-width portion 322.

[0033] The lower end 32b of the accommodating portion 32 (the lower boundary portion in contact with the lower seal portion 34) has a shape extending along the width direction. The lower seal portion 34 has a generally strip-like shape extending in the width direction (left-right direction) when viewed from the front side.

[0034] The back sticker portion 35 is formed by the portion sealed (heat welded) by the above-described longitudinal sealing device 23 in a state where the side edges in the longitudinal direction of the film material F are overlapped, and has a strip-like shape extending in the vertical direction. The back sticker portion 35 protrudes from the accommodating portion 32, the upper seal portion 33, and the lower seal portion 34 on the back side. The back sticker portion 35 is folded down to the left side (right side when viewed from the back side) when viewed from the front side, and is overlapped with the accommodating portion 32, the upper seal portion 33, and the lower seal portion 34 on the back side. Incidentally, the back sticker portion 35 is composed of the joining portion F2 of the tubular film f3.

[0035] Next, the transverse sealing device 1 will be described with reference to FIGS. 6 to 14. FIG. 6 is a right side view of the transverse sealing device 1. The left side of FIG. 6 is the front side of the transverse sealing device 1, and the right side of FIG. 6 is the rear side of the transverse sealing device 1. As shown in FIG. 6, the transverse sealing device 1 includes transverse sealing units 1A and 1B provided in the base frame 41 in pairs in the front-rear direction and openable and closable in the front-rear direction. One transverse sealing unit 1A is arranged on the front side, and the other transverse sealing unit 1B is arranged on the rear side. Such transverse sealing units 1A and 1B each include heater blocks 42 and 43. The heater block 42 included in the transverse sealing unit 1A and the heater block 43 included in the transverse sealing unit 1B are arranged to face each other in the front-rear direction. A rear side seal forming portion 44 is formed on the facing surface 42a of the heater block 42, and a front side seal forming portion 45 is formed on the facing surface 43a of the heater block 43.

[0036] The heater blocks 42 and 43 are made of metal and are generally in the shape of a prism extending in the left-right direction (the front-back direction of the paper). Inside the heater blocks 42 and 43, heater terminals (not shown) are provided respectively. When these heater terminals generate heat, the back seal forming portions 44 and the front seal forming portions 45 attached to each of the heater blocks 42 and 43 are heated.

[0037] Also, control thermocouples (not shown) are provided in the heater blocks 42 and 43 respectively. The temperatures of the heater blocks 42 and 43 are measured by these control thermocouples, and based on the measurement results, the temperatures of the heater blocks 42 and 43 are controlled by a control device (not shown) so as to be maintained at a predetermined temperature.

[0038] FIG. 7 is a top view schematically showing the configurations of the horizontal seal units 1A and 1B provided in the horizontal seal device 1. The rear side of the horizontal seal device 1 is shown above FIG. 7, and the front side of the horizontal seal device 1 is shown below FIG. 7. The horizontal seal device 1 forms seal portions (upper seal portion 33 and lower seal portion 34) of the packaging bag P in a form crossing in the width direction with respect to the tubular film f3 by sandwiching the tubular film f3 arranged between the horizontal seal units 1A and 1B between the back seal forming portion 44 and the front seal forming portion 45.

[0039] The tubular film f3 is composed of a tubular body F1 extending in the vertical direction and a joining portion F2 connected to the tubular body F1 and extending in a strip shape in the vertical direction. In the tubular film f3 supplied from the longitudinal seal device 23 side, the joining portion F2 is formed on the tubular body F1 on the side facing the back seal forming portion 44. In this specification, among the tubular film f3, the portion facing the front seal forming portion 45 side is defined as the front f3a of the tubular film f3, and the portion facing the back seal forming portion 44 side is defined as the back f3b of the tubular film. The joining portion F2 is arranged on the back f3b side of the tubular film f3.

[0040] The horizontal sealing device 1 forms seal portions (upper seal portion 33 and lower seal portion 34) all at once for a plurality (six) of cylindrical films f3 arranged in a row in the left - right direction between the horizontal seal units 1A and 1B. The horizontal seal units 1A and 1B are driven to close so as to sandwich the cylindrical film f3 while approaching each other at a predetermined timing, and to open while moving away from each other.

[0041] When forming the upper seal portion 33 and the lower seal portion 34 of the packaging bag P, the front - side seal forming portion 45 is a member that presses the front surface f3a of the cylindrical film f3 (cylindrical body F1) at a location corresponding to the front surface 33a of the upper seal portion 33 and the front surface 34a of the lower seal portion 34 (see FIG. 3) while being heated by the heater block 43, between it and the opposing back - side seal forming portion 44. Such a front - side seal forming portion 45 generally has a plate - like shape extending in the left - right direction, and includes a support plate 46 arranged on the side of the opposing surface 43a of the heater block 43, and a metal contact portion 47 fixed on the surface 46a of the support plate 46 and contacting the front surface f3a of the cylindrical film f3 (cylindrical body F1).

[0042] The support plate 46 is made of a metal plate (for example, iron - made) having a predetermined thickness while extending in the left - right direction, and is fixed to the opposing surface 43a of the heater block 43 using attachment means such as screws. The surface 46a of the support plate 46 facing the back - side seal forming portion 44 side is flat, and the contact portion 47 is fixed on the flat surface 46a. A plurality of contact portions 47 are provided on the support plate 46, and these contact portions 47 are assigned one by one to the corresponding cylindrical films f3.

[0043] The contact portion 47 has a plate - like shape made of metal (for example, iron - made) having a predetermined thickness, and a contact surface 47a that contacts the back surface f3b of the cylindrical film f3 is formed on the side facing the back - side seal forming portion 44. The contact surface 47a is flat and is adjusted to a size larger than the back surface f3b of the cylindrical film f3. The contact portion 47 is fixed to the support plate 46 by welding or the like so that the contact surface 47a faces the back - side seal forming portion 44 side.

[0044] When forming the upper seal portion 33 and the lower seal portion 34 of the packaging bag P, the back side seal forming portion 44 is a member that sandwiches and presses the back surface f3b of the tubular film f3 (tubular body F1) at a position corresponding to the back surface 33b of the upper seal portion 33 and the back surface 34b of the lower seal portion 34 (see FIG. 4) between itself and the opposing front side seal forming portion 45 while being heated by the heater block 42. Such a back side seal forming portion 44 generally has a plate shape extending in the left-right direction, and includes a support plate 51 disposed on the side of the opposing surface 42a of the heater block 42 and a heater elastic layer 61 disposed on the surface 51a side of the support plate 51.

[0045] The back side seal forming portion 44 of the present embodiment is formed by overlapping and combining two parts (units). The back side seal forming portion 44 includes a first unit U1 disposed on the side of the opposing surface 42a of the heater block 42 and a second unit U2 superimposed on the first unit U1. For convenience of explanation, the side facing the front side seal forming portion 45 (the rear side of the horizontal seal device 1) is defined as the front of the back side seal forming portion 44, and the opposite side is defined as the back (rear surface) of the back side seal forming portion 44.

[0046] FIG. 8 is a front view of the first unit U1, and FIG. 9 is a sectional view taken along line B-B of FIG. 8. The first unit U1 is a portion of the back-side seal forming portion 44 that is arranged on the back side. The first unit U1 includes a first support plate 52 that is arranged on the back side and forms a part of the support plate 51, and an additional elastic layer 62 that is laminated on the surface 52a of the first support plate 52 and forms a part of the heater elastic layer 61. The first support plate 52 is made of a metal plate material (for example, an aluminum plate material) having a predetermined thickness that extends in a strip shape along the left-right direction of the horizontal seal device 1. In the case of this embodiment, the thickness of the first support plate 52 is set to, for example, 1.5 mm. The surface 52a of the first support plate 52 is flat, and a plurality of additional elastic layers 62 are laminated on the surface 52a. Also, the back surface 52b of the first support plate 52 is flat. The additional elastic layer 62 is formed by laminating an elastic body having excellent heat resistance such as silicone rubber in layers. As shown in FIG. 8, the additional elastic layer 62 has a vertically long rectangular shape that extends along the short side direction of the first support plate 52 while having rounded corners in plan view. The additional elastic layers 62 are provided on the first support plate 52 so as to be arranged in a row while maintaining a space from each other in the longitudinal direction of the first support plate 52. In the case of this embodiment, the thickness of the additional elastic layer 62 is set to 1.5 mm. Note that the first support plate 51 is provided with through mounting holes 56 that are used when mounting the back-side seal forming portion 44 to the facing surface 42a of the heater block 42 using mounting means (for example, screws, etc.).

[0047] FIG. 10 is a front view of the second unit U2, and FIG. 11 is a cross-sectional view taken along line C-C of FIG. 10. The second unit U2 is a portion of the back-side seal forming portion 44 that is arranged on the front side. The second unit U2 includes a basic elastic layer 63 that is arranged on the front side and constitutes a part of the heater elastic layer 61, and a second support plate 53 that supports the basic elastic layer 63 and constitutes a part of the support plate 51. The second support plate 53 is made of a metal plate material (for example, an aluminum plate material) having a predetermined thickness that extends in a strip shape along the left-right direction of the horizontal seal device 1. The second support plate 53 is overlapped on the surface 52a side of the first support plate 52 and constitutes the support plate 51 together with the first support plate 52. In the case of this embodiment, the thickness of the second support 53 is set to be the same as the thickness of the additional elastic layer 62 (that is, 1.5 mm). Note that the thickness of the second support 53 is also set to be the same as the thickness of the first support. The surface 53a of the second support plate 53 is flat, and the basic elastic layer 63 is laminated on the surface 53a. Also, the back surface 53b of the second support plate 53 is flat and faces the surface 52a of the first support plate 52 when the second support plate 53 is overlapped on the first support plate 52. Note that the second support plate 53 is provided with a plurality of openings (accommodation portions) 54 that penetrate in the thickness direction. When the second support plate 53 is overlapped on the first support plate 52, the additional elastic layer 62 on the first support plate 52 is accommodated in each opening 54. The thickness of the second support plate 53 is set to be substantially the same as the thickness of the additional elastic layer 62.

[0048] Similar to the above-described additional elastic layer 62, the basic elastic layer 63 is formed by laminating an elastic body having excellent heat resistance such as silicone rubber in layers. The basic elastic layer 63 constitutes the heater elastic layer 61 together with the additional elastic layer 62. In the case of this embodiment, the thickness of the basic elastic layer 63 is set to 3.0 mm. As shown in FIG. 10, the basic elastic layer 63 has a contour corresponding to the shapes of the upper seal portion 33 and the lower seal portion 34 of the packaging bag P. The basic elastic layer 63 is formed on the surface 53a of the second support plate 53 so as to overlap the opening 54. Note that the surface 63a of the basic elastic layer 63 constitutes the surface 61a of the heater elastic layer 61.

[0049] The hardness of the basic elastic layer 63 and the additional elastic layer 62 that constitute the heater elastic layer 61 is not particularly limited as long as the object of the present invention is not impaired. For example, it is set to 50 degrees to 60 degrees. The hardness measurement method is carried out in accordance with JIS K6253-3:2012.

[0050] As shown in FIG. 10, among the surfaces 63a of the basic elastic layer 63, the portion surrounded by the region (contact region) S1 contacts the back surface f3b of the cylindrical film f3. Among the portions surrounded by such a region S1, in a plan view, the portion (first region S11) that overlaps the opening 54 contacts the portion (overlapping portion F3) where the main joining portion F2 and the cylindrical body F1 overlap among the back surface f3b of the cylindrical film f3. Further, among the portions surrounded by the region S1, the portion other than the first region S11 (second region S12) contacts only the cylindrical body F1 among the back surface f3b of the cylindrical film f3. As will be described later, when the cylindrical film f3 is sealed by being sandwiched between the back-side seal forming portion 44 and the front-side seal forming portion 45, the lower seal portion 34 for the packaging bag P arranged on the downstream side and the upper seal portion 33 for the packaging bag P on the upstream side connected thereto are formed simultaneously.

[0051] The basic elastic layer 63 and the second support plate 53 are respectively provided with through mounting holes 65 and mounting holes 55 that are used when mounting the back-side seal forming portion 44 on the opposing surface 42a of the heater block 42 using mounting means (for example, screws, etc.). The mounting holes 65 of the basic elastic layer 63 and the mounting holes 55 of the second support plate 53 are provided at positions that overlap the mounting holes 56 of the first support plate 52 when the second support plate 53 is overlapped on the first support plate 52.

[0052] FIG. 12 is a cross-sectional view of the back-side seal forming portion 44 along the longitudinal direction. As shown in FIG. 12, the back-side seal forming portion 44 is formed by overlapping the second unit U2 on the first unit U1. In the case of this embodiment, the thickness of the entire back-side seal forming portion 44 is set to 6 mm. The second unit U2 is overlapped on the first unit U1 such that the back surface 53b of the second support plate 53 contacts the front surface 52a of the first support plate 52. At that time, the additional elastic layer 62 formed on the first support plate 52 of the first unit U1 is fitted into the opening 54 formed in the second support plate 53. The additional elastic layer 62 is in a state of being overlapped with the basic elastic layer 63 formed on the second support plate 53 when housed in the opening 54. Therefore, in the heater elastic layer 61 composed of the basic elastic layer 63 and the additional elastic layer 62, the portion where the additional elastic layer 62 is overlapped has a greater thickness of the heater elastic layer 61 than the other portions. This portion with the increased thickness is particularly referred to as the step absorption portion 64.

[0053] FIG. 13 is an explanatory diagram showing the positional relationship between the surface 61a of the heater elastic layer 61 of the back seal forming portion 44 and the tubular film f3 when the horizontal sealing device 1 seals the tubular film f3. The upper side of FIG. 13 corresponds to the upper side (upstream side) of the packaging machine 10, and the lower side of FIG. 13 corresponds to the lower side (downstream side) of the packaging machine 10. As shown in FIG. 13, when the tubular film f3 moving from the upstream side to the downstream side is sandwiched and sealed by the back seal forming portion 44 and the front seal forming portion 45, the upper seal portion 33 is arranged on the lower side and the lower seal portion 34 is arranged on the upper side, and the packaging bag P is formed. And simultaneously with the lower seal portion 34 of the packaging bag P, the upper seal portion 34 is formed on the tubular film f3 connected to the upstream side of the packaging bag P. Thus, when the tubular film f3 is sandwiched between the back seal forming portion 44 and the front seal forming portion 45, the lower seal portion 34 of one packaging bag P on the downstream side and the upper seal portion 33 for the other packaging bag P are simultaneously formed on the tubular film f3 on the upstream side thereof. Note that the lower seal portion 34 of one packaging bag P and the upper seal portion 33 of the other packaging bag P are cut by the above-described cutter device 25 (see FIG. 1). At that time, the blank portion 37 connecting the lower seal portion 34 of one packaging bag P and the upper seal portion 33 of the other packaging bag P is removed.

[0054] FIG. 14 is a cross-sectional view schematically showing a state in which the tubular film f3 is sandwiched and sealed between the back seal forming portion 44 and the front seal forming portion 45. As shown in FIG. 14, when the tubular film f3 is sandwiched between the back seal forming portion 44 and the front seal forming portion 45, the back surface f3b contacts the surface 61a of the heater elastic layer 61, and the front surface f3a contacts the contact surface 47a of the contact portion 47. On the back surface f3b side of the tubular film f3, the aligning portion F2 that becomes the back sticking portion 35 of the packaging bag P is arranged. Therefore, on the back surface f3b side of the tubular film f3, due to the presence of the aligning portion F2, that portion is in a convexly raised state compared to the portion consisting only of the tubular body F1. The portion consisting only of the tubular body F1 has a thickness equivalent to that of two overlapping film materials F, namely the front film material F and the back film material F, while the portion where the aligning portion F2 overlaps the tubular body F1 has a state where four film materials F are overlapped.

[0055] In this embodiment, the surface (step absorption surface) 64a of the step absorption portion 64 of the heater elastic layer 61 is configured to contact the portion where the mating portion F2 overlaps the cylindrical body F1. Usually, the portion where the surface 64a of the step absorption portion 64 contacts the portion (overlap portion F3) where the mating portion F2 and the cylindrical body F1 overlap is set so that the overlap portion F3 of the mating portion F2 and the cylindrical body F1 can fit into the portion (first region S11) that overlaps the opening 54 that houses the additional elastic layer 62 of the step absorption portion 64.

[0056] When the cylindrical film f3 is sandwiched between the back side seal forming portion 44 and the front side seal forming portion 45 while the surface 64a of the step absorption portion 64 is in contact with the overlapping portion (overlap portion F3) of the mating portion F2 and the cylindrical body F1, among the heater elastic layer 61, the step absorption portion 64 is pushed by the mating portion F2 and is displaced more greatly in the thickness direction than the heater elastic layer 61 (basic elastic layer 63) of the portion that contacts only the cylindrical body F1, and a state is achieved as if the step absorption portion 64 has absorbed the mating portion F2. Therefore, not only the overlapping portion (overlap portion F3) of the mating portion F2 and the cylindrical body F1 but also the cylindrical body F1 adjacent thereto are in a form where the surface 61a of the heater elastic layer 61 is surely in contact. In this way, the cylindrical film f3 (packaging bag P) is uniformly sealed (heat welded) in the width direction.

[0057] After a predetermined portion of the cylindrical film f3 is sealed, the horizontal seal units 1A and 1B of the horizontal seal device 1 operate to move away from each other, and the sealed cylindrical film f3 (packaging bag P) is pulled downstream by a pulling device (not shown) arranged on the downstream side and thus supplied to the cutter device 25.

[0058] As described above, the horizontal seal device 1 included in the packaging machine 10 of this embodiment can manufacture a packaging bag with a back sticking portion 35 having an upper seal portion 33 and a lower seal portion 34 that are excellent in seal performance.

[0059] <Other Embodiments> The present invention is not limited to the embodiments described above and in the drawings. For example, the following embodiments are also included in the technical scope of the present invention.

[0060] (1) In the above Embodiment 1, the heater elastic layer was composed of two parts, namely the basic elastic layer and the additional elastic layer. However, the present invention is not limited to this. In other embodiments, the basic elastic layer and the additional elastic layer may be integrally formed.

[0061] (2) In the above Embodiment 1, the surface of the heater elastic layer of the back side seal forming portion was directly contacted with the back surface of the tubular film. However, as long as the object of the present invention is not impaired, other layers may be formed on the surface of the heater elastic layer. For example, when a printing layer using laser light or the like is formed on the surface of the film material, if the heater elastic layer directly contacts the tubular film made of such a film material, the peelability (release property) from the tubular film may decrease. In such a case, for the purpose of improving the peelability and the like from the tubular film, a thin release sheet made of a fluororesin or the like may be laminated on the surface of the heater elastic layer.

[0062] (3) The thickness of the step absorption portion may be appropriately set according to the type of the packaging bag (tubular film). Further, the thickness of the step absorption portion may be set to, for example, 1.2 times or more, preferably 1.5 times or more, more preferably 2 times or more, compared with the thickness of the basic elastic layer.

[0063] (4) When the upper seal portion and the lower seal portion of the packaging bag are processed with pattern-like uneven portions or the like for the purpose of improving design and opening properties, pattern-like uneven portions for forming such processing may be formed on the surface of the step absorption portion.

[0064] (5) As the heater elastic layer, for example, fluororubber or the like may be used in addition to silicone rubber.

[0065] As the support plate of the back side seal forming portion, in addition to the aluminum plate material, for example, other metal plate materials such as SS (Structural Steel) plate material may be used.

[0066] (7) In the above Embodiment 1, for the basic elastic layer and the additional elastic layer constituting the heater elastic layer (step absorption portion), the thickness of the basic elastic layer was set to be larger than the thickness of the additional elastic layer. However, the present invention is not limited to this. In other embodiments, the thickness of the basic elastic layer and the thickness of the additional elastic layer may be the same as each other, or the thickness of the basic elastic layer may be set to be smaller than the thickness of the additional elastic layer. From the viewpoints of sealing performance, durability, etc., it is preferable that the thickness of the basic elastic layer is set to be larger than the thickness of the additional elastic layer as in the above Embodiment 1.

Explanation of Reference Signs

[0067] 1…Horizontal sealing device, 1A, 1B…Horizontal sealing units, 10…Vertical multi-column filling and packaging machine (packaging machine), 11…Main body frame, 12…Film supply device, 20…Bag forming mechanism section, 21…Slitter device, 22…Former device, 23…Vertical sealing device, 24…Filling device, 25…Cutter device, 26…Guide body, 27…Discharge chute, 32…Accommodating section, 321…Accommodating main body section, 322…Narrow-width section, 33…Upper sealing section, 33a…Front of the upper sealing section, 33b…Back of the lower sealing section, 34…Lower sealing section, 34a…Front of the lower sealing section, 34b…Back of the lower sealing section, 35…Back sticking section, 36…Notch section, 37…Margin section, 42, 43…Heater blocks, 42a, 43a…Opposing surfaces of the heater blocks, 44…Back-side seal forming section, 45…Front-side seal forming section, 46…Support plate, 47…Contact section, 47a…Contact surface, 51…Support plate, 51a…Surface of the support plate, 52…First support plate, 52a…Surface of the first support plate, 52b…Back surface of the first support plate, 53…Second support plate, 53a…Surface of the second support plate, 53b…Back surface of the second support plate, 54…Opening (accommodating section), 55…Mounting hole, 56…Mounting hole, 61…Heater elastic layer, 61a…Surface of the heater elastic layer, 62…Additional elastic layer, 63…Basic elastic layer, 63a…Surface of the basic elastic layer, 64…Step absorption section, 64a…Surface of the step absorption section, 65…Mounting hole, Fr…Packaging material roll, F…Film material, F1…Cylindrical body, F2…Joining section, F3…Overlapping section, P…Packaging bag, S…Contents, S1…Contact area, S11…First area, S12…Second area, U1…First unit, U2…Second unit, f0…Original film roll, f2…Cut film, f3…Cylindrical film, f3a…Front of the cylindrical film, f3b…Back of the cylindrical film

Claims

1. A horizontal sealing device for heat-sealing the film materials on the front side and the back side that are overlapped with each other while sandwiching a tubular film having a joined portion where the side edges of the film materials are joined together, a back surface on which the joined portion is formed, and a front surface opposite to the back surface, comprising: a back-side seal forming portion that presses the back surface of the tubular film, and a front-side seal forming portion that presses the front surface of the tubular film; the back-side seal forming portion has a heater elastic layer that contacts the back surface of the tubular film and a support plate that supports the heater elastic layer; the surface of the heater elastic layer has a first region that contacts an overlapping portion formed by the overlapping of the joined portion and the tubular body in the back surface of the tubular film, and a second region that is adjacent to the first region and contacts the tubular body; the heater elastic layer includes a step absorption portion having a greater thickness than the heater elastic layer in the second region in the first region; the heater elastic layer includes a basic elastic layer having a predetermined thickness and an additional elastic layer having a predetermined thickness laminated on the support plate side of the basic elastic layer in the first region, and the step absorption portion is formed by the basic elastic layer and the additional elastic layer; the support plate includes a housing portion for housing the additional elastic layer, so that the surface of the basic elastic layer constitutes the surface of the flat heater elastic layer, a horizontal sealing device.

2. The horizontal sealing device according to claim 1, wherein the thickness of the additional elastic layer is equal to the depth of the housing portion.

3. The horizontal sealing device according to claim 1 or claim 2, wherein the thickness of the basic elastic layer is greater than the thickness of the additional elastic layer.

4. A horizontal sealing device for heat-sealing the film materials on the front side and the back side that are overlapped with each other while sandwiching a tubular film having a joined portion where the side edges of the film materials are joined together, a back surface on which the joined portion is formed, and a front surface opposite to the back surface, comprising: a back-side seal forming portion that presses the back surface of the tubular film, and a front-side seal forming portion that presses the front surface of the tubular film; the back-side seal forming portion has a heater elastic layer that contacts the back surface of the tubular film and a support plate that supports the heater elastic layer; The surface of the heater elastic layer has a first region that contacts an overlapping portion formed by the overlapping of the joining portion and the cylindrical body among the back surface of the cylindrical film, and a second region that is adjacent to the first region and contacts the cylindrical body. In the first region, the heater elastic layer includes a step absorption portion having a greater thickness than the heater elastic layer in the second region. The heater elastic layer includes a basic elastic layer having a predetermined thickness and an additional elastic layer having a predetermined thickness laminated on the basic elastic layer in the first region. The support plate includes a housing portion for housing the additional elastic layer. The backside seal forming portion A first unit having the additional elastic layer and a first support plate that supports the additional elastic layer and constitutes the support plate. A horizontal seal device including a second unit having the basic elastic layer, a second support plate that supports the basic elastic layer, constitutes the support plate together with the first support plate, and includes an opening for forming the housing portion, and the additional elastic layer is housed in the opening and is overlapped on the first support plate.

Images