JPH0780490B2 - Heat sealing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sealing device, and more particularly to a device capable of accurately heat-sealing a plastic film on a flange surface of a plastic container.

(Prior Art and its Problems) Conventionally, as a device for storing tofu in a plastic container and continuously heat-sealing the upper surface of the container with a plastic film having a printed pattern, as shown in FIGS.
Means 2 for sequentially conveying the plastic container 4 filled with the tofu 3, which is the content, to the seal portion, means for supplying the heat-sealing plastic film 6 to the seal portion, and the plastic film 6 at the seal portion for the flange portion of the container 4. A sealer 7 which moves up and down for heat sealing, a film pushing plate 9 which is provided on one side surface of the sealer 5 so as to be able to move up and down relatively to the sealer 7, and moves up and down together with the sealer 7, and the pushing plate. A heat-sealing device for a plastic container (hereinafter referred to as a conventional device), which includes an electromagnet 16 for vertically moving the 9 on and off relative to the sealer 7 and a cutter 8 for cutting the plastic film 6 after sealing, is provided. It is used.

In the above apparatus, a pattern 61 matching the size of the upper surface of the container is provided at the center of the plastic film 6, and a detection mark 62 indicating the unit length of the film 6 is provided at the side end of the film. An optical sensor 10 for detecting the stopped detection mark 62 is provided near the side end.

The signal from the sensor 10 is transmitted to the electromagnet 16 via the control unit 17.
Is turned on / off to move the push-in plate 9 up and down relative to the sealer 7, and the sensor 10 stops.
When 62 is detected, the electromagnet 16 is turned off and the lower end of the pushing plate 9 is located above the lower surface of the sealer 7, and the sealer 7 descends to perform heat sealing.

After heat sealing, the sealer 7 and the pushing plate 9 rise,
When the sensor 10 does not detect the stopped detection mark 62, the electromagnet 16 is turned on, the lower end of the pushing plate 9 is lowered below the lower surface of the sealer 7, and the film 6 is pushed below the horizontal surface of the film. To shift the film 6,
In this state, the sealer 7 descends to perform heat sealing.

After heat sealing, the sealer 7 and the pushing plate 9 rise,
While the lower ends of the sealer 7 and the push-in plate 9 are at the upper position, the next portion of the film 6 is supplied to the sealing portion and heat sealing is sequentially performed.

The relationship between the film 6 used in the above conventional apparatus and the container 4 is as shown in FIGS. 2 and 3. That is, as shown in FIG. 2, pictures 61 such as decorations and trademarks are continuously printed on the film 6 at equal intervals, and detection marks 62 are also provided on the side edges thereof at equal intervals. ing. The films 6 are arranged on the chain conveyor 2 in containers 4 (second
(Dashed line in the figure), the unit length of the film 6 is longer than the unit length of the arranged containers 4. As a result, the upper surface of the container 4 and the pattern 61 of the film 6 are different from those of the container 4a in FIG. The position (heat seal position) is the same,
A shift occurs in the leftward direction in the drawing, and at the position of the container 4f shown in FIG. 3, the pattern 61 and the upper surface of the container 4 do not match.

The unit length of the film 6 is longer than the unit length of the container 4 as described above in order to cope with a change in the size of the container 4 and a change in the space between the boxes 1 of the heat sealing device. is there.

The positional relationship between the pattern 61 of the film 6 at the heat seal position and the sensor 10 is such that 3 to 4 patterns 61 exist between the heat seal position and the sensor 10. This is because the pattern 61 of the film 6 and the upper surface of the container 4 do not have to be exactly aligned with each other at the time of heat sealing, and a slight degree of positional deviation can be tolerated. When adjusting the length of the film 6 at the time of heat sealing, since the unit length of the film 6 is usually an excessive length, there is no problem in the operation of the conventional device, but the sensor 10 and the sealer 7 are combined. The length of the film 6 is a factor (for example,
(When the tofu stored in the container 4 is raised, etc.)
When excessively consumed by the detection mark 62, the detection mark 62 may jump over the sensor 10.

In such a case, since the sensor 10 does not detect the stopped detection mark 62 until the next detection mark 62 reaches the position of the sensor 10, the electromagnet 16 remains in the ON state, In conjunction with the lowering of the sealer 7, the pushing plate 9 pushes the film 6 downward just before the heat sealing in each heat sealing process, and as a result, the displacement of the film 6 is maintained as it is or increases continuously. Since the electromagnet 16 is still in the ON state until the sensor 10 detects the next stopped detection mark 62, the pattern 61 and the container 4 do not coincide with each other, which causes a lot of defective products. . This point will be further detailed in the description of the operation of the device of the present invention.

Therefore, a first object of the present invention is to solve the above problems and provide a heat seal device in which no defective product is generated.

Further, in the above heat-sealing device, when the film 6 is heat-sealed on the upper surface of the container 4, the peelable resin sheet 11 such as Teflon as shown in FIGS. 1 and 6 is provided so that the sealer 7 and the film 6 do not stick to each other. Sealer 7, second support plate 13
It is arranged so as to surround b and the pushing plate 9.

The peelable resin sheet 11 includes a sealer 7 and a second support plate 13
The endless belt is formed so as to surround b and the push-in plate 9, and can be rotated in the left-hand winding direction as the film 6 advances to the right during heat sealing, so that it always comes into contact with the sealer 7 on a new surface. However, it is required to replace it with a new one on a regular basis because its peeling property deteriorates when it is used for a long time. Peelable sheet for replacement
Since 11 is an endless belt, it is necessary to remove various bolts and nuts holding the sealer 7 and to disassemble a part of the seal portion, which is very complicated.

Therefore, a second object of the present invention is to provide a heat seal device in which the endless belt-shaped peelable sheet 11 can be easily replaced.

(Means for Solving Problems) The above object is achieved by the present invention described below. That is, the first invention of the present invention, in the above-mentioned conventional device, the sensor is a sensor that can detect the stop of the detection mark and the jumping of the detection mark, and a timer is attached to the control unit, When the detection mark stops at the position of the sensor or jumps over the position of the sensor, the information turns off the electromagnet via the timer of the control unit and positions the lower end of the pushing plate above the lower surface of the sealer. The heat seal device is characterized in that the sealer descends in a state in which the film is not pushed in, and the film is heat-sealed to the flange surface of the container. Part
A first support plate connected to the drive source by a rod; a second support plate below the first support plate and elastically held with respect to the first support plate; The sealer is fixed to a second support plate, and the film pushing plate is provided on one side surface of the sealer. The second support plate has a first support bolt at one end thereof. Is vertically movably and horizontally rotatably supported by the second supporting plate and is vertically movably supported by the first supporting plate by the second supporting bolt at the other end. By rotating the second support plate with respect to the first support plate by the attachment / detachment mechanism provided in the support portion with the support bolt, one end of the second support plate is removed from the second support bolt. It is released and wrapped around the sealer, the second support plate and the film pushing plate. The heat-sealing device is characterized in that the separated endless belt-shaped peelable sheet can be removed and the peelable sheet can be replaced.

(Operation) According to the first aspect of the invention, the signal from the sensor 10 is transmitted to the power source of the electromagnet 16 via the control unit 17 provided with the timer to turn the electromagnet 16 on and off, and the push plate 9 By controlling the operation, when the detection mark 62 of the film 6 jumps over the sensor 10 for some reason, the signal indicating that the jump is reached (and the signal indicating that the detection mark 62 is detected) is controlled. By transmitting the power to the power source through the portion 17 to turn off the electromagnet 16, the pressing plate 9 immediately before the heat sealing is performed for each heat sealing.
Since the unit length of the film 6 is configured to be slightly longer than the unit length of the container 4, the pattern 61 of the film 6 is automatically set to the normal position with respect to the container 4 by preventing the operation of. Will be fixed.

According to the second aspect of the present invention, a support plate for the sealer 7 is provided.
By allowing one end of 13b to be opened with one touch, the endless belt-shaped peelable sheet 11 surrounding the sealer 7, the second support plate 13b and the pushing plate 9 can be easily replaced.

(Example) Next, the present invention will be described in more detail with reference to the preferred embodiments shown in the drawings.

FIG. 1 is a diagram for explaining the entire heat-sealing device of the present invention, and the details of the device of the present invention are as described in the claims, but the main part thereof is a tofu-like contents 3 Means for sequentially transporting the plastic container 4 filled with the resin to the seal portion, means for supplying the heat-sealing plastic film 6 to the seal portion, and vertical movement for heat-sealing the plastic film 6 on the flange portion of the container at the seal portion. A sealer 7, a film pusher plate 9 which is provided on one side surface of the sealer 5 so as to be vertically movable relative to the sealer 7 and moves up and down together with the sealer 7, and the pusher plate 9 is turned on and off. An electromagnet 16 that moves up and down relative to the sealer 7, a sensor 10 and a control unit 17 that control the on / off of the electromagnet 16, and a plastic after sealing. Consisting of cutter 8 which cuts the Ilm 6.

The transporting means for the container 4 comprises boxes 1a, 1b, 1c ... Arranged at predetermined intervals on the endless chain belt 2 and a power source 5 for driving these belts 2 at a constant pitch.

The box 1 is made of heat-resistant metal, such as casting,
A flange surface for heat sealing is formed around the upper surface. It is preferable that a peelable material such as Teflon is bonded to the flange surface. In the box body 1, a plastic container 4 containing a content 3 such as tofu is placed. Further, a switch (not shown) is provided on the bottom of the box body 1, and when the container 4 is inserted, the weight of the box 4 turns on the switch and the driving means 5 is activated, and the box body 1 advances one unit to the right in the figure. It is supposed to do.

The seal portion is located right above the box 1c (FIG. 1), and the first support plate 13a is fixed to the two rods 12 connected to the driving means 5 as shown in FIG. A second support plate 13b is supported on the support plate 13a so as to be vertically movable and horizontally rotatable by a first support bolt 19 at one end thereof, and vertically movable by a second support bolt 20 at the other end thereof. Further, inside the support bolts 19 and 20, four push rods 14 around which springs are wound are elastically downwardly propelled from the support plate 13b at regular intervals.

Of course, the push rod 14 is inserted through the support plate 13a, but is not fixed. As shown in the first drawing, the lower support plate 13b is provided with a heating body, that is, a sealer 7, and one side surface of the sealer 7 so as to be vertically movable relative to the sealer 7 and move vertically with the sealer 7. Film pushing plate 9
And an electromagnet 16 for moving the push-in plate 9 up and down relative to the sealer 7 by turning the power on and off, and surrounding the sealer 7, the second support plate 13b and the film push-in plate 9. An endless belt-shaped peelable sheet 11 is loosely wound around.

When the rod 12 moves up and down, the sealer 7, which is a heating body, and the film pushing plate 9 that is vertically movable relative to the sealer 7 on one side surface of the sealer 7 and that moves up and down together with the sealer 7 move up and down. However, the pressing and pressing time are controlled by the four push rods 14.

One end of the push-in plate 9 is pivotally supported by the sealer 7 and interlocks with the vertical movement of the sealer 7. A spring 15 is provided between the upper portion of the other end of the pushing plate 9 and the drive unit 5, and the pushing plate 9 is always pulled upward.
An electromagnet 16 is provided below this end, and the electromagnet 16 is turned on / off by a signal transmitted from the sensor 10 via the control unit 17.
The lower end of the push-in plate 9 moves up and down relative to the sealer 7 by the action of.

The sealer 7 has a downwardly facing shape (FIG. 1), and the rectangular lower surface has a flange surface of the box body 1, that is, the flange surface of the container 4, and the sealer 7 is lowered. , The lower surface of the sealer 7 presses the peelable sheet 11 downward, and the flange of the container 4 and the film 6 are heated and pressed between the flange surface of the box 1 and the flange surface of the box 1 to weld them and heat seal the container 4. . At this time, it is preferable to provide a peelable surface such as Teflon on the lower surface of the sealer 7.

Further, a cutter 8 is provided behind the sealer 7, and the cutter 8 moves up and down in association with the movement of the box 1 to move the container 4
It has a function of cutting the film 6 connected in between.

The heat-sealing film 6 supplied between the container 4 in the box 1 and the sealer 7 is a continuous film having substantially the same width as that of the container 4, and has a central portion as shown in FIG. Is continuously printed with a pattern 61 such as a decoration or a trademark, and a detection mark 62 indicating the unit length of the film 6 is provided on the side edge of the film 61. The side edge of the film 6 is a sensor. It is possible to detect when the sensor 10 passes the position 10 and the detection mark 62 provided on the film 6 stops at the position of the sensor, and when the sensor 10 jumps over the position of the sensor 10.

Next, the operation of this device will be described.

First, when the container 4a filled with tofu 3 is put into the box 1a,
Due to the weight of the container 4a, a switch (not shown) is turned on, the drive unit 5 is activated, and the container 4c stops immediately below the sealer 7 in about 1 second. At this time, the sealer 7 descends and the sealer 7
Peelable sheet between the lower surface of the box and the upper surface of the flange of the box body 1
11. The film 6 and the flange portion of the container 4 are heated and pressed to heat-seal the film 6 and the flange portion of the container 4. The heat sealing at this time is completed in a few seconds. At this time, the flange portion of the film 6 or the container 4 is not fused to the sealer 7 or the flange portion of the box 1 by the action of the peelable sheet 11.

Next, when a new container 4 containing tofu is set in the box body 1, heat sealing is performed by the same action. In this way, the film 6 and the container 4 are heat-sealed one after another, the cutter 8 is operated to cut the film 6, and the heat-sealed container 4 is taken out.

In the above operation, when the film 6 is overlapped with the containers 4 arranged on the chain conveyor 2 as already described, the unit length of the film 6 is arranged as shown in FIG.
As a result, the upper surface of the container 4 and the pattern 61 of the film 6 coincide with each other at the position 4a as shown in the third illustration, but a shift occurs in the leftward direction. Three
As shown in the figure, at the position of the container 4f, the pattern 61 and the upper surface of the container 4f do not match.

As a method of making the pattern 61 of the film 6 almost exactly match the upper surface of the container 4 in correspondence with such an excessive length of the film 6, as shown in the first, fourth, fifth and sixth drawings, a pushing plate is used. 9
Is provided on one side of the sealer 7 so as to interlock with the sealer 7 and move up and down relative to the sealer 7. For example, as shown in FIG. 4, the pattern 61 of the film 6 and the upper surface of the container 4 are misaligned. In this case, the push-in plate 9 provided on one side surface of the sealer 7 is lowered simultaneously with the lowering of the sealer 7 as shown in FIG. 5, and the lower end of the push-in plate 9 is relatively moved with respect to the sealer 7. The film 6 is displaced downward in the right direction in the drawing by descending below the lower surface and pushing the film 6 below the horizontal surface immediately before heat sealing.

At this time, a sensor provided near the side end of the film 6
When the detection mark 62 stopped at that position does not exist in the position 10, that is, when the sensor 10 does not detect the detection mark 62, a signal indicating that the detection mark 62 is not detected is transmitted via the control unit 17 to the electromagnet 16
The power is transmitted to the power source, the electromagnet 16 is turned on, the push-in plate 9 descends as the sealer 7 descends, and the lower end of the push-in plate 9 is below the lower surface of the sealer 7, that is, in the solid line position in FIG. The film 6 is moved down to the right in the figure by pushing the film 6 downward and the sensor 6 detects the detection mark 62 stopped at the position of the sensor 10 due to the displacement of the film 6 (that is, the film 6 is accurate). When the sensor 10 detects the stopped detection mark 62, the electromagnet 16 is turned off, and the pushing plate 9 is released from the electromagnet 16 so that the lower end of the pushing plate 9 reaches above the lower surface of the sealer 7. Ascending, the sealer 7 heat seals the film 6 on the flange portion of the container 4 in that state.

When adjusting the length of the film 6, there is usually no problem in the above operation, but the length of the film 6 between the sensor 10 and the sealer 7 may be some factor (for example, the tofu 3 stored in the container 4 rises). When the sensor 10 is excessively consumed, the detection mark 62 may jump over the position of the sensor 10 and the sensor 10 may not detect the detection mark 62.

The case where the film 6 is excessively consumed as described above will be described in more detail with reference to FIGS. 9 to 13.

Usually, the tofu container 4 is filled with the tofu 3 by hand, and the tofu portion raised from the flange surface with a knife or the like so that the filling surface is substantially flush with the flange surface of the container 4 or may be slightly swollen. It is scraped, but when it happens to be filled with an excessive amount of tofu in the container 4 (A) as exaggeratedly shown in FIG. 9 (when the operator forgets to scrape the excessive amount of tofu) Etc., the film 6 is pulled out more by the amount of the rise.

As shown in FIG. 10, when the unit length between the detection marks of the film 6 is 102 mm, while the unit width of one container 4 (or box 1) is 100 mm (these values are actually If the detection mark 62 jumps 5 mm to the right from the sensor 10 due to the rise of tofu in Fig. 9, as shown in Fig. 10, the next heat seal In this case, the next detection mark 1 jumps over the sensor 10 and the sensor
Since it is not detected by 10, the pushing plate 9 descends as the sealer 7 descends, and at this time, since the electromagnet 16 is in the on state, the lower end of the pushing plate 9 is relatively close to the sealer 7. Descend to the bottom of the bottom of.

If the pushing length by the pushing plate 9 is 2 mm,
The misalignment between the sensor 10 and the detection mark is
5mm + length of indent 2mm-excessive length of film 2mm]
= 5 mm, and after that, the condition of 5 mm shift for each heat seal continues and heat seal is performed, and defective products continue to occur.

Further, if the pushing length by the pushing plate 9 is 3 mm, the above formula becomes [the initial positional deviation 5 mm + the pushing length 3 mm-the excess length of the film 2 mm] = 6 mm, and the heat sealing is continued. As shown in FIGS. 11 to 13, the sensor 10 is provided for each heat seal.
Since the detection mark stopped at the position cannot be detected, the electromagnet 16 is also in the ON state in the same manner, so that the lower end of the pushing plate 9 maintains the state of being lowered below the lower surface of the sealer 7, and the sensor 10 The deviation (δ) from the detection mark increases by 1 mm for each heat seal.

Therefore, in the above example, the film 6 is displaced 1 mm to the right by one heat seal, so unless the heat seal is repeated about 100 times, the sensor 10 and the detection mark will not return to the normal state. During this period, a lot of defective products are generated.

The above problem is that when the position shift occurs, stop the device,
It can be solved by adjusting the position of the film 6 to the normal position,
Stopping the device leads to a decrease in productivity, and if the misregistration is delayed, a large amount of defective products will occur.

Further, the above-mentioned problem is that when the displacement between the sensor 10 and the detection mark occurs, the pushing depth of the pushing plate 9 is set to about one pitch of the film (a little less than about 102 mm), so that the film 6 Loss is only one pitch, but it is not easy to accurately detect the width of the first displacement and transmit it to the push-in plate. It is more difficult to change automatically, and the manufacturing cost of the device is unacceptable.

In the present invention, the sensor 10 has the detection mark 62
In addition to the case where it is stopped at the position (that is, the prior art), it is possible to detect that the detection mark 62 jumps over the position of the sensor 10, and a timer is provided in the control unit 17,
If the detection mark 62 jumps over the sensor 10 for any reason as described above, the timer of the control unit 17 operates,
During the next heat sealing, the electromagnet 16 is turned off and the lower end of the pushing plate 9 is positioned above the lower surface of the sealer 7 so that the film 6 is not pushed in during the heat sealing.

In this way, the lower end of the pushing plate 9 pushes the film 6 for each heat seal until the film 6 is displaced leftward in the drawing relative to the container 4 and the detection mark 62 stops at the position of the sensor 10. There is no state. That is, the spring 15
The electromagnet 16 is kept off during the time when the pusher plate 9 is lowered by the sealer 7, so that the lower end of the pusher plate 9 is held above the lower surface of the sealer 7.

In this way, when the lower end of the pushing plate 9 is positioned above the lower surface of the sealer 7 for each heat seal and the heat seal is performed once or plural times, the unit length of the film 6 becomes the container 4 as described above. Since it is slightly longer than the unit length of, the film 6 automatically returns relative to the container 4 by the amount that the pressing plate 9 does not press the film 6 for each heat seal. The pattern 61 approaches the normal position for the container 4. When this is performed once or a plurality of times, the detection mark 62 relatively returns to the position of the sensor 10, and as a result, the film 6 returns to the normal position (that is, the position shown in FIG. 5), and thereafter, the sensor 10 and the pushing plate 9 are pressed. The relationship between and operates normally as in the conventional device. After that, even if the detection mark 62 jumps over the sensor 10 for some reason in the same manner as described above, the correction action is similarly exerted.

Therefore, according to the apparatus of the present invention, even if the film 6 is displaced, the positional deviation is automatically eliminated without stopping the apparatus, and it is not necessary to stop the apparatus.

Next, a second embodiment of the present invention will be described with reference to the drawings.

As shown in the first drawing, a peelable sheet 11 loosely supported by three easily removable rollers 18 is wound around the sealer 7, the second support plate 13b and the pushing plate 9. This releasable sheet 11 is in the shape of an endless belt, and if its releasability deteriorates due to long-term use, it needs to be replaced with a new one.

The peelable sheet 11 passes between the two supporting plates 13a, 13b shown in FIG. 6 and the four holding rods 14 and passes through the lower end of the pushing plate 9, and the sealer 7, the second supporting plate 13b and the pushing Board 9
Is loosely enclosed (FIGS. 1 and 6).

In this case, as shown in FIG. 6, the second support plate 13b is held at one end thereof by the first support bolt 19 so as to be vertically movable and horizontally rotatable, and at the other end thereof is supported by the second support bolt 20 for the second support. It supports the plate 13b. The second support bolt 20 has a spring 24 wound around the second support bolt 20 as shown in FIG. The sleeve 24 is composed of a large diameter portion 22 and a small diameter portion 23, and the small diameter portion 23 is opened on one side provided on the second supporting plate 13b shown in FIG. 8 which is a sectional view taken along the line AA in FIG. It is sized so that it can fit into the hole 25, and the lower end 26 of the support bolt 20 can pass through the open passage 27 of the hole 25. In such a configuration, when the large diameter portion 22 of the sleeve 24 is held and lifted, the small diameter portion 23 and the hole 25 of the support plate 13b are disengaged from each other, and the eighth
The second support plate 13 to which the sealer 7 is fixed is rotated by rotating the support plate 13b to the position shown by the alternate long and short dash line as shown in the figure.
Since one side end of b is opened, the endless belt-shaped peelable sheet 11 surrounding the sealer 7, the support plate 13b and the pushing plate 9 can be easily removed and replaced with a new one.

After removing the old peelable sheet 11 and replacing it with a new one, hold the large-diameter portion 22 of the sleeve 24 in the same manner as described above.
, The support plate 13b is returned to the position shown by the solid line in FIG. 8, and when the sleeve 24 is released in this state, the small diameter portion 23 of the sleeve 24 has a hole 25.
And the second support plate 13b is firmly fixed.

With the above configuration, the peelable sheet 11 can be replaced with one touch.

(Effect) According to the present invention as described above, there is provided a heat seal device in which the number of defective heat seal products is small and the isolation sheet can be easily replaced. In the above, the heat sealing of the tofu container has been described as a representative example, but the application of the device of the present invention is not limited to the heat sealing of the tofu container,
It is also useful in other applications.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the outline of the apparatus of the present invention, FIGS. 2 and 3 are diagrams for explaining the relationship between a film and a container, and FIGS. 4 and 5 are diagrams for explaining a film length adjusting method. 6, FIG. 7, FIG. 7 and FIG. 8 are diagrams for explaining the structure of the seal portion, and FIGS. 9 to 13 are diagrams for explaining the operation of the conventional device and the device of the present invention. . 1: Box body, 2: Chain belt 3: Tofu, 4: Container 5: Drive part, 6: Film 7: Sealer, 8: Cutter 9: Push plate, 10: Sensor 11: Peelable sheet, 12: Rod 13: Support plate, 14: Push rod 15: Spring, 16: Electromagnet 17: Control part, 18: Roller 19: Support bolt, 20: Support bolt 21: Spring, 22: Large diameter part 23: Small diameter part, 24: Sleeve 25: Hole

Claims (2)

[Claims] 1. A means for sequentially transporting a plastic container filled with contents to a sealing portion, a means for supplying a heat-sealing plastic film to the sealing portion, and the sealing portion heat-sealing the plastic film to a flange portion of the container. A sealer that moves up and down for that purpose, a film pusher plate that is vertically movable relative to the sealer on one side of the sealer, and moves up and down together with the sealer, and the sealer is turned on and off by turning the power supply on and off. It consists of an electromagnet that moves up and down relative to each other, and a cutter that cuts the plastic film after sealing, a pattern matching the size of the upper surface of the container is provided in the center of the plastic film, and the side edges are further provided. A detection mark indicating the unit length of the film is provided, and a stop mark is provided near the edge of the film. An optical sensor that detects the detection mark is provided, and the signal from the sensor turns the electromagnet on and off via the control unit to move the pushing plate up and down relative to the sealer, and the detection mark when the sensor stops If it is detected, the sealer descends and heat seals with the electromagnet turned off and the lower end of the pushing plate positioned above the lower surface of the sealer.
When the sealer and pushing plate rise, and the sensor does not detect the stopped detection mark, the electromagnet turns on and the lower end of the pushing plate descends below the bottom surface of the sealer, pushing the film below the horizontal plane of the film. After shifting the film, the sealer descends and heat seals in this state.After heat sealing, the sealer and push plate rise, and while the sealer and push plate are in the upper position, the next part of the film is supplied to the seal part. In a heat-sealing device for a plastic container in which heat sealing is performed sequentially, the sensor is a sensor that can detect a stopped detection mark and jumping of the detection mark, and a timer is attached to the control unit, If the detection mark stops at the sensor position or jumps over the sensor position, The information turns off the electromagnet via the timer of the control unit, the lower end of the pushing plate is positioned above the lower surface of the sealer, the sealer descends without pushing the film, and the film heats to the flange surface of the container. A heat seal device characterized by being sealed. 2. A means for sequentially transporting a plastic container filled with contents to a sealing portion, a means for supplying a heat-sealing plastic film to the sealing portion, and the sealing portion heat-sealing the plastic film to the flange portion of the container. A sealer that moves up and down for that purpose, a film pusher plate that is vertically movable relative to the sealer on one side of the sealer, and moves up and down together with the sealer, and the sealer is turned on and off by turning the power supply on and off. It consists of an electromagnet that moves up and down relative to each other, and a cutter that cuts the plastic film after sealing, a pattern matching the size of the upper surface of the container is provided in the center of the plastic film, and the side edges are further provided. A detection mark indicating the unit length of the film is provided, and a stop mark is provided near the edge of the film. An optical sensor that detects the detection mark is provided, and the signal from the sensor turns the electromagnet on and off via the control unit to move the pushing plate up and down relative to the sealer, and the detection mark when the sensor stops If it is detected, the sealer descends and heat seals with the electromagnet turned off and the lower end of the pushing plate positioned above the lower surface of the sealer.
When the sealer and pushing plate rise, and the sensor does not detect the stopped detection mark, the electromagnet turns on and the lower end of the pushing plate descends below the bottom surface of the sealer, pushing the film below the horizontal plane of the film. After shifting the film, the sealer descends and heat seals in this state.After heat sealing, the sealer and push plate rise, and while the sealer and push plate are in the upper position, the next part of the film is supplied to the seal part. In a heat-sealing device for a plastic container in which heat sealing is sequentially performed, the sealing portion includes a first support plate connected to a drive source by a rod, and a first support plate below the first support plate and the first support plate. A second support plate elastically retained with respect to the support plate, the sealer fixed to the second support plate, and one side surface of the sealer. The second supporting plate is supported at one end thereof by the first supporting bolt so as to be vertically movable and horizontally rotatable, and the other end thereof. The second support bolt is vertically movably supported on the first support plate by the second support bolt, and the second support plate is attached to and detached from the second support bolt by the attachment / detachment mechanism. By rotating the plate with respect to the first support plate, one end of the second support plate is released from the second support bolt to surround the sealer, the second support plate and the film pushing plate. A heat-sealing device, wherein an endless belt-shaped peelable sheet wound around a sheet can be removed and the peelable sheet can be replaced.