JPS5823619Y2 - heat sealing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat sealing device that applies heat sealing in the width direction to a plastic film tube or the like having a constant width that is continuously transferred in one direction at equal intervals in the longitudinal direction.

As shown in a schematic diagram in FIG. 1, this type of conventional general heat sealing device has a hot plate 1 that moves up and down, and a conveyor belt 2 that circulates in one direction arranged above and below. A plastic film tube 3 having a constant width is conveyed intermittently between the hot plate 1 and the conveyor belt 2 at a constant pitch in synchronization with the vertical movement of the hot plate 1. When the hot plate 1 is sent, the hot plate 1 descends and presses the tube 3 onto the conveyor belt 2 with its tip, and applies a heat seal 4 in the width direction to the tube 3 as shown in FIG. is raised and the tube 3 is fed again by a fixed pitch, and the next heat seal 4 is performed by the hot plate 1 which is lowered again.Then, the above operation is repeated and continued to apply a second heat seal 4 in the width direction to the tube 3. As shown in the figure, this is done at equal intervals in the longitudinal direction.

However, in this heat sealing device, the plastic film tube 3 is fed intermittently, and there is a stoppage time.
This lowers the operating rate, and also tends to cause deviations in the accuracy of constant pitch feeding, making it difficult to heat seal 4 to tube 3.
4 It was easy to cause variations in the spacing dimensions.

The present invention improves the above-mentioned drawbacks of the conventional technology, enables continuous feeding of heat-sealed materials such as plastic film tubes, and improves the efficiency of heat-sealing.
It is also an attempt to provide a heat sealing device that can eliminate variations in the heat sealing interval dimension, and therefore, the feature is that the material to be heat sealed is continuously placed between the opposing circumferential surfaces of the two. A slit is formed in the circumferential surface of the rotary shield ram in the axial direction thereof, and a hot plate is inserted into the slit through a hot plate retraction mechanism. In the heat sealing device that is provided so as to be freely protrusive and retractable in the drum radial direction, the hot plate protruding and retracting mechanism includes a hot plate support part that supports the hot plate within the rotating shield drum, and a hot plate support part that is provided at both ends of the support part so as to extend and retract from both sides of the rotary shield drum. a hot plate support that is slidably supported in the radial direction on the wall and has a roller support shaft that projects outward from the side wall and rotates together with the shield drum; It consists of a fixed cam that is inserted through the fixed cam with restricted rotation around its axis and has a recess and a protrusion on its periphery; and a cam roller that is provided on the protruding end of the roller support shaft and rolls on the periphery of the fixed cam.

Below, embodiments of the present invention will be described based on the drawings.
The figure is an overall view showing one example of the proposed device, and 3 is a rolled plastic film tube (original film).
, 5 and 6 are rotating shield drums and driven endless belts arranged vertically opposite to each other, 7 and 8 are a pair of upper and lower presser rolls and a pull-out roll, 9 is a guard motor that drives the pull-out roll 8, and the plastic film The manufactured tube 3 is pulled out between a pull-out roll 8 and a presser roll 7, and further passed through a guide roll 10 between a rotary shield drum 5 and a driven endless belt 6.

The rotary shield drum 5 has a drum shaft 11.1 projecting on both sides thereof, as shown in detail in FIGS. 4 and 5.
2 is rotatably supported on a frame 13 with bearings 14 and 15, and is pulled out by the pull-out roll 8 by interlocking the gear 16 fixed on one shaft 11 and the geared motor 9, or by another power source. Rotation in the A direction is applied in accordance with the speed at which the plastic film tube 3 is pulled out.

A rubber lining 17 is provided on the circumferential surface of the shield drum 5, and the circumferential surface has a pair of slits that are elongated in the axial direction and are directly opposed to each other.
18.19 are open.

A hot plate 20.21 is inserted into each of the slits 18.19 of the shield drum 5, and both hot plates 20.21 are mounted on the same hot plate support 22 inside the drum 5 with a pin 23 and a compression coil spring 24. Ammunition supported.

Roller spindles 25 are provided at both ends of the hot plate support part 22a that supports one hot plate 20 on the hot plate support stand 22, and at both ends of the hot plate support part 22b that supports the other hot plate 21. 26 is formed, and each roller support shaft 25, 26 projects outward from a square hole 29, 30 that is opened long in the radial direction in both side walls 27, 28 of the shield drum 5, respectively.

A cam roller 31. is attached to each protruding end of the roller support shaft 25.26.
32, and the cam rollers 31 and 32 are brought into rolling contact with respective peripheral edges of fixed cams 34 and 35 located outside on both sides of the shield ram 5.

The fixed cams 34 , 35 have protrusions 36 and recesses 37 facing each other on their peripheries, and are inserted through needle bearings 38 on each shaft 11 , 12 on both sides of the drum 5 , and on the frame 13 . bracket) is fixed at 39.40.

A hot plate retracting mechanism is constructed using the hot plate support base 22, fixed cams 34, 35, and cam rollers 31, 32 as main members.

Therefore, when the shield drum 5 rotates in the direction A, the cam rollers 31, 32 and 3132 on both sides of the drum 5 roll on the peripheral edges of the fixed cams 34 and 35, respectively, and the protrusions 36, 36 of the fixed cams 34, 35 rotate. At the same time, one of the cam rollers 31 and 31 on the same axis rides on the fixed cam 3.
The other cam roller 32.32 on the same axis falls into both the recesses 37.37 of 4.35, and the hot plate support 2
2 as a whole moves slightly in the diametrical direction inside the shield drum 5 by slidingly guided roller support shafts 25 and 26 into the square holes 29 and 30, and as a result of this movement, the tip of one of the hot plates 20 is moved from inside the slit 18. The tip of the other hot plate 21 protrudes outward, and conversely, the tip of the other hot plate 21 sinks further inward from the inside of the slit 19.

That is, within a certain rotational angle range of the shield drum 5, both the hot plates 20, 21 are arranged to alternately move in and out of the slots (18, 19) on the circumferential surface of the drum 5 via the cams 34, 35.

The hot plate 20.21 is formed to be elongated in the axial direction of the shield drum in accordance with the shape of the above-mentioned slit 18.19, and this length is set to be longer than the width dimension of the plastic film tube 3. The cross-sectional shape of the hot plate 20, 21 has a chevron-shaped tip as shown in FIG.

A conductive wire 43 led out from the hot plate 20, 21 is passed through the inside of a hollow shaft 11 on one side of the shield drum 5 and connected to a slip ring 44 fixed to the end of the shaft 11.

The driven endless belt 6 is the first. Second. Third. 4th pulley 45
．． 46, 47, and 48, and between the first pulley 45 and the second pulley 46, the hook is pressed along substantially the lower half of the circumference of the shield ram 5.

This driven endless belt 6 circulates in the B direction while being in contact with the lower surface of the plastic film tube 3 transferred as the shield drum 5 rotates in the A direction.

When the shield drum 5 rotates in the A direction and one of the hot plates 20.21 moves to a position close to the first pulley 45 of the driven endless belt 6, the hot plate 20 or 21 moves toward the cam 34.35. It is set so that it protrudes from the slit 18 or 19 of the drum 5, and when the drum 5 rotates approximately 30°A direction from that position, it returns to its original position within the slit 18 or 19.

As in the above embodiment, when the two hot plates 20 and 21 are provided on a part of the peripheral surface of the rotating shield drum 5 so as to be able to be taken in and out alternately, the plastic film tube 3 is attached to the shield drum 5. Even when the tube 3 is passed continuously between the driven endless belts 6, the heat seals 4 in the width direction can be continuously applied to the tube 3 at equal intervals in the longitudinal direction by the tips of the hot plates 20 and 21 that protrude alternately. Furthermore, even if the tube 3 is pressed down by the protruding tip of the hot plate 20 or 21, its lower surface is supported by the driven endless belt 6.
A stable and uniform heat seal 4 is added and the belt 6
Since it rotates together with the tube 3, there will be no adverse effects such as scratches on the tube 3.

Note that if the time required for protruding the hot plate 20 or 21 is too long, the tube 3 may be burnt out, so the time is preferably set within the range of the rotation angle of the shield drum 5 of 30 degrees as described above.

The diameter of the shield drum 5 may be made small and the number of hot plates may be one, or on the contrary, the diameter of the shield drum 5 may be made large and two or more heat plates arranged at equal angles will have the same effect.

In the illustrated example of FIG. 3, the heat sealing device is provided with a trifold device 49 and a perforation cutter device 50, and the trifold device 49 uses the heat sealing device to heat seal the
In order to reduce the width of the plastic film tube 3, the plastic film tube 3 is folded into three pieces (a preferred specific device for this is the one described in Japanese Patent Publication No. 52-47392).

stomach). The perforation cutter device 50 includes a comb roll 51,
Cutter rolls 52 having chevron-shaped sharp blades arranged dotted in the axial direction on a part of the circumferential surface are arranged above and below, and these rolls 5
1. By passing the plastic film tube 3 between
are engraved side by side on the heat seal 4.

The plastic film tube 3 heat-sealed 4 and having perforations 53 is used as a bale bag such as a large garbage bag.

FIG. 8 shows another embodiment of the heat sealing device according to the present invention.
In place of the endless driven belt 6, a driven drum 54 having a rubber layer formed on its surface is used.

The device of the present invention can also be used for heat-sealing materials other than the plastic film tube 3 described above.

As described above, in the present invention, a heating plate is provided in the axial direction on a part of the circumferential surface of the rotating shield drum, and a constant width is provided between the shield drum and the driven endless belt or driven drum disposed opposite thereto. Since heat sealing can be applied to the workpiece in the width direction while continuously transporting the heat-sealed workpiece, the operating rate can be significantly increased compared to the conventional heat-sealing process using intermittent feeding. , according to the heat-sealed material that is continuously transferred and the hot plate on the continuously rotating shield drum,
This method has the advantage that there is no deviation in the interval size between the heat seals, which occurs with conventional intermittent feeding, and it is possible to perform continuous sealing with equal intervals at all times.

Furthermore, in the present invention, the hot plate is provided in the slit on the circumferential surface of the rotating shield drum via a hot plate moving mechanism so that it can freely move in and out in the radial direction of the drum, so the rotating shield drum and the driven endless belt can be used in combination. In this case, excessive heating of the heat-sealed workpiece is prevented, and heat sealing can be performed without burning out the workpiece, and the hot plate retraction mechanism supports the hot plate within the rotating shield drum. A hot plate that rotates together with the shield drum and has a hot plate support part and a roller support shaft that is provided at both ends of the support part and is slidably supported in a radial direction on both side walls of the shield drum and projects outward from the side walls. a support stand, a fixed cam that is inserted onto a drum shaft protruding from both side walls of the sealed drum and whose rotation about the shaft is restricted and has a recess and a protrusion on its peripheral edge; Since it is cut from a cam roller that rolls on the periphery, the hot plate moves in and out automatically and accurately as the seal drum rotates, and the heat-sealed material is prevented from burning due to overheating of the hot plate. Cutting can be reliably prevented, and since the rotation of the shield drum is used to move the hot plate support in the radial direction of the drum via a cam mechanism, it can also be used as the drive source for the shield drum, simplifying the entire device. This has great advantages.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional example, Fig. 2 is a plan view of the negative part of a heat-sealed material subjected to heat sealing, Fig. 3 is an overall view showing an example of the proposed device, and Fig. 4 is the same device. Fig. 5 is a side view of the drum, Fig. 6 is a cross-sectional view of the hot plate, and Fig. 7 is a cross-sectional view of the heat-sealed material subjected to heat sealing and perforations. FIG. 8, which is a partial plan view, is a schematic view showing the other side of the present device. 3...Plastic film tube (heat sealed material), 5...Rotating shield drum, 6
......Followed endless belt, 54...Followed drum, 20, 21...Hot plate, 4...Heat seal, 18.19...・Slit, 22...
...Hot plate support stand, 25, 26...Roller spindle, 34, 35...Fixed cam, 31.32...
...Camrolla.

Claims (1)

[Scope of utility model registration request] A rotary shield drum through which a heat-sealed material is passed continuously between the opposing circumferential surfaces of the two, and a driven endless belt or driven drum, and a slit is formed in the circumferential surface of the rotary shield drum in the axial direction thereof. In the heat sealing device, a hot plate is provided in the slit so as to be freely protrusive and retractable in the radial direction of the drum via a hot plate retractable mechanism, and the hot plate retractable mechanism is a heat plate that supports the hot plate within the rotary shield drum. a plate support, and a hot plate support that is provided at both ends of the support and is slidably supported in the radial direction on both side walls of the rotating shield drum, has a roller support shaft that projects outward from the side wall, and rotates together with the shield drum. a fixed cam that is inserted onto a drum shaft protruding from both side walls of the rotary shield drum and has a recess and a protrusion on its periphery; A heat sealing device comprising: a cam roller that rolls on the periphery of a fixed cam;