JP4856793B2 - Heat seal roller for packaging - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat seal roller for packaging having a peripheral surface serving as a heat seal surface, for example, heat-sealing a web-shaped packaging material along its longitudinal direction to form a cylindrical packaging material. It is possible to improve the property.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a packaging machine for continuously producing a bag package, a horizontal bag making and packaging machine 60 as shown in FIG. 4 is known. Fig.4 (a) is a perspective view which shows an example of a horizontal type bag making filling packaging machine, The same (b) is a cross-sectional view of (a). The horizontal bag making and packaging machine 60 forms a web-shaped packaging material 63 into a cylindrical packaging material 65, and fills or feeds the product A, which is a package, into the cylindrical packaging material 65. This is a packaging machine capable of continuously manufacturing the bag package 72 containing the product A at a high speed by sealing 65 in front and behind the product A. The web-shaped packaging material 63 fed out from the film roll 61 by the guide roll 62 and the paper drawing roll 66 is formed into a curved shape while being run by a molding machine 64 such as a former. The packaging material molded in a curved shape is pulled and traveled by the packaging material feeding means 68 including a pair of paper drawing rollers 69 and 69 sandwiching the combined side edges 71 and 71. A pair of rotary heat seals that have a heated cylindrical sealing surface and are welded with both side edges 71, 71 of the curved web-shaped packaging material 63 sandwiched downstream of the packaging material feeding means 68. A vertical sealing means 70 comprising rollers 40, 40 is provided, and the web-shaped packaging material 63 is formed into a cylindrical packaging material 65 by the vertical sealing means 70.
[0003]
As shown in FIG. 5, in the conventional heat seal roller, the rotating shaft 42 rotates through bearings 43 and 44 arranged at a plurality of positions spaced apart in the axial direction on a support 41 fixed to the apparatus frame. A bevel gear 45 for transmitting power from an electric motor (not shown) is attached to the base end portion of the rotating shaft 42. A seal roller 47 is fixed to the tip of the rotating shaft 42 by a mounting bolt 46 screwed into the shaft end.
[0004]
The seal roller 47 includes an inner boss portion 48 that is fitted to the shaft end of the distal end portion of the rotating shaft 42, and an outer boss portion 49 that is integrally formed with the inner boss portion 48 via the top plate portion 51. In addition, a large number of grooves extending in the axial direction are formed on the outer peripheral surface 50 of the outer boss portion 49 so that the sealing surface can be noticed. An annular groove 52 having inner and outer boss portions 48 and 49 as peripheral walls is formed on the lower surface side of the seal roller 47, and a heater block 53 is fitted inside the annular groove 52. That is, the heater block 53 includes a head portion 54 in which the cast-in heater 57 is embedded, a mounting portion 55 fixed to the support body 41 as a fixing member by screws, and the head portion 54 and the mounting portion 55. It is composed of an intermediate portion 56 that is interposed therebetween and in which a thermocouple 58 for measuring the temperature of the seal roller 47 is embedded. In the heat seal roller 40 configured as described above, the cast heater 57 generates heat by supplying a current through the wire 59 to the resistance cast heater 57 embedded in the heater block 53, and the generated heat is generated from the heater block 53. The heat is transferred to the weight roller 47 and is used for heat sealing at the outer peripheral surface 50.
[0005]
However, in the heat seal roller 40, there is a slight gap g between the fixed heater block 53 and the rotation-side weight roller 47, and the heat generated in the heater block 53 is It is transmitted to the weighting roller 47 through the air interposed in the gap g. In general, since the heat transfer rate of air is low, the rate at which the heat generated in the heater block 53 is dissipated to portions other than the weight roller 47 is large, and heat energy is not effectively used. In addition, the heat conductivity from the heater block 53 to the weight roller 47 is not good, and the heat transfer to the weight roller 47 may be delayed or insufficient. Accordingly, when the packaging machine is started up, the time until the operating temperature of the weight roller 47 reaches the target is delayed, the work efficiency is lowered, or when the packaging material actually starts to be sealed, the weight from the weight roller 47 is increased. In some cases, the temperature of the weight roller 47 is greatly reduced and it takes time to recover the temperature, or the temperature becomes unstable and it is difficult to secure a steady state.
[0006]
Even if the temperature of the fabric weight roller 47 falls within a certain range, there is a considerably large temperature difference between the heater block 53 and the fabric weight roller 47. In general, the follow-up performance of the temperature rise of the weight roller 47 with respect to the temperature rise of the heater block 53 is also not good. Further, the temperature sensor composed of the thermocouple 58 measures the temperature of the heater block 53, and does not directly measure the temperature of the outer peripheral surface 50 that is the heat seal surface of the weight roller 47. The temperature of the weight roller 47 depends on indirect estimation from the temperature of the heater block 53 empirically. In addition, the temperature on the basis roller side 47 may change depending on the start and stop of the packaging operation or the packaging conditions such as the ambient temperature. This change is caused by the heater block 53 due to the presence of an air layer. It appears late as a temperature change at the sensor position where the thermocouple 58 is provided. Therefore, there is a gap between the estimated temperature of the weight roller 47 and the actual temperature, and the error is not necessarily constant and changes depending on the situation. Therefore, the actual temperature of the weight roller 47 is accurately estimated. It is difficult. As a result, the influence on the finish of the seal cannot be avoided, and it is conceivable that the sealing performance and appearance of the bag package are impaired.
[0007]
In addition, as a heat supply to the seal roller, a heater block having a heating wire as a heating element is fixed to the seal roller so as to rotate together with the seal roller, and the power supply to the rotating heating element is brushed It is also done through. The heat conduction between the heater block and the seal roller is performed directly by mechanical fixation, so the heat conductivity is good, but the cost of the brush is expensive as a part and wears down due to sliding Maintenance is indispensable.
As a heat seal roller that transmits heat generated in the fixed side heater block to the seal roller through the air interposed in the gap formed between the heater block and the rotation side seal roller, Japanese Patent Application Laid-Open No. HEI 11-11 There is one disclosed in Japanese Patent No. 348934.
[0008]
[Problems to be solved by the invention]
In the heat seal roller, the heat conduction between the heater block having the heating element and the seal roller is not efficient due to the presence of an air layer between the heater block and the weight roller. Based on the above knowledge, the present invention effectively solves the above problem by transferring heat between the heater block and the seal roller that rotate relative to each other through the contact state, thereby improving the heat conduction between them. An object is to devise the structure of the heat seal roller for packaging so that it can be done.
[0009]
An object of the present invention is to transfer heat through a contact state between a fixed heater block and a rotating seal roller, thereby improving heat conduction between the two and efficiently transferring heat to the seal roller. The temperature of the seal roller can be quickly followed according to the heat generation of the heater block, and the temperature change of the seal roller is quickly reflected in the detected temperature of the temperature sensor provided in the heater block. It is possible to improve the sealing performance of the bag packaging body and the appearance of the bag packaging body by performing the heat control of the heating element provided in the heater block with a little delay and good, and improving the seal finish. It is to provide a heat seal roller for packaging .
[0010]
[Means for Solving the Problems]
Packaging heat-sealing roller according to the present invention, a rotatable seal roller with said rotary shaft attached to chromatic and and the rotation axis of the sealing circumferential surface for sealing by welding the packaging materials, with respect to the fixed member A heater block provided in a non-rotatable manner and having a heating element therein and capable of conducting heat with the seal roller, wherein the heater block is a rotation axis of the seal roller with respect to the fixed member A direction parallel to the rotation axis of the seal roller with respect to the seal roller by a restoring force based on deformation of an elastic member disposed between the fixed member and the fixed member. The thrust washer is pressed through a thrust washer , and the thrust washer is provided with a conduction path for the heat conduction.
[0011]
According to the heat seal roller for packaging according to the present invention, the heater block is provided so as not to rotate with respect to the fixed member, and is heated by the heating element inside, and has a peripheral surface serving as a seal surface with the heater block. Heat transfer to and from the possible sealing rollers takes place through thrust washers that are mostly pressed in a direction parallel to the rotational axis of the sealing roller. Therefore, heat conduction therebetween for relative rotation, via the thrust washer is a sliding bearing, since the rapidly performed through extremely reduced while and contact resistance to relative rotation, heat conduction through the air Compared with a heat seal roller with a structure that relies entirely on the heat transfer, heat transfer is performed efficiently, and the thermal response between the heater block and the seal roller is improved, resulting in a temperature difference between the two. Becomes smaller.
[0012]
In the packaging heat seal roller, the heater block is supported slidably in a direction parallel to the rotation axis of the seal roller with respect to the fixed member, and the heater block is interposed between the fixed member and the heat block. It is pressed against the seal roller via the thrust washer by a restoring force based on the deformation of the arranged elastic member. By slidably supported in a direction parallel to the axis of rotation of the sealing rollers with respect to the fixed member heater block, a heater block for sealing roller, separable ready next to the direction along the rotational axis, the heater By placing the elastic member in a deformed state between the block and the fixed member, the heater block is pressed against the seal roller by using the restoring force generated in the elastic member, and the contact force between them is always constant. Good heat conduction takes place in contact. The elastic member can be, for example, a compression coil spring, but can also be a metal spring such as a disc spring or an elastic body made of resin such as rubber.
[0013]
In this packaging heat seal roller, the heating element of the heater block may be a cast-in heater that generates heat when power is supplied from a power source through a wire. The heating element of the heater block is a cast-in heater that is made of heating wire or the like and generates heat by being supplied with power from the outside, so that it is not necessary to use a brush that is expensive and requires maintenance, and can be supplied with low cost. The structure is obtained.
[0014]
Further, in the packaging heat seal roller, a temperature sensor can be attached to the heater block in the vicinity of the thrust washer . That is, since the member on the fixed side as close as possible to the seal roller is a thrust washer , the temperature sensor detects the temperature as close as possible to the temperature of the seal roller by placing the temperature sensor close to the thrust washer. Is done. Even when the actual temperature of the seal roller is estimated from the detected temperature, the estimation error is reduced.
[0015]
This packaging heat-sealing roller forms a cylindrical packaging material by applying vertical heat sealing to both side ends of a web-like heat-weldable packaging material that runs in the horizontal direction, and puts a product inside the cylindrical packaging material. Applying to the vertical heat seal roller that performs the vertical heat seal of the horizontal manufacturing bag filling and packaging machine that bags and packs the product by cross-sealing the cylindrical packaging material at a position where the product is sandwiched in front and back Can do. Since the peripheral surface of the heat seal roller is a heat seal surface, by sandwiching the both side ends of the web-like heat-weldable packaging material between a pair of rotating heat seal rollers, applying heat while applying pressure, The web-shaped packaging material is formed into a cylindrical packaging material by applying continuous heat sealing to both end portions thereof.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a heat seal roller for packaging according to the present invention (hereinafter abbreviated as “heat seal roller”) will be described with reference to the accompanying drawings. 1 is a longitudinal sectional view showing an embodiment of a heat seal roller according to the present invention, FIG. 2 is a top view of the heat seal roller shown in FIG. 1, and FIG. 3 is an enlarged view of a main part of the heat seal roller shown in FIG. It is an expanded sectional view shown.
[0017]
Referring to FIGS. 1 and 2, the heat seal roller 1 includes a rotatable seal roller 2 and a heater block 3 having a heating element inside and capable of conducting heat between the seal roller 2. . The seal roller 2 includes a boss 4 on the center side, a disk-shaped top plate 5 that extends integrally with the boss 4, and a skirt-like shape that is integrally formed on the outer peripheral edge of the top plate 5. It consists of a cylindrical part 6. The seal roller 2 can be rotated together with the rotating shaft 7 by being attached to the shaft end portion 8 of the rotating shaft 7 with a set screw 9 at the boss portion 4. The seal roller 2 is formed as a seal peripheral surface 10 for sealing the outer peripheral surface of the cylindrical portion 6 by welding a packaging material, and in cooperation with another heat seal roller 1 having the same structure, The web-shaped packaging material is formed into a cylindrical packaging material by sandwiching the both-side end portions of the web-shaped packaging material between 10 and applying heat and pressure to both end portions.
[0018]
The rotating shaft 7 is rotatably supported with respect to the fixed member 11 by two ball bearings 13 and 14 spaced in the direction of the rotating axis 12 (vertical axis in the illustrated example). A power transmission gear 16 is fixed to the other end portion (lower end portion in the illustrated example) 15 of the rotary shaft 7 by a key 17a and a set screw 17b. The fixing member 11 has a guide pin receiver 18 that extends upward, that is, in the direction of the heat block 3. A guide pin 19 that extends in a direction parallel to the rotation axis 12 is fixed to the guide pin receiver 18 by a set screw 20. Has been. It is preferable that at least three guide pins 19 are arranged at equal intervals around the rotation axis 12.
[0019]
An annular space 21 is formed on the lower side of the seal roller 2 between the boss portion 4 and the cylindrical portion 6, and the heat block 3 is loosely fitted in the annular space 21 to allow relative rotation of each other. Yes. In order to prevent blind rotation of the heat block 3 and to actively guide the heat block 3 along the direction parallel to the rotation axis 12, guide pins 19 fixed to the guide pin receiver 18 are formed on the heat block 3. The fitting hole 22 is fitted. The heat block 3 includes a first block portion 25 disposed on the outer side (lower side) of the annular space 21 and a second block portion 28 disposed on the inner side (upper side) of the annular space 21. The block portions 25 and 28 are fixed to each other by appropriate means. The first block portion 25 is provided with a cast-in heater 26 embedded in a state of extending annularly as a heating element. A thermocouple 29 as a temperature sensor is attached to the second block portion 28 with a set screw 30. The cast-in heater 26 is composed of a heating wire or the like that is directly powered by a wire 27 from a power source (not shown). Therefore, it is not necessary to use a brush that is expensive and requires maintenance, and can be supplied at low cost. can get.
[0020]
As shown in detail in the enlarged view of FIG. 3, a shallow annular groove 31 is formed in the second block portion 28 of the heater block 3 on the side facing the top plate portion 5 of the seal roller 2. A thin plate-like thrust washer 32 is disposed in the annular groove 31. On the other hand, the guide pin 19 is fitted in a loose fitting hole 33 that leaves a gap around the guide pin 19 in the first block portion 25, and is closely fitted in the fitting hole 22 in the second block portion 28. is doing. A coil spring 34 as an elastic member is disposed in the loose fitting hole 33 in a compressed state. The lower end of the coil spring 34 is in contact with the guide pin receiver 18 connected to the fixing member 11, and the upper end of the coil spring 34 is in contact with the lower surface of the second block portion 28. Accordingly, the second block portion 28 is pressed against the top plate portion 5 of the seal roller 2 from below by the restoring force of the coil spring 34 through the thrust washer 32. As described above, at least three guide pins 19 are arranged, and the coil spring 34 is also arranged for each guide pin 19, whereby the heater block 3 is urged toward the seal roller 2 with a good balance. Since the seal roller 2 is fixed to the shaft end portion 8 of the rotary shaft 7 by the set screw 9, even if the restoring force of the coil spring 34 acts on the top plate portion 5 via the thrust washer 32, the seal roller 2 There is no particular influence such as displacement in the direction of the rotation axis 12.
[0021]
According to the heat seal roller 1, the heater block 3 generates heat by energizing the cast-in heater 26 embedded therein, and is transmitted to the seal roller 2 through the thrust washer 32. That is, the thrust washer 32 is a heat conduction path between the seal roller 2 and the heater block 3. The heat transmitted to the seal roller 2 flows radially through the top plate part 5, reaches the skirt part 6, and is uniformly transmitted to the seal peripheral surface 10. The heat transfer between the rotatable seal roller 2 and the heater block 3 is performed in the region where the thrust washer 32 is pressed in a direction parallel to the rotation axis 12 of the seal roller 2. Since there is no air gap between 3 and 3, most of this is done quickly and efficiently through the thrust washer 32. Therefore, compared to a heat-sealing roller having a structure that relies entirely on heat conduction through air, a large amount of heat flows smoothly, and as a result, the temperature difference between the two becomes small and the thermal response is reduced. It is good.
[0022]
As an elastic member that pushes the heater block 3, a metal spring such as a disc spring or a resin elastic body such as rubber may be used instead of the coil spring 34. Further, in the heat seal roller 1, a thermocouple 29 can be attached to the heater block 3 in the vicinity of the thrust washer 32. The thermocouple 29 detects a temperature close to the temperature of the seal roller 2 by disposing the thermocouple 29 as a fixed member close to the thrust washer 32 as close as possible to the seal roller 2. Even when the actual temperature of the seal roller 2 is estimated based on the detected temperature, the estimation error is reduced, the thermal control accuracy of the seal roller 2 is improved, and the heat seal finish is also improved.
[0023]
【Effect of the invention】
Since the packaging heat seal roller according to the present invention is configured as described above, the following effects can be obtained. That is, this packaging heat seal roller conducts heat conduction between the fixed side heater block and the rotation side seal roller through a contact state using a thrust washer as a conduction path, thereby allowing heat conduction between the two via an air layer. It is possible to improve significantly compared to the case where it is performed. That is, the heat conduction between the relatively rotating heater block and the seal roller is a state where the resistance against the relative rotation is extremely reduced through the thrust washer which is a slide bearing, and the two are always in contact with each other by the urging force by the elastic member. Through quickly. The amount of heat generated in the heater block is transmitted to the sealing roller more smoothly and efficiently than when it is transferred through the air layer, so heat generation is not unstable and transmission delay is not increased. Can be effectively used for heat sealing without waste. In addition, since heat transfer between the two performed through the thrust washer is good, the temperature of the seal roller is higher than that of the heater block at the start of packaging when starting the heat seal roller. Thus, it can be made to follow quickly without a large delay. Furthermore, since the temperature difference between the heater block and the seal roller can be reduced, the temperature sensor provided in the heater block can quickly detect temperature changes such as the temperature drop of the seal roller that appears when the packaging material is actually sealed. The heat control of the heating element provided in the heater block can be quickly and satisfactorily performed to improve the seal finish and improve the sealing and appearance of the bag package. Further, since the temperature sensor can be disposed close to the thrust washer , the actual temperature of the seal roller can be estimated with high accuracy without causing a large error as in the conventional heat seal roller. Furthermore, the sealing roller can be manufactured at low cost and the frequency of maintenance can be reduced as compared with a heat sealing roller that is supplied with electric power using a brush.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a packaging heat seal roller according to the present invention.
FIG. 2 is a top view of the packaging heat seal roller shown in FIG.
FIG. 3 is an enlarged cross-sectional view showing an enlarged main part of the packaging heat seal roller shown in FIG. 1;
FIG. 4 is a diagram showing an example of a horizontal bag making filling and packaging machine.
FIG. 5 is a longitudinal sectional view showing an example of a conventional heat seal roller.
[Explanation of symbols]
1 packaging heat-sealed low La 2 sealing rollers 3 heater block 10 sealing circumferential surface 11 fixing member 12 sealing roller the rotational axis 26 a heating element (cast heater)
27 Wire 29 Temperature sensor (thermocouple)
32 Thrust washer 34 Elastic member (coil spring)
60 Horizontal production bag filling and packaging machine 63 Web-like heat-welding packaging material 65 Cylindrical packaging material 71 Both side edges 70 Vertical seal means A Product

Claims (4)

A seal roller rotatable with the rotary shaft seals the peripheral surface for sealing by welding the packaging material attached to the chromatic and and the rotation axis is provided unrotatably and inside with respect to the fixed member A heater block having a heating element and capable of conducting heat with the seal roller;
The heater block is slidably supported in a direction parallel to the rotation axis of the seal roller with respect to the fixed member, and is restored by a restoring force based on deformation of an elastic member disposed between the fixed block and the heater block . The sealing roller is pressed through a thrust washer in a direction parallel to the rotation axis of the sealing roller, and the thrust washer provides a conduction path for heat conduction . Heat seal roller. Before SL heating element packaging heat-sealing roller according to claim 1 which consists of a cast-in heater for heating is powered through the wires from the power source. The heat seal roller for packaging according to claim 1 or 2 , wherein a temperature sensor is attached to the heater block in the vicinity of the thrust washer . The packaging material is a web-like heat-weldable packaging material that runs in the lateral direction, and forms a tubular packaging material by applying longitudinal heat sealing to both end portions of the web-like heat-weldable packaging material. The vertical heat seal of the vertical production bag filling and packaging machine that bags and packs the product by feeding the product into the packaging material and horizontally sealing the cylindrical packaging material at a position where the product is sandwiched back and forth. The packaging heat seal roller according to any one of claims 1 to 3 , wherein the heat seal roller is applied to a heat seal roller.

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