JPH0469873B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a heat seal roll for mutually heat sealing resin layers of film materials, sheet materials, etc. each having at least one resin layer. Proper heat sealing is extremely easy to achieve, and heat seal rolls,
As a result, the durability of the heat seal blade is improved.

(Prior Art) Heat sealing of resin layers of film materials, such as sheet materials, is currently widely performed for various purposes, and many types of heat seal rolls for this purpose have also been proposed.

FIG. 6 is a schematic side view illustrating a known heat seal roll that is applied to automatic filling machines for liquids or viscous substances among various types of heat seal rolls, and 1 in the figure shows the state where the slitter process has been completed. 2 and 3 are the winding rolls of film material, respectively.
A guide roll for film material being unwound from a take-up roll 1 is shown.

Here, a film material unwound from the take-up roll 1, for example, a laminated plastic film 4.
After passing through guide rolls 2 and 3, the film is folded in half in the width direction by a film folding fitting 5, and then sequentially transferred to a vertical sealing roll 6 and a horizontal sealing roll 7, which also serve as pull-out rolls for the laminated plastic film 4. be passed.

Here, the vertical seal roll 6 includes a pair of roll body portions 6a that are arranged close to each other in parallel and rotated in mutually opposite directions;
The vertical sealing roll 6 is equipped with a heater built into the roll body portion 6a and a flange-shaped heat sealing blade 6b extending in the circumferential direction of the roll body portion 6a. It functions to heat-seal the free ends of the plastic film 4 in the width direction in the longitudinal direction, as shown by diagonal lines in the figure.

Further, the horizontal seal roll 7 is arranged in the same way as the two roll body parts 6a, and also includes a pair of roll body parts 7a that are rotationally driven, a heater built into each roll body part 7a, and a roll. The main body portion 7a is provided with a heat seal blade 7b extending in the length direction and forming an arc shape in the circumferential direction, and the laminated plastic material 4 is sealed at a predetermined interval in the length direction by this horizontal seal roll 7. This is also heat-sealed in the horizontal direction as shown by diagonal lines in the figure.

The liquid or viscous substance is filled into the plastic film 4, which is sequentially heat-sealed in the vertical and horizontal directions, through the nozzle 8, to the inside of the plastic film 4 after the vertical sealing is completed. After completing such filling and lateral sealing, the plastic film 4 is removed from the middle of the lateral sealing portion 10 by a cutter roll 9 disposed below the lateral sealing roll 7. , often cut into individual bags.

In such an automatic filling machine, heat sealing by the vertical sealing rolls 6 is achieved by using a flange-shaped flange-shaped body integrally provided on each roll main body portion 6a of the pair, as shown in the vertical cross-sectional view in FIG. 7a. By sandwiching the free end of the plastic film 4 in the width direction between the heat sealing blades 6b and pressurizing and heating the plastic film 4, heat sealing by the horizontal sealing roll 7 is performed as shown in FIG. 7b.
As shown in the figure, the plastic film 4 is sandwiched between both heat sealing blades 7b which are integral with the roll body portion 7a and arc shaped in the circumferential direction.
This is carried out by applying pressure and heating to melt the plastic film 4 while expelling the liquid or viscous substance present inside the plastic film 4 upward or downward, and then hardening it.

By the way, the heat sealing blades 6b, 7b of both the heat sealing rolls 6, 7 here
As shown in the perspective view in FIG. 8, the clearance adjustment is carried out by rotatably supporting one of the roll body parts 6a, 7a of each pair at a predetermined position, and then rotating the other roll body part 6a, 7a. , within each guide frame 11, 12, with bearing members 13, 14 supporting both ends thereof, each guide frame 11 is allowed to move forward and backward relative to one roll main body portion 6a, 7a. , 12 and abut against the respective bearing members 13, 14, by manually rotating the asiast bolts 15, 16, which are screwed into the bearing members 13, 14 for the other roll main body portions 6a, 7a. against or in accordance with the spring force of a spring interposed between each pair of rolls, one of the roll body portions 6
This is done by displacing it with respect to a and 7a.

(Problem to be Solved by the Invention) However, in the case of the conventional heat sealing rolls 6 and 7, the clearance adjustment of the respective heat sealing blades 6b and 7b is performed by relying on the intuition of the operator. This is done by manually operating the bolts 15 and 16, and for the plastic film 4, which has a thickness of several tens of microns in most cases, the clearance can be adjusted by a few microns to more than ten microns by manual operation. Since it was extremely difficult to perform this with sufficient accuracy, there was a problem in that there was an extremely high possibility that sealing defects would occur in the vertical and horizontal sealing portions of the respective heat sealing rolls 6 and 7.

To explain this using the horizontal seal portion as an example, if the clearance between the paired roll body portions 7a is too large and the pressing force against the plastic film 4 is insufficient, the As shown in the enlarged cross-sectional view, in the seal portion 17,
A liquid pool 19 caused by not being able to sufficiently squeeze out the liquid 18 as a packaged object upward or downward.
In addition, a parting line 20 due to insufficient melting of the resin layer remains on the joint surface of the plastic film 4, resulting in a significant reduction in seal strength.

On one side, the paired roll main body portion 7
If the clearance a is too small, as shown in the enlarged cross-sectional view in FIG. The sealing portion 17 is pushed out from the plastic film 4 toward the rear in the direction of movement.
Furthermore, since there is almost no resin that contributes to adhesion of the plastic film 4, the sealing strength is significantly reduced and the molten resin may be mixed into the packaged item.

In addition, such conventional heat sealing rolls 6, 7, especially their heat sealing blades 6
Both b and 7b are structural carbon steel materials, mostly
Since it is made of S55C and the surface hardness cannot be made very high, there is a problem that the heat sealing blades 6b and 7b will wear out relatively early due to repeated heat sealing. When the packaged item is wasabi or other natural food or contains natural food, when some sand or other hard substances attached to or contained in the natural food get caught between the heat seal blades. This was particularly important.

Therefore, in this prior art, in order to continue proper heat sealing, the heat sealing blades 6b, 7
It is necessary to frequently perform the troublesome clearance adjustment of step b, and especially when large irregularities occur on the surface of the heat sealing blade 7b due to sand or other hard substances getting caught,
Even with such clearance adjustment, it was virtually impossible to maintain sufficiently proper heat sealing.

The present invention advantageously solves the problem of the prior art, and eliminates the need for clearance adjustment of each heat seal blade that relies on the operator's intuition, thereby making it extremely easy to prevent seal failures. We have created a heat seal roll that not only reliably prevents damage but also effectively prevents damage to the heat seal blade, allowing proper heat sealing to be continued for a long period of time without the need to adjust the clearance of the heat seal blade. This is what we provide.

(Means for Solving the Problems) The heat seal roll of the present invention is particularly provided with circular position regulating flanges that are in contact with each other at at least two locations on each pair of roll main body portions, for example, at both ends and on the circumferential surface. At least one heat-sealing blade extending in the length direction or the circumferential direction of each pair of roll main body portions is placed radially inward from the circumferential surface of the position regulating flange, for example, from several tens of microns to several tens of microns. The surface portion of the sheet seal blade that extends at least in the length direction of the roll main body portion is formed of tool steel.

(Function) In this heat seal roll, by specifying the proximity position of the pair of roll body parts by the abutment of each position regulating flange, the position between the heat seal blades of each roll body part is specified. , under the action of a heat-sealing blade pre-positioned radially inward from the circumferential surface of the position regulating flange,
Since it is possible to ensure the desired clearance depending on the thickness of the heat sealing material, its base material, and the resin layer that contributes to heat welding, it is possible to secure the desired clearance between the pair of rolls of the heat sealing material. The heat-sealing blade can always properly pressurize the heat-sealing material as it passes through, and therefore, seal failures due to under- or over-pressurization can be almost completely prevented. .

Here, since anyone can easily bring the position regulating flanges of each roll into contact with each other by means of screw means, cylinders, or other actions, regardless of skill, both heat seal blades can be brought into contact with each other. This results in an advantageous reduction in the number of man-hours required for clearance adjustment.

Furthermore, by forming at least the surface portion of the heat-sealing blade of the horizontal seal roll with tool steel, for example, high-speed steel, the surface hardness of the heat-sealing blade can be significantly increased. Not only is normal wear and tear on the heat seal blade surface almost completely prevented, but even if sand or other hard substances get caught between the heat seal blades, no damage to the heat seal blade surface will occur. The occurrence of heat sealing is sufficiently prevented, and proper heat sealing can therefore be continued for a long period of time without the need for adjusting the clearance of the heat sealing blade.

Here, the tool steel on the surface of the heat-sealing blade can be attached to the main body of the heat-sealing blade by brazing or other methods.

In addition, here, if the heat seal blade main body part of the heat seal roll, and sometimes the position regulating flange, are also configured separately from the roll main body part, and if they are assembled afterwards,
The number of man-hours required for manufacturing the heat-sealing roll can be effectively reduced, and this is particularly noticeable when the heat-sealing blade of the horizontal sealing roll is constructed separately. In addition, this makes it possible to reduce the amount of material removed and sufficiently prevent a decrease in material yield, and it also becomes possible to replace only the worn heat seal blade.
Note that each heat-sealing blade can be attached to the roll body using brazing, screwing, or other known methods. It is preferable to perform polishing, grinding, etc.

(Example) Examples of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, 31 is a horizontal seal roll, 32 and 33 are
A pair of roll main body portions constituting the horizontal seal roll 31 are shown, and here the respective roll main body portions 32 and 33 arranged parallel to each other are shown.
are equipped with a heater (not shown) inside them,
These are also rotationally driven in mutually opposite directions by a drive means (not shown).

Here, at least two locations in the axial direction of each of the pair of roll body portions 32, 33, at both ends in the figure, are preferably configured separately from the roll body portions 32, 33. Position regulating flanges 34, 35 each having a circular contour with the same diameter are provided, and opposing peripheral surfaces 34a, 3 of these position regulating flanges 34, 35 are provided.
5a can be brought into contact with each other, and a heat seal is provided on each roll body portion 32, 33, extending in the length direction between the respective position regulating flanges 34, 35 and forming an arc shape in the circumferential direction. Blade 3
6 and 37, respectively, and each of these heat seal blades 36 and 37, as well as the circumferential surface thereof, is
As is clear from the cross-sectional view shown in FIG. b, the position regulating flanges 34 and 35 are located somewhat radially inward from the circumferential surfaces 34a and 35a of each of the position regulating flanges 34 and 35, respectively.

Here, each heat seal blade 36, 37
is a heat sealing blade body portion 3 projecting radially outward from each roll body portion 32, 33;
6a, 37a, and surface portions 36b, 37b made of tool steel, which are fixed by brazing or otherwise to the outer circumferential surfaces of these body portions 36a, 37a, which may be made of carbon steel, for example.

These surface portions 36b, 37b can be made of carbon tool steel, high speed tool steel, or alloy tool steel having a thickness of about 2 mm, among others, SKH4A or high speed tool steel.
It is preferable to use a material of the order of SKH4B.

Such heat-sealing blades 36 and 37 have a surface portion 36 that has been hardened in advance, for example, vacuum hardened.
b, 37b to heat seal blade main body portions 36a, 3
7a, preferably after which the respective surface portions 36
b, 37b are ground or polished.

In the example shown here, the outer peripheral surfaces of the heat-sealing blade main body portions 36a, 37a are also arcuate, but they may also be flat surfaces.

When manufacturing the horizontal seal roll 31 as described above, each heat seal blade main body portion 36a,
37a can be integrally molded with the roll body parts 32, 33, but if each of them is constructed separately, the roll body parts 32, 3 of the respective heat seal blades 36, 37
3 is attached to each of the roll body parts 32 and 33, which are machined into an arc shape, with a plurality of grooves, three grooves each in the figure, extending in the axial direction and positioned at a predetermined interval in the circumferential direction. While providing grooves 32a and 33a, respectively, heat seal blades 36 and 37 made of angular bodies whose outer circumferential surfaces have been formed into arcuate shapes or not are fitted into the respective grooves 32a and 33a, A heat-sealing blade 36 fixed in each groove by brazing or other known methods, and in particular having no arcuate outer circumferential surface;
37, more preferably all heat seal blades 3
This is done by finishing the outer peripheral surfaces of 6 and 37 by polishing, grinding, etc. In addition, when the position regulating flanges 34 and 35 are configured separately from the roll body parts 32 and 33, the roll body parts 32 and 35 of those flanges 34 and 35,
33, attach the annularly formed flanges 34, 35 to the roll body parts 32, 33.
This is done by screwing to the end face of 3, and keying, brazing, etc. to the end of the main body part, and also preferably finishing polishing, grinding, etc.

Here, the radial distance between the heat seal blade circumferential surface and the flange circumferential surfaces 34a and 35a is as follows:
In relation to the thickness of the base material of the heat sealing material and the thickness of the resin layer that contributes to thermal welding, even if sufficient pressure is applied to the welding resin layer, the welding resin layer will not form as expected. The distance must be sufficient to provide the adhesive strength of 100 μm to several tens of μm in most cases.

According to the horizontal seal roll 31 configured in this manner, for example, one roll body portion 33 whose position is fixed is provided with the other roll body portion 32 which is movable forward and backward relative to the roll body portion 33, as described in the conventional example. By similarly bringing the circumferential surfaces 34a, 35a of the position regulating flanges 34, 35 into contact with each other, the opposing heat sealing blades 36, 37, as shown in FIG. Due to the existence of a predetermined radial distance between their circumferential surfaces and the flange circumferential surfaces 34a, 35a, they can be positioned very simply and precisely with the desired spacing, Such positioning will have excellent reproducibility.

Therefore, when heat-sealing material is passed between these heat-sealing blades 36 and 37 as shown by the imaginary line in the figure, the welded resin layer of the heat-sealing material is always properly heated and heated. Under pressure, the sheet will be sealed with sufficient strength.

FIG. 2 is an enlarged vertical cross-sectional view showing the result of such heat sealing on plastic film, which shows that the liquid pools and parting lines that occur due to insufficient pressure and melting are completely eliminated. It is clear that it is possible to sufficiently prevent the welding resin from being over-squeezed due to excessive pressure, and to always achieve proper heat sealing.

Also here, each heat seal blade 3
6 and 37 are high hardness surface portions 3 made of tool steel.
6a and 37a, its wear resistance is significantly improved, and even if sand or other hard substances get caught between the heat-seal blades, the surface of the heat-seal blades will remain intact. Since little or no unevenness occurs, proper heat sealing can be continued for a long period of time without the need for frequent clearance adjustment of the heat sealing blades 36, 37.

In addition, as described above, when the heat seal blade body parts 36a, 37a and/or the position regulating flanges 34, 35 are configured separately from the roll body parts 32, 33, it is necessary to cut them out. It is possible to significantly reduce the number of work steps required, and at the same time, it is possible to sufficiently improve the material yield.

FIG. 3 is a longitudinal cross-sectional view showing another embodiment of the present invention, which shows a horizontal seal roll manufactured in substantially the same manner as described in the previous example, with a heat sink attached to one roll main body portion 33. Only the seal blade 37 is connected to the circumferential surface 35 of the position regulating flange 35.
a, and the circumferential surface of the other heat sealing blade 36 is positioned within the same radius as the circumferential surface 34a of the position regulating flange 34.

In this example, the radial distance between the flange circumferential surface 35a and the circumferential surface of the heat sealing blade 37, in other words, the separation distance between the heat sealing blades 36 and 37 when both the flange circumferential surfaces 34a and 35a are in contact is determined as appropriate. By selecting , it is possible to always perform appropriate heat sealing on the heat sealing material by extremely simple clearance adjustment of the heat sealing blades 36 and 37, as in the above-mentioned example. As mentioned above, proper heat sealing can be continued for a long period of time and great manufacturing benefits can be brought about.

FIG. 4 is a longitudinal cross-sectional view showing still another embodiment of the present invention. Each heat-sealing blade main body portion 36 is made thinner in the direction opposite to the rotational direction and is hook-shaped.
A, 37a has a surface portion 36 made of tool steel on its outer surface.
b, 37 is fixed.

According to this example, the circumferential surfaces of the heat seal blades 36 and 37 are the same as those of the position regulating flanges 34 and 35.
By being located radially inwardly and by each heat-sealing blade 36, 37 having a surface portion 36b, 37b made of tool steel,
Not only can the same effects as those of the aforementioned embodiments be brought about, but also the heat sealing can be made more appropriate based on the elastic deformation and heat dissipation of the thin portions of the heat sealing blades 36, 37.

In addition, here, since the heat seal blades 36, 37 and, by extension, their main body parts 36a, 37a have a more complicated shape than the above-mentioned example, when cutting them from a single piece of material, The parts that require a significantly large number of man-hours are the roll body parts 32 and 33 and the heat seal blade body part 36.
By configuring 37a and 37a separately and combining them later, it is possible to achieve a sufficient reduction in the number of work steps, and at the same time, the material yield can also be greatly improved. I can do it.

In addition, in each of the above-mentioned embodiments, when the roll main body parts 32, 33 and the heat seal blade main body parts 36b, 37b are configured separately, one of the plurality of heat seal blades may be damaged by wear or other damage. If this occurs, proper heat sealing can be continued simply by replacing the heat sealing blade.

FIG. 5 is a sectional view showing still another embodiment of the present invention, in which one roll body portion 42 of a vertical seal roll 41 is made movable toward and away from the other roll body portion 43 whose position is fixed. , each pair of roll body portions 42, 4
Position regulating flanges 4 having the same diameter and abutting each other on the circumferential surface at at least two locations in the axial direction of No. 3;
4 and 45, respectively, the fifth
In the example shown in Figure a, both heat-sealing blades 4 are annular.
6 and 47, position regulating flange 4
These heat seal blades 46, 47 are located radially inward from the circumferential surfaces of the blades 4, 45
, heat seal blade main body parts 46a and 47a,
It is composed of surface portions 46b and 47b made of tool steel that are fixed to their outer peripheral surfaces. Also,
The example shown in FIG. 5b is a surface portion 47b made of tool steel.
Only the circumferential surface of one heat sealing blade 47 with
The other heat-sealing blade 46 having the same shape as the position regulating flange 44 is located within the same radius as the position regulating flange 44.

In the embodiments shown here as well, by positioning at least one heat sealing blade radially inward from the circumferential surface of the position regulating flange, the clearance adjustment between the two heat sealing blades 46 and 47 can be performed. By bringing the circumferential surfaces of the position regulating flanges 44 and 45 into contact with each other, heat sealing can be performed extremely easily. Based on the selected radial distance to the surface, it can always be correct.

Moreover, here, each heat seal blade 4
6, 47, a high hardness surface portion 46 made of tool steel;
By providing the heat sealing blades 46 and 47b, proper heat sealing can be continued for a long period of time without the need for frequent clearance adjustment of the heat sealing blades 46 and 47.

Here, the annular heat-sealing blade body portions 46a, 47a are further attached to the roll body portion 4.
Constructed separately from 2 and 43, and lock them with a key,
By assembling using known methods such as screwing and brazing, the manufacturing man-hours and repair costs of the vertical seal roll 41 can be significantly reduced, and the material yield can be reduced, as described in the previous embodiment. It can be improved sufficiently.

(Effects of the Invention) Thus, according to the present invention, the proximity limit position of the roll main body portion is specified by the abutment of each position regulating flange, so that the position of the roll body can be moved radially inward from the circumferential surface of the position regulating flange. The clearance between both heat seal blades can be adjusted as desired under the action of at least one of the heat seal blades located in the position, so the seal can be adjusted easily and with excellent reproducibility. The occurrence of defects can be almost completely eliminated.

Furthermore, by forming at least the surface portion of the heat-sealing blade extending in the length direction of the roll main body with tool steel, the wear resistance of the heat-sealing blade is significantly increased, and the surface of the heat-sealing blade is It is possible to extremely effectively prevent the occurrence of unevenness, and to continue proper heat sealing for a long time without the need for frequent clearance adjustment of the heat sealing blade.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view showing the sealing result by the heat seal roll shown in FIG. 1, and FIGS. 6th longitudinal cross-sectional view showing an example of
The figure is a schematic side view illustrating a conventional heat seal roll applied to an automatic filling machine, FIG. 7 is a longitudinal sectional view of the conventional heat seal roll, and FIG. 8 is an example of a clearance adjustment mechanism for the heat seal roll. The perspective view and FIG. 9 are enlarged vertical cross-sectional views showing a conventional heat-sealed portion. 31...Horizontal seal roll, 32, 33, 42,
43...Roll body part, 34, 35, 44, 4
5...Position regulation flange, 34a, 35a...Surrounding surface, 36, 37, 46, 47...Heat seal blade, 36a, 37a, 46a, 47a...Heat seal blade main body portion, 36b, 37b, 46b, 4
7b...Surface portion, 41...Vertical seal roll.

Claims (1)

[Scope of Claims] 1. A pair of roll body parts arranged close to each other in parallel and rotated in opposite directions, a heater built into each roll body part, and each pair of roll body parts. In a heat seal roll having heat seal blades extending in the length direction or circumferential direction and forming an arc shape in the circumferential direction, at least one of the pair of roll main body portions is spaced apart in the axial direction. Position regulating flanges that contact each other on the circumferential surface are provided at two locations, and at least one heat sealing blade of each pair of roll body portions is positioned radially inward from the circumferential surface of the position regulating flange, A heat seal roll characterized in that at least a surface portion of a heat seal blade extending in the length direction of the roll main body is formed of tool steel.