JP3960040B2 - Sheet forming device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet forming apparatus suitable for forming a ceramic green sheet used for manufacturing a multilayer electronic component such as a multilayer ceramic capacitor, and more particularly to a pull-up type sheet forming apparatus.
[0002]
[Prior art]
As a conventional ceramic green sheet forming apparatus, for example, there is a pulling type apparatus shown in FIG.
[0003]
The roll-shaped base film 3 is configured, for example, by bonding two polyethylene films. The roll-shaped base film 3 is pulled out by being driven by a nip roll 33 at the rear stage of the drying furnace 4 and immersed in the slurry 2 stored in the slurry tank 1 via the roller 34 and then pulled up in the vertical direction. It is done. The slurry 2 adhering to both surfaces of the base film 3 is dried in the drying furnace 4 to form a sheet on the base film 3, and each surface is wound by the winding rolls 6 and 7 through the rollers 35 and 36, respectively. .
[0004]
[Problems to be solved by the invention]
In such a conventional example, the thickness of the sheet to be formed is defined by the amount of slurry adhering to the base film 3 immediately after being pulled up from the slurry tank 1 and the movement of the slurry during the drying process.
[0005]
The amount of slurry adhering to the base film 3 is controlled and determined by the pulling speed of the base film 3, the viscosity of the slurry, and the thixotropy of the slurry. It is difficult to control the thickness level.
[0006]
In addition, since the base film 3 is fed only by the nip roll 33 at the rear stage of the drying furnace 4, a slight stress generated due to variations in drying shrinkage that occurs in the drying process induces bending of the base film 3 and the like. Therefore, there is a problem that the undried slurry flows according to the bent shape and the thickness variation is further deteriorated.
[0007]
The present invention has been made paying attention to such a point, and an object of the present invention is to provide a sheet forming apparatus with high thickness accuracy by reducing variation in sheet thickness.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
[0009]
That is, the sheet molding apparatus of the present invention is a means for feeding a film and immersing it in a slurry tank, applying the slurry to the surface of the film, lifting the film from the slurry tank, and drying the slurry adhering to the film. A sheet forming apparatus for drying and forming a sheet, comprising a smoothing means for smoothing the slurry on the coated surface of the film pulled up from the slurry tank, the smoothing means comprising a positioning part and a contact part The positioning portion positions the film and passes a predetermined position, and the contact portion is disposed so as to be spaced apart from the film surface at the predetermined position, The contact portion smoothes the slurry applied to the film surface.
[0010]
Here, the term “smooth” refers to being flat and smooth, and may be at least smoother than the coated surface before passing through the smoothing means.
[0011]
Further, the predetermined position may be a position where the contact portion can be disposed so as to be spaced apart from the film in the path of the film pulled up from the slurry tank.
[0012]
According to the present invention, the coated surface of the coated film that is pulled up from the slurry tank and passes through a predetermined position is brought into contact with a contact portion arranged at a certain distance from the film to smooth the coated surface. Therefore, a sheet having a thickness corresponding to the interval can be formed, and the sheet thickness accuracy can be improved as compared with the conventional example in which the sheet is formed by drying with a drying means while being pulled up from the slurry tank.
[0013]
In a preferred embodiment of the present invention, detection means for detecting the tension of the film, and control means for controlling the feeding amount of the film so that the tension of the film is constant based on the output of the detection means. It has.
[0014]
According to the present invention, since the film is fed with a constant tension, the film passes through a predetermined position without being slackened or bent, and is smoothed with high accuracy by the smoothing means. Further, since there is no occurrence of slack or deflection of the film even during the drying process, the undried slurry does not flow in accordance with the deflection shape or the like, and variations in sheet thickness can be prevented.
[0015]
In one embodiment of the present invention, it comprises first and second feeding means for feeding the film, each feeding means has at least one roll, and the first feeding means is more than the slurry tank. Is installed on the upstream side, the second feeding unit is installed on the downstream side of the drying unit, and the detection roller as the detection unit is installed between the first feeding unit and the slurry tank. Is.
[0016]
According to the present invention, the feeding means for feeding the film is installed on the upstream side of the slurry tank and the downstream side of the drying means to control the feeding amount of the film, so that the coating in the slurry tank, the smoothing process and the drying in the smoothing means The tension of the film at the time of drying in the means can be controlled with high accuracy, whereby the thickness accuracy of the sheet can be further increased.
[0017]
In another embodiment of the present invention, the second feeding means includes a plurality of suction rolls that respectively contact each coated surface of the film that has passed through the drying means.
[0018]
According to the present invention, since the dried film is sent by a plurality of suction rolls, each coating surface of the film comes into surface contact with each suction roll, and the driving force is transmitted and sent by line contact. Compared to the above, the sheet is not peeled off from the film and the feed roll is not idle.
[0019]
In a preferred embodiment of the present invention, the contact portion has a blade portion that extends linearly along the width direction of the film and contacts the coating surface, and the blade portion and the film at the predetermined position The separation interval can be adjusted.
[0020]
According to the present invention, the coating surface can be smoothed with high accuracy by the blade portion extending linearly in the width direction of the film, and the separation distance between the blade portion and the film at a predetermined position can be adjusted, so that the thickness of the sheet is variably adjusted. As a result, it is possible to cope with variations in thickness over time. Moreover, in the case of a two-sheet laminated film, it is possible to obtain films having different thicknesses on each surface.
[0021]
In another embodiment of the present invention, the positioning portion includes a guide groove through which the film passes, and a pressing roller that presses one surface of the film against the positioning surface of the guide groove, The contact portion has a pair of blade portions, and the pair of blade portions are arranged to face each other through the film passing through the guide groove.
[0022]
According to the present invention, the film is positioned so as to pass through a predetermined position by being pressed against the positioning surface of the guide groove with a pressing roller, and the two coating surfaces of the film are formed by a pair of blade portions arranged to face each other through the film. At the same time, it is possible to form a sheet that is smooth and has a thickness corresponding to the facing distance between the blade portions.
[0023]
In still another embodiment of the present invention, the positioning portion includes a first positioning roller on which one surface of the film is pressed and a second positioning roller on which the other surface of the film is pressed. The contact portion is in contact with the coating surface on the other side of the film that is in pressure contact with the first positioning roller, and the film is in pressure contact with the second positioning roller. And the second blade portion in contact with the coating surface on one side.
[0024]
According to the present invention, the coating surface on the other side of the film positioned by pressure contact with the first positioning roller is smoothed by the first blade portion, and one side of the film positioned by pressure contact with the second positioning roller By smoothing the coated surface with the second blade portion, a sheet having a thickness corresponding to the distance between each blade portion and the film can be formed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0026]
(Embodiment 1)
FIG. 1 is a configuration diagram of a sheet forming apparatus according to an embodiment of the present invention.
[0027]
The sheet forming apparatus according to this embodiment forms a ceramic green sheet in the same manner as the above-described conventional example. A base film 3 immersed in a slurry tank 1 and coated with a slurry 2 is removed from the slurry tank 1. This is a sheet forming apparatus of a pulling type that forms a sheet by drying the slurry adhered to the base film 3 in a drying furnace 4 as a drying means.
[0028]
In this sheet forming apparatus, a base film 3 drawn out of a base film roll 5, for example, a laminate of two polyethylene films, is immersed in the slurry 2 stored in the slurry tank 1, and then in the vertical direction. To be raised. The slurry adhering to both surfaces of the base film 3 is dried in the drying furnace 4 to form a sheet on the base film 3, and each surface is taken up by the take-up rolls 6 and 7 via the rollers 35 and 36. It is done.
[0029]
In this embodiment, in order to reduce the thickness variation of the sheet and increase the thickness accuracy, the following configuration is adopted.
[0030]
That is, the sheet forming apparatus of this embodiment basically includes a smoothing mold 8 as a smoothing means for smoothing both coated surfaces of the base film 3 that is pulled up from the slurry tank 1 and reaches the drying furnace 4; A tension detection roller 9 for detecting the tension of the base film 3 immersed in the slurry tank 1, and a nip roll 10 as a first feeding means for feeding the base film 3 upstream of the base film 3 in the feeding direction of the slurry tank 1. Based on the tension detected by the two detection rollers 11 and 12 as the second feeding means for feeding the base film 3 on the downstream side of the drying furnace 4 and the tension detecting roller 9, there is no occurrence of loosening or bending. A controller 13 for controlling the feed amounts of the nip roll 10 and both suction rolls 11 and 12 so as to obtain a tension of A scraping member 14 that scrapes off the slurry adhered to both ends in the width direction of the base film 3 pulled up from the Lee tank 1 and a correction roller (EPC roller) 15 that corrects meandering of the dried base film 3. ing.
[0031]
The smoothing mold 8 made of metal so as to obtain a high degree of dimensional accuracy passes through the base film 3 immersed in the slurry tank 1 and coated with the slurry 2 through a predetermined position as will be described later. And a pair of blade portions 16a and 16b as contact portions disposed so as to face each other at an equal interval from each surface of the base film 3 at the predetermined position. In this embodiment, the pair of blade portions 16a and 16b are arranged so that both surfaces of the two laminated films have the same thickness. However, as another embodiment of the present invention, the thickness of both surfaces is intentional. You may make it differ.
[0032]
By passing the base film 3 coated with the slurry 2 through the slit between the two blade portions 16a and 16b, both the coated surfaces of the base film 3 are smoothed, and the amount of the slurry 2 adhered is made constant. A sheet having a thickness corresponding to the interval is formed.
[0033]
FIG. 2 is a plan view of the smoothing mold 8, and FIG. 3 is a schematic side view for explaining the smoothing process by the pair of blade portions 16a and 16b. In these drawings, FIG. The same reference numerals are assigned to the parts to be performed.
[0034]
The smoothing mold 8 includes a pair of supports 17 and 18 equipped with the blades 16a and 16b, respectively. The supports 17 and 18 are arranged in the width direction of the base film 3 (the horizontal direction in FIG. 2). The support frames 19 and 20 on both sides are connected via connecting plates 21 and 22, respectively.
[0035]
Each blade part 16a, 16b is extended linearly along the width direction of the base film 3, and it is along the direction (up-down direction of FIG. 2) perpendicular | vertical to the width direction of the base film 3 by each support frame 19,20. It is supported so that it can be displaced. The blade portions 16a and 16b are in contact with the tips of the position adjusting screws 23 and 24 that are screwed into the screw holes formed in the connecting plates 21 and 22, respectively, so that the positions in the vertical direction are defined. It is like that. That is, each blade part 16a, 16b is regulated so that the separation distance from the base film 3 at the tip of each blade part 16a, 16b does not further widen by contacting each position adjusting screw 23, 24. The position adjusting screws 23 and 24 are adjusted so that the spacing interval can be variably set.
[0036]
A pair of U-shaped guide grooves 25 that guide both ends in the width direction of the base film 3 are configured by combining both supports 17 and 18, and one support 17 is equipped with a pressing roller 26. Has been. The pressing roller 26 positions the base film 3 so that the base film 3 passes through a predetermined position by pressing one surface of both ends of the base film 3 against the positioning surface 25a of the other support 18.
[0037]
Note that the adhering slurry 2 is scraped in advance by the scraping member 14 shown in FIG. 1 at both ends of the base film 3 guided by the guide groove 25, and the surface of the base film 3 is directly positioned. It is press-contacted to 25a and positioned accurately. The scraping member 14 is made of, for example, a rubber material. The scraping member 14 is not limited to a rubber material, and may be formed of a resin or other material.
[0038]
The positions of the blade portions 16a and 16b of the smoothing mold 8 are regulated by the position adjusting screws 23 and 24 so that the respective tips are positioned at regular intervals from the surfaces of the base film 3 to be positioned. Yes. The predetermined interval is set so as to correspond to a desired sheet thickness obtained through the drying furnace 4, and the position adjusting screws 23 and 24 are adjusted as necessary to regulate the blade portions 16a and 16b. The position can be adjusted.
[0039]
Each of the blade portions 16a and 16b of the smoothing mold 8 has high linearity along the width direction of the base film 3, and has high step accuracy. The distance between the facing blade portions 16a and 16b is, for example, about 50 to 200 μm, and the variation in linearity of each blade portion 16a and 16b is preferably about ± 1 μm, for example.
[0040]
The pair of blade portions 16a and 16b smoothes both coated surfaces of the base film 3 passing between the two, and makes the amount of the slurry 2 attached to be constant, thereby eliminating variations in thickness.
[0041]
In this way, the base film 3 whose both coated surfaces are smoothed by the smoothing mold 8 is the slurry 2 is dried in a drying furnace, but the base film 3 is not loosened or bent. Since it is sent at a constant tension, the undried slurry 2 does not flow due to slack or deflection, and thickness variation does not occur.
[0042]
Since the dried base film 3 is sent in contact with the suction rolls 11 and 12 on the surface, for example, the sheet is peeled off from the base film 3 as compared with a case where the base film 3 is sent in contact with a line like a nip roll. Can be effectively prevented. That is, when the base film 3 is fed, even if a stress is applied and the sheet is peeled off from the base film 3, it can be effectively prevented from spreading because it is in surface contact.
[0043]
As described above, according to this embodiment, both the coated surfaces of the base film 3 after the slurry coating that is fed with a constant tension so as not to be loosened or bent are formed on the double-edged portions of the smoothing mold 8. Since the sheet is smoothed by 16a and 16b and dried in the drying furnace 4 without being loosened or bent, it is possible to form a sheet with high thickness accuracy within 2% of thickness variation, for example.
[0044]
In this embodiment, the present invention is applied to a two-layer bonded film. However, the present invention can be similarly applied to a single film.
[0045]
(Embodiment 2)
FIG. 4 is a diagram showing a configuration before and after a slurry tank 1 according to another embodiment of the present invention, and portions corresponding to those of the above-described Embodiment 1 are denoted by the same reference numerals.
[0046]
In the above-described embodiment, both coated surfaces of the base film 3 are simultaneously smoothed by the pair of blade portions 16a and 16b arranged opposite to each other in the smoothing mold 8, but in this embodiment, the surface is immersed in the slurry tank 1. Then, the slurry 2 is applied and each coated surface of the base film 3 is smoothed one side at a time.
[0047]
That is, in this embodiment, the first positioning roller 27 on which one surface of the base film 3 pulled up from the slurry tank 1 is pressed and the second surface on which the other surface of the base film 3 is pressed. A positioning roller 28, a first blade portion 29 that is in contact with and smoothes the coating surface on the other side of the base film 3 that is pressed against the first positioning roller 27, and a base that is pressed against the second positioning roller 28 A first blade nip 31 and a second nip roll 31 and 32 for sandwiching the base film 3 between the second blade 30 for smoothing by contacting the coating surface on one side of the film 3 and the positioning rollers 27 and 28; And a scraping member 33 for scraping off portions of the slurry 2 corresponding to the positioning rollers 27 and 28 of the base film 3. The configuration of parts other than those shown in the drawing is the same as that of the above-described embodiment. Each positioning roller 27, 28 is made of metal, and the surface thereof is smoothed by a hard chrome treatment or the like.
[0048]
As shown in FIG. 5, the first and second positioning rollers 27 and 28 and the first and second nip rolls 31 and 32 are spaced along the width direction of the base film 3 (the left-right direction in FIG. 5). A plurality (three in this embodiment) are arranged with a gap. The portion of the base film 3 sandwiched between these rollers 27, 28, 31, 32 is scraped off the slurry 2 by the above-described scraping member 33, and this portion is pressed against the positioning rollers 27, 28 to form a base. The film 3 is positioned so as to pass through predetermined positions. For example, first and second blade portions 29 and 30 made of doctor blades are arranged so that the front end of the positioned base film 3 has a constant spacing interval.
[0049]
Note that the number and arrangement interval of the positioning rollers 27 and 28 and the nip rolls 31 and 32 arranged along the width direction of the base film 3 may be appropriately selected according to the width of the base film 3 and the like.
[0050]
FIG. 6 is a schematic perspective view showing the arrangement of the second positioning roller 28, the second nip roll 32, and the second blade portion 30.
[0051]
The second blade part 30 separated into two parts is brought into contact with the coated surface of the base film 3 that is positioned by being pressed against the second positioning roller 28, and the amount of the slurry 2 adhered is kept constant. As the thickness variation is reduced.
[0052]
In FIG. 6, the blade portion 30 is provided separately in two along the width direction of the base film 3 to smooth the coated surface of the base film 3, but not limited to this, at least one blade portion is provided. As long as the entire surface of the base film 3 in the width direction can be smoothed.
[0053]
The arrangement of the first positioning roller 27, the first nip roll 31 and the first blade portion 29 is the same.
[0054]
Other configurations and effects are the same as those of the above-described embodiment.
[0055]
【The invention's effect】
As described above, according to the present invention, the contact portion disposed at a certain distance from the film is brought into contact with the coating surface of the coated film that is pulled up from the slurry tank and passes through a predetermined position. Since the coated surface is smoothed, the thickness accuracy of the sheet can be improved as compared with the conventional example in which the sheet is formed by drying with a drying means while being pulled up from the slurry tank.
[0056]
In addition, since the film is fed with a constant tension, the film passes through a predetermined position without causing any slack or bending of the film. In the process, there is no occurrence of slacking or bending of the film, so that the undried slurry does not flow according to the bending shape or the like, and the variation in sheet thickness can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a sheet forming apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of the smoothing mold 8 of FIG.
FIG. 3 is a schematic side view for explaining smoothing processing by a pair of blade portions 16a and 16b.
FIG. 4 is a configuration diagram of a main part of another embodiment of the present invention.
FIG. 5 is a plan view showing a positional relationship among a positioning roller, a nip roll, and a blade portion.
FIG. 6 is a schematic perspective view showing an arrangement of a second positioning roller, a second nip roll, and a second blade portion.
FIG. 7 is a configuration diagram of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Slurry tank 2 Slurry 3 Base film 4 Drying furnace 8 Smoothing die 9 Tension detection roller 10 Nip rolls 11 and 12 Suction roll 13 Controllers 16a and 16b Blade portions 23 and 24 Position adjusting screw 25 Guide groove 25a Positioning surface 26 Pressing roller 27 , 28 Positioning rollers 29, 30 Blade part

Claims (7)

A sheet for feeding a film and immersing it in a slurry tank, coating the surface of the film with a slurry, lifting the film from the slurry tank, and drying the slurry adhering to the film by a drying means to form a sheet A molding device,
The smoothing means for smoothing the slurry on the coating surface of the film pulled up from the slurry tank, the smoothing means includes a positioning portion and a contact portion, and the positioning portion positions the film to a predetermined position. The contact portion is arranged so as to be separated from the film surface at the predetermined position with a certain interval, and the contact portion smoothes the slurry coated on the film surface. A sheet forming apparatus. Detecting means for detecting the tension of the film;
The sheet forming apparatus according to claim 1, further comprising: a control unit that controls a feeding amount of the film based on an output of the detection unit so that a tension of the film becomes constant. First and second feeding means for feeding the film, each feeding means has at least one roll, and the first feeding means is installed on the upstream side of the slurry tank, and the first feeding means The two feeding means are installed downstream of the drying means,
The sheet forming apparatus according to claim 2, wherein the detection roller as the detection unit is installed between the first feeding unit and the slurry tank. The sheet forming apparatus according to claim 3, wherein the second feeding unit includes a plurality of suction rolls that come into contact with the respective coating surfaces of the film that has passed through the drying unit. The said contact part has a blade part which extends linearly along the width direction of the said film, and contacts the said coating surface, The separation space | interval of this blade part and the film of the said predetermined position is adjustable. ~ 4 sheet forming apparatus. The positioning portion includes a guide groove through which the film passes, and a pressing roller that presses one surface of the film against a positioning surface of the guide groove,
The sheet forming apparatus according to claim 5, wherein the contact portion includes a pair of the blade portions, and the pair of blade portions are disposed to face each other through the film passing through the guide groove. The positioning unit includes a first positioning roller on which one surface of the film is pressed and a second positioning roller on which the other surface of the film is pressed,
The contact portion includes a first blade portion that contacts a coating surface on the other side of the film that is in pressure contact with the first positioning roller, and a first side of the film that is in pressure contact with the second positioning roller. The sheet forming apparatus according to claim 5, further comprising a second blade portion that contacts the coated surface.

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