JP4191283B2 - Multi-layer coating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer coating apparatus that continuously coats a web with a plurality of coating liquids, and more specifically, a plurality of lip-type nozzle heads arranged at intervals around a backing roll. The present invention relates to a multilayer coating apparatus for forming a coating layer.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a slide type coating apparatus, a lip type coating apparatus, or the like is known as an apparatus that performs multilayer coating on a web that is continuously supported by a backup roll. A so-called slide type multilayer coating apparatus includes a plurality of slots for ejecting the coating liquid, and a slide surface for supplying the ejected coating liquid to the web surface supported by the backing roll and transported from each slot. By supplying the working liquid to the slide surface and flowing along the slide surface, the coating liquid is sequentially laminated downward on the slide surface, and multilayer coating is simultaneously performed on the continuously conveyed web surface.
[0003]
The so-called lip type coating apparatus forms a plurality of slots for supplying the coating liquid to the opposing surface (lip surface) of the nozzle head or die backing roll, and supplies the coating liquid from each slot to the lip surface. In this manner, the layers are sequentially laminated from the front to the upper layer from the surface of the web that is continuously conveyed, and multilayer coating is simultaneously applied to the continuously conveyed web.
[0004]
[Problems to be solved by the invention]
Multi-layer coating with the above-described coating apparatus is difficult to adjust the coating thickness of each layer, and it is difficult to coat thickly due to the generation of bubbles at high speed, and almost no shearing force is applied during coating. The coating accuracy was poor. Specifically, in a slide-type coating apparatus, it is necessary to select a coating solution having a specific viscosity or special physical properties for each layer, which limits the coating speed or application of the coated product, and Work thickness unevenness occurred. Further, in the lip type coating apparatus, it is difficult to adjust the gap between the lip surface and the web and the relation of the coating liquid physical properties. In high-speed coating, bubbles were generated in the coating solution and coating thickness unevenness occurred.
[0005]
The present inventor was devised to cope with the above-mentioned problems, and researched on speeding up various multi-layer coating apparatuses, and by arranging a plurality of coating heads at intervals, high-speed coating was performed. It was possible to adjust the thickness of each layer easily.
[0006]
An object of the present invention is to provide a multilayer coating apparatus that can easily adjust the thickness of each layer, prevent the generation of bubbles and the like, and can be applied without causing unevenness at high speed.
[0007]
[Means for Solving the Problems]
And the multilayer coating apparatus of this invention as a means for achieving the said objective arrange | positions a 1st nozzle head under the backing roll, and is supplying the 1st coating liquid from the exit of the said 1st nozzle head. The second nozzle head is disposed opposite to the backing roll at a distance from the first nozzle head, sprayed by applying pressure and coated on the web that is supported by the backing roll, and the second nozzle head. A multi-layer coating apparatus that sprays a second coating liquid on a first coating liquid of the web by spraying a second coating liquid from a nozzle head at a pressure, wherein the first nozzle head comprises: A head body, a doctor edge, and a lid, and a lower liquid reservoir chamber is provided in the width direction of the interior, and an outlet passage is provided from the lower liquid reservoir chamber to the outlet in front of the doctor edge, The doctor edge around the exit From there, leaving a gap on the surface facing the backing roll, a liquid reservoir wall is erected, and a portion formed by the lower peripheral surface of the backing roll, the liquid reservoir wall, and the doctor edge front surface The upper liquid reservoir chamber is formed to expand forward from the outlet of the outflow path to be larger than the volume of the outflow path, and the second nozzle head includes a second head main body portion and an ejection head portion, A coating liquid inlet is provided in the head main body, a jet outlet for supplying the second coating liquid to the web surface is provided in the ejection head, and the ejection head is located near the backing roll and has a lip surface on the opposite surface. The lip surface of the ejection head portion retreats the upstream upstream lip surface to a step with respect to the backing roll from the downstream downstream lip surface, and tilts the upstream lip surface. By the angle between the tangent of the backing roll and said upstream lip surface, larger than the angle which the tangent forms of the downstream lip surface and said backing roll, said second nozzle head The shear pressure determined by the gap between the downstream lip surface and the web is lower than the linear pressure due to the blade edge of the doctor edge in the first nozzle head. Apply the second coating solution.
[0009]
In the multilayer coating apparatus of the present invention, the first nozzle head and the second nozzle head are arranged around the backing roll at an interval, and the first nozzle head is composed of a head body, a doctor edge, and a lid. An outlet for supplying the coating liquid to the main body in front of the doctor edge is provided, and a liquid reservoir wall is erected leaving a gap on a surface facing the backing roll, and a lower peripheral surface of the backing roll, the liquid reservoir wall, and the The portion formed by the front surface of the doctor edge is formed as an upper liquid reservoir chamber that is expanded forward from the outlet of the coating liquid to be larger than the volume of the outflow passage, and the coating liquid is stored in the upper liquid reservoir chamber for coating. And evenly coat the tip of the doctor edge. The second nozzle head includes a second head main body portion and a jet head portion, and is provided with a coating liquid inlet of the second head main body portion, and supplies the second coating liquid from the jet head portion to the web surface. A jet outlet is provided, and the coating liquid is layered on the lip surface at the tip of the jet head, and coating is performed at high speed without unevenness.
[0010]
In the present invention, the web means a flexible belt-like material such as a metal strip, paper, film, cloth, or sheet. The volume of the outflow path means the volume of the outflow path between the lower liquid reservoir and the outlet.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 5 show an embodiment of the present invention, FIG. 1 is a side view showing a multilayer coating apparatus according to the present invention, and FIG. 2 is a block diagram for controlling the pressure of the first nozzle head. 3 is a front view of the second nozzle head, FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. 5 is an enlarged view of the ejection head portion.
[0012]
(Outline of structure of multilayer coating apparatus 10)
The multilayer coating apparatus 10 is opposed to the web F that is supported by the backing roll 12 and travels, and a first nozzle head 14 that is disposed below the backing roll 12 and a first nozzle head 14 that is disposed at a distance from the first nozzle head 14. And a two-nozzle head 15.
[0013]
The first nozzle head 14 generally includes a head main body 16, a doctor edge 18, and a lid body 22, and the second nozzle head 15 includes a nozzle main body portion 52 and an ejection head portion 54.
[0014]
Then, the first coating liquid is applied from the first nozzle head 14 so as to face the web F supported by the backing roll 12, and then the first nozzle head is applied on the coating layer. The second coating liquid is applied from the second nozzle head 15 arranged at a distance from the first nozzle head 15.
[0015]
(Structure of the first nozzle head 14)
The head main body 16 of the first nozzle head 14 has substantially the same width as the backing roll 12, and a doctor edge 18 is provided on the upper part. The doctor edge 18 has a comma shape in which the longitudinal sectional shape is formed in an arc shape. The leading edge of the doctor edge 18 and the backing roll 12 are arranged with a gap, and the web F travels through this gap. The front surface 16a of the head body 16 is formed in a flat surface, and a coating solution supply port 20 is opened in the front surface 16a.
[0016]
A lid 22 is detachably attached to the front upstream side of the head body 16 opposite to the side where the doctor edge 18 is provided by means of bolts. On the rear surface of the lid 22, a lower liquid reservoir chamber 26 is formed extending in the width direction inside the first nozzle head 14 by a recess 24 in the width direction. In the upper part of the lower liquid reservoir chamber 26, an outflow path 28 is formed continuously in the width direction to the first liquid reservoir chamber 26. The outflow path 28 extends vertically upward and reaches an outlet 28 a formed between the front part of the doctor edge 18 and the front end part of the first nozzle head 14. The length of the outlet 28a in the width direction is set to the approximate coating width of the web F. In order to change the coating width of the web F, the length of the lid 22 in the width direction is changed. A liquid reservoir wall 30 is provided in the upper part of the front surface of the lid 22 so as to store the coating liquid supplied from the outlet 28a.
[0017]
The liquid reservoir wall 30 has substantially the same width as the lid body 22 and is detachably attached to the upper part of the front surface of the lid body 22 by bolts 31. A gap for running the web F remains between the upper end of the liquid reservoir wall 30 and the lower end surface of the backing roll 12. An upper liquid reservoir chamber 32 is formed by the liquid reservoir wall 30 and the doctor edge 18 or the like.
[0018]
The upper liquid reservoir chamber 32 stores the first coating liquid so as to be applied to the web F, and is a space formed by the front surface of the doctor edge 18, the upper surface of the lid 22, and the rear surface of the liquid reservoir wall 30. The both end surfaces of this space are closed by a partition wall disposed between the upper surface of the first nozzle head 14 and the lower peripheral surface of the backing roll 12. The volume of the upper liquid storage chamber 32 is made larger than the volume of the outflow passage 28 because the front of the outflow passage 28 is expanded from the outlet 28a. The partition wall is slidably provided between the upper surface of the first nozzle head 14 and the lower peripheral surface of the backing roll 12. The bottom surface of the partition wall is formed so as to close the outlet 28a of the outflow passage 28 opened in the width direction.
[0019]
A slit 36 is provided below the doctor edge 18 of the head body 16. One end of the slit 36 opens in the width direction on the rear upper surface of the head main body 16, and is inclined downward toward the front. Further, a plurality of adjustment bolts 38 penetrates at equal intervals in the width direction so as to be orthogonal to the slit 36. The end of the adjustment bolt 38 faces the rear surface 16b of the first nozzle head 14, and the width of the slit 36 can be adjusted by adjusting the screwing degree of the adjustment bolt 38 from the rear surface 16b. By changing the width of the slit 36, the cutting edge of the doctor edge 18 moves up and down, and the width can be adjusted by 2 to 3 μm in the vertical direction. Since a plurality of adjustment bolts 38 are provided in the width direction, adjustment can be made with the adjustment bolt 38 closest to the cutting edge to be moved up and down. Further, the first nozzle head 14 is provided with a holding member 40 that holds the first nozzle head 14.
[0020]
The holding member 40 is provided below the first nozzle head 14 and is connected to position adjusting driving means such as a servo motor, an air cylinder, and a hydraulic cylinder. The first nozzle head 14 held by the holding member 40 can approach and separate from the backing roll 12. The driving means is provided at the center of the first nozzle head 14 by driving, and adjusts the position of the end in the center direction of the backing roll 12 with a width of 20 to 30 μm. In addition, a scale holding member is disposed below the holding member 40. The scale holding member incorporates a position measuring scale and detects the position of the first nozzle head 14 relative to the backing roll 12.
[0021]
A first thickness measuring device 90 that measures the coating thickness of the first coating liquid is provided in the traveling path of the web F between the first nozzle head 14 and the second nozzle head 15. As a type of the thickness measuring device 90, a β-ray thickness meter, an infrared thickness meter, or the like is used. The thickness signal measured by the thickness measuring device 90 is output to the microcomputer 48 of the control device and compared with the set value of the thickness by the microcomputer 48. As will be described later, the supply amount of the first coating liquid, the supply pressure, and the backing roll 12 and the doctor edge 18 are adjusted so that the coating thickness becomes a set value.
[0022]
Further, the microcomputer 48 is connected to a motor tachometer, a gap sensor and the like of the backing roll 12 (not shown), and receives a rotation detection signal of the backing roll 12 and a gap detection signal at a predetermined position in the left-right direction of the backing roll 12 and the doctor edge 18. It is supposed to be.
[0023]
The first pump 46 that controls the supply amount and supply pressure of the first coating liquid is connected to the first coating liquid supply port of the head body 16. The pump 46 is connected to the microcomputer 48 and is controlled by an operation signal DS from the microcomputer 46 to adjust the supply amount and supply pressure of the coating liquid. The supply pressure of the first coating liquid is detected by measuring the internal pressure of the upper liquid reservoir chamber 32 with a pressure gauge 49. The pressure gauge 49 is connected to the microcomputer 48 and outputs the measured pressure to the microcomputer 48 by a pressure signal AS that is an electrical signal.
[0024]
(Control method of the first nozzle head 14)
(1) First control system
First, the first control system will be described.
[0025]
As a method for controlling the coating thickness of the first coating solution, the supply amount and the supply pressure are controlled based on the principle that the coating thickness is determined by the amount of the coating solution to be supplied.
[0026]
That is, the discharge amount per unit time of the first pump 46 is determined by the product of the line speed, the coating width, and the coating thickness, that is, the volume of the coating amount. In addition, the coating thickness in this case is a coating thickness in a wet state. Further, the discharge amount of the coating liquid per unit time is determined by the rotational speed of the pump 46. Therefore, the necessary rotation speed N (rpm) of the first pump 46 is determined by the equation (1).
[0027]
N = D x W x V / K1 x Q (1)
Where D is the wet coating thickness (mm), W is the coating width (mm), V is the line speed (m / min), Q is the discharge amount per rotation of the pump 46 (cc / REV), K1 Is a constant.
[0028]
Q can be considered a constant if the pump type of the pump 46 is determined.
N = D x W x V / K2 (2)
become that way.
[0029]
However, K2 = K1 × Q.
[0030]
Therefore, if the wet coating thickness D and the coating width W are numerically input to the microcomputer 48, and the line speed V of the backing roll 12 is input to the microcomputer 48 via the A / D converter, the microcomputer 48 (2) The motor for rotating the pump 46 is controlled so that the pump rotational speed N obtained by the equation is obtained.
[0031]
Thereby, the rotation speed of the pump 46 automatically follows the change in the line speed V, and the coating liquid can always be applied with the same coating thickness and the same coating width.
[0032]
(2) Second control system
Next, the second control system will be described.
[0033]
Since it is considered that there is no change in the coating thickness or coating width during the coating operation, the coating thickness D and coating width W in equation (2) are considered to be constants. Therefore, equation (2) becomes
N = K3 xV (3)
It is expressed as However, K3 = D × W / K2.
[0034]
By the way, in the coating thickness D, when the average value Dp is obtained from the thickness measuring device 90 with respect to the total coating width, the constant K3 is given as follows.
[0035]
K3 = Ds / Dp x K0 (4)
However, Ds is a set coating thickness and K0 is a constant.
[0036]
By substituting K3 obtained by the equation (4) into the equation (3), the rotational speed of the pump 46 corresponding to the set coating thickness becomes as the equation (5).
[0037]
N = Ds x V x K0 / Dp (5)
Thereby, the rotation speed of the pump 46 automatically follows the change in the line speed V, and the coating liquid can always be applied with the same coating thickness and the same coating width.
[0038]
Further, as control for controlling the coating thickness by adjusting the gap between the doctor edge 18 and the backing roll 12, the coating thickness in the width direction is measured by dividing it into n sections by the first thickness measuring device 90, and the gap The sensor measures the gap between the doctor edge 18 and the backing roll 12 and stores it in the microcomputer 48. The microcomputer 48 stores the average coating thickness of each of these n sections from the left side of the nozzle as D1 (t), D2 (t)... Dn-1 (t), Dn (t).
[0039]
Then, the microcomputer 48 calculates the following equations (6) to (8) according to D1 (t), D2 (t)... Dn-1 (t), Dn (t) input at regular intervals. The gap between the left side of the doctor edge 18 and the left side of the backup roll 12 is GL (t), the gap between the right side of the doctor edge 18 and the right side of the backup roll 12 is GR (t), the central part of the doctor edge 18 and the central part of the backup roll 12 GC (t) is obtained for the gap of.
[0040]
GL (t) = GL (t-1) + {(D2 (t) + Dn-1 (t)) / 2-D2 (t)} × K4 (6)
GR (t) = GR (t-1) + {(D2 (t) + Dn-1 (t)) / 2-D6 (t)} × K4 (7)
GC (t) = GC (t-1) + {(D2 (t) + Dn-1 (t)) / 2-D4 (t)} × K4 (8)
However, GL (t-1), GR (t-1), and GC (t-1) are gaps between the doctor edge 18 and the backing roll 12 obtained by the equations (6) to (8) a predetermined time ago. K4 is a coating coefficient.
[0041]
The microcomputer 48 measures the gap at regular intervals so that GL (t), GR (t), and GC (t), and drives the gap motor to correct the gap between the doctor edge 18 and the backing roll 12. .
[0042]
Thereby, the coating thickness in the width direction of the web F is always controlled, and the coating thickness is not uneven. In this case, the number n of n sections in the width direction is preferably 3 or more, although it depends on the width of the web F. In order to improve the accuracy of the thickness, a larger number is preferable, but it may be selected depending on the width of the web F. Further, the coating thickness can be adjusted with higher accuracy by controlling the rotation speed of the pump 46 and adjusting the position of the holding member 40 together.
[0043]
Thus, after the first coating liquid is applied to the web F with the thickness controlled by the first nozzle head 14, the first coating liquid is subsequently laminated on the layer of the first coating liquid. 15, the second coating liquid is applied.
[0044]
(Structure of the second nozzle head 15)
The second nozzle head 15 is disposed at a distance from the first nozzle head 14, and is formed by the nozzle main body portion 52, the ejection head portion 54, and the support member 56. Then, the second coating liquid is applied to the coating layer of the web F which is supported by the backing roll 12 by the second nozzle head 15 and coated with the first coating liquid by the first nozzle head 14. Is applied.
[0045]
The nozzle body 52 of the second nozzle head 15 is configured by removably screwing a front body 58 and a rear body 60 with a plurality of bolts 62.
[0046]
The front body 58 is provided with a supply port 64 for supplying the second coating liquid to the second nozzle head 15, and a manifold 66 connected to the supply port 64 is provided extending in the width direction. A flow path 68 connected to the manifold 66 is provided at the interface between the front body 58 and the rear body 60. Engaging protrusions 70 and 72 are provided on the front end surfaces (surfaces facing the backing roll) of the front and rear bodies 58 and 60, respectively, and a concave surface 74 is formed between the engaging protrusions 70 and 72. The ejection head portion 54 is fitted to the concave surface 74, and the plurality of bolts 76 are screwed into the engaging projections 70 and 72 to be tightened, so that the nozzle body portion 52 and the ejection head portion 54 can be attached and detached. It is integrated.
[0047]
The ejection head portion 54 is configured by combining a front head 54a and a rear head 54b, and is formed with a bottom portion that fits into the concave surface 74 of the nozzle body portion 52 and a tip portion 80 that protrudes toward the backing roll 12, and is formed inside. A liquid reservoir 82 is provided. A jet outlet 84 is provided at the tip of the tip portion 80, and a coating liquid flow path 86 that is connected from the jet outlet 84 through the liquid reservoir 82 to the flow path 68 of the nozzle body 52 is provided.
[0048]
The front lip surface 88a and the wall forming the jet port 84 in front of the ejection port 84 of the ejection head portion 54 (running upstream side) are stepped away from the circumferential surface of the backing roll 12 from the rear lip surface 88b and the rear wall. The second coating liquid is more retained in front of the spout 84. Further, the inclination of the front lip surface 88a facing the backing roll 12 in front of the jet outlet 84 is an angle formed with the tangent to the backing roll 12 and larger than the angle formed by the rear lip surface 88b behind the jet outlet 84. As a result, the second coating liquid can be laminated on the first coating liquid layer with a low shear force.
[0049]
The support member 56 of the second nozzle head 15 is configured in the same manner as the holding member 40 of the first nozzle head 14, and is connected to position adjusting drive means such as a servo motor, an air cylinder, and a hydraulic cylinder. This driving means is arranged in the radial direction of the backing roll 12 and adjusts the second nozzle head 15 with respect to the backing roll 12 in the center direction with a width of 2 to 30 μm. The support member 56 is provided with a scale holding member. The scale holding member incorporates a displacement measuring scale and detects the displacement of the support member 56. The adjustment of the coating thickness in the second nozzle head 15 is such that the thickness of the second coating layer coated on the first coating layer becomes a set value so that the jet nozzle of the second nozzle head 15 This is performed by adjusting the size of the gap between the front and rear lip surfaces 88a and 88b and the peripheral surface of the backing roll 12, the supply pressure of the second coating liquid, and the like. As a 2nd coating layer, 5-30% of the thickness of a 1st coating liquid is laminated | stacked on the thickness of several micrometers-several dozen micrometer.
[0050]
The supply of the second coating liquid in the second nozzle head 15 is performed in substantially the same manner as in the first nozzle head 14. A second pump 100 is provided connected to the second coating liquid supply port 64, and this second pump 100 is controlled by an operation signal from the microcomputer 48 to adjust the supply pressure of the second coating liquid. Yes. The supply pressure of the coating liquid is detected by measuring the internal pressure of the liquid reservoir 82 with the pressure gauge 102. The pressure gauge 102 outputs the measured pressure to the microcomputer 48 by a pressure signal that is an electrical signal. Further, a thickness measuring device 92 for measuring the coating layer thickness after the second layer is applied is provided in the travel path of the web F after the second nozzle head 15. The thickness signal measured by the thickness measuring device 92 is output to the microcomputer 48, and the microcomputer 48 compares the thickness signal with the set value of the thickness. Similar to the thickness of the first coating layer, the tip 80 of the second nozzle head 15 and the backing The gap between the rolls 12 or the supply pressure of the coating liquid is adjusted to control the set value.
[0051]
(Operating state of the multilayer coating apparatus 10)
Next, the operation state of the multilayer coating apparatus 10 will be described.
[0052]
The thickness of the first coating liquid on the web F of the multilayer coating apparatus 10 is determined by the gap between the backing roll 12 and the doctor edge 18 and the internal pressure of the upper liquid reservoir chamber 32. The coating thickness of the second coating liquid is adjusted by adjusting the supply amount of the second coating liquid and the size of the gap between the lip surface and the web F surface. The web F is run in the gap between the backing roll 12 and the doctor edge 18. The first coating liquid diffuses in the width direction of the first nozzle head 14 in the lower liquid reservoir chamber 26 from the first pump 46, and is uniformly ejected from the outlet 28 a into the upper liquid reservoir chamber 32 through the outflow path 28. Then, the inside of the upper liquid reservoir chamber 32 is maintained at a constant pressure (hereinafter referred to as a reference pressure). This reference pressure is set so that the first coating liquid fills the upper liquid reservoir chamber and does not overflow from the gap between the liquid reservoir wall 30 and the backing roll 12.
[0053]
The web F passes through the upper liquid reservoir chamber 32 filled with the first coating liquid, travels to the doctor edge 18, and the coating liquid is applied by the linear pressure by the blade edge of the doctor edge 18. In this case, when the coating liquid passes through the narrow outflow path 28, the pressure of the coating liquid is made uniform, and the upper liquid reservoir chamber 32 expands forward from the outlet 28 a of the outflow path 28 and flows out. Therefore, it is easy to maintain the inside of the upper liquid reservoir chamber 32 at a reference pressure higher than the atmospheric pressure, so that the web F can be retained from the gap between the liquid reservoir wall 30 and the backing roll 12. When transported to 32, air does not enter the upper liquid reservoir chamber 32, and bubbles do not occur in the coating layer.
[0054]
In addition, since the doctor edge 18 of the first nozzle head 14 is a comma type, the volume of the upper liquid reservoir chamber 32 gradually decreases as it approaches the blade edge, and the pressure applied to the web F gradually increases accordingly. In addition, the first coating liquid is prevented from overflowing outside the upper liquid reservoir chamber 32 by adjusting the pressure. For this reason, the entrained flow of the coating liquid accompanying the movement of the web F and the jet flow of the coating liquid from the outlet 28a of the outflow path 28 do not become an unstable flow as a swirling flow in the same direction. Therefore, the amount of the coating liquid on the surface of the web F before reaching the doctor edge 18 does not change in the width direction, and the coating amount on the web F does not cause unevenness in the width direction.
[0055]
When the coating thickness in the width direction deviates from the set thickness due to the first nozzle head 14 being bent in the width direction, the center portion, the left and right side portions of the first nozzle head 14 are driven by the driving means of the holding member 40. Is displaced vertically to correct the coating thickness. Since the microcomputer 48 also inputs various measured values, when the first coating layer thickness measured by the first thickness measuring device 90 deviates from the set value, the microcomputer 48 causes the main factor to rotate the first pump 46. Whether it is based on a number or a change in the gap, it can be compared with the respective measured values before a certain time, and if they have changed, the changed ones can be adjusted.
[0056]
Subsequently, the web F is run on the backing roll 12 and the second nozzle head 15 disposed at a distance from the first nozzle head 14 and the second coating on the first coating liquid layer. The liquid is laminated. The ejection head portion 54 of the second nozzle head 15 forms a front lip surface 88a on the front side and a rear lip surface 88b on the rear side with the ejection port 84 interposed therebetween. The second coating liquid fed to the supply port 64 is uniformly dispersed in the width direction by the manifold 66, and the pressure is made uniform by the liquid reservoir 82 from the flow channel 68 through the flow channel 86 of the ejection part 54, and the ejection port. 84 is supplied to the front lip surface 88a and the rear lip surface 88b, and is applied onto the first coating liquid layer of the web F. At this time, since the front lip surface 88a and the rear lip surface 88b are simply formed on the surface facing the web F, the second coating liquid can be applied with a low shear force. Therefore, the uneven thickness of the coating film can be reduced.
[0057]
When the internal pressure in the upper liquid storage chamber 32 of the first coating liquid rises above the reference pressure due to external factors such as uneven rotation of the first pump 46, changes in the viscosity of the coating liquid, changes in the liquid temperature, etc., the pressure gauge The fact that the internal pressure has increased is transmitted to the microcomputer 48 by the pressure signal AS. The microcomputer 48 reduces the pressure at which the coating liquid of the first pump 46 is pumped by the operation signal DS. When the pumping pressure is lowered, the internal pressure of the upper liquid reservoir chamber 32 is lowered to the original pressure. Conversely, when the internal pressure of the upper liquid reservoir chamber 32 falls below the reference pressure, the microcomputer 48 increases the pressure at which the coating liquid of the first pump 46 is pumped to increase the internal pressure of the upper liquid reservoir chamber 32.
[0058]
Then, the blade edge of the doctor edge 18 is brought closer to a straight line by finely adjusting the undulation of the blade edge by changing it by 2 to 3 μm vertically by the adjusting bolt 38. The size of the swell and the amount of change in adjustment are determined by measuring the coating thickness of the coated web F with the thickness measuring device 90 and confirming whether the coating liquid has been applied uniformly in the width direction. When the thickness in the width direction is uneven, the straight line of the cutting edge of the doctor edge 18 of the first doctor edge 14 is adjusted. The thickness unevenness at the second doctor edge may be adjusted by making the gap between the lip surface 88b and the web F uniform.
[0059]
When the lid 22 is removed from the first head main body 16, the first head main body 16 is formed on a flat surface, so that it is easy to clean the coating liquid and dust adhering to the front surface 18a. Further, when the width of the lid 22 attached to the first head body 16 is changed, the width of the outlet 28a at the outlet of the outflow passage 28 is changed, and the coating width of the web F can be changed. Further, by sliding the partition wall 34 in the width direction, the width of the web 28 can be changed by changing the width of the outlet 28a.
[0060]
When the gap between the second nozzle head 15 and the backing roll 12 is deviated in the width direction and uneven coating thickness occurs, the tightening of the mounting bolt 76 is adjusted to adjust the gap near the bolt. To adjust the thickness of the second coating liquid layer, first, the gap between the backing roll 12 and the lip surface of the ejection head is adjusted by changing the position of the second nozzle head 15 by moving the support member 56 forward and backward by the driving means. To do. Alternatively, a gap motor is provided, and the gap motor is driven to adjust the gap with the lip surface of the ejection head.
[0061]
(Example of change)
In addition, this invention is not limited to the embodiment mentioned above, The thing which can be deform | transformed within the range which does not change the main point of this invention is included.
[0062]
Incidentally, in the above description, each of the first nozzle head and the second nozzle head is shown as an example in which one layer is applied, but one or both may have a structure in which a plurality of coating liquids are applied. Thus, when a plurality of nozzle heads are used, the adjustment of the layer is facilitated, and the layer thickness can be made uniform. Further, in the drawing, the arrangement of the first nozzle head and the second nozzle head is shown in a mode in which they are arranged approximately 90 degrees apart from the lower side of the backing roll along the line passing through the center line, but it is of course not limited to this position. .
[0063]
In addition, the thickness of the first coating layer is controlled by measuring the gap between the backing roll 12 and the doctor edge 18 with a gap sensor, and controlling the gap motor so that the coating thickness in the width direction is calculated and becomes a set value. However, the position of the first nozzle head 14 may be adjusted by driving the driving means of the holding member 40. In this case, the position of the first nozzle head 14 is measured with a position measurement scale, and the position is adjusted so as to maintain the set coating thickness.
[0064]
【The invention's effect】
In the multilayer coating apparatus according to the first aspect of the present invention, since the first nozzle head and the second nozzle head are arranged at an interval, the adjustment for each nozzle head can be performed, the layer thickness can be easily adjusted, and unevenness is caused. It can prevent and improve accuracy, and can be applied at high speed. Further, the coating amount of the first nozzle head of the web is determined by the linear pressure caused by the blade edge of the doctor edge after passing through the upper liquid reservoir chamber filled with the coating liquid. In this case, the upper liquid reservoir chamber is expanded forward from the outlet of the outflow passage so as to be larger than the volume of the outflow passage. Therefore, the inside of the upper liquid reservoir chamber can be easily maintained at a reference pressure higher than the atmospheric pressure. Air can be prevented from entering inside, and air bubbles can be prevented from being generated. Since the coating amount at the second nozzle head is determined by the gap between the lip surface and the web, the coating thickness can be adjusted by adjusting the gap between the lip surface and the web, that is, the shear pressure.
[0065]
Also, Since the first nozzle head is applied with high accuracy and then the second nozzle head is applied thereon, even if the second nozzle head is applied with low shear force, unevenness can be prevented and a coating film can be formed with high accuracy. The device can be made inexpensive.
[Brief description of the drawings]
FIG. 1 is a side view showing a multilayer coating apparatus according to the present invention.
FIG. 2 is a block diagram for performing pressure control of first and second nozzle heads.
FIG. 3 is a front view of a second nozzle head.
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is an enlarged view of the ejection head.
[Explanation of symbols]
10 ... Multilayer coating equipment
12 ... backing roll
14 ... 1st nozzle head
15 ... Second nozzle head
16 ... 1st head body
18 ... Doctor edge

Claims (1)

A first nozzle head is disposed below the backing roll, and the first coating liquid is ejected from the outlet of the first nozzle head under pressure to be applied to the web that is supported by the backing roll and travels. The second nozzle head is arranged facing the backing roll at a distance from the first nozzle head, and the second coating liquid is ejected from the jet nozzle of the second nozzle head under pressure. A multi-layer coating apparatus for coating on the first coating liquid of the web,
The first nozzle head is
Consists of a head body, a doctor edge, and a lid, and a lower liquid reservoir chamber is provided in the width direction of the interior.
Providing an outflow path from the lower liquid reservoir chamber to the outlet in front of the doctor edge;
From the doctor edge around the outlet of the outflow path to the front, leaving a gap on the surface facing the backing roll, standing a liquid storage wall,
A portion formed by the lower peripheral surface of the backing roll, the liquid reservoir wall, and the front surface of the doctor edge is formed as an upper liquid reservoir chamber in a forward direction from the outlet of the outflow path to be larger than the volume of the outflow path;
The second nozzle head is
Consists of a second head body and a jet head,
A coating liquid inlet is provided in the second head main body, and a jet outlet for supplying the second coating liquid to the web surface is provided in the ejection head.
The ejection head portion is provided close to the backing roll and forms a lip surface on the opposite surface,
The lip surface of the ejection head part is configured such that the upstream upstream lip surface is stepped backward with respect to the backing roll from the downstream downstream lip surface, and the upstream lip surface is inclined so that the upstream lip surface is inclined. An angle formed by a surface and a tangent line of the backing roll is larger than an angle formed by the tangent line of the downstream lip surface and the backing roll,
Applying a second coating liquid by setting a shear pressure determined by a gap between the downstream lip surface and the web in the second nozzle head to be lower than a linear pressure by a blade edge of the doctor edge in the first nozzle head ;
A multilayer coating apparatus characterized by that.

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