JP4974580B2 - Die system coating apparatus and coating method - Google Patents

Description

  The present invention relates to a die-type coating apparatus and a coating method for applying a coating liquid to a continuous strip-shaped web such as plastic film, paper, and metal foil, and in particular, forms and supplies a plurality of supply ports to a die. The present invention relates to a die type coating apparatus and a coating method capable of obtaining a highly accurate and uniform film thickness accuracy in the width direction by adjusting the pressure or flow rate of the coating liquid supplied to the port for each supply port.

2. Description of the Related Art Conventionally, as a coating method for applying a coating solution to a long strip web using a die, there is slot die coating in which a coating solution is applied to a web using this slot die. Slot die coating is a coating method that has a liquid pool called a cavity inside the die, and the coating liquid is discharged from a narrow gap (slit) extending in the coating width direction leading from the liquid pool, and coating is performed on the web. is there.
On the other hand, in recent years, it has been required to increase the accuracy of an object to be applied to a die-type coating apparatus that performs such slot die coating, and in particular, a highly accurate and uniform film thickness accuracy in the width direction is required.

  Therefore, various thickness controls have been performed as a method for obtaining a uniform film thickness accuracy in the width direction with higher accuracy than before. Generally, the thickness control in the die coater is largely determined by the distribution performance resulting from the structure and shape of the die with respect to the target coating solution. Here, as the structure of the slot die, the coating liquid flows uniformly through cavities (liquid reservoirs) and slits (gap between parallel plates) processed with high precision on the order of microns, so that the coating liquid is evenly distributed and the uniformity is improved. For this reason, shape design by computer simulation, which takes time, has been actively performed.

However, the coating film actually applied on the web does not have the thickness accuracy as calculated, and often has a convex or concave trend with respect to the target value. In order to solve these problems, as an easy means, there is a method of adjusting the gap between the tip of the die and the coated substrate by cotter and bend. Further, as described in JP-A-8-216226, there is a method of adjusting the width of the slit with a die bolt. Furthermore, as an advanced means, many methods have been proposed such as a method of automatically adjusting the thickness while receiving a feedback signal from a thickness gauge immediately after coating (see Japanese Patent Application Laid-Open No. 2000-334359). Yes.
JP-A-8-216226 (page 4-6, FIG. 1) JP 2000-334359 A (page 4-6, FIG. 1)

  On the other hand, with the recent demands for high accuracy and high productivity, many methods that vary mechanically, including the above-mentioned Patent Document 1 and Patent Document 2, may cause quality concerns due to lack of repeatability. The control system maintenance method itself has become an issue. Therefore, it is required to establish a thickness control method that is more effective than ever and eliminate the need for die shape correction. In addition, when the final product appearance (e.g., winding shape) is a top priority, an operation to control the coating thickness to an arbitrary uneven trend is also required to cancel the substrate thickness variation as a raw material. ing.

  The present invention has been made to solve the above-described conventional problems, and is a die capable of obtaining a highly accurate and uniform width direction coating film thickness with high reproducibility without correcting the die shape. An object is to provide a method coating apparatus and a coating method.

In order to achieve the above object, a die type coating apparatus according to claim 1 of the present application includes a die for discharging a coating liquid with a predetermined coating width to a continuously running web, and a pump for feeding the coating liquid to the die. The coating liquid is provided at both the center position of the coating width with respect to the die and the positions spaced apart from the center position by a predetermined distance in the left-right direction of the coating width, and the coating liquid sent from the pump is supplied into the die. Supply pressure and the flow rate or flow rate of the coating solution supplied to the plurality of supply ports are supplied in the left-right direction with respect to the internal pressure of the die from 30 kPa to 300 kPa and from the supply port at the central position. to the extent that the mouth is higher pressure, adjusting the coating film above is applied to the web is adjusted to a predetermined pressure or a predetermined flow rate feedback control to each feed opening to a thickness trend that is arbitrarily set And having a stage, a.

According to a second aspect of the present invention, there is provided a die type coating apparatus according to the first aspect, wherein the die type coating apparatus according to the first aspect is provided with a conveying unit that conveys the coating liquid sent from the pump to the supply port, and the conveying unit. Branching means for branching the coating liquid into a path corresponding to the number of the supply ports, and the distance from the branching means to the supply port is equal .

The coating method according to claim 3 is a coating method in which a coating liquid is applied to a continuously running web using a die that discharges the coating liquid with a predetermined coating width. A supply port for supplying the inside of the die to the inside of the die is provided at both the center position of the coating width with respect to the die and a position separated from the center position by a predetermined distance in the left-right direction of the coating width. The pressure or flow rate of the coating liquid applied is applied to the web in such a range that the internal pressure of the die is 30 kPa to 300 kPa and the supply port in the left-right direction is higher than the supply port in the central position. It is characterized in that feedback control is performed so that the applied film has a thickness trend set arbitrarily, and the pressure is adjusted to a predetermined pressure or a predetermined flow rate for each supply port.

According to a fourth aspect of the present invention, there is provided the coating method according to the third aspect , wherein the coating liquid is supplied to the supply port in a transport path for transporting the coating liquid sent from the pump to the supply port. The distance from the branch point which branches to the route according to the number to the supply port is equal .

In the die type coating apparatus according to claim 1 having the above-described configuration, the supply ports supplied into the die are provided at a plurality of locations in the coating width direction with respect to the die, and the coating liquid supplied to the plurality of supply ports The pressure or flow rate is adjusted to a predetermined pressure or a predetermined flow rate for each supply port by performing feedback control so that the coating film applied to the web has an arbitrarily set thickness trend in a range where the die internal pressure becomes 30 kPa to 300 kPa. Therefore, the thickness of the coating film applied to the web can be adjusted with high accuracy, and as a result, the thickness of the coating film can be made uniform. Further, the conventional mechanical structure variable mechanism and control system are not required, and it can be fixed and stabilized with mechanical accuracy. Furthermore, the introduction and operation costs were reduced, the productivity was improved by stabilizing the quality, and the operator's management work was reduced.
In addition, since the plurality of supply ports are provided at the center position of the coating width and both positions separated by a predetermined distance from the center position in the left-right direction, without making the structure for supplying the coating liquid to the die complicated, In addition, the thickness in the coating width direction can be adjusted with high accuracy.

Further, in the die type coating apparatus according to claim 2, the conveying means for conveying the coating liquid delivered from the pump to the supply port is branched into a path according to the number of supply ports, and from the branch point to the supply port. Therefore, it is possible to adjust the flow rate and pressure of the coating liquid at each supply port with high accuracy.

Further, in the coating method according to claim 3 , the supply ports supplied into the die are provided at a plurality of locations in the coating width direction with respect to the die, and the pressure or flow rate of the coating solution supplied to the plurality of supply ports is set. In the range where the die internal pressure becomes 30 kPa to 300 kPa, the coating film applied to the web is feedback-controlled so that the thickness trend is arbitrarily set, and the application is performed by adjusting the supply pressure to a predetermined pressure or a predetermined flow rate for each supply port. Therefore, the thickness of the coating film applied to the web can be adjusted with high accuracy, and as a result, the thickness of the coating film can be made uniform. Further, the conventional mechanical structure variable mechanism and control system are not required, and it can be fixed and stabilized with mechanical accuracy.
In addition, since the supply port is provided at both the center position of the coating width and the left and right positions by a predetermined distance from the center position, the structure for supplying the coating liquid to the die is not complicated and the coating width direction Can be adjusted with high accuracy.

In the coating method according to claim 4 , the transport path for transporting the coating liquid sent from the pump to the supply port is branched into paths according to the number of supply ports, and the distance from the branch point to the supply port Therefore, the flow rate and pressure of the coating liquid at each supply port can be adjusted with high accuracy.

Hereinafter, based on the embodiment which materialized the die system application device and application method concerning the present invention, it explains in detail, referring to drawings.
First, the die type coating apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing a schematic configuration of a die type coating apparatus 1 according to the present embodiment, and FIG. 2 is a cross-sectional view of the die type coating apparatus 1 according to the present embodiment cut in the length direction of the die.

  As shown in FIG. 1, the die type coating apparatus 1 according to the present embodiment includes a die 2, a supply tank 3, a transport line 4, a metering pump 5, transport rollers 6 and 7, and a thickness measuring device 8. Basically composed.

  The die 2 is a slot die that forms a coating film 12 having a predetermined thickness by coating the coating liquid 11 on the surface of a web 10 such as a continuously running film, paper, or glass. Here, the die type coating apparatus 1 according to the present embodiment uses slot die coating that applies a coating solution to a web using a slot die. Slot die coating is a coating method that has a liquid pool called a cavity inside the die, and the coating liquid is discharged from a narrow gap (slit) extending in the coating width direction leading from the liquid pool, and coating is performed on the web. is there.

Below, the structure of the die | dye 2 which concerns on this embodiment is demonstrated in detail using FIG. FIG. 3 is a perspective view showing the die 2 according to the present embodiment. The die 2 according to the present embodiment basically includes a die body 15 and side plates 16 and 17 disposed on both sides of the die body 15.
Further, the die body 15 is formed by overlapping the blocks 18 and 19 with each other, and a slit 20 is formed by a gap between the blocks 18 and 19. Further, the side plates 16 and 17 regulate the application width W of the die 2 and hold the combination of the blocks 18 and 19.

  Furthermore, a lip surface 21 is formed on the die body 15 so as to face the web 10, and edge surfaces 28 and 29 are formed on the side plates 16 and 17 so as to face the web 10. Further, shims may be sandwiched between the die body 15 and the side plates 16 and 17, respectively. The shim is used for preventing leakage of the coating liquid, and the material is preferably an elastic body. Examples of shim materials include polymer films, adhesive tapes, and metals.

  The slit 20 forms a discharge port 22 with respect to the approximate center of the lip surface 21. The discharge port 22 discharges the coating liquid 11 with a coating width W, and the discharged coating liquid 11 is applied to the web 10 with a predetermined thickness.

  Further, as shown in FIG. 2, cavities (liquid reservoirs) 24 are formed in the blocks 18 and 19 along the width direction, and the cavities 24 are provided at the three application liquid supply ports 25 to 27 provided in the block 18. And communicated with the slit 20. The coating liquid supply ports 25 to 27 are connected to a coating liquid supply system constituted by the metering pump 5 and the like, and the measured coating liquid is supplied to the cavity 24 via the coating liquid supply ports 25 to 27. It is supplied by a metering pump 5. Further, the coating solution supplied to the cavity 24 is fed to the slit 20 and is discharged from the discharge port 22 of the slit 20 with the coating width W at a constant amount per unit time and with a uniform pressure in the width direction. The coating liquid supply port 26 is provided at the center position of the coating width W of the die 2, and the coating liquid supply port 25 is a predetermined distance from the coating liquid supply port 26 (for example, when the coating width W is 1500 mm). 500 mm) from the side plate 16. The coating liquid supply port 27 is formed from the side plate 17 by the same predetermined distance from the coating liquid supply port 26 (for example, 500 mm when the coating width W is 1500 mm). The coating liquid supply port 25 and the coating liquid supply port 27 at both ends may be provided on the side surfaces of the die 2 (that is, the side plates 16 and 17).

  On the other hand, the supply tank 3 is a tank for storing the coating solution 11, and the stored coating solution 11 is supplied to the die 2 by the metering pump 5 at a constant supply amount per unit time.

Further, the conveyance line 4 is a pipe connecting the supply tank 3 and the die 2, and the coating liquid 11 supplied from the supply tank 3 reaches the coating liquid supply ports 25 to 27 through the conveyance line 4. Here, in particular, in the die type coating apparatus 1 according to this embodiment, the transport line 4 is branched in three directions by a branch point 41. The first branch line 4A, which is one of the branched lines, is connected to the coating liquid supply port 25, the second branch line 4B is connected to the coating liquid supply port 26, and the third branch line 4C. Is connected to the coating liquid supply port 27. The lengths of the first branch line 4A to the third branch line 4C are all equal.
Further, in the transport line 4, automatic adjustment valves 42 and 43 for adjusting the flow rate of the coating liquid 11 in the first branch line 4A to the third branch line 4C, and the coating flowing in the first branch line 4A to the third branch line 4C. Pressure detectors 44 to 46 for detecting the pressure of the liquid 11 and flow rate detectors 47 to 49 for detecting the flow rate of the coating liquid 11 flowing in the first branch line 4A to the third branch line 4C are provided.

  The metering pump 5 is a supply means for supplying the coating liquid 11 stored in the supply tank 3 to the transport line 4 at a constant predetermined amount per unit time.

  The transport rollers 6 and 7 are transport means for transporting the web 10 in a predetermined direction at a predetermined speed set in advance. Here, as shown in FIG. 2, the transport roller 6 is disposed to face the die 2, and forms a gap at a predetermined interval with the lip surface 21.

  The thickness measuring device 8 is a sensor that detects the thickness of the coating film 12 applied to the web 10 in the width direction of the web 10 using infrared rays, radiation, an optical interferometer, or the like.

  Furthermore, the die type coating apparatus 1 is provided with a control device 51 for controlling the thickness measuring device 8, automatic adjustment valves 42 and 43, pressure detectors 44 to 46 and flow rate detectors 47 to 49. And the control apparatus 51 adjusts the opening degree of the automatic adjustment valves 42 and 43 according to the program set beforehand. Thereby, the inlet pressure or flow rate of each coating liquid supply port 25 to 27 can be adjusted. The control device 51 is additionally provided with the thickness of the coating film 12 detected by the thickness measuring device 8 and the pressure and flow rate of the coating liquid 11 detected by the pressure detectors 44 to 46 and the flow rate detectors 47 to 49. It is displayed on a monitor (not shown).

  Next, the application | coating process of the coating liquid 11 to the web 10 in the die | dye system coating apparatus 1 comprised as mentioned above is demonstrated. First, the application liquid 11 measured at a flow rate corresponding to the target thickness setting by the metering pump 5 connected to the level-controlled supply tank 3 is automatically adjusted valves 42 and 43, pressure detectors 44 to 46, and a flow rate detector 47. The liquid is fed to the coating liquid supply ports 25 to 27 through -49. The coating liquid 11 supplied from the coating liquid supply ports 25 to 27 to the inside of the die 2 is applied to the target substrate from the discharge port 22 while passing through the cavity 24 and the slit 20.

Next, the thickness shape in the web width direction of the coating film 12 formed on the web 10 by the coating process will be described with reference to FIG. FIG. 4 is a cross-sectional view of the coating film 12 formed on the web 10 cut in the width direction.
Here, in the coating process in which the coating solution 11 is applied to the web 10 using the die 2, the coating solution is supplied even if the first branch line 4A to the third branch line 4C are connected to each other by the same length. Just before the ports 25 to 27, a slight inlet pressure or flow rate difference is generated. Accordingly, every time the coating conditions are changed, the coating film 12 is uniform, or the central portion is high and both ends are low, or the central portion is low and both ends are high, so that the coating thickness d varies, and a stable coating film is obtained. Can't get 12.
The thickness trend at this time is reflected in this pressure and flow rate state. Conversely, if the pressure and flow rate are manipulated with high accuracy, an arbitrary thickness trend can be obtained. At this time, it is possible to configure them as an electric circuit using the automatic adjustment valves 42 and 43 and the thickness measuring device 8 that detects the thickness immediately after coating.

  Below, the thickness control operation | movement in the die-type coating device 1 is demonstrated. As a control pattern of the die type coating apparatus 1, pressure or flow rate is arbitrarily set while visually observing the thickness trend with a monitor or the like, and electric signals from the pressure detectors 44 to 46 and the flow rate detectors 47 to 49 are automatically adjusted. There is a method of obtaining a target thickness trend by feeding back to 42 and 43. Furthermore, the electrical signals from the thickness measuring device 8, the pressure detectors 44 to 46, and the flow rate detectors 47 to 49 are simultaneously processed so as to obtain a thickness trend that is arbitrarily set by programming a pattern for each application condition. However, there is a method of obtaining a target thickness trend by fully automatic control that feeds back to the automatic adjustment valves 42 and 43.

  Next, when the thickness control is performed with respect to the relationship between the supply port pressure of each of the coating liquid supply ports 25 to 27 adjusted by the automatic adjustment valves 42 and 43 and the thickness shape of the formed coating film 12 in the web width direction. The evaluation results of the coating film 12 formed on the web 10 will be described in comparison with the case where the thickness control was not performed.

<Application conditions>
As a coating condition, the die 2 having a coating width W of 1500 mm was used, and the arrangement of the coating liquid supply ports 25 to 27 was set to positions of 250 mm, 750 mm, and 1250 mm from one end of the die 2.
As the coating solution 11, an acrylic pressure-sensitive adhesive having a density of 0.9, a solid content of 30%, an apparent viscosity of 2000 mPa / 20 ° C., and a surface tension of 28 mN / m was used.
The line speed was 20 to 150 m / min, and the thickness after drying was 20 μm.
Furthermore, the automatic adjustment valves 42 and 43, the pressure detectors 44 to 46, and the thickness measuring device 8 consider the physical properties of the coating liquid, such as density, solid content concentration, viscosity, solvent type, and coating application range, and have high resolution. A commercially available product that can output an electrical signal was selected. They were controlled by connecting them to an electrical circuit that they made. The pressure detectors 44 to 46 in this example were measured using a diaphragm type pressure detector VNF manufactured by VALCOM.
Moreover, since the thickness measuring apparatus 8 affects not only the coating solution but also the base material to be coated, it needs to be examined in advance. In general, infrared rays, radiation, an optical interferometer, or the like is used, and any of them may be used as long as the target thickness accuracy can be examined. As the thickness measuring device 8 in this example, an infrared absorption type non-contact thickness measuring device IR-M manufactured by Chino Corporation was used. The coating thickness was measured by converting the coating thickness from a calibration curve between the thickness of the organic component and the infrared absorption spectrum.

  Here, FIG. 5 shows the control result of the supply port pressure of each of the coating liquid supply ports 25 to 27 when coating is performed in a total of three patterns when the thickness control is performed under the above coating conditions. It is a figure. FIG. 6 is a view showing the thickness shape of the coating film 12 formed on the web 10.

<Evaluation>
As shown in FIG. 6, it has been confirmed that the thickness trend is made uniform or controlled to an arbitrary unevenness by the control according to the present invention.
That is, without performing thickness control, the supply port pressure of the left coating solution supply port 25 is 100 kPa, the supply port pressure of the central coating solution supply port 26 is 70 kPa, and the supply port pressure of the right coating solution supply port 27 is 100 kPa. When the coating was performed, both ends of the coating film 12 in the width direction were about 3 μm thick from the vicinity of the center, resulting in a concave shape.
Further, without performing thickness control, the supply port pressure of the left coating solution supply port 25 is 80 kPa, the supply port pressure of the central coating solution supply port 26 is 90 kPa, and the supply port pressure of the right coating solution supply port 27 is 80 kPa. When the coating was performed, the vicinity of the center in the width direction of the coating film 12 was thicker by about 2 μm than both ends, resulting in a convex shape.
On the other hand, as a result of the thickness control, the supply port pressure of the left coating solution supply port 25 is 100 kPa, the supply port pressure of the central coating solution supply port 26 is 80 kPa, and the supply port pressure of the right coating solution supply port 27 is 100 kPa. As a result, there was almost no difference in thickness between the center in the width direction and both ends, and a uniform coating thickness could be obtained.

  Subsequently, the thickness control was performed on the relationship between the die internal pressure, which is the pressure of the coating solution 11 inside the die, and the thickness shape in the web width direction of the formed coating film 12 based on FIGS. The evaluation results of the coating film 12 formed on the web 10 will be described in comparison with the case where the thickness control was not performed.

<Application conditions>
As the coating conditions, the die 2 having a coating width W of 1500 mm was used, and the coating liquid supply ports 25 to 27 were arranged at positions 250 mm, 750 mm, and 1250 mm from one end of the die 2.
As the coating solution 11, an acrylic pressure-sensitive adhesive having a density of 0.9, a solid content of 30%, an apparent viscosity of 2000 mPa / 20 ° C., and a surface tension of 28 mN / m was used.
The line speed was 20 to 150 m / min, and the thickness after drying was 20 μm.

Here, FIG. 7 shows the thickness of the coating film 12 formed on the web 10 when coating is performed in a total of two patterns when the internal pressure of the die is 10 kPa and thickness control is performed under the above coating conditions. It is the figure which showed the shape.
Further, FIG. 8 shows the thickness shape of the coating film 12 formed on the web 10 when coating is performed in a total of two patterns when the die internal pressure is 30 kPa and thickness control is performed under the above coating conditions. FIG.
Further, FIG. 9 shows the thickness shape of the coating film 12 formed on the web 10 when coating is performed in a total of two patterns when the die internal pressure is 100 kPa and when the thickness is controlled under the above coating conditions. FIG.
FIG. 10 shows the thickness shape of the coating film 12 formed on the web 10 when coating is performed in a total of two patterns when the thickness control is performed under the above coating conditions with the die internal pressure being 300 kPa. FIG.
Moreover, FIG. 11 shows the thickness shape of the coating film 12 formed on the web 10 when coating is performed in a total of two patterns when the thickness control is performed under the above coating conditions with the die internal pressure being 500 kPa. FIG.

<Evaluation>
As shown in FIGS. 7 to 11, it was confirmed that the thickness trend was made uniform or controlled to an arbitrary unevenness by changing the die internal pressure. When the die internal pressure is 10 to 500 kPa, a more uniform thickness shape can be obtained by controlling the thickness. In particular, when the die internal pressure is 30 to 300 kPa, the difference in thickness between the center and the both ends of the coating film 12 in the width direction is reduced, and the most uniform surface of the coating film 12 when the die internal pressure is 100 kPa. Could get.

  On the other hand, FIG. 12 is a diagram showing the state of the time-dependent pressure inside the die. The die internal pressure is largely determined by the slot clearance setting, but it was also found that the control range is limited by this pressure region, and 10 to 500 kPa was found to be the applicable range. In particular, under high pressure, pressure fluctuation becomes noise, making control difficult. Desirably, if it performed at 30-300 kPa, it stabilized more. In addition, high accuracy was achieved by realizing mechanical fixation, and automatic control by programming was able to obtain repeated stability. It also covered design defects.

As described above in detail, in the die system coating apparatus 1 and the coating method according to the present embodiment, the coating liquid supply ports 25 to 27 for supplying the coating liquid 11 to the inside of the die 2 are arranged in the coating width direction with respect to the die 2. Since the pressure or flow rate of the coating solution supplied to the coating solution supply ports 25 to 27 is adjusted to a predetermined pressure or a predetermined flow rate for each supply port, the coating film 12 applied to the web 10 is provided in three places in total. The thickness in the coating width direction can be adjusted with high accuracy, and as a result, the thickness of the coating film 12 can be made uniform. Further, the conventional mechanical structure variable mechanism and control system are not required, and it can be fixed and stabilized with mechanical accuracy. Furthermore, even if there is a defect in the shape design of the die 2, correction can be made unnecessary by pressure or flow rate control. Therefore, the introduction and operation costs can be reduced, the productivity can be improved by stabilizing the quality, and the management work of the operator can be reduced.
In addition, since the coating liquid supply ports 25 to 27 are provided at a total of three positions, that is, a central position of the coating width and both positions separated by a predetermined distance from the central position in the left-right direction, the structure for supplying the coating liquid to the die is complicated. The thickness in the coating width direction can be set with high accuracy based on the pressure or flow rate of the coating liquid without using a simple configuration.
Further, the conveyance line 4 that conveys the coating liquid supply ports 25 to 27 sent from the metering pump 5 to the supply port is branched into a path according to the number of supply ports, and the coating liquid supply port 25 from the branch point 41. Since the distances up to 27 are equal, the flow rate and pressure of the coating liquid 11 at the coating liquid supply ports 25 to 27 can be adjusted with high accuracy.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the supply port for supplying the coating liquid 11 to the cavity 24 is provided at a total of three locations with respect to the side surface of the die 2 in the configuration of the die 2, but the number of supply ports is four or more. Also good.

It is a perspective view which shows schematic structure of the die-type coating device which concerns on this embodiment. It is sectional drawing which cut | disconnected the die-type coating device which concerns on this embodiment in the length direction of die | dye. It is the perspective view which showed the die | dye which concerns on this embodiment. It is sectional drawing which cut | disconnected the coating film formed on the web in the width direction. It is the figure which showed the control result of the supply port pressure of each coating liquid supply port with the case where it does not carry out when thickness control is performed. It is the figure which showed the thickness shape of the coating film formed in the web with and without performing thickness control. It is the figure which showed the thickness shape of the coating film formed in the web at the time of apply | coating by setting die internal pressure to 10 kPa. It is the figure which showed the thickness shape of the coating film formed in the web at the time of apply | coating by setting die internal pressure as 30 kPa. It is the figure which showed the thickness shape of the coating film formed in the web at the time of performing application | coating by making die | dye internal pressure into 100 kPa. It is the figure which showed the thickness shape of the coating film formed in the web at the time of apply | coating by setting die | dye internal pressure to 300 kPa. It is the figure which showed the thickness shape of the coating film formed in the web at the time of performing application | coating by making die internal pressure 500kPa. It is the figure which showed the state of the time-dependent pressure inside die | dye.

DESCRIPTION OF SYMBOLS 1 Die system coating apparatus 2 Die 4 Conveyance line 4A 1st branch line 4B 2nd branch line 4C 3rd branch line 10 Web 11 Coating liquid 12 Coating film 25-27 Coating liquid supply port 41 Branch point 42, 43 Automatic adjustment valve 51 Control device

Claims (4)

A die that discharges a coating liquid at a predetermined coating width on a continuously running web;
A pump for delivering the coating liquid to the die;
A supply that is provided at both the center position of the coating width with respect to the die and a position that is a predetermined distance away from the center position in the left-right direction of the coating width and that supplies the coating liquid sent from the pump into the die. Mouth,
The pressure or flow rate of the coating liquid supplied to the plurality of supply ports is set such that the internal pressure of the die is 30 kPa to 300 kPa and the supply port in the left-right direction is higher than the supply port at the center position. And an adjusting means for adjusting the pressure to a predetermined pressure or a predetermined flow rate for each supply port by performing feedback control so that the coating film applied to the web has an arbitrarily set thickness trend. Die type coating device. Transport means for transporting the coating liquid delivered from the pump to the supply port;
A branching unit that is provided in the transport unit and branches the coating liquid into a path according to the number of the supply ports,
The die coating apparatus according to claim 1 , wherein the distance from the branching unit to the supply port is equal. In the application method of applying the discharged application liquid to the continuously running web, using a die that discharges the application liquid with a predetermined application width,
A supply port for supplying the coating liquid fed from the pump into the die is provided at the center position of the coating width with respect to the die and at both positions separated from the center position by a predetermined distance in the left-right direction of the coating width , The pressure or flow rate of the coating liquid supplied to the supply port is a range in which the internal pressure of the die is 30 kPa to 300 kPa and the supply port in the left-right direction is higher than the supply port at the center position. Then, feedback control is performed so that the coating film applied to the web has a thickness trend that is arbitrarily set, and a predetermined pressure or a predetermined flow rate is adjusted for each supply port. The distance from the branch point where the coating liquid is branched into a path according to the number of the supply ports in the transport path for transporting the coating liquid sent from the pump to the supply port is the same length. The coating method according to claim 3 .

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