JP2017087169A - Coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to increase a circulation amount of a coating liquid.SOLUTION: A coating device comprises a coating unit 2, and a liquid feed route 4 and liquid return route 5 for circulating a coating liquid between the coating unit and a tank which is so located below the coating unit as to be separated from the coating unit. A coating chamber 22 of the coating unit 2 has plural exhaust ports 23b which communicate the liquid return route 5 with a liquid reservoir part above an inlet port 23a. The liquid return route 5 has plural branch paths 5b and one main path 5a, and at least a part of the main path 5a is provided with an expansion part 53 in which a volume of a flow channel is expanded.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a coating apparatus for coating a coating liquid on a sheet-like substrate that is continuously conveyed using a sealed coating unit in which a gravure roll and a coating chamber are integrated. In particular, the present invention relates to a structure of a path for collecting a coating liquid from a coating unit into a tank.

  On the outer peripheral surface of the gravure roll, a coating region composed of a large number of cells (concave portions) is formed in order to stably attach the coating liquid to be transferred to the base material. In order to supply the coating liquid to the coating region, a liquid reservoir for storing the coating liquid is formed.

  In order to stably supply the coating liquid from the tank that stores a large amount of the coating liquid to the liquid reservoir, the coating liquid is transferred between the tank and the liquid reservoir via the liquid feeding path and the liquid return path. It is circulating. In many cases, outlets through which the coating liquid flows out from the liquid reservoir to the liquid return path are provided at a plurality of locations in the width direction of the coating unit, and therefore, collecting pipes may be used for the liquid return path.

  For example, Patent Document 1 discloses a coating apparatus in which a liquid reservoir is divided into two chambers, and a liquid supply path and a liquid return path are provided for each chamber. The liquid return path of each chamber is composed of a T-shaped collective pipe whose lower end is inserted into the tank, and the upper end of the bifurcated collective pipe has two flows provided at both ends of the coating chamber. Connected to the exit.

JP 2012-239976 A

  In this type of coating apparatus, since air is brought into the liquid reservoir by the rotating gravure roll, there is a problem that air bubbles are mixed into the coating liquid in the liquid reservoir and uneven coating occurs. Increasing the circulation rate of the coating liquid facilitates the discharge of bubbles from the liquid reservoir, so increasing the circulation rate of the coating liquid is an effective means to solve the problem, but the closed-type coating liquid is used. In the case of the construction unit, it is not easy to increase the circulation amount of the coating liquid.

  The reason will be specifically described. In other words, the coating unit is generally disposed at a high position of 1 m or more on the floor where replacement, adjustment, maintenance, check, and the like are easily performed. On the other hand, the tank is generally disposed at a low position such as on the floor surface where the work such as replacement or replenishment of the coating liquid is performed, and such a work is easily performed.

  And if the internal pressure of a liquid reservoir part raises more than atmospheric pressure, supply of the coating liquid to a gravure roll will become unstable easily, and a coating liquid will leak from the clearance gap between a gravure roll and a coating chamber. Further, when the liquid reservoir has a negative pressure, air is drawn and bubbles are generated. For this reason, the liquid pressure in the liquid reservoir is normally maintained at a substantially normal pressure.

  Therefore, like the above-described coating apparatus of Patent Document 1, the transfer of the coating liquid from the tank to the liquid reservoir is generally performed by pumping such as a pump, and the liquid reservoir to the tank. The recovery of the coating liquid is performed by the natural fall of the coating liquid overflowing from the liquid reservoir that is open to the atmosphere. In Patent Document 1, a communication portion communicating with the outside is formed at the upper portion of the collecting pipe, and the liquid reservoir is opened to the atmosphere through the communicating portion. Usually, the lower end portion of the collecting pipe is communicated with the outside. The liquid reservoir is open to the atmosphere.

  Therefore, when the supply amount of the coating liquid to the liquid reservoir is increased in order to increase the circulation amount of the coating liquid, the amount of the coating liquid overflowing from the liquid reservoir is also increased accordingly. As a result, when the amount of the overflowing coating liquid exceeds the allowable amount of the collecting pipe, the liquid pressure in the liquid reservoir becomes unstable and the coating accuracy decreases.

  In the case of a collective pipe, the flow of the coating liquid stagnate because the coating liquid merges and collides with the flow at the collective part of the pipe. In particular, the effect is great when the viscosity of the coating solution is high and there are many bubbles. Therefore, if the supply amount of the coating liquid to the liquid reservoir is increased, liquid clogging may occur at the collecting portion, and the liquid pressure in the liquid reservoir may become unstable.

  As shown in FIG. 1, the tank 100 is usually disposed at a location away from the coating unit 101 so as not to interfere with the check operation of the coating unit 101. Therefore, the collective piping is often composed of a hose 102 that is easy to handle.

  In that case, since the hose 102 is hung in the air between the coating unit 101 and the tank 100, the middle of the hose 102 is bent and liquid clogging is likely to occur. When liquid clogging occurs in the middle of the hose 102, a siphon phenomenon occurs, the liquid reservoir becomes negative pressure, and a large amount of bubbles are mixed into the coating liquid.

  For this reason, it is difficult to increase the circulation rate of the coating liquid with a sealed coating unit, and the supply amount of the coating liquid is such that the amount of the coating liquid overflowing from the liquid reservoir is that of the collecting pipe. It had to be suppressed by a method such as reducing it from the set amount so as to be less than the allowable amount. Specifically, liquid clogging does not occur in the collecting pipe, and air freely enters and exits the liquid reservoir through the lower end of the collecting pipe, so that the air release state of the liquid reservoir is stably maintained. The supply amount of the coating liquid had to be adjusted, which was an obstacle to increasing the circulation amount of the coating liquid.

  Accordingly, an object of the present invention is to provide a coating apparatus that can suppress coating unevenness due to mixing of bubbles by improving the circulation rate of the coating liquid while ensuring good workability.

  The present invention provides a coating unit that applies a coating liquid to a sheet-like substrate that is continuously conveyed, a tank that is located below the coating unit and stores the coating liquid, and the coating The present invention relates to a coating apparatus including a liquid feeding path and a liquid return path for circulating the coating liquid between a unit and the tank.

  The coating unit is provided between a gravure roll that sends the coating liquid to the substrate, a coating chamber that is attached in parallel to a side of the gravure roll, and the gravure roll and the coating chamber. And a liquid reservoir for storing the coating liquid.

  The coating chamber has an inlet for communicating the liquid feeding path with the liquid reservoir, and a plurality of outlets for communicating the liquid return path with the liquid reservoir above the inlet. ing. The liquid return path includes a plurality of branch paths connected to the discharge port, and a single main path that extends toward the tank below, with each of the branch paths gathering at an upper end portion. Yes.

  Then, the coating liquid is supplied from the tank to the liquid reservoir through the liquid supply path, and the coating liquid overflowing from the liquid reservoir is recovered to the tank through the liquid return path. In addition, at least a part of the main path is provided with an expanded portion in which the volume of the flow path is expanded as compared with the liquid feeding path.

  That is, according to this coating apparatus, of the return path for guiding the coating liquid overflowing from the liquid reservoir to the tank, a plurality of branch paths are gathered and one main path extending toward the lower tank. At least a part is provided with an expanded portion in which the volume of the flow channel is expanded more than the liquid feeding path.

  Therefore, even if the coating liquid flows into the main path from the plurality of branch paths, the flow can be temporarily buffered by the expansion portion, and thus the occurrence of liquid clogging can be suppressed. Since an air layer can be secured in the extended portion, it is easy to maintain the air release state of the liquid reservoir. Thereby, the circulation amount of the coating liquid can be increased. Since only one main path extends toward the lower tank, it does not interfere with the check operation of the coating unit, and good workability can be ensured.

  For example, the main path may be formed of a hose, and the extension portion may be provided on the entire main path.

  Then, even if the circulation amount of the coating liquid is increased, the coating liquid can be transferred with a margin while ensuring the air flow path. Since the diameter becomes large and the hose is difficult to bend and bend, it is possible to effectively suppress the occurrence of liquid clogging in the middle of the hose and the negative pressure in the liquid reservoir. Because it is a hose, it is flexible and easy to handle.

  Particularly in this case, it is preferable to set the inner diameter of the main path in a range of 1.5 to 3 times the inner diameter of the liquid feeding path.

  Further, the extension part is configured by a buffer tank opened to the atmosphere installed in the middle of the main path, and the buffer tank is disposed below the coating unit and above the tank. Also good.

  Then, since the main path can be divided in the middle of the height difference between the coating chamber and the tank, the main path is shortened and the occurrence of liquid clogging can be suppressed. Even if liquid clogging occurs, the difference in height is small, so that a large negative pressure does not occur in the liquid reservoir even if a siphon phenomenon occurs. Since the air is released near the liquid reservoir, the internal pressure of the liquid reservoir is stabilized. Therefore, the circulation amount of the coating liquid can be increased.

  In this case, it is preferable that the buffer tank is disposed at a position close to one end of the coating unit and not overlapping the coating unit.

  By doing so, it is possible to prevent the buffer tank from being contaminated by the coating liquid dripping from the coating unit.

  When the tank is located on the opposite side of the gravure roll to which the coating chamber is attached, the buffer tank is directed from the position below the coating chamber toward the tank. It is preferable to provide it so as to extend substantially horizontally.

  Then, even if the tank is far away from the coating chamber, each divided main path can be shortened, so even if a hose is used for the main path, drooping can be effectively prevented and occurrence of liquid clogging is suppressed. it can.

  It is preferable that an inclination adjusting mechanism for adjusting the inclination angle of the buffer tank is attached to the buffer tank.

  If it does so, it can adjust so that the coating liquid inside a buffer tank may be discharged | emitted smoothly according to an installation place and the quality of a coating liquid, and it is excellent in convenience.

  According to the coating apparatus of the present invention, since the circulation amount of the coating liquid can be increased while ensuring good workability, coating unevenness due to mixing of bubbles can be effectively suppressed.

It is a schematic side view which shows the conventional coating apparatus. It is a schematic side view which shows the coating apparatus of 1st Embodiment. It is a schematic perspective view which shows the part of the coating unit of the coating device of 1st Embodiment. It is a schematic sectional drawing of the coating unit of the coating apparatus of 1st Embodiment. It is a schematic side view which shows the coating apparatus of 2nd Embodiment. It is a schematic back view which shows the coating apparatus of 2nd Embodiment. It is a schematic sectional drawing of the coating unit of the coating apparatus of 2nd Embodiment. It is the schematic which shows the principal part of the coating apparatus of the other system which can apply this invention. It is the schematic which shows the principal part of the coating apparatus of the other system which can apply this invention. It is the schematic which shows the principal part of the coating apparatus of the other system which can apply this invention. It is the schematic which shows the principal part of the coating apparatus of the other system which can apply this invention. It is the schematic which shows the principal part of the coating apparatus of the other system which can apply this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

<First Embodiment>
2 to 4 show a first embodiment in which the present invention is applied to a gravure kiss reverse type coating apparatus 1A. The coating apparatus 1A includes a coating unit 2, a tank 3, a liquid feeding path 4, a liquid returning path 5, and the like. It is comprised so that a coating liquid can be apply | coated continuously.

  The coating apparatus 1A is installed in a predetermined part of the coating system together with a drying apparatus and the like. In the case of this coating apparatus 1A, the base material W is transported in the vertical direction from bottom to top. The coating unit 2 is installed. In addition, the base material W is a sheet-like member having a flexible and long band shape made of synthetic resin, metal, or the like, and is usually conveyed by a roll-to-roll method.

(Coating unit)
As shown in detail in FIGS. 3 and 4, the coating unit 2 includes a gravure roll 21 and a coating chamber 22. As shown in FIG. 2, work such as replacement of the gravure roll 21, adjustment of the coating chamber 22, maintenance thereof, and check of the coating state is performed. It is easily placed at a position of 1m or more on the floor.

  The gravure roll 21 is a columnar member that is longer than the width of the substrate W, and is rotatable about a rotation axis J extending in the width direction of the substrate W in a substantially horizontal state by a support member (not shown). It is supported. In the case of this coating apparatus 1 </ b> A, the gravure roll 21 is disposed so as to be pressed against the base material W that is conveyed upward while floating while being pulled.

  The gravure roll 21 is controlled to rotate at a rotation speed that is linked to the conveyance speed of the substrate W. Specifically, the peripheral speed of the gravure roll 21 is controlled to coincide with the transport speed of the substrate W, or the peripheral speed is controlled to increase or decrease with respect to the transport speed of the substrate W. The rotation direction of the gravure roll 21 is set so as to rotate in the direction opposite to the conveyance direction of the substrate W at the contact position with the substrate W in the case of the coating apparatus 1A (reverse method).

  On the outer peripheral surface of the gravure roll 21, a coating region 21a provided with a large number of cells (dents) in a predetermined pattern such as a lattice or a diagonal line is formed. The gravure roll 21 rotates in a state where the coating region 21 a is in contact with the substrate W, and the substrate W is applied by transferring the coating liquid adhering to the coating region 21 a to the substrate W. The coating chamber 22 is attached to the side of the gravure roll 21 in order to supply the coating liquid to the coating region 21a.

  The coating chamber 22 has a rectangular column shape in appearance, and is integrated with the gravure roll 21 in a state of being arranged in parallel with the gravure roll 21 except for maintenance. The coating chamber 22 includes a chamber case 23, a pair of side covers 24, 24, a doctor blade 25, a seal blade 26, and the like.

  Specifically, the chamber case 23 is made of an elongated member having a U-shaped cross section with one side surface opened. A side cover 24 is fixed to each end portion of the chamber case 23, and both ends of the chamber case 23 are closed by the side covers 24 and 24. Each side cover 24 is provided with an arc-shaped seal portion that can be brought into close contact with the outer peripheral surface of the gravure roll 21, and each side cover 24 is in contact with the outer peripheral surface of the gravure roll 21. The position has been adjusted.

  The doctor blade 25 is an elongated blade-like metal member having a blade edge formed on one long side portion, and the other long side portion is bolted to a protruding end on the upper side of the chamber case 23. Thereby, the cutting edge side of the doctor blade 25 protrudes downward, and the position is adjusted so that the tip thereof is in contact with the outer peripheral surface of the gravure roll 21.

  The seal blade 26 is a synthetic resin member having the same shape as the doctor blade 25, and is bolted to the lower projecting end portion of the chamber case 23. The cutting edge side of the seal blade 26 protrudes obliquely upward, and the position thereof is adjusted so that the tip thereof is in contact with the outer peripheral surface of the gravure roll 21. As described above, the positions of the side covers 24, 24, the doctor blade 25, and the seal blade 26 are adjusted so as to be in contact with the gravure roll 21, whereby the coating between the gravure roll 21 and the coating chamber 22 is performed. A substantially sealed space (liquid reservoir 27) that enables liquid storage is formed.

  In order to circulate and supply the coating liquid to the liquid reservoir 27, an inlet 23a and an outlet 23b are formed on the back surface of the chamber case 23. There is one intake port 23 a, and the intake port 23 a is disposed at a substantially central portion in the lateral width direction of the chamber case 23. The intake port 23 a is formed in the lower part of the chamber case 23 and communicates with the lower part of the liquid reservoir 27.

  There are two discharge ports 23b, which are arranged at both ends of the chamber case 23 in the width direction so that the coating liquid flows smoothly in the width direction inside the liquid reservoir 27. These intake ports 23 a and 23 a are formed in the upper part of the chamber case 23 and communicate with the upper part of the liquid reservoir 27.

(tank)
The tank 3 is a container for storing a large amount of coating liquid, and is installed on the floor where such a work can be easily performed because operations such as replacement and replenishment of the coating liquid are performed. Furthermore, since it is necessary to secure a space for performing a check operation or the like around the coating unit 2, the coating unit 2 is disposed at a position laterally away from the coating unit 2 so as not to interfere with these operations. . The tank 3 may be movable by being mounted on a carriage.

  The liquid feed path 4 and the liquid return path 5 are installed between the tank 3 and the coating unit 2, and the coating liquid stored in the tank 3 is supplied to the liquid reservoir 27 while being circulated therethrough. It has come to be.

  The liquid feeding path 4 is composed of one liquid feeding pipe made of a steel pipe or a hose having a uniform inner diameter. The lower end of the liquid feeding pipe 4 is connected to the discharge port of the pump 30 attached to the upper part of the tank 3, and the upper end of the liquid feeding pipe 4 is provided on the back surface of the chamber case 23 and communicates with the inlet 23a. It is connected to the connecting steel pipe 41.

  A suction pipe is connected to the suction port of the pump 30, and the suction pipe is inserted in a suspended state into a partition tube provided inside the tank 3 with the lower part opened. The coating liquid enters the inside of the partition tube from the bottom, and the coating liquid is sucked into the pump 30 through the suction pipe. In addition, since a coating liquid is pumped in the liquid feeding path 4, the routing route of the liquid feeding path 4 can be set arbitrarily.

  The liquid return path 5 is composed of a collection pipe, and is composed of one main path 5a and two branch paths 5b and 5b branched in a T shape from the upper end of the main path 5a via the collection portion.

  Specifically, each branch path 5 b is configured by an L-shaped steel pipe 51. Each L-shaped steel pipe 51 has a short short pipe part 51a and a long long pipe part 51b extending perpendicularly to the short pipe part 51a. Each short pipe portion 51a is attached to the back surface of the chamber case 23 so as to communicate with the discharge port 23b, and each long pipe portion 51b extends along the chamber case 23 so that the opening ends thereof face each other with a gap. It extends. Each short pipe part 51a and each long pipe part 51b are arranged substantially horizontally.

  The gathering part is composed of a T-shaped steel pipe 52. The T-shaped steel pipe 52 is composed of a main pipe part 52a and a sub pipe part 52b that protrudes in a T shape perpendicular to the center of the main pipe part 52a, and the open end of the sub pipe part 52b in a direction away from the chamber case 23. The open ends of the long pipe portions 51b are connected to both open ends of the main pipe portion 52a.

  The main path 5a is composed of a single hose extending from the coating unit 2 toward the tank 3 below, and its lower end is inserted into the tank 3, and its upper end is the open end of the sub pipe portion 52b. It is connected to the. The lower end of the hose 5a is arranged in an air layer above the liquid level in the tank 3 so that air can always enter and exit.

  At the time of coating, the coating liquid is stored in the tank 3, and the coating liquid is supplied to the liquid reservoir 27 through the liquid feeding pipe 4, the connecting steel pipe 41, and the intake port 23a by being pumped by the pump 30. . Thereby, the inside of the liquid reservoir 27 is filled with the coating liquid, and when the outer peripheral surface of the rotating gravure roll 21 passes through the liquid reservoir 27, the coating liquid adheres to the coating region 21a. Excess coating liquid adhering to the coating region 21 a is scraped off by the doctor blade 25, and the coating liquid adjusted to a certain amount is transferred to the substrate W.

  The liquid reservoir 27 is opened to the atmosphere via the liquid return path 5, and excess coating liquid overflows from the liquid reservoir 27 and flows out from the discharge port 23 b and is collected in the tank 3 through the liquid return path 5. It has become so.

  When the outer peripheral surface of the gravure roll 21 enters the liquid reservoir 27, air is brought into the liquid reservoir 27, and bubbles are mixed into the coating liquid. Air bubbles mixed in the coating liquid cause coating unevenness, so that coating accuracy is lowered. Therefore, in this coating apparatus 1A, the volume of the flow path of the T-shaped steel pipe 52 and the hose 5a is set to the liquid feeding pipe 4 and the L-shaped steel pipe 51 so that the circulation amount of the coating liquid can be increased to facilitate the discharge of bubbles. The volume of the flow path is expanded (expansion portion 53).

  Specifically, the inner diameter of each L-shaped steel pipe 51 is the same as the inner diameter of the liquid feeding pipe 4, whereas the inner diameters of the T-shaped steel pipe 52 and the hose 5a are the inner diameters of the liquid feeding pipe 4 and the L-shaped steel pipe 51. Is bigger than. The inner diameters of the L-shaped steel pipes 51 may be larger than the inner diameters of the liquid feeding pipe 4 and the L-shaped steel pipe 51 in the same manner as the inner diameters of the T-shaped steel pipe 52 and the hose 5a.

  The coating liquid overflowing the liquid reservoir 27 and flowing out into the L-shaped steel pipes 51 merges in the T-shaped steel pipe 52 that is the collecting part and collides with the flow, but the volume of the collecting part is expanded. Therefore, clogging is less likely to occur, and even if the circulation amount of the coating liquid is increased, the air flow path can be secured stably and the liquid pressure in the liquid reservoir 27 can be kept stable. .

  Further, since the volume of the hose 5a is expanded, the coating liquid can be transferred with a margin while securing the air flow path even if the circulation amount of the coating liquid is increased. Since the diameter is increased and the hose 5a is difficult to sag and bend, it is possible to effectively suppress the clogging of the liquid in the middle of the hose 5a and the negative pressure in the liquid reservoir 27. The hose 5a is flexible and easy to handle. Therefore, the circulation amount of the coating liquid can be increased while ensuring good workability. As a result, coating unevenness due to mixing of bubbles can be suppressed, and coating accuracy can be improved.

  As shown in FIG. 4, in particular, the inner diameter L1 of the T-shaped steel pipe 52 and the hose 5a is preferably set in a range of 1.5 to 3 times the inner diameter L2 of the liquid feeding pipe 4 and the L-shaped steel pipe 51. If the inner diameter of the hose 5a or the like is smaller than 1.5 times the inner diameter of the liquid feeding pipe 4 or the like, liquid clogging may occur when the circulating amount of the coating liquid varies and increases. Further, if the inner diameter of the hose 5a or the like is larger than three times the inner diameter of the liquid feeding pipe 4 or the like, the member cost becomes high, and it becomes difficult to handle due to a decrease in flexibility and an increase in weight, so workability is impaired. . On the other hand, if the inner diameter of the hose 5a or the like is set in a range of 1.5 to 3 times the inner diameter of the liquid feeding pipe 4 or the like, the coating liquid does not cause clogging while ensuring good workability. The circulation amount of can be increased.

  The upper ends of the inner surfaces of the T-shaped steel pipe 52 and the upper end of the hose 5a connected thereto are preferably positioned above the upper end of the liquid reservoir 27. Then, even if the liquid reservoir 27 is filled with the coating liquid, an air layer is formed on the upper side of the upper ends of the T-shaped steel pipe 52 and the hose 5a connected thereto, so that the liquid reservoir 27 can be stably maintained in an open state.

  Furthermore, it is preferable that the center C inside the T-shaped steel pipe 52 and the hose 5 a connected thereto is positioned above the upper end of the liquid reservoir 27. If it does so, the circulation amount of a coating liquid can be increased, maintaining the liquid reservoir part 27 in moderate air release state. Further, the lower end inside the T-shaped steel pipe 52 and the hose 5 a connected thereto may be positioned above the upper end of the liquid reservoir 27. By doing so, it is possible to increase the circulation amount of the coating liquid while maintaining the liquid reservoir 27 in an open state with the liquid reservoir 27 being always filled.

Second Embodiment
5 to 7 show a second embodiment in which the present invention is applied to a gravure coating type coating apparatus 1B. As with the coating apparatus 1A of the first embodiment, the coating apparatus 1B includes a coating unit 2, a tank 3, a liquid feeding path 4, a liquid return path 5, and the like. The coating liquid is continuously applied to the sheet-like substrate W that is continuously conveyed.

  In the coating apparatus 1B of the present embodiment, unlike the coating apparatus 1A of the first embodiment, the liquid reservoir 27 is divided into two chambers, and the liquid supply path 4 and the liquid return path 5 are provided for each of these chambers. Yes (double chamber type). The expansion unit 53 is provided by installing a buffer tank 75 in each liquid return path 5. In addition, about the member which 1st Embodiment and description overlap, the description is abbreviate | omitted by using the same code | symbol for convenience.

(Coating unit)
As shown in FIG. 5, the coating unit 2 of the coating apparatus 1 </ b> B is also arranged at a height of 1 m or more on the floor at a position away from the tank 3 in the lateral direction. However, in the case of this coating apparatus 1B, the gravure roll 21 is disposed such that the base material W conveyed in a V shape by the pressure-bonding roll 6 is pressed against the gravure roll 21 from above. The contact position is set to rotate in the same direction as the transport direction of the substrate W.

  Thereby, compared with 1st Embodiment, the coating chamber 22 is attached to the reverse side of the gravure roll 21, As a result, the tank 3 is the side of the gravure roll 21 to which the coating chamber 22 is attached. It is located far away from the other side.

  As shown in FIG. 7, the liquid reservoir 27 of the coating unit 2 is partitioned into a lower first liquid reservoir 61 and an upper second liquid reservoir 62 by an inner plate 60 made of synthetic resin. ing. The first liquid reservoir 61 is provided with one first intake port 63 and two first discharge ports 64, 64, and the second liquid reservoir portion 62 has one second intake port 65 and two Second discharge ports 66 and 66 are provided.

  As shown in FIG. 6, the first intake 63 is arranged at a lower portion in the vertical width direction at a substantially central portion in the horizontal width direction on the back surface of the chamber case 23, and the second intake 65 is connected to the chamber case 23. It is arranged at an intermediate portion in the vertical width direction at a substantially central portion in the horizontal width direction on the back surface. Each first discharge port 64 is disposed at a portion between the first intake port 63 and the second intake port 65 in the vertical width direction at both ends in the horizontal width direction on the back surface of the chamber case 23. Each of the second discharge ports 66 is disposed at both ends in the lateral width direction on the upper surface of the chamber case 23.

  The first intake port 63 communicates with the lower part of the first liquid reservoir 61, and each first outlet 64 communicates with the upper part of the first liquid reservoir 61. Similarly, the second intake port 65 communicates with the lower part of the second liquid reservoir 62, and each second outlet 66 communicates with the upper part of the second liquid reservoir 62.

  The first inlet 63 and the second inlet 65 are connected to a first liquid feeding pipe 67 and a second liquid feeding pipe 68 each made of a steel pipe or hose having a uniform inner diameter. The lower ends of the first liquid supply pipe 67 and the second liquid supply pipe 68 are connected to a pump 30 attached to the tank 3 via a branch joint 69. A pump may be provided for each of the first liquid feeding pipe 67 and the second liquid feeding pipe 68, and each may be an independent liquid feeding path.

  A first branch path 71 and a second branch path 72 are connected to each of the first discharge port 64 and the second discharge port 66. Each of the first branch path 71 and the second branch path 72 is configured by an L-shaped steel pipe 51 having the same inner diameter as the liquid feeding pipe 4 and is connected by a T-shaped steel pipe 52 as in the first embodiment. ing. However, unlike the first embodiment, the inner diameter of the T-shaped steel pipe 52 of the coating apparatus 1 </ b> B is the same as the inner diameter of the liquid feeding pipe 4 as with each L-shaped steel pipe 51.

  A first hose 73 constituting the main path 5 a of the first liquid reservoir 61 is connected to the first branch path 71 via the T-shaped steel pipe 52, and the T-shaped steel pipe 52 is connected to the second branch path 72. The 2nd hose 74 which comprises the main path | route 5a of the 2nd liquid storage part 62 is connected through this. The inner diameters of the first hose 73 and the second hose 74 are the same as the inner diameter of the liquid feeding pipe 4. Unlike the first embodiment, each main path 5a of the first liquid reservoir 61 and the second liquid reservoir 62 is configured by a buffer tank 75 and a shared hose 76, respectively, of the first hose 73 and the second hose 74. Has been.

  The buffer tank 75 is composed of a horizontally long box-shaped container having an open upper surface. As shown in FIG. 5, the buffer tank 75 is positioned below the coating unit 2 and above the tank 3, and from the position below the coating chamber 22 across the gravure roll 21 toward the tank 3. It is installed to extend horizontally. Further, as shown in FIG. 6, the buffer tank 75 is disposed at a position close to one end portion of the coating unit 2 and does not overlap with the coating unit 2.

  A portion of the upper surface of the buffer tank 75 located below the coating chamber 22 is provided with a released receiving port 75a, and the other portion is covered with a removable lid 75b. The interior of the buffer tank 75 is always open to the atmosphere through the receiving port 75a.

  The lower ends of the first hose 73 and the second hose 74 are introduced into the buffer tank 75 through the receiving port 75a, and the lower ends of the first hose 73 and the second hose 74 are always in and out of the air. The buffer tank 75 is disposed at a position where it is not immersed in the coating liquid.

  A drainage port 75c is provided at the lower part of the end of the buffer tank 75 close to the tank 3, and a common hose 76 is connected to the drainage port 75c. Unlike the hose 5a of the first embodiment, the lower end of the common hose 76 may be above the liquid level in the tank 3 or may be disposed in the liquid. The inner diameter of the common hose 76 is arbitrary, but is usually the same as the inner diameter of the liquid feeding pipe 4. Since the function is not restricted, the length of the common hose 76 can be arbitrarily set.

  The buffer tank 75 is installed on a support stand 78 attached to the frame 77 of the coating apparatus 1B. The buffer tank 75 is provided with a plurality of extendable jack bolts 79 (an example of an inclination adjusting mechanism), and is supported by a support base 78 via the jack bolts 79. That is, the buffer tank 75 can adjust the inclination angle by adjusting the height of each jack bolt 79, and can adjust so that the coating liquid inside flows smoothly toward the drain port 75c.

  In this coating apparatus 1B, the coating chamber 22 and the tank 3 are located far apart in the lateral direction. Therefore, if these are connected as they are with a hose, the hose easily sags and liquid clogging occurs. Moreover, since two hoses hang down around the work space, the work tends to be disturbed.

  On the other hand, in this coating apparatus 1B, the hose is divided by relaying with a buffer tank 75 that is located in the middle of the height difference between the lower end of the coating chamber 22 and the upper end of the tank 3 and extends in the lateral direction. The lower hose is shared by one common hose 76.

  Thereby, since the length of the 1st hose 73 and the 2nd hose 74 becomes short and the drooping can be prevented effectively, generation | occurrence | production of liquid clogging can be suppressed. Even if the liquid clogging occurs, the difference in height is small, so that a large negative pressure does not occur in the first liquid reservoir 61 or the second liquid reservoir 62 due to the siphon phenomenon. Since these can be opened to the atmosphere near the first liquid reservoir 61 and the second liquid reservoir 62, the internal pressure of the first liquid reservoir 61 and the second liquid reservoir 62 is stabilized. Therefore, the circulation amount of the coating liquid can be increased.

  Since the coating liquid discharged from the first liquid reservoir 61 and the coating liquid discharged from the second liquid reservoir 62 are mixed in the buffer tank 75 opened to the atmosphere, bubbles are generated in these coating liquids. Even if a large amount is mixed, bubbles can be reduced by the buffer tank 75. Thereby, it is possible to prevent a large amount of bubbles from being brought into the tank 3.

  During coating, part of the coating liquid leaks out due to the structure of the coating unit 2. On the other hand, in this coating apparatus 1B, the buffer tank 75 is arrange | positioned in the position which does not overlap with the coating unit 2 up and down. Therefore, the coating liquid dripping from the coating unit 2 does not adhere to the buffer tank 75, and the buffer tank 75 can be prevented from being stained with the coating liquid.

  The buffer tank 75 is arranged at a position close to one end of the coating unit 2 so as to be orthogonal to the coating unit 2 and extend along the frame 77. Therefore, the buffer tank 75 does not interfere with the check operation and the workability is not impaired. In particular, in the case of this coating apparatus 1B, the first hose 73 and the second hose 74 share a portion located near the work space with a single common hose 76, so that the work is more obstructive. It becomes difficult to become.

  In addition, the coating apparatus concerning this invention is not limited to embodiment mentioned above, The other various structure is included.

  For example, as long as a hermetic coating unit is used, the method of the coating apparatus is not selected in the present invention. As shown in FIG. 8A, not only a double chamber type but also a general gravure coating type (direct gravure type) coating apparatus having one liquid reservoir, or a gravure roll 21 as shown in FIG. The present invention can also be applied to a gravure coating type (direct reverse type) coating apparatus that is set so as to rotate in the direction opposite to the conveying direction of the substrate W at the contact position.

  Further, as shown in FIG. 8C, the present invention is also applied to a coating apparatus that employs a gravure offset method in which the gravure roll 21 transfers the coating liquid to the substrate W via the transfer roll 80 (may be two or more). Is possible. Furthermore, the present invention is also applicable to a coating apparatus that employs a kiss reverse method as shown in FIGS. 8D and 8E.

  Further, the inner diameters of the T-shaped steel pipe 52, the first hose 73, and the second hose 74 of the second embodiment may be increased in the same manner as in the first embodiment.

  The seal blade 26 is not limited to resin, but may be made of other materials, for example, stainless steel or rubber. Moreover, you may use what gave the ceramic coat | court to the metal. The doctor blade 25 is not limited to metal but may be made of other materials, for example, resin or rubber. Moreover, you may use what gave the ceramic coat | court to the metal.

1A, 1B Coating device 2 Coating unit 3 Tank 4 Liquid supply path (liquid supply piping)
5 Return path 5a Main path (hose)
5b Branch path 21 Gravure roll 22 Coating chamber 23a Inlet 23b Outlet 24 Side cover 25 Doctor blade 26 Seal blade 27 Liquid reservoir 30 Pump 51 L-shaped steel pipe 52 T-shaped steel pipe 53 Expansion section 60 Inner plate 61 First liquid reservoir Part 62 Second liquid reservoir 63 First inlet 64 First outlet 65 Second inlet 66 Second outlet 67 First liquid supply pipe 68 Second liquid supply pipe 71 First branch path 72 Second branch path 73 First hose 74 Second hose 75 Buffer tank 76 Common hose W Base material

Claims (7)

A coating unit for applying a coating liquid to a sheet-like substrate that is continuously conveyed;
A tank that is located below the coating unit and stores the coating liquid;
A liquid feed path and a liquid return path for circulating the coating liquid between the coating unit and the tank;
A coating apparatus comprising:
The coating unit is
A gravure roll for sending the coating liquid to the substrate;
A coating chamber attached in parallel to the side of the gravure roll;
A liquid reservoir provided between the gravure roll and the coating chamber, for storing the coating liquid;
Have
The coating chamber is
An intake for communicating the liquid supply path with the liquid reservoir;
A plurality of outlets for communicating the liquid return path with the liquid reservoir above the inlet;
Have
The return path is
A plurality of branch paths connected to the outlet;
Each of the branch paths gathers at the upper end, and one main path extending toward the tank below,
Have
The coating liquid is supplied from the tank to the liquid reservoir through the liquid supply path, and the coating liquid overflowing from the liquid reservoir is recovered to the tank through the liquid return path, A coating apparatus, wherein an extended portion in which a volume of a flow path is expanded as compared with the liquid feeding path is provided in at least a part of the main path. In the coating device according to claim 1,
A coating apparatus in which the main path is formed of a hose, and the extended portion is provided on the entire main path. In the coating device according to claim 2,
A coating apparatus in which an inner diameter of the main path is set in a range of 1.5 to 3 times an inner diameter of the liquid feeding path. In the coating device according to claim 1,
The extension part is composed of a buffer tank opened to the atmosphere installed in the middle of the main path,
A coating apparatus in which the buffer tank is disposed below the coating unit and above the tank. In the coating device according to claim 4,
A coating apparatus in which the buffer tank is disposed at a position close to one end of the coating unit and does not overlap with the coating unit. In the coating device according to claim 5,
The tank is located on the opposite side of the gravure roll to which the coating chamber is attached,
The said buffer tank is a coating device provided so that it may extend substantially horizontally toward the said tank from the position under the said coating chamber. In the coating device according to claim 6,
A coating apparatus in which an inclination adjusting mechanism for adjusting an inclination angle of the buffer tank is attached to the buffer tank.

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