JP2014188449A - Intermittent coating apparatus and intermittent coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of a coated film by forming rising at the starting end and falling at the ending end of the coated film as abrupt respectively.SOLUTION: An intermittent coating apparatus comprises a coating head 7 which coats the surface of a sheet 4 with liquid 3 supplied from a supply tank 5, a supply valve 10 including a valve body 10a which opens and closes a coating passage 8a for supplying the liquid 3 from the supply tank 5 to the coating head 7, a first servo motor 11 which drives the valve body 10a, and a control device 12 which controls the first servo motor 11 so that the valve body 10a opens and closes the coating passage 8a intermittently. The control device 12 controls the valve body 10a so as to implement a first operation in which the valve body 10a is opened from the closing position for blocking the coating passage 8a to a fist opening position, a second operation in which the valve body 10a is opened to a second opening position that is larger than that of the first opening position with a slower speed than that of the first operation so as to keep constant the pressure for supplying the liquid 3 to the coating head 7 after the first operation, and a third operation in which the valve body 10a is closed form the second opening position to the closing position.

Description

  The present invention relates to an intermittent coating apparatus and an intermittent coating method for intermittently forming a coating film.

  2. Description of the Related Art A coating device for applying a liquid to a sheet that is continuously conveyed from a winding roll toward a winding roll is known. In this type of coating apparatus, there is an intermittent coating apparatus that repeatedly stops and restarts the supply of the liquid to be coated and repeatedly forms an uncoated area and a coated area (for example, Patent Documents 1 to 3).

  In the intermittent coating apparatus, it is required to make the film thickness of the coating film formed by intermittently applying the liquid uniform within the coating region of the coating film. In particular, in the area of the coating film starting from the uncoated area to the coated film starting point, it is a problem to form a steep rising edge without causing the coating film to swell. In addition, it is a problem to form a sharp trailing edge at the end of the coating film from the coating area to the end area of the coating film that becomes an uncoated area.

  That is, the intermittent coating apparatus is required to form a coating film such that the side walls at the beginning and end of the coating film are perpendicular to the coating surface.

JP 2001-38276 A (see FIG. 2) JP 2006-51407 A (see FIG. 2) JP 2011-88138 A (see FIG. 3)

  With respect to the intermittent application apparatus related to the present invention described above, the relationship between the operation of the supply valve and the coating film will be described with reference to the drawings.

  The figure for demonstrating the relationship between the operation | movement of a supply valve and a coating film in the intermittent application apparatus relevant to this invention in FIGS. Each of FIGS. 6 to 8 shows a change in the position of the valve body with time, a change in pressure of the liquid supplied to the coating head, and a change in film thickness with time. 6 to 8, the change in the position of the valve element of the supply valve is indicated by a solid line, and the change in the position of the valve element of the return valve is indicated by a broken line.

  In the intermittent coating apparatus related to the present invention, the stroke (movement amount) of the valve body of the supply valve is kept constant as shown in FIG. 6 except for the opening and closing operations at the beginning and end of coating. It was leaning. First, the stroke of the valve body of the supply valve is set to such a size that the end of the coating film is not disturbed and liquid dripping does not occur in the intermittent application non-application area. The larger the stroke of the valve body, the larger the negative pressure at the end of the coating film, so that the turbulence at the end of the coating film becomes smaller and no dripping occurs in the uncoated area.

  However, when the stroke is increased in order to eliminate the inconvenience at the end of the coating film, the action of liquid being pushed out from the supply valve is increased, and as shown in FIG. 7, a swell occurs immediately after the starting end of the coating film. End up.

  When the swell occurs at the beginning of the coating film, the intermittent coating apparatus related to the present invention, as shown in FIG. 8, has only to slow the opening speed of the supply valve in order to suppress the swell, I had to form a gentle rise. Therefore, as shown in FIG. 8, it is difficult to manufacture a coated product that is restricted with respect to the rising length L with respect to the conveyance direction of the sheet 4 at the starting end of the coating film.

  Patent Document 1 discloses a configuration for suppressing the swell at the starting end of the coating film when the supply valve is driven using an air cylinder. However, Patent Document 1 discloses a technique for suppressing the rising of the starting edge of the coating film when driven using an air cylinder, but it is considered to form the rising edge of the starting edge of the coating film sharply. Not.

  Patent Document 2 discloses a configuration in which a gap is provided between a valve body and a shaft that drives the valve body. With this configuration, the configuration described in Patent Document 2 improves the effect of preventing the swell of the coating film in the configuration of Patent Document 1. However, in the configuration described in Patent Document 2, as in Patent Document 1, it is not considered to form the leading edge of the coating film sharply.

  Patent Document 3 discloses a configuration having a valve body that is arbitrarily driven using a motor. In the configuration described in Patent Document 3, the coating film is formed so as to have a target film thickness by feeding back the measurement result of the shape of the formed coating film to the driving of the valve body. However, Patent Document 3 discloses a technique for correcting the local shape at the rising and falling of the coating film, but prevents the end of the coating film from being disturbed and dripping into the uncoated area. It is not considered to do.

  Therefore, in the configurations described in Patent Documents 1 to 3, it is difficult to form the rising and falling edges of the coating film steeply and to prevent the end of the coating film from being disturbed and dripping into the uncoated area. It was.

  Then, an object of this invention is to provide the intermittent application apparatus and intermittent application method which can solve the subject of the said related technique. An example of an object of the present invention is to provide an intermittent coating apparatus capable of forming the leading edge and the trailing edge of a coating film steeply and improving the quality of the coating film. is there.

  In order to achieve the above-described object, an intermittent application apparatus according to the present invention includes a supply unit that supplies paint, an application unit that applies the paint supplied from the supply unit along the surface of the material to be applied, and a supply unit. A supply valve having a valve body that opens and closes a flow path for supplying paint to the application section, a drive section that drives the valve body, and a control that controls the drive section so that the valve body opens and closes the flow path intermittently A section.

  The control unit performs a first operation on the valve body that opens from the closed position where the valve body closes the flow path to the first open position, and a first operation so as to maintain a constant pressure for supplying the coating material to the application unit after the first operation. A second operation for opening the valve body to a second opening position larger than the first opening position and a third operation for closing the valve body from the second opening position to the closing position at a speed slower than the first opening position. Control the disc.

Further, the intermittent application method according to the present invention is an application method for intermittently applying the paint supplied from the supply unit along the surface of the material to be applied.
The opening and closing operation of the valve body of the supply valve that opens and closes the flow path for supplying the coating material from the supply section to the application section is a first operation that opens the valve body from the closed position where the valve body closes the flow path to the first open position. After the first operation, the second operation of opening the valve body to a second opening position larger than the first opening position at a speed slower than the speed of the first operation so as to keep the pressure for supplying the coating material to the application unit constant. And a third operation for closing the valve body from the second open position to the closed position.

  According to the present invention, in the coating film to be applied intermittently, the rising edge at the start and the falling edge at the end of the coating film can be formed steeply and the quality of the coating film can be improved.

It is a schematic diagram which shows the intermittent application apparatus of embodiment. It is a schematic diagram for demonstrating the principal part in the intermittent application apparatus of embodiment. It is a figure for demonstrating the change of the position of the supply valve in embodiment. It is a figure for demonstrating the relationship between the opening / closing operation | movement of a supply valve in an embodiment, and a coating film. It is a figure for demonstrating the other example of the opening / closing operation | movement of a supply valve in embodiment. It is a figure for demonstrating the relationship between the operation | movement of a supply valve, and a coating film in the intermittent application apparatus relevant to this invention. It is a figure for demonstrating the relationship between the operation | movement of a supply valve, and a coating film in the intermittent application apparatus relevant to this invention. It is a figure for demonstrating the relationship between the operation | movement of a supply valve, and a coating film in the intermittent application apparatus relevant to this invention.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  The intermittent coating apparatus of the present embodiment is used to apply a liquid to the surface of a sheet as a material to be continuously conveyed, but is not limited to the flat surface of the sheet. It may be used to apply along a curved surface.

  In FIG. 1, the schematic diagram of the intermittent application apparatus of embodiment is shown. In FIG. 2, the schematic diagram of the principal part of the intermittent application apparatus of embodiment is shown.

  As shown in FIGS. 1 and 2, the intermittent application apparatus 1 according to the embodiment includes a supply tank 5 as a supply unit that supplies a liquid 3 that is a paint, and a pump 6 that supplies the liquid 3 from the supply tank 5. The liquid 3 supplied from the supply tank 5 is applied along the surface of the sheet 4 as the material to be applied, the application head 7 as an application unit, and the flow for supplying the paint from the supply tank 5 to the application head 7. A path 8, a supply valve 10 having a valve body 10 a that opens and closes the flow path 8, a first servo motor 11 as a drive unit that drives the valve body 10 a of the supply valve 10, and the valve body 10 a intermittently pass the flow path 8. And a control device 12 as a control unit for controlling the first servomotor 11 so as to open and close automatically.

  The flow path 8 provided in the intermittent coating apparatus 1 returns the liquid 3 supplied from the supply tank 5 to the coating head 7 and the liquid 3 supplied from the supply tank 5 to the supply tank 5. And a return flow path 8b.

  Further, the intermittent application device 1 of the embodiment is applied from the return valve 13 having the valve body 13a for opening and closing the return flow path 8b, the second servo motor 14 for driving the valve body 13a of the return valve 13, and the supply valve 10. An application pressure sensor 16 for detecting the pressure of the liquid 3 supplied to the head 7 (hereinafter referred to as application pressure) and the pressure of the liquid 3 supplied from the supply tank 5 (hereinafter referred to as supply pressure). And a supply pressure sensor 17 for detecting.

  Although not shown, the sheet 4 is supplied from a sheet supply roll and is continuously conveyed from the sheet supply roll toward the sheet take-up roll at a predetermined speed.

  Then, the control device 12 controls the first servo motor 11 to open the valve body 10a in the first stroke from the closed position where the valve body 10a of the supply valve 10 blocks the application flow path to the first open position. After the first operation, the valve is operated with a second stroke from the first opening position to a second opening position larger than the first opening position at a speed slower than the speed of the first operation so as to keep the application pressure constant. The opening / closing operation of the valve body 10a of the supply valve 10 is controlled so that the second operation of opening the body 10a and the third operation of closing the valve body 10a from the second open position to the closed position are performed.

  FIG. 3 is a diagram for explaining a change in the position of the valve body 10a of the supply valve 10. FIG. 3A shows a schematic diagram for explaining the position of the valve body 10a, and FIG. 3B shows a change in the position of the valve body 10a with time.

  As shown in FIG. 3A, in this embodiment, the open position of the valve body 10a is set with the position where the valve body 10a is closed as the reference position. Therefore, as shown in FIG. 3B, the valve body 10a is opened to a predetermined opening position with the passage of time.

  The pump 6 is disposed in the flow path 8 and is electrically connected to the control device 12.

  The coating head 7 is disposed at a position facing the surface of the sheet 4 conveyed at a predetermined speed, and intermittently ejects the liquid 3 onto the sheet 4.

  As shown in FIG. 2, the supply valve 10 includes a valve body 10a for opening and closing an application flow path 8a for supplying the liquid 3 to the application head 7, a valve seat 10b having an opening opened and closed by the valve body 10a, and a valve body. 10a and a cylinder 10c provided with a valve seat 10b.

  Similar to the supply valve 10, the return valve 13 includes a valve body 13a for opening and closing a return flow path 8b for returning the liquid 3 to the supply tank 5, a valve seat 13b having an opening opened and closed by the valve body 13a, and a valve body 13a. And a cylinder 13c provided with a valve seat 13b.

  The supply tank 5 is connected to a return flow path 8b branched from the flow path 8 for supplying the liquid 3 to the application head 7, and a part of the liquid 3 supplied from the supply tank 5 to the application head 7 is circulated. Yes.

  The first servo motor 11 is coupled to the supply valve 10 and is electrically connected to the control device 12. The second servo motor 14 is coupled to the return valve 13 and is electrically connected to the control device 12.

  As shown in FIG. 1, the application pressure sensor 16 is disposed in the application flow path 8 a between the supply valve 10 and the application head 7, and is electrically connected to the control device 12. The supply pressure sensor 17 is disposed in the return flow path 8 b between the supply tank 5 and the supply valve 10 and is electrically connected to the control device 12.

  The speed of the valve body 10a in the first operation for opening the supply valve 10 is set to be approximately the same as the speed of the valve body 10a in the third operation for closing the supply valve 10.

  The operation | movement which intermittently apply | coats to the sheet | seat 4 is demonstrated about the intermittent application apparatus 1 comprised as mentioned above. FIG. 4 shows the relationship between the opening / closing operation of the supply valve 10 and the coating film in the embodiment. In FIG. 4, a change in the position of the valve body 10a of the supply valve 10 is indicated by a solid line, and a change in the position of the valve body 13a of the return valve 13 is indicated by a broken line.

  First, as shown in FIG. 4, the intermittent application apparatus 1 opens the valve body 10a of the supply valve 10 in the first operation from the closed position to the first open position by a first stroke, thereby rising the starting end of the coating film. Is formed steeply. Subsequently, after the first operation, the second opening of the valve body 10a to the second opening position is performed at a speed slower than the speed of the valve body 10a in the first operation so that the application pressure is kept constant without fluctuation. By performing the operation, the film thickness of the coating film is kept constant.

  After the second operation, the trailing end of the coating film is sharply formed by performing the third operation of closing the valve body 10a with the second stroke from the second opening position to the closing position for closing the coating flow path 8a. . And after closing the valve body 10a and forming the non-application area | region in the sheet | seat 4, a coating film is intermittently applied to the sheet | seat 4 by performing the opening / closing operation | movement of the valve body 10a including the 1st, 2nd, and 3rd operation | movement mentioned above. Formed.

  As shown in FIG. 4, in synchronization with the opening / closing operation of the supply valve 10, the valve body 13 a of the return valve 13 performs an opening / closing operation opposite to the opening / closing operation of the supply valve 10. Further, the amount of movement of the valve body 13a in the operation of opening the return valve 13 is the same as the amount of movement of the valve body 13a in the operation of closing the return valve body 13, and after opening the valve body 13a, the valve body It is kept in a certain open position until 13a is closed.

  In the present embodiment, the first opening position of the valve body 10a is set to a position 1 mm from the reference position where the valve body 10a is closed, and the second opening position of the valve body 10a is a position 5 mm from the reference position. Is set to That is, in the present embodiment, the first opening position of the valve body 10a moved by the first operation is set to about 1/5 of the second opening position of the valve body 10a moved by the second operation. However, the present invention is not limited to this, and is set to an appropriate open position within a range in which no swell occurs at the starting end of the coating film.

  When the coating film is actually formed by the intermittent coating apparatus 1 of the embodiment, the valve body 10a is moved from the second open position in the second operation so that the trailing edge of the coating film can be sharply formed. Set the second stroke to close.

  Subsequently, a coating film is formed under the condition that the first stroke for opening the valve body 10a in the first operation and the second stroke for closing the valve body 10a in the second operation are set to be the same. Check the shape of the starting edge. Then, while confirming the shape of the starting end of the formed coating film, the first opening position for opening the valve body 10a is appropriately set while appropriately reducing the first stroke.

  At this time, the speed at which the valve body 10a is opened to the first opening position in the first stroke in the first operation and the speed at which the valve body 10a is closed from the second opening position in the second stroke in the second operation are set to be approximately the same. Therefore, an appropriate speed is set within a speed range in which the start and end of the coating film can be formed in an appropriate shape.

  As described above, in the second operation, in order to prevent an increase in the coating pressure, the valve body is moved from the first opening position to the second opening position using all of the steady coating time for forming the coating film with a constant film thickness. Opening is desirable. However, if it is possible to prevent the application pressure from increasing in the second operation, the second operation may be performed only during a part of the above-described steady application time, if necessary. That is, if it is possible to form the coating film with a constant film thickness, the controller 12 opens the valve body 10a that has been opened to the second opening position between the second operation and the third operation. Control may be performed so as to perform another operation for maintaining the position.

  As described above, according to the intermittent coating apparatus 1 of the embodiment, the start-up of the coating film starts by controlling the supply valve 10 so as to perform the opening / closing operation including the first, second, and third operations described above. In addition, it is possible to form each of the trailing edges sharply, and to prevent the coating film from being disturbed at the terminal end and from dripping into the uncoated region. As a result, according to the embodiment, the region where the film thickness fluctuates at the starting end of the coating film (rise length L with respect to the conveyance direction of the sheet 4) can be reduced, and the region where the coating film is formed is increased. The quality of the coating film can be improved.

  Thus, since the area | region where the film thickness in a coating film becomes constant by reducing the area | region where the film thickness of the edge part of a coating film becomes small, the quality of the product using the apply | coated sheet | seat 4 can be improved. it can. In addition, by reducing the area where the film thickness at the edge of the coating film fluctuates, it is possible to reduce the disposal of areas where the film thickness of the coating film is unstable and reduce the manufacturing cost of products using the coated sheet 4 can do.

  By the way, in the intermittent application apparatus 1 of the present embodiment, the rising edge of the coating film is sharply formed, but depending on the liquid forming the coating film and other coating conditions, there is a possibility that a dent may be formed at the coating film starting edge. is there. FIG. 5 shows another example of the opening / closing operation of the supply valve 10 in the embodiment. In FIG. 5, the change of the position of the valve body 10a of the supply valve 10 is shown by a solid line, and the change of the position of the valve body 13a of the return valve 13 is shown by a broken line.

  As shown in FIG. 5, when a dent is formed at the starting end of the coating film, the coating pressure is reduced for a time corresponding to the time when the dent is formed in the coating film. Therefore, in the time corresponding to the time for which the depression is formed in the coating film, it is possible to eliminate the formation of the depression by performing the opening speed of the valve body 10a in the second operation at a relatively high speed. become. Then, after the time corresponding to the time when the depression is formed, the coating pressure is kept constant by keeping the coating pressure constant by performing the operation of opening the valve body 10a in the second operation at a relatively slow speed. It can be formed with a film thickness.

  In other words, the control device 12 may perform the control by changing the second operation so that the speed slower than the speed of the first operation becomes smaller in steps, and the second operation controls the valve body 10a. You may open to a 2nd open position at several speeds.

  By controlling the second operation in this manner, it is possible to form the leading edge and the trailing edge of the coating film steeply, respectively, and improve the quality of the coating film as described above.

DESCRIPTION OF SYMBOLS 1 Intermittent application apparatus 3 Liquid 4 Sheet 5 Supply tank 7 Application head 8 Flow path 8a Application flow path 10 Supply valve 10a Valve element 11 First servo motor 12 Control apparatus

Claims (6)

A supply section for supplying paint;
An application unit that applies the paint supplied from the supply unit along the surface of the material to be applied; and
A supply valve having a valve body for opening and closing a flow path for supplying paint from the supply unit to the application unit;
A drive unit for driving the valve body;
A control unit that controls the drive unit so that the valve element intermittently opens and closes the flow path,
The controller is
A first action of opening the valve body from a closed position where the valve body closes the flow path to a first open position;
After the first operation, the valve body is moved to a second opening position larger than the first opening position at a speed slower than the speed of the first operation so as to keep the pressure for supplying the coating material to the application unit constant. A second action to open,
An intermittent application device that controls the valve body to perform a third operation of closing the valve body from the second open position to the closed position.   2. The intermittent coating apparatus according to claim 1, wherein the control unit performs the second operation by changing the speed that is slower than the speed of the first operation in a stepwise manner.   2. The intermittent control according to claim 1, wherein the control unit performs control so as to keep the valve body opened to the second opening position between the second operation and the third operation at the second opening position. Coating device. In the application method of intermittently applying the paint supplied from the supply unit along the surface of the material to be applied,
Opening and closing operation of a valve body of a supply valve that opens and closes a flow path for supplying paint from the supply unit to the application unit;
A first action of opening the valve body from a closed position where the valve body closes the flow path to a first open position;
After the first operation, the valve body is opened to a second opening position larger than the first opening position at a speed slower than the speed of the first operation so as to keep the pressure at which the coating material is supplied to the application unit constant. A second operation;
An intermittent application method in which control is performed to perform a third operation of closing the valve body from the second open position to the closed position.   The intermittent coating method according to claim 4, wherein the second operation is performed such that a speed slower than the speed of the first operation is changed stepwise.   5. The intermittent application method according to claim 4, wherein control is performed so that the valve body opened to the second release position is maintained at the second release position between the second action and the third action.

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