JP4077784B2 - Curtain coating method and curtain coating apparatus - Google Patents

Description

  The present invention relates to a curtain coating method and a curtain coating apparatus for dropping a curtain formed of a plurality of layers of liquid film and coating the surface of a traveling board with the plurality of layers of film.

  In the curtain coating method, a liquid film can be formed by a curtain discharge device, the liquid film can be freely dropped as a curtain, and the curtain can be collided on a traveling board to coat the film on the surface of the board. The end in the width direction of the free-falling curtain is regulated by the guide device, and the width of the curtain during the free-fall is maintained at a predetermined width. Without using the guide device, both ends of the curtain can be free ends. Patent Document 1 describes a curtain coating method in which a curtain is formed as a liquid film having a plurality of layers, and a plurality of layers are coated on the surface of a traveling plate. Yes.

  In the coating position on the plate, if the curtain width is equal to or smaller than the plate width, the thickness of the film coated on the surface of the plate tends to be thick at the end in the width direction, The film thickness uniformity may not be maintained. On the other hand, if the width of the curtain is made wider than the width of the plate at the coating portion on the plate, the thickness of the film coated on the plate can be made uniform in the width direction.

  When the width of the curtain is made wider than the width of the plate, the curtain portion located outside the both ends of the width of the plate will fall below the plate. About this falling curtain part, if a curtain is a liquid film of a single layer, it can collect | recover and it can reuse as a curtain liquid film raw material. However, when coating a plurality of layers of liquid film as described in Patent Document 1, the curtain is a liquid film of a plurality of layers even in the curtain portion that falls outside the both ends of the width of the plate. Becomes a mixture of two or more different compositions and cannot be reused as a curtain liquid film raw material.

  In the invention described in Patent Document 2, one of the plurality of liquid films constituting the curtain is larger than the width of the web (plate), and the other layer has a width that does not overflow the web. . Thus, since the liquid film overflowing from the edge of the web is a single layer, the overflowing composition can be collected and recycled into the liquid feed of the same composition layer. Here, a layer having a width larger than the width of the web and having the same width as the curtain width is called a wide layer, and a layer having a width that does not overflow the web is called a narrow layer.

Japanese Patent Publication No.49-24133 Japanese Patent Publication No.62-47075

  For example, in a method of curtain coating a multilayer coating film on a steel plate such as a strip steel, the steel plate is run and the curtain is dropped on the running steel plate surface to perform curtain coating. The traveling steel plate may meander in the width direction. In addition, the width of the curtain discharged from the curtain discharge device with a predetermined width varies in the process of dropping, and the curtain width at the coating site applied to the plate may vary.

  When applying the method described in Patent Document 2, the end of the narrow layer does not protrude from both ends of the plate so that the curtain portion falling from the outside of both ends of the plate is always a single layer. It is necessary to paint. On the other hand, the board which travels as described above meanders in the width direction, and the width of the narrow layer in the coating portion may also vary. Therefore, in order to prevent the end of the narrow layer from protruding from both ends of the plate, the width of the narrow layer is assumed to be the width of the plate, assuming the degree of meandering of the plate and the width variation of the narrow layer. It is necessary to set a narrower width. As a result, there are regions where the layer to be formed by the narrow layer is not applied at both ends of the plate. Since both end portions of the plate to which the narrow layer is not applied cannot be made good, it is necessary to trim and discard these portions after finishing the painting. As for the cut-off portion, the plate itself and the coating applied on the plate are wasted.

  The present invention relates to a curtain coating method in which a curtain made of a plurality of liquid films is dropped and a plurality of layers of films are coated on the surface of a traveling board, and the curtain portion falling from outside the both ends of the width of the board is maximized. An object of the present invention is to provide a curtain coating method and a curtain coating apparatus capable of minimizing the cut-off amount due to trimming of a plate while being utilized.

That is, the gist of the present invention is as follows.
(1) In a curtain coating method of dropping a curtain 10 made of a plurality of layers of liquid film and coating the surface of the traveling plate 11 with a plurality of layers of film, at least one of the liquid films constituting the falling curtain 10 The width of the curtain is narrower than the full width of the curtain, and the full width 32 of the curtain at the coating site is wider than the width 34 of the traveling plate. A curtain coating method, wherein the side and the end side of the plate are collected separately.
(2) A width 33 of a layer having a width narrower than the full width of the curtain (hereinafter referred to as “narrow layer”) is wider than the width 34 of the plate, and the width end portion side of the curtain 10 and the end portion of the plate The separation position 12 collected separately on the side is in the vicinity of the width end portion 24 of the narrow layer, the curtain coating method according to (1) above.
(3) The curtain coating according to (2) above, wherein the width direction position and the separation position 12 of the curtain discharge device 1 for discharging the curtain are adjusted according to the width direction shift position of the traveling plate 11. Overturning method.
(4) A curtain having a curtain discharge device 1 for discharging a plurality of liquid films and dropping the curtain 10 made of the discharged plurality of liquid films, and covering the surface of the traveling plate 11 with a plurality of layers of films. In the coating apparatus, the width of at least one layer of the liquid film constituting the falling curtain 10 can be narrower than the entire width of the curtain (hereinafter referred to as “narrow layer”), and the total curtain width 32 at the coating site. Can be made wider than the width 34 of the traveling plate, and the collecting apparatus 14 collects the curtain flowing down outside the both ends of the width of the plate separately on the width end side of the curtain and the end side of the plate. A curtain coating apparatus characterized by comprising:
(5) The collection device 14 includes a moving device 18 for moving in the curtain width direction the separation position 12 for collecting separately on the curtain width end side and the plate edge side. 4) Curtain coating apparatus.
(6) The curtain coating apparatus according to (4) or (5) above, further comprising a width detecting device that detects the position of the narrow end 24 of the narrow layer and the position of the end of the steel plate 11.
(7) The curtain coating device according to any one of (4) to (6), wherein the curtain discharge device 1 and the recovery device 14 are movable in the width direction of the traveling plate 11.
(8) The width 33 at the coating portion of the narrow layer is adjusted by adjusting the width 31 at the discharge portion of the narrow layer, according to any one of the above (1) to (3), Curtain coating method.
(9) The curtain coating apparatus 1 according to any one of the above (4) to (7), wherein the curtain discharge apparatus 1 includes an edge guide 6a for adjusting the width 31 at the discharge portion of the narrow layer.

  The present invention relates to a curtain coating method and a curtain coating apparatus for dropping a curtain 10 composed of a plurality of layers of liquid film and coating a plurality of layers of film on the surface of a traveling plate 11. In curtain coating, the total curtain width 32 at the coating site is wider than the width 34 of the traveling plate. Since both ends of the width of the curtain 10 are located outside the ends of the width of the plate, the thickness of the film coated on the plate 11 can be made uniform in the width direction.

  The width of at least one layer of the liquid film constituting the falling curtain 10 is narrower than the entire width of the curtain. This narrow layer is called a narrow layer. A layer having a width equal to the entire width of the curtain is called a wide layer. Thereby, it can be set as a single layer film | membrane about the part of the width | variety both ends among curtain full width.

  The present invention is further characterized in that curtains flowing down outside the width ends of the plate are separately collected on the width end side of the curtain and the end side of the plate. Of the curtains that flow down outside the width ends of the board, the single-layer film part at both ends of the curtain width can be collected separately from the inner part of the curtain. , It can be reused as a liquid feedstock for layers of the same composition. As a result, even if the multilayer film portion including the narrow film in the curtain is located outside the both ends of the width of the plate, the multilayer film portion flowing down outside the both ends of the width of the plate Since the single-layer film portion is collected separately, there is no problem in collecting and reusing the single-layer film portion.

  The present invention relates to a curtain coating method and a curtain coating apparatus in which a curtain composed of a plurality of layers of liquid film is dropped and coated with a plurality of layers of film on the surface of a traveling plate, and flows down outside both ends of the width of the plate. The curtains are collected separately at the curtain width end side and the plate end side. For this reason, even if the multilayer film portion of the curtain is positioned outside the both ends of the width of the plate, the single layer film portions at both ends of the curtain width can be recovered independently, There will be no hindrance to collection and reuse. As a result, the width of the multilayer film portion of the curtain can be made wider than the width of the plate, and the cut-off amount due to the trim of the plate can be minimized.

  In the present invention, as the curtain discharge device 1 for forming a liquid film, for example, the device shown in FIG. 1 can be used. The curtain discharge device 1 has two or more discharge slits 2. When a liquid is discharged from each discharge slit 2, the discharged liquid becomes a liquid film and flows down along the inclined surface of the curtain discharge device 1. The curtain discharge device 1 shown in FIG. 1 has three discharge slits (2a to 2c) from the first layer to the third layer. The liquid film discharged from the third-layer discharge slit 2c flows down to the position of the second-layer discharge slit 2b and forms a two-layer liquid film in contact with the liquid film discharged from the second-layer discharge slit 2b. The two-layer liquid film flows down to the first-layer discharge slit 2a and contacts the liquid film discharged from the first-layer discharge slit 2a to form a three-layer liquid film. The three-layer liquid film flows down along the inclined surface, leaves the inclined surface at the inclined end, and freely falls as the three-layer curtain 10.

  Below the curtain discharge device 1, a plate 11 is running as an object for curtain coating. The multi-layer curtain 10 dropped on the surface of the board adheres to the surface of the board while maintaining the multi-layer state, and a plurality of layers of films are coated on the surface of the board.

  In the present invention, the width of at least one layer of the liquid film constituting the falling curtain 10 is narrower than the full width of the curtain, and the full width 32 of the curtain at the coating site is wider than the width 34 of the traveling plate. . A layer having a width narrower than the full width of the curtain is called a narrow layer, and a layer having the same width as the full width of the curtain is called a wide layer. In the example of the curtain discharge device 1 shown in FIG. 1, the first layer constitutes a wide layer having the same width as the entire curtain width, and the second layer and the third layer constitute a narrow layer. Of the full width of the curtain, the outer portion in the width direction forms a single-layer curtain of only the first layer. This portion is referred to as an “outer single layer portion 36”. The central portion in the width direction forms a three-layer curtain from the first layer to the third layer. This portion is referred to as “inner multilayer portion 35”. The overall curtain width 32 (width of the wide layer) at the coating site is wider than the width 34 of the traveling board, and as a result, the curtains located at the outer portions at both ends of the board width are not coated on the board surface. It will flow down.

  The present invention is characterized in that the curtains flowing down outside the both ends of the width of the plate are separately collected on the width end side of the curtain and the end side of the plate. A portion collected on the side of the width end of the curtain is referred to as an “outer collection unit 41”. The portion collected on the end side of the plate is referred to as “inner collection portion 40”.

  First, a case where the width 33 of the narrow layer is wider than the width 34 of the plate will be described as a preferred embodiment. In this case, since the width of the inner multilayer portion 35 is wider than the width 34 of the plate, both sides of the inner multilayer portion 35 flow down from the outside of the width ends of the plate. All of the outer single layer portion 36 flows down from the outside of the width ends of the plate.

  When the curtain flowing down outside the both ends of the width of the plate is separately collected on the width end side of the curtain and the end side of the plate, the separation position 12 for collecting separately is the vicinity of the width end portion 24 of the narrow layer That is, it is set near the boundary between the inner multilayer portion 35 and the outer single layer portion 36. As a result, only the liquid in the outer single layer portion 36 is recovered in the outer recovery portion 41 on the width end portion side of the curtain, and all the liquid in the inner multilayer portion 35 is recovered in the inner recovery portion 40 on the end portion side of the plate. In the example of FIG. 1, the outer single layer portion 36 recovered by the outer recovery portion 41 is separated and recovered only in the liquid constituting the first layer, so that it can be reused again as the raw material of the first layer. Is possible. The separation position 12 is preferably near the boundary between the inner multilayer portion 35 and the outer single layer portion 36, taking into account the amount of variation in the width 31 of the narrow layer at the application position, and slightly on the outer single layer portion side. Thereby, the situation where the inner side multilayer part 35 mixes in the outer side collection | recovery part 41 can be avoided.

  In the inner collection section 40, the liquid in the inner multilayer portion 35 is collected, and the liquid from the first layer to the third layer is collected and collected in this portion, so that it is difficult to reuse as the raw material liquid. Therefore, when determining the width of the narrow layer, it is preferable to make the width of the narrow layer as close as possible to the width of the plate and reduce the amount of the inner multilayer portion 35 recovered by the inner recovery portion 40 as much as possible.

  In the present invention, the difference between the width 33 of the narrow layer and the width 34 of the plate at the coating site is preferably set to a value approximately equal to the sum of the plate meandering amount and the width variation assumed amount of the narrow layer. . As a result, even if the meandering of the plate occurs or the width of the narrow layer fluctuates, the layer coated on the surface of the plate can be a multilayer film in any part in the width direction, and at the same time the narrow width The width of the layer can be as close as possible to the width of the plate.

  In the present invention in which the width of the narrow layer is wider than the width of the plate, the meaning of providing the outer single layer portion 36 outside the narrow layer, that is, the inner multilayer portion 35 will be described.

  In order to make the thickness of the layer applied to the surface of the board uniform in the board width direction, it is necessary to make the total width 32 of the curtain at the coating site sufficiently wider than the width 34 of the board. It is preferable that both edges have a width of 100 mm or more. Therefore, if the curtain does not have the outer single layer portion 36 and the entire width of the curtain is a multilayer film, the amount of liquid that is a multilayer film portion that flows down outside the width ends of the plate and cannot be reused is large. Become. In contrast, according to the present invention, the curtain 10 has the outer single-layer portion 36, and the width of the curtain is sufficiently narrower than the width of the plate to ensure the uniformity of the coating film, while being narrow. The difference between the width 33 of the layer and the width 34 of the plate is made sufficiently small, and the amount of liquid that cannot be reused in the multilayer film portion that flows down outside the both ends of the width of the plate can be minimized. It becomes. Of course, the outer monolayer portion 36 is recovered alone and reused.

  The difference between the width 33 of the narrow layer and the width 34 of the plate at the coating site may be a value smaller than the sum of the amount of meandering amount of the plate and the amount of width variation of the narrow layer. In this case, when the meandering of the plate occurs or the width of the narrow layer fluctuates, the boundary between the inner multilayer portion and the outer single layer portion (the narrow layer end portion 24) falls within the width range of the plate. Since there is a possibility, it will be necessary to trim the edge of the plate slightly, but the amount of the inner multilayer portion 35 recovered by the inner recovery portion 40 can be further reduced.

  In the present invention, the width 33 of the narrow layer may be equal to the width 34 of the plate, or the width 33 of the narrow layer may be slightly narrower than the width 34 of the plate. Although the trim removal amount at the plate end portion is slightly increased, the amount of the inner multilayer portion 35 recovered by the inner recovery portion 40 can be further reduced. When coating is performed so that the end of the inner multilayer portion 35 does not protrude from both ends of the plate, the width 33 of the narrow layer is made smaller than the width 34 of the plate, and the width of the plate The difference between the width 34 and the width 33 of the narrow layer needs to be larger than a value equal to the sum of the estimated amount of meandering of the plate and the estimated width variation of the narrow layer. For this reason, the required amount of trim of the plate is also required to be approximately equal to the sum of the meandering amount of the plate per one side and the expected amount of width fluctuation of the narrow layer. The amount can be smaller than conventional values.

  As shown in FIG. 1, the recovery device 15 that separately collects the outer recovery portion 41 on the width end side of the curtain and the inner recovery portion 40 on the end portion side of the plate, The inner collection unit 40 can be collected by the collection pan 16. Alternatively, as shown in FIG. 2, the partition plate 17 is provided, the outer collection portion 41 is collected at the outer portion of the partition plate 17, and the inner collection portion 40 located at the inner portion of the partition plate 17 is collected by the collection pan 16. can do.

  In curtain coating, normally, the end of the curtain during free fall is regulated by the guide device 5. Although the position of the guide device 5 in the space may be fixed, a lower end free guide device 5 as shown in FIG. 1 may be used in order to form a stable and good free fall curtain. Such a guide device is composed of a guide chain 5a and a weight 5b attached to the tip of the guide chain 5a. A force to move vertically downward is exerted by the weight of the weight 5b, while the curtain 10 during free fall contracts in the width direction. The position of the guide device is determined at a position where the force to be worked works and the two forces are balanced. As a result, the width of the curtain 10 becomes a shape that becomes narrower as it goes downward during free fall. When the width of the liquid film is about 250 mm, the total curtain width 32 at the coating position may be about 20 mm smaller than the width of the liquid film at the ejection slit (curtain full width 30). Further, when the width of the liquid film in the discharge slit 2 of the discharge device is kept constant, the width of the curtain at the coating position varies depending on the type, physical properties, and flow rate of the liquid constituting the curtain. In this case, the width of the narrow layer at the coating position fluctuates, and the recovery amount of the inner recovery portion 40 that cannot be reused increases, or the trim amount of the plate needs to be increased. It becomes.

  In the present invention, it is preferable to adjust the width 33 of the narrow layer at the coating site by adjusting the width 31 of the narrow layer at the discharge site. This makes it possible to always keep the width 33 of the narrow layer in the coating portion constant. As shown in FIG. 3, if the curtain discharge device 1 has an edge guide 6a for adjusting the width 31 of the narrow layer at the discharge site, the width at the discharge site is adjusted by adjusting the position of the edge guide 6a. The width 31 of the layer can be adjusted, and the width 33 of the narrow layer at the coating site can be adjusted to be constant. The width of the narrow layer is adjusted before the start of curtain coating on the plate, and the width can be adjusted more precisely if it is performed while the plate is running. In FIG. 3A, the width 31 of the narrow layer at the discharge position is set wide, and in FIG. 3B, the width 31 of the narrow layer at the discharge position is set narrow.

  When adjusting the width of the narrow layer by the edge guide 6a, as shown in FIG. 4, it is preferable to use a width detection device that detects the width end position of the narrow layer and the end position of the steel plate. As the width detection device, for example, a device that simultaneously images the free-falling curtain 10 and the traveling plate 11 with an imaging device such as a CCD camera 21 can be used. When the illumination device 20 is arranged on the opposite side of the imaging device across the curtain 10 and light is irradiated from behind the curtain, the narrow film, that is, the inner multilayer portion 35 is thicker and the outer single layer portion 36 is thicker. Therefore, the brightness of the curtain 10 is different between the inner multilayer portion 35 and the outer single layer portion 36, and the end 24 of the narrow layer can be identified as the boundary between them. If the image processing device 22 performs image processing on an image captured by the imaging device, the position of the end 24 of the narrow layer can be recognized. Further, the end portion of the plate 11 can also be recognized by image processing. Based on the detection result of the width end position of the narrow layer and the end position of the steel plate detected by the width detecting device in this way, when the width of the narrow layer is too narrow, the position of the edge guide 6a is expanded to reduce the width. When the width of the layer is too wide, the position of the edge guide 6a can be narrowed to adjust the width of the narrow layer to an optimum width.

  As the detection means of the width detection device, in addition to the above method using the CCD camera 21, a method of measuring a relative position using a laser distance meter, a method of detecting a position by detecting infrared rays, or the like may be adopted. . Moreover, it is also possible to detect the separation positions collected separately on the curtain width end side and the plate end side using the imaging device of the width detection device.

  If the position of the free fall curtain is changed according to the meandering of the board in the width direction, and the free fall curtain is always located immediately above the board, the difference between the width of the board and the width of the narrow film is further reduced. can do. At this time, it is necessary to adjust the separation position of the recovery device simultaneously with the position adjustment of the free fall curtain. In a preferred embodiment of the present invention, as shown in FIG. 5, the width direction position and the separation position 12 of the curtain discharge device 1 that discharges the curtain are adjusted according to the width direction shift position of the traveling plate. The curtain discharge device 1 and the collection device 14 are movable in the width direction of the traveling plate, measure the width variation state of the plate, and set the curtain discharge device and the collection device in the width direction according to the measurement result. Move to. The moving means is preferably controlled using an actuator such as a stepping cylinder that has a high response speed and can accurately control the moving amount. Stepping cylinders (23a, 23b) are connected to the curtain discharge device 1 and the collection device 14 to control the movement of both.

  Regarding the movement of the curtain discharge device 1 and the collection device 14, the operator may move the positions of the curtain discharge device 1 and the collection device 14 in the horizontal direction while observing the position in the width direction of the plate 11 with a television camera. Alternatively, the position in the width direction of the plate 11 may be detected using a photo sensor or the like, and the positions of the curtain discharge device 1 and the collection device 14 may be moved according to the amount of movement. Alternatively, based on the detection result by the width detection device, the positions of the curtain discharge device 1 and the collection device 14 are moved so that the relationship between the position of the width end portion of the plate and the position of the narrow film end portion is always constant. It's also good.

  The preferred conditions for applying the curtain coating method of the present invention when multilayer coating with a polymer coating on the surface of a continuous strip steel will be described.

  The meandering amount of the steel sheet at the curtain coating position can be suppressed to within 1 mm as a result of devising to reduce the meandering amount. Further, when a film comprising a wide film and a narrow film was applied on a steel plate and the degree of blurring at the narrow film end was measured, it was found that the blur at the narrow film end was within 1 mm. It was. At this time, the steel sheet surface is coated with a multilayer film for the entire width in the width direction. As a result, the trim required amount of the steel sheet is set to zero, and the inner multilayer part collected by the inner recovery part is minimized. The end position may be set to a position as close as possible to the end position of the steel plate at a position 2 mm or more away from the end position of the steel plate. As for the separation position of the recovery device, if it is set as close to the boundary as possible at a position 1 mm or more away from the boundary between the narrow layer and the wide layer to the wide layer side, the liquid collected by the outer recovery unit It is possible to maximize the recovery amount of the outer single layer portion that is not mixed with the liquid of the multilayer portion and is recovered by the outer recovery portion.

  The curtain coating method of the present invention was applied when multilayer coating of a polymer coating was performed on the surface of a continuous steel strip having a width of 1000 mm. The film simultaneously coated by the curtain coating method of the present invention is a multilayer film having a maximum of three layers, and the coated film thickness of the coated product is 10 to 60 μm including films other than the simultaneously coated film.

  Curtain coating was performed using the curtain coating apparatus shown in FIG. The full width of the curtain, that is, the width of the wide film is 1200 mm, the running speed of the steel plate when performing curtain coating is 50 to 70 m / min, and the flow rate of each film to be curtain coated is 10 to 70 ml / m / s. . When the amount of meandering in the width direction of the steel sheet was measured, it was 1 mm. Moreover, when the fluctuation amount of the narrow film edge part was measured, it was 1 mm. Therefore, the width 33 of the narrow film at the coating position was adjusted to the steel plate width (1000 mm) +3 mm.

  As shown in FIG. 6B, the collection device 14 is provided with a collection pot 15 for collecting the outer collection unit and a collection pan 16 for collecting the inner collection unit. By adjusting the position of the recovery pot 15 by the stepping cylinder 19, the separation position 12 between the outer recovery part and the inner recovery part was set to a position 3 mm outward from the end 24 of the narrow layer at the coating position.

  Before the start of painting, as shown in FIG. 6A, the shutter 28 and the intermediate pan 27 are disposed between the curtain discharge device 1 and the steel plate 11, and all the curtains are collected and discarded by the intermediate pan 27. When painting continuous strip steel, the painting specifications may change in the middle of the coil. By providing the shutter 28 under the intermediate pan 27, it is possible to prevent the paint from being scattered on the adjacent steel strip of different specifications, and to prevent the paint from being scattered to the slitting coil. After the welding point of the strip steel has passed, the intermediate pan 27 and the shutter 28 are moved, and coating on the steel plate (plate 11) is started.

  At the start of painting, the end position of the narrow layer and the end position of the wide layer are not stable, so the entire amount of the curtain that flows down is recovered in the recovery pan 16 without being disposed in the recovery pot 15 and discarded. When the coating starts stably, the recovery pot is moved from the left and right to a predetermined position by the operation of the stepping cylinder 19, and the outer single layer portion is recovered by the recovery pot 15. The position of the collection pot was adjusted by the operator using a TV camera. As a result, after the curtain was stabilized, most of the outer single layer portion could be recovered without mixing the narrow layer.

  In Example 1, a partition plate 17 as shown in FIG. 2 was used in place of the collection pot 15. As with the use of the collection pot 15 in Example 1, most of the outer single layer portion could be collected. The position of the partition plate 17 was captured by a video camera, and the operator moved it from the left and right using the stepping cylinder 23c to adjust the position.

  In the curtain coating of Example 1, when the amount of meandering of the steel sheet at the start of painting was measured, the amount of meandering was about 3 mm. Therefore, at the start of coating, the width of the narrow film at the coating position was set to the steel plate width (1000 mm) +6 mm. The edge position of the steel sheet and the boundary position between the narrow film and the wide film (narrow layer end 24) were measured using a CCD camera 21 and an image processing device 22 as shown in FIG. In Example 1, the outer single layer portion was discarded at the start of coating, whereas in Example 3, the outer single layer portion was recovered from the start of coating.

  Thereafter, since the meandering amount of the steel plate was stabilized to 1 mm, the position of the edge guide 6a of the curtain discharge device 1 was adjusted, and the width 33 of the narrow film was readjusted to the steel plate width (1000 mm) +3 mm. As a result, the amount of the mixed paint collected and discarded by the inner collection unit is halved when it is stable compared to when coating is started.

  As described in Example 3, when the amount of meandering of the steel sheet at the start of coating was measured, the amount of meandering was about 3 mm. Therefore, at the start of painting, the CCD camera 21 shown in FIG. 4 is used to recognize the edge position of the steel sheet, the edge position of the narrow film, and the separation position of the collection device by image processing, and the edge position and width of the steel sheet. The position of the curtain discharge device 1 was adjusted so that the distance from the end position of the narrow membrane was constant. For the position adjustment, a stepping cylinder 23a shown in FIG. 5 was used. In addition, the position of the collection pot 15 was moved using the stepping cylinder 19 shown in FIG. 6, and the separation position 12 between the outer collection section and the inner collection section was moved in the lateral direction.

  As a result, the width of the narrow film can be made to be the steel plate width (1000 mm) +3 mm from the beginning of the coating, and the recovered amount of the mixed paint that is recovered and discarded at the inner recovery portion is compared with that of Example 3. It was further reduced.

It is a figure which shows the curtain coating method of this invention. It is a figure which shows the curtain coating method of this invention. It is a figure which shows a mode that the width | variety of a narrow layer is adjusted by operation | movement of an edge guide. It is a perspective view which shows the test | inspection condition by a width | variety detection apparatus. It is a figure which shows the condition which moves a curtain discharge apparatus and a collection | recovery apparatus in the width direction. It is a figure which shows embodiment of the curtain coating method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Curtain discharge device 2 Discharge slit 3 Inclined surface 4 Inclined end 5 Guide device 5a Guide chain 5b Weight 6 Edge guide 10 Curtain 11 Plate 12 Separation position 14 Collection device 15 Collection pot 16 Collection pan 17 Partition plate 18 Moving device 19 Stepping cylinder 20 Illumination device 21 CCD camera 22 Image processing device 23 Stepping cylinder 24 Narrow layer end 25 Curtain end 26 Plate travel direction 27 Intermediate pan 28 Shutter 30 Full curtain width (discharge position)
31 Width of narrow layer (discharge position)
32 Full curtain width (coating position)
33 Width of narrow layer (coating position)
34 Width of Plate 35 Inner Multilayer Portion 36 Outer Single Layer Portion 40 Inner Recovery Portion 41 Outer Recovery Portion

Claims (7)

  In a curtain coating method in which a curtain composed of a plurality of layers of liquid film is dropped and a plurality of layers of film are coated on the surface of a traveling plate, the width of at least one layer of the liquid film constituting the falling curtain is greater than the total width of the curtain The width of the curtain at the coating site is wider than the width of the traveling plate, and the curtain flowing down outside the width ends of the plate is divided into the width end side of the curtain and the end side of the plate. Curtain coating method characterized by collecting separately in   The width of the layer having a width narrower than the full width of the curtain (hereinafter referred to as “narrow layer”) is wider than the width of the plate, and the width end side of the curtain and the end side of the plate The curtain coating method according to claim 1, wherein a separation position to be collected separately is in the vicinity of a width end portion of the narrow layer.   The curtain coating method according to claim 2, wherein the width direction position of the curtain discharge device that discharges a curtain and the separation position are adjusted according to the width direction shift position of the traveling plate. In a curtain coating apparatus that has a curtain discharge device that discharges a plurality of liquid films and drops a curtain made of the discharged multiple layers of liquid film, and coats a plurality of layers of film on the surface of a traveling plate. The width of at least one layer of the liquid film constituting the curtain to be made can be narrower than the full width of the curtain (hereinafter referred to as “narrow layer”), and the full width of the curtain at the coating site is larger than the width of the traveling plate Curtain coating characterized by having a collecting device that can collect a curtain that can be wide and flows down outside both ends of the width of the plate separately on the width end side of the curtain and the end side of the plate apparatus.   5. The curtain according to claim 4, wherein the collecting device includes a moving device for moving in a curtain width direction a separation position where the collecting is separately performed on the curtain width end side and the plate end side. Coating equipment.   6. The curtain coating apparatus according to claim 4, further comprising a width detecting device that detects a width end position of the narrow layer and an end position of the steel plate.   The curtain coating device according to any one of claims 4 to 6, wherein the curtain discharge device and the recovery device are movable in a width direction of a traveling plate.

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