JP2000157900A - Coating device and method for building member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a coating having almost uniform thickness without bubbles with reduced coating quantity. SOLUTION: In a coating method of an outer wall disclosed herein, a coating object matter 1 is placed on a conveyor and is passed through a spray booth 2, a vacuum booth 3 and a pressurized booth 4 sequentially. In the spray booth 2, a coating is atomized and sprayed on a surface of the coating object matter 1 by a spray coating machine 5 so as to form a liquid coating film layer La, and in the vacuum booth 3 the liquid coating film layer La formed on the surface of the coating object matter 1 is defoamed, and in the pressurized booth 4 air is blown to a liquid coating film layer Lb on the surface of the coating object matter 1 that is being passed through the inside of the booth 4 and simultaneously air is allowed to flow from the pressurized booth 4 to the vacuum booth 3 through an opening 84, and because the above air flow works as an air knife when the coating object matter 1 (its part) passes through the opening 84, the liquid coating film layer Lb formed on the surface is made thin almost uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method and a coating apparatus for building members, and more particularly, to a method for applying a coating to the surface of an outer wall material such as ALC or a hard wood chip cement board having an uneven pattern on the surface. The present invention relates to a coating method and a coating apparatus for a building member suitable for use.

[0002]

2. Description of the Related Art Conventionally, as an outer wall of a building, there have been many outer walls constructed at a construction site, such as earth walls coated with soil or the like. The outer wall, in which the timber is attached to the outer wall portion of the building, has been widely used because it can be constructed quickly, uniformly and beautifully. ALC (Autoclaved Lig)
ht-weight Concrete), precast concrete outer wall, hard wood cement board, etc. In particular, ALC outer wall materials are often produced because they are similar in appearance to outer wall materials made of precast concrete, and are light and easy to construct. Recently, as an outer wall material of a building such as a house, a material provided with a deeply carved uneven pattern has been favored by owners because of its luxurious appearance.

[0003] A paint is usually applied to the surface of such an outer wall material in order to improve the appearance and to prevent absorption of moisture. In particular, the outer wall material made of ALC has many air bubbles inside, and water such as rainwater penetrates into the air bubbles inside, and this water freezes in winter and destroys the outer wall material, so-called frost damage occurs. In order to prevent this frost damage, a coating material having low water permeability is always applied. In addition, even if the outer wall material is made of hard wood chip cement board, if the surface is cut to provide a deeply carved uneven pattern, wood chips will appear in the cut parts, and these wood chips will absorb water such as rainwater and decay, and in the winter, However, it is necessary to apply a paint because the moisture freezes and destroys the outer wall material. Conventionally, as a coating method for applying a paint to the surface of such an outer wall material, there are a brush coating method, a spray coating method, a roll coater, a flow coater, a dipping method and the like.

[0004] The brush coating method is a method in which the surface of the outer wall material is stroked with a brush to which a paint is applied, and is the most primitive method. This brush coating method puts the brush in a paint reservoir, makes the paint adhere to the brush, and strokes the surface of the outer wall material to apply it, so it is suitable for repairing the outer wall material produced in small quantities and the painted surface of the outer wall material. However, since it is not suitable for mass production, it has not been adopted in the mass production process of exterior wall materials.

[0005] The spray coating method is a method of spraying paint from a nozzle at the tip of a spray and spraying the sprayed paint onto the surface of an outer wall material, and includes an air spray method and an airless spray method (for example, JP-A-2-119964 and the like). The air spray system consists of a compressed air passage leading to the nozzle at the tip of the spray gun and a passage leading from the paint reservoir to the compressed air passage.The compressed air passes through the compressed air passage to the nozzle at the tip of the air gun. When air is allowed to pass, the pressure in the compressed air passage is reduced, and paint in the paint reservoir is sucked in through the passage leading to the compressed air passage, and the sucked paint and air come out of the nozzle together and paint. How to With the airless spray method, a passage leading from the paint reservoir to the nozzle at the tip of the spray gun is provided, and when compressed air is introduced into the paint reservoir, the paint in the paint reservoir is pushed out to the passage by the pressure of this compressed air. This is a method in which paint is sprayed out from a nozzle at the tip of a spray gun to perform painting. In this spray coating method, paint can be sprayed on the surface of the outer wall material, so that even a deeply carved outer wall material can be applied, and this method is employed for coating various outer wall materials.

[0006] The roll coater is a device in which a part of the surface of a rotating roll is dipped in a paint reservoir to cause the paint to adhere to the roll surface, and the paint attached to the roll surface is moved to the surface of the outer wall material. is there. In this roll coater, there are a method in which the rotation direction of the roll and a direction in which the outer wall material passes are the same and those in the opposite method. This roll coater is used in the case of an outer wall material having a smooth surface in order to move the paint adhered to the roll to the surface of the outer wall material, but is used in an outer wall material having a concave portion such as a deeply carved outer wall material. Unable to apply paint to recesses. Therefore, it is not employed for painting the outer wall material having a concave portion.

The flow coater is a method in which the paint overflows from the side wall of the paint reservoir in the form of a film, the outer wall material is passed through the film-like paint, and the paint is applied to the surface of the outer wall material. This flow coater, on the surface of the outer wall material with a smooth surface,
The paint can be applied almost uniformly, and it is used in the case of an outer wall material with a smooth surface.However, if there is a concave portion such as an outer wall material with a deep carved surface, the paint will accumulate in the concave portion. Is not suitable. Therefore, it is not used for painting an outer wall material having a concave portion.

The dipping method is a method in which an outer wall material is submerged in a paint reservoir and applied. Since the paint is applied to the entire surface such as the front surface and the back surface, this dipping method cannot be adopted when it is desired to apply the coating only to the surface of the outer wall. Since it is often applied to the concave portions, it is not adopted for painting an outer wall material having a deep carved surface. As can be seen from the above description, the spray coating method is often employed for the outer wall material having a concave portion.

[0009]

However, even with the conventional spray coating method which is considered to be the most effective method of applying the surface of the outer wall material, the outer wall material made of ALC having a deep carving or hard wood chips can be used. Many problems arise when painting an exterior wall material made of cement board. That is, if there is a deep carving of a groove or the like, the amount of paint applied from the spray differs between the groove and the general part (non-groove). Also, ALC
In the outer wall material, many bubbles appear on the surface at the time of manufacture and become uneven, so when applying a paint to this surface by the spray method, it is not applied to the inside of the unevenness, and the inside of the unevenness contains bubbles. After the paint is dried, the bubbles are broken, and this portion is not painted or the paint film is thin. Even with a hard wood chip cement board, if the surface is shaved to a deeply carved surface, there is a problem that wood chips appear on this surface, and the shaded portions of the wood chips remain as bubbles without being painted.

In order to prevent rainwater from penetrating from the groove to which a small amount of paint is applied or the uneven portion where air bubbles are broken, the paint may be applied thickly, but a large amount of paint is required and wasteful Disadvantage. In order to avoid this inconvenience, the grooves and the like may be specially repainted or painted first, but there is a problem that the process becomes complicated and the work time becomes long. By the way, recently, a coating method has been developed in which air is blown on the surface of the outer wall material to move the paint adhered to the surface and make the thickness of the coating uniform, but in the case of a deeply carved outer wall material. In addition, the coating amount cannot be made completely uniform, and air bubbles cannot be eliminated.

The present invention has been made in view of the above-mentioned circumstances, and makes it possible to apply a coating film to a deeply carved architectural member such as an outer wall material made of ALC or wood chip cement board. The thickness can be beautifully applied to a substantially uniform thickness between the groove portion and the general portion (non-groove portion) without increasing the thickness, and the application can be reliably performed without leaving uncoated portions. It is an object of the present invention to provide a coating method and a coating apparatus for a building member having low water permeability and being resistant to frost damage.

[0012]

In order to solve the above-mentioned problems, the invention according to claim 1 relates to a coating apparatus for applying a paint to a surface of a work to be coated as a building member. A first booth provided with a spray application means for spraying a paint on the surface of the first to form a liquid coating layer;
A second booth disposed at the rear of the booth and having an air suction port of a blower therein, and a third booth disposed at the rear of the second booth and having an air outlet of the blower therein. And the second booth and the third booth are separated from each other by a partition plate, and at the lower end of the partition plate or between the partition plate and the floor surface. An opening for an air knife through which the object to be coated can be provided,
On the floor of each of the booths, place the object to be coated,
A conveyor for passing through the first booth, the second booth, and the third booth in this order is laid via the air knife opening between the second booth and the third booth. , The object to be coated is placed on the conveyor,
When passing through the opening for the air knife, the liquid coating layer formed on the surface of the object to be coated in the first booth is pressurized by the operation of the blower. It is characterized in that a thin film is formed substantially uniformly from the inside of the booth to the second booth in a reduced pressure state by the flow of air flowing through the air knife opening.

According to a second aspect of the present invention, there is provided the building member coating apparatus according to the first aspect, wherein in the third booth, the air outlet is formed on a surface of the workpiece. The liquid coating layer is provided in such a manner as to blow air.

According to a third aspect of the present invention, there is provided the coating device for building members according to the first aspect, wherein the partition plate for partitioning the second booth and the third booth is provided at the opening for the air knife. The gap between the conveyor and the object to be coated on the conveyor passing through the partition plate is set to 5 to 30 mm.

According to a fourth aspect of the present invention, there is provided the building member coating apparatus according to the first aspect, wherein the partition plate for partitioning the second booth and the third booth is provided at the air knife opening. A gap adjusting means for adjusting the gap between the conveyor and the object to be coated on the conveyor passing through the partition plate is provided.

According to a fifth aspect of the present invention, there is provided the coating apparatus for building members according to the first aspect, wherein the shape of the lower side of the partition plate for partitioning the second booth and the third booth is the conveyor. And a shape substantially similar to the surface contour of the object to be coated on the conveyor along a direction orthogonal to the moving direction of the object.

According to a sixth aspect of the present invention, there is provided the coating device for building members according to the first aspect, wherein the opening for the air knife has at least a ceiling or eave having a predetermined depth. It is characterized by.

According to a seventh aspect of the present invention, there is provided the building member coating apparatus according to the sixth aspect, wherein the ceiling or the eave of the opening for the air knife is from the third booth side to the second booth side. It is characterized by a downward slope toward.

The invention according to claim 8 relates to the coating apparatus for building members according to claim 1, wherein the first booth and the second booth are also separated from each other by a partition plate, and
At the lower end of the partition plate, or between the partition plate and the floor surface, an opening through which the object to be coated can pass is provided, and when the blower is operated, the opening passes through the opening, and It is characterized in that the air in the first booth flows into the second booth in a reduced pressure state.

According to a ninth aspect of the present invention, there is provided the building member coating apparatus according to the first aspect, wherein the object to be coated is placed on the conveyor, and a loading port provided in the third booth is provided. The liquid coating layer formed on the surface of the object to be coated is discharged to the outside from the third booth in a pressurized state by the operation of the blower when the sheet is carried out to the outside. It is characterized in that a thin film is formed more uniformly by the force of the air flow.

The invention according to claim 10 is the same as the invention according to claim 9.
According to the building member coating apparatus described above, the carry-out port provided in the third booth has at least a ceiling or an eave having a depth of a predetermined length.

The invention according to claim 11 is the first invention.
According to the coating device for building members described in Item 0, the ceiling or eaves of the carry-out port is entirely or partially in the depth direction descending from the third booth side to the outside. It is characterized by:

The invention according to claim 12 is the first invention.
The present invention relates to a method of coating a building member using the coating apparatus according to any one of the above items 1 to 10, wherein an object to be coated as the building member is placed on the conveyor, and the first booth and the second booth are provided. And a third booth, and in the first booth, a paint is sprayed on the surface of the object by the spray applying means to form a liquid coating layer. In the second booth, the blower is used. Is operated to reduce the pressure in the second booth to defoam the liquid coating layer formed on the surface of the object to be coated. In the third booth, the blower is operated to operate the coating object. In a mode in which air is blown onto the liquid coating layer formed on the surface of the object, the inside of the third booth is pressurized, and the opening for the air knife between the second booth and the third booth is opened. Through the air from the third booth to the second booth Was flowing, resting on the conveyor, the object to be coated is, when passing through for the air knife opening, it is characterized in that substantially uniformly thinned the liquid coating layer formed on the surface thereof.

The thirteenth aspect of the present invention is the first aspect of the present invention.
According to the method for coating a building member according to 2, the object to be coated is
The liquid coating layer formed on the surface of the object to be coated is brought into a pressurized state by the operation of the blower when being carried out through the carry-out port provided in the third booth. The third booth is characterized in that a thin film is formed more uniformly by the flow of air discharged from the third booth to the outside via the carry-out port.

The invention according to claim 14 is the first invention.
The method for coating a building member according to item 2 or 13, wherein the building member, which is an object to be coated, is an outer wall material provided with an embossed pattern, a concave portion, a convex portion, or a groove on the surface.

The invention according to claim 15 is the first invention.
4. According to the method for coating a building member described in 4, the outer wall material is A
It is characterized by LC or hard wood chip cement board.

Further, the invention according to claim 16 relates to the method for coating a building member according to claim 12 or 13, wherein the building member to be coated is an accessory.

[0028]

In the structure of the present invention, the outer wall material first enters the spray booth from the entrance. In the first booth, a coating material is sprayed on the surface of the object to be coated by a spray applying means to form a liquid coating layer. Next, the outer wall material enters the second booth. The second booth is in a reduced pressure state due to the operation of the blower. Therefore, while the object to be coated is passing through the depressurized second booth, bubbles generated in the liquid coating layer are spontaneously broken and defoamed. Bubbles generated behind the wood chips appearing on the surface of the wood cement board are removed. At this time, the air in the first booth, including the solvent and the paint splash,
It is sucked into the second booth under reduced pressure. As a result, air containing solvent or paint splatters hardly leaks out of the apparatus from the first booth, which is very preferable in terms of environmental hygiene.

In the third booth, by operating the blower,
It is in a pressurized state. Therefore, the second booth and the third
A strong air flow flows from the third booth side in a pressurized state to the second booth side in a depressurized state at the air knife opening between the booths. In such a state, when the object to be coated is placed on the conveyor and tries to pass through the opening for the air knife, the strong air flow flowing from the third booth to the second booth acts as an air knife, and thus the surface of the object to be coated is Is thinned. At this time, the paint moves from the thick paint area to the paint-deficient area due to the force of the air flow, so that the surface of the building member is covered with a substantially uniform paint film. That is, at the second booth,
Even if the thickness of the coating is different between the groove of the deeply carved object and the general part, between the area where the air bubbles are broken and the area where the air bubbles are not originally generated, this object is When passing through the opening for the air knife between the second booth and the third booth on the conveyor, a strong air flow causes the paint in the thick area of the paint to become the area where the paint is insufficient. And the surface of the building member is covered with a substantially uniform paint film.

In the third booth, air is blown from almost right above the surface of the object to be coated, whereby the liquid coating layer is pressed. Therefore, even after the object to be coated has passed through the opening for the air knife, if the coating still has unevenness, the pressure moves the paint to the area where the paint is insufficient and to the area where the paint is thick. To ensure that the surface of the building member is covered with a substantially uniform paint film. Finally, the outer wall material comes out of the exit of the third booth. At this time, the thickness of the liquid coating layer is further reduced by the force of the air flow discharged from the third booth in a pressurized state to the outside of the apparatus, and the liquid coating layer is further thinned.

Therefore, according to the structure of the present invention, AL
Even for deeply carved architectural members, such as outer wall materials made of C or wood chip cement boards, etc., between the groove and the general part (non-groove) without uneconomically thickening the coating film. It can be applied beautifully to a substantially uniform thickness, and can be applied reliably without leaving uncoated portions.
A building member having low water permeability and being resistant to frost damage can be obtained.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. The description will be specifically made using an embodiment. First Embodiment FIG. 1 is a cross-sectional view schematically showing the configuration of a coating apparatus for an outer wall material according to a first embodiment of the present invention. FIG. FIG. 3 is an explanatory view for explaining the operation of this example, and is a schematic diagram showing a state in which the thickness of the paint applied to the outer wall material changes as the process proceeds. FIG. 4 is a schematic cross-sectional view, and FIG. 4 is an explanatory view for explaining the operation of this example. FIG. 4 is a schematic plan view showing the flow of air in the coating apparatus.
FIG. 4 is a diagram showing actual measurement values of quality comparison with the conventional technology, and is a chart showing a relationship between an application amount and a water permeability.

The coating apparatus of this example is an outer wall material (object to be coated)
A spray booth (first booth) 2 and a spray booth (first booth) 2, as shown in FIG. It comprises a pressure reducing booth (second booth) 3, a pressure booth (third booth) 4, a spray coater 5, a circulation blower 6, and a roller conveyor 7.

The spray booth 2 is provided with a spray coating machine 5 on its ceiling, so that paint is sprayed on the surface of the outer wall material 1 passing through the spray booth 2. That is, in the spray coating machine 5,
Paint passes from inside a pipe 51 from a paint reservoir (not shown),
It is sprayed in the form of a mist from a nozzle 52 provided at the tip of the spray coating machine 5. The paint sprayed in mist is
It pours down onto the surface of the outer wall material 1 that passes below, thus forming the liquid coating layer La (see FIG. 3). Decompression booth 3
In the ceiling, an air suction port 61 communicating with the circulation blower 6 is provided on the ceiling, and when the circulation blower 6 operates,
The inside of the booth 3 is depressurized, and bubbles in the paint (liquid coating layer) applied to the surface of the outer wall material 1 passing through the booth 3 are removed. In the pressurizing booth 4, an air outlet 62 communicating with the circulation blower 6 is provided at the ceiling thereof. Air is blown against the outer wall material 1 passing through the pressure chamber to pressurize the outer wall material 1 to make the coating film uniform.

The spray booth 2 is provided with a carry-in port 81 into which the outer wall material 1 before coating is applied. On the other hand, in the pressurized booth 4, a carry-out port 8 through which the outer wall material 1 after applying the paint is discharged.
2 are provided. The spray booth 2 and the decompression booth 3 are separated from each other by a partition plate 91, and the decompression booth 3 and the pressurization booth 4 are separated from each other by a partition plate 92. Openings 83 and 84 through which the outer wall material 1 passes are provided at lower ends of these partition plates 91 and 92.

The circulation blower 6 sucks the air in the decompression booth 3 from the air suction port 61, and
It is configured to spray on the surface of the outer wall material 3 passing through the inside of the pressure booth 4. When the circulation blower 6 is operated, the air in the decompression booth 3 is sucked, so as shown in FIG.
The air Ga passing through the spray booth 2 from above and the air Gb from the pressurizing booth 4 are sucked into the depressurizing booth 3 so that air contained in the solvent and paint splashes in the spray booth 2 is not discharged to the outside of the apparatus as much as possible. ing. The air blown out from the air outlet 62 to the pressurizing booth 4 blows out to the decompression booth 3 via the opening 83 and also blows out of the apparatus via the carry-out outlet 82, which will be described later. Functions as an air knife.

The roller conveyor 7 includes a plurality of rolls 71, 71,..., Which are rotationally driven by a driving device (not shown), arranged at equal intervals and in parallel with each other. It is laid on the floor of the spray booth 2, the decompression booth 3, and the pressurization booth 4 so as to pass through the openings 83, 84 below the 92 and the carry-out port 82. Therefore, when the mounting table 72 made of a frame is mounted on the roller conveyor 7 and the outer wall material 1 is mounted thereon, the mounting table 7
The outer wall material 1 resting on 2 enters the loading booth 81 of the spray booth 2 together with the mounting table 72, and sequentially passes through the spray booth 2 → the partition 91 → the decompression booth 3 → the partition 92 → the pressure booth 4. Then, it exits from the outlet 82 of the pressurizing booth 4. In this example, the mounting table 7 on the roller conveyor 7
2, when the outer wall material 1 passes through the opening 84 below the partition plate 91, the gap height between the partition plate 91 (upper edge of the opening 84) and the outer wall material 1 is 5 to 30 mm (preferably, Is 10
20 mm).

Exterior wall material (object to be coated) 1 used in this example
Is, as shown in FIG.
mm, approximately 450 mm in width and approximately 150 mm in height, and the surface thereof is provided with deep joints 11, 12,...

The paint applied to the outer wall material 1 includes alkyd resin paint, aminoalkyd resin paint, unsaturated polyester resin paint, epoxy resin paint, polyurethane resin paint,
A solvent-based paint such as a thermosetting acrylic resin paint, a water-soluble resin paint, or an emulsion paint may be used. However, an acrylic emulsion paint is most preferable from the viewpoints of pollution, weather resistance, and the like.

Next, using the coating apparatus having the above configuration, FIG.
In order to paint the outer wall material 1 made of ALC as shown in FIG.
The spray applicator 5 and the circulation blower 6 are operated. Next, the mounting table 72 is mounted on the roller conveyor 7, and the outer wall material 1 is mounted on the mounting table 72. Then, as shown in FIG. 2, the outer wall material 1 placed on the mounting table 72 enters the spray booth 2 from the carry-in port 81 together with the mounting table 72.

In the spray booth 2, as shown in FIG. 3, the paint is sprayed in a mist form from the nozzle 52 at the tip of the spray coater 5 on the surface of the outer wall material (object to be coated) 1 to form a liquid coating layer La. It is formed. However, the liquid coating layer La formed in the spray booth 2 is relatively thick (1-2 m).
(thickness of m), but the film thickness unevenness is remarkable, many bubbles remain inside, and there are cases where unpainted portions exist in the grooves 11, 12 and the like.

Next, the outer wall material 1 enters the decompression booth 3. The decompression booth 3 is in a depressurized state by the operation of the circulation blower 6. Therefore, while the outer wall material 1 passes through the decompression booth 3, the air bubbles generated in the liquid coating film La are spontaneously broken and defoamed. Is excluded. At this time, the air in the spray booth 2 containing the solvent and the paint is sucked into the decompression booth 3. As a result, air containing solvent and paint splashes is less likely to leak from the spray booth 2 to the outside of the apparatus, which is very preferable for environmental hygiene.

The pressurizing booth 4 is pressurized by the operation of the circulation blower 6. Therefore, decompression booth 3
8 at the lower end of a partition plate 92 for partitioning the pressure booth 4
Through 4, a strong air flow flows from the pressurizing booth 4 side to the depressurizing booth 3 side.

In such a state, when the outer wall material (object to be coated) 1 tries to enter the pressure booth 4 through the opening 84 at the lower end of the partition plate 92 that separates the pressure reduction booth 3 and the pressure booth 4 from each other. As shown in FIG. 3 and FIG.
Since the strong air flow Gb flowing from the side to the decompression booth 3 side works as an air knife, the liquid coating layer L on the surface of the outer wall material 1 is formed.
b is thinned. At this time, since the paint moves from the thick paint area to the paint-deficient area by the force of the airflow Gb, the surface of the outer wall material 1 is covered with the substantially uniform liquid coating layer Lb. . That is, the decompression booth 3
In this case, the thickness of the coating film differs between the grooves 11 and 12 of the deeply carved outer wall material 1 and the general portion (non-groove portion), between the region where air bubbles are broken and the region where air bubbles are not originally generated. However, when the outer wall material 1 is placed on the roller conveyor 7 and passes through the opening 84 between the decompression booth 3 and the pressurization booth 4, the outer wall material 1 receives a strong airflow Gb and receives a thick paint ( The paint of the general portion (non-groove portion) or the region where bubbles are not generated originally is washed away by the region where the paint is insufficient (the regions where the grooves 11 and 12 and the bubbles are broken), and the surface of the outer wall material 1 is substantially reduced. Covered with a uniform paint film.

When the outer wall material 1 enters the pressure booth 4,
By the operation of the circulation blower 6, air is blown from the air outlet 62 at the ceiling of the pressurizing booth 4 to the surface of the liquid coating layer Lb on the floor side, whereby the liquid coating layer Lb is pressurized. Therefore, even after the outer wall material 1 has passed through the opening 84, when the coating film unevenness still exists, the paint moves to the region where the paint is insufficient and the region where the paint is thick due to the pressing force. The surface of the outer wall material 1 is surely covered with a substantially uniform liquid coating layer Lb.

Finally, the outer wall material 1 comes out of the outlet 82 of the pressure booth 4. Also at this time, the liquid coating layer Lc
As shown in FIGS. 3 and 4, the thickness of the coating film is further made uniform by the force of the airflow Gc discharged from the pressurizing booth 4 to the outside of the apparatus, and the coating film is reduced to a thickness of 70 to 80 μm. You.

As described above, according to the configuration of this example, the air flows Gb and G are also applied to the outer wall material 1 such as a deeply carved ALC.
Because the paint moves to the area where the paint is insufficient due to c or air pressure, the paint moves to the area where the paint is insufficient, so that the paint film is not uneconomically thickened, and even between the groove parts 11 and 12 and the general part (non-groove part). The outer wall material 1 can be applied beautifully to a substantially uniform thickness, and can be applied reliably and quickly without leaving any unpainted state. Therefore, the outer wall material 1 has low water permeability and is resistant to frost damage. Can be.

Next, a comparative experiment was conducted to compare the superiority of the coating method of this example with the conventional representative coating method.
The following four coating methods were used for this comparative experiment. (1) A method of applying twice to the ALC outer wall material by the coating method of this embodiment. (2) A method of applying the ALC outer wall material twice only by simply spray coating (Comparative Example 1). (3) A method in which spray coating is applied to the ALC outer wall material for the first time, and compressed air is blown for the second time (Comparative Example 2). (4) A method of spraying and applying compressed air to the ALC outer wall material twice (Comparative Example 3). In the experiment, using the above-mentioned respective coating methods, an allyl-based emulsion paint was applied twice to the outer wall material made of ALC, and the relationship between the applied amount (Kg / m ² ) and the water permeability (cc / 24 hr. 75 p). Was measured. The material, shape, and dimensional conditions were the same for each coating method except that the coating methods were different from each other. The results of the comparative experiment are shown in Table 1 and FIG. Table 1 and FIG. 5 show the general portion, the vertical groove portion, the horizontal groove portion, and the cross in the coating region applied to the surface of the ALC outer wall material by the coating methods of this example and comparative examples 1, 2, and 3. The measured values of the amount of application and the amount of water permeation at each of the two portions of the groove are shown. Here, the general portion ○ indicates a non-groove region on the surface of the ALC outer wall material, the parallel groove portion □ indicates the groove portion 12 extending in parallel with the traveling direction of the ALC outer wall material, and the vertical groove portion △ indicates the ALC outer wall material.
The groove 11 extends in a direction perpendicular to the traveling direction of the outer wall material, and the cross groove ◇ indicates a groove in a region where the parallel groove and the vertical groove cross in a cross shape. The application amount is the amount of the paint after drying.

As is clear from Table 1 and FIG. 5, Comparative Example 1 has a large amount of water permeation in the groove portions (parallel groove portions, vertical groove portions, cross-shaped groove portions), but is insufficient, despite the large amount of application. Further, it can be seen that Comparative Example 2 has insufficient water permeability in the groove portions (parallel groove portions, vertical groove portions, and cross groove portions) although the application amount is the next largest, which is insufficient. In Comparative Example 3, the coating amount was relatively small, and in the general portion, the coating material was substantially uniform and the amount of water permeability was extremely small. I understand. On the contrary, according to the method of this embodiment, the coating amount is small,
Moreover, it can be seen that the water permeability of the groove portion is small and extremely excellent.

[0050]

[Table 1]

Second Embodiment FIG. 6 is a cross-sectional view schematically showing a configuration of an outer wall material coating apparatus according to a second embodiment of the present invention. The difference between the configuration of the second embodiment and that of the first embodiment is as follows.
As shown in FIG. 6, an eave portion (or a ceiling portion) having a predetermined depth is provided at the opening 84a and the carry-out opening 82a which are the carry-in entrance of the outer wall material 1 to the pressurizing booth 4. It is. The eaves (or ceiling) are provided so as to protrude outward from the pressure booth 4. If you do this,
Since a laminar air flow is obtained near the opening 84a and the outlet 82a serving as an air knife, a more uniform coating film can be obtained.

Third Embodiment FIG. 7 is a sectional view schematically showing the configuration of an apparatus for coating an outer wall material according to a third embodiment of the present invention. In the third embodiment,
As shown in FIG. 7, an eave portion (or a ceiling portion) that is downwardly sloping outward is provided at the opening 84 b and the outlet 82 b that are the entrance of the outer wall material 1 to the pressurizing booth 4. I have.
In this way, the opening 84b serving as an air knife
In addition, since a laminar flow of a high-speed air flow is obtained near the carry-out port 82b, a more uniform coating film can be obtained.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like that do not depart from the gist of the present invention. Is also included in the present invention. For example, in this embodiment, a roll conveyor is used, but a belt conveyor or a suspended conveyor may be used. Further, the outer wall material is not limited to ALC, and may be, for example, a hard wood chip cement board. The object to be coated is not limited to the outer wall material, but may be another building member. Further, in the above-described embodiment, the mounting table was placed on the roll conveyor, and the outer wall material was placed on the mounting table and passed through each booth. May be passed. In FIG. 6, one of the opening 84a and the carry-out port 82a, which are the carry-in port of the outer wall material 1 to the pressurizing booth 4, can be omitted. The same applies to FIG.

As shown in FIG. 8, the openings 84, 84a, 84b, which are the entrances of the outer wall material 1 to the pressurizing booth 4, are provided.
Or, height adjusting means (or gap adjusting means) for adjusting the air volume, if necessary, at the outlets 82, 82a, 82b.
Providing the 85 and 86 makes it possible to quickly respond to a change in the object to be coated, thus greatly improving the usability. Also, as shown in FIGS. 9A and 9B, openings 84c and 84d, which are entrances of the outer wall material 1 to the pressurizing booth 4, are provided.
Or, the shapes of the outlets 82c, 82d are along the direction orthogonal to the moving direction of the conveyor, and the objects to be coated 1c,
If the shape is roughly similar to the surface contour of 1d, the building member to be painted can be more effectively applied when the building member is an accessory.

[0055]

As described above, according to the structure of the present invention, airflow and air pressure can be reduced even for deeply carved architectural members such as outer wall materials made of ALC or wood chip cement board. As a result, the paint moves to an area where the paint is insufficient and to an area where the paint is thick, so that the paint film does not need to be uneconomically thickened. It can be applied beautifully, and it can be applied without leaving any unpainted area.
A building member having low water permeability and being resistant to frost damage can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a configuration of an outer wall material coating apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an outer wall material (which is an object to be coated) made of ALC on which joint groove patterns are provided in a vertical direction and a horizontal direction.

FIG. 3 is an explanatory diagram for explaining the operation of the embodiment, and is a schematic cross-sectional view showing a state where the thickness of the paint applied to the outer wall material changes as the process proceeds.

FIG. 4 is an explanatory diagram for explaining an operation of the embodiment, and is a schematic plan view showing a flow of air in the coating apparatus.

FIG. 5 is a diagram showing measured values of quality comparison with a conventional technology, and is a table showing a relationship between an application amount and a water permeability.

FIG. 6 is a cross-sectional view schematically showing a configuration of an outer wall material coating apparatus according to a second embodiment of the present invention.

FIG. 7 is a sectional view schematically showing a configuration of a coating apparatus for an outer wall material according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view schematically showing a configuration of a coating apparatus for an outer wall material according to a modification of the embodiment of the present invention.

FIG. 9 is a cross-sectional view schematically showing a configuration of an external wall material coating apparatus which is another modification of the embodiment of the present invention.

[Explanation of symbols]

 1, 1c, 1d Exterior wall material (object to be coated) 11 Vertical groove 12 Horizontal groove 2 Spray booth (first booth) 3 Decompression booth (second booth) 4 Pressurization booth (third booth) 5 Spray coating machine (Spray application means) 6 Circulation blower (blower) 61 Air suction port 62 Air outlet 7 Roller conveyor (Conveyor) 81 Carry-in port 82 Carry-out port 83 Opening 84 Opening (air knife opening) 91, 92 Partition plate La, Lb, Lc Liquid coating layer Ga, Gb, Gc Air flow

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D073 AA01 BB03 DB22 DB24 DD02 DD11 DD25 DD32 4D075 AA04 BB57Z CA32 CA48 DB12 DC03 EA13 EB22 EB38

Claims (16)

[Claims] 1. A coating apparatus for applying a paint to a surface of an object to be painted, which is a building member, comprising: a spray applying means for spraying the paint onto the surface of the object to form a liquid coating layer. A first booth comprising: a second booth disposed downstream of the first booth and having an air suction port of a blower therein; and a second booth disposed downstream of the second booth; A third booth having an exit inside, the second booth and the third booth are separated from each other by a partition plate, and at a lower end portion of the partition plate, or An opening for an air knife through which the object to be coated can pass is provided between the partition plate and the floor, and the object to be coated is placed on the floor of each booth,
A conveyor for passing through the first booth, the second booth and the third booth in this order is laid via the air knife opening between the second booth and the third booth. When the object to be coated is placed on the conveyor and passes through the opening for the air knife, the liquid coating layer formed on the surface of the object to be coated in the first booth includes: By the operation, from the inside of the third booth in the pressurized state to the second booth in the depressurized state, by the flow of the air flowing through the opening for the air knife,
A coating device for a building member, wherein the coating member is configured to be formed into a substantially uniform thin film. 2. In the third booth, the air outlet is provided in such a manner that air is blown onto the liquid coating layer formed on the surface of the object to be coated. Item 6. A coating device for a building member according to Item 1. 3. The method according to claim 2, wherein the opening for the air knife is the second
The gap between the partition plate separating the booth and the third booth and the object to be coated on the conveyor passing through the partition plate is set to 5 to 30 mm. The coating device for building members according to claim 1. 4. The air knife according to claim 2, wherein the air knife has a second opening.
And a gap adjusting means for adjusting a gap interval between the partition plate that separates the booth from the third booth and the object to be coated on the conveyor that passes through the partition plate. The coating device for a building member according to claim 1. 5. A surface profile of the object to be coated on the conveyor, wherein a shape of a lower side of the partition plate separating the second booth and the third booth is along a direction orthogonal to a moving direction of the conveyor. The building member coating apparatus according to claim 1, wherein the apparatus has a shape substantially similar to that of the first embodiment. 6. The coating device for a building member according to claim 1, wherein the opening for the air knife has at least a ceiling or an eave having a depth of a predetermined length. 7. The building according to claim 6, wherein the ceiling or the eave of the opening for the air knife has a descending slope from the third booth side to the second booth side. Equipment for coating components. 8. The first booth and the second booth are also separated from each other by a partition plate, and at the lower end of the partition plate or between the partition plate and the floor surface, An opening through which the object to be coated can be provided is provided. When the blower is operated, the air in the first booth flows into the second booth in a reduced pressure state through the opening. The coating device for a building member according to claim 1, wherein: 9. The liquid on the surface of the object to be coated when the object to be coated is loaded on the conveyor and is carried out of the apparatus through an outlet provided in the third booth. The coating film layer is configured to be more uniformly thinned by the operation of the blower and by the force of the air flow discharged from the third booth in a pressurized state to the outside. The coating device for a building member according to claim 1. 10. The building member coating apparatus according to claim 9, wherein the carry-out port provided in the third booth has at least a ceiling or an eave having a predetermined length in depth. . 11. The ceiling or eaves of the carry-out exit, wherein the whole or part of the ceiling or eaves in the depth direction has a descending slope from the third booth side toward the outside. Item 11. An apparatus for coating a building member according to Item 10. 12. A method for coating a building member using the coating apparatus according to claim 1, wherein the object to be coated as the building member is placed on the conveyor, A first booth, a second booth, and a third booth are sequentially passed. In the first booth, a liquid coating layer is formed by spraying a paint on the surface of the workpiece by the spray coating unit, In the second booth, the blower is operated to make the inside of the second booth under reduced pressure, and the liquid coating layer formed on the surface of the workpiece is defoamed. In the third booth, Operating the blower and blowing air to the liquid coating layer formed on the surface of the object to be coated, so that the inside of the third booth is in a pressurized state, and the second booth and the third Through the opening for the air knife between the booth of Air was flowed from the booth No. 3 to the second booth, and due to the flow of the air, the object to be coated was placed on the conveyor and formed on the surface thereof when passing through the air knife opening. A coating method for a building member, wherein the liquid coating layer is thinned substantially uniformly. 13. The liquid coating layer formed on the surface of the object to be coated when the object to be coated is carried out through an outlet provided in the third booth to the outside. The thin film is further uniformly thinned by the flow of air discharged from the third booth in a pressurized state to the outside through the carry-out port by the operation of the blower. 13. The method for coating a building member according to item 12. 14. The coating of a building member according to claim 12, wherein the building member to be coated is an outer wall material having a surface provided with an embossed pattern, a concave portion, a convex portion or a groove portion. Method. 15. The method according to claim 14, wherein the outer wall material is an ALC or a hard wood chip cement board. 16. The method for coating a building member according to claim 12, wherein the building member to be coated is an accessory.