JPH0657333B2 - Coating equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coating apparatus, and more particularly to a coating apparatus capable of continuously and satisfactorily coating a desired thickness regardless of the surface properties of an object to be coated.

[Problems to be Solved by Conventional Technology and Invention] Conventionally, various types of devices have been proposed as a device for continuously coating an object to be coated on a conveyor in a mass production plant. A curtain flow coater, a shower coater, a mist spray coater or the like is used for coating.

However, in these coating apparatuses, since the coating film thickness changes according to the transport speed of the object to be coated, it is necessary to accurately control the transport speed in order to obtain a coating film having a constant thickness. Further, since the coating material is supplied uniformly over the entire surface regardless of the surface condition of the coating object, the coating film thickness may become uneven when the surface properties of the coating object (for example, paint absorption) are partially different. In some cases, the coating film thickness may change depending on the difference in surface properties of the object to be coated even under the same coating conditions, and it may not be possible to maintain a desired film thickness accuracy. This is particularly remarkable when a porous member such as slate, concrete, wood or ceramic is used as the object to be coated.

Therefore, an object of the present invention is to provide a coating apparatus which does not have the above-mentioned problems of the prior art and can be easily coated to a desired thickness regardless of the surface properties of the object to be coated.

[Means for Solving the Problems] According to the present invention, an object as described above is to apply a coating material to an object to be coated, and to remove an excessive amount of the coating material from the applied object to be coated. And a means for transporting an object to be coated from the coating section via the film thickness adjusting section, the film thickness adjusting section being a casing and the inside of the casing. And a means for depressurizing the inside of the casing, and an opening of an inlet for an article to be coated and an opening for an outlet of the article to be coated. Is formed to include a shutter having these openings, and an outlet for an object to be coated of the casing has a shape in which an appropriate slight gap is formed between the object to be coated and the coating surface of the object to be coated. And a direction in which the gas blowing means traverses the conveyance direction of the article to be coated. Characterized in that it is reciprocally moved, painting device, is achieved by.

In the present invention, the coating material inlet of the casing has a shape structure in which an appropriate slight gap is formed between the coating material coating surface of the coating material and the coating material coating surface when the coating material passes through the casing. be able to.

In the present invention, the paint mist collecting means may be arranged at the connecting portion between the casing and the means for reducing the pressure inside the casing.

In the present invention, means for removing the coating material adhering to the article-to-be-coated conveying means in the coating section may be provided.

In the present invention, the means for reducing the pressure inside the casing may be connected to the gas blowing means.

In the present invention, it is assumed that the casing is provided with means for covering the unpainted portion of the article to be coated when the article to be coated passes along the article conveying direction from the article inlet to the article outlet. be able to.

[Examples] Specific examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of a coating apparatus according to the present invention. In this example, the object to be coated is a plate-shaped body and the upper surface of the plate-shaped body is uniformly coated.

In the figure, 2 and 4 are conveyors that constitute the article-to-be-conveyed means and can convey the article-to-be-coated M in the direction of arrow A. As these conveyors, for example, a chain conveyor or a belt conveyor can be used.

Reference numeral 6 is a coating material application unit arranged above the conveyor 2. As the coating means, for example, a 2-slit type curtain flow coater, a 1-slit type curtain flow coater, an overflow type curtain flow coater, a shower coater, a mist spray coater or the like can be used. The conveyor 2 runs through a cleaning solvent tank 8 arranged below, and a solvent 10 for dissolving and removing the paint adhering to the conveyor chain is contained in the tank. . Reference numeral 12 denotes a roll brush arranged in the solvent tank 8, which comes into contact with the conveyor chain and is driven and rotated to physically remove the paint adhering to the chain.

An application unit is configured to include the conveyor 2 and the application unit 6.

Reference numeral 14 denotes a casing, which is disposed between the conveyor 2 and the conveyor 4 and has an inlet 16 to which the article M to be coated is supplied by the conveyor 2 and the conveyor 4
An outlet 18 through which the article M to be coated is discharged is provided. Further, a vertically movable shutter 20 capable of limiting the opening shape of the inlet 16 by the lower end edge and closing the inlet is attached to the casing 14 above the inlet, and A vertically movable shutter 22 capable of limiting the opening shape of the outlet 18 and closing the outlet is mounted above the outlet.

Inside the casing 14, a nozzle 24 is provided for blowing compressed air onto the upper surface of the article M to be conveyed. The nozzle is reciprocally movable by a reciprocator 26 in a horizontal direction (B direction) orthogonal to the A direction.
28 is a blower for sending compressed air to the nozzle,
A pipe 30 partially having a flexible portion is connected to the nozzle 24 in the casing.

A blower 32 as a means for reducing the pressure inside is connected to the casing 14, and the paint mist collecting filter is connected to the casing 14 at the connecting portion so as to block the gas flow path when exhausted by the blower 32. 34 are arranged. 36 is a tank for recovering the paint collected by the filter. Further, 38 and 40 are baffle plates.

A seal plate 42 is arranged in the casing 14 along the lower side of the conveyance path of the article M to be coated.

A film thickness adjusting unit is configured including the casing 14 to the seal plate 42.

Reference numeral 44 is a sensor for detecting the article M to be coated which is conveyed on the conveyor 2.

FIG. 2 is a partially sectional front view of the casing 14 in the vicinity of the outlet of the article to be coated according to the present embodiment.

In the figure, reference numeral 46 designates an opening setting member which can be laterally positioned to limit the right side of the opening of the outlet 18 of the casing 14, and although not shown, a similar opening setting member is also arranged on the left side. ing. When the object M to be coated is a plate-like object and the upper surface of the plate-like object is evenly coated, when the object to be coated M passes through the outlet 18, it is located exactly in the center of the opening of the outlet and is covered with the opening. The lateral position of the opening setting member 46 and the vertical position of the shutter 22 are set so that the gap 50 between the upper and lower surfaces of the coating material M and the left and right end surfaces is, for example, 1 to 5 mm. However, the above-mentioned gap can be appropriately changed according to the degree of pressure reduction in the casing 14 and the like.

In the seal plate 42, a shallow concave portion is formed in a portion facing the lower surface of the object M to be coated along the object conveying direction (direction A). The depth of the recess is, for example, about 3 to 7 mm. However, the width of the concave portion is slightly smaller than the width of the article M to be coated, and thus the article M is completely covered in the width direction.

Although the vicinity of the outlet 18 has been described above, the vicinity of the inlet 16 is similar to the vicinity of the outlet.

Next, the operation of the coating apparatus of this embodiment will be described.

In the coating section, the article M is conveyed on the conveyor 2 in the A direction, and the coating means 6 coats an excessive amount of coating material on the upper surface.

On the other hand, in the film thickness adjusting unit, first, the inlets 16 and the outlets 18 are moved downward to close the shutters 20 and 22, respectively, and the blowers 28 are operated while the casing 14 is depressurized by the blowers 32. Let the nozzle 2
Compressed air is discharged from 4. The velocity of the discharged air is, for example, 100 to 150 m / sec. The amount of air discharged from the nozzle is, for example, 2 to 4 times the amount of air discharged to the outside of the casing 14 by the blower 32. The blower 28 can be omitted by supplying a part of the air exhausted by the blower 32 to the nozzle 24.

Then, in the coating section, the object M to which the coating is applied is applied.
When the head of the shutter is detected by the sensor 44, the shutter 2
0 is moved upward to form a predetermined inlet opening shape,
The article M to be coated is supplied into the casing 14 through the opening.

FIG. 3 (a) shows the distribution of the coating material 52 applied to the object M to be coated in the coating section, and FIG. 3 (b) shows the partially different coating material absorption characteristics of the object M to be coated. It shows the coating film thickness distribution when it reaches the casing 14 in the case of holding. Here, a case is shown in which the central portion of the article to be coated M has high paint absorbency and both ends have low paint absorbency. That is, the coating material 52 is absorbed according to the coating material absorption characteristics of the object M to be coated in a predetermined time after application, and the coating film thickness is thin in the central portion and thick in both end portions.

FIG. 4 (a) is a sectional view showing a state in which the article M to be coated is brought close to the inlet of the casing 14 in such a state, and FIG. 4 (b) shows the article M to be coated from the inlet opening. FIG. 5 is a cross-sectional view showing a state in which the supply into the casing 14 has started.

Since the inside of the casing 14 is depressurized, the outside airflow flows from outside the casing through the inlet opening, and thus a part of the excess paint of the paint 52 applied to the upper surface of the object M is stripped by the airflow. It becomes a mist and is sucked into the casing 14. At this time, the lower surface of the article M to be coated is always covered with the seal plate 42 in the casing 14, and the airflow flowing from the outside of the casing 14 always flows along the lower surface of the article to be coated. Does not reach the lower surface of the article to be coated, and therefore the paint does not adhere to the lower surface of the article to be coated.

FIG. 5 is a sectional view showing the operation of the nozzle 24 in the casing 14.

At the tip of the nozzle 24, three long slits are formed in the direction A, which are oriented in different directions, and compressed air is discharged from the slits. Since the nozzle 24 is reciprocally moved in the B direction, even in the case of the object M to be coated having an uneven surface, compressed air is effectively blown to the recess from different angles to remove a part of the excess paint. The coating film thickness can be made constant.

Then, after a lapse of a predetermined time from the detection of the head of the article to be coated by the sensor 44, the shutter 22 is moved upward to form a predetermined outlet opening shape, and the article to be coated M is fed from the opening to the casing 1
4 Discharge to the outside.

FIG. 6 is a sectional view showing a state in which the article M to be coated exits the casing 14.

When the article M to be coated passes through the opening of the outlet 18, the inside of the casing 14 is depressurized, so that the paint 52 applied to the opening and the upper surface of the article M to be coated by the external airflow flowing from the outside of the casing. Excess paint (including excess mist sucked into the casing 14 and paint mist scattered in the casing by blowing compressed air from the nozzle 24 in the excess paint. Are removed and sucked into the casing 14. Thus, a coating film having a desired constant thickness is formed on the article M to be coated discharged from the casing 14.

The paint mist in the casing 14 is collected by the filter 34 as the blower 32 exhausts the air, and the tank 3 is used as needed.
It is collected in 6 and reused if necessary.

By setting the positions of the shutters 20 and 22 so that the entrance opening of the casing 14 is slightly larger than the exit opening, it is possible to prevent the paint suction load at the entrance from becoming excessive.

Each of the shutters 20 and 22 is moved downward after a predetermined time from the detection of the rearmost end of the article M by the sensor 44, and the inlet opening and the outlet opening are closed. The time of movement of the shutters 20 and 22 is appropriately set according to the transport speed of the article M to be coated.

[Effects of the Invention] As described in detail above, according to the coating apparatus of the present invention,
By applying an excess amount of paint to the object to be coated in the coating section and then removing the excess amount of the coating material in the film thickness adjusting section, it is possible to easily achieve a desired thickness regardless of the surface properties of the object to be coated. Can be painted. Further, the paint mist does not leak to the outside from the film thickness adjusting section, which is hygienic.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a coating apparatus according to the present invention. FIG. 2 is a partially sectional front view of the casing of the coating apparatus according to the present invention in the vicinity of the article outlet. FIG. 3 (a) shows the distribution of the coating material applied to the object to be coated in the coating portion, and FIG. 3 (b) shows the case where the object has partially different coating material absorption characteristics. It shows the thickness distribution of the coating film when it reaches the casing. 4 (a), (b), FIG. 5 and FIG. 6 are sectional views for explaining the operation of the coating apparatus according to the present invention. 2, 4: Conveyor, 6: Coating means 8: Washing solvent tank, 14: Casing, 16: Inlet, 18: Outlet, 20, 22: Shutter, 24: Nozzle, 26: Reciprocator, 28, 32: Blower, 34 : Filter, 42: Seal plate, 44: Object detection sensor, 52: Paint.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-58-128164 (JP, A) JP-A-62-183874 (JP, A) JP-A-55-141578 (JP, A) Actual development Sho-58- 146574 (JP, U) Actual development Sho 52-127050 (JP, U)

Claims (3)

[Claims] 1. A coating part for applying a coating material to a coating object, and a film thickness adjusting part for removing an excessive coating material from the coated coating material to obtain a desired coating film thickness. Means for transporting the article to be coated via the film thickness adjusting section is arranged, and the film thickness adjusting section blows gas to the casing and the coating surface of the article to be coated which is transported in the casing. And a means for decompressing the inside of the casing, the opening of the article inlet and the article outlet of the casing are formed to include the shutter of these openings, the casing The outlet of the article to be coated has a shape structure in which an appropriate slight gap is formed between the article to be coated and the coating surface of the article to be coated when the article to be coated is passed. A coating device characterized by being able to reciprocate in a direction transverse to the transport direction. 2. The coating apparatus according to claim 1, wherein a paint mist collecting means is arranged at a connecting portion between the casing and a means for reducing the pressure inside the casing. 3. The coating apparatus according to claim 1, wherein the means for reducing the pressure inside the casing is connected to the gas spraying means.