JP2550786Y2 - Electrostatic coating equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic coating apparatus for applying a photoresist or the like to a surface of an object to be coated such as a printed circuit board.

[0002]

2. Description of the Related Art The application of a photoresist by an electrostatic coating method can form a uniform film and does not block a through hole of a substrate with the photoresist as compared with a roll coater method or a screen printing method. Widely used.

[0003] An apparatus for performing such electrostatic coating has a structure in which a spray gun is disposed at an upper portion in a coating booth and an earth plate is disposed at a lower portion, and a transport belt (paper belt) runs directly above the earth plate. The paint particles ejected from the spray gun are negatively charged, so that the paint particles are attracted to the ground plate, and adhere to the surface of the object to be coated that passes directly above the ground plate together with the transport belt. Like that.

[0004]

According to the above-mentioned electrostatic coating method, since the paint particles are attracted to the ground plate, the spread in the lateral direction is suppressed to some extent. Float, and adhere to the inside wall of the booth. Then, another paint particle adheres to the paint particles adhered to the inner wall surface of the booth, and is further dried and separated as a large lump, and the lump falls on the surface of the object to be coated and causes defective products. In order to avoid this, in the past, the inside of the booth had to be frequently cleaned, and the operation was stopped each time, and the cleaning work was also troublesome.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method in which a sheet having an air cap formed on an inner wall surface of an electrostatic coating apparatus (hereinafter, referred to as an "air cap sheet") is provided in the booth. It was detachably attached to face.

[0006]

[Function] If the device of the present invention is used, since the air cap sheet adhered to the inner wall surface of the painting booth is negatively charged in a large area, the paint particles ejected from the spray gun and negatively charged are air cap sheet. The repelled paint particles efficiently adhere to the surface of the object to be coated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a front view of the electrostatic coating apparatus according to the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of the electrostatic coating apparatus. 2 and an outlet 3 are formed, and a paper belt 4 for conveyance is provided between the inlet 2 and the outlet 3.

The paper belt 4 travels from an unwinding roll 5 equipped with a brake mechanism to a winding roll 6 which is rotated by a motor.
Is transported from the inlet 2 to the outlet 3.

The coating booth 1 is provided with a window 7, and a rotary cup type spray gun 8 is disposed at a position visible through the window 7. The spray gun 8 is attached to the lower end of a cylinder unit 10 that reciprocates along a rail 9 in the width direction orthogonal to the running direction of the paper belt 4. Is provided with an electrode 12 for negatively charging.

On the other hand, an earth plate 13 is arranged on the back side of the paper belt 4 below the spray gun 8, and an exhaust blower 14 is provided at the bottom of the coating booth 1.

Further, an air cap sheet 15 is attached to the inner wall surface (including the window portion 7) of the coating booth 1 as shown in FIG. The air cap sheet 15 is made of an easily charged material such as polyethylene which has not been subjected to an antistatic treatment. The side to be attached to the inner wall surface of the coating booth 1 has a flat surface, and the surface on which the air cap 16 is formed is the coating booth 1. Is turned inward.

Incidentally, the air cap sheet 15 is attached not only to the inner wall surface of the coating booth 1 but also to various places. This makes replacement easier. Further, the air cap sheet 15 may be stuck twice on the inner wall surface of the painting booth 1. In this way, the air cap sheet 15 can be replaced with a new one simply by peeling it off.

In the above, negatively charged paint particles 11 are ejected from the spray gun 8. Then, paint particles 1
.. Flow downward by the air current and electrostatically converge toward the ground plate 13. On the other hand, at this time, when the object to be coated W is placed on the paper belt 4 and conveyed from the inlet 2 to the outlet 3, it passes through the paint particles, and the paint particles 11 adhere to the surface of the object to be coated W. To form a uniform coating.

In the above-mentioned coating step, a large amount of paint particles 11 are suspended in the booth 1.
6, some adhere to the surface, but most are repelled and adhere to the object to be coated. Then, after the operation for a predetermined time, the number of paint particles adhering to the air cap sheet 15 increases, and the repulsion efficiency of the paint particles decreases. Therefore, the operation is stopped once, the dirty air cap sheet 15 is peeled off, and a new air cap sheet 15 Paste.

[0015]

[Effects of the Invention] As described above, according to the present invention,
Since the air cap sheet is detachably attached to the inner surface of the electrostatic coating device, not only can the paint particles be efficiently and uniformly adhered to the surface of the object to be coated without waste, but also the air cap sheet is simply peeled off. It is not necessary to clean the inside wall of the booth just by replacing it, especially by attaching the air cap of the air cap sheet toward the inside of the booth, the surface area of the air cap sheet increases, repelling a large amount of paint particles As a result, the coating efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of an electrostatic coating apparatus according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the electrostatic coating apparatus.

[Explanation of symbols]

1 ... Painting booth, 4 ... Paper belt, 7 ... Window, 8 ...
Spray gun, 10: cylinder unit, 11: paint particles, 13: ground plate, 15: air cap sheet, 16
… Air cap.

Claims (3)

(57) [Scope of request for utility model registration] 1. An electrostatic coating apparatus in which paint particles ejected from a spray gun disposed in a coating booth are negatively charged and negatively charged paint particles are adhered to a surface of an object to be coated. An electrostatic coating apparatus, wherein a sheet having a flat surface on one side and a number of air caps formed on the other surface is detachably attached to the inner wall surface such that the air cap faces the inside of the booth. 2. The electrostatic device according to claim 1, wherein a transporting belt on which the object to be coated is mounted and traveling is disposed in the coating booth, and an earth plate is disposed immediately below the transporting belt. Painting equipment. 3. The electrostatic coating apparatus according to claim 1, wherein the spray gun is movable in the air toward a ground plate.