JPS5884076A - Powder electrostatic coater - Google Patents

Abstract

PURPOSE:To form uniform paint films on sheet materials by dropping powder paint on a flow regulating plate by means of a powder fluidizing tank and a roller, then applying electrostatic charge and sprinkling the paint uniformly over the entire surface. CONSTITUTION:The powder in a powder chamber 6 is fluidized by the air permeated through a perforated plate 4 from an air chamber 8. The fluidized powder is dropped downward through a slit 5 and is accumulated in a hopper 14. Thereafter, the powder in a hopper 14 is discharged through a clearance 23 by the revolution of a roller 21 and is dropped down onto the top end part of an inclined flow regulating plate 24 consisting of a perforated plate. The dropped powder is charged electrostatically while passing between a pair of electrodes 30 and 31 applied with -40--90KV. The powder is sprinkled uniformly onto a sheet which is placed on a conveyor 32 and moves, whereby the powder is stuck thereon electrically. The powder is baked to form a paint film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic powder coating machine, and more particularly to a coating machine capable of forming a thin coating film of uniform thickness at high speed.

In recent years, the so-called pre-coat method, in which steel plates and other materials are coated before bending and other processing steps, has become popular in the production of home appliances and other products due to its energy savings and productivity improvements. There is. By the way, in the case of the pre-coating method, the processing of the board material is carried out after painting, so the coating must be formed thin and at high speed to a uniform thickness to prevent damage such as cracks to the coating during processing. Painting machines with such performance are desired.・This invention can meet the above-mentioned needs by providing a method for forming a thin and uniform coating film at high speed on sheet materials such as steel plates, paper, cloth, and combs to which the pre-coating method can be applied. The purpose is to provide a powder electrostatic coating machine that can.

Hereinafter, the present invention will be specifically explained with reference to illustrated embodiments. In this specification, the front and back relationship is based on FIG. 1, and the right side of the figure is referred to as the front, and the left side is referred to as the rear.

In Figures 1 and 2, +11+21 is a pair of left and right side plates of the powder electrostatic coating machine according to the present invention, and (3) is a powder fluidization tank provided at the rear of the top between the pair of side plates (11+21). This is equipped with a horizontal perforated plate (4) at the bottom for air permeation.Thus, this perforated plate (41) allows the powder flow tank (3) to have a horizontal perforated plate (4) at the top of the front wall for powder outflow. slit(
5), an open upper powder chamber (6), and an air conduit (7).
It is divided into a lower air chamber (8) connected to the lower air chamber (8). The opening width of the slit (5) is adjusted by vertical movement of the adjustment plate (9). The same kind of noise (
3) An upper support plate provided horizontally at the lower end position, at the rear of which is opened an upper rectangular hole αD that is long in the left-right direction.
ing. ＠ is a lower support plate provided horizontally across the side plates (11 and 21) at approximately the center of the height. +141 is a hopper with an inverted eight-shaped cross section installed horizontally between the upper and lower support plates aαQ2;
9, a rear wall α, and a pair of left and right end walls αηα.

The upper end of the front wall α9 is attached to the lower surface of the upper support plate αG,
The lower part α9 of cohabitation (2) can be freely swung back and forth by a hinge ■. In addition, the upper end of the rear wall (161) is attached to the lower front part of the powder fluidization tank (3), and the lower end of the coexisting αe is attached to the upper surface of the lower support plate.
The powder flowing out from the slit (5) is passed through the upper rectangular hole αυ.
It has been made to be accepted through. C1l+ is rotated below the front wall α9 and in the lower rectangle. Also Laura (
2) is the powder discharge gap (to) between the front wall and the lower part α
It is located so as to form a The width of the gap can be adjusted by adjusting the angle of the swinging lower part α9 of the front wall α9.

Further, the rear end of the roller (21) is in close contact with the lower end of the rear wall αe of the hopper αΦ to prevent leakage of powder. (Incorporated) is a porous pipe for air supply arranged at the bottom of the hopper α station in parallel with Rolla (Inc.), and this has an air conduit device. The perforated tube fluidizes the powder within the 40 tubes and prevents the powder from turning into a liquid when pressure is detected at the bottom. Also, depending on the type of powder coating, other means such as a baffle board may be installed in the hopper α in addition to the perforated pipe. ＠ is a powder straightening plate arranged in an inclined manner below Roller Co., Ltd., and this is attached to the lower support plate ＠ via a mounting rod (5). The current plate (E) is composed of a perforated plate made of insulating material, and an air chamber (2) is provided on the back side of the plate, and an air conduit (2) is connected to the bottom of the chamber (2). ■0υ is a pair of linear high-voltage electrodes -V placed below the rectifying plate ■.

These are positioned so as to sandwich the powder flowing down from the current plate (2) from both the front and back sides.

The powder electrostatic coating machine is configured like this.

It is arranged on a slat conveyor (to) that conveys plate-shaped objects to be coated, and its side plates 111+21 are attached to the side frames (to) of the conveyor (2). The powder in the powder chamber (6) is kept in a fluid state by air passing through the perforated plate (4) from the air chamber (8). This flows down from the slit (5) and is received in the hopper (141) where it is stored.The powder in the hopper aa is also made into a fluid state by the air passing through the porous pipe (to). As a result, the amount of powder stored is uniform over the entire length of hopper α0.Then, hopper Q41
The powder inside is discharged from the gap (c) by the rotation of the rollers, and flows down to the upper end of the inclined current plate (2) made of a perforated plate.

In the example of a porous rectifier plate, air is transmitted from the air chamber (support) on the back side to the front side, so the powder does not adhere to the rectifier plate (a) and is moved horizontally over the plate. Flows down at a uniform flow rate over the entire length. The flow rate can be changed as appropriate in the range of 300 F/min to 5 KgZ by adjusting the rotation speed of the rollers and the spacer. The powder flowing down on the rectifying plate ■ is connected to a pair of electrodes ■ (9) where a voltage of -40 to -g□KV is applied.
becomes electrically charged while passing through an electric field caused by This is then uniformly poured over the entire surface of the plate-shaped object placed on the conveyor 1 and moving along with it, and is electrically adhered thereto. After that, baking is performed. In this way, the powder electrostatic coating is applied to the plate material.

The coating machine according to this invention is configured as described above.
A powder delivery roller (2) is placed below the front wall αS of the hopper αΦ.
The hopper is installed to form a powder discharge gap between the hopper and the hopper, and a porous pipe for air supply is placed at the bottom of the hopper in parallel to the rollers. Therefore, the powder in the hopper αΦ flowing down from the powder fluidization tank (3) is brought into a fluidized state by the air passing through the perforated pipe, and as a result, the amount of powder stored in the hopper aO is , the powder is uniform over the entire length of the hopper αa, and the powder is discharged little by little at a uniform flow rate over the entire length from the gap by the rotation of the roller, forming a thin layer that is uniform over the entire surface of the object to be coated. The rain is burned n1. Thus, according to the coating machine of the present invention, a thin coating film of uniform thickness can be formed on a plate at high speed.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. gJ1 is a partially cutaway side view of the coating machine, and FIG. 2 is a partially cutaway sectional view taken along line 1--2 in FIG. +1+ +2+...Side plate, (3)...Powder fluidized bed,
(4)...Perforated plate, (5)...Horizontal slit), 16
1... Powder chamber, (7)... Air conduit, (8)...
Air chamber, (9)・Fist・Adjustment board, αe0・Upper support plate, α
D... Upper rectangular hole, (2)... Lower support plate, Q31
... lower rectangular hole, α0 ... hole, f, αBO / front wall, αe - - rear wall, α ri αε ... end wall, al ...
Lower part, ■...Hinge, Co., Ltd....Roller, ■...
・Motor, (c)...gap, (goods)...porous pipe, (
2)... Air conduit, (a)... Rectifier plate, gradient...
Mounting frame, ■...Air chamber, (2)...Air conduit, ■(
9)... Electrode, @... Conveyor, c13c31J.
・Side frame. Applicant for the above patent: 4 people including Kubo Takashi Paint Co., Ltd. Figure 2

Claims (1)

[Claims] A powder fluidization tank (3) provided at the top between a pair of side plates (11+21) and equipped with a perforated plate (4) for air permeation;
The same type (3) installed horizontally below the fluidized tank (3)
A powder discharge chamber 11j (2) is formed between the hopper Q41, which has an inverted eight-shaped cross section and receives the powder flowing down from the slit (5), and the coexisting α9 below the front wall a9 of the hopper α. A powder delivery roller (21) provided to convey the powder, a porous pipe for air supply arranged at the bottom of the hollow #0 so as to be parallel to the roller (21), and the roller (21). (
Powder electrostatic coating consisting of a powder rectifying base arranged in an inclined manner below the rectifying plate, and a pair of electrodes C11 arranged below the same rectifying plate so as to sandwich the falling powder from both sides. Machine.