JPS5920390B2 - Centrifugal electrostatic coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a rotating disk-type centrifugal electrostatic coating device using solution coating.

As a conventional device of this type, one is known that is configured so that a solution paint is supplied to the center of a rotating disk and the paint is dispersed and atomized only by the centrifugal force of the rotating disk.

Equipment with this kind of structure had no problems with solution paints with a solid content of up to 40%, but as a pollution control measure under the Air Pollution Control Ordinance, such as the emission control of organic solvents, the solid content must be 65% or more.
As the use of high-solid paints such as 0%, 75%, 80%, etc. became required, the paint finish of conventional methods deteriorated, causing paint bubbles and pins during painting. Problems such as holes, poor leveling, poor surface finish, and foaming in the corners had occurred, and it was important to improve the coating equipment. (Fundamentally, it has become extremely difficult to apply atomized atomization using conventional methods due to the increase in solids content and the inclusion of high-boiling point solvents, so the development of a dedicated coating machine was desired.) In the present invention, a conical cylinder for centrifugally reducing the viscosity of solution paint is attached to the upper surface of the central part of a conventional rotating disk, and a large number of concentric grooves are formed on the outer surface of this cylinder, and the rotating disk is rotated at high speed (
1000~4000rp□)
By doing this, the paint that comes out of the solution paint supply section in the center of the disk is agitated at high speed inside the conical tube, and the centrifugal force degasses it and reduces the viscosity. The paint that overflows due to the centrifugal force flows out from the outlet of the conical tube and rotates on the outer surface of the groove on the slope, and is further finely cut and reaches the top surface of the disc, where it is further removed by the centrifugal force of the high-speed rotation. It is possible to obtain a centrifugal electrostatic coating device that has very good coating conditions in which the particles are atomized and the viscosity is reduced not only by temperature but also by kinematic viscosity.

The present invention will be explained in detail below according to an embodiment shown in the drawings.

FIG. 1 is a schematic cross-sectional view of a centrifugal electrostatic coating device that is an embodiment of the present invention, FIG. 2 is a cross-sectional view of important parts of the upper part of the coating device of the present invention, and FIG. 3 is a top view of FIG. FIG. 4 is a sectional view of a main part of another embodiment of the centrifugal electrostatic coating apparatus of the present invention.

As shown in FIG. 1, the centrifugal electrostatic coating device has a centrifugal electrostatic coating discharge section 2 attached to the head portion of a regipro shaft 1 (hereinafter simply referred to as shaft 1).

The shaft 1 is provided with a paint supply port 3 that is fed by a three-way cock, and is connected to a paint supply pipe 4. The upper end of the pipe 4 is installed in a conical tube 8 attached to the center of the rotary disk 6 and its upper part, and serves as an outlet 1. The rotating body of the rotating disk 6 and the conical cylinder 8 is an electric motor 1.
It is also connected to the upper part of the second cylindrical rotor 9 with fixing fittings 13, 14 and an angle jig part 15. The rotor 9 is mounted on the supply pipe 4 and rotates in relation to a stator coil 10 fixed to the casing 11. The structure of the rotating disk 6 and the conical cylinder 8 is as shown in FIG. 8 inside 16
The conical tube 8, which is configured to be installed inside the tube, has a large number of concentric helical chevron-shaped grooves 18 formed on the outer surface of its inclined portion 17.

The upper part of the inclined part 17 is cylindrically extended by several tens of mm to form a cylindrical part 19 to prevent scattering due to the centrifugal force inside the conical cylinder 8. The paint is reduced in viscosity and degassed by the centrifugal force discharged from the conical tube 8, even if it is a high-solids paint that has a high solid content with a slightly high viscosity. 20, is further cut by the concentric helical chevron groove 18, reaches the top of the rotating disk 6, is further made fine, is exposed from the tip 21 of the disk 6, becomes ultra-fine paint charged by static electricity, and is applied to the object to be coated. It is attached. Even with high-solids paints, if the solids content is 65% or more and it becomes 70% or 80%, it means that the organic solvent content is low, and the amount that sticks to the ceiling of the painting room falls off after several hours of operation due to the high boiling point solvent content. To avoid the risk of dripping onto the object to be coated or the top surface of the centrifugal electrostatic coating device due to the stringing phenomenon, a conical tube 8 with the cylindrical portion 19 removed, as shown in FIG. installed on,
A circular funnel-shaped jig 22 is fixedly screwed to the outlet 7 of the paint supply pipe 4 by forming a screw thread in the direction opposite to the rotation at its shaft pipe portion 23. The shaft pipe portion 23 may also be formed with a delivery hole 24a for delivering the fluid into the interior 16 of the conical tube 8. As a result of this operation, the paint flowing out from the inside 16 of the conical container 8 due to centrifugal force flows into the groove 1 in the same manner as described above.
9→disk 6→tip part 21, and is exposed and scattered. The exposed paint scattered from the tip 21 of the disk 6 is prevented by the jig 22 from being agitated at the upper end of the vertical movement of the shaft 1 and moving toward the ceiling due to the addition of electrostatic force. Then, it goes around to the upper part 25 of the lower part 24 of the jig 22, and the dripping amount is moved in the direction of the arrow mark so that it can be collected into the inlet 26 of the jig 22 and the inside 16 of the conical tube 8. .

The angle θ of the jig 22 with respect to the horizontal is set to 90 so that it can be recovered.
It is designed within the range of 45 tools. The collected amount is uniformly mixed with the paint from the discharge hole 24 in the pocket 16 inside the conical tube 8 to achieve an ideal coating viscosity and atomized, and is atomized from the tip 21 of the disk 6. It is.
The outer diameter of the jig 22 should be appropriately larger than the diameter of the disk 6, which is a divisor of the diameter. Big eyes are good. Further, as shown in FIGS. 4 and 2, stirring blades may be installed in the interior 16 of the conical tube 8, in the tube 8 or in the tube portion 19 of the jig 22, so as to further promote a reduction in kinematic viscosity. Further, in the above-described embodiment, high-speed rotation by an electric motor may be achieved by an air motor. Further, the spiral groove 18 of the inclined portion may be shaped into a blade and cut into a fine grain by using steel for blades.

As described above, according to the centrifugal electrostatic coating apparatus of the present invention, the paint supplied to the disc part is subjected to low viscosity fluidity and centrifugal defoaming by the conical cylinder, and the paint is coated on the outer peripheral surface of the paint. Since it is centrifugally divided into fine particles in the grooves and then finely discharged on a rotating disk, the high-speed rotation of 1800 rpm compared to the conventional method is possible. However, high-solid paints can be applied easily and with a good finish under hot paint conditions at room temperature of 20 to 60°C.

In addition, by simply modifying the conventionally used centrifugal electrostatic coating equipment with a high-speed rotating disc, a high solids coating layer with a high solids content can be used over a wide range of areas, eliminating the need to install new coating equipment and reducing capital investment. Not only can the amount be reduced, but also the coating effect can be further improved.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a centrifugal electrostatic coating device that is an embodiment of the present invention, FIG. 2 is a cross-sectional view of important parts of the upper part of the coating device of the present invention, and FIG. 3 is a top view of FIG. FIG. 4 is a sectional view of a main part of another embodiment of the centrifugal electrostatic coating apparatus of the present invention. 3 is a paint supply port, 6 is a rotating disk, 8 is a conical cylinder, 18 is a groove, and 20 is a discharge port.

Claims (1)

[Claims] 1. In a centrifugal electrostatic coating device configured to supply a solution paint onto a rotating disk through a solution paint supply section formed in the center of the rotating disk and atomize the solution paint,
A conical tube is installed to cover the solution paint supply section, and a large number of concentric grooves are formed on the outer peripheral surface of the conical tube, and a discharge port is formed at the top of the conical tube. Centrifugal electrostatic coating equipment.