JPS62294463A - Apparatus for continuously applying powder to metal material - Google Patents

Abstract

PURPOSE:To apply powder paint to the entire surface of a metal material uniformly and continuously, in a painting apparatus using a fluidized immersion method, by providing a shield plate having a notch part and a shield part at a position spaced apart from the metal material in a fluidized tank. CONSTITUTION:Air in an air chamber 2 supplied by a blower (b) is allowed to pass through a porous body 3 and mixed with the synthetic resin powder (a) in a fluidized tank 4 having said powder received therein to form a fluidized bed. At this time, a shield plate 10 partially preventing the rising stream of the fluidized bed is provided so as to leave a predetermined distance from the under surface of the wire or rod-shaped metal material 5 passing through the fluidized tank 4 and, therefore, a strong part and weak part are alternately generated in the rising stream by the shield part 9 and notch part 10 of the shield plate 10 and, as a result, the generation of a pinhole due to the fusion deficiency on the under surface of the metal material 5 can be prevented.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is a method of coating a metal material, such as a long wire rod or a long bar material, with a synthetic resin and placing it in concrete. This invention relates to a continuous powder coating device for metal materials that is powder coated for the purpose of making it slippery when installed inside or for the purpose of rust prevention.

(Prior Art) As a method for coating metal materials such as long wire rods and long rods with synthetic resins, fluid dipping methods, fluid circulation methods, etc. are conventionally often used.

Conventionally, as shown in FIG. 6, a porous body 3 is installed between an air chamber 2 that blows air through a wire-shaped metal material 1, which is a preheated raw material, and a powder fluidization tank 4, as a device for implementing the conventional fluidized dipping method. is provided, and a blower b for blowing air is connected to the air chamber 2.
A long wire metal material 1 is inserted through the inlet 6 into a mixed fluidized bed of air and synthetic resin powder, and is allowed to escape from the outlet lower.
This is a device that sprays synthetic resin onto the surface of the plastic. Although this conventional device has the advantages of a simple structure, easy handling, and low equipment cost, the coating film of the synthetic resin powder is uneven and pinhole defects are likely to occur. There are drawbacks. As shown in FIG. 7, when the air that has passed through the air chamber 2 and the porous body 3 blows the synthetic resin powder forming a fluidized bed toward the metal material 5, the fluidized bed rises. Although the flowing powder is sprayed on both sides of the metal material 50, the lower surface becomes a blind spot 15, and since the amount of synthetic resin powder a adheres to this part is small, the coating film becomes uneven.

In addition, pinholes occur, and this tendency becomes more severe as the wire diameter of the metal material increases.

As shown in FIG. 8, the apparatus for carrying out the fluidized bed circulation method includes a porous body 3 provided in an air chamber 2 equipped with a blower b, and a coating powder fluidization tank 4 provided above the porous body 3. A flow path 16 provided in the fluidization tank 4 is connected to one end of a coating header 17, a metal material 5 such as a wire rod is passed through the coating header 17, and synthetic resin powder is sprayed and painted.
A flow path 18 provided at the other end of the coating header 17 is connected to the fluidized bed 4 via a tank 19 in the middle to circulate synthetic resin powder and coat the metal material 5.

This apparatus is for coating metal materials 5 by flowing synthetic resin powder in parallel with the metal materials 5 in a coating header 17 provided outside the powder fluidization tank 4 for painting, so that the coating is performed as shown in FIG. 7. Since it is not caused by an upward flow of powder, there is no blind spot, and the drawbacks of the device shown in FIG. 6 can be covered.

However, in the case of this device, the cross-sectional shape of the wire body that is the metal material 5 is not circular, but is a twisted wire, or a steel wire with a recess.
In steel rods (for example, irregularly shaped PC steel rods), the powder flows almost parallel to the metal material 5, so the powder collides less frequently in the recesses, resulting in insufficient adhesion and pinholes. Cheap. For this reason, compared to the fluidized immersion method, the wire traveling speed must be set slower, and the equipment is complicated and the equipment cost is high.

(Problems to be Solved by the Invention) According to the above-mentioned conventional apparatus, if the linear metal material is a stranded wire or an irregularly shaped PC steel bar, the coating powder will be deposited in the concave part all around the circumference. The disadvantage is that the coating is not uniform and pinholes are likely to occur. In addition, according to equipment that implements the fluidized bed circulation method, unless the advancing speed of linear metal materials is slowed down, the coating layer of powder will not be uniform, resulting in failure rates and increased equipment costs. Means for Solving the Problems) The present invention takes the following measures to solve the problems of the conventional art.The present invention has a structure in which a painting room 1 is separated from an air chamber 2 by a porous body 3. An inlet 6 that allows a metal material 5 such as a wire or rod shape to continuously pass through the powder fluidization tank 4 for coating.
A continuous powder coating apparatus for metal materials, characterized in that a shielding plate 10 having a cutout part 8 and a shielding part 9 is provided at a position separated from the metal material 5 in the fluidizing tank 4. In this device, there is an air nozzle 11 (for example, a ring-shaped air nozzle 11) to prevent the powder from flowing out of the tank into the continuous flow rate lower of the powder fluidization tank 4 for coating.
is provided to prevent the powder from flowing out from the outlet lower part of the fluidizing tank 4 to save consumption of the powder and at the same time prevent deterioration of the working environment due to the powder.

(Function) As shown in FIG. 1, the present invention allows the synthetic resin powder a and the air in the air chamber 2 supplied by the blower b to pass through the porous body 3 to contain the powder a. Air and powder a are mixed in the fluidized fluidized tank 4 to form a fluidized bed, and a shielding plate 10 is installed at a certain distance from the lower surface of the linear or rod-shaped metal material 5 to partially block the upward flow of the fluidized bed. 9 and the notch 8 through which the upward flow passes, the upward flow of the powder a in the fluidized bed alternates in strength and weakness, which causes problems on the lower surface of the metal material 5, which is a problem in the conventional fluidized dipping method. It is possible to prevent pinholes from occurring due to insufficient welding. In order to prevent the powder a from flowing out from the fluidization tank 4, a mechanical seal 12 is provided on the entrance side of the metal material 50 to the fluidization tank 4.
The outlet side was a slit ring air nozzle 11.

The shape of the shielding plate 10 is, as shown in FIGS. 2 and 3, in the shape of a semicircular gutter or a flat plate, and is constructed by alternately forming notches 8 and shielding parts 9. An important factor of this shielding plate 10 is the dimension relationship, as shown in FIG.
It has been confirmed that by satisfying the following correlation between the diameter d3 and the diameter d3 of the linear metal body 5→C, it is possible to ensure stable formation of a film with good workability.

2 d3. ffdt f - d2 In such a dimensional relationship, the optimal ratio of the notch 8 of the shielding plate 10 to the shielding part 9 is 50-80:50-20.

The principle of the present invention will be explained with reference to FIG.

A fluidized layer of powder a formed on a shielding plate 10 having a notch 8 and a shielding part 9 provided below a linear metal material 5, which is an object to be coated, passes through the notch 8 of the shielding plate 10. It consists of a rising fluidized bed 13 and a sedimentary layer 14 formed by a settling flow above the shielding part 9, which together form a circulating flow. Therefore, the metal material 5 is connected to the fluidized layer 13 and the deposited layer 1.
4 alternately, the deposited layer 14 compensates for the insufficient amount of powder a deposited on the lower surface of the metal material 5 caused by the fluidized bed 13 having an upward flow, and the deposited layer 14 compensates for the insufficient amount of powder a deposited on the lower surface of the metal material 5. Apply the paint powder.

As described above, the ratio of the lengths of the notch 8 and the shielding part 9 provided in the shielding plate 10 is optimally in the range of 50 to 80:50 to 20. For example, if the ratio of the cutout portion 8 is made extremely large, defects will occur on the lower surface of the metal material that occurs in the conventional fluidized dipping method, and if the shielding portion 9 is made extremely large for correspondence, the fluidized bed 1
The reflux of No. 3 is weak and fluidity is lost, leading to insufficient replenishment of synthetic resin powder No. 9 and a blocking phenomenon in which the deposited layer 14 is heated and the synthetic resin no. 9 adheres, making continuous processing impossible. Therefore, by setting the ratio within the above range, the synthetic resin powder a of the deposited layer 14 can be appropriately replaced with the fluidized bed 13, and the conventional problems can be solved.

(Example) In the present invention, an epoxy resin coating was applied to a metal material 5 made of a steel wire of 11 oφ using the configuration described in the section for solving problems and the apparatus shown in FIG.

Tank length of painting room 1: 1200% The shielding plate 10 has a semicircular gutter shape with a grid cutout (cutout: shielding)
2:1) Even if the linear velocity of the metal material 5 is 10 to 30 mz, the coating thickness is 100 to 300 μm.
It was possible to form a good paint film with no pinholes.

(Effects of the Invention) The present invention uses a simple and trouble-free apparatus, which makes it possible to uniformly and continuously coat coating powder in the form of gold nuggets, and enables efficient coating work. effective.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing one example of implementing the present invention, Figures 2 and 3 are
Figure 4 is a perspective view of the shielding plate, Figure 4 is a diagram explaining the dimensional relationship between the coating chamber and the shielding plate, Figure 5 is a diagram explaining the operation of the present invention, Figure 6 is a sectional view of the conventional device, and Figure 7 is painting. FIG. 8 is an explanatory diagram of a conventional device. 1 is a painting room, 2 is an air chamber, 3 is a porous body, 4 is a fluidized tank,
5 is a metal material, 6 is an inlet, 7 is an outlet, 8 is a notch, 9 is a shielding portion, 10 is a shielding plate, 1 is an air nozzle, 12 is a mechanical seal, 13 is a fluidized bed, 14 is a deposited layer, 15 is a blind spot, 16 and 18 are flow paths, 17 is a ladder to coating, 19 is a tank, a is a powder, and b is a blower 0

Claims (2)

[Claims] (1) An inlet and an outlet for allowing metal materials to pass continuously are provided in a fluidized powder tank for painting, which is separated by a porous material from the air chamber provided in the painting room, and located at a location in the fluidized tank separated from the metal materials. 1. A continuous powder coating device for metal materials, characterized in that a shielding plate having a cutout portion and a shielding portion is provided. (2) The metal according to claim 1, wherein an air nozzle for preventing the powder from flowing out of the tank is provided at the outlet for continuous passage of the metal material of the powder fluidization tank for coating in the painting room. Continuous powder coating equipment for materials.