JPS5939358A - Apparatus for electrostatically coating wire body - Google Patents

Abstract

PURPOSE:To perform uniform coating, by a method wherein a chamber for confining fine particles of a coating agent sprayed from an electrostatic sprayer is formed of a metal body to control a coating amount to a wire body. CONSTITUTION:A wire body 4 advances toward a passing port 1c through a chamber 2 along a running direction A from a passing port 3a to be coated with a coating agent by an electrostatic sprayer 7 during this time. Because the chamber 1 comprises a conductive metal such as stainless steel or brass and the chamber 1 and the fine particles of the coating agent therein are brought to a potential different in polarity when a positive polarity voltage source 21 and the chamber 1 are connected by a change-over switch 23, the fine particles are attracted by the inner wall of the chamber 1. Therefore, the amount of the coating agent to be applied to the wire body 4 is reduced and the film thickness becomes thin. On the other hand, in order to improve coating efficiency on the wire body 4, a negative polarity voltage source 22 is connected to the chamber 1 by the change-over switch 23 to mutually bring both of them to potentials same in polarity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic coating device for a linear body that can uniformly apply a coating agent over the entire circumference of a thin linear body.

Conventionally, in order to apply atomized coating agent fine particles to a thin linear body with a wire diameter of about 0.05 to 50 mm, an electrostatic or air atomizer was used in a large coating booth. are arranged perpendicularly to the running direction of the linear body, and the coating operation is performed while the linear body is traveling at a predetermined speed.

“However, with such conventional technology, firstly, the wire diameter of the linear body is much smaller than the coating nozzle width of the sprayer, so the coating efficiency is very poor. Second, if the coating agent particles do not fly at right angles toward the linear object, the coating agent particles will scatter toward the inner wall of the coating booth, causing damage inside the coating booth. The drawback is that it is difficult to recover wasteful coating agents, as well as stains.Thirdly, in the prior art, the coating film width is uniform around the entire circumference of the linear body. In order to obtain this, multiple sprayers must be installed in the coating booth, which has the disadvantage of making the equipment complex and large.

The purpose of the present invention is to improve the drawbacks of the prior art coating apparatus for linear bodies described above, and the present invention confines coating agent fine particles sprayed by an electrostatic sprayer in a chamber made of a metal body. By running the linear body in the chamber, the coating agent can be applied uniformly to the entire circumference of the linear body. t
- Provided.

In order to achieve the above object, the present invention has a configuration that includes a chamber formed by a cylindrical metal body to confine coating agent fine particles therein, and a chamber in which charged coating agent fine particles are sprayed. A station t1. is provided facing into the chamber. a sprayer, and a voltage source connected to the chamber made of the metal body for applying a normal pressure of the same polarity or a different polarity to the coating agent fine particles to the chamber,
The coating agent fine particles are applied to the linear body while one or more linear bodies are running in the chamber with a desired full voltage applied to the chamber.

In this way, when the chamber is formed of a metal body and a voltage of the same polarity as the charged coating agent particles is applied to the chamber, a repulsive force is applied from the inner wall of the chamber toward the linear body. Therefore, the effect of confining the particles of the coating agent in the chamber can be further enhanced. Therefore, due to the electrostatic attraction force due to the electric field formed between the electrostatic sprayer and the linear body in the chamber, the particles of coating agent confined within the range of the electrostatic attraction force are removed by the electrostatic force. The coating can be applied to the object without waste and the coating efficiency can be increased.

Conversely, by applying a voltage of a different polarity to the coating agent fine particles to the chamber, suction force can be applied toward the inner wall of the chamber, so that the coating agent fine particles it, which are applied to the linear body,
t-can be decreased. Therefore, in this case, it is possible to reduce the efficiency of coating onto the linear body, and the film thickness can be controlled by adjusting the applied voltage.

Furthermore, since the chamber can be made small in size, it is possible to easily collect the coating agent adhering to the chamber.

Here, in the present invention, as the linear body, for example, a copper wire,
Metal wires like iron # or these twisted] wires, threads, resins like threads! A glass wire such as a wire or an optical fiber, and its cross-sectional shape is defined as a concept including circular, rectangular, plate-like, etc. In addition, as coating agents, solvent paints such as amino alkyd, acrylic, polyurethane paints, and non-aqueous disno paints can be used. J wn paint, high sled,
These include not only hard-based paints, water-based paints, powder paints, etc., but also ultraviolet-curable paints, electron-beam-curable paints, oils for coating linear bodies, and the like. Furthermore, various types of electrostatic atomizers can be used as long as they can charge the particles of the coating agent by applying a high voltage.For example, a rotary atomizer that uses centrifugal force Head type electrostatic sprayers, airless electrostatic sprayers that use liquid pressure, air atomization type electrostatic sprayers that use atomizing air, ultrasonic electrostatic sprayers that use ultrasonic atomization, etc. Defined as including.

The present invention will be described below along with embodiments shown in the drawings.

In the figure, reference numeral 1 denotes a chamber made of a cylindrical body arranged such that the pivot leg is vertical, and the chamber is made of a conductive metal such as stainless steel, brass copper, aluminum, iron, etc. A chamber chamber 2 is formed within the chamber 1 . The upper side 1m of the chamber 1 is covered with a lid 3 having a linear body passage opening 3a, and the lower side 111
11b also serves as a coating agent outflow prevention wall *M-shaped body passage port IC
is formed, and is bent horizontally to form a flange portion 1.
d is formed.

Reference numeral 4 indicates a linear body (only one is shown in the drawing) to which a coating agent is applied in the chamber 2, and the linear body 4 is used, for example, in a copper wire manufacturing device, an optical fiber manufacturing device, etc. It is manufactured by the body manufacturing apparatus 5.

Reference numeral 6 denotes a guide roller placed at ground potential, and the linear body 4 manufactured as described above becomes at ground potential while being guided by the guide roller 26, and is further inserted into the linear body passing port 3a+1c, as indicated by the arrow in the figure. The coating agent is applied within the chamber 2 while moving in the traveling direction shown in FIG.

Reference numeral 7 denotes an electrostatic sprayer fixedly installed 1 m above the chamber 1, and the electrostatic sprayer 7 connects to a coating agent tank 12 via an air atomizer 11 and to an air source via an air hose 13. 14, respectively. And electrostatic sprayer 7
Furthermore, the dome 7a is provided obliquely facing into the chamber 2 in the running direction A, that is, toward the lower side 1b, and the needle-shaped electrode 7b at the tip of the dome 78 is connected to a high voltage source 9. By applying a high voltage, an ionized sphere is formed around the needle-like polarizer 7b, and an electrostatic field is also formed between it and the linear body 4, which is at ground potential, by the guide row 26. Also,
The coating agent ejected from the do portion 7a is atomized by the atomizing air from the air source 14, and the coating agent fine particles are charged while passing through the ionization zone, and static electricity between them and the linear body 4 increases. The charged particles of the coating agent fly along with the electric lines of force EK caused by the electric field, and are coated on the linear body 4.

Reference numeral 15 indicates an exhaust pipe connected to the tank portion 1d on the lower side 1b of the chamber 1, and the exhaust pipe 15 is made of a material different from that of the chamber 1, for example, a resin material. One side of the exhaust pipe 15 has a flange part 15m attached to the 7 tank part 1d [L and 1111 are the exhaust port 1
5b and tteo F), there is a 7 rung part 1 in the exhaust pipe 15.
In order to recover the coating agent by depositing the coating agent from 5 m toward the exhaust port 15b, there is a grounded coating agent recovery friction plate 16, a coating agent separation filter 17, and a fan 1.
8 are provided respectively. On the other hand, the exhaust pipe 15 is provided with a coating agent recovery pipe 19 located near the jam plate 16.
The coating agent collected by the coating agent fine particles adhering to the scraping plate 16 is transferred to the tank 20 via the coating agent collection pipe 19.
collected and reused.

On the other hand, 21 indicates a positive voltage source 22 and a negative voltage source, and each of the voltage sources 21 and 22 is connected to the chamber l via a changeover switch 23. Here, each of the voltage sources 2 and 22 is of a modified voltage type so that the voltage applied to the chamber 1 can be set to a desired value. And high voltage source 9
When the voltage source generates a negative high voltage, by switching the changeover switch 23 to the positive voltage source 21 side, the coating efficiency can be reduced and the film thickness can be controlled.
Conversely, by switching the changeover switch 23 to the negative electrode voltage source 22 side, it is possible to confine the coating agent fine particles within the chamber 1.Furthermore, 24 is a drying chamber provided at the next stage of the chamber 1. Channo for drying? This is for baking and drying the linear body 4 coated with a coating agent in the 24Fi chamber 1, and a drying source 25 is provided inside the chamber 1, and a fan 26 is provided in the exhaust duct 24m. . Here, as the drying source 25, a heat source such as a heater is used when the coating agent is a solvent paint, an ultraviolet generation source is used when the coating material is an ultraviolet curable paint, and an ultraviolet source is used when the coating material is an electron beam curable paint. An electron beam source is used. The linear body 4 from the linear body passing port IC of the chamber 1 is dried while passing through the drying chamber 24, and is wound up by a winding device 27 provided next to the chamber 240. It is configured.

Although the present invention is configured as described above, the linear body manufacturing apparatus 5
The linear body 4 manufactured by
The wire passes through the chamber 2 from the linear object passage port 3a while being guided by the linear object passage port 3a, exits from the linear object passage port IC, passes through the drying chamber 24, and is wound up by the winding device 27. During this time, when the powder 4 passes through the chamber 2 along the traveling direction A, the coating agent is applied by the electrostatic sprayer 7 .

That is, by applying a high voltage to the needle-like electrode 7b of the electrostatic sprayer 7, an ionization sphere is formed around the needle-like electrode 7b, and lines of electric force E are created between the needle-like electrode 7b and the linear body 4. Since the particles are formed, the particles of the coating agent sprayed from the do part 7a are charged while passing through the ionized sphere t, and an electric force 111 is generated.
i! After flying in E, it is applied to the linear body 4. Then, the linear body 4 coated with the coating agent is placed in a drying chamber 24.
The coating agent is dried and baked, and the wire-shaped body that has been coated in this way is wound up by the winding device 27.

On the other hand, the coating agent fine particles that have not been applied to the linear body 4 are sucked toward the exhaust port 15b side of the exhaust pipe 15 by the fan 18. During this time, the particles of the coating agent adhere to the grounded friction plate 16, grow and fall, and flow from the coating agent collection pipe 19 to the tank 20.
The remaining coating agent fine particles are removed by the filter 17, and the cleaned exhaust gas is discharged outdoors through the exhaust port 15b. By applying a voltage of a different polarity to the coating agent fine particles to the interference plate 16, the recovery efficiency of the coating agent can be further increased.

On the other hand, if a negative high voltage of, for example, ±5 to 90 kV is applied to the needle-shaped electrode 7a of the electrostatic sprayer 7 by the high voltage generator 9, the particles of coating agent in the chamber 2 Therefore, in order to control the coating film by reducing the coating efficiency of the coating material applied to the linear body 4, the changeover switch 23 is used to switch the positive electrode voltage source. 21 to be connected to chamber l. As a result, a positive potential is applied to the chamber 1, the coating agent fine particles in the chamber 2 are adsorbed to the inner wall of the chamber 1, and the coating agent grown in a liquid state flows down along the inner wall. Therefore, the number of coating agent fine particles to be applied to the linear body 4 is reduced, and the coating film can be made thinner. At this time, the film thickness can be easily controlled by fully adjusting the voltage to be applied to the chamber I.

Contrary to the above, in order to increase the efficiency of coating onto the linear body 4, the negative electrode voltage source 22 may be connected to the chamber l using the changeover switch 23. As a result, the inner wall of the chamber 1 and the coating agent fine particles repel each other, thereby further enhancing the confinement effect within the chamber 2 and improving the coating efficiency on the linear body 4. Further, staining of the inner wall of the chamber 1 by the coating agent can also be prevented.

Next, regarding the shape of the chamber 1, the inside of the chamber 2 is set within the range of effective electrostatic attraction, and as many particles of the charged coating agent confined within the chamber 2 as possible are transferred to the linear body 4. It is desirable to apply it. Therefore, in the present invention, the voltage applied to the needle electrode 7b is set to ±5 to 9.
When setting it to 0kV, the inner diameter of chamber 1 is within 800 degrees,
In addition, the longitudinal force direction length fil'' of the linear body 4 along the running direction A
By setting the distance to 300 m or more, the inside of the chamber 2 will be affected by electric lines of force E due to an electrostatic field. As a result, all of the coating agent fine particles confined within the chamber 2 can fly and be applied to the linear body 4 along the lines of electric force E. In this way, in the present invention, the chamber 1
Since the shape can be within the range of effective electrostatic attraction, waste of the coating agent can be reliably prevented and coating efficiency can be increased.

Furthermore, by arranging the do part 7a of the electrostatic sprayer 7 obliquely so as to face the downstream side with respect to the running direction A of the linear body 4, it is possible to overflow in the running direction A as shown in p1. Electric force can be generated, and the coating material can be applied uniformly throughout.

Although the chamber 1 is described as a cylindrical body in the above-described embodiment, it may be a square cylindrical body, or the chamber 1 and the exhaust pipe 15 may be integrally formed. Also,
Although the chamber 1 has been described as being provided vertically so that the linear body 4 runs from above to below, the chamber 1 may be provided so that the axial direction thereof is horizontal. Further, although it has been described that the linear body 4 is brought to earth potential by the guide roller 6, it may be replaced with a brush or the like, and if the linear body manufacturing apparatus 5 itself can be brought to earth potential, the guide roller 6 may be brought to earth potential. The roller 6 can be made unnecessary. Furthermore, it goes without saying that when it is not necessary to apply the full chamber voltage, the changeover switch 23 may be placed in the neutral position.

The electrostatic coating device for linear objects according to the present invention is as described in detail above, and includes a single spray of charged coating agent fine particles in a chamber formed on a metal body. Since voltages of the same polarity or different polarities can be applied to the chambers, by applying voltages of the same polarity to the chambers, it is possible to enhance the effect of confining the coating agent fine particles within the chambers. Therefore, coating agent fine particles within the range of the electrostatic attraction force are not wasted and the coating efficiency can be greatly increased, and since the coating agent is prevented from adhering to the inner wall of the chamber, the inner wall is also prevented from being contaminated. sell. On the other hand, by applying a voltage of the same polarity to the chamber, the coating agent fine particles in the chamber are adsorbed to the inner wall of the chamber, making it possible to thin the coating film applied to the linear body, thereby reducing the coating efficiency. I can do it. Therefore, the film thickness can be easily controlled by adjusting the potential of the different polarity voltage.

Furthermore, so that the entire chamber is affected by the electrostatic field,
By selecting the shape of the chamber, the particles of the coating agent in the chamber can be well applied to the linear body, and the recovery ratio of the coating agent can be significantly lowered compared to the conventional technology. It has excellent effects.

[Brief explanation of the drawing]

The figure shows an electrostatic coating device for linear objects according to the present invention.
Chamber, 2... Chamber chamber, 4... Linear body, 7.
... Electrostatic sprayer, 9 ... High voltage source, 12 ... Coating agent tank, 14 ... Air source, 15 ... Exhaust pipe, 2
1... Positive polarity voltage source, 22... Different polarity voltage source, 23...
・Changing switch, CH, 24... Channo Z for drying.

Claims (4)

[Claims] (1) A chamber formed by a cylindrical metal body to confine coating agent fine particles inside, and a static TfL sprayer provided facing into the chamber so as to spray the charged coating agent fine particles inside the chamber. and a voltage source connected to the chamber made of the metal body to apply a voltage of the same polarity or different polarity on the coating agent fine particles, and a desired voltage is applied to the chamber. An n-electronic coating device for a linear body, wherein coating agent fine particles are applied to the linear body while the linear body is traveling in the chamber. (2) A voltage having the same polarity as that of the coating agent particles is applied to the chamber to enhance the effect of confining the coating agent particles within the chamber.
h in ) is D for shaped objects [coating device]. (3) The scope of the patent claim (
1) The electrostatic coating device for linear bodies as described in item 1). (4) The electrostatic coating device for a linear body according to claim (1), wherein the entire linear body is held at a ground potential.