JPH019647Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a coating device, in particular, a solid strippable paint containing a wax material is heated and melted and sprayed from a paint spraying device, and a grid electrode to which a high voltage is applied is used to apply the solid strippable paint to the coating material. This invention relates to a coating device that electrostatically coats objects.

This type of coating equipment is used to temporarily apply a coating film to the surface of objects to be coated, such as steel plates, aluminum plates, copper plates, etc., to prevent rust and stains. It is called a strippable paint (or strip paint) because it must be able to be easily peeled off from the surface of the object to be coated after it has served its purpose.

The strippable paint used is, for example, a vinyl chloride-vinyl acetate copolymer mixed with a large amount of a softening agent containing a wax material such as paraffin. Among these, plastisol-type and organosol-type strippable paints (commonly known as press oils) not only have a rust-preventing effect but also improve sheet metal workability. Painted on the surface etc.

By the way, this kind of strippable paint is
Since it contains wax material, it is solid at room temperature. Therefore, in order to apply this strippable paint to the surface of the object to be painted, such as the metal plate, it must be supplied to a paint spraying device in a heated and molten state, and must be sprayed in a relatively high temperature atmosphere. Must be.

Therefore, a coating apparatus for this purpose will be explained based on FIG. 1. A carrying-in port 2 and a carrying-out port 3 through which the object to be coated 1 such as a strip-shaped metal plate transported at a required speed is carried in and out are formed above and below, and a peripheral wall In a chamber 5 in which a heat insulating material 4 such as glass wool is disposed, paint spraying devices 6R and 6L are disposed facing each other with the object 1 to be coated in between. Grid electrodes 7 facing each other
R and 7L are arranged.

The paint spraying devices 6R and 6L are rotated by a drive motor (not shown) while a part of the strippable paint is immersed in the heated and molten strippable paint fed into a paint reservoir (not shown). a rotating pick-up roller 8 and a rotating pick-up roller 8
The sprayer 9 peels off paint adhering to the surface of the paint, atomizes the paint using pressurized air, and sprays the atomized paint. An electric heater (not shown) is installed to heat the air to about 100 to 120°C, and the pressurized air is heated to a high temperature of about 200 to 300°C to prevent the sprayed paint particles from solidifying. are doing.

Furthermore, the paint tank 11 that stores the strippable paint 10 is heated to approximately 100 to 120°C by an electric heater 12.
The paint is heated to melt the paint, and the paint in the paint tank 11 is transferred to the paint spraying devices 6R and 6L.
A ribbon heater 15 is also wound around the outer periphery of the paint supply pipe 13 and pressure pump 14 to prevent the paint from solidifying.

The grid electrodes 7R, 7L are, for example, DC-10~
It is composed of a linear body to which a high voltage of about 100 KV is applied, and is stretched over an aluminum electrode mounting plate 17 fixedly installed inside the chamber 5 via an insulating support 16.

Thus, the strippable paint 10 in the paint tank 11 is heated and melted by the electric heater 12.
is fed into the paint reservoirs of the paint spraying devices 6R and 6L by the pressure pump 14 through the paint supply pipe 13, and is deposited on the rotating pick-up roller 8, which is peeled off by the sprayer 9 and heated to 200 to 300°C.
The heated pressurized air is sucked in and sprayed upward from the spray nozzle 9a.

Here, the grid electrodes 7R, 7L disposed above the paint spraying devices 6R, 6L have DC-10 to
Since a high voltage of 100 KV is applied, an electrostatic field is formed between the grid electrodes 7R and 7L as cathodes and the grounded object 1 as an anode. Therefore, as described above, the paint spraying device 6R,
The paint particles sprayed upward from the 6L sprayer 9 and thrown up are charged by the grid electrodes 7R and 7L, and are electrostatically applied to the surface of the object 1 to be coated with opposite polarities.

However, with the conventional coating device, there was a problem in that some of the paint particles sprayed from the sprayer 9 adhered to the surfaces of the grid electrodes 7R and 7L, and were cooled to a temperature below the melting point and solidified. .

That is, some of the paint particles sprayed from the atomizer 9 together with pressurized air heated to 200 to 300°C adhere to the grid electrodes 7R, 7L, and after being cooled, are removed from the grid electrodes 7R, 7L in the form of strings or lumps. The object 1 collapses due to electrostatic attraction.
The problem was that it was adsorbed to the surface of the paint, causing uneven coating.

In particular, when the object 1 to be coated is a metal plate before being subjected to can press processing, and when the strippable paint 10 such as press oil is applied thereto, if the above-mentioned coating film unevenness occurs, the press During processing, the coefficient of friction between the metal plate and the press that presses it differs locally, resulting in a serious drawback in that the metal plate may be deformed due to abnormal slippage or the plate may break.

Therefore, the present invention aims to provide a coating device that prevents the paint from adhering to the grid electrode and solidifying when using a strippable paint containing a wax material, thereby causing no uneven coating. purpose.

In order to achieve this objective, the present invention provides a paint spraying device that heats and melts a solid strippable paint containing a wax material and sprays it, and a paint spraying device that charges the paint particles sprayed from the paint spraying device to coat the object to be painted. A coating apparatus having a grid electrode for electrostatically applying the coating to the surface of the surface of the surface of the surface of the surface of the surface, the grid electrode being formed of a heating wire, and having an energizing means for heating the heating wire to a required temperature.

Hereinafter, embodiments of the present invention will be specifically described based on the drawings.

Note that the same reference numerals are given to parts that are common to the above-mentioned configuration, and detailed explanation thereof will be omitted.

FIG. 1 is a side view showing an example of the configuration of the coating apparatus according to the present invention. In the present invention, the grid electrodes 7R, 7L are formed of heating wires such as nichrome wires, and the heating wires are used as required. It has an energizing means for heating to a temperature.

That is, FIG. 2 shows the grid electrode 7 according to the present invention.
It is a front view showing an example of R, 7L, and is an electrode mounting plate 17 made by bending both left and right ends of an aluminum plate.
Tubular insulators 18 are inserted through the side plate portions 17a, 17a at predetermined intervals, and one heating wire N is sequentially inserted through each insulator 18 and stretched in a meandering manner. Further, both ends of the heating wire N are connected to a conducting wire 23 with a generator 22 interposed therebetween via connectors 20 and 21, thereby forming a closed circuit.

An air motor 24 for rotationally driving the generator 22 is directly connected to the generator 22, and the generator 22 and the air motor 24 are placed on an insulating support base 25 and maintained in an electrically insulated state. Note that 26 is a DC high voltage generator that applies a high voltage to the heating wire N.

FIG. 3 is a perspective view of the grid electrodes 7R, 7L as seen from the back side, in which a heating coil 27 is attached to the back of the electrode mounting plate 17.

As shown in FIGS. 1 and 3, this heating coil 27 is used for circulation in which insulating oil 29 in an oil tank 28 disposed outside the chamber 5 is heated by a heater 30 and pumped under pressure by a pump 31. Outward route 32 and
It is inserted into an insulating oil circulation pipe system consisting of a circulation return path 33 for recovering the pressure-fed insulating oil 29 into the oil tank 28.

In addition, in FIG. 1, 34 and 35 are an air supply pipe and an exhaust pipe of the air motor 24, respectively.

The above is an example of the configuration of the coating device according to the present invention, and the operation thereof will be explained next.

First, the insulating oil 29 stored in the oil tank 28 is heated to a required temperature by the heater 30.
This is fed by a pump 31 through a circulation path 32 to a heating tube 27 attached to the back of the grid electrodes 7R, 7L, and the heating tube 27 and the electrode mounting plate 17 in contact with the heating tube 27 are heated sufficiently to melt the strippable paint. Heat to a temperature (approximately 60-100℃).

At the same time, high pressure air is supplied to the air motor 24 from the air supply pipe 34, and the air motor 2
4 is rotated at high speed, thereby the air motor 2
The generator 22 directly connected to the generator 4 is rotated to generate electricity. Then, the electric power is supplied to the heating wires N constituting the grid electrodes 7R and 7L through the conductor 23, and the heating wires N are heated to a temperature of about 60 to 100, which is sufficient to melt the strippable paint, in the same manner as described above.
At the same time as heating to about .degree. C., a high voltage of about DC-10 to 100 KV is applied to the heating wire N from the DC high voltage generator 26.

Next, the strippable paint 10 stored in the paint tank 11 is heated and melted by the electric heater 12, and is fed into the paint reservoirs of the paint spraying devices 6R and 6L through the paint supply pipe 13 by the pressure pump 14, Here, heat to about 100-120℃ or up to 250℃. A rotating pick-up roller 8 transports the molten paint fed into the paint reservoir.
At the same time, it is peeled off using a sprayer 9, and approximately
The particles are atomized and sprayed upward from the spray nozzle 9a of the sprayer 9 using pressurized air heated to 200 to 300°C.

At the same time, the grounded plate-shaped object 1 to be coated is transferred at a required speed.

Here, the heating wires N of the grid electrodes 7R, 7L disposed above the paint spraying devices 6R, 6L,
Since a high voltage of DC-10 to 100KV is applied, an electrostatic field is formed between the two electrodes with the heating wire N as the cathode and the grounded object 1 as the anode, and therefore the field is directed upward from the sprayer 9. The paint particles that are sprayed and thrown up are charged by the heating wire N and electrostatically applied to the surface of the object 1 to be coated, which is the opposite polarity.

At this time, some of the paint particles atomized and sprayed as described above adhere to the heating wire N and the electrode mounting plate 17 that mounts and supports the heating wire N.
Since both the electrode mounting plate 17 and the electrode mounting plate 17 are heated to a temperature sufficient to heat and melt the adhered paint,
It does not cool and solidify on its surface.

Therefore, as in the conventional case, the paint adhering to the grid electrode cools and solidifies, and it collapses from the grid electrode in the form of threads or lumps, leaving the object to be coated 1.
The coating is electrostatically applied to the surface of the object 1 to be coated, and there is no possibility that uneven coating will occur on the surface of the object 1 to be coated.

In addition, as described above, the heating wire N and the electrode mounting plate 17
By heating and melting the paint that adheres to the
When a certain amount of adhered paint reaches a certain level, it drips in the form of droplets, which can be easily collected and reused, which has the advantage of not wasting any paint.

In addition, in the above-mentioned embodiment, a case has been described in which the generator 22 is rotationally driven by the air motor 24 as the energizing means for heating the heating wire N, but the present invention is not limited to this. Although not shown, any other current supply means may be adopted, for example, an electric motor may be disposed outside the chamber 5, and the rotation of the electric motor may be transmitted to the generator 22 via an insulating shaft for rotation. It may also be dynamically driven.

Further, the electrode mounting plate 17 on which the heating wires N forming the grid electrodes 7R and 7L are stretched is not limited to being made of an aluminum plate as described above, but may be made of a comparatively heat-resistant synthetic resin material such as Delrin, for example. It may also be a case of molding. Moreover, if it is formed of an insulating material such as Delrin, the heating wire N can be directly stretched on the electrode mounting plate 17 without using the insulator 18 or the like.

Further, as the paint spraying devices 6R and 6L, in addition to the device using the pick-up roller 8 as described above, any paint spraying device having a conventionally known air atomization mechanism can be applied.

As described above, according to the present invention, since the grid electrode is formed of a heating wire and has an energizing means for heating the heating wire to a required temperature, a solid strippable paint containing a wax material is used. When the strippable paint is heated and melted and sprayed, even if the strippable paint adheres to the grid electrode, it will not solidify. Therefore, it has an excellent effect in that the paint adhering to the grid electrode does not form into lumps, collapse and separate from the grid electrode, and does not adhere to the surface of the object to be coated and cause uneven coating.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of the configuration of a coating device according to the present invention, FIG. 2 is a front view showing an example of the grid electrode, and FIG. 3 is a perspective view of the coating device as seen from the back side. Explanation of symbols, 1...Object to be painted, 5...Chamber, 6R, 6L...Paint spraying device, 7R, 7L...
... Grid electrode, N ... Heating wire, 22 ... Generator, 24 ... Air motor, 26 ... DC high voltage generator.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A paint spraying device that heats and melts a solid strippable paint containing a wax material and sprays it, and paint particles sprayed from the paint spraying device that are charged and applied to an object to be painted. A coating apparatus having a grid electrode for electrostatically applying the coating to the surface of the grid, wherein the grid electrode is formed of a heating wire, and has an energizing means for heating the heating wire to a required temperature. . (2) The coating apparatus according to claim 1, wherein the energizing means is constituted by a closed circuit interposed with a generator driven by an air motor.