KR101503337B1 - Apparatus of electrostatic powder coating of conducting powder using binder and method of coating by the apparatus - Google Patents

Abstract

The present invention provides an electrostatic powder coating apparatus of conductive powder using a binder and a coating method thereof for securing sufficient coherence of the conductive powder attached to a porous metal and forming a conductive coating layer by being laminated at a desired thickness uniformly. The present invention includes: a support on which the porous metal is fixed and which is charged in a first type charge; a charging unit which charges the conductive powder coated on the porous metal in a second type charge having a polarity opposite to the first type charge; a power supply source which supplies the second type charge to the charging unit; a powder storage which stores the conductive powder for transferring to the charging unit; and a binder solution supplying unit which supplies binder solution to the conductive coating layer forming conductive powder coated on the porous metal. The present invention can increase coherence by using the binder for the charged conductive powder to be coated on the porous metal by using static electricity force.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic powder coating apparatus for a conductive powder using a binder and a coating method using the binder,

The present invention relates to an electrostatic powder coating apparatus and a coating method thereof, and more particularly, to an apparatus for coating a conductive powder itself by a electrostatic powder coating method on a porous substrate of a metal matrix by applying a binder and a coating method thereof will be.

The ceramic porous body, which is mainly used as a porous carrier, has a low thermal shock resistance in spite of the high temperature stability of the ceramic material, and the manufacturing process thereof is complicated. In addition, high-temperature sintering is required, and the cost is high. In order to solve such a problem, recently, a porous base of a metal base (hereinafter referred to as a porous metal body) has been substituted for a ceramic porous body, and it is expected that the application field will be expanded as a new area utilizing the metal characteristics. The metal porous body has a three-dimensional network structure and can be used as a core material for the environment and the energy industry such as electrodes for solar cells and fuel cells, filters for environmental pollution and purification, catalyst carriers, and highly efficient heat exchange media. It is expected to increase rapidly as a core component of environmental and energy technologies such as green car, super clean ship, greenhouse gas supporting industry, large-scale hydrogen generation, distributed power generation, and production of high efficiency alternative fuel .

On the other hand, when a metal porous body is coated with a conductive powder such as a metal or a semiconductor to form a conductive coating layer, a metal porous body that exhibits properties of the conductive powder, such as catalyst characteristics, can be realized. The conductive coating layer may be formed using a wet coating method such as wash coating, electrostatic spraying, slurry coating and the like. Such a wet coating method has various problems such as difficulty in coating a large area, slow coating speed, and environmental pollution, and thus a method of coating conductive powder using electrostatic powder has been proposed.

The method for coating the conductive powder using the electrostatic powder is such that the powder itself is charged to the anode, and the metal porous body of the cathode is coated by the electrostatic force. However, as the conductive coating layer is piled up, the phenomenon that the conductive powder falls off is increased. In this case, it is difficult to form a relatively thick conductive coating layer on the porous metal body. That is, the bonding force of the conductive coating layer is weakened, so that the conductive powder forming the conductive coating layer is not stacked well and the coating layer is not uniform. The voltage applied to the electrostatic powder can be increased in order to allow the electroconductive powder to be laminated well, but the loss of energy is large and the work safety is poor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic powder coating apparatus for a conductive powder using a binder that forms a conductive coating layer uniformly laminated to a desired thickness by ensuring a sufficient bonding force of the conductive powder adhered to the porous metal body and a coating method therefor There is.

In order to solve the problems of the present invention, there is provided an apparatus for electrostatic powder coating of conductive powder using a binder, comprising: a metal porous body to which a metal porous body is adhered; a supporting table that is charged with a first type of charge; and a conductive powder coated on the metal porous body, And a charge of a second type opposite in polarity to the charge. And a powder reservoir for storing the conductive powder to be supplied to the charge portion, and a powder reservoir for storing the conductive powder for supplying the charge to the charge portion. And a binder liquid supply unit for supplying the binder liquid to the conductive coating layer made of the conductive powder coated on the porous metal body. At this time, the charge of the second type may be a negative charge or a positive charge.

In the apparatus of the present invention, the support base can be rotated in at least one of up and down, right and left, forward and backward, or in a cylindrical shape. At this time, the voltage applied to the charge portion is preferably 10 KV to 10,000 KV. The average particle diameter of the conductive powder is determined by the surface state of the porous metal body, the average weight (W) of the conductive powder when the injection time (T) injected from the charge is constant, A spraying speed V for jetting, a distance D between the charging part and the porous metal body, and an injection flow rate F of the conductive powder. The average particle diameter of the conductive powder is preferably 100 nm to 1 mm.

In the preferred apparatus of the present invention, the conductive powder may be any single element selected from metals or semiconductors having conductivity, or alloys thereof (including solid solution). For example, the conductive powder may be at least one selected from the group consisting of carbon (C), silicon (Si), a conductive polymer, iron (Fe), chromium (Cr), nickel (Ni), cobalt (Co), platinum (Pt), palladium , Gold (Au), silver (Ag), barium (Ba), or an alloy thereof (including solid solution). In addition, the porous metal body may be a single metal consisting of a single element or an alloy thereof (including solid solution). For example, the porous metal body may be at least one selected from the group consisting of Fe, Ni, Al, Ti, Cu, noble metal (Ag, Au, Pt, Pd) Lt; / RTI >

In the binder solution of the present invention, the binder solution may be one in which the binder is dissolved or dispersed in a non-aqueous or aqueous solvent. The binder may be selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, paraffin wax, carabona wax, chitosan, cellulose derivative, starch derivative, saccharide derivative, polyethylene oxide, carrageenan, At least one selected from the group consisting of carrageenan, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone and polyhydroxy compound desirable.

In order to solve the problems of the present invention, a conductive powder coating method of a conductive powder using a binder is carried out by first introducing a conductive powder into a powder reservoir and fixing the porous metal body to a support supported by a first type of charge. Then, a second type of charge opposite in polarity to the first type of charge is supplied to the charge portion from the power source. And the conductive powder stored in the powder reservoir is sent to the lower part. And the conductive powder charged with the charge of the second form is injected into the porous metal body from the charge part. The binder liquid is supplied to the conductive coating layer coated with the conductive powder on the porous metal body.

The method of the present invention may further comprise the steps of supplying the second shape charge to the charge portion, sending the conductive powder to the charge portion, spraying the conductive powder to the porous metal body, May be repeatedly performed. At this time, the support can be moved at least one of up and down, left and right, back and forth, and rotation. The binder is selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, paraffin wax, carabona wax, chitosan, cellulose derivatives, starch derivatives, saccharide derivatives, polyethylene oxide, carrageenan, May be at least any one selected from the group consisting of rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound . Further, the method may further include the step of collecting the removed conductive powder not attached to the porous metal body with the powder collecting tank.

According to the electrostatic powder coating apparatus of the conductive powder using the binder of the present invention and the coating method therefor, by using the binder in the process of coating the conductive powder itself on the porous metal body by the electrostatic powder coating method, It is possible to secure a bonding force and to obtain a conductive coating layer which is uniformly laminated to a desired thickness.

1 is a schematic view for explaining an electrostatic powder coating apparatus of a conductive powder using a binder according to the present invention.
FIG. 2 is a flow chart showing a method of electrostatic powder coating of a conductive powder using a binder according to the present invention.
3 is a photograph of a Fe-Ni porous body according to Example 1 of the present invention.
FIG. 4A is a photograph of a Fe-Ni porous body produced by Embodiment 1 of the present invention, which is magnified 100 times by a scanning microscope, FIG. 4B is a graph showing the composition of FIG. 4A by EDS (Energy Dispersive Spectroscopy) Graph.
Fig. 5A is a photograph of a FeCrAl-Ni porous body manufactured by the second embodiment of the present invention, which is magnified 100 times by a scanning microscope, Fig. 5B is a graph showing the composition of Fig. 5A by EDS (Energy Dispersive Spectroscopy) Graph.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

The embodiment of the present invention is characterized in that a binder is used in the process of coating the conductive powder itself on the porous metal body in the electrostatic powder coating method to secure a sufficient bonding force of the conductive powder adhered to the porous metal body, An electrostatic powder coating apparatus for a conductive powder using a binder, and a coating method therefor. To this end, a method for coating a metal porous body with an electrostatic powder using a binder solution will be described in detail, and a method for manufacturing a metal porous body coated with a conductive powder using the above apparatus will be described in detail. Porous coating of the conductive powder itself by the electrostatic powder coating method as in the embodiment of the present invention is one of the dry coating methods, which is compared with the wet coating. Here, the electrostatic powder refers to a state in which the conductive powder is charged with positive (+) charge or negative (-) charge.

There are various ways to charge the electrostatic powder by positive (+) or negative (-) charge and ionize. For example, a corona system, an ion implanter, a plasma ionizer, and the like can all be applied. In the electrostatic precipitator using the corona method, a DC high voltage is used, a suitable inequality electric field is formed from the collector electrode to the anode electrode and the discharge electrode to the cathode electrode, and the corona discharge in the electric field is used to charge the dust in the gas. This is a device for separating and collecting the charged particles by a Coulomb force on the dust collecting pole.

Corona discharge has a positive (+) corona discharge and a negative (-) corona discharge. The secondary corona discharge has lower corona discharge initiation voltage, higher spark discharge initiation voltage, and stability than the corona discharge. A larger electric field intensity can be obtained. Therefore, a general industrial electrostatic precipitator uses a secondary corona discharge.

The positive ions and the negative ions generated by the secondary corona discharge move toward the opposite polarity electrodes. At this time, since the ionization region is limited to the discharge electrode, that is, in the vicinity of the cathode, the cation has a short-distance stroke and the anion has a long-distance stroke. Therefore, most of the dust particles are charged with anions and moved to the anode, It is called an electrode collecting electrode. In addition, the cathode, which is a cathode, emits electrons for sustained discharge. In the charging method of dust particles, ions are energized by an electric field to collide with dust particles, and ions in the gas are charged and diffused by irregular thermal motion due to the law of gas molecular motion. There is diffusion charging in which dust is adhered to dust particles. The dust particles transferred to the electrode adhere to the surface of the electrode, which is again drained or washed, and dropped and collected.

FIG. 1 is a schematic view for explaining an electrostatic powder coating apparatus of conductive powder using a binder according to an embodiment of the present invention. Of course, the components of the present invention may be suitably arranged in other forms within the scope of the present invention. An example of a sub-corona method in which an electrostatic powder is charged with positive (+) or negative (-) charges and ionized by a charge (50) is shown here. In some cases, all of the above-described static corona, ion implanter, and plasma ionizing airways can be applied. At this time, the conductive powder applied to the embodiment of the present invention may be classified into three types. That is, the conductive powder is substantially the same material as the uncharged conductive powder, the charged conductive powder, and the dropped conductive powder, and the reference numerals thereof are indicated by 32, 52 and 86, respectively.

1, the coating apparatus of the present invention includes a powder storage tank 30, a charging unit 50, a support table 60, and a binder liquid supply unit 70 in a chamber 10, And a collecting tank (80). In some cases, the powder collecting bath 80 may be inside the chamber 10. The conductive powder 32 stored in the powder reservoir 30 is transferred to the charging unit 50 along the transfer pipe 34 by the blower 20 such as a gas blower. The charge section 50 receives a negative charge from a power supply 40 and allows negative charge to be received in the transferred conductive powder 32. The negative conductive powder 52 is injected toward the metal porous body 62 by the action of an electrostatic force on the surface of the grounded and positively charged metal porous body 62. At this time, the support table 60 can be moved left and right, front and rear, up and down with respect to the center of the bottom surface of the chamber 10, and may rotate by a predetermined angle in the ground direction as the case may be.

A part of the charged conductive powder 52 reaching the porous metal body 62 is coated on the porous metal body 62 disposed on the support 60 and the remaining uncoated conductive powder 86 is coated on the porous metal body 62 outside the chamber 10 And is collected in the powder collecting tank 80. The collected conductive powder 86 can be transferred to the powder reservoir 30 and recycled. At this time, the uncoated conductive powder 86 is electrically neutralized by the positive (+) charge of the porous metal body 62 and becomes electrically charged, thereby forming a non-charged undoped powder. The removed conductive powder 86 is sucked through the suction port 84 and stored in the powder collecting tank 80 by using the suction motor 82 for transferring the powder to the powder collecting tank 80.

The conductive powder 32 applied to the embodiment of the present invention may be any single element selected from among all types of metals or semiconductors which are conductive in powder form, or alloys thereof (including solid solution). For example, the conductive powder 32 may be selected from the group consisting of carbon (C), silicon (Si), conductive polymer, iron (Fe), chromium (Cr), nickel (Ni), cobalt (Co), platinum Pd), gold (Au), silver (Ag), barium (Ba), or an alloy of FeAl, FeNi, FeCr, FeCrAl and the like. More preferably, the metals and their alloys are even better. The conductive powder 32 may be manufactured by any method known in the art, and is not necessarily limited thereto.

The average particle diameter of the charged conductive powder 52 is determined based on the surface state of the porous metal body 62 and the charged particle size of the charged conductive powder ( 52, the injection speed V for injecting the charged conductive powder 52, the distance D between the charging part 50 and the metal porous body 62, and the injection flow rate F . The charged conductive powder 52 is substantially the same except for the difference between the non-charged conductive powder 32 and the charged powder. Here, the distance D refers to a horizontal distance parallel to the bottom surface of the chamber 10. Specifically, assuming that the injection time T and the average weight W of the conductive powder are constant in the same porous metal body 62, in order to obtain the desired coating layer, the injection speed V is increased or the distance D is small The size of the contained conductive powder 52 may be relatively small.

The jetting speed V can be determined by the applied voltage KV applied between the charging part 50 and the metal porous body 62 and the secondary speed at which the wind speed of the blower 20 affects the charging part 50 have. Further, the injection flow rate F can be adjusted by using the average weight W and the injection speed V. [ At this time, the injection time T and the average weight W of the conductive powder can be determined in advance. For example, the Ni metal porous body 62 having a pore size of 1,200 占 퐉 has a spraying time T of 15 seconds, an average weight W of 0.1 g / cm2 and an ejecting speed V of 50 m2 / And the distance D is 10 cm to 50 cm, the average particle diameter of the conductive powder 52 is preferably 100 nm to 1 mm.

When the average particle diameter of the conductive powder 52 is less than 100 nm, the amount of charge charged in the conductive powder 52 in the charge section 50 is small and the adhesion yield drops because it flows down without adhering to the porous metal body 62. If the average particle diameter of the conductive powder 52 is larger than 1 mm, the tendency of the metal powder to fall to the bottom of the chamber 10 due to gravity does not reach the porous metal member 62, and the adhesion yield is lowered. The applied voltage (KV) may range from 100V to 10,000KV. When the applied voltage (KV) is less than 100 V, the amount of charge charged in the conductive powder 52 in the charging part 50 is small and it is not attached to the metal porous body 62, The yield drops. Also, if it is greater than 10,000 KV, the voltage is too high, which can lead to a dangerous situation for the safety of work. Accordingly, when the stability of the operation is ensured, a higher voltage may be applied.

The charged conductive powder 52 applied to the embodiment of the present invention contains a negative (-) charge applied by the charge section 50. Here, the amount containing the negative (-) charge is called charge amount. On the other hand, the charge amount of the conductive powder 52 of the same size varies depending on the kind of the conductive powder 52, and in particular, the charge amount is larger than that of the insulating powder.

When charge is applied to powder sprayed with free positive (+) ions or free electrons (-) generated by high voltage, the charge amount varies depending on the size and type of powder, and the charge amount determines the kinetic energy amount of powder Energy is required so that the powder can be attached to the surface of the porous metal body. When the charged powder adheres to the surface of the porous metal body, the opposite charge is generated on the surface of the porous metal body, and this is called a "mirror charge effect". By this effect, the conductive powder adheres to the surface. Insulation powder is difficult to charge because of its high electrical resistance. Since the charge amount of the conductive powder 52 is larger than that of the insulating powder as described above, the adhesive force to be adhered to the positively charged metal porous article 62 is larger than that of the insulating powder.

Meanwhile, the conductive powder (32) of the present invention is a dry coating method in which the powder itself is charged and supplied to the porous metal body (62). Conventionally, the slurry coating mainly used includes additives such as an aqueous or non-aqueous solvent, a binder, a plasticizer, a dispersant, and a surfactant in the powder. Due to the above additives, the conventional wet coating has various problems such as difficult coating of a large area, slow coating speed, and environmental pollution. However, since the electrostatic powder coating method of the present invention is one of the dry coating methods, it is possible to solve all the problems caused by the conventional additives because there is no such additive.

The porous metal body 62 can be variously formed within the scope of the present invention, and is preferably a three-dimensional network or honeycomb form. The metal porous body 62 is preferably a metal of any type that is metallic, and may be a single metal of a single element or an alloy (including solid solution) of the single element. Specifically, the porous metal body 62 may be formed of a metal such as iron (Fe), nickel (Ni), aluminum (Al), titanium (Ti), copper The iron-based or nickel-based metal is at least one selected from the group consisting of pure metals, iron-chromium-based iron-nickel-based alloys, One can be the main component.

The position of the binder liquid supply unit 70 is not accurately determined, but it is preferable that the binder liquid supply unit 70 is provided near the support table 60. When the binder liquid is supplied to the porous metal body 62 having the conductive powder 52 attached thereto, the binding force between the conductive powders 52 is increased by the binder. As a result, even if the thickness of the conductive coating layer by the conductive powder 52 becomes thick, the conductive powder can be prevented from falling off. In this case, it is possible to secure a sufficient bonding force of the conductive powder adhered to the metal porous body 62, and to form a conductive coating layer which is laminated to a desired thickness. At this time, the method of supplying the binder solution to the conductive coating layer may be spraying, electro spraying, dip coating, or the like.

The binder liquid stored in the binder liquid supply unit 70 is obtained by dissolving or dispersing the binder in a non-aqueous or aqueous solvent. If necessary, the binder solution may further contain a dispersing agent such as a surfactant. The binder is selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, paraffin wax, carabona wax, chitosan, cellulose derivatives, starch derivatives, saccharide derivatives, polyethylene oxide, carrageenan, At least one selected from the group consisting of rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone and polyhydroxy compound can do. At this time, the solvent to be used is not particularly limited, but any one selected from C _n H _{2n + 1} OH system, acetone, hexane and water is preferable.

2 is a flowchart illustrating a conductive powder coating method using an electrostatic powder according to an embodiment of the present invention. Here, the coating apparatus of the present invention will be described with reference to FIG.

2, the conductive powder 32 is first introduced into the powder reservoir 30, and the porous metal body 62 is fixed to the support 60 (S10). At this time, the support table 60 is grounded. Thereafter, negative (-) charge is supplied from the power supply source 40 to the charge unit 50 (S20). The blower 20 is operated to send the conductive powder 32 to the charging unit 50 through the transfer pipe 34 (S30). At this time, the conductive powder 32 transferred to the charge section 50 is charged with negative (-) charge. The conductive powder 52 charged with the negative charge is injected from the charge section 50 to the porous metal body 62 (S40). The binder liquid is supplied from the binder liquid supply unit 70 to the conductive coating layer composed of the conductive powder 52 attached to the porous metal body 62 (S50). If desired, the metal porous body 62 fixed to the support table 60 can be moved left and right, front and rear, up and down, or rotated in the direction of the paper surface. As described above, by moving or rotating the porous metal body 62, it is possible to coat the large-area porous metal body 62 with the conductive powder 52.

Meanwhile, the thickness of the conductive coating layer coated with the conductive powder 52 on the porous metal body 62 can be controlled by repeating steps S 20 to S 50. Specifically, the negative charge is supplied to the charge unit (S20), the conductive powder is sent to the charge unit (S30), the conductive powder is injected into the porous metal body (S40), and (S50) of supplying the binder solution to the conductive coating layer can be repeatedly performed. By repeating steps S20 to S50, the thickness of the conductive coating layer coated on the porous metal body 62 can be freely adjusted. In addition, by supplying the binder liquid, the conductive coating layer having a larger thickness can be realized as compared with the case where the binder liquid is not supplied.

Subsequently, the removed conductive powder 86 that is not attached to the porous metal body 62 is collected by the suction motor 82 through the suction port 84 and stored in the powder collecting tank 80 (S60). At this time, a filter such as a HEPA filter may be attached to the suction port 84 to remove the conductive powder 86 having a proper size. Subsequently, the metal porous body 62 coated with the conductive powder 52 is degreased and sintered by various heat treatment furnaces such as a vacuum furnace, a reducing furnace, and an atmosphere furnace to be stabilized (S70). The step S60 of collecting the dropped conductive powder 86 may be applied after the step S50 is performed every time the steps S20 to S50 are repeated.

Hereinafter, the present invention will be described in more detail based on the following embodiments. The following examples are intended to illustrate but not limit the invention.

(Example 1)

In Example 1 of the present invention, an Fe powder having an average particle size of 45 占 퐉 (manufactured by Sekisui Chemical Co., Ltd.) was coated on a Ni porous body having a width of 200 mm × 300 mm and an average pore size of 1,200 μm to a thickness of 0.1 mm. Specifically, the charged Fe powder was injected at a spraying rate of 60 m < 2 > / hour to a Ni porous body at a distance of 30 cm at an applied voltage of 60 KV and a blowing gas pressure of 4 m & At this time, the Ni porous bodies were moved up and down and left and right at a speed of 5 cm / sec, and the injection time was 15 seconds. This process was repeated 5 times.

In order to improve the adhesion efficiency and homogeneity of the Fe powder during the above-described repetition, the binder solution of ₂ wt% binder (PVA1500 10 g + H ₂ O 500 mL) was sprayed onto the layer having the Fe powder attached thereto. The unattached Fe powder was collected and stored in a powder collecting tank for reuse. Thereafter, the Ni porous body coated with the Fe powder was heated to 700 ° C at 3 ° C / min, maintained at that temperature for 3 hours, degreased with air, and heated in a hydrogen atmosphere at 1,250 ° C at a rate of 10 ° C / And sintered for 1 hour. The sintered porous body was cooled to finally obtain an Fe-Ni porous body (Fig. 3). At this time, FIG. 3 is a photograph cut by approximately 150 * 70 mm in width * for measurement.

FIG. 4A is a photograph of a Fe-Ni porous body produced by Embodiment 1 of the present invention, which is magnified 100 times by a scanning microscope, FIG. 4B is a graph showing the composition of FIG. 4A by EDS (Energy Dispersive Spectroscopy) Graph.

4A and 4B, it was confirmed that the Fe powder having an average particle size of 45 μm was coated in a uniform size and shape. Further, the above-mentioned Ni porous body was coated with the Fe powder to a predetermined thickness.

(Example 2)

 In Example 2 of the present invention, FeCrAl powder (manufactured by Sandvik Osprey Co., Ltd., England) having an average particle diameter of 45 탆 was coated on a Ni porous body having a size of 200 * 300 mm in length × 200 mm and an average pore size of 1,200 탆 in a thickness of 0.1 mm . Specifically, the charged FeCrAl powder was sprayed onto the Ni porous body at a distance of 30 cm at an injection rate of 60 m 2 / hour at an applied voltage of 60 KV and a blowing gas pressure of 4 m 2 / hour. At this time, the Ni porous bodies were moved up and down and left and right at a speed of 5 cm / sec, and the injection time was 15 seconds. This process was repeated 5 times.

In order to improve the adhesion efficiency and homogeneity of the FeCrAl powder, a binder solution of ₂ wt% binder (PVA1500 10 g + H ₂ O 500 ml) was sprayed onto the layer having the FeCrAl powder attached thereto in the repeating process. The unattached FeCrAl powder was collected and stored in a powder collector for reuse. Thereafter, the Ni porous body coated with FeCrAl powder was heated to 700 ° C at a rate of 1 ° C / min, maintained for 3 hours, degreased in a hydrogen atmosphere, heated to 1,300 ° C in a hydrogen atmosphere at a rate of 10 ° C / Lt; / RTI > The sintered porous article was cooled to finally obtain a FeCrAl-Ni porous article similar to Fig.

Fig. 5A is a photograph of a FeCrAl-Ni porous body manufactured by the second embodiment of the present invention, which is magnified 100 times by a scanning microscope, Fig. 5B is a graph showing the composition of Fig. 5A by EDS (Energy Dispersive Spectroscopy) It is a graph

5A and 5B, it was confirmed that the FeCrAl powder having an average particle size of 45 μm was coated in a uniform size and shape. Further, the FeCrAl powder was coated to a predetermined thickness on the used Ni porous body.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention. It is possible.

10; Chamber 20; air blower
30; Powder reservoir 32; Conductive powder
40; A power supply 50; Whole
52; A charged conductive powder 60; support fixture
62; A metal porous body 70; Binder solution supply part
80; Powder collecting tank 82; Suction motor
84; Suction port 86; The dropped conductive powder

Claims (19)

A supporting base to which the porous metal body is fixed and charged with the first type of charge;
A charge portion for charging the conductive powder coated on the porous metal body with a charge of a second type opposite in polarity to the charge of the first type;
A power supply for supplying the charge of the second type to the charge portion;
A powder reservoir for storing the conductive powder for sending to the load; And
And a binder liquid supply unit for supplying a binder liquid for enhancing a binding force between the conductive powders to a conductive coating layer made of the conductive powder coated on the porous metal body,
The conductive powder charged in the charging part has electrical conductivity and is electrically neutralized when it comes in contact with the porous metal body. The conductive powder is attached to the porous metal body by its own charge, and the average particle diameter is 1 to 1,000 μm , And a composite layer comprising a coating layer of the conductive powder and a layer of the binder is present on the porous metal body. The electrostatic powder coating apparatus according to claim 1, wherein the charge of the first form is a positive charge or a negative charge. The electrostatic powder coating apparatus according to claim 1, wherein the conductive powder is any one of a corona charging method, an ion implanter, and a plasma ionizer. The electrostatic powder coating apparatus according to claim 1, wherein the supporting table is rotated in at least one of up, down, left and right, front and rear directions or in a cylindrical shape. The electrostatic powder coating apparatus according to claim 1, wherein the voltage applied to the charge unit is 100V to 10,000KV. 2. The method according to claim 1, wherein the average particle diameter of the conductive powder is determined by a surface state of the porous metal body, an average weight (W) of the conductive powder, (V) of injecting the conductive powder, a distance (D) between the charge portion and the porous metal body, and an injection flow rate (F) of the conductive powder. Powder coating apparatus. delete The conductive powder according to claim 1, wherein the conductive powder is at least one selected from a single element selected from the group consisting of a conductive metal and a semiconductor, or an alloy thereof (including solid solution) Coating apparatus. The method of claim 8, wherein the conductive powder is selected from the group consisting of carbon (C), silicon (Si), a conductive polymer, iron (Fe), chromium (Cr), nickel (Ni), cobalt (Co), platinum Pd), gold (Au), silver (Ag), and barium (Ba), or an alloy thereof (including solid solution). Coating apparatus. The electrostatic powder coating apparatus according to claim 1, wherein the porous metal body is at least one selected from a single metal consisting of a single element or an alloy thereof (including solid solution). The metal porous body according to claim 10, wherein the porous metal body is one of Fe, Ni, Al, Ti, Cu, noble metal (Ag, Au, Pt, Pd) Wherein the binder is at least one selected from the group consisting of silver, gold and silver. The electrostatic powder coating apparatus according to claim 1, wherein the binder liquid stored in the binder liquid supply unit is a binder dissolved or dispersed in a non-aqueous or aqueous solvent. 13. The method of claim 12, wherein the binder is selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, paraffin wax, carabona wax, chitosan, cellulose derivatives, starch derivatives, Selected from the group consisting of alginates, carrageenan, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymers, carbopol, polyamines, polyquaternary compounds, polyvinylpyrrolidone, polyhydroxy compounds Wherein the binder is at least one selected from the group consisting of silver, silver, silver, gold, silver, silver, silver, silver, silver, and silver. Charging conductive powder into a powder reservoir and fixing the porous metal body to a support supported by the first type of charge;
Supplying a charge of a second type opposite in polarity from the charge of the first type to the charge portion from a power source;
Sending the conductive powder stored in the powder reservoir to the lower portion;
Injecting the conductive powder charged with the charge of the second type into the porous metal body at the charge portion; And
And supplying a binder solution for enhancing a bonding force between the conductive powders to the conductive coating layer coated with the conductive powder on the porous metal body,
The conductive powder charged in the charging part has electrical conductivity and is electrically neutralized when it comes in contact with the porous metal body. The conductive powder is attached to the porous metal body by its own charge, and has an average particle diameter of 1 탆 to 1,000 탆 , And spraying the conductive powder onto the porous metal body so that the composite layer comprising the coating layer made of the conductive powder and the layer made of the binder is present in at least two layers and supplying the binder liquid And repeating the steps of: 15. The electrostatic powder coating method of conductive powder according to claim 14, wherein the charge of the first form is a positive charge or a negative charge. 15. The electrostatic powder coating method of conductive powder according to claim 14, wherein the conductive powder is any one of a corona charging method, an ion implanter, and a plasma ionizer. The method according to claim 16, further comprising the steps of: supplying the charge of the second type to the charge portion; sending the conductive powder to the charge portion; injecting the conductive powder into the porous metal body; The method of any one of claims 1 to 3, wherein the binder is a binder. 15. The method of claim 14, wherein the binder is selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, paraffin wax, carabona wax, chitosan, cellulose derivatives, starch derivatives, Selected from the group consisting of alginates, carrageenan, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymers, carbopol, polyamines, polyquaternary compounds, polyvinylpyrrolidone, polyhydroxy compounds Wherein the binder is at least one selected from the group consisting of copper oxide, copper oxide, and copper oxide. 15. The electrostatic powder coating method of conductive powder using a binder according to claim 14, further comprising the step of collecting the removed conductive powder not attached to the porous metal body with a powder collecting tank.

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