KR101503344B1 - Apparatus of forming metal porous body using electrostatic powder and method of coating by the apparatus - Google Patents

Abstract

The present invention provides an apparatus of forming a metal porous body using electrostatic powder and a coating method thereof for solving various problems including coating, easily, a contact area by excluding wet coating, performing rapid coating, causing environmental pollution, etc. The present invention includes: a support on which a porous body form formed with polymer material is fixed and which is charged with a first type charge; a charging unit which charges metal powder coated on the porous body form with a charge having a polarity opposite to the first type charge; a power supplying source which supplies a second type charge in the charging unit; a powder storage which stores metal powder for transferring the charging unit; and a first binder solution supplying unit which supplies first binder solution coated on the porous form. The charged metal powder is coated on the porous body form by using electrostatic force.

Description

TECHNICAL FIELD [0001] The present invention relates to a metal porous body forming apparatus using electrostatic powder and a coating method therefor,

The present invention relates to an apparatus for forming a porous metal body and a coating method thereof, and more particularly to an apparatus and a method for forming a porous body of a metal matrix by using a prefoam 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 safety of the ceramic material, and the process 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 .

Conventionally, a porous metal body is formed on a polymer foam by a wet coating method such as wash coating, electrostatic spraying, and slurry coating. For example, slurry coating is a method of coating a polymer foam with a slurry obtained by mixing a metal powder with an appropriate ratio of an aqueous or non-aqueous solvent, a binder, a plasticizer, a dispersant, a surfactant, and the like . The electrostatic spraying is performed by injecting a colloid mixed with an aqueous or non-aqueous solvent, a binder, a surfactant, and the like into a capillary nozzle and spraying a droplet with electrostatic force of several tens kV between the nozzle and the substrate. Thereby forming a porous metal body. However, the wet coating method has various problems such as difficult coating of a large area, slow coating speed, and environmental pollution.

The object of the present invention is to provide a metal porous body forming apparatus using an electrostatic powder which solves various problems such as easy coating of a large area by eliminating wet coating, Coating method.

In order to achieve the above object, the present invention provides a porous metal body forming apparatus using an electrostatic powder, comprising: a porous substrate made of a polymeric material to which a porous substrate is adhered, a support member charged with a first type of charge, and a metal powder coated on the porous foam, And a charge that charges the second type of charge opposite in polarity to the charge. And a powder reservoir for storing the metal powder to be supplied to the charge unit and a power supply source for supplying the charge of the second type to the charge unit. And a first binder liquid supply unit for supplying a first binder liquid coated on the porous foam. The charge of the second type may be negative (-) charge.

In the apparatus of the present invention, the metal powder may be used as any one of, or a combination of, a corona system, an ion implanter, and a plasma ionizer. The support can be moved in at least one of up and down, right and left, forward and backward, or can rotate in a cylindrical shape. The voltage applied to the charge portion is preferably 100 V to 10,000 KV. The average particle size of the metal powder is determined by the surface state of the porous foam, the average weight (W) of the metal powder, and the average particle size of the metal powder at the bottom part when the injection time (T) (V) of spraying, a distance (D) between the charging part and the porous foam, and an injection flow rate (F) of the metal powder. The average particle diameter of the metal powder may be 100 nm to 1 mm.

In the preferred apparatus of the present invention, the metal powder may be any single element selected from the metals having conductivity, or alloys thereof (including solid solution). Preferably, the metal powder is selected from the group consisting of Fe, Cr, Ni, Co, Pt, Pd, Au, Ag, Ba), or alloys thereof (including solid solution) are preferable.

In the apparatus of the present invention, the porous foam may have a three-dimensional network structure or a honeycomb shape. At this time, the porous foam may be any one selected from polyurethane (PU) foam, polyurea foam, Ni coated PU foam, Fe coated PU foam and Cu coated PU foam. It is preferable that the first binder liquid stored in the first binder liquid supply portion is dissolved or dispersed in the non-aqueous or aqueous solvent. The first binder may be 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, At least one selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, One can be applied.

In a preferred embodiment of the present invention, the second binder liquid supply unit may further include a second binder liquid supply unit that supplies the second binder liquid to the coating layer formed of the metal powder of the porous foam. Here, the second binder solution may be the same as the first binder solution. It is preferable that the second binder solution stored in the second binder solution supplying portion is dissolved or dispersed in the non-aqueous or aqueous solvent. The second 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, At least one selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, One can be applied.

In order to solve the problems of the present invention, a method for forming a porous metal body using an electrostatic powder is such that metal powder is first introduced into a powder reservoir and the porous foam is fixed to a support supported by a first type of charge. Then, the surface of the porous foam is coated with the first binder liquid supplied to the first binder liquid supply portion rotor. And supplies a charge of a second type opposite in polarity to the charge of the first type from the power source to the charge portion. And the metal powder stored in the powder reservoir is sent to the lower part. And the metal powder charged with the charge of the second form is injected into the porous foam at the charge portion.

In the method of the present invention, it is possible to repeatedly perform the step of supplying the charge of the second type to the charge portion, sending the metal powder to the charge portion, and injecting the metal powder into the porous foam have. The support can be moved at least one of up and down, right and left, back and forth, and rotation. The first binder may be 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, At least one selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, One can be applied. The method may further include collecting the removed metal powder not attached to the porous foam by a powder collecting tank.

In the preferred method of the present invention, after the step of injecting the metal powder charged with the charge of the second form into the porous foam at the charge portion, the coating layer composed of the metal powder of the porous foam, And applying the second binder liquid by the supply unit. The method of claim 1, further comprising the steps of: supplying the charge of the second type to the charge portion; sending the metal powder to the charge portion; spraying the metal powder into the porous foam; The second binder liquid supply unit may repeatedly perform the step of applying the second binder liquid to the second binder liquid supply unit. The second 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, At least one selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, polyvinylpyrrolidone, One can be applied.

According to the apparatus for forming a porous metal body using the electrostatic powder and the coating method therefor, it is possible to easily coat a large area by coating a metal powder on a porous foam by an electrostatic powder coating method, And the like can be solved. Further, by utilizing the second binder, it is possible to secure a sufficient bonding force of the metal powder adhered to the porous foam, and to obtain a porous metal article which is uniformly laminated to a desired thickness.

FIG. 1 is a schematic view for explaining an apparatus for forming a porous metal body using electrostatic powder according to the present invention.
2 is a flowchart showing a method of forming a porous metal body using the electrostatic powder according to the present invention.
3 is a photograph of a Cu porous body according to Example 1 of the present invention.
FIG. 4A is a photograph of a Cu porous body manufactured according to Example 1 of the present invention, which is magnified 100 times by a scanning microscope, and FIG. 4B is a graph obtained by analyzing the composition of FIG. 4A by EDS (Energy Dispersive Spectroscopy) .
FIG. 5A is a photograph of the Fe porous body manufactured according to the second embodiment of the present invention magnified 100 times by a scanning microscope, and FIG. 5B is a graph obtained by analyzing the composition of FIG. 5A by EDS (Energy Dispersive Spectroscopy) .

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.

In the embodiment of the present invention, a metal powder is coated on a porous foam by an electrostatic powder coating method, whereby an electrostatic powder which is easy to be coated on a large area, has a high coating speed, And a coating method therefor. To this end, a method of coating the electrostatic powder on the porous foam will be described in detail, and a method for manufacturing the porous metal body by coating the metal powder with the electrostatic powder using the apparatus will be described in detail. Coating the metal powder itself on the porous foam by the electrostatic powdering 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 metal 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.

1 is a schematic view for explaining an apparatus for forming a porous metal body using electrostatic powder 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 is shown in which a charge 50 is charged by positive (+) charge or negative (-) charge and then charged with negative (-) charge. In some cases, all of the above-described static corona, ion implanter, and plasma ionizing airways can be applied. At this time, the metal powder applied to the embodiment of the present invention may be classified into three types. That is, the metal powder is substantially the same material as the uncharged metal powder, the charged metal powder, and the dropped metal powder, and the reference numerals thereof are indicated by 32, 52 and 86, respectively.

1, the coating apparatus of the present invention includes a chamber 10, a powder reservoir 30, a charging unit 50, a support 60, a first binder liquid supply unit 70, and a second binder liquid supply unit 72 And a powder collecting bath 80 outside the chamber 10. In some cases, the powder collecting bath 80 may be inside the chamber 10. The metal powder 32 stored in the powder reservoir 30 is conveyed to the charging unit 50 along the transfer pipe 34 by a 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 metal powder 32. The negatively charged metal powder 52 is injected toward the porous foam 62 by the action of an electrostatic force on the surface of the porous foam 62 that is grounded and positively charged. 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 in a cylindrical shape as the case may be.

A part of the charged metal powder 52 reaching the porous foam 62 is coated on the porous foam 62 disposed on the support 60 and the remaining uncoated metal powder 86 is coated on the porous metal foil 62 outside the chamber 10 And is collected in the powder collecting tank 80. The collected metal powder 86 can be transferred to the powder storage tank 30 and recycled. At this time, the uncoated metal powder 86 is electrically neutralized by the negative (-) charge of the porous foam 62, resulting in a negatively charged powder. The dropped metal powder 86 is sucked through the suction port 84 using a suction motor 82 for transferring to the powder collecting tank 80 and is stored in the powder collecting tank 80.

The porous foam 62 may be in various forms within the scope of the present invention, preferably in the form of a three-dimensional network or honeycomb. The polymeric material may be olyurethane (PU) foam, polyurea foam, Ni coated PU foam, Fe coated PU foam or Cu coated PU foam, and polyurethane is particularly preferable. The first binder supplied from the first binder liquid supply unit 70 may be coated on the surface of the porous foam 62 to facilitate coating of the metal powder 32 in the future. The position of the first binder liquid supplying portion 70 is not accurately determined, but it is preferable that the first binder liquid supplying portion 70 is provided near the supporting table 60.

The first binder liquid stored in the first binder liquid supply unit 70 is the binder dissolved or dispersed in a non-aqueous or aqueous solvent. If necessary, the first binder solution may further contain a dispersing agent such as a surfactant. Wherein the first binder is selected from the group consisting of polyvinyl alcohol, polyacetyl, polyethylene, polyethyleneimine, polyethylene glycol, polypropylene, parabin wax, carabona wax, chitosan, cellulose derivatives, starch derivatives, saccharide derivatives, polyethylene oxide, carrageenan, At least one selected from the group consisting of carnauba rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Can be applied. 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.

The metal powder 32 applied to the embodiment of the present invention 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 metal powder 32 may be at least one selected from the group consisting of Fe, Ni, Al, Ti, Cu, and noble metals (Ag, Au, Pt, Pd) 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 average particle diameter of the charged metal powder 52 is determined based on the surface state of the porous foam 62 and the charged state of the charged metal powder 62 in terms of a predetermined injection time T sprayed from the charge 50 to the porous foam 62 52, the injection speed V for injecting the charged metal powder 52, the distance D between the charging part 50 and the porous foam 62, and the injection flow rate F . The charged metal powder 52 is substantially the same except for the difference between uncharged metal powder 32 and charged. 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 metal powder are constant in the same porous foam 62, in order to obtain a desired coating layer, the injection speed V is increased or the distance D is small The size of the contained metal 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 porous foam 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 metal powder can be determined in advance. For example, in polyurethane porous foam 62 having 1,200 占 퐉 pores, the injection time T is 15 seconds, the average weight W of the metal powder is 0.1 g / cm2, the injection speed V is 50 m2 / Hour to 100 m < 2 > / hour, and the distance D is 10 cm to 50 cm, the average particle diameter of the metal powder 52 is preferably 100 nm to 1 mm.

If the average particle diameter of the metal powder 52 is less than 100 nm, the amount of charge charged in the metal powder 52 in the charge section 50 is small and the adhesion yield drops because it flows down without being adhered to the porous foam 62. If the average particle diameter of the metal powder 52 is larger than 1 mm, the tendency of the metal powder 52 to fall to the bottom of the chamber 10 due to gravity without becoming close to the porous foam 62 becomes large and the adhesion yield decreases. 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 metal powder 52 in the charge section 50 is small and it is not attached to the porous body foam 62 and falls off to the bottom of the chamber 10 by gravity 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 metal 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 metal powder 52 of the same size varies depending on the kind of the metal powder 52, and in particular, the charge amount is larger than that of the insulating powder. This is because the amount of charge varies depending on the size and type of powder when the powder charged with the free positive (+) ion or free electron (-) generated by high voltage is charged, So that 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 metal powder 52 is larger than that of the insulating powder in this way, the adhesion force of the metal powder 52 to the porous body 62 charged with positive electricity is larger than that of the insulating powder.

Meanwhile, the metal powder 32 of the present invention is a dry coating method in which the powder itself is charged and supplied to the porous body 62 coated with the first binder. 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.

Alternatively, the second binder may be supplied from the second binder liquid supply portion 72 onto the coating layer made of the metal powder 52 on the porous foam 62. The position of the second binder liquid supply part 72 is not accurately determined, but it is preferable that the second binder liquid supply part 72 is provided near the support table 60. When the second binder liquid is supplied to the porous foam 62 having the metal powder 52 attached thereto, the binding force between the metal powders 52 is increased by the second binder. Accordingly, it is possible to prevent the metal powder from falling off even though the thickness of the metal coating layer by the metal powder 52 becomes thick. In this case, it is possible to secure a sufficient bonding force of the metal powder adhering to the porous foam 62 to form a porous metal body to be laminated to a desired thickness. At this time, the method of supplying the binder solution to the metal coating layer may be spraying, electro spraying, dip coating, or the like.

The second binder liquid stored in the second binder liquid supply part (70) is obtained by dissolving or dispersing the binder in a non-aqueous or aqueous solvent. If necessary, the second binder solution may further contain a dispersing agent such as a surfactant. The second binder may be the same as the first binder supplied from the first binder liquid supply unit 70. Wherein the second 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 carnauba rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Can be applied. 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 metal 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. The metal porous body according to the embodiment of the present invention can be divided into two cases. That is, it can be divided into 1 when the second binder is not supplied to the coating layer made of the metal powder 52 and 2 when the second binder is supplied. At this time, the case 2 in which the second binder is supplied can be selectively applied.

2, the metal powder 32 is first introduced into the powder reservoir 30, and the porous foam 62 is fixed to the support 60 (S10). At this time, the support table 60 is grounded. Thereafter, the first binder is applied to the porous foam 62 through the first binder liquid supplied from the first binder liquid supply unit 70 (S20). (-) charge from the power supply source 40 to the charge unit 50 (S30). The blower 20 is operated to send the metal powder 32 to the charging unit 50 through the transfer pipe 34 (S40). At this time, the metal powder 32 transferred to the charging unit 50 is charged with negative (-) charge. The metal powder 52 charged with the negative charge is injected into the porous foam 62 from the charging part 50 at step S50. If necessary, the porous foam 62 fixed to the support table 60 can be moved left and right, back and forth, up and down, or rotated in the direction of the paper surface. As described above, the porous foam 62 having a large area can be coated with the metal powder 52 by moving or rotating the porous foam 62.

Meanwhile, the thickness of the metal coating layer coated with the metal powder 52 on the porous foam 62 may be adjusted by repeating steps S30 to S50. Specifically, the step (S30) of supplying the positive charge to the charge unit, the step (S40) of sending the metal powder to the charge unit, and the step (S50) of spraying the metal powder into the porous foam It can be done repeatedly.

Optionally, the second binder liquid supply unit 72 supplies the second binder liquid to the metal coating layer made of the metal powder 52 attached to the porous foam 62 (S60). At this time, the thickness of the metal coating layer coated with the metal powder 52 on the porous foam 62 may be adjusted by repeating steps S30 to S60. Specifically, the negative charge is supplied to the charge unit (S30), the metal powder is sent to the charge unit (S40), the metal powder is injected into the porous foam (S50), and (S60) of supplying the second binder solution to the metal coating layer can be repeatedly performed. By repeating steps S30 to S60, the thickness of the metal coating layer coated on the porous foam 62 can be freely adjusted. In addition, by supplying the second binder liquid, the metal coating layer having a larger thickness can be realized, compared with the case where the second binder liquid is not supplied.

Subsequently, the removed metal powder 86 not attached to the porous foam 62 is collected by the suction motor 82 through the suction port 84 and stored in the powder collecting tank 80 (S70). At this time, a filter such as a HEPA filter may be attached to the suction port 84 to remove the metal powder 86 having a proper size. Subsequently, the porous foam 62 coated with the charged metal powder 52 is degassed and sintered by various heat treatment furnaces such as a vacuum furnace, a reducing furnace, and an atmosphere furnace to stabilize it (S80). The step S60 of collecting the dropped metal powder 86 may be applied after the step S50 or S60 is performed every time the steps S30 to S50 or S30 to S60 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. Here, the case where the second binder is supplied to the coating layer made of the metal powder on the porous foam is taken as an example.

(Example 1)

Example 1 of the present invention was a polyurethane porous foam having an average pore size of 4,000 mu m in width and 170 mu m in length and having a mean particle size of 45 mu m and a Cu powder (product of Changsha Co.) coated to a thickness of 0.1 mm. Specifically, a first binder solution of ₂ wt% binder (PVA1500 10 g + H ₂ O 500 mL) was sprayed onto the polyurethane foam. Then, the charged Cu powder was sprayed onto the polyurethane porous foam 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 porous foam was moved vertically and horizontally 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 Cu powder during the above-described repetition, the second binder solution of 4 wt% binder (PVA1500 10 g + H ₂ O 500 mL) was sprayed onto the layer having the Cu powder attached thereto . The unattached Cu powder was collected and stored in a powder collecting tank for reuse. Thereafter, the polyurethane foam coated with the Cu powder was heated to 700 ° C at 3 ° C / min, maintained at that temperature for 3 hours, degreased with air, and then heated in a hydrogen atmosphere at 1,000 ° C at 5 ° C / , And sintered for 3 hours. The sintered porous body was cooled to finally obtain a Cu porous body. 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 Cu porous body manufactured according to Example 1 of the present invention magnified 80 times by a scanning microscope, and FIG. 4B is a graph obtained by analyzing the composition of FIG. 4A by X-ray spectroscopy (EDS) .

Referring to FIGS. 4A and 4B, it was confirmed that Cu powder having an average particle size of 45 μm was coated in a uniform size and shape. Further, the polyurethane porous foam used was coated with the Cu powder to a certain thickness.

(Example 2)

In Example 1 of the present invention, an Fe powder having an average particle diameter of 45 mu m (manufactured by SWEET Co., Ltd.) was coated on a polyurethane porous foam having a width of 200 mm × 300 mm and an average pore size of 4,000 μm to a thickness of 0.1 mm . Specifically, a first binder solution of ₂ wt% binder (PVA1500 10 g + H ₂ O 500 mL) was sprayed onto the polyurethane foam. Then, the charged Fe powder was injected at a spraying rate of 60 m < 2 > / hour to a polyurethane porous foam 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 porous foam was moved vertically and horizontally 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 in the above-described repeating process, a second binder solution of 4 wt% binder (PVA1500 10 g + H ₂ O 500 mL) was sprayed onto the layer with the FeCrAl powder in the repeating process . The unattached Fe powder was collected and stored in a powder collecting tank for reuse. Thereafter, the polyurethane foam 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 then heated to 1,250 ° C at 10 ° C / min in a hydrogen atmosphere , And sintered for 1 hour. The sintered porous body was cooled to finally obtain a Fe porous body.

FIG. 5A is a photograph of the Fe porous body manufactured according to the second embodiment of the present invention, which is magnified 20 times by a scanning microscope, and FIG. 5B is a graph of the composition of FIG. 5A analyzed by X-ray spectroscopy (EDS, Energy Dispersive Spectroscopy) .

5A and 5B, it was confirmed that the Fe powder having an average particle diameter of 45 μm was coated in a uniform size and shape. In addition, the above-mentioned polyurethane porous foam was coated with the Fe powder to a certain thickness.

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; The first binder liquid supply portion
72; A second binder liquid supply unit 80; Powder collecting tank
82; A suction motor 84; Inlet
86; The dropped conductive powder

Claims (26)

A support member to which a porous foam made of a polymer material is adhered and charged with a first type of charge;
A charge portion for charging the metal powder coated on the porous foam 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 metal powder for sending to the load;
A first binder liquid supply unit for supplying a first binder liquid for facilitating coating of the metal powder coated on the porous foam; And
And a second binder liquid supply part for supplying a second binder liquid to the coating layer made of the metal powder on the porous foam,
The metal powder charged in the charge part is electrically neutralized when it is brought into contact with the coating layer of the support and the metal powder with electrical conductivity and the coating layer made of the metal powder grows by the charge of the metal powder itself, At least two layers of a composite layer comprising a coating layer composed of the metal powder and a layer composed of the second binder are present on the first binder formed on the porous foam. A metal porous body forming apparatus using the electrostatic powder. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the charge of the first form is a positive charge or a negative charge. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the metal powder is charged using any one of a corona system, an ion implanter and a plasma ionizer. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the support is moved in at least one of up and down, right and left, and back and forth, or rotated in a cylindrical shape. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein a voltage applied to the charge portion is 100 V to 10,000 KV. The method according to claim 1, wherein the average particle size of the metal powder is determined by a surface state of the porous foam, an average weight (W) of the metal powder, (V) of injecting the metal powder, a distance (D) between the charging part and the porous foam, and an injection flow rate (F) of the metal powder. Device. delete The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the metal powder is at least one selected from among a single element selected from the metals having conductivity, or an alloy thereof (including solid solution). The method of claim 8, wherein the metal powder is selected from the group consisting of Fe, Cr, Ni, Co, Pt, Pd, Au, Ag, Barium (Ba), or an alloy thereof (including a solid solution). The apparatus for forming a porous metal body according to claim 1, wherein the porous foam has a three-dimensional network structure or a honeycomb shape. 11. The electrostatic powder according to claim 10, wherein the porous foam is any one selected from polyurethane (PU) foam, polyurea foam, Ni coated PU foam, Ni foam, Fe coated Ni foam and Fe coated Ni- A metal porous body forming apparatus using the same. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the first binder liquid stored in the first binder liquid supply unit is dissolved or dispersed in a non-aqueous or aqueous solvent. 13. The method of claim 12, wherein the first 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, , Carrageenan, alginate, karaya rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Wherein the metal porous body is at least one selected from the group consisting of a metal powder and a metal powder. delete The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the second binder liquid is the same material as the first binder liquid. The apparatus for forming a porous metal body using electrostatic powder according to claim 1, wherein the second binder liquid stored in the second binder liquid supply unit is dissolved or dispersed in a non-aqueous or aqueous solvent. The method of claim 1, wherein the second 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, , Carrageenan, alginate, karaya rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Wherein the metal porous body is at least one selected from the group consisting of a metal powder and a metal powder. Introducing a metal powder into a powder reservoir and fixing the porous foam to a support supported by a first type of charge;
Coating a surface of the porous foam with a first binder liquid supplied with a first binder liquid supply portion rotor for facilitating coating of the metal powder;
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 metal powder stored in the powder reservoir to the lower portion; And
Injecting the metal powder charged with the charge of the second form into the porous foam at the charge portion; And
And applying a second binder liquid to a coating layer formed of the metal powder formed on the porous foam by a second binder liquid supply unit,
The metal powder charged in the charge part is electrically neutralized when it is brought into contact with the coating layer of the support and the metal powder with electrical conductivity and the coating layer made of the metal powder grows by the charge of the metal powder itself, 1 to 1,000 탆, and the metal powder is formed on the first binder formed on the porous foam so that the composite layer composed of the coating layer composed of the metal powder and the layer composed of the second binder is present in at least two layers, And repeating the step of applying the second binder liquid. The method of forming a porous metal body using the electrostatic powder according to claim 1, The method of forming a metal porous body using electrostatic powder according to claim 18, wherein the charge of the first form is a positive charge or a negative charge. 19. The method of forming a metal porous body according to claim 18, wherein the metal powder is charged using any one of a corona type, an ion implanter and a plasma ionizer. delete 19. The method of claim 18, wherein the first 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, , Carrageenan, alginate, karaya rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Wherein the metal powder is at least one selected from the group consisting of a metal powder and a metal powder. The method for forming a porous metal body according to claim 18, further comprising collecting the removed metal powder not attached to the porous foam by a powder collecting tank. delete 19. The method of claim 18, further comprising the steps of: supplying the charge of the second type to the charge portion; sending the metal powder to the charge portion; spraying the metal powder into the porous foam; Wherein the step of applying the second binder liquid to the coating layer made of powder by the second binder liquid supply unit is repeatedly performed. 19. The method of claim 18, wherein the second 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, , Carrageenan, alginate, karaya rubber, xanthan gum, guar gum, gelatin, algin, tragacanth, acrylamide polymer, carbopol, polyamine, polyquaternary compound, polyvinylpyrrolidone, polyhydroxy compound Wherein the metal powder is at least one selected from the group consisting of a metal powder and a metal powder.

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