Electrostatic film forming apparatus

Abstract

To provide an improved electrostatic film forming apparatus adopted with a rubbing belt instead of a conventional roll brush.SOLUTION: An electrostatic film forming apparatus is constituted so as to attach a powder onto an object by electrostatic force. The electrostatic film forming apparatus includes: a screen 1 formed with a mesh 1a; a rubbing belt 3 for rubbing a powder onto the screen 1; a press head 5 for pressing the rubbing belt 3 onto the screen 1; a belt moving mechanism 7 for moving the rubbing belt 3 in a longitudinal direction; an electric power source DC for applying a voltage between the screen 1 and the object 100; and a hopper 10 for feeding the powder to the rubbing belt 3 or the screen 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrostatic film forming device that adheres powder such as edible powder or functional powder to an object by utilizing electrostatic force. [Background technology]

[0002] Electrostatic screen printing apparatuses are used for a variety of purposes, such as printing on food products and manufacturing industrial products. The principle of this electrostatic printing will be explained with reference to FIG. 33. As shown in FIG. 33, the electrostatic screen printing apparatus includes a conveyor 501 on which an object 500 is placed, a screen 502 having a mesh, a roll brush 503 on the screen 502, and a hopper 504 that supplies powder to the roll brush 503. The object 500 is moved by the conveyor 501 to a printing position below the screen 502.

[0003] The screen 502 is connected to the negative terminal of a DC power supply, and the conveyor 501 is connected to the positive terminal of the DC power supply and is also grounded. A high voltage is applied between the screen 502 and the conveyor 501 by the DC power supply, which creates an electrostatic field between the screen 502 and the object 500 on the conveyor 501.

[0004] Powder is supplied from a hopper 504 onto a rotating roll brush 503 and falls onto a screen 502. The powder on the screen 502 is rubbed into the mesh of the screen 502 by the rotating roll brush 503, passes through the mesh and is pushed out to the bottom of the screen 502. At this time, the powder becomes negatively charged due to friction with the rotating roll brush 503. Therefore, the powder is attracted to the grounded object 500 and adheres to the surface of the object 500, forming a film of uniform thickness on the object 500.

[0005] Because this type of electrostatic printing technology is capable of forming uniform powder films, it has recently begun to be used in the production of a variety of industrial products, including fuel cells, all-solid-state batteries, secondary batteries, and cosmetics. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-347221 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention provides an improved electrostatic deposition apparatus that employs a rubbing belt instead of the conventional roll brush. [Means for solving the problem]

[0008] In one aspect, an electrostatic film formation device is provided that adheres powder to an object by electrostatic force, the electrostatic film formation device comprising: a screen with a mesh formed thereon; a rubbing belt for rubbing the powder into the screen; a pressing head that presses the rubbing belt against the screen; a belt moving mechanism that moves the rubbing belt in its longitudinal direction; a power source that applies a voltage between the screen and the object; and a hopper that supplies the powder to the rubbing belt or the screen.

[0009] In one embodiment, the scrubbing belt is an endless belt, and the belt moving mechanism has a drive pulley and a driven pulley that support the scrubbing belt, and a pulley rotating mechanism that rotates the drive pulley. In one embodiment, the hopper is located above the rubbing belt and is arranged to supply the powder onto the rubbing belt. In one embodiment, the electrostatic film forming apparatus further includes a powder leveling member that levels the powder supplied from the hopper onto the rubbing belt. In one embodiment, the electrostatic film forming apparatus further includes a belt vibrating device that vibrates the rubbing belt together with the powder supplied onto the rubbing belt from the hopper. In one embodiment, the electrostatic film forming apparatus further includes a belt cover that prevents the powder supplied from the hopper onto the rubbing belt from falling off the rubbing belt, and the belt cover has a powder guide surface that extends along the outer surface of the rubbing belt. In one embodiment, the electrostatic film forming apparatus further includes a static eliminator that eliminates static electricity from the powder supplied onto the rubbing belt from the hopper. In one embodiment, the electrostatic film forming apparatus further includes a charge applying device that applies a charge to the powder supplied from the hopper onto the rubbing belt.

[0010] In one embodiment, the electrostatic deposition apparatus further includes a vacuum suction device that removes powder from the rubbing belt that has passed through the pressing head. In one embodiment, the electrostatic deposition apparatus further includes a pressure adjustment mechanism that moves the pressure head toward the screen and away from the screen. In one aspect, the pressure adjustment mechanism includes a tilt actuator that tilts the pressure head relative to the screen. In one embodiment, the tilting actuator is configured to tilt the pressing head in the longitudinal direction of the scrubbing belt. In one embodiment, the tilting actuator is configured to tilt the pressing head in the width direction of the scrubbing belt. In one aspect, the pressure head is a plurality of pressure heads, and the pressure adjustment mechanism is a plurality of pressure adjustment mechanisms respectively connected to the plurality of pressure heads. In one embodiment, the electrostatic deposition apparatus further includes a translational movement mechanism that moves the pressure head along the screen, and the translational movement mechanism is arranged to move the pressure head relative to the rubbing belt.

[0011] In one embodiment, the screens are a first screen and a second screen arranged above and below the object, the rubbing belts are a first rubbing belt and a second rubbing belt arranged above and below the object, the pressing heads are a first pressing head and a second pressing head arranged above and below the object, the belt moving mechanisms are a first belt moving mechanism and a second belt moving mechanism arranged above and below the object, and the hoppers are a first hopper and a second hopper arranged above the first rubbing belt and the second rubbing belt. In one embodiment, the screens are a first screen and a second screen arranged on either side of the object, the rubbing belts are a first rubbing belt and a second rubbing belt arranged on either side of the object, the pressing heads are a first pressing head and a second pressing head arranged on either side of the object, the belt moving mechanisms are a first belt moving mechanism and a second belt moving mechanism arranged on either side of the object, and the hoppers are a first hopper and a second hopper arranged above the first rubbing belt and the second rubbing belt.

[0012] In one embodiment, the hopper is a plurality of hoppers arranged above the rubbing belt. In one embodiment, the electrostatic film forming apparatus further includes a first moving mechanism that moves the rubbing belt, the pressing head, and the belt moving mechanism together parallel to the screen, and a second moving mechanism that moves the hopper parallel to the screen. In one embodiment, the rubbing belt is an end-ended belt, and the belt moving mechanism is configured to reciprocate the rubbing belt in its longitudinal direction. [Effects of the Invention]

[0013] Compared to the roll brush 503 shown in FIG. 33, the rubbing belt has a larger contact area with the screen, allowing the powder to be rubbed into the screen over a wider area. As a result, the efficiency of electrostatic application of powder is improved, and electrostatic application of powder can be completed in a shorter time. In addition, because the contact area between the rubbing belt and the screen is large, the screen is less likely to bend. As a result, the distance between the screen and the object becomes uniform, and a uniform electrostatic field can be formed between the screen and the object. Furthermore, the life of the screen is extended. The rubbing belt has a larger surface area than the roll brush 503 shown in Fig. 33. Therefore, the powder on the rubbing belt can be leveled before rubbing the powder into the screen, and excess powder on the rubbing belt can be removed with a vacuum suction device after the powder has been rubbed into the screen. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view showing an embodiment of an electrostatic film forming apparatus. [Figure 2] FIG. 2 is a side view of the electrostatic film forming apparatus shown in FIG. [Figure 3] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 4] FIG. 4 is a side view of the electrostatic film forming apparatus shown in FIG. [Figure 5] 10 is a diagram showing a state in which the pressure adjustment mechanism has moved the pressure head in a direction away from the screen via the support member. FIG. [Figure 6] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 7] 7(a) and 7(b) are diagrams illustrating the operation of the two tilt actuators. [Figure 8] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 9] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 10] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 11]FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 12] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 13] 11A and 11B are diagrams showing an embodiment of the pressure adjusting mechanism shown in FIG. 10. [Figure 14] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 15] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 16] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 17] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 18] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 19] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 20] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 21] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 22] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 23] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 24] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 25] FIG. 25 is a side view of the electrostatic film forming apparatus shown in FIG. 24. [Figure 26] 10A and 10B are diagrams illustrating the operation of a second moving mechanism that moves the hopper above the screen. [Figure 27] 10A and 10B are diagrams illustrating the operation of a first moving mechanism that moves the rubbing belt, the pressing head, and the belt moving mechanism along the screen. [Figure 28] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 29] FIG. 29 is a side view of the electrostatic film forming apparatus shown in FIG. [Figure 30] FIG. 1 is a front view showing an embodiment of a rubbing belt. [Figure 31] 31 is a cross-sectional view taken along line AA in FIG. 30. [Figure 32] FIG. 10 is a front view showing another embodiment of the electrostatic film forming apparatus. [Figure 33] FIG. 1 is a schematic diagram showing a conventional electrostatic film forming apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of one embodiment of an electrostatic film-forming apparatus, and FIG. 2 is a side view of the electrostatic film-forming apparatus shown in FIG. 1. The electrostatic film-forming apparatus includes a screen 1 having a mesh 1a formed thereon, a rubbing belt 3 for rubbing powder into the screen 1, a pressure head 5 for pressing the rubbing belt 3 against the screen 1, a belt movement mechanism 7 for moving the rubbing belt 3 in its longitudinal direction, a DC power source for applying a voltage between the screen 1 and an object 100, and a hopper 10 for supplying powder to the rubbing belt 3. Examples of powder include edible powders and functional powders. The object 100 is not particularly limited and may be food, or industrial products such as fuel cells, all-solid-state batteries, secondary batteries, and cosmetics. Electrostatic film-forming includes electrostatic coating.

[0016] The screen 1 is disposed above the target object 100. The mesh 1a of the screen 1 forms a plurality of through holes that allow the powder to pass through. The hopper 10 is located above the rubbing belt 3 and is arranged to supply the powder onto the rubbing belt 3. The rubbing belt 3 in this embodiment is an endless belt. The belt moving mechanism 7 has a drive pulley 12 and a driven pulley 13 that support the inside of the rubbing belt 3, and a pulley rotation mechanism 15 that rotates the drive pulley 12. The pulley rotation mechanism 15 is connected to the drive pulley 12. The pulley rotation mechanism 15 is composed of a motor and a torque transmission mechanism (e.g., a sprocket, a chain, etc.). The pulley rotation mechanism 15 may be composed of a motor directly connected to the drive pulley 12.

[0017] The drive pulley 12 and the driven pulley 13 are rotatably supported by a support member 20. The support member 20 extends horizontally, and the drive pulley 12 and the driven pulley 13 are supported at both ends of the support member 20. A first elongated hole 24 is formed at one end of the support member 20. The shaft of the driven pulley 13 is inserted into the first elongated hole 24 and is movable in the longitudinal direction of the first elongated hole 24. The driven pulley 13 is pushed in a direction away from the drive pulley 12 by a spring (not shown), and applies tension to the scrubbing belt 3. The driven pulley 13 in this embodiment functions as a tension pulley that applies tension to the scrubbing belt 3.

[0018] The pressing head 5 is disposed so as to press the rubbing belt 3 against the screen 1 from its inside. The pressing head 5 has a pressing plate 22 that comes into contact with the inner surface of the rubbing belt 3. The surface of the pressing plate 22 that comes into contact with the rubbing belt 3 is preferably made of a material with low friction resistance, such as Teflon (registered trademark).

[0019] The press head 5 is held by a support member 20. More specifically, the support member 20 has a second elongated hole 25 that extends in a direction perpendicular to the screen 1. The press head 5 is fixed to the support member 20 by a screw 26 that passes through the second elongated hole 25. When the screw 26 is loosened, the press head 5 becomes movable in a direction perpendicular to the screen 1. Therefore, the position of the press head 5 relative to the screen 1 can be adjusted by the second elongated hole 25 and the screw 26.

[0020] The rubbing belt 3, supported by a drive pulley 12 and a driven pulley 13, forms a flat top. A hopper 10 supplies powder to the flat top of the rubbing belt 3. The outer surface of the rubbing belt 3 is made of a soft porous material such as urethane sponge, and is configured so that the powder supplied from the hopper 10 can be held on the outer surface of the rubbing belt 3.

[0021] The hopper 10 includes a hopper box 30 that stores powder therein, a hopper roller 31 disposed inside the hopper box 30, and a hopper roller rotation mechanism 34 that rotates the hopper roller 31. An example of a material for the hopper roller 31 is urethane sponge. The hopper roller rotation mechanism 34 is composed of a motor and a torque transmission mechanism (e.g., a sprocket, a chain, etc.). The hopper roller rotation mechanism 34 may be composed of a motor directly connected to the hopper roller 31. A powder outlet 35 is formed at the bottom of the hopper box 30. The powder outlet 35 is a plurality of through holes or slits.

[0022] The screen 1 is connected to the negative pole of a power supply (voltage application device) DC, and the stage 102 on which the object 100 is placed is connected to the positive pole of the power supply DC. The positive pole of the power supply DC and the stage 102 are grounded. A high voltage is applied between the screen 1 and the stage 102 by the power supply DC, which creates an electrostatic field between the screen 1 and the object 100 on the stage 102.

[0023] When the pulley rotation mechanism 15 rotates the drive pulley 12, the rubbing belt 3 circulates while being supported by the drive pulley 12, the driven pulley 13, and the pressing head 5. Powder is supplied from a hopper 10 to the outer surface of the rubbing belt 3 and carried to the screen 1 by the rubbing belt 3. The powder is rubbed into the mesh 1a of the screen 1 by the rubbing belt 3 and pushed out to the other side of the screen 1. At this time, the powder becomes negatively charged due to friction with the moving rubbing belt 3. Therefore, the powder is attracted to the grounded object 100, adheres to the surface of the object 100, and forms a film of uniform thickness on the object 100. Some types of powder become positively charged when rubbed into the mesh 1a of the screen 1 by the rubbing belt 3. When using such powder, the screen 1 is connected to the positive terminal of a DC power supply, and the negative terminal of the DC power supply and the stage 102 are grounded.

[0024] The rubbing belt 3 has a larger contact area with the screen 1 than the roll brush 503 shown in FIG. 33, and can rub the powder into the screen 1 over a wider area. As a result, the efficiency of electrostatic application of the powder is improved, and the electrostatic application of the powder can be completed in a shorter time. Furthermore, since the contact area between the rubbing belt 3 and the screen 1 is large, the screen 1 is less likely to bend. As a result, the distance between the screen 1 and the object 100 becomes uniform, and a uniform electrostatic field can be formed between the screen 1 and the object 100. Furthermore, the life of the screen 1 is extended.

[0025] Fig. 3 is a front view showing another embodiment of the electrostatic film formation apparatus, and Fig. 4 is a side view of the electrostatic film formation apparatus shown in Fig. 3. The configuration and operation of this embodiment not specifically described are the same as those of the embodiment described with reference to Figs. 1 and 2, so redundant description will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a pressure adjustment mechanism 38 that moves the pressure head 5 in a direction toward the screen 1 and a direction away from the screen 1. In the embodiment shown in Fig. 3, the pressure adjustment mechanism 38 has an actuator such as a fluid actuator (e.g., an air cylinder) or an electric actuator.

[0026] The pressing adjustment mechanism 38 is connected to the support member 20. Two driven pulleys 13 are rotatably attached to both ends of the support member 20. The pressing head 5 is held by the support member 20. The electrostatic film forming apparatus further includes a tension pulley 39 that applies tension to the scrubbing belt 3. The tension pulley 39 is pressed against the inner surface of the scrubbing belt 3 by a spring (not shown). The drive pulley 12 is positioned at a distance from the two driven pulleys 13. The hopper 10 is positioned above the portion of the scrubbing belt 3 supported by the drive pulley 12.

[0027] The object 100 is transported by a conveyor 300. The conveyor 300 includes a conveyor belt 301 on which the object 100 is placed, a plurality of belt rollers 303 that support the conveyor belt 301, and a belt drive motor 305 that is connected to one of the plurality of belt rollers 303. The conveyor belt 301 on which the object 100 is placed is connected to the positive pole of a DC power supply. However, the configuration of the conveyor 300 is not limited to the embodiment shown in FIG. 3 as long as it can transport the object 100 and can be electrically connected to the positive pole (or negative pole) of the DC power supply.

[0028] 3 shows a state in which the pressure adjustment mechanism 38 is pressing the pressure head 5 toward the screen 1 via the support member 20. When the object 100 is present directly below the pressure head 5, the pressure head 5 presses the rubbing belt 3 against the screen 1, as shown in FIG. 3. The powder supplied from the hopper 10 is rubbed into the screen 1 by the rubbing belt 3, and is caused to move toward the object 100 by the electrostatic field formed between the screen 1 and the object 100, where it adheres to the surface of the object 100.

[0029] 5 is a diagram showing a state in which the pressing force adjustment mechanism 38 has moved the pressing head 5 in a direction away from the screen 1 via the support member 20. As shown in FIG. 4, when the object 100 conveyed by the conveyor 300 is not directly below the pressing head 5, the pressing force adjustment mechanism 38 moves the pressing head 5 in a direction away from the screen 1 via the support member 20. The rubbing belt 3 moves away from the screen 1, and rubbing of the powder into the screen 1 is stopped.

[0030] In this way, intermittent application of powder is possible by operating the pressure adjustment mechanism 38. In one embodiment, as shown in Fig. 3, continuous application of powder is also possible by maintaining a state in which the pressure adjustment mechanism 38 presses the pressure head 5 toward the screen 1 via the support member 20.

[0031] FIG. 6 is a front view showing another embodiment of an electrostatic film formation apparatus. The configuration and operation of this embodiment, unless otherwise specified, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a pressure adjustment mechanism 38 that moves the pressure head 5 toward and away from the screen 1. The pressure adjustment mechanism 38 includes a tilt actuator 41 that tilts the pressure head 5 relative to the screen 1. More specifically, the pressure adjustment mechanism 38 includes a pivot shaft 42 that supports the pressure head 5 so that it can tilt freely, and two tilt actuators 41 arranged on both sides of the pivot shaft 42. The pressure plate 22 of the pressure head 5 is curved and protrudes toward the screen 1.

[0032] The pressure adjustment mechanism 38 is disposed between the two driven pulleys 13. The drive pulley 12 and tension pulley 39 are disposed at a distance from these driven pulleys 13. The tension pulley 39 is pressed against the scrubbing belt 3 by a spring (not shown), thereby applying tension to the scrubbing belt 3. The hopper 10 is disposed above the portion of the scrubbing belt 3 supported by the tension pulley 39 and drive pulley 12.

[0033] 7(a) and 7(b) are diagrams illustrating the operation of the two tilting actuators 41. The two tilting actuators 41 are configured to tilt the pressing head 5 in the longitudinal direction of the scrubbing belt 3. That is, the two tilting actuators 41 tilt the pressing head 5 around a pivot shaft 42 that extends perpendicular to the longitudinal direction of the scrubbing belt 3.

[0034] In FIG. 7( a), the two tilting actuators 41 tilt the press head 5 in a first direction. The press plate 22 of the tilted press head 5 presses the scrubbing belt 3 against the screen 1, causing the powder to adhere to a first range R1 of the target 100. Next, as shown in FIG. 7( b), the two tilting actuators 41 tilt the press head 5 in a second direction opposite to the first direction. The press plate 22 of the tilted press head 5 presses the scrubbing belt 3 against the screen 1, causing the powder to adhere to a second range R2 of the target 100. As a result, the powder can be applied to the target 100 over a wide range that includes the first range R1 and the second range R2.

[0035] Specific examples of tilting actuators include a fluid actuator (e.g., an air cylinder) and an electric actuator. In the embodiment shown in Figures 6 and 7, the pressure adjustment mechanism 38 has two tilting actuators 41, but the configuration of the pressure adjustment mechanism 38 is not limited to this embodiment as long as it can tilt the pressure head 5 in the longitudinal direction of the scrubbing belt 3. For example, the pressure adjustment mechanism 38 may have only one tilting actuator 41 adjacent to the pivot shaft 42.

[0036] 8 and 9 are front views showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment that are not particularly described are the same as those of the embodiment described with reference to FIGS. 1 and 2, so redundant description will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a translational movement mechanism 45 that moves the pressure head 5 along the screen 1. The translational movement mechanism 45 is arranged to move the pressure head 5 relative to the rubbing belt 3. The position of the rubbing belt 3 is fixed.

[0037] The translational movement mechanism 45 has a translational actuator 46 connected to the pressing head 5 and a linear guide 47 that movably supports the pressing head 5. The linear guide 47 is parallel to the screen 1 and extends in the longitudinal direction of the scrubbing belt 3. Examples of the translational actuator 46 include a fluid actuator (for example, an air cylinder) and an electric actuator.

[0038] 8 and 9, the pressing head 5 is moved in the longitudinal direction of the scrubbing belt 3 (the moving direction of the scrubbing belt 3) by a translational actuator 46. The moving direction of the pressing head 5 is limited to a direction parallel to the screen 1 by a linear guide 47. In FIG. 8, the translational actuator 46 moves the pressing head 5 in a first direction. The pressing plate 22 of the pressing head 5 presses the scrubbing belt 3 against the screen 1, causing the powder to adhere to a first range R1 of the target 100.

[0039] Next, as shown in FIG. 9 , the translational actuator 46 moves the press head 5 in a second direction opposite to the first direction. The press plate 22 of the press head 5 presses the scrubbing belt 3 against the screen 1, causing the powder to adhere to the second range R2 of the target 100. As a result, the powder can be applied to the target 100 over a wide range, including the first range R1 and the second range R2. Furthermore, the powder application range can be changed depending on the movement distance of the press head 5. Conventionally, to apply powder over a wide range, it was necessary to move the hopper along with the roll brush. However, in this embodiment, only the press head 5 needs to be moved, and the position of the hopper 10 can be kept fixed. As a result, the overall mechanism of the device can be simplified.

[0040] 10 and 11 are front views showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment, unless otherwise specifically described, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore redundant description will be omitted. The electrostatic film formation apparatus of this embodiment has a plurality of pressure heads 5 and a plurality of pressure adjustment mechanisms 38 connected to the plurality of pressure heads 5, respectively. The plurality of pressure adjustment mechanisms 38 are fixed to the support member 20. Examples of the pressure adjustment mechanisms 38 include a fluid actuator (e.g., an air cylinder) and an electric actuator.

[0041] Each pressure head 5 is a pressure roller rotatably connected to a corresponding pressure adjustment mechanism 38. Therefore, the pressure head (pressure roller) 5 can roll and come into contact with the inner surface of the scrubbing belt 3. The multiple pressure adjustment mechanisms 38 are configured to independently move the multiple pressure heads 5 in a direction toward the screen 1 and a direction away from the screen 1. For example, the multiple pressure adjustment mechanisms 38 can move the multiple pressure heads 5 to different positions relative to the screen 1, and the multiple pressure heads 5 can press the scrubbing belt 3 against the screen 1 with different pressing pressures. Furthermore, some of the multiple pressure heads 5 may be separated from the scrubbing belt 3, and the remaining pressure heads 5 may press the scrubbing belt 3 against the screen 1.

[0042] In the example shown in FIG. 11 , the distances of the multiple pressing heads 5 from the screen 1 gradually decrease along the movement direction of the rubbing belt 3. The amount of powder pressed into the screen 1 by the rubbing belt 3 tends to be greater upstream than downstream in the movement direction of the rubbing belt 3. Therefore, as shown in FIG. 11 , by gradually decreasing the distances of the multiple pressing heads 5 from the screen 1, the amount of powder pressed into the screen 1 can be made uniform in the movement direction of the rubbing belt 3. As a result, a powder film of uniform thickness can be formed on the target object 100. Furthermore, the pressing pressure of the rubbing belt 3 against the screen 1 can be finely adjusted, allowing the powder to be applied to the target object 100 uniformly or with a desired thickness distribution.

[0043] 12 , the electrostatic film formation apparatus may further include a belt vibrating device 48 that vibrates the rubbing belt 3. The belt vibrating device 48 is in contact with the underside of the rubbing belt 3 at a position downstream of the hopper 10. The powder supplied onto the rubbing belt 3 from the hopper 10 is vibrated by the belt vibrating device 48 and penetrates into the rubbing belt 3. The powder is carried to a powder rubbing position by the rubbing belt 3, and the rubbing belt 3 is pressed against the screen 1 by a plurality of pressing heads 5.

[0044] 12, the distances of the multiple pressing heads 5 from the screen 1 gradually decrease along the direction of movement of the rubbing belt 3. The multiple pressing heads 5 arranged in this manner can first press the powder on the surface side of the rubbing belt 3 into the screen 1, and gradually press the powder on the inner side of the rubbing belt 3 into the screen 1. As a result, it is possible to adjust the thickness of the powder coating.

[0045] Fig. 13 is a diagram showing one embodiment of the pressure adjustment mechanism 38 shown in Fig. 10. Fig. 13 illustrates the pressure adjustment mechanism 38 as seen from the direction of movement of the scrubbing belt 3. The pressure adjustment mechanism 38 is equipped with two tilting actuators 51 that tilt the pressure head 5 relative to the screen 1. These tilting actuators 51 are configured to tilt the pressure head 5 in the width direction of the scrubbing belt 3.

[0046] The pressure head (pressure roller) 5 is rotatably held by a head holding part 53, and the two tilting actuators 51 are connected to the head holding part 53. The pressure adjustment mechanism 38 is equipped with a position adjustment mechanism 54 arranged between the two tilting actuators 51. This position adjustment mechanism 54 is connected to the head holding part 53 by a pivot shaft 55. The pivot shaft 55 extends in the longitudinal direction of the rubbing belt 3. While supported by the position adjustment mechanism 54, the head holding part 53 and the pressure head (pressure roller) 5 are tiltable in the width direction of the rubbing belt 3 (a direction perpendicular to the longitudinal direction of the rubbing belt 3).

[0047] The position adjustment mechanism 54 is fixed to the support member 20. The position adjustment mechanism 54 can change the position of the pressing head (pressing roller) 5 with respect to the screen 1. That is, the position adjustment mechanism 54 has a guide shaft 57 that extends perpendicular to the screen 1, a shaft holder 58 that holds the guide shaft 57, and a screw 59 that fixes the position of the guide shaft 57 with respect to the shaft holder 58. An end of the guide shaft 57 is connected to the center of the head holder 53 via a pivot shaft 55.

[0048] The shaft holder 58 is fixed to the support member 20. When the screw 59 is tightened, the position of the guide shaft 57 relative to the shaft holder 58 is fixed. Therefore, the position of the pressing head (pressing roller) 5 relative to the screen 1 is fixed. When the screw 59 is loosened, the guide shaft 57 becomes movable relative to the shaft holder 58, which allows the positions of the head holder 53 connected to the guide shaft 57 and the pressing head 5 relative to the screen 1 to be changed.

[0049] The two tilting actuators 51 are arranged on either side of the guide shaft 57 and are connected to the head holder 53 via a slide shaft 61. The slide shaft 61 is movably supported by a shaft guide 62 fixed to the support member 20. The two tilting actuators 51 can tilt the pressing head 5 in the width direction of the scrubbing belt 3 around a pivot shaft 55. In this embodiment, each tilting actuator 51 is an electric actuator equipped with a servo motor 51a and a ball screw mechanism 51b, but other types of actuators may also be used. For example, each actuator may be a fluid actuator such as an air cylinder.

[0050] According to this embodiment, the amount of powder applied in the width direction of the rubbing belt 3 can be adjusted.

[0051] Figure 14 is a front view showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment, which are not particularly described, are the same as those of the embodiment described with reference to Figures 1 and 2, so duplicated explanations will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a belt cover 65 that prevents powder supplied from the hopper 10 onto the rubbing belt 3 from falling from the rubbing belt 3. The belt cover 65 has a powder guide surface 65a that extends along the outer surface of the rubbing belt 3.

[0052] The powder guide surface 65a of the belt cover 65 prevents the powder from falling, so the rubbing belt 3 can stably transport the powder to the screen 1. As a result, the amount of powder rubbed into the screen 1 is stabilized, and a powder film of uniform thickness can be formed on the target object 100.

[0053] Figure 15 is a front view showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment, which will not be particularly described, are the same as those of the embodiment described with reference to Figures 1 and 2, so duplicated explanations will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a vacuum suction device 70 that removes powder from the rubbing belt 3 that has passed through the pressure head 5. The vacuum suction device 70 is disposed downstream of the pressure head 5 and upstream of the hopper 10 in the movement direction of the rubbing belt 3.

[0054] The vacuum suction device 70 can remove powder that has not been pushed into the screen 1 from the rubbing belt 3. After the rubbing belt 3 has been cleaned by the vacuum suction device 70, powder is supplied to the rubbing belt 3 from the hopper 10. As a result, the amount of powder carried to the screen 1 by the rubbing belt 3 is stabilized.

[0055] Figure 16 is a front view showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment that are not particularly described are the same as those of the embodiment described with reference to Figures 1 and 2, so duplicated descriptions will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a powder leveling member 73 that levels the powder supplied from the hopper 10 onto the rubbing belt 3. The powder leveling member 73 is disposed above the rubbing belt 3. The powder leveling member 73 is held by a leveling member holder 74. The powder leveling member 73 is disposed downstream of the hopper 10 and upstream of the pressing head 5 in the movement direction of the rubbing belt 3.

[0056] The powder leveling member 73 is a flexible plate that comes into contact with the outer surface of the rubbing belt 3. The powder leveling member 73 levels the powder supplied from the hopper 10 onto the rubbing belt 3, thereby stabilizing the amount of powder carried to the screen 1 by the rubbing belt 3.

[0057] FIG. 17 is a front view showing another embodiment of an electrostatic film formation apparatus. The configuration and operation of this embodiment, unless otherwise specified, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore, redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a first static eliminator 75 that eliminates static electricity from powder supplied from a hopper 10 onto the rubbing belt 3. The first static eliminator 75 is disposed downstream of the hopper 10 and upstream of the pressing head 5 in the direction of movement of the rubbing belt 3. The first static eliminator 75 is disposed opposite the outer surface of the rubbing belt 3. The first static eliminator 75 removes unnecessary charges from the powder, thereby stabilizing the charging of the powder due to friction between the rubbing belt 3 and the screen 1.

[0058] 17, a second static eliminator 76 may be further provided. The second static eliminator 76 is disposed downstream of the pressing head 5 and upstream of the hopper 10 in the moving direction of the scrubbing belt 3. The second static eliminator 76 is disposed opposite the outer surface of the scrubbing belt 3. The second static eliminator 76 can remove unnecessary charges from the surface of the scrubbing belt 3 that has been charged by friction with the screen 1.

[0059] Figure 18 is a front view showing another embodiment of an electrostatic film formation apparatus. The configuration and operation of this embodiment, which are not particularly described, are the same as those of the embodiment described with reference to Figures 1 and 2, and therefore, redundant description will be omitted. The electrostatic film formation apparatus of this embodiment is equipped with a power supply device 78 that applies electricity to powder supplied from a hopper 10 onto the rubbing belt 3. The power supply device 78 is disposed downstream of the hopper 10 and upstream of the pressing head 5 in the direction of movement of the rubbing belt 3. The power supply device 78 is disposed opposite the outer surface of the rubbing belt 3. The power supply device 78 can assist in charging the powder due to friction between the rubbing belt 3 and the screen 1.

[0060] 19 is a front view showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment, which are not particularly described, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore, redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a belt vibrating device 80 that vibrates the rubbing belt 3 together with the powder supplied onto the rubbing belt 3 from a hopper 10. The belt vibrating device 80 is disposed downstream of the hopper 10 and upstream of the pressing head 5 in the direction of movement of the rubbing belt 3. Furthermore, the belt vibrating device 80 contacts the inner surface of the rubbing belt 3.

[0061] The belt vibration device 80 vibrates the rubbing belt 3, thereby forcing the powder to enter the interior of the rubbing belt 3. For example, the powder penetrates within a range of 1 mm to 2 mm from the surface of the rubbing belt 3. Therefore, the powder is less likely to fall from the rubbing belt 3, and is carried by the rubbing belt 3 to the screen 1. When the powder reaches the screen 1, the pressing head 5 presses the rubbing belt 3 against the screen 1. The powder is pushed out of the rubbing belt 3 and rubbed into the screen 1.

[0062] Figure 20 is a front view showing another embodiment of the electrostatic film formation apparatus. The configuration and operation of this embodiment, which are not particularly described, are the same as those of the embodiment described with reference to Figures 1 and 2, so duplicated explanations will be omitted. The electrostatic film formation apparatus of this embodiment has multiple hoppers 10A, 10B. These hoppers 10A, 10B are arranged above the flat upper part of the rubbing belt 3. The hoppers 10A, 10B are arranged along the direction of movement of the rubbing belt 3.

[0063] The powder contained in the multiple hoppers 10A, 10B may be the same type of powder or different types of powder. If the same type of powder is contained, the amount of powder supplied can be increased, allowing a thick powder film to be formed on the target object 100. If necessary, only one of the multiple hoppers 10A, 10B may be operated.

[0064] When different types of powders are stored, the different powders can be applied to the target object 100 to form multiple layers of different powders. For example, as shown in FIG. 21(a), a first powder is first supplied from one of the hoppers 10A, 10B to the rubbing belt 3, and the powder is rubbed into the screen 1 by the rubbing belt 3, thereby forming a first layer of the first powder on the target object 100. Next, as shown in FIG. 21(b), a second powder is supplied from the other of the hoppers 10A, 10B to the rubbing belt 3, and the powder is rubbed into the screen 1 by the rubbing belt 3, thereby forming a second layer of the second powder on the first layer. Although two hoppers 10A, 10B are provided in FIGS. 20 and 21, three or more hoppers may be provided.

[0065] 22 is a front view showing another embodiment of an electrostatic film formation apparatus. The configuration and operation of this embodiment, unless otherwise specified, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a first screen 1A and a second screen 1B disposed above and below the target object 100, a first rubbing belt 3A and a second rubbing belt 3B disposed above and below the target object 100, a first pressing head 5A and a second pressing head 5B disposed above and below the target object 100, a first belt movement mechanism 7A and a second belt movement mechanism 7B disposed above and below the target object 100, and a first hopper 10A and a second hopper 10B disposed above the first rubbing belt 3A and the second rubbing belt 3B.

[0066] The target object 100 is held horizontally by a holding member 83. The negative pole of the power supply DC is connected to the first screen 1A and the second screen 1B, and the positive pole of the power supply DC is connected to the holding member 83 and grounded. The first screen 1A and the second screen 1B are arranged symmetrically with respect to the target object 100. The first rubbing belt 3A and the second rubbing belt 3B are also arranged symmetrically with respect to the target object 100. The first hopper 10A is arranged above the first rubbing belt 3A, and the second hopper 10B is arranged above the second rubbing belt 3B. According to this embodiment, powder can be applied to both sides of the target object 100 simultaneously.

[0067] 23 is a front view showing another embodiment of an electrostatic film formation apparatus. The configuration and operation of this embodiment, unless otherwise specified, are the same as those of the embodiment described with reference to FIGS. 1 and 2, and therefore redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a first screen 1A and a second screen 1B disposed on either side of the target object 100, a first scrubbing belt 3A and a second scrubbing belt 3B disposed on either side of the target object 100, a first pressing head 5A and a second pressing head 5B disposed on either side of the target object 100, a first belt moving mechanism 7A and a second belt moving mechanism 7B disposed on either side of the target object 100, and a first hopper 10A and a second hopper 10B disposed above the first scrubbing belt 3A and the second scrubbing belt 3B.

[0068] The target object 100 is held vertically by a holding member 83. The negative pole of the power supply DC is connected to the first screen 1A and the second screen 1B, and the positive pole of the power supply DC is connected to the holding member 83 and grounded. The first screen 1A and the second screen 1B are arranged symmetrically with respect to the target object 100. The first rubbing belt 3A and the second rubbing belt 3B are also arranged symmetrically with respect to the target object 100. The first hopper 10A is arranged above the first rubbing belt 3A, and the second hopper 10B is arranged above the second rubbing belt 3B. According to this embodiment, powder can be applied to both sides of the target object 100 simultaneously.

[0069] Fig. 24 is a front view showing another embodiment of the electrostatic film formation apparatus, and Fig. 25 is a side view of the electrostatic film formation apparatus shown in Fig. 24. The configuration and operation of this embodiment not specifically described are the same as those of the embodiment described with reference to Figs. 1 and 2, so redundant description will be omitted. The electrostatic film formation apparatus of this embodiment includes a first movement mechanism 91 that moves the scrubbing belt 3, the pressure head 5, and the belt movement mechanism 7 together parallel to the screen 1, and a second movement mechanism 92 that moves the hopper 10 parallel to the screen 1.

[0070] The electrostatic film formation apparatus of this embodiment is equipped with a pressure adjustment mechanism 38 connected to the pressure head 5. This pressure adjustment mechanism 38 is configured to move the pressure head 5 in a direction toward the screen 1 and a direction away from the screen 1. The pressure adjustment mechanism 38 is fixed to a support member 20 that rotatably supports the drive pulley 12 and the driven pulley 13 (tension pulley). When rubbing powder into the screen 1, the pressure adjustment mechanism 38 presses the rubbing belt 3 against the screen 1 with the pressure plate 22. When not rubbing powder into the screen 1, the pressure adjustment mechanism 38 lifts the pressure plate 22 to move the rubbing belt 3 away from the screen 1.

[0071] As shown in FIG. 25(a), the first moving mechanism 91 has a first linear actuator 95 and a first linear guide 96. The scrubbing belt 3, the pressing head 5, and the belt moving mechanism 7 (including the pulley rotating mechanism 15, the driving pulley 12, and the driven pulley 13) are connected to the first linear actuator 95 and the first linear guide 96. The first linear actuator 95 and the first linear guide 96 extend parallel to the screen 1. A first movable frame 97 on which the pulley rotating mechanism 15 is installed is movably supported by the first linear guide 96. The first linear actuator 95 is connected to the first movable frame 97 and moves the first movable frame 97 along the first linear guide 96.

[0072] The pulley rotating mechanism 15 is connected to the drive pulley 12. The pulley rotating mechanism 15 and the support member 20 are fixed to a first movable frame 97. Therefore, the first linear actuator 95 can move the pulley rotating mechanism 15, the support member 20, the pressure adjusting mechanism 38, the drive pulley 12, the driven pulley 13 (tension pulley), and the rubbing belt 3 along the first linear guide 96 (i.e., parallel to the screen 1). Examples of the first linear actuator 95 include an electric linear actuator (e.g., a ball screw actuator or a belt actuator) and a fluid linear actuator (e.g., an air cylinder).

[0073] As shown in FIG. 25(b), the second movement mechanism 92 has a second linear actuator 101 and a second linear guide 103 connected to the hopper 10. The second linear actuator 101 and the second linear guide 103 extend parallel to the screen 1. A second movable frame 105 on which the hopper roller rotation mechanism 34 is installed is movably supported by the second linear guide 103. The second linear actuator 101 is connected to the second movable frame 105 and moves the second movable frame 105 along the second linear guide 103.

[0074] The hopper roller rotation mechanism 34 is connected to the hopper roller 31. The hopper roller rotation mechanism 34 and the hopper box 30 are fixed to a second movable frame 105. Therefore, the second linear actuator 101 can move the hopper 10 including the hopper roller rotation mechanism 34, the hopper roller 31, and the hopper box 30 along the second linear guide 103 (i.e., parallel to the screen 1). Examples of the second linear actuator 101 include an electric linear actuator (e.g., a ball screw actuator or a belt actuator) and a fluid linear actuator (e.g., an air cylinder).

[0075] The first moving mechanism 91 and the second moving mechanism 92 are configured to operate independently. Therefore, the first moving mechanism 91 can move the scrubbing belt 3 parallel to the screen 1 independently of the hopper 10. Similarly, the second moving mechanism 92 can move the hopper 10 parallel to the screen 1 independently of the scrubbing belt 3.

[0076] Fig. 26 is a diagram illustrating the operation of the second moving mechanism 92 that moves the hopper 10 above the screen 1, and Fig. 27 is a diagram illustrating the operation of the first moving mechanism 91 that moves the rubbing belt 3, the pressing head 5, and the belt moving mechanism 7 along the screen 1. In this embodiment, the powder is supplied from the hopper 10 onto the screen 1.

[0077] As shown in FIG. 26 , first, the second moving mechanism 92 moves the hopper 10 above the screen 1 while supplying powder from the hopper 10 onto the screen 1. Before the second moving mechanism 92 moves the hopper 10 above the screen 1, the first moving mechanism 91 moves the rubbing belt 3, the pressing head 5, and the belt moving mechanism 7 outside the screen 1. The second moving mechanism 92 moves the hopper 10 within a desired range, so that the hopper 10 can supply powder to a desired range of the screen 1. In one embodiment, the second moving mechanism 92 may move the hopper 10 over the screen 1 multiple times while repeatedly supplying powder onto the screen 1.

[0078] As shown in FIG. 27, when the supply of powder from the hopper 10 to the screen 1 is completed, the second movement mechanism 92 moves the hopper 10 to a retracted position outside the screen 1. Next, the first movement mechanism 91 moves the rubbing belt 3, the pressing head 5, and the belt movement mechanism 7 above the screen 1. Then, while the first movement mechanism 91 moves the rubbing belt 3, the pressing head 5, and the belt movement mechanism 7 parallel to the screen 1, the rubbing belt 3 rubs the powder on the screen 1 into the mesh 1a of the screen 1. The powder adheres to the object 100 due to electrostatic force generated between the screen 1 and the object 100. According to this embodiment, it is possible to apply powder to a wide area of ​​the object 100.

[0079] Fig. 28 is a front view showing another embodiment of the electrostatic film formation apparatus, and Fig. 29 is a side view of the electrostatic film formation apparatus shown in Fig. 28. The configuration and operation of this embodiment not specifically described are the same as those of the embodiment described with reference to Figs. 24 to 27, so redundant description will be omitted. In this embodiment, the rubbing belt 3 is an end belt. The belt moving mechanism 110 is configured to move the rubbing belt 3 back and forth in its longitudinal direction.

[0080] The belt moving mechanism 110 includes a swing arm 111 that holds both ends of the scrubbing belt 3, a swing shaft 112 fixed to the center of the swing arm 111, and a swing motor 113 connected to the swing shaft 112. The swing motor 113 rotates the swing shaft 112 alternately clockwise and counterclockwise, thereby rotating the swing arm 111 alternately by a predetermined angle clockwise and counterclockwise around the swing shaft 112. Due to the movement of the swing arm 111, the scrubbing belt 3 held at both ends of the swing arm 111 moves back and forth in its longitudinal direction.

[0081] The pressing head 5 is connected to a pressing force adjustment mechanism 38. The pressing force adjustment mechanism 38 is configured to move the pressing head 5 in a direction toward the screen 1 and a direction away from the screen 1. Examples of the pressing force adjustment mechanism 38 include a fluid actuator (e.g., an air cylinder) and an electric actuator. The rubbing belt 3 is pressed against the mesh 1a of the screen 1 by the pressing plate 22 of the pressing head 5, and comes into sliding contact with the screen 1.

[0082] 29, in addition to the first moving mechanism 91 and the second moving mechanism 92, the electrostatic film formation apparatus further includes a third moving mechanism 120 that moves the rubbing belt 3, the pressure head 5, and the belt moving mechanism 7 in the width direction of the rubbing belt 3. The width direction of the rubbing belt 3 is parallel to the screen 1 and perpendicular to the direction in which the first moving mechanism 91 moves the rubbing belt 3, the pressure head 5, and the belt moving mechanism 110.

[0083] The third movement mechanism 120 has a third linear actuator 121 and a third linear guide 122 arranged on the first movable base 97, and a third movable base 123 held by the third linear guide 122. The swing motor 113 is installed on the third movable base 123, and the pressure adjustment mechanism 38 is fixed to the third movable base 123. The third linear guide 122 extends in the width direction of the scrubbing belt 3 and allows the third movable base 123 to move in the width direction of the scrubbing belt 3. The third linear actuator 121 is connected to the third movable base 123 and is configured to move the third movable base 123 as shown by the arrow. With this configuration, the third linear actuator 121 can move the third movable frame 123, the oscillating motor 113, the oscillating shaft 112, the oscillating arm 111, the rubbing belt 3, the pressure adjustment mechanism 38, and the pressure head 5 in the width direction of the rubbing belt 3.

[0084] The operations of supplying and rubbing in the powder in this embodiment are the same as those in the embodiment described with reference to Figures 26 and 27. In this embodiment, the third movement mechanism 120 can move the rubbing belt 3 in its width direction, thereby further expanding the powder application range.

[0085] FIG. 30 is a front view showing one embodiment of the rubbing belt 3 described with reference to FIGS. 1 to 29, and FIG. 31 is a cross-sectional view taken along line AA in FIG. 30. The rubbing belt 3 has a rubbing layer 131 for rubbing powder into the screen 1, a core layer 132 bonded to the rubbing layer 131, and a drive transmission layer 133 bonded to the core layer 132. The core layer 132 is sandwiched between the rubbing layer 131 and the drive transmission layer 133. The drive transmission layer 133 is a layer that comes into contact with the drive pulley 12. The rubbing layer 131, the core layer 132, and the drive transmission layer 133 are bonded together with an adhesive that maintains flexibility. For example, a rubber-based adhesive, an epoxy-based adhesive, a silicone-based adhesive, or the like that can exert adhesive strength while maintaining flexibility can be used.

[0086] The rubbing layer 131 is made of a porous material capable of retaining powder. For example, open-cell urethane sponge, which has good powder retention properties, can be used as the material for the rubbing layer 131. Other examples include velvet-like cloth and thin leather with a high surface roughness. The core layer 132 is made of a material that has high strength, excellent flexibility, and mechanical strength. For example, aramid-based blended fibers can be used for the core layer 132. As another example, the core layer 132 may be formed by weaving fibers such as nylon, polyester, cotton, and acrylic resin into a mesh pattern. The drive transmission layer 133 is made of a material that is highly abrasion-resistant and tough, flexible, and has high contact friction with the drive pulley 12. For example, nitrile rubber can be used as the material for the drive transmission layer 133.

[0087] The width and thickness of the rubbing belt 3 are not particularly limited. For example, the width of the rubbing belt 3 is within a range of 20 mm to 1000 mm, and the thickness of the rubbing belt 3 is within a range of 4 mm to 20 mm. The thickness of the rubbing layer 131 is within a range of 3 mm to 10 mm, for example. In one embodiment, as shown in FIG. 31 , the thickness of the rubbing layer 131 is greater than the thickness of the core layer 132 and the thickness of the drive transmission layer 133 so that the rubbing layer 131 can incorporate powder therein.

[0088] The rubbing belt 3 is made of an insulating material and has insulating properties. When the screen 1 is brought as close as possible to the object 100, the screen 1 is made of an insulating material. In that case, the rubbing belt 3 is made of a conductive material and is connected to a DC power source as shown in FIG. 32. By mixing a conductive material (e.g., conductive powder) into each of the above-mentioned layers that make up the rubbing belt 3, the rubbing belt 3 can be made conductive.

[0089] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0090] 1, 1A, 1B screens 1a mesh 3, 3A, 3B Rubbing Belt 5, 5A, 5B Pressing head 7, 7A, 7B Belt moving mechanism 10, 10A, 10B hopper 12 Drive pulley 13 Driven pulley 15 Pulley rotation mechanism 20 Support member 22 Pressing plate 24 First slot 25 Second oblong hole 26 screws 30 Hopper Box 31 Hopper Roller 34 Hopper roller rotation mechanism 38 Pressure adjustment mechanism 39 Tension pulley 41 Tilt Actuator 42 Pivot axis 45 Translation mechanism 46 Translational Actuator 47 Linear guide 48 Belt vibration device 51 Tilt Actuator 51a Servo motor 51b Ball screw mechanism 53 Head holder 54 Position adjustment mechanism 55 Pivot axis 57 Guide shaft 58 Shaft holding part 59 Screw 61 Slide shaft 62 Shaft guide 65 Belt cover 65a Powder guide surface 70 Vacuum suction device 73 Powder leveling material 74 Leveling member holding section 75 1st static eliminator 76 Second static eliminator 78 Electrifying device 80 Belt vibration device 83 Retaining member 91 1st movement mechanism 92 Second movement mechanism 95 First Linear Actuator 96 First linear guide 97 First Movable Platform 100 objects 101 Second linear actuator 102 Stages 103 Second linear guide 105 Second Movable Platform 110 Belt moving mechanism 111 Swing arm 112 Oscillating shaft 113 Oscillating motor 120 Third movement mechanism 121 Third Linear Actuator 122 Third Linear Guide 123 Third Movable Platform 131 Rubbing layer 132 Core layer 133 Drive Transmission Layer 300 Conveyor 301 Conveyor Belt 303 Belt Roller 305 Belt drive motor DC power supply

Claims

1. An electrostatic film forming apparatus that deposits powder onto an object by electrostatic force, a screen having a mesh formed thereon; a rubbing belt for rubbing the powder into the screen; a pressing head that presses the scrubbing belt against the screen; a belt moving mechanism for moving the rubbing belt in its longitudinal direction; a power supply for applying a voltage between the screen and the object; an electrostatic film forming apparatus comprising a hopper for supplying the powder to the rubbing belt or the screen;

2. The rubbing belt is an endless belt, 2. The electrostatic film forming apparatus according to claim 1, wherein the belt moving mechanism comprises a drive pulley and a driven pulley that support the scrubbing belt, and a pulley rotating mechanism that rotates the drive pulley.

3. 2. The electrostatic film forming apparatus according to claim 1, wherein the hopper is located above the rubbing belt and is arranged to supply the powder onto the rubbing belt.

4. 4. The electrostatic film forming apparatus according to claim 3, further comprising a powder leveling member that levels the powder supplied from the hopper onto the rubbing belt.

5. 4. The electrostatic film forming apparatus according to claim 3, further comprising a belt vibrating device for vibrating the rubbing belt together with the powder supplied onto the rubbing belt from the hopper.

6. 4. The electrostatic film forming apparatus of claim 3, further comprising a belt cover that prevents the powder supplied from the hopper onto the rubbing belt from falling off the rubbing belt, the belt cover having a powder guide surface extending along the outer surface of the rubbing belt.

7. 4. The electrostatic film forming apparatus according to claim 3, further comprising a static eliminator that eliminates static electricity from the powder supplied onto the rubbing belt from the hopper.

8. 4. The electrostatic film forming apparatus according to claim 3, further comprising a power applying device that applies a voltage to the powder supplied onto the rubbing belt from the hopper.

9. 2. The electrostatic film forming apparatus according to claim 1, further comprising a vacuum suction device for removing powder from the rubbing belt that has passed through the pressing head.

10. The electrostatic deposition apparatus according to claim 1 , further comprising a pressure adjusting mechanism for moving the pressure head in a direction toward the screen and a direction away from the screen.

11. The electrostatic deposition apparatus according to claim 10 , wherein the pressure adjustment mechanism includes a tilt actuator that tilts the pressure head relative to the screen.

12. The electrostatic deposition apparatus according to claim 11 , wherein the tilting actuator is configured to tilt the pressing head in the longitudinal direction of the scrubbing belt.

13. The electrostatic film forming apparatus according to claim 11 , wherein the tilting actuator is configured to tilt the pressing head in the width direction of the scrubbing belt.

14. the pressing head is a plurality of pressing heads, The electrostatic deposition apparatus according to claim 10 , wherein the pressure adjusting mechanism comprises a plurality of pressure adjusting mechanisms respectively connected to the plurality of pressure heads.

15. The screen further includes a translation mechanism that moves the pressing head along the screen, 2. The electrostatic film forming apparatus according to claim 1, wherein the translation mechanism is arranged to move the pressing head relative to the scrubbing belt.

16. the screens are a first screen and a second screen disposed above and below the object, the rubbing belts are a first rubbing belt and a second rubbing belt disposed above and below the object, the pressing heads are a first pressing head and a second pressing head disposed above and below the object, the belt moving mechanism includes a first belt moving mechanism and a second belt moving mechanism disposed above and below the object, 2. The electrostatic film forming apparatus according to claim 1, wherein the hoppers are a first hopper and a second hopper disposed above the first rubbing belt and the second rubbing belt.

17. the screens are a first screen and a second screen disposed on either side of the object, the rubbing belts are a first rubbing belt and a second rubbing belt disposed on both sides of the object, the pressing heads are a first pressing head and a second pressing head disposed on either side of the object, the belt moving mechanisms are a first belt moving mechanism and a second belt moving mechanism disposed on both sides of the object, 2. The electrostatic film forming apparatus according to claim 1, wherein the hoppers are a first hopper and a second hopper disposed above the first rubbing belt and the second rubbing belt.

18. The electrostatic film forming apparatus according to claim 1 , wherein the hopper is a plurality of hoppers arranged above the rubbing belt.

19. a first moving mechanism that moves the rubbing belt, the pressing head, and the belt moving mechanism together in parallel with the screen; The electrostatic deposition apparatus according to claim 1 , further comprising a second moving mechanism that moves the hopper parallel to the screen.

20. The rubbing belt is an end-ended belt, 2. The electrostatic film forming apparatus according to claim 1, wherein the belt moving mechanism is configured to move the rubbing belt back and forth in its longitudinal direction.

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