JPS62193664A - Method and device for coating granular particle - Google Patents

Abstract

PURPOSE:To coat granular particles in fixed width and uniform density by providing a vertical baffle plate in a box-type case, spraying a mixture of granular particles and a gas, allowing the mixture to descend along the baffle plate, and coating the particles. CONSTITUTION:With respect to the method for coating granular particles on an electrically conductive or nonconductive material to be coated, the mixture PA of granular particles P and a gas A is sprayed from the nozzle 2N of a granular particle coating gun in the horizontal direction. Consequently, the mixture is collided with the vertical baffle plates 3A and 3B in the box-type case 1 whose bottom surface is opened, and the gas and the granular particles are separated by inertial classification. The granular particles descend along the baffle plates 3A and 3B, and are coated on a material to be coated or a work W to be coated moved by a conveyer 6. The granular particles are easily and effectively coated on the surface of a cloth, etc., in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for applying powder to a conductive or non-conductive object.

BACKGROUND OF THE INVENTION Conventionally, the following methods have been used to apply powder and granular materials.

(1) Spray method Apply the powder using a spray gun.

(2) Fine powder method Powder and granules are spread and coated by falling by gravity using a fine powder machine.

(3) Powder is discharged by a 7-meter quantitative feeder and applied via a shooter.

Problems to be Solved Each of the above conventional methods has its own problems. That is, (1) Spray method: Since powder and granules are applied by air spray, the powder and granules are scattered in the air, which not only seriously harms the environmental hygiene of the work site, but also the parting lines on both sides of the pattern applied in a strip form. There is a lot of wasted material, such as blurred images.

(2) There is a lot of unevenness in the amount of powder spread, that is, the amount of powder applied, as a bridging phenomenon of powder and granules occurs in the hopper that supplies the powder to the pulverizer, or powder and granules adhere to the powder supply rotor. .

(3) The chute receives the powder and granules supplied from the quantitative feeder and applies it to the object to be coated via the chute.
Powder adheres or clumps on the shooter, which tends to cause uneven coating.

As described above, the conventional techniques harm the environment of the work site, cause uneven coating, and make the parting line of the coating band unclear.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for obtaining a coated band of powder and granular material with uniform density and clear parting lines without impairing the working environment in applying powder or granular material. .

Means for Solving the Problems In order to solve all the above-mentioned conventional problems, the inventors of the present invention took the conventional mechanism back to scratch and created a new concept from a completely different perspective.

The concept is the inertial separation method used to separate powder and gas. The inertial separation method involves colliding a mixture of powder and gas against a baffle plate, whereby the gas with relatively low inertia easily changes direction and leaves the baffle plate, but the gas with relatively large inertia changes direction easily and leaves the baffle plate. The powder particles are difficult to separate from the baffle plate and remain on the plate, so that they are separated from the gas.

The powder and granules separated in this way are attracted by the airflow descending along the baffle plate surface, and are also subjected to the force of gravity, and leave the baffle plate and flow downward. It descends. The amount of the falling powder and granules is the same as the ratio of the powder and gas ejected from the gun nozzle, that is, constant, and the powder and granules that are inertially separated and accumulated below the panful plate are separated by the gun nozzle. The gas ejected from the pipes accumulates statically without inducing turbulence. The motivation for the present invention is to focus on the above two points.

The gist of the present invention is to provide a vertical baffle plate in a box-shaped case, spray a mixture of powder and gas onto the plate using a powder spray gun, and separate the particles by inertial separation caused by the spray gun. This is a method and an apparatus for applying powder and granular material falling along a baffle plate onto an object placed below it or a moving object in the form of a band.

Next, the method of the present invention will be explained. Please refer to FIG. This figure shows a side sectional view of the invention. A mixture PA of powder P and gas A is sprayed laterally from the powder coating gun nozzle 2N, and vertical baffle plates 3A, 3B, etc. provided in a box-shaped case 1 with an open bottom are sprayed horizontally. The powder and granules separated from the gas by inertial separation are caused to collide with the surface of the baffle plate and fall onto the surface of the baffle plate. This is a method of applying powder or granules by collecting (P'') onto the surface of the object to be coated or onto the surface of the object M which is also moving downward on the conveyor belt 6 of the transfer device.

Next, the basic structure of the device according to the above invention will be explained. Please also refer to FIG.

The bottom of the box-shaped case 1 is open, and the measured side plate 1A
A mounting hole 1H for a powder coating gun nozzle 2N is opened in the upper part, and the gun nozzle is mounted facing inward.
is attached and connected to the intake device 10. Moreover, inside the box-shaped case, one or more vertical baffle plates 3A, 3B, .
... is attached, and the first panful plate 3A on the side of the gun nozzle 2N is located at a required distance dS''o from the side plate 1A of the case to which the gun nozzle is attached, and the upper part of the plate is connected to the inner surface of the case. They are installed closely together and with a required height h1'' below the bottom of the case.

Further, the second baffle plate 3B is the first baffle plate 3
A is installed at a position a certain required distance S1 further back from the position, with the upper part of the plate opened at a certain required height h2'', and the lower part thereof is installed in contact with the bottom of the case on the same line. The following baffle plates are installed by opening the upper and lower openings alternately.The bottom of the box-shaped case 1 has a certain necessary gap 11E I+, and below it is a coating table or a conveyor belt 6 of a transfer device, etc. is provided.

The gun nozzle 2.2N for powder coating is generally connected to the ejector 7 on the powder tank installed separately by a pipe (or tube). A grain hopper 8H and its ejector 8 may be provided in place of the gun nozzle 2.2N.

Furthermore, a pie break 9 can also be attached on the box-shaped case 1.

Next, the electrostatic coating method according to the present invention will be described. The electrostatic coating method according to the present invention includes a construction method. One is a conventional method in which fine particles of ejected powder are charged with a retachable corona pin 12A attached to a gun nozzle or the like. The other method is according to the present invention and is described in claim 2.

In contrast to the conventional charging method, which involves spraying, in the present invention, after being sprayed, the powder collides with the baffle plate, separates from the gas by inertia, and becomes a single substance that is descending on the baffle plate. Then, the powder or granules are charged with a corona pin, and a conductive coated object under the corona pin is used as a counter electrode, or a conductive metal is placed under a non-conductive and porous cloth, etc. The name of the painting uses the conveyor belt of the moving device as the counter electrode.
This is a method in which powder particles are effectively adhered and coated onto the surface of the object to be coated by corona discharge generated between these two electrodes.

Next, the basic structure based on the above-mentioned electrostatic powder coating method will be described.

In the electrostatic powder applicator according to the present invention, everything except electrical parts such as corona pins must be made of non-conductive material. The box-shaped case 11 and the baffle plates 13A, 13B shown in the upper part of FIG. 5 are all made of non-conductive material. However, if the object to be coated is non-conductive, it is necessary to make the coating table below the corona pin, the conveyor belt 16 of the transfer device, etc. conductive as a counter electrode of the corona pin. Furthermore, if the conveyor belt is non-conductive and has voids, such as a net-type belt, it is necessary to provide a conductive guide plate or the like below the net-type belt to serve as a counter electrode.

As a method of charging the powder, a conventional electrostatic powder coating gun nozzle equipped with a corona pin 12A is used, or a corona pin 1 is attached to the first baffle plate 13A.
5A and 15B are provided. Its position is at the top of the board (15
A) or the lower part (15B). Furthermore, it is also provided on the second baffle plate 13B (15C).

Action Please refer to Figure 1. Box-shaped case 1 with open bottom
Inside, a mixture PA of powder P and gas A is ejected laterally from the gun nozzles 2, 2N and collides with the baffle plate 3A. Then, the powder P of the mixture PA is inertially separated from the gas A and remains on the baffle plate 3A (
P′). Then, the powder P' gathers downward due to gravity and the downward flow of the gas, and the gas A holds the remaining powder and granules and flows out into the next room "CI+", and also flows into the second baffle in the same room. Upon impacting plate 3B, a second separation action is performed again.A third baffle plate is used if necessary.

As described above, the powder P' separated by inertia descends along the baffle plates 3A, 3B, . The granular material can be applied in a band shape.

The amount of powder separated from the gun nozzle is also constant, and therefore the amount of application is also constant.

Furthermore, if the inner width of the box-shaped case is also fixed, the width of the application of the powder or granules will also be constant, and a uniform density coated band of the powder or granules can be obtained.

It is desirable that the cross section of the coating band has a uniform thickness as shown in Fig. 2, but if it is concave or high as shown in Figs. 3 and 4, the gun nozzle This can be corrected by adjusting the spray pattern and positioning the baffle plate.

The separated gas X that has passed through the last baffle plate of the plurality of baffle plates enters the ``DP'' chamber and is sucked from the same chamber into the powder recovery device 10 through the intake hole 4. Due to the suction action, the inside of the box-shaped case 1 becomes negative pressure, and outside air is sucked in through the gap "E PA" at the bottom of the case 1. Therefore, the mixture PA of powder and gas inside the case leaks to the outside. does not occur at all.

Next, an explanation will be given of the effect when an electrostatic method is adopted in order to further enhance the coating effect.

When an electrostatic coating gun nozzle is used, the ejected powder particles are electrically charged and adhere to the surface of the object to be coated, as in the case of the conventional coating gun nozzle.

In the case of the method according to claim 2 of the present invention,
As shown in FIG. 5, a mixture PA of powder P and gas A ejected from the gun nozzle 12.
A, 13]3. The powder P' and the gas A' are inertially separated by colliding with..., and the powder P' left on the baffle plate is cured by the plate and descends on the plate surface. At this time, it is charged by corona pins 15A and 15B provided on the plate. At the same time, corona discharge occurs between the corona pin and the conductive conveyor belt or coating table provided below the conductive coated material or the non-conductive and porous cloth, etc. The charged particles are guided along the lines of electric force and deposited on the surface of a conductive coating material or a non-conductive and porous coating material (P"). It is possible to force it.

Example 1. Please refer to Figure 1. Screw-type gap adjusters 51, 5 are used for adjusting the auxiliary equipment inside and outside the box-shaped case 1 and the displacement "'E"' provided below it.
2.53.

The conveyor belt of the above transfer device is electrically conductive. conductive steel belt or non-conductive rubber. Any type of belt, such as a belt, is acceptable.

Part 2. See Figure 5. This is the basic structure of the electrostatic powder coating device, and is as described above. The corona pin on the baffle plate is located at the top (15A) of the baffle plate 13A or the bottom (15A) of the baffle plate 13A.
5B). Furthermore, the same applies to the top of the baffle plate 13B.

In that case, corona pins 15A and 15B.

To prevent powder from accumulating on the 15G fixture, it is necessary to avoid protrusions or provide an inclined surface on the top surface as shown in FIGS. 5 and 6. Alternatively, as the cross section is shown in the upper figure, insert the corona pin 15A1 into the lower end surface of the baffle plate 138, expose only the tip part downward, and connect the root with conductivity. There is also a structure.

When the object to be coated is electrically conductive, a corona discharge is generated between the counter electrodes of the various types of corona pins described above, and charged powder particles adhere to the surface of the object to be coated. In this case, the conveyor belt of the transfer device may be made of a non-conductive material, but it is necessary to provide the contact 17 so that the object to be coated is not grounded.

Part 3. See Figure 8. This is a case where a conductive conveyor bell opening 8 is used as the counter electrode of the corona pin. Stainless steel bell l- is a representative material. Although this device is applied to cloth and the like where the object to be coated is non-conductive and porous, it can also be used when the object to be coated is conductive. Corona pin 25A on panful plate 13A,
, 25A2.25A3. A corona discharge occurs between ...... and the conductive conveyor pel H=7, and the powder particles separated on the baffle plate fall along the plate and are charged by the corona pin, At the same time, it advances onto the conveyor belt along the electric lines of force, but since there is a non-conductive and void cloth W etc. above the conveyor belt, it adheres to the cloth.

Part 4. See Figures 9A and 9B. This example is part 3 above. A non-conductive net-type belt 27 is used instead of the conductive conveyor belt 18 in FIG. A conductive guide plate 26 (FIG. 9A is a front view of the circuit portion, and FIG. 9B is a side view thereof) is provided as a counter electrode for the corona pin.

Part 5. 1st. See Figure OA and Figure 10B.

The conveyor belt 37 in this example is a non-conductive multi-striped belt 37. A conductive guide plate 36 as a counter electrode is fixed below the multi-thread belt.

The gap 38 between the multi-thread belts becomes a path for the lines of electric force EF generated between the corner pin and the guide plate 1.

Part 6. See Figure 1. An ejector 8 is attached in place of the gun 2 shown in the figure. A hopper 8H is attached to the ejector, and the granular material in the hopper can be directly ejected.

Part 7. See Figure 1. A pie break 9 is attached to the upper plate 1T of a box-shaped case 1. By means of the vibrator, not only the powder particles adhering to the inside of the case but also the powder particles on the baffle plate can be completely removed and lowered.

Part 8. See Figure 11. Slide-type inner movable plates 41A and 41B are provided on the inside of both sides or one side of the box-shaped case.

By adjusting these intervals The application width of powder and granules can be adjusted. Ru.

Part 9. See Figure 1. The intake hole 4B is connected to the upper plate 1 of the D'' chamber.
It is installed on the T. This has the effect of minimizing the fall of the remaining powder and granules in the same room.

Effects of the Invention According to the method and apparatus of the present invention, by spraying a mixture of powder and gas onto a baffle plate in a box-shaped case with an open bottom, the powder and gas are inertially separated, and the The powder is caused to fall by gravity along the baffle plate and the inner wall of the case, and is coated in a belt shape with a constant width and uniform density on the surface of a cloth or the like moving below the case. Furthermore, by providing a corona pin on the baffle plate and providing a counter electrode below the cloth, etc., it is possible to more effectively apply the powder onto the surface of the cloth, etc.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the method of the present invention and a fragmented drawing of its basic structure. Fig. 2 is a cross-sectional view of a coating band applied uniformly. Fig. 3 is a cross-sectional view of a coating band applied to a hollow in the center. Fig. 4. Figure 5 is a cross-sectional view of the coating band applied on the middle and high sides.
The figure shows Example 2. FIG. 7 is a front view of the corona pin mounted on the baffle plate in Example 1. FIG. 8 is a side sectional view of the corona pin attached to the lower end surface of the baffle plate in Example 3. A side cross-sectional view of a conductive conveyor belt and cloth, etc. transferred on it.
FIG. 9A shows the fourth embodiment. Figure 5 "X'"-"
9B is a side cross-sectional view of the same figure as above.
X'° cross-sectional view. Figure 10B is a plan view of the same as above. Figure 11 is the eighth embodiment. Figure 5 "X"'-II
Side sectional view of + Explanation of main symbols 1... Box-shaped case 1A... Side plate of box-shaped case 2N... Gun nozzles for applying powder and granules 3A, 3B. ...Baffle plate 4...
... Intake pipe 6 ... Conveyor belt 11 ...
...Non-conductive box-shaped case 11A...Side plate of the non-conductive box-shaped case 12N...Gun nozzles for powder coating 13A, 13B,...Non-conductive Baffle plate 14...Intake pipe 15A,
15B, 15C, Corona Pier
16... Conveyor belt of misdirection 18...
... Conductive conveyor belt 26 ... Conductive guide plate 27 ... Net type conveyor belt 3
7...Multi-line conveyor belt CD...
... Corona discharge E ... Gap between the box-shaped case and the transfer device EF ... Lines of electric force M ...
...Conductive coating material W...Non-conductive and porous coating material PA...Mixture of powder and gas '''S!... Distance between the front side plate and the first baffle plate inside the box-shaped case

Claims (1)

[Claims] 1. A baffle plate 3A provided in a box-shaped case 1 with an open bottom allows a mixture PA of powder P and gas A to be ejected laterally from a powder coating gun nozzle 2N. , 3B, . . . , so that the powder P′, which has been inertially separated from the gas, is caused to fall by gravity and the downward flow of gas flowing along the baffle plate surface and the inner wall surface of the box-shaped case. ,
A method for applying powder or granular material, characterized in that it is applied onto the surface of an object W placed below or moving below. 2. Baffle plates 13A, 13B provided in a box-shaped case 11 with an open bottom surface, which blows out a mixture PA of powder P and gas A laterally from the powder coating gun nozzle 12N,
The powder and granular material P', which has been inertially separated from the gas, is caused to fall by gravity and the downward flow of the gas flowing along the baffle plate surface and the inner wall surface of the box-shaped case. Corona pins 15A, 15B, 15C provided in the descending flow of the powder and granular material in the same direction as the flow,
. . . and a non-conductive and porous object W that moves above the counter electrode due to the corona discharge CD generated between the counter electrode or a conductive object to be applied instead of the counter electrode.
Alternatively, an electrostatic coating method for powder or granular material, characterized in that the powder or granular material is applied onto the surface of the conductive object M to be coated. 3. "Powder and granular material" described in claims 1 and 2
is "absorbent polymer powder". 4. The "subject to be coated" according to claim 1 is "a non-conductive and porous material such as woven or non-woven fabric, paper, etc." 5. a. Box-shaped cases 1 and b with open bottoms; a powder coating gun nozzle 2N is provided in the opening 1H at the top of one side plate 1A of the box-shaped case 1, facing inward and laterally; c. , one or more vertical baffle plates 3A, 3B, . , d. An intake pipe 4 connected to the intake device 10 is provided in the box-shaped case 1 after the baffle plate, and e. A slight distance "E" from the open bottom surface of the box-shaped case 1.
1. A powder coating device comprising: a plate or a transfer device 6 on which an object to be coated is placed; 6. a. Non-conductive box-shaped case 11 with an open bottom; b. Gun nozzle 12N for powder coating is provided in the upper opening 11H of one side plate 11A of the box-shaped case 11, facing inward and laterally. , c, one or more vertical non-conductive baffle plates 13A, 13B, provided in the box-shaped case 11 at a required distance "S_2" substantially perpendicular to the ejection direction of the gun nozzle 12N. d. One or more corona pins 15A, 15B, 1 are arranged downwardly on the surfaces of the non-conductive baffle plates 13A, 13B, . . . or on the lower end surfaces thereof.
5C, . A plate-shaped coating table or a conductive transfer device 16 is provided parallel to the open bottom part at a distance of "E_1" from the open bottom part, and an electrostatic type. Powder coating equipment. 7. The "gun nozzle for applying powder or granule" according to claims 2 and 6 is an "electrostatic gun nozzle for applying powder or granule". 8. "Conductor transfer device 1" as set forth in claim 6
6” is “conveyor belt 27 that is non-conductive and has voids”
and a conductive plate 26 which is a counter electrode to the corona pin on the baffle plate is provided below the conveyor belt. 9. "Conductor transfer device 1" as set forth in claim 6
6" is a "multi-strip type non-conductive conveyor belt 37". 10. Claims 1, 2, 5, and 6
The "gun nozzle for applying powder or granular material" described in the section is an "air powder or granular material ejector." 11. Claims 1, 2, 5, and 6
The "box-shaped case" described in the section is "box-shaped case with vibrator."