JPS6259634B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder coating booth that utilizes static electricity.

This type of painting booth charges the object to be painted with positive static electricity as it passes through the painting room, and sprays powder paint charged with negative static electricity onto the surface of the object to be painted. This is a configuration in which it is attached.

However, in conventional painting booths of this type, the powder paint sprayed into the painting room is sucked and collected by a single suction means installed at the top, bottom, or side wall of the painting room, resulting in the following disadvantages: It was hot.

Since the air intake means intensively sucks the air inside the painting room, turbulent vortex flow is generated in the painting room, which may cause the powder paint sprayed near the object to be painted to be isolated from the object to be painted. Therefore, a certain amount of the powder coating, which is originally close enough to be attached to the object to be coated, is discharged without adhering to the object to be coated.

Particularly when the suction means is located at the bottom or side wall of the painting room, the speed of descent of the powder coating due to its own weight and the speed of injection from the paint injection gun are facilitated by the suction operation of the suction means, and therefore the powder The floating time of the body paint in the air becomes short, and the adhesion efficiency to the object to be coated becomes poor. For the reasons mentioned above, in order to attach the required amount of powder paint to the object to be coated, it is necessary to increase the amount of powder paint sprayed, so it is necessary to increase the amount of powder paint that is sprayed. The configuration is large, and therefore the installation cost and manufacturing price of the entire painting booth are high, and the amount of powder paint used is also large, and in addition, the operating cost of the painting booth and the cost for pollution prevention Equipment costs also increase.

The first object of the present invention is to suppress the turbulent vortex flow generated in the coating chamber to cause the powder coating to accumulate near the object to be coated, thereby causing the sprayed powder coating to adhere to the object to be coated. The goal is to improve efficiency.

The second object of the present invention is to reduce the descending speed of the powder coating in the coating chamber and the acceleration caused by injection, thereby extending the suspension time of the powder coating near the object to be coated, and thereby increasing the floating time of the powder coating in the vicinity of the object to be coated. The purpose is to improve the adhesion efficiency to the object to be coated.

The painting booth of the present invention will be explained below with reference to the accompanying drawings.

In the embodiment shown in FIGS. 1 and 2, a coating chamber 1 of the coating booth of the present invention is equipped with means for transporting objects 2 to be coated, such as a trolley conveyor 3, a paint spray gun 4, and a bottom surface of the coating chamber. A porous floor surface such as a mesh belt conveyor 5, an air blowing means for forming a laminar flow provided below the porous floor surface, such as a blowing air chamber 6, and a porous surface formed on the upper surface of the coating chamber 1. For example, mesh filter 7
An air intake means for forming a laminar flow, such as an air intake chamber 8, is provided above the porous surface. The trolley conveyor 3 is configured to suspend and transport the object 2 to be coated and to positively charge the object 2, and the injection gun 4 injects powder coating P onto the object 2 to be coated. The sprayer is configured to form a mist of paint P' around the object 2 to be painted, and to charge the paint P negatively during spraying.

The mesh belt conveyor 5 is selected to have a mesh that will not be clogged with the powder coating P, and is preferably constructed so that it can circulate in the direction in which the object to be coated 2 is transported or in the opposite direction. Moreover, a paint collecting means such as a brush 9 and an intake port 10 are provided at the ends in the transfer direction, whereby the powder paint P falling onto the mesh belt conveyor 5 is caught and collected.

The blowing air chamber 6 blows out clean air of uniform pressure from the many holes of the mesh belt conveyor 5 so that a laminar flow f is formed upward.The strength of this laminar flow is The laminar flow f is selected so as to effectively prevent the paint P from falling, and this laminar flow f weakens the falling speed of the powder paint P or blows it up toward the mesh filter 7 above.

The intake chamber 8 cooperates with the blowout air chamber 6 to form the laminar flow f, and the intake chamber 8 forms the laminar flow in the upper part of the painting chamber 1.

In the above, the paint collecting means is not necessary when the powder paint P is blown upward in its entirety, but it is provided for cleaning the inside of the painting room 1 and for cleaning the mesh belt conveyor 5. It is convenient to have it. Since the booth of the present invention is constructed as described above, the paint mist P' formed around the object 2 by the spray gun 4 gradually moves upward by the laminar flow f rising from below. Since the particles are moved or the falling speed is suppressed, the floating time in the coating room 1 becomes longer, and the chances of the charged powder coating particles adhering to the object 2 to be coated increase. This improves the adhesion efficiency of the powder coating P, and since the airflow that blows up the mist P′ is a laminar flow f, the turbulent vortex flow generated in the coating chamber can be reduced as much as possible. Therefore, since the mist P' covers the object 2 without being dispersed early, it is possible to improve the adhesion efficiency of the charged powder coating particles to the object 2.

In the booth of the present invention, the powder paint in the painting room 1 stays for a much longer time than in the past.
There is the advantage of being able to reduce the amount of powder coating to be injected, and this also has the advantage of reducing the overall size of the apparatus and reducing costs.

The booth of the present invention is as described above, but in order to most efficiently attach the powder coating P to the object 2 to be coated, the powder coating P is blown upward and transferred by the laminar flow f. In this case, excess powder paint is captured by the mesh filter 7 on the top surface.

The second invention of the present application is as described above, in which the ceiling of the painting room 1 is formed by a transition type filter surface constructed by, for example, the mesh filter 7 of a circulating type or a reciprocating type, and this filter surface is covered with a The powder coating material P is transferred in the traveling direction of the painted object 2 or in the opposite direction thereof, and a collection means for the powder coating material P, for example, an air intake device 11 is provided at the end of the filter surface in the transfer direction.

For the filter surface of the second invention, an endless belt type mesh filter 7 as shown in FIG. 3 may be used, or a reciprocating mesh filter 7 as shown in FIG. 4 may be used. .

Since the mesh filter 7 shown in FIG. 4 reciprocates between the take-up drums 12 and 13 and transfers the adsorbed powder paint P toward the suction device 11, it is used as a recovery means, that is, in this embodiment. In this case, one intake device 11 is required for each reel side, and the length of the mesh filter 7 is also 2 of the expanded dimension l.
More than twice as much is required.

The intake device 11 may be a combination of a brush 11a and an intake port 11b as shown in FIG.
In order to effectively prevent clogging of the filter surface,
As shown in FIG. 4, compressed air is injected from above onto the filter surface by the injection nozzle 11c, and powder paint P adhering to the filter surface is sucked from below, opposite to the injection nozzle 11c, through the intake port 11b. The preferred method is to

Since the booth of the second invention is like this,
The mesh filter 7 is moved from the drum 12 to the drum 13.
The excess powder paint P blown up from below is thereby captured, and the captured powder paint P is transferred to the intake device 11 as a recovery means, and then transferred to the mesh filter. After all of the powder paint P is wound onto the reel 13, the mesh filter 7 is moved from the drum 13 to the drum 12, and the excess powder paint P is removed as before.
can be captured and recovered.

Therefore, according to the present invention, paint can be collected by the filter surface, and at the same time, dust can be removed from the air in the painting chamber.

The filter surface used in the second invention,
That is, the mesh filter 7 of the embodiment requires a unit length that is at least twice the expanded dimension l for each color. If you set it to a multiple of the length of the equal unit so that it can be used for multiple colors,
Convenient when changing powder paint colors.

In other words, if you do this, even if you change the color, you can replace it with a new filter surface without cleaning the filter surface that was used before the color change, or you can replace it with a new filter surface that is the same as the color after the color change. This has the effect of allowing selective use of the filter surface.

In the above case, if an auxiliary electrode is provided in the coating chamber 1 and a corona discharge is generated by this, the powder coating particles floating in the coating chamber 1 will be recharged and will be applied to the object to be coated 2. Coating efficiency is further increased.

Furthermore, since the laminar flow f has the effect of forming an air curtain at both ends of the painting chamber 1, for example, the area where the laminar flow f is formed is placed in front and behind the painting chamber 1 so as to seal the interior of the painting chamber 1. It is desirable to expand this to

Since the booth of the present invention is as described above, it can be used with great effect for this kind of powder coating.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional side view of the painting booth of the present invention, FIG. 2 is a front view thereof, and FIGS. 3 and 4 are side views showing essential parts of the painting booth according to the second invention. In the figure, 1 is a painting room, 2 is an object to be painted, 3 is a trolley conveyor as a transportation means, 4 is a paint spray gun,
5 is a mesh belt conveyor as a porous floor surface, 6 is a blowing air chamber as an air blowing means, 7 is a mesh filter as a porous surface or filter surface, 8 is an intake chamber as an intake means,
Reference numeral 11 indicates an air intake device as a recovery means, reference numerals 12 and 13 indicate winding drums, P indicates a powder coating material, P' indicates a mist mass of coating material, and f indicates a laminar flow.

Claims (1)

[Scope of Claims] 1. A transport means for transporting a charged object to be coated, and an injection gun for spraying a powder coating material charged to the opposite polarity onto the object to be coated transferred by the transport means;
a porous floor surface forming the lower surface of the painting room; a porous surface forming the upper surface of the painting room facing the porous floor surface; and an air blowing means for blowing air from the porous floor surface of the painting room; an air intake means for sucking air from the porous surface, the air blowing means and the air intake means form a laminar flow from below to upward between the porous floor surface and the porous surface, and the laminar flow causes the coating to be coated. A powder coating booth characterized by being configured to extend the floating time of a powder coating mist formed near an object. 2. The powder coating booth according to claim 1, wherein the strength of the laminar flow is selected so as to attenuate the rate of descent of the powder coating within the coating chamber. 3. The powder coating booth according to claim 1, wherein the strength of the laminar flow is selected to raise the powder coating within the coating chamber. 4 Claim 1, characterized in that the porous floor surface is made of a mesh belt conveyor.
Booth for powder coating as described in section. 5. A transfer means for transferring the charged object to be coated, and an injection gun for spraying a powder coating material charged to the opposite polarity onto the object to be coated transferred by the transfer means;
a porous floor surface forming the lower surface of the painting room; a porous surface forming the upper surface of the painting room facing the porous floor surface; and an air blowing means for blowing air from the porous floor surface of the painting room; and a suction means for sucking air from the porous surface, the air blowing means and the suction means form a laminar flow from below upwards between the porous floor surface and the porous surface, and the laminar flow causes the object to be coated to be coated. In a powder coating booth that extends the suspension time of a powder coating mist formed near a powder coating, the laminar flow formed by the air blowing means and the air intake means causes the powder coating mist to extend. The porous surface on the upper surface of the coating chamber is constructed with a transfer type filter surface, and at the end of the filter surface in the transfer direction, there is a means for collecting powder paint adhering to the filter surface. A powder coating booth featuring a 6. The powder coating booth according to claim 5, wherein the filter surface is constituted by an endless belt type mesh filter. 7. The powder coating booth according to claim 5, wherein the filter surface is constituted by a mesh filter that reciprocates between two drums. 8 The mesh filter has a length that is a multiple of this unit length, with the unit length for each color being more than twice the expanded dimension, and each unit length has a different color. A powder coating booth according to claim 7, characterized in that it is configured to capture powder coating. 9. The recovery means includes an injection nozzle that injects air from above to below the mesh filter, and is provided below the mesh filter to face the injection nozzle and to suck in the powder paint adhering to the mesh filter. 6. The powder coating booth according to claim 5, characterized in that the powder coating booth comprises an air intake port.