JPH1099751A - Coating apparatus for water soluble paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lead uncoated paint mist not adhering to workpieces but floating in a coating booth to a recovery part by the synergistic effect of a weak wind air current flowing downward from almost the whole surface of a ceiling face of the coating booth and the uncoated paint's own weight. SOLUTION: Uncoated paint not adhering to workpieces 14 but floating in a coating booth 12 is led to a recovery part by the synergistic effect of a weak wind air current M flowing downward from a first blast pipe 22 formed on almost the whole surface of a ceiling face of the coating booth 12 and the uncoated paint's own weight. In an opposite position to paint jetting devices putting the workpieces 14 therebetween, a strong wind air current H flowing downward by a second blast part 26 is formed, and uncoated paint mist is surely caught therein and is lead to the recovery part without adhering to the inner wall of the coating booth and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble paint coating apparatus, and more particularly to a water-soluble paint capable of efficiently collecting uncoated paint by reducing the adhesion of uncoated paint mist to the coating apparatus. Related to a coating device.

[0002]

2. Description of the Related Art Conventionally, an object to be coated (work) is continuously conveyed in a coating booth using a conveying means such as an overhead conveyor, and a paint spraying device or the like is used for the conveyed work. 2. Description of the Related Art A coating apparatus that performs coating by using a brush is widely used. At this time, a mist-like uncoated paint floating in the painting booth is generated without being applied to the work in the painting booth. It is necessary to prevent the uncoated paint mist from leaking out of the painting booth or re-adhering to the work, and it is desired to reliably collect the unpainted mist.

In recent years, uncoated paint mist that has not been applied to a workpiece during spray coating has recently been collected, and if necessary, subjected to a regeneration treatment such as filtration, and the recycled paint is used again for painting. Recycle use of paint has been proposed.
The unpainted paint mist is collected, for example, by using a water curtain formed by flowing a liquid (collection liquid) containing water as a main component on the surface of a metal plate suspended in a coating booth, and using the collection liquid. It is done by a water shower. In order to collect the uncoated paint mist by the water curtain or the water shower, an airflow is generated in a coating booth using a ventilation fan or the like, and the uncoated paint mist is put on the airflow, and the water curtain is placed on the water curtain. Together with the collision,
Lead to a water shower. The uncoated paint mist colliding with the water curtain flows down along with the metal plate together with the collecting liquid. Further, the uncoated paint mist that has not collided with the water curtain is knocked down by the collecting liquid when passing through the water shower together with the airflow. Then, the collection liquid containing the uncoated paint is collected by a collection tank or the like, and is again circulated and used in a water curtain, a water shower, or the like. When the circulating collected liquid reaches a predetermined concentration by the uncoated paint, it is separated into a concentrated liquid (paint) and a filtrate by a UF device or the like. Is used as a collection liquid.

[0004]

However, the conventional method of collecting unpainted paint mist using a water curtain has a problem that a large amount of unpainted paint remains on a metal plate serving as a curtain body and the recovery rate is poor. is there. In this case, it is conceivable to increase the amount of the collecting liquid used for the water curtain, but a problem occurs in that the collecting liquid circulation system and the collecting liquid regeneration system become large. Further, in order to efficiently collect the uncoated paint mist by using the water shower, there is a problem that a large amount of the collecting liquid is required as described above.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a water-soluble paint coating apparatus capable of efficiently collecting uncoated paint mist without coming into contact with a wall or the like. To provide.

[0006]

In order to achieve the above object, the present invention provides a painting booth for painting a work being conveyed by a water-soluble paint sprayed from a spray nozzle, and a ceiling of the painting booth. A first blower unit that is arranged on substantially the entire surface and forms a downward weak airflow in the coating booth; and a work blowing direction above the position facing the injection nozzle with the work interposed in the coating booth. A second blower section that extends and forms a downward strong wind current, and a collection section that is disposed immediately below the second blower section and collects uncoated paint mist caught in the strong wind stream and the weak wind stream. When,
It is characterized by including.

Here, the work is an electric product, an automobile, a construction material, other various mechanical products, daily necessities and the like. In addition, the painting booth is a closed space surrounded by a wall, and a gate for taking in and out a work suspended from a transport device such as an overhead conveyor is formed therein. A paint spray nozzle that sprays in a mist form is arranged, and sprays a paint mist to a workpiece that is being transported. The uncoated paint mist is a paint mist that has not been applied to the work, and a non-coated paint mist that is applied to a part other than the work is also referred to as an uncoated paint mist.

According to this configuration, the uncoated paint mist floating in the coating booth without being applied to the work is caused by a weak wind current flowing from almost the entire ceiling surface of the coating booth and the uncoated paint mist. Is guided to the recovery section by a synergistic effect with the self-weight. In particular, a strong airflow that flows downward is formed at the position opposite the paint spraying device across the work where the most unpainted paint mist exists, and the unpainted paint mist is surely caught in the strong wind and collected. Lead to. The uncoated paint mist caught in the air current can be recovered as a paint by, for example, colliding with a recovery liquid (for example, water) held in a recovery unit. in this way,
Since the unpainted paint mist can be guided to the collection section without making contact with the wall surface or the like in the coating booth, the collection efficiency is improved.

In order to achieve the above object, according to the present invention, the painting booth is arranged on a work transfer device having a substantially U-shaped trajectory including a forward pass and a return pass, and on the outside of the forward pass and the outside of the return pass of the work transfer device. Wherein the second blower separates the forward path and the return path of the U-shaped orbit by the strong wind current.

Here, if the work transfer device rotates the work at a connection portion between the forward path and the return path, for example, and changes the surface facing the paint spray nozzle, the front and back surfaces of the work can be coated.

According to this configuration, it is possible to completely separate the outward path and the return path by a strong wind for collecting uncoated paint mist, and it is possible to easily form a plurality of separated coating steps. At the same time, it is possible to reliably prevent the uncoated paint mist from re-adhering to the work, and to efficiently collect the uncoated paint mist and perform high-quality coating.

In order to achieve the above object, the present invention is characterized in that a liquid supply device for supplying cleaning water to a non-vertical portion of the inner wall of the coating booth is formed.

Here, the non-vertical portion of the inner wall of the coating booth is a slope portion such as a connecting portion between the bottom of the coating booth and the collecting section.

According to this configuration, the uncoated paint mist adhering to the non-vertical portion can be washed away with a small amount of washing water. The washing water may be constantly or intermittently supplied.

In order to achieve the above object, the present invention is characterized in that the blower nozzle of the second blower is formed so as to protrude to the vicinity of the upper end of the work to be conveyed.

According to this configuration, it is possible to prevent the strong wind current from spreading in the coating booth to generate a turbulent air flow, and the air flow from the blower nozzle at the portion of the non-painted surface side of the workpiece where the most unpainted paint mist is large. Since the jetting force of the paint becomes the strongest, it is possible to efficiently collect the uncoated paint mist.

In order to achieve the above object, the present invention is directed to the present invention, wherein the collecting section comprises a collecting liquid tank having a collecting liquid for solubilizing the collected uncoated paint mist, and a paint regenerating section for regenerating the paint from the collecting liquid. And the following.

According to this structure, the collected uncoated paint mist can be solubilized with a minimum amount of the recovery liquid, and can be efficiently removed from the high-concentration recovery liquid in the paint regeneration unit including the UF device and the like. Paint regeneration.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan sectional view of a water-soluble paint coating apparatus 10 of the present embodiment, and FIG. 2 is a side sectional view. The coating booth 12 constituting the coating apparatus 10 is a closed space surrounded by a wall, and in the case of the present embodiment, a work 14 (for example, an electric product, an automobile, a construction material, and the like) which is an object to be coated therein. Overhead conveyors (hereinafter simply referred to as conveyors) that have a substantially U-shaped track for suspending and sequentially transporting various machine products and daily necessities.
16 are arranged. Gates 12a and 12b are formed on one wall surface of the painting booth 12 for taking in and out the work suspended on the conveyor 16. A paint spraying device 18 that sprays the paint in the form of mist and sprays the work 14 on the outside of the forward path 16a and the backward path 16b of the conveyor 16 (outside of the painting booth 12) is disposed.
Only the paint spray nozzle 18a protrudes inside the paint booth 12. The paint spraying device 18 sprays paint when the work 14 is conveyed to the front of the paint spray nozzle 18a.

Work 1 conveyed by conveyor 16
No. 4 is coated on one side when transported on the outward path 16a, and 1 is located at the position of the connection portion A between the outward path 16a and the return path 16b.
The coating on the other side is performed while being reversed by 80 ° and transported on the return path 16b. In the present embodiment, the outward route 16
a, one paint spraying device 18 for each return route 16b
Is shown, but the number and position of the arrangement are appropriately selected according to the desired coating form. Further, the work 14 may be inverted at a position other than the connection portion A.

The characteristic features of the present embodiment are that a weak wind is formed downward from almost the entire ceiling surface of the coating booth and a strong wind is directed downward at a position opposed to the paint injection nozzle sandwiching the work. The uncoated paint mist that is formed and floats in the coating booth without being applied to the work is drawn into the airflow and guided to a collection unit arranged below the coating booth.

As shown in FIG. 2, the ceiling portion of the coating booth 12 is constituted by a first blower section 22 having a blower fan 20, and the first blower section 22 extends in the forward (return) transport direction of the workpiece 14. A second blower unit 26 having a blower fan 24 is disposed substantially at the center. The first air blower 22 constituting the ceiling of the coating booth 12 has a fiber filter 22a disposed on almost the entire surface of the ceiling, and a plurality of air lines are provided inside the fiber filter 22a. Then, a uniform downward weak wind current M is constantly generated throughout the interior of the coating booth 12. The flow velocity of the weak wind M is, for example, about 0.3 m / s. And
At this time, the capacity of the blower fan 20 depends on the painting booth 12.
Is about 220 m ³ / min, for example, when the size of the work is 4 m in the work transfer direction and the width is 3 m.

On the other hand, a second blowing section 26 extending in a line at substantially the center of the first blowing section 22 is provided with a blowing nozzle 26a protruding inside the coating booth 12 as shown in FIG. Have. As shown in FIG. 1, the blower nozzle 26a has a tubular shape with a rectangular cross section, and forms an air curtain that separates the forward path 16a and the backward path 16b by the strong wind N which is jetted downward. The blowing nozzle 26a is used for the work 1
4 near the upper end of, for example, 200 mm from the upper end of the work 14
It is desirable to protrude to a height of ~ 300 mm. By forming the blowing nozzle 26a so as to protrude and shorten the flow path of the strong wind airflow N, it is possible to prevent the strong wind airflow N from spreading right and left, and to prevent the work 14 in which the uncoated paint mist is present most. A stable strong downdraft is formed in the vicinity to efficiently collect uncoated paint mist. The flow rate of the strong wind N is, for example, about 1.0 m / s. And the capacity of the blower fan 24 at this time is
The length of the blowing nozzle 26a in the workpiece transfer direction is 3 m,
When the width is 100 mm, it is about 20 m ³ / min.

The strong wind N entrains the unpainted paint mist floating without painting on the work 14 in the painting booth 12 and guides it to the collection part disposed immediately below the blowing nozzle 26a. . Unpainted paint mist floating at a position distant from the workpiece drops due to a synergistic effect of the weak wind airflow M and the mist's own weight, and is eventually guided to the collection unit together with the strong wind airflow N. In the case of the present embodiment, an introduction duct 28 that is a part of a collection unit (details will be described later) is connected directly below the blower nozzle 26a. As shown in FIG. 1, the introduction duct 28
Along the bottom surface of the coating booth 12 from the end to the end, and the width thereof is preferably about 1.5 to 2 times the width of the blowing nozzle 26a. If necessary,
By setting the recovery unit side to a negative pressure, the recovery of the weak wind current M and the strong wind flow N can be performed more efficiently.

As described above, most of the uncoated paint mist sprayed from the paint spray nozzle 18a and not applied to the work 14 collides with the air curtain formed by the strong wind N which is formed on the back side of the work 14. The air is caught and collected in the air flow, and is guided to the collection section together with the air flow. The unpainted paint mist that has not collided with the strong wind N is guided downward by the weak wind M flowing through the entire interior of the coating booth 12, and heads toward the recovery unit. That is, the uncoated paint mist is guided to the collection unit without contacting or adhering to the wall surface or the like in the coating booth 12, so that the collection rate of the uncoated paint mist is improved. Further, since the air curtain by the strong wind N separates the forward path 16a and the backward path 16b, the unpainted paint mist on the forward path does not adhere to the work on the backward path, and vice versa. High-quality coating without "bumps" can be performed. Since only the weak airflow M exists on the coating surface side of the work 14, no turbulence is generated around the coating position and the coating quality is not affected.

FIG. 3 shows a schematic configuration of the recovery section 30 including the introduction duct 28 connected to the bottom of the coating booth 12. The other end of the collecting unit 30 is a collecting unit main body 32.
Is connected directly to the collector, and the airflow containing the uncoated paint mist is collected by the collection liquid (for example, water) in the collection liquid tank 34 of the collection unit main body 32.
34a. At this time, most of the uncoated paint mist is dissolved in the recovered liquid 34a. The uncoated paint mist reflected on the surface of the recovery liquid 34a together with the air current is collected in the recovery liquid tank 3
It is knocked down by a water shower 36 disposed inside 4 and mixed with the recovered liquid 34a. The airflow from which unpainted paint mist is separated is exhausted from the exhaust port 38.
At this time, in order to perform the exhaust efficiently, the exhaust fan 4
It is preferable to provide 0. In addition, the painting booth 12
In order to efficiently guide the weak wind airflow M and the strong wind airflow N to the recovery unit 30 in, it is desirable to appropriately adjust the exhaust capacity of the exhaust fan 40. Further, it is preferable to dispose an air filter 42 in order to reliably prevent the uncoated paint mist from being discharged into the atmosphere.

A paint regenerating unit 44 is provided in the collecting unit main body 32.
Is connected. The paint regenerating section 44 filters and separates the uncoated paint mist dissolved in the recovered liquid 34a from the recovered liquid 34a, regenerates the paint, and again paints the work 14 by the paint spraying device 18 (see FIG. 1). It is used for The recovered liquid 34a from which the paint has been separated is also regenerated by the paint regenerating section 44, returned to the recovered liquid tank 34 again, and used for collecting uncoated paint mist.

When regenerating the paint, first, the recovery liquid tank 34
The internal recovered liquid 34a is transferred to the replacement tank 46. In this case, the switching valve 48 is switched to disconnect the connection to the water shower 36, and the collection liquid tank 34 is
Connect to In the paint regenerating operation, for example, when the concentration of the recovered liquid 34a becomes higher than a predetermined value, at the end of the coating operation, or after the end of the predetermined period of the coating operation, the recovery valve 34 is moved to the replacement tank 46 by switching the switching valve 50. . Then, the recovered liquid 34a transferred to the replacement tank 46 is sequentially charged into the UF device 56 via the switching valve 52 and the pump 54, and is filtered. The filtered filtrate is discharged to a filtrate tank 58, and the concentrated liquid generated by the filtration is returned to the replacement tank 46 again. Then, the UF device 5
6 is repeated, and further concentration and discharge of the filtrate are performed. When the concentration is performed up to a predetermined value and reaches the same level as the paint, the switching valve 52 is switched and the concentrated liquid is transferred to the concentration tank 60, and the paint spray device 18 (see FIG. Returned to tank and reused for painting.

On the other hand, the filtrate discharged to the filtrate tank 58 and stored in a predetermined amount is supplied to the switching valve 62 and the water shower 3.
The water is pumped up by the pump 64 for use in the water shower 36. In this manner, the collected uncoated paint mist is made soluble in water with a minimum recovery liquid, and the paint recovery section including the UF device and the like performs efficient paint recovery from the high-concentration recovery liquid.

FIG. 4 shows a means for cleaning a non-vertical portion of the inner wall of the coating booth 12, for example, a slope 12c which is a narrowed portion at the bottom. As shown in FIG. 2, the flow of the weak wind M is a slope 12c at the bottom of the coating booth 12.
Is gently curved along the line and is guided to the introduction duct 28, so that a part of the uncoated paint mist that has been caught
May settle down. For this reason, the washing water (preferably, the collected liquid 34 in the collected liquid tank 34) is provided on the upstream side of the slope 12c.
a) is provided. The liquid supply device 68 includes a cleaning water supply pipe 68a disposed along the top of the slope 12c and a plurality of nozzles 68b formed in the cleaning water supply pipe 68a. Supply water. The supply of the cleaning water may be sprayed as long as the strength or timing does not affect the airflow inside the coating booth 12, but it is preferable to supply the cleaning water to such an extent that a film is formed by the cleaning water.

Thus, the uncoated paint mist adhering to the non-vertical portion can be washed away with a small amount of washing water.

In this embodiment, an example is shown in which a round conveyor having a substantially U-shaped track is used to separate the outward and return paths by a strong wind to perform two-step painting.
A round conveyor with a U-shaped track or a conveyor of another shape may be combined to form a plurality of coating processes separated by a strong wind, or a straight conveyor may be used to face the paint spray nozzle that sandwiches the work to be conveyed. Even when a strong wind is formed at the position, the same effect as that of the present embodiment can be obtained. The configurations of the coating booth, the collection unit, the paint regenerating unit, the washing water supply device, and the like are merely examples, and the same effects as those of the present embodiment can be obtained as long as the configurations have the same functions.

[0033]

As described above, according to the present invention,
The unpainted paint mist floating in the painting booth without being applied to the work is collected by the synergistic effect of the weak wind current flowing downward from almost the entire ceiling surface of the painting booth and the weight of the unpainted paint. Lead to. In addition, a strong wind flow is formed downward at the position opposite the paint spraying device, especially between the workpieces where the most unpainted paint mist exists, and the unpainted paint mist is surely caught in the strong wind current and collected. Lead to. As a result, the unpainted paint mist can be efficiently collected without adhering and remaining on the wall surface or the like in the paint collection booth.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of a water-soluble paint coating apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a water-soluble paint coating apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a configuration example of a recovery unit and a paint regenerating unit of the water-soluble paint coating apparatus according to the embodiment of the present invention.

FIG. 4 is an explanatory view showing an example of a means for cleaning a non-vertical portion of a coating booth of the water-soluble paint coating apparatus according to the embodiment of the present invention.

[Explanation of symbols]

10 painting equipment, 12 painting booth, 14 work, 1
6 overhead conveyor, 18 paint spraying device, 18
a paint spray nozzle, 20, 24 blower fan, 22
1st air blowing unit, 22a fiber filter, 26 second air blowing unit, 26a air blowing nozzle, 28 introduction duct, 30 recovery unit, 32 recovery unit main body, 34 recovery liquid tank, 34a recovery liquid, 36 water shower, 44 paint regeneration unit, 6
8 liquid supply device, M weak wind, N strong wind.

Claims (5)

[Claims] 1. A coating booth for coating a work being transported with a water-soluble paint sprayed from an injection nozzle, and disposed on substantially the entire ceiling surface of the coating booth, and a downwardly weak light is placed in the coating booth. A first blowing unit that forms a wind current, and a second blowing unit that extends along the work transfer direction above a position facing the injection nozzle with the work interposed in the coating booth and forms a downward strong wind flow. And a recovery unit disposed immediately below the second blower unit and recovering an uncoated paint mist caught in the strong wind current and the weak wind current. 2. The apparatus according to claim 1, wherein the painting booth comprises: a work transfer device having a substantially U-shaped trajectory including a forward pass and a return pass; and paints disposed outside the forward pass and the return pass of the work transfer device. A spray nozzle, wherein the second blower separates a forward path and a return path of the U-shaped track by the strong wind. 3. A coating apparatus for water-soluble paint according to claim 1, wherein a liquid supply apparatus for supplying cleaning water to a non-vertical portion of the inner wall of the coating booth is formed. . 4. The water-soluble apparatus according to claim 1, wherein the blowing nozzle of the second blowing unit is formed so as to protrude near the upper end of the workpiece to be transported. Paint coating equipment. 5. The apparatus according to claim 1, wherein the collecting section includes a collecting liquid tank having a collecting liquid for solubilizing the collected uncoated paint mist, and a collecting liquid from the collecting liquid. And a paint regenerating unit for regenerating water.