JPH0824735A - Method for recovering paint in vehicle coating - Google Patents

Abstract

PURPOSE:To recycle a paint by recovering the paint supplied from a coating booth and floating in a separated water tank, removing water from the recovered paint, dissolving a cleaning solvent in the dehydrated paint to remove impurities and then adding a paint solvent to adjust viscosity. CONSTITUTION:An excess paint generated in a vehicle coating booth 1 is recovered as the coating paint. In this case, a paint P supplied to a separated water tank 6 from the lower tank 4 of the booth 1 along with water and floating on the water surface of a separated water tank 6 is recovered with a scoop net 9, etc., and the water is removed from the recovered paint P. A cleaning solvent used in cleaning a coating gun, etc., when colors are changed in coating is added to the dehydrated paint P which is dissolved. Impurities are removed from the dissolved paint, a paint solvent is added to the paint freed from the impurities to adjust viscosity to prepare a coating paint. The excess paint thus recovered is recycled, and resources are effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint recovery method for recovering excess paint generated in a paint booth in a vehicle painting process for reuse as paint for painting.

[0002]

2. Description of the Related Art Generally, when a vehicle body of a vehicle is spray-painted in a coating booth, the entire paint sprayed from the coating gun cannot be applied to the vehicle body, and a part of the paint adheres to the vehicle body. Do not use excess overspray paint. Then, normally, the mist-like overspray paint in the coating booth is captured by the wash water in the lower part of the paint booth and sent to the separation water tank together with the wash water, and floated as floating paint (sludge) on the water surface of the separation water tank. The floating paint is collected and incinerated.

In addition to the above, as a method of collecting the above-mentioned overspray paint, in the conventional method disclosed in Japanese Patent Application Laid-Open No. 2-218463, the paint is concentrated by heating and evaporating the wash water trapping the paint mist. Separated,
It is designed to incinerate this paint.

[0004]

However, in each of the above-mentioned conventional methods, although excess paint is recovered, it is incinerated, which is a great waste from the viewpoint of effective use of resources. In particular, when the coating efficiency is low, the amount of surplus paint increases, so the above waste cannot be ignored.

The present invention has been made in view of the above problems, and an object thereof is to reuse the recovered excess paint as a paint for coating by combining other materials generated in the vehicle painting process. The purpose is to enable effective use of resources.

[0006]

In order to achieve the above object, the present invention basically uses a cleaning solvent for cleaning a coating gun, etc., which is generated at the time of color change in a vehicle coating process. The solvent was added to the recovered excess paint to dissolve it, and the paint was reused as a paint for painting.

Specifically, according to the first aspect of the present invention, as a method of recovering the excess paint generated in the vehicle coating booth as the coating paint, it is supplied from the lower tank of the coating booth together with water to the separation water tank. The floating paint floating on the water surface of the separation water tank is collected, and water is removed from the collected paint. Then, to the drained paint, a cleaning solvent used for cleaning the coating gun and the like at the time of color change in the coating process is added and dissolved, and then impurities are removed from the dissolved paint, The feature is that a paint solvent is added to this paint to adjust the viscosity to make a paint for painting.

According to the second aspect of the invention, the paint recovered from the separation water tank is compressed by a compressor to remove water.

According to the third aspect of the invention, a cleaning solvent is added to the drained coating material, the mixture is left for a predetermined time, and then stirred to dissolve.

According to the fourth aspect of the invention, impurities are removed from the melted paint by a filter.

[0011]

With the above construction, in the first aspect of the invention, the surplus paint generated in the vehicle coating booth is supplied from the lower tank of the coating booth to the separated water tank together with water. Then, first, the floating paint floating on the water surface of the separation water tank is collected, and the water is removed from the collected paint. next,
A cleaning solvent used for cleaning the coating gun and the like at the time of color change in the coating process is added to the drained paint to dissolve it, and impurities are removed from the dissolved paint. Finally, a paint solvent is added to the paint from which the impurities have been removed to adjust the viscosity, whereby a paint for painting is made. The coating material thus obtained has impurities removed and its viscosity adjusted, so that it can be used without problems in coating.

Therefore, since the surplus paint that has been incinerated conventionally is reused as the paint for painting, it is possible to effectively use the resources. Moreover, the collected floating paint is dissolved by the cleaning solvent used for cleaning the coating gun when changing the color of the coating process.
The cleaning solvent that was normally disposed of can be reused, and the effective utilization of resources can be further improved.

According to the second aspect of the present invention, the paint recovered from the separated water tank is compressed by the compressor, whereby the water is removed from the paint. Therefore, it is possible to easily remove water from the recovered paint with a simple device.

According to the third aspect of the invention, the washing solvent is added to the drained paint, and the paint is left for a predetermined time and then stirred. Therefore, the paint after draining can be surely dissolved in the cleaning solvent.

According to the fourth aspect of the invention, impurities are removed from the melted paint by a filter. Therefore, it is possible to easily remove impurities from the paint after dissolution with a simple device.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows each step of a paint recovery method according to an embodiment of the present invention. The paint recovery method is a sequential recovery step A.
1, draining step A2, dissolving step A3, impurity removing step A
4 and the viscosity adjusting step A5.

As shown in FIG. 2, in the vehicle painting process,
In the spray booth 2 of the paint booth 1, paint is sprayed onto the car body from a paint gun (not shown) to paint the car body. A lower tank 4 is defined below the spray booth 2 through a partition floor 3 through which air can flow, and water is circulated and supplied to the lower tank 4, which is generated in the spray booth 2. Excessive mist-like overspray paint is discharged to the lower tank 4 through the partition floor 3 together with the exhaust gas, and is trapped in water in the lower tank 4. Further, a separation water tank 6 is connected to the lower tank 4 through an inclined waste liquid pipe 5, and the waste liquid 7 in which the overspray paint is captured in water is discharged to the separation water tank 6 through the waste liquid pipe 5, In the inside, the paint separates from the water 8 and becomes floating paint P (sludge) that floats on the water surface. Then, in the collecting step A1, the floating paint P floating on the water surface of the separation water tank 6 is scooped up by a scooping net 9 or the like and collected.

In the next draining step A2, the collecting step A is performed.
The floating paint P collected in 1 is put into the compressor 12 shown in FIG. 3 to remove water from the paint P. That is, the compressor 12 has a bottom 14a made of a wire mesh which is located at a predetermined height from the floor by the legs 13, 13, ... A pressing plate 15 which is arranged so as to be able to move up and down so as to close and close the opening of the box 14 inside, and a pressing plate 15 which is arranged so as to extend in the vertical direction and is fixedly supported on the upper part of the storage box 14,
a pressure cylinder 16 whose lower end is connected to the pressing plate 15
And Then, with the opening of the storage box 14 in the compressor 12 opened, the recovery step A
After the floating paint P collected in 1 is closed and the opening of the box 14 is closed by the pressing plate 15, the pressing plate 15 is lowered by the extension operation of the pressure cylinder 16 to move the floating paint P to the bottom 14a of the box 14. By pressing it against, the paint P is compressed and squeezed between the pressing plate 15 and the bottom portion 14a to remove water from the paint P. Reference numeral 17 is water dropped from the box bottom portion 14a.

At this time, the recovered paint P is compressed by the compressor 12
Since the water content is removed from the coating material P by compressing with, the water content of the coating material P can be easily removed.

The coating material P drained in this way is dissolved in the dissolution step A3. In this melting step A3, first, as shown in FIG. 4, after the paint P is stored in the melting tank 19,
A waste thinner 20 is put into the dissolution tank 19 as a solvent (cleaning solvent) from a thinner can 21. That is, in the above vehicle painting process, although not shown, in order to wash away the paint of the color up to that point from the paint flow path from the color change valve to the painting gun with a color change that changes the paint color of the vehicle body, After the gun is positioned in the designated thinner recovery box in the painting booth 1, the thinner is sprayed into this thinner recovery box in the same manner as the paint, and the thinner sprayed into the thinner recovery box is collected in the thinner recovery tank. Will be stored. Then, the waste thinner 20 used for cleaning the painting gun and the like at the time of such color change is used as the solvent, and the dissolution tank 1 is used.
Throw in 9.

Then, after leaving the waste thinner 20 for a predetermined time (for example, 24 hours), the paint P in the dissolution tank 19 is stirred by a stirrer 23 as shown in FIG.
And the thinner 20 are stirred to dissolve the paint P.

As described above, since the waste thinner 20 is added to the paint P and left for a predetermined time and then stirred by the stirrer 23, the paint P can be surely dissolved by the thinner 20.

Next is an impurity removing step A4, in which impurities are removed from the coating material P dissolved in the dissolving step A3. In this step, as shown in FIG. 6, the viscosity P of the paint P in the dissolution tank 19 is sucked by the pressure pump 25 to adjust the viscosity of the viscosity adjustment tank 27.
Pump to. Then, at this time, a filter 28 having a predetermined mesh (for example, 10 mesh) is arranged between the dissolution tank 19 and the pump 25, and the filter 28 causes an aluminum piece or mica for metallic paint mixed in the dissolution paint. Impurities such as pieces (mica) are filtered and collected, and only the paint P having no impurities is supplied to the viscosity adjusting tank 27.

Since impurities are removed from the paint P in this way, even if impurities such as aluminum flakes are included in the paint of the metallic coating performed in the painting process, those impurities are removed.

Since the filter 28 removes impurities, the impurities can be easily removed.

Finally, in the viscosity adjusting step A5, as shown in FIG. 7, a paint thinner 30 as a new paint solvent is added to the paint P obtained in the impurity removing step A4 in the viscosity adjusting tank 27 as a thinner can. The viscosity of the coating material P is adjusted by adding from 31. The paint P whose viscosity is adjusted as described above is used as a paint for spray coating.

Therefore, in this embodiment, the floating paint which has been incinerated conventionally can be collected and reused as the paint P for painting. Moreover, since the collected paint P is dissolved by the waste thinner 20 used for cleaning the coating gun and the like during the color change in the painting process, the waste thinner 20 can be reused. Therefore, effective use of resources can be achieved.

Further, the paint P for coating thus obtained can be used without trouble because the impurities such as aluminum pieces contained in the original paint are removed and the viscosity thereof is adjusted. .

Since the floating paint P contains various colors used for vehicle body painting, the paint P obtained by dissolving the floating paint P with the waste thinner 20 has a blackish gray color (charcoal gray). become. Therefore, the coating material P can be used favorably as an undercoating material for a vehicle body, and if a new black coating material is added, it can also be used as an overcoating material for a black portion such as a vehicle body floor or a fuel tank.

[0030]

As described above, according to the invention of claim 1, the floating paint which is supplied together with water from the lower tank of the vehicle coating booth and floats in the separation water tank is recovered to remove water, To this drained paint, add the cleaning solvent used for cleaning the coating gun etc. at the time of color change in the coating process to dissolve it, then remove impurities from the paint, and then add the coating solvent By adjusting the viscosity of the paint and using this paint as the paint for painting, the excess paint that had been incinerated in the past can be reused as the paint for painting, and the collected floating paint can be used for color changes during the painting process. The cleaning solvent can be dissolved and reused, and thus effective use of resources can be achieved.

According to the second aspect of the present invention, the floating paint recovered from the separated water tank is compressed by the compressor to remove the water content, whereby an apparatus for removing the water content from the recovered paint can be easily obtained. It is possible to facilitate removal of water.

According to the third aspect of the present invention, by adding a cleaning solvent to the drained coating material, allowing it to stand for a predetermined time, and then stirring and dissolving it, the solubility of the coating material after draining in the cleaning solvent can be improved. it can.

According to the fourth aspect of the present invention, by using the filter when removing the impurities, an apparatus for removing the impurities from the paint after melting can be easily obtained, and the removal of the impurities can be facilitated. be able to.

[Brief description of drawings]

FIG. 1 is a process drawing showing each process in an example of the present invention.

FIG. 2 is a diagram schematically showing a paint collecting process.

FIG. 3 is a diagram schematically showing a draining step.

FIG. 4 is a diagram schematically showing a state in which waste thinner is added in a melting step.

FIG. 5 is a diagram schematically showing a stirring state in a dissolving step.

FIG. 6 is a diagram schematically showing an impurity removing step.

FIG. 7 is a diagram schematically showing a viscosity adjusting step.

[Explanation of symbols]

 A1 Recovery process A2 Draining process A3 Dissolution process A4 Impurity removal process A5 Viscosity adjustment process P Paint 1 Coating booth 4 Lower tank 6 Separation water tank 12 Compressor 20 Waste thinner (washing solvent) 28 Filter 30 Paint thinner (paint solvent)

Claims (4)

[Claims] 1. A method for recovering excess paint generated in a vehicle coating booth as coating paint, which is supplied from a lower tank of the coating booth together with water to a separation water tank and floats on the water surface of the separation water tank. Floating paint that has been collected is removed, water is removed from the collected paint, and the cleaning solvent used to clean the coating gun etc. at the time of color change in the painting process is added to the drained paint. A method for recovering paint in vehicle painting, which comprises dissolving and removing impurities from the dissolved paint, and then adding a paint solvent to the paint from which impurities are removed to adjust the viscosity to prepare a paint for painting. 2. The paint recovery method for vehicle painting according to claim 1, wherein the paint recovered from the separated water tank is compressed by a compressor to remove water. 3. The method for recovering paint in vehicle painting according to claim 1, wherein a washing solvent is added to the drained paint, left for a predetermined time, and then stirred to dissolve. . 4. The paint recovery method for vehicle painting according to claim 1, wherein impurities are removed from the dissolved paint by a filter.