JP2002066410A - Recycle system for aqueous coating material and foreign- matter removal method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycle system which can stably recover a regenerated coating material while preventing the degradation of external appearance of a coating film obtained from the regenerated coating material. SOLUTION: In this recycle system for an aqueous coating material, an object is spray coated with an aqueous coating material with a spray gun in a water-curtain type coating booth; an over-spray part of the coating material, which does not adhere to the object, is covered with a water curtain and is sent as a collection liquid from a booth circulation water vessel to a concentration vessel; the liquid is separated into a concentrated coating material and a filtrate with an ultrafiltration apparatus; the concentrated coating material is further concentrated and then adjusted to give a regenerated coating material; and the regenerated coating material is again spray applied. In the system, a filter for removing foreign matters is installed in the inside of equipment or apparatuses arranged in the range from the recovery of an aqueous coating material to the spray coating with the regenerated coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for spray-coating an aqueous paint, recovering, separating and concentrating the paint, and then preparing the reclaimed paint obtained by adjusting it. The present invention relates to a method for removing dust and foreign matter generated from paint components.

[0002]

2. Description of the Related Art Water-based paints have been frequently used for painting industrial products. Water-based paints can be used as paint after collecting paint (overspray paint) that has not adhered to the object at the time of painting with water, filtering and concentrating it, and using it again as paint. It is particularly noted because it can be reused. In addition, since the filtrate is water, it has advantages such as easy handling and no problem such as air pollution when an organic solvent is used.

In a water-based paint recycling system, generally, as shown in FIG. 1, a water-based paint 20 is spray-coated on a workpiece 50 from a coating gun 2 in a water-curtain type painting booth 1, and is applied to the workpiece 50. Water curtain containing unsprayed overspray paint 4 containing booth circulating water 6
Collected by 3. The recovered paint is sent from a booth circulating water tank 5 to a concentration tank 7 as a collection liquid 8. If necessary, the collected liquid 8 is passed through an ultrafiltration device 9 to separate the filtrate 11, and further concentrated several times through the ultrafiltration device 9 to concentrate the obtained concentrated paint 13 into a concentrated paint tank 12. Transfer and store. After adjusting the composition of the concentrated paint 13 stored in the concentrated paint tank 12 to obtain a reclaimed paint 21, the reclaimed paint 21 is subjected to spray painting again in the water curtain type painting booth 1 as an aqueous paint 20.

However, when a recycled paint is prepared by using such a recycling system, a water-based paint is applied in the recycling system, and after the collection is completed, the dried paint solidified due to insufficient washing inside the system. Paint components, dust and foreign matter other than paint components (for example, water-insoluble components such as suspended matter in the air, and oil components such as machine oil) may be present in the coating booths, tanks, devices, or tanks and devices in the system. Garbage or foreign matter generated from the environment or humans (for example, suspended solids in the air) when remaining in the pipes connecting equipment or equipment, or when the adjusted reclaimed paint is taken out and transferred to another container outside the recycling system , Fibers, human sebum, etc.) in the container, dust and foreign matter may be mixed in the recycled paint.

[0005] For example, the recycling system used in the conventional method described in Japanese Patent Application Laid-Open No. 5-228422 and the like, as shown in FIG. 1, eliminates the clogging of the ultrafiltration device 9 due to the presence of dust and foreign matter. To prevent this, a pre-filter 30 for removing dust and foreign matters is provided from the concentration tank 7 to the ultrafiltration device 9.

[0006] However, the pre-filter 30 used in the conventional method including the above-mentioned publication is intended only to prevent clogging of the ultrafiltration device 9. Therefore, when the overspray paint is collected and reused, if there is a foreign substance, for example, a water-insoluble component or an oily component (including, for example, machine oil) in the recycling system, the collected reclaimed paint is used. In some cases, cissing or dents occurred in the resulting coating film, or poor appearance was caused.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recycling system and a method using the same, which can prevent the appearance of a coating film obtained from the recycled paint from being deteriorated and can stably recover the recycled paint. It is.

[0008]

That is, the present invention relates to an overspray paint which is obtained by spray-coating an aqueous paint on an object to be coated by using a coating gun in a water curtain type coating booth, and not applying to the object. Is collected by a water curtain, sent from a booth circulating water tank to a concentration tank as a collected liquid, the collected liquid is separated into a concentrated paint and a filtrate by an ultrafiltration device, and the concentrated paint is further concentrated and adjusted. In the water-based paint recycling system for making the reclaimed paint by this and then applying the reclaimed paint to the spray coating again, in the equipment or apparatus disposed between the recovery of the water-based paint and the repainting of the regenerated paint again. The present invention relates to a water-based paint recycling system, provided with a filter for removing foreign matter. Further, the present invention also provides a method for removing foreign substances by the aqueous paint recycling system.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention is to provide a foreign matter removing filter in a water-based paint recycling system in a facility or an apparatus arranged between recovery and reuse of recycled paint. For example, in the water-based paint recycling system shown in FIG. 1, a paint tank 14 for storing the regenerated paint 21 from the concentrate tank 7 to the space between the booth circulating water tank 5 and the concentrate tank 7, from the concentrate tank 7 to the ultrafiltration device 9. And at least one of the insides of equipment or devices such as tanks and pipes (for example, the coating gun 2) until the recycled paint is reused as a water-based paint from the paint tank 14.
A foreign substance removing filter can be installed at the location. In particular, since adjustment of the reclaimed paint for reuse is usually performed in the paint tank 14 or between the paint tank 14 and the paint gun 2, a filter is installed between the paint tank 14 and the paint gun 2. Is preferred.

The foreign matter removing filter preferably used in the present invention has a physical filtering action such as a wire mesh defined by the number of meshes according to the type and size of the dust or foreign matter to be removed. Alternatively, it may have a chemical adsorption action. Examples of such a filter having a chemical adsorption action include an oil magnet filter for removing water-insoluble components and oil-based components.

The foreign matter removing filter used in the present invention includes various equipments and devices in a conventionally used aqueous paint recycling system (for example, a water curtain type painting booth 1, a booth circulating water tank 5, a concentration tank 7, a filtration tank 10). , Each tank such as the concentrated paint tank 12, and each device such as the coating gun 2 and the ultrafiltration device 9 and the piping connecting them).

In the present invention, a pre-filter for preventing clogging of an ultrafiltration device, which has been conventionally used, may be used together with the foreign matter removing filter. Prefilters are useful for removing dirt or foreign matter that is larger than the filtration performance of the ultrafiltration device. By this foreign matter removing filter, it is possible to stably supply a recycled paint that does not contain unnecessary foreign matter.

[0013] The foreign matter removing filter is particularly preferably
A pipe for feeding the reclaimed paint 21 to the painting gun 2 or the inside of the painting gun 2 is installed. By doing so, even if foreign matter is present during storage of the reclaimed paint, it can be removed at the time of spray coating, and the quality of the obtained coating film can be further improved.

When the foreign matter removing filter is installed inside a facility for storing the regenerated paint before and after the composition adjustment in order to prevent the reclaimed paint from solidifying, it is necessary to install a filter having a chemical adsorption function. More preferred.

The inside of the equipment for storing the reclaimed paint before and after the composition adjustment is, specifically, the concentration tank 7, the paint tank 1
4, and the interior of the piping and the equipment (eg, paint gun 2) located between the paint tank 14 and the reuse of the reclaimed paint as a water-based paint, and most preferably has a physical filtration action. And a filter having a chemical adsorption effect.

[0016]

According to the present invention, in a water-based paint recycling system, paint components which are scattered during coating and adhere to a coating booth or the like and are dried and solidified, or dust or foreign matter other than the paint components (for example, in the air) (A non-water-soluble component such as a suspended solid or an oil component such as a machine oil) can be obtained as a reclaimed paint free of such foreign substances. Further, according to the present invention, when the recycled paint after the composition adjustment is taken out of the recycling system and transferred to another container, dust or foreign matter (for example, suspended matter in air, fiber, or human sebum) generated from the environment or humans. , Etc.) can be removed even when these materials are mixed in the recycled paint. That is, by applying the method of the present invention, it is possible to stably supply a reclaimed paint containing no foreign matter, and to improve the quality of a coating film obtained from the reclaimed paint. Usability may be further improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a water-based paint recycling system.

[Explanation of symbols]

1 ... paint booth, 2 ... paint gun, 3 ... water curtain, 4 ... overspray paint, 5 ... booth circulating water tank, 6
... Booth circulating water, 7 ... Collecting liquid, 8 ... Concentration tank, 9 ... Ultrafiltration device, 10 ... Filtration tank, 11 ... Filtrate, 12 ... Concentrated paint tank, 13 ... Concentrated paint, 14 ... Recycled paint is stored. Equipment, 20: water-based paint, 21: reclaimed paint, 30: pre-filter, 50: substrate.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takahito Otsu 19-17 Ikedanakacho, Neyagawa-shi, Osaka F-term in Nippon Paint Co., Ltd. (Reference) 4D006 GA06 KA01 KB12 KB14 KB30 PA04 PB20 PC80 4D032 AC09 DA04 4D073 AA10 DD40

Claims (5)

[Claims] 1. A water-based paint is spray-coated on an object to be coated in a water-curtain type coating booth using a coating gun, and overspray paint not applied to the object is collected by a water curtain. To the concentration tank as a collected liquid, the collected liquid is separated into a concentrated paint and a filtrate by an ultrafiltration device, and the concentrated paint is further concentrated and adjusted to obtain a reclaimed paint. In a water-based paint recycling system to be subjected to spray coating again, a filter for removing foreign matter is provided inside equipment or a device arranged between the recovery of the water-based paint and the spray coating of the regenerated paint again. A water-based paint recycling system, characterized in that: 2. A method for removing foreign matter using the aqueous paint recycling system according to claim 1. 3. Between the booth circulating water tank and the concentration tank disposed in the recycling system, between the concentration tank and the ultrafiltration device, and between the tank and the paint tank for storing the regenerated paint taken out of the concentration tank. Equipment including each tank and piping until the reclaimed paint is taken out from the paint tank and transferred to another container arranged outside the recycling system, and until the reclaimed paint in the recycling system is spray-coated. 3. The method according to claim 2, wherein a foreign matter removing filter is installed at at least one position inside the apparatus. 4. The foreign matter of the recycled paint in the water-based paint recycling system according to claim 2, wherein a filter having a chemical adsorption action is installed inside the paint tank that stores the recycled paint inside or outside the recycling system. Removal method. 5. The method according to claim 2, wherein a foreign matter removing filter is installed inside the coating gun in the recycling system.