JP4402388B2 - Cleaning method for two-component mixing controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning method for a two-component mixing control device that supplies a main agent and a curing agent, such as those used in two-component polyurethane coatings, with accurate metering and mixing control.
[0002]
[Prior art]
In recent years, various fields are required to respond to environmental pollution problems, and urgent improvements are also required in paints and coating methods. Two-component polyurethane coating and two-component epoxy coating are one of the countermeasures. Elongating paint and painting method. In two-component polyurethane coating and two-component epoxy coating, a curing agent, which is a catalyst, is mixed and sprayed on the main component with few solvent components, and a coating is formed by reaction curing. This is a coating method that can reduce the energy consumption by eliminating the need for a drying furnace and lowering the temperature. Furthermore, the production volume is increasing due to excellent coating performance such as weather resistance, chemical resistance and water resistance.
[0003]
However, in two-component paints such as two-component polyurethane paints and two-component epoxy paints, there is a limit on the usable time called the usable time when a curing agent is mixed with the main agent. If it passes, it will be hardened in the painting equipment, so it is necessary to perform the painting work within the pot life. In addition, if left untreated, the inside of the flow path of the apparatus will be hardened and fixed, and the inside of the flow path will become clogged. There is a need. In addition, it is necessary to periodically clean the apparatus for reasons of color change, and the cleaning work in the painting work is regarded as fatal and important.
[0004]
In order to sufficiently clean the coating apparatus after use, as for the conventional cleaning method, as described in JP-A-2000-189863, the cleaning liquid is continuously supplied and air is intermittently mixed in the cleaning liquid. Thus, there is a technique for enhancing the cleaning effect in the flow path by utilizing turbulent flow by so-called gas-liquid mixing, such as alternately supplying the cleaning fluid in an atomized state and supplying only the cleaning liquid several times. It can be seen. Although the technique described in the above publication relates to a cleaning method at the time of color change, it is also used as a cleaning method for a two-component mixing control device as a method for efficiently cleaning the inside of a flow path.
[0005]
Japanese Patent Application Laid-Open No. 7-178356 describes the specific technical contents of the switching means and the timer means for defining the switching timing when alternately supplying the cleaning agent and the pressurized air as in the above publication. ing. Cleaning solvents used for these are mainly organic solvents such as thinner. In the case of solvent-based two-component paints, the main agent is washed with a cleaning agent dedicated to the main agent, but the main agent is washed with an organic solvent for curing agent cleaning. However, there was no problem of hardening and fixing on the inner wall of the flow path of the apparatus.
[0006]
In recent years, paints are becoming water-based as environmental pollution countermeasures. When two-part curable water-based paints are used in two-part mixing control devices, when the equipment is washed, it is good that the curing agent and water react and cure. It is common knowledge that it is common sense that workers perform cleaning work while paying attention to this point, but recently, water-based paints are also applied from architectural top coating to general metal parts, car interior resin parts, etc. Since applications such as painting have been expanded and widely used, there are a wide variety of types, and some paints react strongly and harden when the main agent and (organic) solvent for cleaning the hardener are mixed.
[0007]
For example, in Japanese Patent Application Laid-Open No. 10-230234, when a hydro-soft feel lacquer is used in a composite component mixing system, the base resin and the solvent provided on the catalyst side have no affinity, so both are mixed. There is disclosed a cleaning method at the time of color change, in which water and air are alternately and intermittently injected into the mixing chamber to completely purge the mixed material and then flow the catalyst solvent.
[0008]
However, when the two-component curable water-based paint that reacts and hardens when the main agent and (organic) solvent for cleaning the curing agent are mixed is used in the two-component mixing controller, the solvent-based two-component curable type Unlike paints, there is currently no cleaning solution that can be used for both the main agent and curing agent, and the main agent must be washed with water, and if it is not cleaned with a solvent-based cleaning solution, it will harden and adhere to the inner walls of the flow path. It was. In addition, washing using water and air-liquid turbulent flow alone is not sufficient for washing water-based paints that are generally difficult to dissolve. Forcing the worker to perform such a complicated cleaning work and relying on the level of proficiency of the worker has hindered reliable cleaning work.
[0009]
[Problems to be solved by the invention]
In view of the above-mentioned problems, the present invention ensures that the inside of the flow path of the two-component mixing control device is not hardened or fixed or burdens the operator depending on the type of aqueous paint used. An object is to provide an economical and quick cleaning method.
[0010]
[Means for Solving the Problems]
In the present invention, each liquid is supplied to the mixing chamber through an individual flow path so that the two liquids of the main component and the curing agent of the two-component curable water-based paint are mixed at a constant mixing ratio, and mixed in the mixing chamber. In the cleaning method of the two-component mixing control device for supplying the coating device to the coating device, after the mixed solution remaining in the mixing chamber and downstream of the mixing chamber is discharged out of the two-component mixing control device by compressed air, The flow path downstream of the mixing chamber is cleaned with the aqueous main agent cleaning liquid, then the curing agent solvent cleaning liquid and the compressed air supply are alternately repeated for cleaning, and finally the aqueous main agent cleaning liquid is added to the mixing chamber and the mixing chamber. The cleaning step is completed by filling the flow path downstream of the chamber. When a solvent-based cleaning solution for aqueous base and curing agent were used paint curing reaction according to this cleaning method, not only almost no chance to contact with solvent-based cleaning solution for aqueous base and curing agent, its even in contact Since the amount is small and discharged outside the apparatus before being cured, it can be said that this is an effective cleaning method that does not cure and fix the mixed solution in the apparatus flow path. That is, the mixed liquid is first discharged with compressed air and then washed with the aqueous main agent cleaning liquid. At this stage, the aqueous main agent is generally discharged out of the apparatus. Then typically a strong detergency curing agent for solvent-based cleaning fluid by turbulence almost completely washed performs flow path cleaning of utilizing, and finally is filled with an aqueous base-agent cleaning liquid in the flow path, the flow It is possible to prevent the liquid mixture from drying and hardening at a stagnant part such as a joint of a road.
[0011]
Further, the present invention provides a two-component mixing control in which two types of liquids are supplied to a mixing chamber through individual channels so that two types of liquids are mixed at a constant mixing ratio, and the mixed liquid mixed in the mixing chamber is supplied to a coating apparatus. In the cleaning method of the apparatus, a cleaning step of cleaning and filling the aqueous main agent supply flow path up to the front of the mixing chamber with an aqueous main agent cleaning liquid, and a curing agent supply flow path up to the front of the mixing chamber with a solvent-based cleaning liquid for the hardener. A washing step of filling after washing, and after the mixed liquid remaining in the mixing chamber and downstream of the mixing chamber is discharged out of the two-component mixing control device by compressed air, the flow path downstream of the mixing chamber and the mixing chamber is aqueous Washing with the main agent cleaning liquid, and then cleaning by repeatedly supplying the solvent-based cleaning liquid for the hardener and the compressed air, and finally filling the flow path downstream of the mixing chamber with the aqueous main agent cleaning liquid. In parallel with the cleaning process It is to perform. As a result, the cleaning time can be shortened. Therefore, in the case of a paint having a short usable time, the operator is not forced to perform complicated work in a short time, and work errors can be prevented.
[0012]
In addition, since the present invention is a cleaning method for a two-component mixing control device in which the cleaning of each supply channel is controlled based on an automatic cleaning program, several automatic cleaning programs by a microcomputer are assembled and stored. By arbitrarily selecting and executing the program according to the coating conditions such as the properties of the paint and the pipe length, the cleaning time and valve switching timing can be adjusted, so it is reliable, economical and quick. Cleaning is possible.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a supply liquid path diagram of a two-liquid mixing control apparatus showing an embodiment of the cleaning method of the present invention. Referring to this figure, the aqueous main agent is supplied from the aqueous main agent supply device 2, and after being measured by the flow meter 4 through the switching valve 3, is sent to the mixing chamber 11 by the control of the on-off valve 5. On the other hand, the curing agent is supplied from the curing agent supply device 16, and is sent to the mixing chamber 11 by controlling the on-off valve 13 after measuring the flow rate by the flow meter 14 through the switching valve 15. Both liquids supplied at a constant rate are mixed in the mixing chamber 11 and guided to the spray gun 10 to start the painting operation.
[0014]
When the painting operation is completed, each flow path is cleaned. The cleaning of the aqueous main agent supply flow path up to the front of the mixing chamber 11 is performed as follows. It is supplied the main agent for the cleaning liquid supply device 1 from the aqueous base-agent wash flow aqueous base-agent washings in a state where the supply of aqueous base resin was stopped by the switching valve 3. The on-off valve 5 is closed, the drain valve 6 is opened, and the aqueous main agent is discharged out of the two-component mixing control device. After the aqueous main agent is sufficiently washed away from the inside of the flow path, the aqueous main agent cleaning liquid is filled in the flow path to prevent dry hardening and fixing of the aqueous main ingredient .
[0015]
The curing agent cleaning of the supply channel until the front of the mixing chamber 11 as well as aqueous base resin, solvent-based cleaning liquid curing agent is supplied from the curing agent for the cleaning liquid supplying device 17, the supply of the hardener by the switching valve 15 is stopped In such a state, the solvent-based cleaning liquid for the curing agent is poured. The on-off valve 13 is closed, the drain valve 18 is opened, and the curing agent is discharged out of the two-component mixing controller. After the curing agent is sufficiently washed away from the inside of the channel, a solvent-based cleaning liquid for curing agent is filled in the channel to prevent the curing agent from being dried and cured and fixed.
[0016]
To clean the flow path in the mixing chamber 11 and downstream of the mixing chamber, first, the compressed air that has passed through the switching valve 8 and the on-off valve 7 is sent to the mixing chamber 11, and the mixed liquid is mixed into the two liquids from the drain valve 9 or the spray gun 10. Drain out of control unit. Needless to say, the on-off valves 5, 12, and 13 are closed at this time. Next, an aqueous main agent cleaning liquid is supplied from the main agent cleaning liquid supply device 1 via the switching valve 8 and enters the mixing chamber 11. The mixed liquid is diluted with the aqueous main agent cleaning liquid from the drain valve 9 or the spray gun 10. It is discharged out of the liquid mixing controller.
[0017]
Then curing agent for solvent-based cleaning liquid supplied from the curing agent for the cleaning liquid supply device 17 and the compressed air is alternately repeated by each of the on-off valve 7 and 12 open and close operations (e.g. alternately opened and closed by 2-3 seconds) The mixed liquid which is supplied to the flow path in the mixing chamber 11 and downstream of the mixing chamber and slightly remains in the flow path is so-called flushed and cleaned by the solvent-based cleaning liquid for the curing agent and the compressed air, and is supplied from the drain valve 9 or the spray gun 10. It is discharged out of the liquid mixing controller. Finally, the aqueous main agent cleaning liquid is filled from the main agent cleaning liquid supply device 1 into the mixing chamber 11 and the flow path downstream of the mixing chamber via the switching valve 8 and the on-off valve 7 to complete the cleaning process.
[0018]
For these cleaning operations, several automatic cleaning programs using a microcomputer can be set up, and if they are stored, it is possible to automatically adjust the cleaning time, valve switching timing, etc., by selecting one of the operator's buttons. In addition, the flow paths before and after the mixing chamber 11 can be simultaneously and independently cleaned to complete the entire cleaning process in 1 to 2 minutes. Of course, it is possible to arbitrarily extend the cleaning time, for example, when cleaning difficult-to-dissolve paint or when the pipe length is long.
[0019]
【The invention's effect】
As described above, according to the cleaning method of the present invention, when a paint in which the aqueous main agent and the solvent-based cleaning liquid for the curing agent react and harden, for example, an aqueous two-component paint is used in a two-component mixing control device, The inside of the flow path is not cured or fixed. In addition, it is possible to perform cleaning of each of the aqueous main agent supply channel, the hardener supply channel, the mixing chamber and the downstream of the mixing chamber up to the front of the mixing chamber individually and in parallel by setting up an automatic cleaning program. Can be shortened and reliable cleaning can be achieved without forcing the operator to perform complicated operations. Furthermore, generally, the solvent-based cleaning liquid for the curing agent , which is a solvent system, is flushed to reduce the solvent discharge.
[Brief description of the drawings]
FIG. 1 is a supply liquid path diagram of a two-liquid mixing control apparatus showing an embodiment of a cleaning method of the present invention.
[Explanation of symbols]
1 main agent for the cleaning liquid supply device 2 aqueous base compound feeder 3,8,15 switching valve 4,14 flowmeter 5,7,12,13-off valves 6,9,18 drain valve 10 the spray gun 11 mixing chamber 16 curing agent feeder 17 Hardener cleaning liquid supply device

Claims (2)

Two liquids that supply each liquid to the mixing chamber through an individual flow path and mix the mixed liquid in the mixing chamber to the coating device so that the main component of the two-component curable water-based paint and the curing agent are mixed at a constant mixing ratio. in the cleaning method of the mixing control device, and a cleaning step of the aqueous base material supply channel up to the mixing chamber before filling washed with a washing solution for aqueous base resin, solvent-based hardener for the curing agent supply passage until said mixing chamber before A cleaning step of filling after cleaning with a cleaning liquid, and a flow path in the mixing chamber and in the downstream of the mixing chamber after the mixed liquid remaining in the mixing chamber and in the downstream of the mixing chamber is discharged out of the two-component mixing controller by compressed air Is washed with an aqueous main agent cleaning liquid, and then the solvent-based cleaning liquid for curing agent and compressed air are alternately supplied repeatedly for cleaning. Finally, the aqueous main agent cleaning liquid is passed through the flow path in the mixing chamber and downstream of the mixing chamber. washing step of filling the can Cleaning method of a two-liquid mixing control apparatus characterized by be performed separately and concurrently. The cleaning method for a two-component mixing control apparatus according to claim 1, wherein cleaning of each supply channel is controlled based on an automatic cleaning program.

Images