To provide a coating device capable of stably discharging a coating liquid for a long period.
The coating device for applying the coating liquid prepared by dispersing MgO powder in a solvent by a spray method in a process for forming a crystalline MgO layer of a plasma display panel is provided with a first three-way valve 600 through which a connection pipe 531 for connecting to a coating liquid flow passage is connected to a discharge pipe 513A and a cleaning pipe 522 so as to switch respective connection states, and a second three-way valve 700 through which the connection pipe 531 is connected to a return pipe 514 and the cleaning pipe 522 so as to switch respective connection states. A cleaning liquid is caused to flow into the first three-way valve 600 so as to be discharged by a spray gun from the discharge pipe 513A, and the cleaning liquid is caused to flow into the second three-way valve 700 to allow to pass through the first three-way valve from the connection pipe 531 so as to be discharged from the discharge pipe 513A by the spray gun. The sticking of the MgO powder or the clogging due to the MgO powder is not caused and the coating liquid can be applied over a long period.
Kanji Nakayama
Tsuyoshi Ishizaki
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