PURPOSE: To permit bubbles in a coating liquid to be dissolved and disappear into a liquid efficiently and rapidly and thereby eliminate a functional failure due to the bubble during the application by causing the liquid containing bubbles to pass through a circulation container comprising a narrow gap and emitting an ultrasonic wave to the liquid.
CONSTITUTION: A coating liquid is sent to a defoaming step from a coating liquid preparation device 4 by a pump 5. An ultrasonic emission device 2 is arranged below a defoaming device 1, and both defoaming device 1 and ultrasonic emission device 2 are installed in a thermostatic device 3. The thermostatic device 3 is filled with water and maintained at a certain temperature level. The coating liquid enters from an inlet-side pipe 8, flowing through a circulation passage 13 between a sleeve 11 and an inner pipe 12, and comes out of an outlet-side pipe 9 under ultrasonic irradiation. The coating liquid coming out of an ultrasonic defoaming step receives a hydraulic value measurement by a manometer 6 and the flow of the coating liquid is controlled by controlling the pump 5 based on the measurement data. Finally, the coating liquid is sent to a following step after checking the pressure of absevie of a bubble using a bubble detector 7.
ICHIKAWA KAZUYOSHI
SUZUKI SHINICHI
