METHOD FOR CONTROLLING OPENING AND CLOSING SPEED OF VALVE MECHANISM OF DISCHARGE GUN, APPARATUS THEREFOR, AND DISCHARGE COATING METHOD FOR LIQUID BODY

PROBLEM TO BE SOLVED: To provide such a coating method which prevents the expansion of a coating line width by a rapid increase in a coating weight at the end point of coating prevents the generation of air bubbles near the start point of coating and further maintains the specified coating line width even if the relative moving speed of a discharge gun and a substrate is variably controlled in the method for discharging and applying a liquid body to a linear shape on a substrate surface by using a discharge coating applicator of the liquid body constituted to relatively move the discharge gun having a valve mechanism and the base material. SOLUTION: The technique of discharging and applying the liquid material to the substrate surface from the nozzle 10 of the discharge gun 1 by using the discharge gun 1 having the valve mechanism is so constituted that the opening and closing action of the valve mechanism of the discharge gun 1 is executed by a reduced pressure actuator. A liquid pressure supply circuit for supplying the liquid pressure to the reduced pressure actuator is provided with a flow rate control means. The opening and closing speed of the valve mechanism of the discharge gun 1 is controlled by adjusting the flow rate control means. In addition, the coating is executed while the opening degree of the valve mechanism is adjusted by controlling the liquid pressure supply rate to the reduced pressure actuator in proportion to the relative moving speed of the discharge gun 1 and the substrate 6.