JPS6025193B2 - Curtain flow coater with membrane breakage detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curtain flow coater equipped with a film breakage detection device that automatically detects film breakage in a paint liquid film of a curtain flow coater used to apply paint to a plate-shaped body. A photoelectric detection device A consisting of a light emitter 3 and a light receiver 4 that reciprocates with respect to the middle direction of the paint liquid film 5 flowing out from the slit 2 of the curtain flow coater 1 is provided. The present invention relates to a curtain flow coater equipped with a film breakage detection device, which is characterized in that the film breakage detection device is arranged diagonally.

As shown in FIG. 1, the paint liquid film 5 is flowed out from the slit 2 of the curtain flow coater 1 through the middle L and slit Chuichi, and the paint is applied to the surface of the plate-like body 6 by passing through the plate-like body 6 underneath. When doing this, if the slit is made extremely narrow, foreign objects in the paint may get caught, or for other reasons, a break 7 as shown in Figure 2 is likely to occur, making monitoring and adjustment troublesome. Therefore, there was a problem in that coating defects occurred when the film broke.

For this reason, there is a drawback in that a skilled worker must be assigned to monitor and adjust the curtain flow coater 1 to prevent coating defects. The present invention was invented in view of the above points, and its purpose is to eliminate the problem of film breakage of the paint liquid film flowing out from the curtain flow coater without requiring skilled workers as in the past. To provide a curtain flow coater equipped with a film breakage detection device that can immediately detect film breakage when the film is broken, and can reliably detect film breakage in any part of the paint liquid film by reciprocating a projector and a light receiver. be. The present invention will be explained in detail below with reference to Examples.

A light emitter 3 that reciprocates left and right is placed on either the front or rear side below the slit 2 of the curtain flow coater 1, and a receiver 4 that reciprocates left and right is placed on the other side. A photoelectric detection device A with a light receiver 4
is formed. Here, the photoelectric detection device A, which is a set of a projector 3 and a receiver 4, is arranged obliquely with respect to the paint liquid film 5, as shown in FIG. In this state, the light emitter 3 and the light receiver 4 reciprocate to scan the middle L of the paint liquid film 5. Now the 4th
As shown in Figure a, when there is no break in the paint liquid film 5, a part of the light emitted from the projector 3 Po is reflected by the paint liquid film 5, and the transmitted light is also slightly refracted and diffused. The amount of light Pi received by the light receiver 4 satisfies Pi<Po. However, as shown in FIG. 4b, when a film breakage 7 occurs in the paint liquid film 5, the amount of light emitted by the light emitter 3 Po becomes equal to the amount of light received by the light receiver 4 Pi, and Po=Pi. By detecting changes in the amount of light received in this way, film breaks 7 in the curtain flow coater 1 are automatically detected, and when film breaks 7 occur, the conveyance of the plate-shaped body 6 is immediately stopped and the operator is notified by a signal. It looks like this. Note that the film breakage 7 of the paint liquid film 5 may be detected based on the presence or absence of reflected light when a portion of the light emitted by the light receiver 3 is reflected by the paint liquid film 5. Thus, in the present invention, since a photoelectric detection device consisting of a light emitter and a light receiver is provided which moves back and forth with respect to the paint liquid film flowing out from the slit of the curtain flow coater, it is possible to prevent the paint liquid film from breaking. It has the advantage of not requiring skilled workers like conventional methods, as it can automatically detect this even when the paint is wet. Since it moves back and forth, it has the advantage of being able to detect breakage in any part of the paint liquid film in the middle direction.

Moreover, since the photoelectric detection device is arranged diagonally with respect to the paint film, the light that comes out from the projector and passes through the paint film is refracted by the paint film and its optical path is shifted, preventing it from entering the receiver. The first advantage is that there is no risk of malfunction and high reliability. That is, when a break occurs in the paint film, 100% of the light emitted from the projector enters the receiver, but when there is no break in the paint film, no light from the projector enters the receiver.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the conventional example, Fig. 2 is a perspective view of the same as above in a state where the film is broken, Fig. 3 is a perspective view of the present invention, and Figs. 4 a and b are cross sections of the same as above in a state where the film is not broken. In the figure and a cross-sectional view of the state where the film is broken, A is a photo spot detection device, 1 is a curtain flow coater, 2 is a slit, 3 is a light projector, 4 is a light receiver, and 5 is a paint liquid edge. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A photoelectric detection device consisting of a light emitter and a light receiver that moves back and forth in the width direction of the paint liquid film flowing out from the slit of the curtain flow coater is provided, and the photoelectric detection device is arranged diagonally with respect to the paint liquid film. A curtain flow coater equipped with a film breakage detection device.