METHOD FOR DETECTING UNCOATED PART OF COATING FILM USING FLOW COATER

摘要

PURPOSE:To detect an uncoated part of coating film automatically and accurately, by providing a reflective type phototube and a reflecting plate on both sides of the coating film of the flow coater, and moving them while maintaining corresponding relationship with each other. CONSTITUTION:A straight line between the reflective type phototube 3 and the reflecting plate 4 which are located on both sides of the coating film 2 is arranged so as to form a constant angle alpha of 90 deg. or less with respect to the coating film 2. The reflective type phototube 3 moves within the range shown by an arrow A, and the reflecting plate 4 moves within the range of an arrow B. In the case no uncoated part exsts, the light from the phototube 3 is reflected by the coating film 2, does not return to the phototube 3, and is scattered into the opposite direction. When any uncoated part exists, the light reaching the reflecting plate 4, is reflected by the plate, and returns to the phototube 3. The uncoated part is sensed by the returned light. If the phototube 3 and a conveyer 7 are linked together, the transfer of the object to be applied 8 is instantly stopped by detecting the defective part of the film, and the defective products are not manufactured.