Cross flow knife coater

A cross flow knife coater includes a coating station through which a surface passes and a trough which extends transversely across the desired width of the coating. The trough has an opening through which coating fluid exits onto the surface without using a slot, and first and second transverse ends. The coating fluid is fed directly into the trough at a first transverse end, and is moved from the first transverse end of the trough, across the trough, and toward the second transverse end to cause the coating fluid to flow across the width of the trough while coating fluid exits the opening. The coater creates a spiral flow of coating fluid across the width of the trough which carries debris, bubbles, and other undesirables across the trough to a second traverse end where they can be vented. The perpendicular distance between the trough opening and the surface, and likewise between the knife and the surface, can be adjusted.