US 5,626,671 AGranted

Cross flow knife coater for applying a coating to a web

AssigneeMinnesota Mining and Manufacturing Company

InventorsKai Grimmel, Klaus Schmehl, Mark R. Strenger, Norbert J. Wallraff

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Abstract

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.

Claims10

Dependent claims

A coating apparatus for applying a coating fluid, having a thickness, on to a surface comprising:

means for providing relative movement between the coating apparatus and the surface;
means for applying coating to the surface, wherein the applying means comprises a trough, having a width, which extends transversely across at least a desired width of the coating, wherein the trough has an inner surface and an opening through which coating fluid exits onto the surface, and having first and second transverse ends, wherein the inner surface of the trough can be cleaned without disassembly of the trough and the trough opening prevents resistance to flow of the coating fluid;
means for feeding the coating fluid directly into the trough without requiring resistance to flow of the coating fluid for cross web distribution;
means for flowing the coating fluid across the width of the trough while coating fluid exits the opening;
and
a knife for regulating the thickness of the coating applied on the surface and for providing resistance to flow of the coating fluid;
wherein the means for providing relative movement between the coating apparatus and the surface and the means for flowing the coating fluid across the width of the trough combine to create a spiral flow of coating fluid within the trough and adjacent the trough opening.

4 more elements

Dependencies are inferred from the claim text.