Minnesota Mining and Manufacturing Company

3M Innovative Properties Company

Daniel V Norton

Robert A Yapel

Aparna V Bhave

Thomas M Milbourn

Lawrence B Wallace

Hans E Iverson

Omar D Brown

Bernard A Scheller

Wayne P Ray

Manley C Marcellus

A method and apparatus for coating a moving web with a coating fluid. The coating die has at least one feed slot for supplying the coating fluid to the moving web and a front face demarked from the at least one feed slot by a die edge. A guide mechanism guides the moving web in a first direction past the coating die such that a coating bead is formed in a gap between the moving web and the die edge. The spraying system sprays a cleaning fluid on at least a portion of the front face of the slide coating die such that the coating bead forms a substantially linear static wetting line on the front face of the coating die.

Die edge cleaning system

A method and apparatus for coating and drying coated substrates without introducing significant surface imperfections while running at higher web speeds than known drying methods. The substrate is preferably coated within the drying enclosure or the coating bead may form a closure at the entrance of the drying enclosure. The substrate is moved through a first drying enclosure along a first axis. The first drying enclosure is substantially isolated from an external environment. A first low velocity, substantially laminar flow field of a drying gas is directed across the front surface of the substrate. The first flow field is generally parallel to the front surface and generally perpendicular to the first axis to minimize the formation of surface imperfections during the evaporation of the coating solvent. The substrate may then be moved to subsequent drying enclosures through transition enclosures that minimize surface imperfections due to high velocity interaction between the adjacent drying enclosures. In embodiments where the first axis is in an inclined configuration with respect to horizontal, louvers may be utilized for directing solvent evolving from the substrate to minimize surface imperfections due to solvent cascade.

Apparatus and method for drying a coating on a substrate

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Saint Paul, MN, United States of America

Daniel V Norton