Minnesota Mining and Manufacturing Company

Other

Omar D Brown

Gary W Maier

Robert A Yapel

Daniel V Norton

Bernard A Scheller

Wayne P Ray

Manley C Marcellus

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

A die coating apparatus includes a die having an upstream bar with an upstream lip and a downstream bar with a downstream lip. The upstream lip is formed as a land and the downstream lip is formed as a sharp edge. A low surface energy covering is applied to the surface of the downstream bar adjacent to the sharp edge, and to the surface of the land, adjacent to its downstream edge. This presents a generally undulating surface. The low surface energy coverings need not extend completely to the edges of the downstream bar and the land.

Die coating apparatus with surface covering

A slide die coating method and apparatus includes a die having an upstream bar with an upstream lip, a manifold bars a downstream bar with a downstream lip, a vacuum bar, and a slide surface. The upstream lip is formed as a land and the first manifold bar is formed as a sharp edge. The coating fluid exits the die from a passageway and slides along the slide surface to form a continuous coating bead between the manifold bar sharp edge, the upstream die lip, and the surface being coated. The shape of the land conforms to the shape of the surface being coated. The die can include multiple passageways for coating multiple layers.

Slide die coating method and apparatus with improved die lip

A die coating method and apparatus includes a die having an upstream bar with an upstream lip and a downstream bar with a downstream lip. The upstream lip is formed as a land and the downstream lip is formed as a sharp edge. The shape of the land conforms to the shape of the surface being coated. Changing at least one of the slot height, the overbite, and the convergence can improve coating performance. A replaceable, flexible strip can be used above the coating slot to facilitate replacement of a damaged overbite edge. The strip can be held in position by vacuum applied through the downstream bar.

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Saint Paul, MN, United States of America

Omar D Brown