Coating device and coating method
AssigneeVoith Sulzer Papiertechnik Patent GmbH
InventorMartin Kustermann
Life of this patent
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Abstract
A device for the application of a liquid or viscous coating medium onto a moving material web, specifically a paper or cardboard web, includes a curtain coater to apply the coating medium in the form of a curtain or veil to the material web and a suction device to remove air which is carried along by the material web and/or the veil of coating medium. A dynamic pressure analyzer determines the pressure of the air that accumulates before the line of contact of the curtain of coating medium with the moving material web, when viewed in the direction of travel of the moving material web. A control unit controls the suction power of the suction device relative to the determined dynamic pressure.
Claims28
An applicator device for the application of a coating medium onto a moving fiber material web, the moving fiber material web having a direction of travel and a coating surface, the coating surface carrying a first air boundary layer, said applicator device comprising:
- a first applicator unit configured to discharge a veil of coating medium onto the coating surface of the material web at a line of contact, the veil of coating medium carrying a second air boundary layer;
- at least one suction device having a suction power, said at least one suction device being configured for at least partially removing by suction at least one of said first air boundary layer and said second air boundary layer, said at least one suction device being disposed prior to said line of contact relative to the direction of travel of the material web;
- a dynamic pressure analyzer configured for measuring a dynamic air pressure at a point prior to said line of contact relative to the direction of travel of the material web, said dynamic pressure analyzer providing a pressure signal indicative of said dynamic air pressure;
- and
- a control unit electrically coupled to said dynamic pressure analyzer, said control unit being configured for receiving said pressure signal and controlling said suction power of said at least one suction device dependent at least in part upon said pressure signal.
A method for the application of a coating medium onto a moving fiber material web, the moving fiber material web having a direction of travel and a coating surface, the coating surface carrying a first air boundary layer, said method comprising the steps of:
- providing a first applicator device, said applicator device discharging a veil of coating medium onto the material web at a line of contact, the veil of coating medium carrying a second air boundary layer;
- removing with at least one suction device at least a portion of at least one of said first air boundary layer and said second air boundary layer, said at least one suction device having a suction power;
- sensing a dynamic air pressure at a point prior to said line of contact relative to the direction of travel of the moving material web;
- and
- controlling said suction power of said at least one suction device dependent at least in part upon said sensing step.
Dependencies are inferred from the claim text.