Abstract: An arrangement in a curtain coater for starting and stopping coating of a web, having a reservoir and a connected surface extending over the web toward the curtain to collect the coating as the coater moves over the web to start coating the web. A cover plate that swing around a cross-direction shaft connected to the cover plate. In one embodiment the shaft also moves in the machine direction. The cover plate is used to protect an leading edge of the collecting surface from being covered with coating and pivots to be cleaned with fluid which may be supply from the shaft. The cover plate is arranged so the fluid drain off the cover plate onto the collecting surface or reservoir. When clean, the cover plate is repositioned to protect an leading edge of the collecting surface during the next start or stop operation of coating the web.

Abstract: An arrangement in a curtain coater for starting and stopping coating of a web, having a reservoir and a connected surface extending over the web toward the curtain to collect the coating as the coater moves over the web to start coating the web. A cover plate that swing around a cross-direction shaft connected to the cover plate. In one embodiment the shaft also moves in the machine direction. The cover plate is used to protect an leading edge of the collecting surface from being covered with coating and pivots to be cleaned with fluid which may be supply from the shaft. The cover plate is arranged so the fluid drain off the cover plate onto the collecting surface or reservoir. When clean, the cover plate is repositioned to protect an leading edge of the collecting surface during the next start or stop operation of coating the web.

Abstract: A method and apparatus for exhausting gas from a coating material. The coating material is fed in the bottom part area of a drum (3) rotating around an essentially vertical axis inside a vacuum tank (1), whereby the rotating motion of the drum causes the coating material to rise up the inner wall of the drum and to discharge from the upper edge of the drum as a thin film against the inner wall of a vacuum tank, wherefrom the coating material flows downwards. The coating material is arranged to rise up the wall of the drum stepwise, so that the coating material will form a thin veil-like film on at least two different step levels (10-12), whereupon the gas bubbles in the coating material will break and be discharged from the coating material.

Abstract: A method and apparatus for exhausting gas from a coating material. The coating material is fed in the bottom part area of a drum (3) rotating around an essentially vertical axis inside a vacuum tank (1), whereby the rotating motion of the drum causes the coating material to rise up the inner wall of the drum and to discharge from the upper edge of the drum as a thin film against the inner wall of a vacuum tank, wherefrom the coating material flows downwards. The coating material is arranged to rise up the wall of the drum stepwise, so that the coating material will form a thin veil-like film on at least two different step levels (10-12), whereupon the gas bubbles in the coating material will break and be discharged from the coating material.

Abstract: A paper/board web is coated with a plane-fed curtain coater having a nozzle beam (40) with at least one feed chamber (12) and a nozzle slot (30) in connection therewith for feeding at least one layer of coating material onto a flow plane (35) established by the nozzle beam (40). The cross-thickness profile of said at least one coating material layer (2) on top of the flow plane (35) downstream of the feed slot (30) associated with the discussed layer is determined, and, on the basis thereof, the feed rate of the coating material layer from the feed chamber (12) to the feed slot (30) is subjected to a manipulation profiled crosswise of a web (W) to achieve a desired cross-profile for the at least one coating material layer.

Abstract: A treating agent is fed to an application apparatus (40) used for applying coating color or surface size directly or indirectly to a paper or board web. Part of the treating agent fed to the application apparatus (40) is returned via a bypass line (24) to the treating agent feed system and part of it is passed into an application chamber in the application apparatus (40), from which application chamber substantially all treating agent fed into it is applied to a moving web or to a transfer surface. The flow of a treating agent (Q) to the application apparatus (40) is measured, and the feeding of the treating agent is controlled on the basis of the measured flow (Q) and of a predetermined set value (Q0), which set value has been selected according to the desired amount of treating agent to be applied to the moving web or transfer surface.