Patent ID: 7694646

Claim:
A paper or board web curtain coater comprising; a nozzle unit having portions forming a longitudinally extending nozzle slot for coating color, and having a feeding chamber separated from the slot by a feeding chamber wall, the nozzle slot and the feeding chamber together extending in a longitudinal direction transverse to the paper or board web to be coated; a feeder pipe arranged for conveyed coating color into the feeding chamber; portions of the feeding chamber wall forming a plurality of successive feed holes having effective areas and spaced in the longitudinal direction, through which coating color can be conveyed from the coating chamber to the nozzle slot; and at least one structure movably mounted in the nozzle unit so that motion of the at least one structure is arranged to control flow of color coating from the feeding chamber through the feed holes to the nozzle slot, wherein the at least one structure is arranged to vary flow through the feed holes to accomplish transverse profiling of coating color flowing from the slot; wherein portions of the nozzle unit between said feed holes and the nozzle slot, form at least one equalizing chamber which also extends in the longitudinal direction of the coating apparatus so that the feed holes open into the equalizing chamber; and wherein the at least one structure movably mounted in the nozzle unit is a structure arranged in the equalizing chamber, said structure being positioned on a surface forming the equalizing chamber, said surface formed by portions of the feeding chamber wall through which the feed holes extend, and wherein the structure extends over a plurality of successive feed holes, said structure comprising a profiling member which is adjustable to change the effective areas of individual feed holes or groups of several feed holes for feeding a desired amount of coating color into the equalizing chamber at different points along the equalizing chamber in the longitudinal direction.