Abstract: A method for controlling the deflection and/or position of a deflection-compensated doctor blade support beam relative to a web. The movement range of the doctor blade support beam is divided into radial control sectors so that the working directions of compensation elements in the support beam essentially form interface limits of the radial control sectors. When the support beam is to be moved, a set point is selected toward which a reference point of the support beam should move. The specific control sector is then determined within which the set point is located and this control sector becomes the active control sector. Deflection of the doctor blade support beam employs these two compensation elements so that one is used for controlling the deflection in the x-axis direction of the coordinate system, while the other is used for controlling the deflection in the y-axis direction of the coordinate system.

Abstract: A curtain coater and a curtain-coating method for coating a moving web of paper or board are described. The curtain coater has an applicator nozzle for applying a coating mix to the surface of the web in the form of a continuous curtain extending uniformly over the cross-machine width of the web. In one aspect, a doctoring means located upstream (in terms of the direction of travel of the web) from the applicator nozzle substantially removes the air boundary layer traveling on the surface of the web. In another aspect, the doctoring means comprises a suction nozzle for removing the air boundary layer. In yet another aspect, a gas nozzle located downstream from the applicator nozzle sprays gas on the coating curtain in order to help apply the coating mix to the surface of the web.

Abstract: The present invention relates to a method for coating a web (2) of paper or paper board moving supported by a backing roll (1) or for coating a roll of a film-transfer press, the method comprising the steps of doctoring the surface of the web (2) or the roll of the film-transfer press, and applying the coating mix to the surface of the web (2) or the roll of the film-transfer press. A cooling fluid is applied to the meeting point of the surface (2) to be doctored and the doctoring element (3) prior to the start of coating mix application.

Abstract: An apparatus for applying a treating mix onto the surface of a moving device in the coating of paper or board. The apparatus comprises a blade carrier (3), doctor means (4) attached to the blade carrier (3), a front wall (9) positioned a distance from the doctor means (4), a device (1) constituting the moving device, said device being arranged in conjunction with the front wall (9) and the doctor means such that it forms a chamber (6, 7) with the front wall (9) and the doctor means, and means (8) for supplying treating agent into an area of the application chamber (6, 7) which is at least essentially opposite to the moving surface. To prevent streaks, a screen plate (10) is fitted in the application chamber, at least partly dividing the application chamber (6, 7) such that with regard to the screen plate (10), the doctor means (4) is arranged on the opposite side thereof to the feed means for the treating agent.

Abstract: The present publication discloses a method for controlling the deflection and/or position of a deflection-compensated doctor blade support beam relative to web such as a paper or paperboard web. The invention is based on dividing the movement range of the doctor blade support beam, that is, the spatial range within which the reference point of the support beam can be moved with the help of the compensation elements, into radial control sectors so that the working directions of the compensation elements essentially form the interface limits of the radial control sectors. When it is desired to move the support beam, a set point is selected toward which the reference point of the support beam should move. After the position of the set point is established, the specific control sector is determined within which the set point is located and the thus identified control sector is selected as the active control sector.