Abstract: Method and arrangement for processing a paper or board web (1) or similar fibre web, in which method a processing mixture is spread onto the surface of the web. hi the method, the web (1) to be processed is lead from a press nip (8) and pressed between rolls (8) in this nip. Before the web enters the nip, such an amount of processing mixture is spread onto at least one side of the web (1), that the processing mixture is still wet when it enters the nip.

Abstract: A coating slip is applied to a first surface (SA) of a moving paper or board web using a gravity-based application method, the web's (W) direction of travel is turned by 120-200°, then a coating slip is applied to a second surface (SB) of the web using a gravity-based application method, and both sides (SA, SB) of the web are dried. The coating applicators include application beams (11, 16), which are located above the web and which have a supply gap or supply holes to pour out the coating slip with the aid of gravity on to the surface to be coated.

Abstract: A method and apparatus for coating a paper or a paper board web, comprising spreading coating mix having a solids content of 55-75% on the surface of the web with a nozzle applicator, levelling and metering the spread coating mix on the surface of the web by a doctor element capable of producing a high hydrodynamic force on the coating layer between the doctor element and the web, the doctor element being located downstream of the applicator so that the dwell time between the spreading of the coating mix to the metering is 72-2400 ms. The web speed is preferably 100-1000 m/s. A good smoothness and coverage is achieved by this method due to long dwell time.

Abstract: A method and apparatus for applying a coat mix to a high-speed running board or paper web by accurately premetering and pre-smoothing the applied coat with an applicator apparatus and then minimally doctoring the applied coat with an air knife. The applicator apparatus has a narrow slot-orifice extending in a cross-machine direction for facilitating high-speed laminar flow of coating mix into a gap region defined by confronting surfaces of the applicator apparatus and the web. The applicator apparatus has a member for directing the ejected coating mix in the gap region in a direction reverse to a travel direction of the web so that only a predetermined portion of the ejected coating mix is allowed to form an applied coat on the web. This accurate premetering of the coating mix by the applicator apparatus permits an operator to readily optimize the subsequent process of doctoring the applied coating with an air knife.

Abstract: A method and apparatus for applying a coat mix to a high-speed running board or paper web by accurately premetering and pre-smoothing the applied coal with an applicator apparatus and then minimally doctoring the applied coat with an air knife. The applicator apparatus has a narrow slot-orifice extending in a cross-machine direction for facilitating high-speed laminar flow of coating mix into a gap region defined by confronting surfaces of the applicator apparatus and the web. The applicator apparatus has a member for directing the ejected coating mix in tho gap region in a direction reverse to a travel direction of the web so that only a predetermined portion of the ejected coating mix is allowed to form an applied coat on the web. This accurate premetering of the coating mix by the applicator apparatus permits an operator to readily optimize the subsequent process of doctoring the applied coating with an air knife.

Abstract: A method and apparatus for controlling the coat profile in short dwell time coaters and similar apparatuses in which the coating mix is applied to the web, over a brief time interval, in an application chamber disposed immediately upstream of a doctoring element. Excess coating mix flows counter to the running direction of the web over the front edge of the application chamber. The distance between the web and the front edge of the coating chamber is adjustable, allowing the cross-machine profile of the coating to be controlled.

Abstract: Investigations have shown that curtailing the entry of air between the coater backing roll (3) and the web (5) being coated can offer a significant reduction in the number of uncoated blotches. By virtue of preventing the occurrence of such coat defects, the rotational speed of the kiss roll (2) in kiss roll coaters can be reduced. The invention is based on pressing the web (5) being coated against the backing roll (3) from the opposite side of the web (5) relative to the backing roll (3) at a point preceding the nip between the kiss roll (2) and the backing roll (3), whereby air is prevented from entering between the web (5) and the backing roll (3). The means employed for pressing the web (5) against the backing roll (3) is an air jet to avoid imposing additional stress on the web.

Abstract: A method and device for keeping a coating rod and a rod cradle in a bar coater clean and for preventing leakage of the lubrication and/or cooling water used in the bar coater is disclosed. The invention is intended for a bar coater in which the coating rod is, supported revolvingly in a rod cradle substantially over its entire length. The rod cradle is attached to the frame constructions of the coater. The rod cradle is also provided with at least one groove substantially parallel to the coating rod and open towards said coating rod, in which grooves(s) water is circulated to lubricate, cleanse and/or cool the coating rod and the rod cradle. The coating rod is loaded towards the base to be coated by loading the rod cradle.