Abstract: In a method of direct or indirect application of a liquid or viscous coating medium onto a moving material web, specifically a paper or cardboard web, a layer of the coating medium is applied to the material web by use of an applicator unit. The coating result is then checked for deviations from the desired coating result. In the event that such deviations are detected, and in order to correct them, at least one applicator unit operating parameter is adjusted. The adjustment is made within a short time period, and with the material web running, from an initial operating parameter value that is in effect prior to detection of the deviation. Subsequently, the operating parameter is then reset to at least approximately the initial parameter value, whereby the adjustment and the subsequent resetting may be repeated if necessary.

Abstract: In a method and apparatus for damping contact oscillations of rotating rolls in a paper machine, but notably in a coater, the rolls being held endways in bearings and at least two rolls forming with each other a nip, the damping is carried out actively, the active stimulation (phase-shifted counteroscillation) acting from outside directly and/or indirectly on at least one bearing point of one of the rolls.

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.

Abstract: An apparatus and process prevents and removes obstructions in the discharge opening of a metering slot of a coating apparatus, or fountain applicator, applying a coating medium onto a moving material web. The process repeatedly removes obstructions from the discharge opening of the metering slot, thereby preventing defects in the applied coating. The apparatus includes a scraper disposed and translatory movable within the discharge opening in a direction transverse to the direction of movement of the material web.

Abstract: The invention is directed to a method for the application of a liquid or pasty medium onto a traveling fiber material web. The medium is directly applied on at least one side of the traveling material web. The medium is pressed into the traveling material web after the medium is directly applied on the traveling material web.

Abstract: The invention relates to a method for directly or indirectly applying a liquid or pasty application medium (2) onto one or both sides of a continuous surface (4), wherein the application medium (2) is applied to the surface (4) in a plurality of single application regions by means of a plurality of single application nozzles (12) spaced apart from one another side by side and/or in succession in the direction of width (B) and/or longitudinal direction of the surface (4) and clearly distanced (D) from the surface (4), the application medium (2) emerging from each of these nozzles, wherein adjacent single application regions each intersect (U) at least in part in their respective edge regions, causing a layer of application medium to be produced across substantially the entire width (B) of the surface (4) to be coated. The invention also relates to an apparatus for performing this method.

Abstract: A method and apparatus for coating a traveling layer of material, in particular paper and/or cardboard. An applicator implement applies a predetermined and proper amount of a liquid or pasty medium onto an outer surface of a first rotating applicator roller which in turn transfers the liquid or pasty medium onto a first side of the moving layer of material just as it is moving through a press nip. A second layer of coating medium is applied indirectly with a second applicator implement onto an outer surface of a second rotating applicator roller from where it is transferred onto the previously coated side of the moving material layer while the first coat of coating medium is still wet.

Abstract: An applicator system roll for direct or indirect application of a coating medium onto a traveling fiber material web includes a core substantially comprised of a fiber composite material and a cover substantially surrounding the core.

Abstract: In an apparatus for the application of a liquid or pasty substance onto a traveling material web, notably of paper or cardboard, a doctor bar serving the metering of the applied substance is composed of at least two bar segments strung together in the longitudinal direction of the doctor bar and fixedly joined to one another. Possible thereby, in the manufacture of the doctor bar, is an easier handling and a better compliance with accuracy requirements.

Abstract: In a device for the coating of a running web of paper or cardboard, provisions are that in a press gap formed between two rolls a coating substance applied in a very small quantity on the surface of the one roll is first pressed on the web leaving a very thin coat on the web which, however, covers all spots including the "mounds" of microroughness. Next, the second coat can be applied and dosed on the still moist first coat with the usual means. In the process, the first coat is preferably dosed on the shell of the first roll, by means of the peripheral grooves of a rotary doctor. The same may be performed also as regards the second coating on the web.

Abstract: The invention is directed to a method and device for the production of a paper web featuring a CF coating. The paper web passes through a nip (a) formed by a coating roll (2) and a backing roll (1). CF coating is applied on coating roll (2), dosed there by means of a dosing device (11) and transferred to paper web (3) in the nip, with the two rolls (1, 2) being compressed at a line force of maximally 10 kN/m.

Abstract: A method for at least one-sided coating of a material web with an application medium is performed by a two-element applicator device having at least one applicator roll and a counter element defining a gap through which the material web is conveyed. The method includes the steps of pre-metering the application medium onto the applicator roll and transferring the application medium onto the material web in the gap. Pre-metering of the application medium to the applicator device is performed by at least one free jet.

Abstract: An application unit for applying a liquid or pasty medium onto a surface moving past the application unit. This has particular application to direct or indirect application of such a medium to a paper or board web. A support beam and a front wall supported generally further from and a rear wall supported generally closer to the moving surface. The walls are spaced apart for defining a pasty medium supply gap between them and are oriented so that the supply gap generally directs the medium toward the surface. The front and rear walls can selectively receive releasable attachment of members for forming a liquid medium an application chamber, the chamber having a downstream end with a blade, an upstream end with a damming strip over which the excessive medium in the application chamber can overflow. Alternatively, a second set of attachable members may be attached to the walls for forming a free jet nozzle dosing gap that communicates with the supply gap for directing the medium to the surface.

Abstract: The invention is directed to an applicator for coating a traveling fiber web with a coating mixture. The applicator includes a backing roll having a shell surface for carrying the web, and a nozzle for feeding the coating mixture. The applicator includes a support beam; a nozzle which is integral with or connected to the support beam; and a doctor bar carried by the support beam. The doctor bar has a guide surface. The guide surface and the backing roll define a nip for producing a hydrodynamic pressure. The guide surface approaching the shell surface of the backing roll extends to an exit edge at a location nearest the backing roll. A device is provided for flexibly backing the doctor bar on the support beam.

Abstract: A coating system for material webs, specifically of paper or cardboard, includes two mutually parallel rolls directly coordinated with each other, the rolls having a mutually variable spacing such that the rolls can be positioned to create a press gap for coating the web, or so as not to create a press gap. When the rolls are not positioned to form a press gap, the web passes over both roll shells while circumventing the applicators which have already dosed the roll shells with a coating mixture. The web passes over both roll shells for purposes of transferring the coating mixture predosed by the applicators. Solely the web pull in conjunction with the wrap angle of the two roll shells serves the final dosing by scraping off an excess quantity from the roll shells.

Abstract: Disclosed are a process of and an apparatus for producing paper webs coated on both sides, in particular so-called LWC-papers, in a paper making machine. Firstly, one side of the paper web (1) is coated in a first coating station (8) and then dried. Subsequently, the other side of the paper web (1) is coated in a second coating station (25) and then dried. Each coating station (8, 25) includes an application role (10), an opposing roll (11) and an application unit (13) arranged on the application roll for indirectly coating the paper web. The metering of the coating mass on the application roll (10) takes place by means of a smooth roll doctor. The coated paper web (1) is calendered by means of an on-line calendering unit (60).

Abstract: A device for predosing coating composition on a traveling web of paper. A guide member extends obliquely toward the web. Downstream in the path of the web past the guide member, a doctor element is supported spaced from the tip of the guide member for defining a pressure space between the a guide member and the doctor element. Coating composition is fed through a feed channel between the guide member, on the one hand, and the doctor element and the supports for the doctor element up to the pressure space, on the other hand. An exit slot from the pressure space between the guide member and the web is defined at the tip of the guide member. The guide member has a guide surface down from the tip of the guide member, on the side of the guide member away from the doctor element which faces generally toward the web. The guide surface defines a return channel for coating composition that has moved out of the pressure space and through the slot.

Abstract: The invention concerns a coating system with at least one web support roll and at least one corresponding metering roll coordinated with it and having a grooved surface essentially in peripheral direction or in the form of a threading, for metering the coating substance in the gap existing between the web support roll and the metering rolls. A groove forming or groove truing system can be infed in the operation of the coating system can be infed onto the metering rolls.

Abstract: A device for coating a paper web includes two applicator rolls disposed parallel to one another, forming a roll gap for the passage of a paper web therethrough. At least one applicator for applying a coating onto a surface of at least one of the rolls is also provided. The coating roll thereafter transfers the coating onto one side of a paper web disposed in the roll gap. Guide elements disposed downstream of the roll gap with respect to a direction of travel of the paper web through the device include at least one beam-like air guide element adapted to create an air cushion-between the paper web and a surface of the air guide element facing the paper web. The air guide element is disposed in such a manner as to deflect a paper web at least once downstream the roll gap. At least one air guide element is disposed directly downstream of the roll gap at a distance from the roll gap of about 0.3 times to about 1 time the diameter of at least one of the rolls.

Abstract: A coating device having a blade for metering a coating material onto a running web of paper or cardboard guided by a roll includes at least one noncontacting sensor disposed near the blade and between apparatus for adjusting the transverse profile of coating. The sensor provides a signal indicating the position of the blade. The device also includes a receiver for receiving the signal of the sensor and a control device for controlling the angular position of the blade as a function of the sensor signal. The angle of contact of the blade on the roll is determined as a function of the known pressing pressure (or a corresponding proportional value thereof) of the blade caused by the profile adjustment apparatus, preferably determined by a computer or microprocessor.