Abstract: A method for operating a sheet-forming unit of a papermaking machine. At least one fibrous material suspension is fed to a headbox and is conducted in a plurality of turbulence-generating channels to form sub-flows, and fed to a nozzle. From the nozzle, the at least one fibrous material suspension is in the form of a free jet into the forming unit to define an impingement line. In a final fluidization region of an individual turbulence-generating channel a pressure loss (?p) of ?50 mbar is generated within the fibrous material suspension before inlet thereof into the nozzle, and the fibrous material suspension is guided from the final fluidization region as far as the impingement line in such a way that the dwell time of the suspension in the region defined by the final fluidization region as far as the impingement line ranges from >30 ms to ?300 ms.

Abstract: The invention relates to a method for optimizing the energy balance of a forming section in a machine for producing fibrous webs, in which a fiber suspension, which is fed to the forming section by way of a material ramp after the immobility point is reached, is passed through at least two dewatering units within a compression zone and to a subsequent functional unit. The invention is characterized in that a setpoint value for a target dryness to be set is predefined based on the existing dewatering elements as a function of a theoretical maximum achievable dryness under plant conditions in the area of the transition zone, said setpoint being selected such that it is less than the theoretical maximum achievable dryness but is equal to or greater than a required minimum dryness in the area of the transition zone, and that the target dryness is controlled by lowering the inlet dryness at one of the last dewatering units disposed in the direction of passage of the fiber suspension within the compression zone.

Abstract: A forming section in a machine for producing a web of fibrous material includes a control and/or regulating system including a control and/or regulating device which is connected with at least one device for at least indirect acquisition of one value at least indirectly characterizing the dry content of the fibrous web in a transfer area from the forming section to a following function unit, with a device for input of a desired value for the target dry content, and with at least the control elements of an individual dewatering unit located prior to one of the last dewatering units, or the last dewatering unit inside the compression zone. The control and/or regulating device also includes a device for creating the control variables for controlling the individual dewatering units.

Abstract: The invention relates to a headbox for a machine for producing a fibrous web, in particular a paper or cardboard web, from at least one fibrous stock suspension, having a feed apparatus which feeds the at least one fibrous stock suspension, having a distributor-pipe perforated plate which is adjacent downstream and has a multiplicity of channels which are arranged in rows and in columns, having an intermediate channel which lies downstream of the latter, extends over the width of the headbox and has a plurality of means which are spaced apart from one another in the width direction of the headbox for the preferably regulatable/controllable metering of a fluid in fluid part streams into the at least one fibrous stock suspension.

Abstract: A method for operating a sheet-forming unit of a papermaking machine. At least one fibrous material suspension is fed to a headbox and is conducted in a plurality of turbulence-generating channels to form sub-flows, and fed to a nozzle. From the nozzle, the at least one fibrous material suspension is in the form of a free jet into the forming unit to define an impingement line. In a final fluidization region of an individual turbulence-generating channel a pressure loss (?p) of ?50 mbar is generated within the fibrous material suspension before inlet thereof into the nozzle, and the fibrous material suspension is guided from the final fluidization region as far as the impingement line in such a way that the dwell time of the suspension in the region defined by the final fluidization region as far as the impingement line ranges from >30 ms to ?300 ms.

Abstract: A headbox includes a feed device feeding the fibrous material suspension, a nozzle, and a turbulence-generating device. The fibrous material suspension is guided in the turbulence-generating device in sub-flows through turbulence-generating channels. Within the individual turbulence-generating channel of the turbulence-generating device, at least one region forming a fluidization region is provided, in which a pressure loss can be generated in the sub-flow of the fibrous material suspension guided through said region. The nozzle and the turbulence-generating device are designed and dimensioned such that they are suitable for setting a dwell time of ?200 ms of the fibrous material suspension flowing through the same from a final fluidization region of an individual turbulence-generating channel before inlet into the nozzle as far as the outlet gap of the nozzle, and a pressure loss of ?50 mbar in the final fluidization region upstream of the inlet into the nozzle.

Abstract: A forming section in a machine for producing a web of fibrous material includes a control and/or regulating system including a control and/or regulating device which is connected with at least one device for at least indirect acquisition of one value at least indirectly characterizing the dry content of the fibrous web in a transfer area from the forming section to a following function unit, with a device for input of a desired value for the target dry content, and with at least the control elements of an individual dewatering unit located prior to one of the last dewatering units, or the last dewatering unit inside the compression zone. The control and/or regulating device also includes a device for creating the control variables for controlling the individual dewatering units.

Abstract: The invention relates to a headbox for a machine for producing a fibrous web, in particular a paper or cardboard web, from at least one fibrous stock suspension, having a feed apparatus which feeds the at least one fibrous stock suspension, having a distributor-pipe perforated plate which is adjacent downstream and has a multiplicity of channels which are arranged in rows and in columns, having an intermediate channel which lies downstream of the latter, extends over the width of the headbox and has a plurality of means which are spaced apart from one another in the width direction of the headbox for the preferably regulatable/controllable metering of a fluid in fluid part streams into the at least one fibrous stock suspension.

Abstract: The invention relates to a method for optimizing the energy balance of a forming section in a machine for producing fibrous webs, in which a fiber suspension, which is fed to the forming section by way of a material ramp after the immobility point is reached, is passed through at least two dewatering units within a compression zone and to a subsequent functional unit. The invention is characterized in that a setpoint value for a target dryness to be set is predefined based on the existing dewatering elements as a function of a theoretical maximum achievable dryness under plant conditions in the area of the transition zone, said setpoint being selected such that it is less than the theoretical maximum achievable dryness but is equal to or greater than a required minimum dryness in the area of the transition zone, and that the target dryness is controlled by lowering the inlet dryness at one of the last dewatering units disposed in the direction of passage of the fiber suspension within the compression zone.

Abstract: Papermaching clothing for conveying a fibrous web in a machine for producing the fibrous web, whereby a fabric made of fibers which run in the machine direction and in the transverse direction, is disclosed having circular fibers, flat fibers or, as compared with the plane of the clothing formed by them, flattened fibers, such as fibers having an elliptical cross section.

Abstract: The present invention relates to a method and a corresponding plant for producing a fibrous web, in particular a paper web, paperboard web or tissue web. The formation of the fibrous web is defined online as a controlled variable and is held at a preselectable set-point level by way of an automatic formation control system.

Abstract: The present invention relates to a twin wire former in a machine for the production of a fiber web, especially a paper or cardboard web from at least one fiber stock suspension, including a vertical twin wire segment having two wires running over a peripheral area of a turning element, especially a guide roll whose surface is preferably not equipped with suction and is smooth or substantially smooth; and in that at least one separation element, such as a transfer suction box is provided indirectly or immediately following the guide roll that separates the top wire from the bottom wire on which the fibrous web is supported.

Abstract: Papermaching clothing for conveying a fibrous web in a machine for producing the fibrous web, whereby a fabric made of fibers which run in the machine direction and in the transverse direction, is disclosed having circular fibers, flat fibers or, as compared with the plane of the clothing formed by them, flattened fibers, such as fibers having an elliptical cross section.

Abstract: A gap former for forming a fibrous web from a fibrous suspension supplied via a headbox, having a top fabric (3, 28) and a carrier or bottom fabric (2, 27), is defined by the fact that the carrier fabric (2, 27) has a greater thickness than the top fabric (3, 28).

Abstract: Process for application of a coating medium on a traveling material web that is one of paper and cardboard, the coating medium including at least one of a pasty medium and a liquid medium, wherein the process includes forming a material web in a wet section of a machine for one of paper and cardboard and guiding the material web which is still wet with a traveling, endless, carrier belt during application of a coating medium. The application of the coating medium includes transferring the coating medium from a roll-coating mechanism to at least one transfer belt onto the still wet material web. The coating medium is transferred from a surface of the at least one transfer belt moving in a direction of travel of the material web. The at least one transfer belt is a traveling, endless, air-permeable transfer belt which is guided by rolls. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Abstract: The invention relates to a twin wire former for the production of a fiber web specifically a paper, cardboard or tissue web, from a fiber suspension. The invention is characterized in that the rotating forming roll has an open volume and is a non-suction type; the rotating forming roll has a forming roll diameter of less than 1,400 mm; the rotating forming roll has a forming roll angle of wrap of less than 70°; a forming suction box is located immediately downstream from the rotating forming roll as viewed in direction of wire travel; and in the area of the wedge-shaped inlet nip, the fiber stock suspension has a stock density of between 0.4% and 2.0%, preferably between 0.6% and 1.5%. These characteristics result in an improved forming quality and web quality.

Abstract: The present invention relates to a twin wire former in a machine for the production of a fiber web, especially a paper or cardboard web from at least one fiber stock suspension, including a vertical twin wire segment having two wires running over a peripheral area of a turning element, especially a guide roll whose surface is preferably not equipped with suction and is smooth or substantially smooth; and in that at least one separation element, such as a transfer suction box is provided indirectly or immediately following the guide roll that separates the top wire from the bottom wire on which the fibrous web is supported.

Abstract: The invention relates to a twin wire former for the production of a fiber web specifically a paper, cardboard or tissue web, from a fiber suspension.

Abstract: A gravure paper and a method of manufacturing gravure paper having a maximal roughness depth of approximately 1.40 &mgr;m. The method utilizes a paper machine including a forming system, a first press section, and a drying section, and includes producing a stock suspension including a stock having a freeness of greater than or equal to approximately 50 ml CSF, forming an unfinished fibrous material web from the stock suspension, and applying at least one of a pigment and a filler slurry to the unfinished fibrous material web between a beginning of the forming system and a position at which the dry matter content of the unfinished fibrous material web is approximately ≦90%.

Abstract: A papermaking machine and a method for applying an application medium to a moving web of material in a papermaking machine. The papermaking machine has a wet end section, a press section, a drying section and an applying device for applying a medium to a moving web of material. The wet end section includes a twin wire area having a first wire and a second wire wherein the web of material is formed and positioned between the two wires and separated from the two wires before moving to the press section. At least one wet end section applying device is positioned on one side of at least one of the first wire or the second wire within the twin wire area and facing away from the web of material positioned on the wires. The press section of the papermaking machine has a first press element and at least one press section applying device facing directly toward the web of material.