Abstract: A method for controlling a fiber fractionation system for fractionating an input material into a long fraction (LF) stream comprising LF fibers and a short fraction (SF) stream comprising SF fibers includes measuring an average LF fiber length at one or more locations post-fractionation, and maintaining the average LF fiber length within a target variability range by automatically altering a rotational speed of a rotor of the fiber fractionation system.

Abstract: A sheet manufacturing apparatus includes a defibrating unit that defibrates a raw material containing a fiber in air; a mixing unit that mixes a defibrated material defibrated by the defibrating unit and a resin in air; a web forming unit that forms a web by accumulating the mixture mixed by the mixing unit on a moving body; a transporting unit that transports the web; a sheet forming unit that forms a sheet from the web; a setting unit that sets a thickness of the sheet; and a controller that controls a moving speed of the moving body and a transporting speed of the web transported by the transporting unit, in accordance with the thickness of the sheet set by the setting unit.

Abstract: The present invention relates to a casting apparatus for the production of a cast web of homogenized tobacco material, said casting apparatus comprising • o a casting box (4) adapted to contain a slurry of said homogenized tobacco material; • o a movable support; • o a casting blade (6) adapted to cast the slurry contained in the casting box onto the movable support so as to form the cast web; • o wherein said casting blade has a transverse cross section defining a blade edge, said blade edge including a first point having a first radius of curvature and a second point having a second radius of curvature, said first and second radii of curvature being comprised between about 1 and about 500 and being different from each other.

Abstract: There is disclosed a controller (120) for controlling the speed of a cooling device (118) in an electronic apparatus (100), an apparatus (100), a storage enclosure (102) and a method of configuring an apparatus (100). The controller (120) is constructed and arranged to determine a speed value for the cooling device (118) in accordance with a temperature input received from a temperature sensor (122) associated with the apparatus, the speed value being selected from a set of N speed values. The controller is arranged to control the speed of the cooling device in accordance with the selected speed value. The step between at least one pair of adjacent speed values in the set is different from the step between another pair of adjacent speed values in the set.

Abstract: A sheet manufacturing apparatus is provided with a screen portion in which introduced material is passed through a plurality of openings; an information acquiring unit configured to acquire at least one of inflow information related to a flow rate of the material that flows into the screen portion and outflow information related to a flow rate of the material that passes through the screen portion; and a controller configured to make a determination that a clogging of the screen portion is generated when the flow rate is reduced based on at least one of the inflow information and the outflow information.

Abstract: A sheet manufacturing apparatus is provided with a screen portion in which introduced material is passed through a plurality of openings; an information acquiring unit configured to acquire at least one of inflow information related to a flow rate of the material that flows into the screen portion and outflow information related to a flow rate of the material that passes through the screen portion; and a controller configured to make a determination that a clogging of the screen portion is generated when the flow rate is reduced based on at least one of the inflow information and the outflow information.

Abstract: A pulp pre-processor for the papermaking industry uses pulp fiber analyzers to determine the distribution of fiber parameters, such as length, curl or coarseness from a feed source, such as recycled pulp, and mixes metered portions of pulp from augmenting pulp sources on an as-needed basis to provide a uniform distribution of a particular fiber parameter while maximizing use of recycled pulp.

Abstract: A method and a system for controlling the manufacturing or finishing process of a fiber web at a transition stage of the process. In the method a corrected error profile (PD?k) is formed using an error profile (PD). Using the corrected error profile (PD?k) at least one control signal (CAk) is determined for the actuators (6) of the manufacturing or finishing process of a fiber web.

Abstract: A papermaking raw material processor capable of reforming pulp in papermaking a process using cavitation includes a first pump 5 jets jet liquid and second pump 6 jets suspension containing; e.g., pulp fibers into a processing unit inside which cavitation is generated by generation of a jet stream. Inside processing unit 2, a jet stream generates cavitation to carry out a reforming processing in which ink, or the like, is removed from the fibers by a blast resulting from collapse of cavitation bubbles generated there. The liquid after reforming processing is returned to second tank 4, except for a part of it fed to downstream steps, while the suspension is processed, as circulated between processing unit 2 and second tank 6.

Abstract: A fluid transfer apparatus for bulk material is disclosed. The transfer apparatus includes a rotor mounted on a rotatable shaft and including axially extending flow channels extending through the rotor parallel to the shaft, flow connectors for connecting a low-pressure flow of fluid and a high-pressure flow of fluid into and out of the axially extending flow channels, a casing enclosing the rotor, a pair of axially sealing plates disposed between the ends of the rotor and the casing, a pressurizing fluid fed into the chamber defined by the casing to pressurize the rotor, the flow connectors, and the axially movable sealing plates.

Abstract: A procedure and arrangement to control the lamella of a headbox's lip channel, when the mass flow goes in the headbox (3) through the lip channel (2), in which case single mass flows are held separate from each other with the lamella (1) before the flows are united after the lamella. The lamella's dimensions, mechanical characteristics and/or dynamic characteristics are changed at least in the lamella's border area with an active structure, which is active and/or passive active tool and/or active and/or passive active material.

Abstract: A papermaking raw material processor capable of reforming pulp in papermaking a process using cavitation includes a first pump 5 jets jet liquid and second pump 6 jets suspension containing; e.g., pulp fibers into a processing unit inside which cavitation is generated by generation of a jet stream. Inside processing unit 2, a jet stream generates cavitation to carry out a reforming processing in which ink, or the like, is removed from the fibers by a blast resulting from collapse of cavitation bubbles generated there. The liquid after reforming processing is returned to second tank 4, except for a part of it fed to downstream steps, while the suspension is processed, as circulated between processing unit 2 and second tank 6.

Abstract: A device and a method for on-line control of the fibre direction of a fire web (8), being manufactured from stock delivered from a headbox (3) through a discharge opening (11) defined by movable lips (9, 10), while using a fibre direction meter (12) located downstream and actuating members (14), which are allonged long the lips for regulation of the discharge opening as a response to individual control signals, each being a function of measured fibre direction values; wherein a control unit (13) receives the measured fibre direction values, calculates the control signals, and transmits these to the actuating members. According to the invention, the control unit identifies an array of fibre direction values, originating from positions in the cross direction of the fibre web which correspond to the positions of the actuating members. The control unit then compares the array of fibre direction values with an array of desired fibre direction values.

Abstract: The invention presents a pulp concentration adjusting method and its device for realizing a used paper recycling apparatus being installed in a room of a small shop or the like, friendly to the environment, low in running cost, and capable of maintaining a high confidentiality. The pulp concentration adjusting section is characterized by dividing a specified portion from the whole volume of used paper pulp manufactured in pulp making section in preceding process, adding water for adjusting concentration to the divided portion of used paper pulp, and adjusting the total volume of the divided portion of used paper pulp and water to a specified value, thereby preparing a pulp suspension of specified concentration. In this manner, by adjusting the concentration of used paper pulp in dividing portions (small portions), the water consumption can be saved substantially and the apparatus size is reduced, while enhancing the processing capacity.

Abstract: In a papermaking system having a headbox to dispense a jet of liquid and paper forming fibers, an improvement comprising at least one sensor arrangement for simultaneously or sequentially measuring in at least one location the jet velocity or jet flow correlation of the jet at plural known angles relative to the machine direction. The measured data is analyzed to generate a velocity vector profile or velocity direction profile of the jet, and hence to determine the profile of fiber orientation angles laid down in the sheet formed of the jet.

Abstract: In order to observe the dry line formed on the surface of wood fibre pulp on the moving wire in a Fourdrinier paper machine, its—atrea of appearance is scanned at a low angle with a thin beam cluster (A1, B1) which, being generated by a laser radiation source (20) and representing one or more discrete wavelengths, is distinguishable from the background light. Hereby the surface following the dry line (I) reflects diffusively a major part and specularly a minor part of the arriving radiation than the surface preceding it. A detector (30) located above the level of the wire observes the intensity of the diffusely reflected radiation (A3, B3) hitting it and delivers continuously, as the beam cluster scans the pulp surface, a signal which is proportional to said intensity.

Abstract: Methods for uniformly distributing a flowing medium to a surface such as that of a rotary liquid permeable roll are disclosed where the flowing medium is distributed by a number of distribution units, the method including distributing the flowing medium to each of the distribution units and separately controlling the flow of the flowing medium to each of the distribution units whereby a uniform flow and an equal amount of the flowing medium is obtained in each of the distribution units. Distribution devices for uniformly distributing a flowing medium to such a surface are also disclosed.

Abstract: Adjusting the operation of a wire section, in which the development of the consistency of stock on the wire section (2) is determined and the effect of the consistency determined above on the formation and/or porosity of a paper web (3) is determined. The consistency developed on the wire section is adjusted based on a quality property of paper and/or by optimising a cost function, the quality property of paper comprising the formation and/or the porosity and/or a combination defined by means of the formation and/or the porosity and the cost function including the effect of at least the formation and/or the porosity.

Abstract: A system for feeding fibres from a fibre separation step at a first pressure to a drying step at a second, lower pressure, the system comprising a sluice feeder (3) provided between the fibre separation step and the drying step. At least an outlet (14) of the sluice feeder (3) is enclosed by a housing (4) for pressurization by means of a pressure medium in the housing (4) to a pressure that essentially corresponds to the first pressure in the sluice feeder (3). The fed out fibre from the sluice feeder (3) to the housing (4) are removable by means of the pressure medium in the housing (4) via a control valve (20), which regulates the pressure in the housing (4), to the drying step at the second, lower pressure. The pressurization in the housing (4) prevents steam to escape from the sluice feeder (3).

Abstract: The invention relates to an arrangement for controlling the edge of pulp mass in a web former, the web former comprising a space formed by two wires or the like, into which space the pulp mass is fed. The wires or the like are supported on a chamber units, which each time include at least one chamber for receiving the water removed from the pulp mass. In conjunction with the side edge of the said web former are arranged pulp mass edge control means, which include an edge sealing part. The edge sealing part extends, in the lateral direction of the web former, by a distance between the chamber units in such a way that it will prevent the pulp mass edge from passing and/or spreading in the lateral direction of the web former into the area of the said edge of the web former. The invention also relates to a method for controlling the pulp mass edge in a web former.

Abstract: A headbox (10) of a paper machine or such includes a bypass manifold (J1), from which the pulp is conducted by way of pipes (11a1.1, 11a1.2 . . . 11a2.1, 11a2.2 . . . ) of pipe rows in a set of pipes (11) and an intermediate chamber (E) into a turbulence generator (12), or from the bypass manifold (J1) directly into the turbulence generator and by way of the pipes (12a1.1, 12a1.2, . . . ; 12a2.1, 12a2.2 . . . ) of the turbulence generator's (12) pipe rows into a lip cone (K) and further out from the headbox on to a formation wire. The turbulence generator (12) of the headbox includes a fluidization element (14), wherein fluidization is carried out in one stage only and in which structure as little disturbance as possible is then caused to the fluidised flow.

Abstract: In a paper machine which comprises process elements and a measuring beam, the measuring beam is arranged at least at one paper machine process element so that a measuring device for measuring quality properties of a paper web is arrangeable in the measuring beam. The paper machine process element is e.g. a blow box, which is arrangeable in a dryer unit of the paper machine between drying cylinders to blow air via at least one blow air channel provided in the blow box to guide the moving paper web and/or to assist drying.

Abstract: The present invention provides a method making stratified paper by redistributing the pulp suspension inside the headbox nozzle using acoustic radiation waves. Acoustic radiation forces fractionate fibers based on fiber radius. The acoustic radiation waves separate the fibers by pushing the coarse and longer fibers to the inner area while fines and smaller fibers remain in the outer area. This has a similar effect of multi-layer stratification headbox, and provides paper with a smoother surface.

Abstract: A method for producing and testing a fiber bed, includes a housing, a main inlet passage and a main outlet passage, a cavity in the housing in fluid connection with the inlet and outlet passages, a body rotatably arranged in the cavity, the body being arranged with a through-going passage having first and a second opening, a screen arranged in the through-going passage, and elements for measuring properties of the fiber bed. The method includes positioning the body so that the first opening is connected to the main inlet and the second opening is connected to the main outlet, creating a first passage, leading a fiber suspension through the first passage in order to produce a fiber bed on the screen, measuring the properties of the bed, rotating the body such that the second opening is connected to the main inlet and the first opening is connected to the main outlet and creating a flow through the first passage for removing the fiber bed from the screen through the outlet.

Abstract: A method for fluidisation of a pulp flow in the headbox of a paper machine or such. The characteristics of the pulp flow are affected in the headbox's fluidiser (14) in one step only, whereby the height (h1) of the step is at least equal to the average fibre length, and after the fluidiser (14) the biggest permissible step expression in the flow channel in direction z is smaller than the average fibre length.

Abstract: In a paper or board machine, the cross-direction profile of a flow channel defined between a first dewatering element (52, 53) situated inside a first forming wire loop (50) and a second dewatering element (64, 65) situated inside a second forming wire loop (60) is measured, and the location and/or the position of the blade element (64, 65) is adjusted based on the measurement result in order to regulate the thickness profile of a stock flow. The measurement can be by passing an alternating current of low frequency to a current rail situated in the second dewatering element (64, 65) and by measuring the strength of the magnetic field created by it by at least two measuring devices which have been placed either in the first dewatering element (53) or, when the first dewatering element is a forming roll (52), in the same dewatering element (64) as the current rail.

Abstract: Methods for uniformly distributing a flowing medium to a surface such as that of a rotary liquid permeable roll are disclosed where the flowing medium is distributed by a number of distribution units, the method including distributing the flowing medium to each of the distribution units and separately controlling the flow of the flowing medium to each of the distribution units whereby a uniform flow and an equal amount of the flowing medium is obtained in each of the distribution units. Distribution devices for uniformly distributing a flowing medium to such a surface are also disclosed.

Abstract: A method and an apparatus for mixing dilution liquid into a stock flow in a paper or board machine. Dilution is carried out in at least two stages using in the first dilution stage (I) valves (V1, V2, V3 . . . ) fitted with a larger mutual spacing at different points of width across a headbox and passing the dilution water through the valves to desired points of width of the headbox according to the requirement of control of the basis weight of paper or board. In the second dilution stage (II), dilution water is passed into connection with the stock flow coming from the first dilution stage (I), said dilution water being controlled by means of valves (V1′, V2′ . . . ), which valves (V1′, V2′ . . . ) have been fitted with a denser spacing than the valves (V1, V2, V3 . . . ) of the first dilution stage (I).

Abstract: Process and apparatus for manufacturing a fibrous material web. The apparatus includes an automatic formation regulator, and the process includes on-line measuring of formation of the fibrous material web, utilizing the on-line measured formation as a controlled variable, and maintaining the formation at a preselectable target level via the automatic formation regulator.

Abstract: A paper/board machine headbox (10) has a stock inlet header (J), a tube bank (11), a turbulence generator (13) and a slice opening (14) which is provided with a profile bar. The headbox (10) is provided with cross direction measuring sensors (D1, D2; Dmn), by means of which the flow rate profile of the headbox (10) is determined, and the profile bar of the slice opening (14) of the headbox (10) is adjusted in the cross direction on the basis of the thus determined flow rate profile. The headbox (10) is provided with measuring sensors (D1, D2; Dmn) for determining the cross direction flow rate profile of the headbox (10) and with means for adjusting the profile bar on the basis of the flow rate profile.

Abstract: A system for feeding fibres from a fibre separation step at a first pressure to a drying step at a second, lower pressure, the system comprising a sluice feeder (3) provided between the fibre separation step and the drying step. At least an outlet (14) of the sluice feeder (3) is enclosed by a housing (4) for pressurization by means of a pressure medium in the housing (4) to a pressure that essentially corresponds to the first pressure in the sluice feeder (3). The fed out fibre from the sluice feeder (3) to the housing (4) are removable by means of the pressure medium in the housing (4) via a control valve (20), which regulates the pressure in the housing (4), to the drying step at the second, lower pressure. The pressurization in the housing (4) prevents steam to escape from the sluice feeder (3).

Abstract: The present invention relates to a method and apparatus for controlling the operation of an approach system of a paper machine or the like web formation apparatus. Especially preferably the method of controlling the operation of an approach system according to the invention is applicable to be used in connection with paper and paperboard machines as well as in connection with various apparatuses performing non-woven webformating.

Abstract: System and method of operating a machine for manufacturing and/or refining a material web wherein the machine includes at least one machine section. The method includes arranging a plurality of measurement zones in series along a process direction and detecting data in a region of the at least one machine section via at least one measurement zone of the plurality of measurement zones. The data concerns at least one measured parameter relating to the manufacture or refinement of the material web. The system includes a plurality of measurement zones arranged in series along a process direction of the machine. At least one of the plurality of measurement zones is located in the at least one machine section. At least one measurement device for detecting data is located in at least one of the plurality of measurement zones. An evaluation unit is provided for evaluating the data.

Abstract: Headbox transient responses for sheet weight and moisture are modeled as a combination of two sets of time constants and dead time delays. One set represents a shorter delay with faster response dynamics, the fast mode weight and moisture responses, and the other models the longer delay with slower dynamics, the slow mode weight and moisture responses. A weight and/or moisture transient model is then formed for headbox changes by combining the fast mode weight and moisture responses and the slow mode weight and moisture responses. Stock weight and moisture dynamic and delay time models are determined for operation of stock flow of the paper making machine and the stock flow is controlled in accordance with the stock weight and/or moisture models and the headbox weight transient and/or moisture transient model to compensate for weight and moisture changes in a web of paper being manufacture which weight and moisture changes result from headbox changes.

Abstract: The invention concerns a method for fluidisation of a pulp flow in the headbox of a paper machine or such. The characteristics of the pulp flow are affected in the headbox's fluidiser (14) in one step only, whereby the height (h1) of the step is at least equal to the average fibre length, and after the fluidiser (14) the biggest permissible step expansion in the flow channel in direction z is smaller than the average fibre length.

Abstract: An apparatus for dosing a liquid in manufacturing paper products, the apparatus comprising: a mixed fluid conduit carrying a mixed fluid to be directed to an application station, at least a portion of the mixed fluid being a starch material from a starch material source; a starch material source feeding starch within a starch material supply line to the mixed fluid conduit; a resin source feeding resin within a resin supply line to the mixed fluid conduit; and, a mixing section of the mixed fluid conduit dispersing the resin throughout the starch material. The apparatus may also include: a tank for receiving the mixed fluid; a supply conduit for delivering the mixed fluid to an application station; and, a return conduit for delivering the mixed fluid back to the tank from the application station.

Abstract: A headbox (10) has a stock inlet header, a tube bank, a tubulence generator and a slice channel. Measurement targets (PA, PB, PC, P, PE) are provided with means for making measurements of the fiber mobility of the fiber suspension, then controlling the flow state of the suspension. Sensors on the width of the headbox (10) or traversing sensors are positioned on different width points of the headbox (10) and arranged to measure the fiber mobility profile, with means for changing the flow state on the basis of the measurements. Apparatus for diluting the thick stock into headbox consistency and units for cleaning the stock to be fed into the headbox may be provided. Sensors may be disposed in the short circulation pipes or cleaning units arranged to measure the fiber mobility of the fiber suspension with means for changing the flow state on the basis of the measurement data.

Abstract: A multi-layer headbox for a paper or board machine including stock inlet headers each providing one stock and coupled to a tube bank which in turn is coupled to a respective intermediate chamber. The stock flows from the intermediate chambers into a turbulence generator and through pipes in the turbulence generator into a slice cone to be discharged therefrom onto a forming wire. The multi-layer headbox includes distribution valves for regulating the flow of dilution water across the width of the headbox. Each distribution valve communicates with a distribution plate placed in connection with the tube bank. From each valve, the dilution liquid is distributed at the same time to all the stocks that form the different layers of the web in the multi-layer headbox at a specific position of width of the multi-layer headbox.

Abstract: Process and a device for detecting a change in the fiber orientation cross-direction profile of a paper or cardboard web in the manufacturing process on a paper or cardboard machine. It is recognized that a change in the fiber orientation cross-direction profile in the web is inferred or determined by way of a characteristic change in the basis weight cross-direction profile or at least one measurement quantity that correlates to it, and/or by way of a characteristic change in the basis weight in the travel direction of the web or at least one measurement quantity that correlates to it. The device includes an arrangement for detecting a change in the basis weight cross-direction profile and/or a characteristic chronological course of the change in the basis weight, which is characteristic for a change in the fiber orientation.

Abstract: Method and apparatus for controlling the mixing proportions of feed streams being supplied to a headbox, using devices for sampling two or more of the feed streams upstream of the headbox and devices for measuring concentration of constituents in or other properties of those samples. A method of regulating one or more properties of a moving web, and especially a paper web during manufacture, employing the aforesaid method and apparatus are also disclosed.

Abstract: The stock approach piping to a multi-layered headbox can be modified to include a dilution water header that independently supplies dilution water, such as whitewater, to multiple CD segments or zones of the tube bank which supply stock to each layer. The CD basis weight profile of the final sheet is monitored and, in response to the measured CD profile, dilution water flow is increased or decreased to those tube bank segments that need their consistency altered. By selectively controlling the basis weight of distinct segments of the CD profile for each layer, a more uniform sheet can be produced.

Abstract: The invention concerns a headbox for a paper/board machine by whose means the basis weight of the web can be regulated. The headbox comprises a stock inlet header (Jl), which becomes narrower towards its end. Tubes (11a1, 11a2 . . . ) in a tube bank (11) open in the stock inlet header (J1) across the machine width, which tubes are connected with thickening elements (12a1, 12a2 . . . ) across the machine width, in which connection a flow (L1) is removed from the thickening element into the duct (D1) and said flow (L1) to be removed is regulated by means of a valve (V1, V2 . . . ). From the thickening element (12a1, 12a2 . . . ) a tube (14a1, 14a2 . . . ) for a flow (L2) of higher consistency is provided, which flow is passed further in the headbox.

Abstract: Control equipment for the headbox tip lath of a paper machine includes first actuators (12a1, 12a2 . . . ), which are located at different points along the headbox (100) width and connect functionally with a bendable intermediate part (14). At the different points along the headbox (100) width there are also second actuators (13a1, 13a2 . . . ) which are used in the tip lath control. These connect functionally with both the bendable intermediate part (14) and the tip lath (11). The first actuators (12a1, 12a2 . . . ) are used to perform rough control of the tip lath (11) whereas the second actuators (13a1, 13a2 . . . ) are used to perform fine control of the tip lath (11).

Abstract: The invention relates to a headbox (10) for a paper/boardmaking machine. The headbox (10) including a stock flow header (11) and, following the stock flow header, a piping system such as an inlet pipe manifold, and/or a turbulence generator (14) and a tapered slice (15), wherefrom the stock is passed onto the forming wire (H1). The construction of said headbox further includes a flow header (J) for a dilution liquid the flow header having connected thereto an inlet channel (S1), a return pipe (S2) and outlet channels (D1, D2, D3, . . . ) that are distributed over the full length of said flow channel for passing the dilution water to control valves (V1, V2, . . . ) and, therefrom, further to different points along the cross-machine width of the headbox so as to mix with the stock delivered from the stock flow header (11) in order to control the consistency of the stock to a desired value, thus accomplishing the control of the web basis weight profile in cross-machine direction over the headbox.

Abstract: Paper or cardboard machine and method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The paper or cardboard machine includes at least one headbox that extends across a machine width. The at least one headbox is adapted to provide a machine-wide distribution of a material suspension onto one of a screen and between two screens. The machine also includes at least one material suspension supply coupled to the at least one headbox and adapted to supply a material suspension to the at least one headbox. The at least one material suspension supply has at least one concentration.

Abstract: Controlling the velocity of a jet of foamed furnish leaving the slice of a pressurized headbox of a paper or a tissue making machine by measuring the density and pressure of a flow of foamed furnish provided by a pump to estimate an atmospheric pressure air content, measuring the pressure of the foamed furnish in the headbox, using the estimated atmospheric pressure air content and the measured pressure in the headbox to estimate the current velocity of said jet of foamed furnish, comparing the estimated current velocity with a target velocity and controlling the pump to move the estimated and target velocities closer to each other. An alternate embodiment controls jet velocity on the basis of comparing estimated and target headbox pressures.

Abstract: Method and apparatus for controlling the mixing proportions of feed streams being supplied to a headbox, using devices for sampling two or more of the feed streams upstream of the headbox and devices for measuring concentration of constituents in or other properties of those samples. A method of regulating one or more properties of a moving web, and especially a paper web during manufacture, employing the aforesaid method and apparatus are also disclosed.

Abstract: The invention relates to a method and equipment for controlling properties of paper, in which method the effect of the flow of retention agent (Fra) and the stock flow (Fts) on the basis weight of the paper (BW) is modelled. The fulfilled modelling is used to adjust the basis weight of the paper (BW) by controlling simultaneously the flow of retention agent (Fra) and the stock flow (Fts).

Abstract: A feedback-connected on-line regulation system for a headbox of a paper or board machine. The headbox includes a flow duct for stock suspension or separate flow ducts placed one above the other, each flow duct extending from an inlet header of the headbox into its slice channel. A stock suspension jet is discharged from the slice opening of the slice channel onto the forming wire or into the forming gap formed between forming wires. The regulation system includes a regulator unit and a set value unit. Measurement values are passed from the headbox system to the regulator unit and from the regulator unit, control values are obtained for controlling the actuators of the headbox system. The regulation system also includes an on-line If arrangement for measurement of the dried paper web or the paper web to be dried, and includes measurement of the distribution of fibers in the plane of the paper web.

Abstract: The invention relates to a method and equipment for controlling properties of paper, which method comprises modelling the effect of the flow of retention agent (Fra) both on the amount of filler in the white water and on the paper ash content (ASH), and the effect of the flow of filler (Ffi) both on the paper ash content (ASH) and on the amount of filler in the white water. The fulfilled modelling is used to adjust the amount of filler in the white water and the paper ash content (ASH) by controlling simultaneously the flow of retention agent (Fra) and the flow of filler (Ffi).