Abstract: Method and apparatus are presented for use in a papermaking process for determining permeability and/or compressibility characteristics of a pulp suspension within the process. The method/apparatus includes monitoring height of pulp suspension within one or more test columns as a function of time while allowing pulp suspension drainage from each test column. At least one parameter representative of permeability or compressibility of the pulp suspension is determined, via computer processing, using the monitored height as a function of time of the pulp suspension within the test column. The at least one parameter representative of permeability or compressibility can comprise specific surface area (S.sub.w), specific volume (v.sub.f) compressibility constant m or compressibility constant n for the pulp suspension.

Abstract: Apparatus and process for controlling the basis weight of paper produced in a papermaking machine are provided. In the papermaking process, a major portion of the paper stock flows through a first line that is controlled by a thick stock valve and a minor portion of the stock flow from the stuff box to the headbox is diverted through a second line that is regulated by a second valve (e.g., vernier valve). The thick stock valve is controlled by the dry end basis weight and the second valve responsive to measurements of the basis weight of the wet stock at the wire. The second line and control valve along with the wet end basis weight measurements form a fine control loop with fast response time whereas the first line and control valve that is responsive to dry end basis weight measurements form a course control loop. The dual control loops enable fast and actual basis weight control.

Abstract: A system and method that combine an array of fast under wire water weigh sensors with a scanning system provides an accurate measurement of the entire sheet down to 1 in. by 1 in. resolution. Because CD profiles are obtained instantaneously, MD and CD variations are completely decoupled, even if CD profiles are taken at longer intervals apart.

Abstract: A method of determining the filler content of paper, wherein the paper stock is examined prior to delivering the stock to the de-watering section of the paper machine, and wherein the volume concentration of particles in the stock that have a size which is greater than the characteristic size of the filler is determined at varying mechanical working of the pulp, and the amount of filler retained in the paper is predicted from the result of at least two such determinations.

Abstract: The invention relates to a method and an equipment for defining the cross-directional properties of a sheet in a continuous sheet making process. According to the invention, the set point profile of the actuators affecting the cross-directional properties of the sheet is defined, high frequencies are filtered from the defined profile, and shrinkage nonlinearity is deduced from the filtered profile without modulating or stimulating the actuators.

Abstract: A system and method of producing a paper product from a wetstock solution using a sensor for sensing resistive impedance changes of the wetstock on the support web of the system. The resistive impedance changes are used to measure physical characteristics such as water weight of the wetstock on the support web of a sheetmaking system. The system includes a fixed impedance element coupled in series with a sensor portion between an input signal and ground. The sensor portion is an electrode configuration which includes at least two electrodes with a portion of the wetstock residing between and in close proximity to the electrodes. The sensor exhibits a variable impedance resulting from changes in the physical characteristics of the wetstock.

Abstract: In a paper-making machine, a method of determining a volumetric percentage of air in a fiber suspension for delivery to a headbox. The fiber suspension is transported through a fluid conduit. A sound transmitter and a target receiver are positioned relative to the fluid conduit. A sound is transmitted through the fiber suspension from the sound transmitter to the target receiver. A speed of the transmitted sound from the sound transmitter to the target receiver is established. The volumetric percentage of air in the fiber suspension is determined, dependent upon the established speed of sound.

Abstract: The present invention is directed to a method for controlling and adjusting the permeability of a cigarette wrapping paper. Permeability is controlled in the paper by adding different sized filler particles in different proportionate amounts. Permeability of the paper is altered without having to change the total amount of filler in the paper. By selectively controlling the permeability of the paper, various characteristics and properties of a cigarette made with the paper can be likewise modified as desired. In one embodiment of the present invention, the permeability of a cigarette wrapper can be automatically maintained or adjusted as the paper is being made.

Abstract: A method of stabilizing a low strength sheet which involves passing the sheet under an apparatus having a width and a top surface and moving in a first direction at a rate sufficient to entrain air. The apparatus includes an airfoil adapted to extend along the top surface of the sheet. The airfoil, in turn, includes:a bottom surface adapted to extend along a portion of the top surface of the sheet;a first surface extending a first distance from the bottom surface at a first juncture;a second surface extending a second distance from the bottom surface at a second juncture; anda top surface extending from the first surface at a third juncture to the second surface at a fourth juncture. The first distance in general is less than the second distance.

Abstract: A headbox for a papermaking machine with an outlet slot that distributes pulp suspension over the, working width of the papermaking machine. For controlling operating parameters of throughput, pulp density and fiber quality of the suspension over the width of the machine, the headbox has a plurality of individual sections across the width of the machine. Each section has respective channels therethrough for passing pulp suspension. At least one connection at each section is to a controllable supply of pulp suspension where the operating parameters of that supply are controllable. Only separate operating parameter controlled streams pass through the sections of the headbox. Operating parameter control devices may deliver adjusted streams to a mixer upstream of the headbox channels. The mixer may also have individual sections across the width of the machine.

Abstract: Procedure for the drainage of the wire and/or press section of a paper machine, in which procedure at least one suction pipe (1) is provided with at least one gap (2) and the suction pipe (1) is connected to a vacuum device (4) to develop a vacuum at least in this vacuum pipe, and in which procedure a felt, wire or equivalent (3) is moved over the gap of the suction pipe, water being thus drained from the felt, wire or equivalent. In the procedure, the vacuum capacity is adjusted by measuring and/or adjusting at least the amount of water drained from the suction pipe (1) and, on the basis of the measured data, adjusting the vacuum capacity by means of regulating devices (11, 12). The invention also relates to an apparatus for adjusting the vacuum capacity.

Abstract: A method of predicting the dry stock weight of paper that is produced by a papermaking machine based on simultaneousness measurements of (1) the water weight of the paper stock on the fabric or wire of the papermaking machine and of (2) the dry stock weight of the paper product is provided. The invention which provides a linearized model of the de-watering process is based in part on that creation of drainage characteristic curves that provides an effective means of predicting the drainage behavior of the paper stock on the fabric of a de-watering system.

Abstract: The headbox apparatus of this invention contributes to the production of a paper web of uniform fiber orientation by controlling the edge flow of stock into the headbox nozzle through adjustable valves positioned in edge tubes in closed loop with a fiber orientation sensor. At the same time that fiber orientation is being control through adjustable valves position in the edge tube, basis weight of the web being formed is controlled by a stock dilution systems and an adjustable slice lip, in closed loop with a basis weight profiler sensor.

Abstract: A method for regulation of the transverse distribution of the fiber orientation of a web produced by means of a paper machine or equivalent, by regulating the transverse profile of the discharge opening (16) of the headbox (10) of the paper machine. The transverse grammage profile of the paper web (W.sub.0 . . . W.sub.1) produced by means of the paper machine is measured, and the measurement signal obtained in this way is used as a feedback signal in the control system. With the machine configuration and parameters present in the paper machine to be controlled, data are collected concerning the relationship between the directional angle of the transverse distribution of fiber orientation and the transverse distribution of grammage of the web (W.sub.0 . . . W.sub.1) that is being produced by, carrying out response runs of the paper machine in its various states of operation (i). The relation data are stored in the memory of the computer (52).

Abstract: A roll and blade gap former for a paper machine having first and second wires guided in a respective loop and defining a twin-wire forming zone, a forming gap in which the first and second wires converge before the twin-wire zone, a headbox including a slice channel having a slice opening through which a stock suspension jet is fed into the forming gap to form a web between the wires, and drainage and forming elements arranged in the twin-wire zone for removing water from the web. To provide an improvement in the control of the Z-direction properties of the web, the former includes turbulence generating vanes arranged in the slice channel in the headbox to cause turbulence in the stock suspension jet upon its discharge from the slice opening into the forming gap and a first forming roll arranged in the twin-wire zone and which constitutes the first drainage and forming elements in the twin-wire zone after the forming gap.

Abstract: Process for damping pressure pulsations and apparatus for performing the process. The process of this invention serves for the damping of pressure pulsations in a fluid, particularly a fiber suspension, flowing in a closed system wherein the pressure pulsations to be damped are measured at a measuring site and compensated at a correction site, with a throttle position being located between the measuring and the correction sites, with the damping of the imparted pressure impulses occurring at the correction site, which pressure impulses are opposite to the measured pressure pulsations, with the time periods thereof being about the same as those of the measured pressure pulsations. Several apparatuses for performing the process are also set forth.

Abstract: A method and system of measuring deflected doctor blade angle and loading force of an arrangement including a doctor apparatus operating in connection with a rotating cylinder, the apparatus having a doctor blade and a support member which pivots about at least one pivot point in response to an externally applied force for applying the doctor blade to a contact point on the cylinder. The arrangement corresponds to a kinematic model of linkages including a first link defined between the at least one pivot point and the contact point, a second link defined between the contact point and the center of the cylinder, and a third link defined between the center of the cylinder and the at least one pivot point.

Abstract: An endless loop of fabric of the type used in papermaking is provided with a row of optically detectable marks aligned in the direction of motion of the fabric. A beam of light pulses from a strobe light is directed to a position on the fabric through which the row of marks passes and the position of the marks as illuminated by the strobe light is observed. When the observed marks are stationary, the speed of the fabric can be determined based on the frequency of the light pulses from the strobe light and the spacing between the marks on the fabric. The speed of the fabric can be controlled to a desired speed by setting the strobe pulse frequency and adjusting a variable speed drive for the motor driven rollers driving the fabric until the marks as illuminated by the strobe light appear stationary. Variations in the speed of the fabric result in variations of the position of the marks as illuminated by the strobe light, allowing equipment problems causing the speed variations to be diagnosed.

Abstract: The invention is directed to a paper machine including a headbox having an inlet and an outlet. A fluid conduit is connected to the inlet of the headbox. A sensor is disposed in communication with an interior of the headbox. The sensor senses a pressure of the fiber suspension within the headbox and provides a signal corresponding thereto. A first pump is connected to the fluid conduit and supplies a fiber suspension to the headbox through the fluid conduit. A second pump is connected to the fluid conduit between the first pump and the headbox, and further is connected to the sensor. The second pump is a substantially pulseless pump, and transports the fiber suspension away from the fluid conduit, dependent upon the sensed signal.

Abstract: A process control method for adjusting chemical application in response to the pulp brightness and/or lignin content is realized by utilizing a coupled control feedforward, feedback or combination feedforward/feedback control system, wherein brightness measurements are made between successive lignin content measurements and adjustments made to the chemical application in response to a comparison value.

Abstract: The invention relates to an apparatus for detecting plugged sites and holes and for measuring of the water permeability properties of pervious machine fabrics. Plugged sites in a permeable fabric are detected by sensing water pressure pulses occurring in the nozzle at the moment when a stream of water flowing through the nozzle contacts a plugged site on a fast running fabric. The apparatus can be used on-line to simultaneously detect plugged sites and holes on a moving pervious fabric while monitoring its water permeability properties.

Abstract: A method and apparatus for processing a longitudinally traveling web of material using a sheet treating device positioned in a transverse direction relative to the web. The sheet treating device having a plurality of individually controllable zones for controlling a target parameter of the web, for example, the thickness, bulk, dampness, smoothness or sheen of the web. In conjunction with the sheetmaking device, a measuring instrument for measuring an actual value of the target parameter is placed downstream of the sheet treating device. An actual profile that is determined by the actual values is compared with a desired profile, and the zones of the sheet treating device are adjusted such that the discrepancies between the two profiles are minimized. To improve the matching of the actual profile to the desired profile even further, the web and/or the sheet treating device are shifted relative to the other in the transverse direction to minimize the discrepancies between the two profiles.

Abstract: This invention relates to an apparatus and method for identifying periodic roughness variations on a paper surface. Such devices of this type, generally, collect topography data from the paper surface, analyze the data, and compare the data with known signature topographies of paper machine clothing and equipment to determine the location in the paper manufacturing process where the periodic roughness variations on the paper surface are being produced.

Abstract: A method for determining the cross-machine shrinkage or expansion profile of a travelling sheet produced in a sheetmaking machine between an upstream location and a downstream location. The method involves marking the sheet at the upstream location with an array of marks at measured, predetermined intervals in the cross-machine direction. The sheet is inspected in the cross-machine direction at the downstream location to measure the spacing of the array of marks. A shrinkage or expansion profile of the travelling sheet is developed based on the changes in the spacing between the array of marks at the downstream location. Apparatus for carrying out the method is also disclosed. The method and apparatus of the present invention permit rapid and precise determination of the sheet shrinkage or expansion profile to allow for better control of property variation across the sheet.

Abstract: An apparatus and method for treating a sheet material (3) with an arrangement of rollers (6, 7), including at least one heated roller (8, 9), which defines at least one roller gap through which the sheet of material is passed and acted upon with pressure and/or elevated temperature. A housing (32) surrounds the roller arrangement (6, 7) and the treatment takes place in an environmental atmosphere, the temperature and/or humidity of which can be adjusted to a specified value. A roll of the sheet material is subjected to pretreatment to provide it with desired temperature and humidity conditions before entering the housing (32).

Abstract: A sampling device for a batch or continuous pulp digester for reduction of pulp sampling errors such as during a digester "blow" and for improving a pulping process based on the obtained samples.

Abstract: A mill for the processing and production of wood pulp is contained substantially entirely within a single, integral structure that defines a unitarily-covered space substantially bounding and enclosing the mill. The mill includes a main control room or station for overall monitoring and control of pulp processing operations in the mill, the main control station being disposed substantially centrally within the covered space, and a plurality of processing stations at which various pulp processing operations take place in a generally sequential manner or order.

Abstract: A process and apparatus for controlling and/or regulating a solids-liquid separation process, such as in a dewatering or drying device includes at least two photodetectors, each associated with a light source, a detector to detect light of the associated light source reflected from the surface of the solids-liquid mass, a controller generating an output signal as a function of the detected light and converting and processing the output signals of the photodetectors into correcting variables for controlling and/or regulating at least one process parameter of the separation process. At least one of the photodetectors is associated with at least one second photodetector for detecting light reflected into the photodetector at an angle, preferably an angle of 30.degree. to the main direction of reflection. The output signals of the photodetectors are advantageously processed into correcting variables for the step-wise adjustment of the at least one process parameter to optimize the separation process.

Abstract: This invention relates to the measurement and control of consistency in an aqueous flow stream, as it leaves a stage (i.e. Bleaching Stage) of the papermaking process. More particularly, the present invention relates to the measurement used for control of wood fiber and suspended solids in a papermaking pulp stock flow stream.

Abstract: A method and apparatus for lateral alignment of a cross-direction profile control of a web as required in a paper-making process. In the method, a certain cross-direction profile of a dried web, particularly the basis weight profile thereof, to be aligned is gauged. A profile measurement signal thus obtained is passed to a control system of the paper machine which provides a control signal suited to control adjustment devices of the cross-direction profile control provision. The web is provided with at least one marker line whose lateral shift or shifts is/are detected at the measurement point of the cross-direction profile of the dried web, or in the vicinity thereof. The detection of the lateral shift(s) is used to generate a measurement signal thereof which is employed to control the lateral alignment of the web profile adjustment provision.

Abstract: An apparatus and method for monitoring the de-watering performance of a forming section of a papermaking machine is disclosed which includes a laser instrument having a laser displacement meter laterally spaced and supported above an upper run of a paper forming fabric having a paper stock deposited thereon. A head box deposits paper stock consisting of a water/fiber mixture on top of the upper run. An adjustable C-shaped carrier stand has an upper leg that supports the laser instrument above the upper run of the forming fabric. The carrier stand has a lower leg to support a baseline contact device below the upper run of the forming fabric. The laser displacement meter is disposed at a laser reference position above the forming fabric so that a laser beam is reflected off of the paper stock which is deposited on top of the forming fabric.

Abstract: The invention relates to a method and apparatus for cutting the edge of a fibre web (4) in a paper machine. In the method, water nozzles (13a, 13b) are Conducted in a transverse direction with respect to the edge of the fibre web (4) so that the place where the cut comes against the surface of the yankee cylinder of the drying unit varies. The apparatus comprises water nozzles (13a, 13b) used for cutting, pipes (14a, 14b), a base (16), and a pneumatic cylinder (17) by which the water nozzles (13a, 13b) are deflected both in a longitudinal and transverse direction with respect to the fibre web (4).

Abstract: The release of a crepe paper web (1) from a Yankee-cylinder (4) is carried out with the aid of a doctor blade (5). The web is taken up on a roll (9) under a specific degree of creping. The paper web has a web-part which is drawn freely between the doctor blade and the roll, and with the aid of a device (11, 12) which functions to deliver a substance between the paper web and the Yankee-cylinder for controlling web release. A deformation force is exerted (via 20) on the paper web at a local part of the freely drawn web-part. The resultant positional change at that local web-part is detected so as to obtain an electric signal corresponding to the tension in the paper web. That signal is passed to a control unit (13) for controlling the supply of substance to control release of the paper web from the Yankee-cylinder.

Abstract: A method of reducing surface irregularities in paper machine headbox components such as the apron floor. A lap having a working surface diameter greater than the dominant dimensional characteristic of the irregularities is provided. The lap's working surface is machined flat to a tolerance equivalent to a desired flatness tolerance of the apron floor. A central, circular portion of the lap's working surface is counterbored to define an outer, annular cutting region on the lap's working surface. The apron floor is levelly supported and measured to obtain an initial profile of surface irregularity as a function of position on the apron floor. The lap is then driven to rotate its cutting region levelly on and over the apron floor while abrasive material in solid form and a coolant are applied between the lap and the apron floor. The apron floor is again measured to obtain an updated profile of surface irregularity as a function of position on the apron floor.

Abstract: An edge tracking apparatus for maintaining a continuous circulating papermaking fabric in an aligned position as it moves through a papermaking machine. The edge tracking apparatus includes a pivotally mounted guide roll and a laser scanner. The laser scanner, which produces a laser screen, is positioned relative to an edge of the papermaking fabric so that the edge bisects the laser screen. A controller is connected with the laser scanner. The controller acts to receive signals from the laser scanner in response to transverse movement of the edge of the papermaking fabric and to convert those signals into control signals which activate a drive in the steering apparatus. The drive shifts the longitudinal position of the guide roll causing it to steer the papermaking fabric back into its aligned position. A recording unit is also connected with the controller and is controlled to plot the position of the edge during operation of the papermaking machine.

Abstract: A method, device, and arrangement in a paper machine for regulating the control of the transverse profile or profiles of properties of a paper web produced therein. Water is removed from the paper web under compression between two forming wires by making use of dewatering and/or forming ribs. The deflection of the dewatering and/or forming ribs in the transverse direction of the web is regulated thereby affecting the retention profile of the paper web in the cross direction. By regulating the deflection of the dewatering and/or forming ribs, the transverse fiber-orientation profile and/or the filler profile of the paper web is influenced through the control of the transverse retention profile of the web.

Abstract: This invention relates to a method and apparatus for determining the wicking characteristics of a web, particularly a paperboard web with respect to a liquid. The apparatus comprises a web holder having an upper section, a lower section, an upper web seal attached to the upper section for sealing against a first surface of the web, a lower web seal attached to the lower section for sealing against a second surface of the web, and means for connecting the upper and lower sections together with the web disposed therebetween so the upper and lower seals sealingly engage the respective first and second surfaces of the web between the seals.

Abstract: An apparatus for detecting and determining the average value of the foreign materials contained in pulp suspension includes a pulp suspension introducing passage connected to a separating device including a primary chamber and a secondary chamber separated by a screen, the pulp components in the pulp suspension passage pass through the primary chamber, screen, and secondary chamber; a circulation passage connected between the primary chamber's inlet and outlet for circulating the pulp suspension containing the foreign materials in the primary chamber therethrough; and a device for detecting and determining the average value of the foreign materials contained in the circulated pulp suspension, the detecting device being located in the circulation passage.

Abstract: A plurality of spaced knock-off shower nozzles are located adjacent to an edge of a paper web forming wire to provide knock-off sprays which will remove trim strips from the wire. A control is provided to separately and independently control the spray nozzles so that the operator can adjust the number of nozzles being sprayed in accordance with the width of the trim strip.

Abstract: A doctor cooperates with the peripheral surface of a Yankee dryer for peeling the tissue away from the peripheral surface such that when the tissue is peeled from the surface, a series of microfolds are generated in the resultant tissue. An adjusting mechanism is connected to the doctor for adjusting an angle defined between the doctor and the peripheral surface. The arrangement is such that when the angle is adjusted, the physical dimensions of the microfolds change. A sensor is disposed downstream relative to the doctor for sensing the physical dimensions of the microfolds. A control circuit is electrically connected to the sensor and responsive to the sensor. The control circuit is electrically connected to the adjusting mechanism for varying the angle of the doctor so that the physical dimensions of the microfolds are optimized.

Abstract: A method and apparatus for detecting impurities in raw pulp slurry at high precision using samples on-line. The pulp slurry is passed through a flat mesh wire to accumulate pulp fiber on the wire surface and prepare a wet mat, after which the surface of the wet mat is detected by a CCD camera in a catoptric system while pressed against a flat transparent plate, and the image is processed to measure the area of impurities per unit area of the wet mat.

Abstract: A pulp furnish containing predominantly wood-containing fibers (mechanical) and natural calcium carbonate as a filler is formed into a paper in a paper forming section of a paper machine at a neutral pH in the range of 6.7 to 7.5. Bentonite plus a suitable polymer such as a polyacrylamide produces a pulp stock that has exceptionally high drainage characteristics particularly when used with chalk as the filler. The pH of the stock in the headbox is maintained at the desired level of pH 6.7-7.3 by monitoring the pH in the headbox and adjusting the flow of pH reducing and buffering agent, preferably phosphoric acid, into the pulp prior to the headbox to obtain the desired pH in the stock.

Abstract: The load on a refiner motor is controlled by adjusting the motor load setpoint by monitoring load applied by the refiner and the plate gap between the refiner plates to define the curve of the load versus plate gap relationship. This slope of load versus plate gap relationship is estimated and when the sign of the slope of the curve changes sign indicating operation in an unstable zone of pad collapse and based on the tendency for the refiner to be in the unstable operation zone over a selected period of time exceeding a preset limit adjusting the setpoint lower to approach more closely the maximum load applied over the selected time.

Abstract: An apparatus and method for measuring the de-watering performance of a forming section of a papermaking machine is disclosed which includes a laser instrument assembly having first and second laser displacement meters laterally spaced and supported above an upper run of a paper forming fabric. A head box deposits paper stock consisting of a water/fiber mixture on top of the upper run. An adjustable carrier stand supports the laser instrument assembly above the upper run of the forming fabric. The first laser displacement meter is disposed in a first position above the forming fabric so that a laser beam of the first laser meter is reflected off of the paper stock which is deposited on top of the forming fabric. The second laser displacement meter is disposed in a second position above said forming fabric so that a laser beam of the second laser displacement meter is reflected off of a bare edge of the forming fabric.

Abstract: Devices and methods for sensing the charge condition of a mixed stream of aggregant and aqueous dispersion of charged particles are based on sensing changes in the potential of an electrode contacting the stream. Sensing the changes in potential permits better control of aggregation in raw water and effluent treatments.

Abstract: The system effects an automatic observation of the dry line on wire of the Fourdrinier paper machine and the control actions based on it. In order to produce an image of the dry line range on wire this is illuminated by means of a large, diffusely illuminating surface (20) of even luminosity. The material on moving wire (10) is imaged by an optoelectric camera (40) on a detector whereby the pulp surface preceding the dry line and being specularly reflecting is found homogeneous and bright while the web surface following it and being diffusely reflecting is found homogeneous but matter and darker. The electric image signal delivered by the detector is conducted to a computer (50) in which the dry line is identified as the borderline of said surfaces of different brightness.

Abstract: The specification discloses an improved method for drying a paper or paperboard web emerging from the press section of a papermaking machine as it traverses a dryer unit. The method comprises continuously rewetting the web across its width during the initial web drying stage when the web has a solids content of no more than about 65 wt. %. The method improves the water removal rate and decreases the shrinkage rate of the web during drying.

Abstract: In general, the invention features method for regulating sulfur dioxide emissions from the recovery furnace of a Kraft paper mill.

Abstract: A system for aligning control zones with measurement zones in a sheetmaking system having a plurality of actuators arranged in the cross-direction, comprising the steps of: a) bumping at least one of the actuators; b) measuring a profile of the sheet at a substantial distance from the bumped actuators; and c) determining a location of the effect of each of the bumped actuators on the sheet.

Abstract: A formation control method and apparatus in which an image is emitted from a light source and transmitted through a predetermined area of paper an captured by a camera to be displayed as transmitted light image on a display of an image processing computing element, the transmitted light image displayed on the display being image-analyzed to obtain formation factor for quantification of the formation, J/W ratio and the like being optimized by fuzzy control using membership functions based on said formation factor so as to improve the formation.