Abstract: A method of controlling the properties of a paper web across the feed direction, i.e., cross profile, in a paper machine. The cross profile is adjusted in a plurality of setting positions across the web. Proceeding from a measured cross profile and desired cross profile, an optimum correction in the setting positions is calculated, so that the cross profile is brought into agreement with the desired one. At this calculation the circumstance is utilized, such that a disturbance in the stock in a certain setting position results in a corresponding change in the cross profile of the paper web.

Abstract: Complete definition of a papermachine headbox slice opening requires the measurement of three interdependent dimensions including (1) the projection distance of the slice lip edge below the slice beam, (2) the projection distance of the slice apron edge beyond the plane of the slice lip edge and (3) the slice opening distance between the slice lip edge and the upper face plane of the slice apron. A single gauging tool is provided for measuring all three headbox slice dimensions.

Abstract: A modified infra-red scanning gauge used in measuring the moisture content of a paper-web during manufacture or when subject to a coating practice, has a measurement channel and a reference channel. The measurement channel is based on the infra-red absorption spectrum of water which has an absorption band centered on 1.94 microns. The reference channel is conventionally at a wavelength of 1.83 microns where water has previously been considered to be transparent to infra-red or at a wavelength of 1.68 microns. The gauge is intended for measurement of high water content, where at 1.94 microns absorption effectively becomes total thereby preventing measurement being made, and uses a narrow-band filter of 0.03 micron wavelength offset from the peak of the 1.94 micron absorption band in the range 1.76 to 1.87 microns, previously considered stable as regards water content but now disclosed as showing a water-dependent variation at high water contents. In a specific example a 1.

Abstract: Method and apparatus for compensating bending of a lip beam in a paper machine when papermaking pulp flowing through the slice formed with the lip beam causes loading upon a bottom surface of the top lip beam. The bending of the beam caused by the loading is compensated by bending the lip beam in the opposite direction, by creating a temperature difference in the lip beam between a top part and a bottom part of the same.

Abstract: Fiberizer efficiency is improved by providing an inline control valve at the fiberizer feed inlet which automatically provides the fiberizer with make-up air proportional to the pressure differential between the fiberizer outlet and inlet. The make-up air tends to distribute the feed material more evenly within the feed inlet and provides a constant fiber/air ratio within the fiberizer.

Abstract: A device for measuring the moisture content and basic weight of paper in a gravimetric and more accurate manner than before. The device includes a cutting device for cutting the sample from a specimen sheet, a balance for weighing the sample, a computer for computing the moisture content and the basic weight of the sample, an output device for printing out the results of the moisture content and basic weight as well as a controller for controlling the device automatically and advantageously a drying device for drying the sample.

Abstract: In a papermaking or like operation wherein fibers are supplied to a headbox in a foamed furnish, a method of controlling furnish flow including the steps of controllably advancing the furnish along a flow path to the headbox, measuring the volume flow rate of furnish through a fixed cross-sectional area in the path with a magnetic flowmeter, combining the flow rate measurement at least with measured values of furnish density and pressure in the path and with a reference pressure value to obtain a corrected volume flow rate value, and controlling the advance of furnish in the path upon departure of this corrected value from a desired value so as to change the corrected value toward the desired value. A temperature measurement can also be combined with the other measured values, and with a reference temperature value, in obtaining the corrected flow rate value.

Abstract: A surge control system for dewatering press felts on a papermaking machine which includes a suction pipe, a variable speed drive motor, a centrifugal exhauster driven by the variable speed drive motor and connected to the suction pipe to provide vacuum to a felt passing over a slot for dewatering thereof. A surge valve is provided and is opened to admit air to the centrifugal exhauster so as to prevent surge when the centrifugal exhauster is operating at a predetermined level at which the centrifugal exhauster will surge.

Abstract: A method for controlling the addition of cationic additive materials to a paper mill slurry used to neutralize the anionic contaminants in a papermaking process is disclosed which utilizes total organic carbon measurements of samples of the slurry as an indicator of the cationic demand of the paper mill slurry. The method of the present invention discloses the discovery that measurements of the total organic carbon taken from filtered samples of the papermaking slurry correlate very well to cationic demand measurements of a papermaking slurry. Therfore, measurements of the total dissolved organic carbon content may be used to determine the desired addition rate of cationic additives in a more convenient and reliable manner than prior control measures. According to the method of the present invention, monitoring of the papermaking slurry by total organic carbon measurements as a cationic additive control parameter provides improved control of such factors as machine drainage and retention.

Abstract: A method for operably adjusting a leading strip of a forming board of papermaking wire wherein the position and length of an impinging papermaking slurry is detected and the length of the leading strip adjusted.

Abstract: A process is provided for controlling a thickness regulating member such as a slice lip coupled to slice rods. The process includes determining the desired configuration of the slice lip and determing the required slice rod movements based upon physical characteristics of the slice lip and the slice rods.

Abstract: A method of determining the properties of fiber pulp by separating a batch of a predetermined volume, by measuring its temperature, and by filtering water from it by means of a pressure difference. In accordance with the present invention, substantially all the water is filtered off from the pulp mixture, an air flow is produced through the filtered pulp cake by means of a pressure difference, the resisting effect of the pulp cake on the flow of air is measured, and the pulp cake is weighed, whereafter the properties of the pulp are calculated on the basis of the measurements, from mathematical models developed for this purpose.

Abstract: On-line apparatus for analyzing the formation of a moving web of paper, using a source of light directing a beam through the paper and a photodetector receiving the light which has passed through the paper, has a circuit preferably including a tunable band pass filter and demodulator producing a D.C. output reflecting size and distribution of flocs. The output gives similar results to those obtained by visual judgement of formation.

Abstract: The invention is a method for measuring fiber angle in a fibrous solid material relative to three mutually orthogonal reference axes. It is particularly well suited for measuring diving grain and grain surface angle in wood. The method is based on the measurement of the intensity of reflected light at different azimuthal angles when a beam of light of small diameter is impinged upon the surface. The nature of the specular reflections from a light beam striking the surface of a cylinder serves as a model for the system. A preferred apparatus for practicing the method comprises a light source, which may be a low powered laser, aimed normal to the surface of the fibrous material. A plurality of photosensors lying in a plane normal to the axis of the light beam are placed around the light source to detect the light reflected at various azimuthal angles. When the fibers of the material lie normal to the light beam, reflected light maxima are seen 180.degree.

Abstract: An ultrasonic echo sounding device permits observation of the web formation and/or the pulp suspension flow on the wire part and in the head box of a paper machine. The device includes a series of ultrasonic detectors connected to the wall of the flow channel in the head box and/or to the forming wire. The detectors direct an ultrasonic field at the pulp suspension layer, and the echo signals received from the pulp suspension layer are detected. The detectors operate as acoustic lenses so that the focal points thereof are located in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer in a manner whereby information concerning fibre bundles, air bubbles, variations in consistency, corresponding parameters and their variations in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer are indicated by the device.

Abstract: A method and apparatus for delivering a multilayer stock jet to a forming surface in a papermaking machine with a multilayer headbox having a slice chamber formed by side walls and top and bottom walls terminating in lip members defining a slice opening and at least one relatively rigid stock separating partition fixed at its upstream end and attached to the side walls at points downstream of and at a distance from said upstream end and dividing the slice chamber into separate slice channels through which separate papermaking stocks are fed by separate pumps and discharged through the slice opening to the forming surface, in which ultrasound distance measuring devices are used to detect any deviation of the partition from a straight line connecting the points of its attachment to the side walls of the slice chamber and at least one of the stock feeding pumps is controlled in response to any detected deviation to reduce the deviation to a negligible value.

Abstract: A method and apparatus for measuring a colloidal potential are described using pulses of ultrasonic energy that are directed along a path within a liquid suspension of colloidal particles. A vibration potential is measured at at least a pair of positions along the path. The positions are known relative to the source of ultrasonic pulses. The vibration potential measurements are then used to derive a colloidal potential which is independent of its attenuation encountered by the ultrasonic energy inside the suspension. In one embodiment several potential measuring probes are used and in another embodiment one probe is moved between predetermined positions.

Abstract: A vacuum control system and method for dewatering felts or fabrics on a papermaking machine including a suction pipe and a centrifugal exhauster connected to the suction pipe to supply a variable vacuum level. The fabric is passed over a slot in the suction pipe so that suction applied therethrough will dewater the fabric. A variable drive device is connected to the centrifugal exhauster for its operation with the variable drive device being responsive to an increase in the vacuum level in the suction pipe as fabric permeability decreases to correspondingly increase the speed of the centrifugal exhauster so as to increase the vacuum level in the suction pipe as a function of the decrease in felt permeability.

Abstract: The softness of paper as a function of the number of bonding sites per unit area of the paper is determined by directing ultrasonic energy toward the paper and determining the magnitude of the portion of reflected energy.

Abstract: The invention relates to a method and an apparatus for detecting and counteracting a deformation of the stock discharge gap in a paper machine headbox, which is caused by thermal expansion due to the temperature of the stock and/or the pressure of the stock. This is achieved by ultrasonic transducers located close to the slice opening which obtain measurement results relating to the distance between the roof member and the apron beam member of the headbox. At least two such transducers, one preferably located close to a side wall of the discharge gap and the other preferably located midway between the side walls, give information about a possible difference between the measurement results caused by the deformation. This difference serves as a guide for adjusting the temperature of the apron beam member and/or the roof member in such a way that the deformation is reduced in magnitude or entirely eliminated.

Abstract: A method and apparatus for obtaining information, during operation of a headbox for a paper machine, about the size, at one measuring point at least, of a stock discharge slot which is bounded by two structural members comprising two lip members of the headbox of two partitions arranged between the lip members or one of said lip members and one of said partitions. According to the invention, for every such desired information, an ultrasonic transducer means arranged at the measuring point in the headbox and with a combined transmitter and receiver for ultrasound is arranged to transmit an ultrasonic pulse through the stock between two of said structural members within predetermined surface areas of these located in proximity to said discharge slot.

Abstract: Method of paper tension control to maintain the frequency and amplitude of paper flutter. A noncontacting sensor means is mounted adjacent a portion of the paper path in a paper manufacturing apparatus. The sensor means detects flutter in a paper web travelling across the paper path. The tension in the paper web can be determined from the frequency and amplitude of the flutter. By adjusting the tension in the paper web to maintain the flutter within a predetermined range of frequency and amplitude, the tension in the paper web can be maintained at a desired level.

Abstract: A method is provided for controlling the moisture content of a paper web during its movement through the drying section of a paper making machine.According to the present invention it is possible to control or equalize the moisture profile of a fiber web, e.g. the paper web in a paper making machine, during its movement through the drying section of a paper making machine, so that the finished paper web will be provided with a desired moisture level and if desired a moisture profile as uniform as possible, wherein the paper web in the drying section of the machine being moved to contact with a means, the parts of which contacting the part of a paper web, where moisture shall be increased or further moisture loss shall be prevented, being damped.

Abstract: A vacuum dual control system for the flat box section of a papermaking machine. The system includes a plurality of serially arranged vacuum boxes and a header interconnecting the boxes. A vacuum pump is operatively connected to the boxes in a manner so that vacuum applied to the boxes is a function of the speed of the pump. A first control operates the pump to run at an initial substantially constant high speed for providing vacuum necessary to dewater a web in its initial condition. The web is passed over the boxes so that suction applied therethrough by the pump running at its initial substantially constant high speed dewaters the web until the condition of the web changes sufficiently to cause the vacuum in the last box to increase to a predetermined maximum level. A second control is provided with set point adjustment capabilities to enable selection of a predetermined set point corresponding to the predetermined maximum vacuum level.

Abstract: A moisture control system is provided for controlling the amount of chemical added to a fabric. The system includes a suction pipe having a slot therein and a fabric positioned to pass over the slot. A vacuum source is connected through conduit means to the suction pipe. A source of liquid is provided including a predetermined percentage of chemical therein to be added to the fabric. Liquid from the liquid source is added to the fabric and the fabric containing the liquid from the liquid source is advanced over the suction pipe whereupon vacuum is applied to the fabric to deliquefy it. The vacuum source is set to provide a predetermined vacuum depending on the chemical concentration of the liquid and the composition of the fabric. As the fabric passes over the slot a change in the vacuum is sensed and the vacuum source is actuated to retain the vacuum to the predetermined condition thereby maintaining a constant moisture level and amount of added chemical in the fabric.

Abstract: Pulp vat apparatus for applying pulp to a plurality of conductors in which a pulp vat has a cylinder mould with axially spaced annular perforate regions, one for each conductor, and the vat is divided by partitions into compartments, one for each perforate region. There is a flow inlet for pulp into each compartment and means to vary the pulp flow rate through each inlet independently of the flow rate through the other inlets whereby the level of pulp in each compartment is variable independently of the other compartments.

Abstract: Apparatus and method for insulating wires with pulp are disclosed wherein wires embedded in pulp ribbons supported upon an endless transfer belt are passed through radio-frequency electromagnetic fields generated by oscillators tuned to resonate at a high voltage level whenever a wire is not present and thereby energize a wire break alarm.

Abstract: Consistency of slurries such as paper pulp stock is controlled by ultrasonically measuring the flow of the slurry (the velocity of the particles therein) as the slurry is agitated by an impeller which induces circulation thereof within a region in a tank containing the slurry. Dilutant is added under the control of the measurement and a mixed slurry of desired consistency is obtained, respectively at an inlet and an outlet in communication with the region of the tank where flow is being induced and measured. Consistency control is obtained in the containing vessel or tank with greater accuracy and at lower cost than in apparatus where consistency is measured outside of the vessel containing the slurry.

Abstract: A vacuum control system and method for dewatering fabrics on a papermaking machine including a suction pipe and a vacuum pump connected to the suction pipe to supply a desired vacuum level. The fabric is passed over a slot in the suction pipe so that suction applied therethrough will dewater the fabric. Controls are connected to the suction pipe and to the vacuum pump responsive to an increase in the vacuum level in the suction pipe as fabric permeability decreases to correspondingly lower the speed of the vacuum pump and retain the desired vacuum level in the suction pipe.

Abstract: A method and an apparatus for determining the fibre length distribution by weight of a pulp and a method and apparatus for determining absolute consistency are disclosed.The fibre length distribution is obtained by dividing the flow of a pulp sample into two separate flows, fractionating each of the flows by a screen into a retained and a through fraction, the screens being of different mesh sizes, measuring the amounts of each of a selected one of said retained or through fractions and determining, based on the cumulative normal distribution relationship of cumulative retained fraction in % of feed to fibre length, the fibre length distribution of the pulp sample.

Abstract: A constant vacuum felt dewatering system including first and second suction pipes with a slot in each pipe. A felt is positioned to pass over the slots of the pipes. A liquid ring pump is connected by conduits to the first and second suction pipes. Drive structure is provided to operate the liquid ring pump and apply suction to the first and second suction pipes. The felt is advanced over the pipes whereupon suction is applied thereto to dewater the felt. Controls are responsive to change in felt conditions to vary the dwell time of the felt with respect to the slots in order to maintain a substantially constant vacuum.

Abstract: Web flutter is suppressed by means of one or more foils along the path of movement of the web which may be porous, such as tissue, whether creped or not, or may be substantially non-porous. For porous web, the foil may be imperforate. For non-porous web, the foil may be foraminous. As the web travels at high speed in adjacently spaced relation to the foil, surface air pressure tends to be greater on the surface of the web opposite the web surface which faces the foil, thus tending to thrust the travelling web toward the foil, and thus stabilizing web travel and suppressing tendency for the web to flutter as it travels freely between supports such as a dryer and a calender.

Abstract: A particular papermachine and type of pulp stock for forming a particular basis weight web are analyzed for deriving a correlation between pulp stock drainage rate and the lowest obtainable critical moisture content of said paper web. From knowledge of the lowest critical moisture content and main steam pressure, differential pressure values between the several dryer pressure sections of the papermachine are determined for drying said web along the most energy-efficient drying rate trajectory. Also disclosed is a dryer steam pressure differential control program for maintenance of a pre-determined magnitude of condensate inventory within the drying cylinders under normal running conditions and under conditions of interrupted web continuity.

Abstract: When a suspension is exposed to a field of ultrasound, a voltage can be tapped from two electrodes whose distance apart is an odd multiple of half ultrasonic wavelengths, and this voltage can be used as a controlling factor for the addition of, preferably, retention and flocculating agents to the suspension. The process is particularly suitable for fibre suspensions for the purpose of monitoring the starting process in paper machines and for rapid operating control.

Abstract: In a feedback color control system for controlling the flows of two colorants used to color an article, a first error signal is generated as a function of deviations in the color saturation of the article from a desired saturation, and a second error signal is generated as a function of deviations in the hue of the article from a desired hue. The flows of the dyes are varied in the same sense in response to the first error signal and are varied in opposite senses in response to the second error signal.

Abstract: A method and apparatus is described for obtaining a quantitative indication of paper web abrasiveness as the web subject of the test is in transit through the production machine. Test specimens of thin, sheet metal shim stock are held in light bearing pressure contact against the dry, finished or nearly finished web for a measured increment of web length. The measured quantity of specimen material lost to the measured quantity of passing web will yield a quotient indicative of the relative abrasiveness of the subject web.

Abstract: A steam shower for reducing paper web moisture content variability in the cross machine direction is described. The local dewatering effect of the shower on the moving supported web is controlled by varying its bottom steam discharge area incrementally across the width of the web. In one embodiment the hood is divided across the width of the machine into compartments, each having at least one cross machine direction wall whose bottom edge may be adjusted relative to the rear wall of the hood. A second embodiment has a pleated curtain whose bottom edge is controlled by lever arms with respect to the hood's rear wall. Local adjustments are made based on a comparison of moisture measurements at the finished product reel with the desired level.

Abstract: A non-laminated paper sheet product characterized by regions or islands of increased thickness, usually located in the center of the sheet for more economical use of the paper product and for conservation of wood pulp. The regions of increased thickness are formed by depositing or laying additional pulp stock onto a generally uniform thickness paper web in the web-forming area of a paper machine in either wet or dry methods of paper production. Continuous regions of increased thickness in the web can be formed by corresponding variations in the width of the web or by spraying the additional pulp onto the forming web. Islands of increased web thickness can be formed by periodically interrupting pulp stock depositing sprayheads disposed at spaced locations across the width of the forming web, with timing devices or web thickness sensors controlling the sprayheads.

Abstract: A sample of mineral fibers is dispersed in a liquid and viscosity of the dispersion is measured. The viscosity value provides a rapid measure of the length of the fibers. The measurement is sufficiently rapid that adjustments can be made to operating conditions during a production run to ensure the production of fibers of uniform length characteristics.

Abstract: A method of, and apparatus for, measuring the throughflow quantity of a liquid substance per unit of time in a papermaking machine, wherein the measurement is undertaken on the basis of the pressure drop at a throttling element, there being used as the throttling element a perforated plate having a multiplicity of parallel channels through which the substance flows.

Abstract: Continuously running web material is transferred from a dryer, or the like, to a proximate calender, or the like, along flutter suppressing foils. The web may be calendered in a nip between a rotary calender roll and a reel drum with which a reel core is in nip relation for winding the web on the core. The calender may comprise a single roll or a plurality of rolls. A split torque arrangement is provided for the reel drum and the reel core. Especially useful for handling creped tissue paper web.

Abstract: A method and apparatus for forming a multi-ply web of paper wherein a first layer is carried on the underside of a traveling felt to a bonding station located over the top of a forming cylinder on which a second layer is formed with a water bead in the nip between the layers and a laser or other device for generating a beam of energy at one end of the nip directing the energy along the water bead parallel to the nip and a receiver at the other end to detect the laser beam with means operated by the receiver for controlling the size of the water bead.

Abstract: The characteristic profile of a paper web is adjusted on the fourdrinier by means of a number of fluid spray stations positioned across the papermachine. Each spray station is provided with two or more fan spray nozzles of different flow capacity oriented to impact the pond with fluid along a common line. Flow to each nozzle is binary controlled with respective binary command, full flow valves. By discrete manipulation of valve selection, total flow rate to the web may be adjusted without flow throttling and consequent impact velocity variations.

Abstract: A method of on-line control of opacity of moving sheet material being produced by a paper making machine includes an opacity control loop where an opacity additive is controlled and a basis weight control loop where the stock input to a headbox is controlled. These two control loops are decoupled by means of an opacity to stock feed forward and a basis weight to titanium dioxide feed forward. In addition, the effect of moisture change is decoupled from opacity.

Abstract: A surface sensor utilizing a light source for projecting light onto a travelling surface and thereby illuminate a limited area of said surface is combined with at least two angularly spaced sensors and arranged to detect light reflected. Signals are generated in accordance with the amount of light received and these signals are processed to obtain at least one of (a) an indication of topographical surface characteristics of the web surface while suppressing the effects of changes in reflectivity of the surface and (b) indication of the change in reflectivity while suppressing the effects of topography of the surface.

Abstract: At least one channel in a multi-channel paper machine distributor is maintained in flow velocity slave relation to another of the channels by monitoring the velocity with a pressure transducer of stock flow through the latter channel and by such monitoring controlling the stock velocity in the slave channel.

Abstract: A process for controlling the dry density of ceiling tile where a delayed measurement of thickness or caliper is compared with an off-line oven dry basis weight measurement of a previously taken sample to provide dry density which is then compared to a dry density target to yield an error signal which updates an on-line wet density indication to provide control of stock flow.

Abstract: Apparatus in which a sample of pulp flowing through a conduit is periodically introduced into a cylinder. The pulp is deposited upon the strainer element of a piston assembly so as to form a fiber cake which, after formation, is utilized to test the flow of water therethrough over a predetermined time interval in order to measure the degree of beating of the pulp flowing through the conduit. In order to form a fiber cake upon the piston strainer element in which the layers are of substantially uniform density, water at a pressure higher than that utilized during the test period is introduced into the test cylinder and in a direction substantially tangential to the interior surface of the cylinder in order to set up a rotating flow of fluid facilitating formation of fiber cake layers of uniform density.

Abstract: A method for the control of basis weight of a sheet material made from liquid stock controls the consistency of liquid stock flowing to a flow box by a consistency feedback loop, and varies the level of liquid stock in the flow box to effect a change in the flow of dry fiber to the sheet former. Level is maintained in a midrange and any level called for outside of midrange is handled by adjusting consistency.

Abstract: A slurry of cellulosic material is diluted to a flowable consistency and subjected to a pressure differential on a permeable surface to increase the slurry consistency to a value between the consistency of the diluted slurry and the consistency of the slurry prior to dilution thereby forming a mat of cellulosic material on the permeable surface. The liquid and solids which pass through the permeable surface as a result of the pressure differential are recycled for use as slurry diluent, and to the mat of cellulosic material, while the mat remains on the permeable surface and subject to the pressure differential, is countercurrently applied, in a plurality of treatment stages, a treating liquid, such as a wash liquid, including application of a fresh treating liquid to said mat in the last stage of said treatment stages, whereby the treating liquid displaces at least a portion of liquid present in said mat from said mat and through the permeable surface in each treatment stage.