Abstract: Method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The method includes determining a basis weight at an end of the manufacturing process, calculating a deviation of the determined basis weight from a predetermined target value, adjusting a concentration of a material suspension supplied to a headbox via a first control loop such that the calculated deviation is corrected, one of directly and indirectly measuring a basis weight of a resulting web in a region upstream, with regard to a web travel direction, a drying section, and supplying a signal related to the measured basis weight to a second control loop.

Abstract: A method for increasing caliper control of a fibrous web as the web is wound onto a roll is provided. The method includes winding the fibrous web containing cellulosic fiber onto the roll to form a wound product and conveying the web through a nip prior to winding the web onto the roll. The nip is configured to apply a pressure to the web to selectively decrease the caliper of the web as the web is wound onto the roll. Also disclosed is a system for controlling the caliper of the fibrous web in which a calender device forms a nip through which the fibrous web is conveyed. The system includes an adjustment device, which is configured to adjust the nip of the calender device to increase pressure on the fibrous web as the diameter of the roll increases thus increasing uniformity of the caliper of the fibrous web.

Abstract: Pressurized web treatment systems include a moving web that passes through a pressurized treatment chamber having a sealing assembly with a leakage control system. Leakage control is achieved by the cooperative effect of localized leak detectors and leak reduction means that applies a local sealing force on the seal assembly responsive to a signal from the leak detectors such that increased sealing occurs in the vicinity of the leak. In particular, an air press for paper web dewatering has improved efficiency by virtue of the leakage control system, which features local leak detectors and local force generation means associated with a flexible seal assembly to reduce leakage at the edges of the stationary plenum of the air press. Local leak detection can be based on sonic measurement with microphones, detection of escaping tracer gas, optical signals, and other means.

Abstract: In the method for manufacturing surface-treated printing paper, a paper web is first dried down to a target moisture of the surface treatment, and it is wetted again to the target moisture before the surface treatment. The rewetting to the target moisture is conducted on the web running to the surface treatment before a device effecting the surface treatment of the web, as seen in the travel direction of the web. Before re-wetting, the moisture profile of the web is adjusted in the drying section by wetting the web at a point which is located before the area of the heavy shrinkage (cd shrinkage area) in the travel direction of the web.

Abstract: An improved measuring system used with a process control system provides substantially real time correction of aliasing effects in a system having moving equipment that exhibits periodic parameters while being monitored. The measuring/control system can be used with a rotating equipment process line, such as used in a paper mill, in which a measurement scanner travels in the cross direction of a moving web of material, while that same moving web of material continues to move in a longitudinal direction (the machine direction) transverse to the cross direction. The measuring/control system begins by acquiring data utilizing a time synchronous monitoring system that produces a count matrix and a measurement matrix of readings from the measurement scanner. After a sufficient number of data samples have been acquired, a correction matrix can be built.

Abstract: The invention concerns a method for optimizing the degree of flocculation in a headbox. The degree of flocculation is measured continuously from a stock flow (M1)/stock flows by means of a detector (R1) of flocculation, and the detector (R1) transmits a signal to a regulator (H1), which regulates the metering of retention agent (10) and/or fillers (11) and/or auxiliary chemicals (12) into the stock flow (M1)/stock flows continuously on the basis of the signal to an optimal level, which stock flow/flows is/are passed into the headbox (P1).

Abstract: A device for non-contact support of a continuous moving web of material employs an air clamp stabilizer that includes a Coanda slot and a backstep that is located downstream of the direction of the airflow extending from the Coanda slot. This configuration permits a Coanda jet to expand and to create an additional suction force. Vortex formation may also occur which further contributes to the strength of the suction force. As the web passes the stabilizer, an area of the web material rides on an air bearing that is maintained above the stabilizer surface and downstream of the backstep.

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: The invention relates to a doctor apparatus (10) in connection with a roll (T) in a paper or board machine. The doctor apparatus (10) comprises a doctor beam (12) of lightweight construction and that the doctor beam (12) is arranged to pivot on bearing means (13a1, 13a2 . . . ) (pivot movement arrow L1). In connection with the doctor beam there are loading members (14a1, 14a2), a relative linear movement taking place between the loading members (14a1, 14a2) and backup surfaces (12′, 15a′) when the doctor beam (12) is being oscillated.

Abstract: The present invention relates to improvement in a method for estimating a setting value of a dryer steam pressure after papermaking exchange according to simulation in a papermaking machine and an apparatus therefor, where a steam pressure setting value after papermaking exchange is estimated accurately by determining an in-hood air dry-bulb temperature on the basis of a difference between an in-drum steam temperature which has been just measured and an initial value of an in-drum steam temperature, thereby reducing a papermaking exchange time as well as reducing broke and improving the rate of operation.

Abstract: A test method for analyzing an OCC fiber pulp, to quantify the content therein of contaminants creating bleed-throughs in a paper product formed from the pulp. A sample of the pulp is formed into a sheet, and bleed-throughs are created from the contaminants therein by hot-pressing the sheet. A dye is applied to the sheet, to enhance contrast between areas of the sheet having bleed-throughs and areas of the sheet not having bleed-throughs. The contrasted sheet is analyzed to determine the quantity of contaminants that create bleed-throughs.

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 scanner for moving sheet materials such as a paper making machine provides the gauging heads which measure parameters such as basis weight and moisture entirely inside an enclosed tubular beam. Each gauging head is driven in a cross direction perpendicular to the moving sheet direction and includes a seal belt for dust and dirt protection by covering a slot in the beam, except where the gauging is located.

Abstract: Streak defects in web structures are characterized by electronically obtaining a plurality of results of a plurality of tests of a web structure, electronically determining a location of and/or a quantification of one or more streak defects based on the plurality of results, and electronically characterizing the streak defect(s) as being static or stochastic based on the plurality of results.

Abstract: Enzymatic methods are provided for determining the surface triglycerides content in a sample of wood pulp. The methods preferably comprise reacting triglycerides which are present on the surface of the wood pulp fibers in the sample in the presence of a lipase to form glycerol and fatty acids, and then determining the difference between the amount of free glycerol present in the sample and the amount of glycerol formed from said triglycerides. The method is useful as a quick, portable, accurate, and low cost assay for assessing the amount of triglycerides present at various sample points in pulp and paper mills, which advantageously serves as a diagnostic tool for use in controlling the undesirable deposition of pitch during the papermaking process.

Abstract: A mathematical model is used to design paper and paperboard having improved runnability. The mathematical model provides an estimate of fracture toughness for an optimized paper product based on specific measurement parameters, e.g., filler percent, softwood content and caliper for optimal fracture toughness. After the optimizing set of measurement parameters has been acquired, these parameters can be used to manufacture grades of paper having improved runnability performance, e.g., in printing presses.

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: Device and process for controlling or regulating a basis weight of a web in a web manufacturing process of a web producing machine. The device includes a first control circuit, adapted to adjust the basis weight, that includes at least one adjustable device for influencing the basis weight and at least one basis weight sensor. A second control circuit having at least one sensor for detecting a concentration of incoming backwater is also provided. The process includes measuring the basis weight of the material web, adjusting the basis weight of the web with a first control device having at least one device for influencing the basis weight, detecting a retention change in a second control circuit, and counteracting the retention change by influencing a concentration of a stock suspension placed one of onto a wire and between wires.

Abstract: A system and method for altering the tack of a material, namely a polymer used as an adhesive, also known as stickies, or pitch. The present invention reduces the tack of the stickies and pitch by exposing the materials for a short duration to low-energy pulsed electrical discharges between a pair of electrodes that are submerged in a liquid medium, such as a fiber stream, water, a pulp slurry, or whitewater.

Abstract: Method for manufacturing paper or cardboard in one or more plies in order to achieve a paper or cardboard product with an even quality. The method comprises determining a fiber composition of a broke paper or cardboard waste broke, fractionating the broke; and conveying at least one fiber fraction obtained thereby to a given ply in the paper or cardboard. In this way the fractionating is controlled so that the fiber composition in the fiber fraction obtained corresponds to a fiber composition in the input paper pulp for the given ply.

Abstract: The invention concerns a method for determination of an irreversible stretch and of a dynamic modulus of elasticity from a paper web (W). In the method, the irreversible stretch and the dynamic modulus of elasticity are determined from h paper web (W) by means of on-line measurement. The invention also concerns a method in which the quantities that have been determined are employed in the control of the papermaking process.

Abstract: The measuring device comprises at least one measuring head having a reference part, which comprises a reference surface against which the moving web is supported. The reference surface comprises a measuring area in the inside of which the property of the web is measured. The reference part is arranged in connection with the measuring head in such a way that below the reference part, there is a substantially open air space. The measuring head comprises means for generating negative pressure in the air space below the reference part, and the reference part comprises holes formed through it, in such a way that the negative pressure generated in the air space affects through the reference part the space between the reference surface and the moving web in such a way that the web is supported against the reference surface substantially over the whole area of the measuring area.

Abstract: In a method of monitoring the state of a felt serving for the dewatering of a fiber web, in particular of a paper web or of a cardboard web, the felt topography is measured and/or an image of the felt surface having definition in depth is produced by mean of an optical measuring device and the result of the measurement obtained is compared with previously stored error patterns by means of an evaluation and/or control unit. Corresponding felt conditioning measures are then initiated, preferably automatically, in dependence on the result of the comparison. A corresponding felt monitoring device is also described. In a further method of monitoring the state of a felt or screen serving the dewatering of a fiber web, in particular of a paper web or a cardboard web, specific felt and/or screen properties are determined permanently or cyclically at intervals and are filed under a pre-settable felt and/or screen name in a historical database.

Abstract: Disclosed is a system that adjusts the operational parameters of a fiber filter apparatus to keep measured properties indicative of paper quality, such as the paper's porosity, within desired value ranges. A feedback loop may be set up in which input properties are read, such as the paper's porosity and the pollution content of the filtrate leaving the fiber filter. These inputs go into a predictive model that determines how to adjust the fiber filter's operational parameters in order to move the measured paper quality properties into their desired value ranges while accommodating other constraints on the fiber filter's operation. The model looks at positive and negative correlations between the operational parameters and the measured inputs. Having processed the inputs and predicted an outcome, the predictive model directs controllers to change the operational parameters of the fiber filter. The input properties are again read, and the feedback loop is repeated.

Abstract: The method is used for determining a characteristic value for the binding force potential of paper fibers present in a fibrous suspension prepared for paper manufacture. According to the invention, the air content of the fibrous suspension is measured and this characteristic value derived therefrom. The correlation between the characteristic value and the air content ascertained can be discovered, e.g. by means of series of empirical measurements. With the aid of this method, e.g., the runnability on the paper machine can be assessed and corrected before breakdowns occur.

Abstract: A process and device to detect the presence of a fibrous material web in machines for manufacturing the same, whereby the fibrous material web is guided by at least one continuously circulating belt. The process includes measuring at least one of (1) a temperature of a side of the fibrous material web opposite the at least one belt while it is being supported by the at least one belt, (2) a temperature of a material web supporting side of the side of the at least one belt after transfer of the fibrous material web to a following unit, and (3) the temperature of a side of the at least one belt opposite the fibrous material web supporting side of the at least one belt. The process also includes detecting a change in the at least one measured temperature as an indicator of the presence or lack of fibrous material or the strip in an area in the machine in the vicinity of the measuring.

Abstract: A process and an apparatus for the manufacture of SC-A paper having a high gloss and high smoothness, wherein the paper arriving from the paper machine is supplied on-line to a supercalender (multinip soft calendar), and wherein the paper travels through a plurality of nips for achieving the desired gloss and smoothness properties. The paper web arriving from the paper machine and supplied on-line to a supercalender (multinip soft calendar) is moistened with steam immediately prior to the first nip of the supercalender and is guided through the first nip before the increased moisture of the surface resulting from the application of steam has dropped below a predetermined value in the range of 12% to 25%.

Abstract: A property of a paper web is measured using one or more reflectance measurement sensors emitting measuring beams onto the web and receiving the beams reflected from the web, from which the web property is deduced. The web is supported on a web support during the measurement, such as on a passive or active airfoil or fabric. One or more measurement sensor(s) can be integrated within an active airfoil, and can comprise a plurality of optical fibers having sensing ends arranged in the airfoil such that the sensing ends of the fibers face the moving paper web through one or more apertures in a web-supporting panel of the airfoil. Alternatively, a traversing sensor can be mounted within the airfoil. Other embodiments include a reflectance sensor mounted adjacent an airfoil or other web support such as a through-air drying fabric or a support belt for the web.

Abstract: The invention is directed to a system and method for implementing process control for paper elasticity and thickness using sonic NDE techniques. The system may, for example, generate ultrasound waves in a test object during the manufacturing process. A detector such as an interferometer may be used to detect the ultrasound waves. An interpreter or analyzer may determine the thickness and/or elastic properties of paper from the waves. Then, a control system may determine and implement an appropriate control action on the process.

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: A process and a device for drying and smoothing a web. The process uses an apparatus including at least one dryer section having a plurality of heated cylinders and a calender having a plurality of smoothing nips, and includes guiding the web over the plurality of heated cylinders in the at least one dryer section, drying the web in the at least one dryer section to a maximum dry content of approximately 93%, adjusting a moisture cross-profile of the web in the dryer section, and guiding the web to the calender. The device includes a dryer section comprising beginning, middle, and end sections, a calender, and at least one adjusting device located in the end section for moistening the web, wherein the web is guided through the dryer section prior to being guided to the calender.

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 mathematical model is used to design paper and paperboard having improved runnability. The mathematical model provides an estimate of fracture toughness for an optimized paper product based on specific measurement parameters, e.g., filler percent, softwood content and caliper for optimal fracture toughness. After the optimizing set of measurement parameters has been acquired, these parameters can be used to manufacture grades of paper having improved runnability performance, e.g., in printing presses.

Abstract: The solution of the invention relates to a method and apparatus for the treatment of a paper web in a paper or cardboard machine. The essential feature of the solution of the invention is that a moving material web (1), its properties and/or its behavior are influenced by the use of a gas (2) by causing the gas (2) to flow substantially toward the material web or to its immediate vicinity.

Abstract: A sensor apparatus and electrode configuration within the sensor apparatus for measuring electrical characteristics of an aqueous fibrous composition. The electrode configuration includes an elongated ground electrode and at least one segmented electrode to form an array of measurement electrode cells. The electrode configuration further includes an array of reference electrode cells formed by a plurality of reference electrodes built into the array of measurement electrode cells. The measurement electrode cells and reference electrode cells have a different sensitivity to water weight of the aqueous fibrous composition and the same sensitivity to conductivity of the aqueous fibrous composition. The measurement apparatus obtains simultaneous resistive measurements from both measurement and reference cells and determines the ratio of the measurements such that the affects from conductivity is canceled out of the measurement ratio.

Abstract: A sample collecting device takes samples from the white water drained from the web through the wire in the wire part, at a number of points in the cross direction of the web. An analyzer analyses the samples and forms a retention profile for controlling the paper machine. The device for measurement and regulation of the retention profile comprises means for measurement of the retention profile across the web width from different points of width of the web. The headbox comprises ducts passing to different points of width of the headbox to pass a flow of liquid containing a retention agent in the headbox into connection with the stock flow to regulate the retention profile across the web width. The ducts have valves which are regulated on the basis of the retention profile data for regulating the retention agent into duct flow.

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: A process is provided for operating a calender roll including a roll jacket surrounding an inner chamber. The process includes creating an active oscillation in the inner chamber that acts upon the roll jacket. By creating an oscillation within the calender roll, the appearance of undesired bar rings, which form on the external surface of the roll jacket due to operational exciting forces, is avoided. Furthermore, calender roll is provided including a roll jacket surrounding an inner chamber, and at least one actuator provided within said inner chamber acting upon said roll jacket.

Abstract: A method and an apparatus are provided for measuring the amount of entrained gases in a liquid sample. A conduit defining a volume is provided. The conduit has an inlet at a lower end thereof and an outlet at an upper end thereof. Liquid sample is made to flow into the inlet, through the conduit, and out of the outlet. The weight of the liquid sample in the conduit is determined during a flow of liquid sample through the conduit to obtain a first measurement. Thereafter, a difference between the first measurement and a predetermined weight value representing a weight of the same liquid sample flowing through the conduit but containing no entrained gases is determined to obtain a calculated weight of entrained gases in the liquid sample flowing through the conduit.

Abstract: Process for conditioning a circulating felt belt of a machine, pipe suction apparatus and traversing pipe suction apparatus therefor, the process including performing a zonal conditioning of a plurality of zones across a width of the felt belt by measuring at least one of, fibrous material web cross direction profile; felt belt cross direction profile; and permeability of the felt belt across the width of at least one of the web and the belt. The felt belt is conditioned depending on measuring results obtained for a respective zone. The pipe suction apparatus includes a ceramic body extending at least essentially across the entire width of the felt belt, the ceramic body being provided with a slotted surface by way of which the felt belt is subjectable to vacuum, with a respective effective amount of slotted surface being zonally variably adjustable by way of movable tongues.

Abstract: The present invention relates to improvement in a method for estimating a setting value of a dryer steam pressure after papermaking exchange according to simulation in a papermaking machine and an apparatus therefor, where a steam pressure setting value after papermaking exchange is estimated accurately by determining an in-hood air dry-bulb temperature on the basis of a difference between an in-drum steam temperature which has been just measured and an initial value of an in-drum steam temperature, thereby reducing a papermaking exchange time as well as reducing broke and improving the rate of operation.

Abstract: This invention relates to a novel on-line pulp digester control system. More particularly, this invention pertains to a novel control system which employs real time measurements from ion mobility spectrometry to automatically rapidly and continuously determine the physical and chemical characteristics of wood chip feedstock being fed into a pulp digester and thereby maximize process efficiencies, minimize chemical and energy consumption and improve product uniformity.

Abstract: Method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The method includes determining a basis weight at an end of the manufacturing process, calculating a deviation of the determined basis weight from a predetermined target value, adjusting a concentration of a material suspension supplied to a headbox via a first control loop such that the calculated deviation is corrected, one of directly and indirectly measuring a basis weight of a resulting web in a region upstream, with regard to a web travel direction, a drying section, and supplying a signal related to the measured basis weight to a second control loop.

Abstract: In controlling the dryer section of a paper machine, the basis weight and moisture of the paper web, the energy fed into the drying cylinders of the dryer section and the machine speed are measured, and then the surface temperature of the drying cylinders is predicted on the basis of the measured values. At the same time, the actual surface temperature of the dryer cylinders is also measured, and if the measured value deviates from the predicted value, any defects in the drying apparatus can be detected quickly. In another aspect, a determination is made of the normal correlation between the power consumption of the drive motors of the cylinders in the drying apparatus and the machine speed. These variables are also measured, and if the correlation of the variables is deviant, it can be concluded that there is a failure in the drying apparatus. In that case it is possible to identify the dryer cylinder where the failure is by measuring the temperature of the cylinders.

Abstract: The invention relates to a method and an apparatus for measuring properties of a moving web. Web properties are measured with a measuring apparatus where at least one sensor element is arranged to a rotating measuring roll. The measuring roll is in contact with the web to be measured, and the circumferential speed of the measuring roll is arranged to substantially equal the web speed, the web being substantially in non-slipping contact with the measuring roll for an arc of the rotation of the measuring roll.

Abstract: The object of the invention is a sampling apparatus in a continuous industrial process for taking a sample of the substance to be monitored. The sampling apparatus is located on the wall of the pulp tank and it includes a sample chamber, which is equipped with a cover, and a filter. The sample chamber includes a closing device, by means of which the connection from the pulp tank to the sample chamber can be closed, as a result of which the filter remains in the sample chamber in the space between the cover and the closing device. The filter can be pulled out of the sample chamber for cleaning after the cover of the sample chamber has been opened. Another object of the invention is a sampling method and a cleaning method for the sampling apparatus presented.

Abstract: A method of detecting streaks in a web of, for example, moving paper which may be moisture, basis weight or caliper. A cross-direction profile is sensed and a moving average computed and then using minimum thresholds for the variation of the streak value from the average and its width in profile data boxes, the streak is detected.

Abstract: A process for continuous reeling of a pulp sheet, particularly a paper sheet, where the sheet runs over a reel drum and is later wound on a winding unit. The pressing force in the nip between the horizontal reel and the reel drum being measured without any losses during the entire winding process. This process is implemented by a device having a reel drum and a horizontal reel supported on load-sensing devices.

Abstract: A system and process for measuring paper formation characteristics in real time is disclosed. The system comprises apparatus used in a papermaking process, and includes a rotating forming fabric having an upper and lower surface. A paper slurry is deposited upon the upper surface of the moving forming fabric to prepare a wet paper web. The wet paper web typically moves at a high rate of speed as it rides along upon the surface of the forming fabric Light is transmitted from a light source to the surface of the wet paper web, and then reflected from the surface of the wet paper web to a camera. An image is formed corresponding to the pattern of the reflected light, and in some instances data generated from the reflected light may be compared to other values to provide a feedback loop to adjust the parameters of the papermaking process in real time.

Abstract: The present invention provides a method for controlling a process by calculating a manipulated variable from a deviation between setpoint and control output variables and then using the manipulated variable, wherein the time-series data of the control output variable is subjected to a frequency analysis, the rate of change in the frequency response amplitude of the control output variable in relation to a control gain ratio is determined, and a control gain is adjusted according to the rate of change and the results of the frequency analysis.