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: 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: Method and equipment for the manufacture of corrugated paper products includes separate heaters for preparing liner and medium components. Data regarding these components is collected and an optimum conditioning for the components is determined.

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 device in a paper machine or in a finishing device of a paper machine for removing dust in which a blowing is directed at a web to cause the separation of dust from the web and a suction effect is applied to the web to remove the dust separated from the web. A vortex flow is produced before the dust separating blowing in the running direction of the web to prevent carriage of the dust into the environment and to compensate for the suction effect on the runnability of the web. In the device, blow elements produce a blowing that separates dust from the web and suction elements produce a suction effect so as to remove the dust that is separated out of connection with the web. The device includes an arrangement for producing a vortex flow before the dust separation blowing in the running direction of the web to prevent carriage of the dust into the environment and to compensate for the suction effect.

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: A predetermined number of actuators are arranged transversally to a continuously produced material web for adjusting the cross-sectional profile of the web. To determine to what degree the instantaneous cross-sectional profile can approximate a reference profile, an optimally achievable profile is determined first in a computing device on the basis of a measured profile and a mathematical model of a controlled system of a cross-sectional profile control, and the optimally achievable profile is compared with the measured profile.

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: A measuring device scanning from edge to edge of a continuously fed sheet includes two sensing heads spaced apart from the sheet by air cushions whose thickness is not influenced by pressure of supplied air and is subjected to an invariable approaching gravimetric force. The air cushions are preferably formed of air jets from calibrated holes at the inside of both sensing heads, each of said holes being surrounded by annular barriers with circular rims. While the approaching force applied to the upper head is given by the own weight of the latter, the corresponding opposed force on the lower head is provided by a pressure regulator of internal air at the inside of the lower sensing head.

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: The invention relates to a scanning device (1) for measuring physical properties of a moving fibrous web (2) which has two longitudinal edges and is intended to run in a predetermined path of movement past or through the scanning device (1). The device (1) has a carriage (11) carrying a scanning head (14). The carriage (11) is movably supported for movement transversely to the direction of movement of the web (2). A drive (12) is provided which imparts to the carriage (11) a reciprocating movement from one edge side of the web (2) to the other, during which the scanning of the web (2) is carried out. The scanning device (1) is fitted with means (21, 31, 32, 33, 36) associated with the carriage for providing, in essentially the same plane as the predetermined path of movement of the web (f), a planar web supporting surface at locations between the carriage (11) and the two longitudinal edges of the web (2) during passage of the web (2) past the scanning device (1).

Abstract: An apparatus for web monitoring in paper making machines comprises a row of two or more lookers (6, 8) which are spaced across the width of the moving paper web. Each looker is stationery, and continuously inspects one or more small areas of the web as the web passes beneath. Optical signals from each individual inspection area are digitized, and spatial filtering is used to remove from the signals the effects of variations in the web which are much larger or much smaller than the variations being studied. A number of power spectra are calculated from the spatially filtered signals, and analysis of these functions is then used to identify significant features. Plots or tables of such features can be used to provide detailed information for the machine operator on the types of variations that are occurring in the paper web, and the possible causes of these variations.

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: 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: 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 method for the quantification of the wet strength of paper in pulp and/or paper, comprising(I) developing a calibration model by(I.a) registering absorption, reflectance or emission spectra of reference samples of known wet strength to develop learning sets;(I.b) processing the spectral raw data, to reduce noise and adjust for drift and diffuse light scatter;(I.c) performing a data analysis by applying chemometric techniques to the processed learning sets; and(II) determining the unknown paper wet strength by registering the absorption, reflectance or emission spectra, in correspondence to (I.a), from the pulp and/or paper of the unknown wet strength; processing the thereby obtained spectral raw data as according to (I.b); and applying the developed calibration model to the processed data.Optionally, a data analysis step as according to (I.c) can also be applied to the processed spectral raw data from the paper having unknown wet strength.

Abstract: An apparatus for controlling the degree of fiber variations in paper sheet has a formation meter for receiving an image of transmitted light on one side of an area of paper from a light source located on the other side of the area of paper, an image processing computing element for introducing the image from said formation meter for image processing and a fuzzy control unit for calculating and outputting optimum J/W ratio, optimum foil angle, and optimum deflector pushing degree and angle on the basis of results of image processing from said image processing computing element.

Abstract: A rapid method is provided for the on-line determination of sodium sulfide concentration and/or percent sulfidity in green liquors or smelt solutions used for the production of either kraft or sulfite pulp. The method eliminates manual sampling, and the need for frequent equipment maintenance.

Abstract: The invention is directed to a continuous belt edge detector system for use in a paper making machine having a continuous belt guide device. The edge detector system comprises a continuous belt having an edge dope with metallic particles therein and an inductive sensor connected to the guide device and adjacent the edge dope. The inductive sensor sends a signal to the guide device indicative of a location of the continuous belt. The guide device moves the continuous belt, e.g., transversely relative to the running direction of the belt within the machine, dependent on the inductive sensor signal.

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: 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: A digester temperature distribution control system comprises an optical fiber type temperature measuring unit utilizing the Raman scattering effect, reference temperature measuring unit, reference point temperature setting unit, measured temperature distribution calculating unit, target temperature distribution calculating unit and control unit. The optical fiber type temperature measuring unit is provided in that digester charged with chips and equipped with control valves for controlling steam for heating the charged chip mass in the digester and is adapted to detect temperature at a plurality of points in a length thereof including a given reference point in the digester.

Abstract: A method and apparatus are described for continuously sampling a process stream, or reservoir of aqueous cellulosic pulp and detecting oversize contaminants in the sampled stream. This serves the overall objective of estimating the level of contamination in the process stream or reservoir during a given period of production; the method may include the following stages: 1) a continuous sample stream is drawn from the process or main stream, 2) the stream is passed through a centrifugal device which divides the sampled stream according to density, 3) the stream with the higher level of contaminants from the centrifugal device is passed to a screen which isolates the contaminants, and 4) the contaminants are flushed from the screen so that they can be quantified; these measurements are used to assess the purity of the material being produced. One useful application of this invention is to assess the presence of trace amounts of plastic contaminants in the production of the cellulosic pulp.

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: Apparatus for measuring a characteristic of a body of material having first and second substantially parallel coaxial lines with distal extremities in relatively close proximity to each other and adpapted to be disposed in close proximity to the body of material. A transmitter is coupled to the first coaxial line for introducing electrical energy in the high frequency to a microwave range into the first coaxial line to cause an electromagnetic field to be established at the distal extremity of the first coaxial line and to extend into the body of material. A receiver is coupled to the second coaxial line for detecting any of the electromagnetic field coupled into it from the first coaxial line. A measurement device is coupled to the receiver means for ascertaining when any change occurs in the coupling of the electromagnetic field from the first coaxial line to the second coaxial line to determine said characteristic of the body of material.

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 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: 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: 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: A sample of slurry is withdrawn continuously from a pressure pipe through which the slurry flows by a diluting sample-extractor mounted on the pipe. Dilution water is added continuously to the extractor to mix with the withdrawn sample to provide dilute slurry, and the quality of the dilute slurry is evaluated by passing it through a viewing window chamber and taking periodic photographs of the dilute slurry passing through such viewing window chamber.

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

Abstract: A method and apparatus for normalizing spectral data for an optical sensor. The sensor is comprised of a probe, a color sensor, a series of reflective targets, and a data processing means. Before the sensor is put into operation, a model is created, the use of which can normalize spectral data output by the color sensor for a variety of defined parameters. During operation of the sensor, the model maybe updated by rotating the targets individually in front of the probe. The targets have known reflectivities and the difference between the actual reflectivity and the spectral data is used to update the model.

Abstract: A method for determining the tendency of a non-woven web to curl, where the web has a machine direction (MD), a cross-machine direction (CD) and the web includes a wire side and a felt side. The method comprises determining a wire ratio which is the ratio of the number of fibers oriented in the MD to the number of fibers oriented in the CD, where the fibers are associated with the wire side of the web, a felt ratio which is the ratio of the number of fibers oriented in the MD to the number of fibers oriented in the CD, where the fibers are associated with the felt side of the web, and determining the wire to felt ratio which is a measure of the tendency of the web to curl.

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.

Abstract: Laboratory equipment for practicing experiments and mixing ozone with medium consistency cellulosic pulp allows precise control of the timing and amount of ozone injected into the mixer, providing a method of testing that is more accurate than prior methods. An injection cylinder and fluidizing laboratory mixer are utilized. Pulp is fed into the mixer, the cylinder is charged with a known predetermined amount of ozone containing gas, the ozone containing gas is injected from the cylinder into the mixer, the mixer is operated to effect mixing of the ozone containing gas with the pulp for a predetermined period of time, and then gas containing residual ozone (which has not reacted with the pulp) from the mixer is vented from the mixer, including by utilizing a purge gas such as nitrogen. The ozone is created by an ozone generator which continuously operates. A three-way valve directs the output of the ozone generator to an ozone destruction device when the ozone is not being charged into the cylinder.

Abstract: A method for measuring a pressure dependent characteristic of a dispersion of a solid material in a fluid, comprising passing the fluid through a screen until a pad of the solid material is formed on the screen and, thereafter, measuring said characteristic, characterised in that the pressure on the screen side of the pad is maintained at a predetermined value, with respect to the pressure on the opposing side of the pad, during a measurement of the characteristic.

Abstract: A method is provided to monitor specific filtration resistance, total drainage resistance and drainage flow rate in a continuous on-line manner in the paper making process. It can be combined with the simultaneous measurement of streaming potential or zeta potential so as to enable optimization of the chemistry of the papermaking process.

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 method and apparatus supply ozone containing gas under superatmospheric pressure to an ozone delignification device. The speed of a water ring compressor is controlled so that it compresses as much ozone gas per unit time at desired superatmospheric pressure as the ozone delignification unit utilizes, with essentially no excess. The ozone containing gas is fed from the water ring compressor through a separator buffer tank which levels out pressure pulses and separates cooling water from compressed ozone gas prior to the gas entering the ozone delignification unit. The gas passes through a control valve controlled by a mass flowmeter which senses the amount of cellulose pulp fed to the ozone delignification unit. The speed control of the compressor may be provided by a differential pressure controller connected across the control valve.

Abstract: A procedure and apparatus for locating faults in the machine elements of a paper machine and in their functioning, wherein variations in the paper characteristics are continuously observed, the periodicity of the variations is recorded and the periodicity of the variations in the paper characteristics is compared with the periodicity in the functioning of the paper machine's machine elements. The apparatus comprises observation members (1-11) for observing the variations occurring in the paper characteristics; synchronizing pick-ups (43-53) disposed on machine elements (13-22) of the paper machine for observing the periodicity of the functioning of said machine elements; a recording means (40) for recording the periodicity of the variations in paper characteristics and the periodicity in the functioning of the machine elements; and a data processing unit (41) for comparing the periodicity of the variations in paper characteristics and that in the functioning of the machine elements.

Abstract: The invention relates to a measuring apparatus for measuring the condition of a felt in a paper machine, comprising a measuring head (1) connected to a vacuum source. Air is sucked into the measuring head through the felt, and the air and the water carried with the air are removed through separate conduits. The measuring head comprises a microwave head for measuring the water content of the felt, and a temperature detector for measuring the temperature of the sucked air concurrently with the vacuum measurement.

Abstract: An apparatus and method to simultaneously evaluate the drainage, retention and formation characteristics of paper pulp comprising mixing the paper pulp furnish in the top chamber of the apparatus, releasing the furnish into a middle chamber via a valve having a cone shaped structure for even distribution of the furnish onto a wire screen, and utilizing a time delay before opening a vent valve in order to attenuate impingement forces. The apparatus utilizes a rotating blade under the wire screen to duplicate the pulsation forces of full scale papermaking equipment, an externally applied means to assist in the removal of water similar to a paper machine couch roll. Data generated during the foregoing steps is fed into a computer to evaluate the entire free water drainage process of the furnish. The device is able to set parameters to simulate the water removal process on most paper machines via level control and duration of pertinent variables.

Abstract: A measuring bridge, fixed in place above a moving paper web and disposed crosswise to it, is provided, having a measuring head, movable back and forth--crosswise to the paper web--, for determining the measuring values for judging the thickness of the paper web at the measuring spots or point on top of which the measuring head happens to be. The measuring device, has a process management system, in which a traversing flow program has been installed, in accordance with which the traversing time and/or the reversing time of the measuring head are changed after each traverse of the measuring bridge. Because of this, the frequency of the measurements along the web becomes irregular. This prevents false evaluations of the cross section and, as a consequence, inappropriate control instructions of a control computer.

Abstract: In a paper making machine, a strip of paper is caused to pass around part of the periphery of a rotary device comprising a plurality of cylindrical bodies arranged side-by-side across the width of the strip and each body has means for producing a signal representing the tension in the portion of the strip which controls the body, the thickness of the portions is also measured. From this data, control signals are produced representing the stress per unit of cross-sectional area of the portions of the strip and the paper making machine is controlled to keep the control signals constant across the width of the strip.

Abstract: Apparatus for cooling the end portions of a calender roll which has an elastic layer adjacent its peripheral surface and wherein the central portion of the peripheral surface is overlapped by a running web of paper or other material when the calender is in use. The width of the non-overlapped portions of the peripheral surface of the roll varies when a web having a first width is followed by a web having a different second width. This could lead to damage to the roll at the non-overlapped portions of the peripheral surface as a result of overheating by an adjacent rotary component of the calender. The end portions of the roll are cooled by discrete adjustable cooling devices which are movable along the respective non-overlapped portions of the peripheral surface in parallelism with the axis of the roll and each of which shares movements with a monitoring device which is to be maintained in a selected position relative to the adjacent marginal portion of a running web.

Abstract: A method and apparatus for detecting residual ink in a sample by illuminating by diffused infra-red light a series of spots on a sample and examining a small area on each spot by collecting light in a video camera to form a frame for each spot, digitizing each of the frame and detecting areas in the frames having a brightness below a selected level to determine the total dark area of each frame. The number of such frames processed in a set of frames used to categorize the sample is defined when a certain minimum number of frames have been processed and when a selected degree of convergence of the data collected for the set and the data from the frame currently being processed is obtained, or after a preset maximum number of frames have been processed. The sample is characterised on the basis of the ratio of the dark area to the total area processed.