A method for determining a property of a fiber suspension comprises obtaining a sample and diluting the sample by a first dilution, thereby providing a diluted sample, while retaining essentially all of the sample, and mixing the diluted sample, thereby providing a mixed, diluted sample. By removing part of the mixed, diluted sample and retaining an amount of the mixed, diluted sample, further diluting the mixed, diluted sample by adding dilution water to the retained amount of the mixed, diluted sample, thereby providing a further diluted sample, while retaining essentially all of the mixed, diluted sample, mixing the further diluted sample, thereby providing a mixed, further diluted sample, and repeating these steps until the concentration is suitable for measuring the property of the further diluted sample, this property can be measured with high accuracy. A device for determining a property to be determined of a suspension is also provided.

The invention relates to a method, a computer program product and a machine vision system (30), comprising at least one lighting device (34), at least one image sensor (31 a-c) and a data processing device (32), the system in a first mode illuminating a first object (35) using a first type of illumination and capturing images of the first object at a first image capturing frequency, when the first object (35) is on a second object (33), transmitting the captured image data to the data processing device for analysis, and changing the system for monitoring the second object in a second mode, if absence of the first object on the second object is detected from the image data, wherein said at least one image sensor (31 a-c) is reconfigured to capture images at a second image capturing frequency from the second object.

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

A method for determining the dryness of a fibrous web, in particular a tissue web, during the production of the fibrous web, is carried out in a machine including a drying cylinder, in particular a Yankee cylinder, to which at least one, preferably two, dryer hoods are assigned, and a reel-up for winding up the fibrous web. The determination of the dryness of the fibrous web is carried out before the drying cylinder on the basis of measured values which describe the following variables: the amount of solids in the fiber web at the reel-up, the amount of water in the fiber web at the reel-up, and the amount of water which is evaporated in the dryer hood or hoods. A method for controlling or regulating a machine for producing a fibrous web, a computer program and computer program product are also provided.

A fiber assembly-forming method includes forming a web containing a plurality of fibers charged to a first polarity on a transport belt charged to a second polarity opposite to the first polarity and applying a liquid to the web formed on the transport belt from a nozzle of a liquid coater. The liquid contains a binder binding the fibers.

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

A process having the steps of producing the web material with the papermaking machine; measuring a molar amount of a monovalent inorganic ionizable cation species (MIICS) in the web material; measuring a molar amount of a divalent inorganic ionizable cation species (DIICS) in the web material; calculating a molar ratio of the measured molar amount of the MIICS to the measured molar amount of the DIICS in the web material; determining if the molar ratio of MIICS to DIICS is about less than or equal to 10; and, if the molar ratio of MIICS to DIICS is greater than about 10, adding an amount of DIICS to the papermaking machine to adjust the molar ratio of MIICS to DIICS so the web material adhering to the Yankee drum drying system has a molar ratio of MIICS to DIICS of about less than or equal to 10, is disclosed.

A process for manufacturing a web material is disclosed. The process generally comprises the steps of providing a papermaking machine with a monovalent inorganic ionizable cation species (MIICS) and a divalent inorganic ionizable cation species (DIICS) measuring devices, measuring molar concentrations of MIICS and DIICS in the web material with the MIICS and DIICS measuring devices and calculating a molar ratio of the measured molar concentration of the MIICS to the measured molar concentration of the DIICS, and subsequently determining if the calculated molar ratio is about less than or equal to 10. If the molar ratio is greater than 10, adding an amount of DIICS to the papermaking machine and manufacturing the web material with the papermaking machine with the added amount of DIICS.

The invention relates to a method of threading a fibrous web (W) onto a circular cylindrical object (3, 19) in a reel-up (2) for a paper-making machine (1). The reel-up (2) comprises an endless flexible belt (6) mounted for rotation along a predetermined path of travel. The endless flexible belt (6) is positioned adjacent the circular cylindrical object (3, 19) during winding and the fibrous web (W) residing on the outside surface (8) to engage the circular cylindrical object (3, 19) during winding such that the endless flexible belt (6) is deflected from the predetermined path of travel. When a fibrous web (W) is to be threaded onto the circular cylindrical object (3, 19), the circular cylindrical object (3, 19) is placed at a distance from the endless flexible belt (6) such that the endless flexible belt (6) is no longer deflected from the its path of travel. A narrow tail (17) is cut from a fibrous web (W) that is to be threaded and the narrow tail (17) is advanced on the outside surface (8) of the endless flexible belt (6). The circular cylindrical object (3, 19) is moved towards the endless flexible belt (6) such that the circular cylindrical object (3, 19) comes into contact with the narrow tail (17) and an adhesive substance is applied to the to the narrow tail (17) such that the narrow tail (17) will adhere to the circular cylindrical object and starts to be wound on the circular cylindrical object (3, 19), whereafter the narrow tail (17) is widened. The invention also relates to a reel-up (2) capable of carrying out the method.

A controller for controlling a slurry flowing from incoming piping and entering hydrocyclones arranged in a battery configuration, featuring a signal processor that receives signaling containing information about respective individual cyclone control signaling x(i) for each individual cyclone being evaluated and controlled, median control signaling {tilde over (x)} of all of the respective individual cyclone control signaling x(i), a scale factor A.sub.i and a number N of the individual cyclones being evaluated and controlled; and determine/provides primary control signaling C containing information to control the slurry flowing from the incoming piping and entering the hydrocyclones arranged in the battery configuration by taking the median control signaling {tilde over (x)} and adding a correction factor, where the correction factor is determined by taking a sum of a respective difference of each of the respective individual cyclone control signaling x(i) and the median control signaling {tilde over (x)}, applying the scaling factor A.sub.i to each respective difference, and normalizing the sum by the number N of the individual cyclones being evaluated and controlled, based upon the signaling received.