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 fibrous body accumulating device includes an accumulating section including a drum that introduces and releases a material including fibers, a detection section detecting a presence of the material in the drum, and an estimation section estimating an amount of the material in the drum based on a detection frequency at which the detection section detects the material. The fibrous body accumulating device further includes a storage section in which a calibration curve showing a relationship between the detection frequency and the amount of the material in the drum is stored, and the estimation section calculates information on the detection frequency and estimates the amount of the material in the drum with reference to the calibration curve.

A defibrating unit that defibrates a raw material including fibers in an atmosphere, an accumulating unit that discharges defibrated matter by rotating a drum unit in which a plurality of openings are formed, a second web forming unit that forms a second web by operating a mesh belt on which the defibrated matter is accumulated, a sheet forming unit that forms a sheet from the second web, a cutting unit that cuts the sheet into a preset size, and a control unit that executes a stop control with a cut operation of the cutting unit as a trigger in a case where an instruction to stop an apparatus is provided are included. In the stop control, the control unit stops operation of the defibrating unit after stopping rotation of the drum unit and movement of the mesh belt.

A fiber body manufacturing method includes: a dispersing step of dispersing a mixture containing a defibrated material which includes fibers and a binding agent which exhibits a binding property by moisture absorption, the mixture having a moisture content of 10 to 30 percent by weight; a depositing step of depositing the mixture dispersed in the dispersing step; a humidifying step of imparting moisture by water vapor or mist to the binding agent in a deposit deposited in the depositing step so as to exhibit the binding property; and a forming step of forming the deposit humidified in the humidifying step into a fiber body.

A system for treating recycled cellulosic fibers to improve paper, board and tissue quality; the system involves fractionating recycled fibers into a short fiber portion and a long fiber portion. The short fiber portion is split into an original short fiber portion and a refinable portion. The refinable portion is processed into glue pulp. The glue pulp is refined to targeted, measured fiber properties. Varying amounts of the glue pulp, original short unrefined fibers, and long unrefined fibers are blended together to form an optimized slurry that is processed by a paper machine into an optimized recycled paper product. The process provides for improved drainage with the same or better paper properties allowing for cost reductions in fabrication.

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 system for treating cellulosic fibers to improve paper, board and tissue quality; the system involves splitting fibers into an original portion having original fibers and a refinable portion. The refinable portion may further be fractionated by one or more fibers properties by a fiber fractionation system into a first fraction and a second fraction. The refinable portion as a whole, or a fractionated fraction thereof, is then refined to produce refined fibers. Varying amounts of the original unrefined fibers, refined fibers and possibly additionally fractionated unrefined fibers are blended together to form an optimized slurry that is processed by a paper machine into an optimized paper product. A master control system, fiber measurement system and optional fractionation maintenance system may be integrated with the overall system to regulate all processing.

An apparatus for measuring flowing suspension includes a radiation source that directs wave motion to the suspension, a flow causing particles of the suspension to be sorted by size. A measuring arrangement measures first values of a first parameter of the wave motion interacted with the suspension at a first wavelength band of the wave motion, and measures second values of at least one of the following: a second parameter of the wave motion interacted with the suspension, and the first parameter of the wave motion interacted with the suspension at a second wavelength band of the motion, the measurement of the first and second values being synchronized. The arrangement forms at least one comparison being configured to relate to one of the first and one of the second values, and forms a distribution with at least one of first values as a function of one of the comparisons.

A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.

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.