A sheet manufacturing apparatus includes a defibrator configured to produce defibrated material, a feedstock supply unit, a monitoring device, and a cleaning device. The feedstock supply unit includes a conveyance device configured to convey feedstock, a storage device configured to accumulate the feedstock conveyed from the conveyance device and supply the feedstock to the defibrator, and a measuring device configured to measure a state of the feedstock accumulated on the storage device. The monitoring device is configured to predict stopping of conveyance of the feedstock by the feedstock supply unit and activate the cleaning device when a conveyance speed of the feedstock by the feedstock supply unit becomes slower than during normal operation. The cleaning device is configured to execute on at least one of the conveyance device and the storage device a cleaning process that preemptively prevents the stopping of conveyance.

A sheet manufacturing apparatus includes a defibrator configured to produce defibrated material, a feedstock supply unit, a monitoring device, and a cleaning device. The feedstock supply unit includes a conveyance device configured to convey feedstock, a storage device configured to accumulate the feedstock conveyed from the conveyance device and supply the feedstock to the defibrator, and a measuring device configured to measure a state of the feedstock accumulated on the storage device. The monitoring device is configured to predict stopping of conveyance of the feedstock by the feedstock supply unit and activate the cleaning device when a conveyance speed of the feedstock by the feedstock supply unit becomes slower than during normal operation. The cleaning device is configured to execute on at least one of the conveyance device and the storage device a cleaning process that preemptively prevents the stopping of conveyance.

The current method relates to an on-line characterization of paper or paper products, such as tissue or other crepe paper products. The method uses an imaging source wherein one or more images are obtained of the sheets surface or topographical area or region, or the image is of an edge of a formed sheet. The one or more images are enhanced and analyzed using various techniques and metrics for characterizing the structure of the formed sheet. The information provides for real time adjustments on the machine.

For operating a drive system or a papermaking machine, motion parameters such as a rotary speed of a motor are determined. From at least one of the motion parameters, a performance value or Key Performance Index is calculated in a motion controller and/or in a non-local computing unit. The performance value is derived from changes in the motion parameters or control parameters over time and displayed to operating personnel on a display. The performance value represents a control performance indicating a control speed responsive to a set motion parameter and thus an operating state of the papermaking machine.

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 monitoring a machine element in a paper finishing machine (10). The machine element mounted for rotation machine elements (16-19) equipped with a sensor assembly (24) measuring force or pressure, and a counter-pair (15, 20, 33, 44) for said machine element. The machine element is made to rotate against the counter-pair, a measurement signal (25) is generated between the machine element and the counter-pair with the sensor assembly, and recording a reference cross-directional profile (21) of force or pressure generated. Condition monitoring (38) of vibration with the reference profile is by comparison of current signals with the reference so as to detect periodic variation (39.1, 39.2) in the cross-directional pressure profile, and producing visual information (37) from the analysis for monitoring. The invention also relates to a corresponding system, a rotating machine element for the method or the system, and a computer program product.

A controller reference trajectory design technique to enable high-performing automatic grade change performed by a model predictive control (MPC). Techniques include: (1) automatic determination of appropriate process output reference trajectory delays to enable optimum coordination of process input movements; (2) providing the entire planning process output reference trajectory ramp at the start of the grade change instead of just incrementally as the grade change progresses, again enabling movement of the process inputs to drive process outputs along the planned future path instead of just towards the current target; and (3) use of the process input forced ramping to allow linear ramping of process inputs with optimal coordination of other process input movements to keep all process outputs following the desired trajectories. The technical benefits are faster and higher performing grade changes. In addition, the use of this technology allows easier setup and maintenance of the automatic grade change package.

A controller reference trajectory design technique to enable high-performing automatic grade change performed by a model predictive control (MPC). Techniques include: (1) automatic determination of appropriate process output reference trajectory delays to enable optimum coordination of process input movements; (2) providing the entire planning process output reference trajectory ramp at the start of the grade change instead of just incrementally as the grade change progresses, again enabling movement of the process inputs to drive process outputs along the planned future path instead of just towards the current target; and (3) use of the process input forced ramping to allow linear ramping of process inputs with optimal coordination of other process input movements to keep all process outputs following the desired trajectories. The technical benefits are faster and higher performing grade changes. In addition, the use of this technology allows easier setup and maintenance of the automatic grade change package.

The thickness of accumulated fiber can be appropriately measured when accumulating and processing fiber. A measuring device includes a distributor 60 that disperses material containing fiber; a mesh belt 72 that accumulates material dispersed by the distributor 60; a roller unit 650 that compresses a second web W2 accumulated on the mesh belt 72; and a measurement device 400 that measures the thickness of the second web W2 after compression by the roller unit 650.

The invention relates to a dust-handling device (1) for collecting and handling dust in a paper-making environment wherein the dust-handling device (1) comprises a source of underpressure (2) and an elongated collector (3) that extends along a longitudinal axis. The elongated collector (3) is connected to the source of underpressure (2) such that underpressure can be generated inside the elongated collector (3) and the elongated collector (3) has an inlet (5) through which dust-laden air can enter the elongated collector (3) and an exit opening (6) through which dust-laden air can be evacuated from the elongated collector. The inlet (5) of the elongated collector (3) is disposed in such a relation to the longitudinal axis of the elongated collector (3) so that upon drawing the dust-laden air into the elongated collector (3), an air vortex is induced with the dust-laden air wherein the induced air vortex flows between the collector inlet (5) and the collector exit opening (6). A source of water (7) is connected to the elongated collector such that water can be introduced into elongated collector (3) so that dust of the dust-laden air can be exposed to and mix with the water introduced into the elongated collector (3). According to the invention, a dust removal device (8, 10) is mounted on the elongated collector and arranged to act against the inlet (5) to remove dust that has clogged the inlet (5). The invention also relates to a method in which dust clogging the inlet (5) is removed.