A web forming device includes: a defibrator having a variable speed rotor, and configured to defibrate defibration feedstock by rotation of the rotor; an accumulator on which defibrated material defibrated by the defibrator accumulates; a thickness detector configured to detect a thickness of the defibrated material accumulated on the accumulator; and a controller configured to control a rotational velocity of the rotor based on a detection result from the thickness detector. The controller applies either or both a first control and a second control, the first control decreasing the rotational velocity of the rotor when variation in the thickness of the deposited defibrated material detected by the thickness detector exceeds a first tolerance, and the second control increasing the rotational velocity of the rotor when a slope of change over time in a thickness of the deposited defibrated material detected by the thickness detector is less than a second tolerance.

A web forming device includes: a defibrator having a variable speed rotor, and configured to defibrate defibration feedstock by rotation of the rotor; an accumulator on which defibrated material defibrated by the defibrator accumulates; a thickness detector configured to detect a thickness of the defibrated material accumulated on the accumulator; and a controller configured to control a rotational velocity of the rotor based on a detection result from the thickness detector. The controller applies either or both a first control and a second control, the first control decreasing the rotational velocity of the rotor when variation in the thickness of the deposited defibrated material detected by the thickness detector exceeds a first tolerance, and the second control increasing the rotational velocity of the rotor when a slope of change over time in a thickness of the deposited defibrated material detected by the thickness detector is less than a second tolerance.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.

A method for producing a structured fibrous web, in particular a tissue web, includes bringing a fibrous suspension into contact with at least one structured forming belt and dewatering by using at least one dewatering element, in particular a suction element. The at least one structured forming belt includes a layer of polymer foam providing a paper-contacting side of the structured forming belt. The structure of the foam layer is at least partially transferred to the fibrous web. A structured forming belt and a machine for producing a fibrous web are also provided.

A method for producing a structured fibrous web, in particular a tissue web, includes bringing a fibrous suspension into contact with at least one structured forming belt and dewatering by using at least one dewatering element, in particular a suction element. The at least one structured forming belt includes a layer of polymer foam providing a paper-contacting side of the structured forming belt. The structure of the foam layer is at least partially transferred to the fibrous web. A structured forming belt and a machine for producing a fibrous web are also provided.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.

A monitoring system comprising: (a) one or more sensors that monitor activity, amplitude, size, scale, duration of activity or a combination thereof of stock on a paper machine and (b) a control system in communication with the one or more sensors and one or more foil sections within the paper machine; wherein the control system measures the activity, amplitude, size, scale, duration of activity or a combination thereof of the stock and correlates the activity, amplitude, size, scale, duration of activity or a combination thereof to formation of fibers within the stock so that an angle, height, or both of the one or more foil sections are adjusted to change the activity, amplitude, size, scale, duration of activity or a combination thereof in the stock.