Patent ID: 11118306

Abstract:
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.