METHOD AND APPARATUS FOR MEASURING AND REMOVING ROTATIONAL VARIABILITY FROM A NIP PRESSURE PROFILE OF A COVERED ROLL OF A NIP PRESS

摘要

Multiple groups of sensors are circumferentially spaced apart at each cross-directional position along a sensing roll of a nip press to measure and cancel or nearly cancel the effects of rotational variability which may be acting on the sensing roll. The strategically-placed sensors are designed to measure the pressure being placed against the web that is being advanced through the nip press. The average of the measurements of multiple sensors spaced circumferential apart provides a good cancellation of any rotational variability that might be found at a cross-directional position on the sensing roll. In this manner, a more true measurement of the nip pressure profile can be obtained and better adjustments made to reduce nip pressure profile variability. In addition, the nip variability profile may be used as a predictor of cover or bearing failures, resonant frequencies and other roll anomalies.

主权项

1. A sensing roll for use in a nip press, comprising:
a substantially cylindrical member having an outer surface and adapted for rotational movement; a roll cover circumferentially overlying the outer surface of the cylindrical member; and a sensing system associated with the roll cover, comprising: a first set of pressure-measuring sensors disposed in a particular configuration along the roll cover, each sensor of the first set being located at a particular cross-directional position on the roll cover; and at least one additional set of pressure-measuring sensors disposed in a particular configuration along the roll cover, each sensor of the second set being located at a particular cross-directional position on the roll cover, wherein each sensor of the first set has a corresponding sensor in the second set which is located at the same cross-directional position but is spaced apart circumferentially in an evenly spaced or unevenly spaced manner.