Patent ID: 9404895
Filing Date: 2016-08-02
CPC Classification: D21G,G01N,G06N

Claim Text:
1. A method of detecting and addressing chatter from Yankee dryer doctor blades used in the creping process, cleaning, or cut-off operations, the method comprising the steps of: over a period of time, with a sensor constructed and arranged to measure the frequencies and amplitudes of vibrations in a doctor blade as it crepes a paper product, measuring the frequencies and amplitudes of the vibrations indexed by time; collecting the measurements into a time waveform; converting the waveform using a fast Fourier transform, the converted waveform having a frequency spectrum which includes distinct vibration bands; correlating characteristics of the vibration bands with performance properties of the doctor blade to produce correlated vibration bands; defining (i) acceptable performance properties of the doctor blade and (ii) a baseline of acceptable vibration bands based on the correlated vibration bands and the acceptable performance properties of the doctor blade; predicting from the correlated characteristics the degree of deviation from the baseline of acceptable vibration bands associated with doctor blade chatter; predicting from the correlated characteristics the duration of deviation from the baseline of acceptable vibration bands associated with doctor blade chatter; and outputting when a data point on a correlated vibration band indicates excessive doctor blade chatter has occurred based on the predicted degree and duration of deviation from the acceptable vibration bands; and performing one or more corrective actions to address the excessive doctor blade chatter, the one or more corrective actions being from the group consisting of: installing a new doctor blade, reconditioning a surface, replacing a bearing, and lubricating a bearing.