Caliper profile control system for paper machine providing reduced start up times
US5583782A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1994 |
| Grant date | Dec 10, 1996 |
| Priority date | — |
| Expiry date | Nov 10, 2014 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21G1/0046
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A caliper profile control system for a paper machine provides reduced start up times after sheet breaks to bring the caliper profile across the sheet to within the desired limits. The method comprises the steps of scanning at predetermined intervals across the width of the paper sheet to monitor thickness error of the sheet from predetermined limits and change in the thickness error between the intervals, in each of a plurality of zones across the sheet. A control change signal is determined for each of the zones based on the error and the change in error using an exponential function of the magnitude of the error to maximize the change in the error and reduce integral action when the error is large. The control signal is used to reduce the error in each zone and the integral action is increased as the error decreases until the predetermined limits are met.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.