Substrate bending stiffness measurement method and system
US6581456B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 7, 2002 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | Jan 7, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0417
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring substrate bending stiffness and thereby basis weight on a real time basis. Provided is a corrugator having a plurality of parallel ribs, with one or more sheets of the substrate provided below the corrugator wherein a predetermined gap exists between a topmost sheet of the sheets and the corrugator. A vacuum is applied between the corrugator and the topmost sheet, wherein the vacuum is sufficiently large to raise the topmost sheet, thereby deflecting and bending it into a profile corresponding to the arrangement and size of the corrugator ribs and bending stiffness of the substrate. One or more sensors are provided for measuring the deflection of the topmost sheet. The vacuum, an air knife output and/or a fluffer output are then adjusted according to predetermined rules and the measured deflection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.