Stiffness and Stiffness Variation in Paper Measured by Laser-Generated and Laser-Recorded Bending Waves

Olofsson, Kenneth; Kyösti, Anders

Research article1994Peer reviewed

Stiffness and Stiffness Variation in Paper Measured by Laser-Generated and Laser-Recorded Bending Waves

Olofsson, Kenneth; Kyösti, Anders

Abstract

Stiffness in paper is measured by holographic interferometry. The displacement field is numerically evaluated using a phase-stepping and phase-unwrapping reconstruction technique. Transient bending waves in the paper sample are generated and recorded by the same pulsed laser. The proposed method can be developed into a commercial on-line measuring device to measure paper stiffness. A number of defects, like variations in thickness, stiffness or density, are identified using this technique.

Keywords

STIFFNESS; PAPER; VARIATIONS; MEASUREMENT; MEASURING INSTRUMENTS; HOLOGRAPHY; INTERFEROMETRY; THICKNESS; DENSITY; LASERS

Published in

Journal of Pulp and Paper Science
1994, volume: 20, number: 11, pages: J328-J333
Publisher: CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION

SLU Authors

Olofsson, Kenneth
- Luleå University of Technology

UKÄ Subject classification

Applied Mechanics

Permanent link to this page (URI)

https://res.slu.se/id/publ/52716