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

Sammanfattning

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.

Nyckelord

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

Publicerad i

Journal of Pulp and Paper Science
1994, volym: 20, nummer: 11, sidor: J328-J333
Utgivare: CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION

SLU författare

• Olofsson, Kenneth

  • Luleå Tekniska Universitet

UKÄ forskningsämne

Teknisk mekanik

Permanent länk till denna sida (URI)

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