Weyerhaeuser Company Limited

Weyerhaeueer Company

Tom J Taylor

John E Jones

Mark A Stanish

Stanley L Floyd

Michael James Yancey

Chih-Lin Huang

David C Slaughter

Susan K Kaluzny

Systems and methods are provided for detecting the potential of a wood sample, such as a board, to stay on grade, i.e., resist warp, after it is put into service and/or its moisture has re-equilibrated with the surrounding environment. The systems and methods include various sensor technologies and subjection of obtained data to various models, algorithms, and/or other mathematical formulas.

Methods for determining dimensional stability of wood products utilizing single and multiple sensor groups

A method is described for determining a physical property of a log or similar wood member. A small amount of a liquid or solid is projected against the end of the log with sufficient energy to induce a stress wave. Water is a preferred liquid and an ice pellet is the preferred solid material. A water pulse of about 40 g or less shot from a distance of about 1.2 m with about 9-10,000 kPa pressure will induce a useful shock wave. Similarly an ice pellet weighing 5-10 g shot from the same distance at about 400-500 kPa has given excellent results. The travel time of the stress wave may be measured by an accelerometer in contact with the log. Alternatively, a laser Doppler vibrometer aimed at the log end can record the travel time. The use of the method obviates the need for a mechanical hammer striking the log as well as the requirement for the logs to be even ended at the test location.

Method of determining physical properties of wood

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Seattle, WA, United States of America

Tom J Taylor