Patent Number: 6,305,224

Title: Method for determining warp potential in wood

Abstract: A method for determining warp potential of wood. One embodiment comprises nondestructively obtaining lengthwise shrinkage rates and grain angles of wood--such as trees, logs, or lumber--then determining warp potential of the wood based on the lengthwise shrinkage rates and grain angles. The method typically comprises measuring plural lengthwise shrinkage rates and plural grain angles to determine warp potential. Where the wood comprises lumber, lengthwise shrinkage rate and grain angle measurements typically are made on at least one major planar surface of the lumber at at least two measuring points separated by a predetermined distance, such as at substantially one-foot intervals along the lumber. Particular embodiments of the present invention determine lengthwise shrinkage rates using electromagnetic energy, acoustic energy, and combinations thereof. Working embodiments of the method use ultrasound energy to determine lengthwise shrinkage rates and grain angles. Another embodiment of the present invention comprises providing a piece of wood having at least one major planar surface, positioning the piece of wood adjacent to a device for imparting energy through the piece of wood to determine at least one lengthwise shrinkage rate and at least one grain angle. Embodiments of the present invention are automated and can be adapted to industrial processes for commercial production of lumber or for forest management practices. Warp potential can be determined using a finite element model (FEM).

Inventors: Stanish; Mark A. (Seattle, WA), Floyd; Stan L. (Enumclaw, WA), Cramer; Steven M. (Lodi, WI)

Assignee: Weyerhaeuser Company

International Classification: G01N 29/44 (20060101); G01N 29/07 (20060101); G01N 29/36 (20060101); G01N 29/04 (20060101); G01N 29/42 (20060101); G01N 33/46 (20060101); G01N 029/18 (); B23Q 015/07 (); B27B 001/00 (); B26D 005/40 ()

Expiration Date: 10/23/2018