PROCESS FOR THE PRODUCTION OF ENGINEERED PRODUCTS IN WHICH CURING OF THE WOOD IS MONITORED ULTRASONICALLY AND APPARATUS USEFUL THEREFOR

• Main Authors: HUNT, ROBERT N, DUFF, HOWARD S, MCCRACKEN, TIMOTHY S, THIEM, TERRY L
• Format: Patent
• Language: English; French
• Published: 10.07.2007
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUTORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTINGOF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL; MEASURING; NAILING OR STAPLING MACHINES IN GENERAL; PERFORMING OPERATIONS; PHYSICS; TESTING; TRANSPORTING; WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL

Cure of the binder used to produce a lignocellulosic composite material in a press is monitored by (1) inserting a transmitter probe and a receiver probe into the composite-forming mixture at parallel points; (2) passing an ultrasonic signal from the transmitter probe through the composite-forming mixture to the receiver probe; (3) measuring the pulse velocity of the ultrasonic signal; and (4) comparing the measured pulse velocity to that of a standard (i.e., velocity of pulse through a composite article in which the binder is completely cured). When the measured velocity and the velocity of the standard are equal, the composite article is removed from the press. This technique is particularly useful for monitoring the commercial production of composite and engineered wood products.