Wood veneers and products therefrom having enhanced strength and stiffness

• Main Authors: HUNTER; FRANK R, DIMAKIS; ALKIVIADIS G, PARK; DAVID W
• Format: Patent
• Language: English
• Published: 29.07.1997
• Edition: 6
• Subjects: CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW ORSIMILAR MATERIALS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MANUFACTURE OF SPECIFIC WOODEN ARTICLES; NAILING OR STAPLING MACHINES IN GENERAL; PERFORMING OPERATIONS; PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FORIMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILARMATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITHPERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; TRANSPORTING; WORKING OF WOOD NOT PROVIDED FOR IN SUBCLASSES B27B - B27L; WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL

Wood veneers having enhanced strength and/or stiffness, wood products made therefrom, and methods for manufacturing such veneers and wood products are disclosed. A treated veneer having enhanced strength and stiffness has a population of compacted wood cells extending across at least a portion of the length and width dimensions and into the thickness dimension of the veneer to confer an increased density level, and thus increased strength and/or stiffness levels, to the veneer. Interspersed in the compacted wood cells is a non-saturating loading level of a cured rigid thermoset material which maintains compaction of the compacted cells even after prolonged soaking in water. The preferred loading level is just what is required to maintain compaction of the cells. The preferred thermoset material is polyurea which is formed from a polyisocyanate resin applied to at least one major surface of the veneer followed by hot-pressing the veneer. The strength and/or stiffness increase, compared to untreated veneer, is about 10 to 150 percent. Treated veneers can be made into various multiple-ply wood products such as laminated veneer lumber and plywood, thereby providing a way to convert relatively weak lumber from fast-grown trees into premium-grade construction material.