Patent ID: 6851559
Filing Date: 2005-02-08
Classification: B07C,G01N

Abstract:
1. A method for increasing strength and/or reducing strength variations in multilayer wood, plywood, or sandwich materials having a plurality of wood veneers, one on the other, said method comprising the steps of: measuring dry substance density, as well as longitudinal and lateral distributions of individual wood veneers, with a high-frequency electromagnetic resonance; analyzing homogeneity and/or grain structure of the individual wood veneers from a large number of various points on a wood veneer surface on the basis of optical reflectivity of said surface represented by its darkness; when said optical reflectivity indicates in the individual wood veneer: sorting the wood veneers on the basis of said calculated dry substance densities for at least two different density categories, the dry substance density in a first density category being higher than in a second density category; and laying wood veneers on top of each other for building said multi-layer wood, plywood, or sandwich material, such that veneers graded in the first density category are placed as surface veneers, and veneers graded in the second density category are placed as central veneers.