Plywood should conform to the principle of symmetry
In order to improve the anisotropy of natural wood as far as possible and make the plywood uniform and stable in shape, Shandong plywood manufacturers believe that the plywood structure should follow the principle of symmetry and perpendicularity of the adjacent veneer fibers.
First of all, the principle of symmetry requires plywood to be symmetrical in the center and on both sides of the plane, regardless of wood properties, veneer thickness, number of layers, fiber orientation, moisture content and so on. Shandong plywood manufacturers believe that in the same plywood, single species and thickness of veneers can be used, or different species and thickness of veneers can be used; but symmetrical central plane on both sides of any two layers of symmetrical veneer species and thickness should be the same, and the backplane can not be the same species. Therefore, Shandong plywood manufacturers believe that in order to make the plywood structure conform to the above two basic principles, plywood is usually made into three, five, seven odd layers.