Hardwood plywood is a three-layer or multi-layer plate-like material that is cut from veneer or cut into veneer by wood and then glued with adhesive. It is usually made of odd-numbered veneer and adjacent The fiber orientation of the plates is perpendicular to each other.
Plywood is one of the common materials of furniture, is a wood-based panel. A group of veneers are usually made in the direction of the adjacent layers in the direction of the adjacent layers. Generally, the panels and the inner plates are arranged symmetrically on either side of the center or the core. With the veneer after the wood by the direction of criss-cross the composition of the slab, in the heating or no heating under the conditions of suppression. The number of layers is generally odd, and few are even. Vertical and horizontal direction of the physical and mechanical properties of small differences. Commonly used plywood, pallets and so on. Plywood can increase wood utilization and is a major way to save wood.
In order to improve the characteristics of natural wood anisotropy, so that the characteristics of plywood uniformity, shape stability, the general plywood in the structure must comply with two basic principles: First, symmetry; Second, the adjacent layer of single plate fiber perpendicular to each other. Symmetry principle is to require veneer symmetry on both sides of the plane of the veneer, regardless of the nature of wood, veneer thickness, layer, fiber direction, moisture content, etc., should be symmetrical. In the same plywood, you can use a single tree and the thickness of the veneer, you can also use different trees and thickness of the veneer; but symmetrical center plane on both sides of any two symmetrical veneer tree and the thickness of the same. The face plate is not allowed to be the same tree species.
To make the structure of the plywood at the same time meet the above two basic principles, its layer should be odd. So plywood are usually made of three, five, seven and other odd number of layers. The name of each layer of the plywood is: the surface of the board is called the table, the inner board is called the core board; the front panel is called the panel, the back of the table is called the back plate; the core, the fiber direction and the table parallel Called a long core plate or a medium plate. When forming a slab plate, the panel and the backplate must face outwardly.