Plywood is a three or more layers of plate material made of wood cut into veneer or cut into thin wood, and then glued with adhesive, usually with an odd number of veneer, and the fiber direction of the adjacent veneer is glued vertically to each other. The use of plywood also has some principles, follow the principle to better use.
In order to improve the anisotropy of natural wood and make the plywood uniform and stable in shape, the general plywood should follow two basic principles in the structure: one is symmetry; the other is the adjacent layer veneer fiber perpendicular to each other.
The principle of symmetry requires the plywood symmetry on both sides of the central plane, regardless of the veneer, the nature of the wood, veneer thickness, layer number, fiber direction, moisture content, etc., should be symmetrical with each other. In the same plywood, a single tree and thickness can be used, or a veneer of different species and thickness; but the thickness of both sides of the symmetrical center plane should be the same. The face and back is allowed not the same species.
To make the structure of the plywood conform to the above two basic principles at the same time, its number of layers should be odd. So the plywood is usually made of three layers, five layers, seven layers and other odd layers. The name of each layer of plywood is: the panel in the inside layer is called core, the front panel is called face plate, the panel on the back surface the back plate.
When forming the platform slab, the panel and backplane must be tightly facing outward.
