Plain Plywood 1

Plywood is a board-like material consisting of three or more layers of plywood, usually an odd number of layers, which are twisted from a piece of wood into veneer or planed into thin wood and then glued together with adhesive, and the fiber direction of the adjacent layer veneer is glued vertically with each other.

Plywood is one of the common materials used in furniture, which is one of the three largest wood-based panels. A set of veneers is usually glued vertically to each other in the direction of the grain of the adjacent layers, and the inner and outer panels are usually symmetrically arranged on either side of the central layer or core. With the direction of wood grain after the glue-coated veneer staggered into the slab, in the heating or non-heating conditions from pressing. The number of layers is usually odd, and a few have even numbers. The physical and mechanical properties of the Longitudinal and transverse directions have little difference. Commonly used types of plywood are plywood, plywood, and so on. Plywood can improve the utilization ratio of wood and is a main way to save wood.

The general length and width specifications are: 12202440 mm, and the thickness specifications are generally: 3,5,9,12,15,18 mm and so on. The main tree species are: Beech, Camphor, willow, poplar, Eucalyptus, and so on.

In order to improve the anisotropic properties of Natural Wood and make the plywood uniform and stable in shape, two basic principles should be observed in the structure of Plywood: one is symmetry, and the other is that the adjacent veneers are perpendicular to each other. The principle of symmetry is to require veneer on both sides of the plane of plywood symmetry center, no matter wood property, veneer thickness, layer number, fiber direction, moisture content, etc. , should be symmetrical each other. In the same piece of plywood, you can use a single species and thickness of veneer, you can use different species and thickness of veneer, but any two layers on either side of the symmetrical central plane should be of the same thickness. The back board allows for different species of trees.

In order to make the structure of plywood conform to the above two basic principles, the number of its layers should be odd. So plywood is usually made into three layers, five layers, seven layers and so on odd number of layers. The name of each layer of plywood is: the surface veneer is called the surface board, the inner veneer is called the core board; the front panel is called the panel, the back panel is called the backboard; in the core board, the fiber direction parallel to the surface board is called the long core board or the Middle Board. When forming the cavity table slab, the face plate and back plate must be facing outwards.