Plywood is a building multi -layer sheet layer, which is made by gluing a special veneer. The number of veneer sheets varies from 3 or more. In order to increase the strength of the fan -made plywood, the veneer sheets are put so that the fibers of the previous sheet are directed perpendicular to the next. Plywood is used both in construction work and in other areas. In the aviation industry from plywood, they make light “corners”, as such aircraft are cheaper. Used in shipbuilding for the manufacture of various parts. Plywood serves as insulating material in electrical engineering.
The plywood can be classified by many properties. The plywood is divided into longitudinal and transverse. The longitudinal is called plywood, the fibers of which are directed along the long side. If on the contrary, then plywood is called transverse.
Plywood for purpose happens:
Construction. Used in construction or repair.
Furniture. Elite Italian furniture and plywood products are made for household purposes.
Structural. Used for the manufacture of any designs.
The most popular in use is coniferous plywood (or plywood, spruce, fir, etc.). It is inexpensive and not picky in operation. Plywood from birch veneer is superior in all properties of plywood from coniferous or deciduous species of veneer, but much more expensive, therefore it is used only when the use of coniferous plywood is unacceptable.
In large cases, plywood has an odd number of layers. This ensures the symmetry of the location of the veneer layers relative to the central. The use of an odd number of veneer layers is more rational than even, since resistance to deformations increases, the total strength of the plywood sheet.