Plywood is a three-layer or multi-layer plate-like material made of wood segments cut into veneer or thin wood cut by wood square planing, and then glued with adhesive. Usually, odd layers of veneer are used, and the fiber directions of adjacent layers of veneer are vertically glued to each other.
Plywood is one of the commonly used materials for furniture, one of the three major panels of wood-based panels, and can also be used for aircraft, ships, trains, automobiles, buildings and packaging boxes. A group of veneers is usually formed by gluing each other vertically according to the direction of adjacent layers of wood grain, and usually the surface plate and the inner plate are evenly arranged on both sides of the central layer or the core of the board. A slab made of gelled veneers crisscrossed in the direction of wood grain and pressed under heated or unheated conditions. The number of layers is usually odd, and a few have even numbers. The difference of physical and mechanical properties in vertical and horizontal directions is small.
Commonly used types of plywood are plywood, plywood and so on. Plywood can improve the utilization rate of wood and is a main way to save wood.
Plywood specifications size standard is what
Plywood is generally 2440MM long, 1220MM wide, thickness is divided into 3 cm board, 5 cm board, 9 cm board, 12 cm board, 15 cm board and 18 cm board six specifications (1mm is 1mm). Of course, there are 21 percent and 25 percent, and the thickness can be basically produced according to different requirements.
How to specify the thickness of plywood
The thickness of plywood is 2.7mm, 3.3mm, 4.5mm, 5.5mm, 6mm...... Starting at 6mm and increasing by lmm. Thickness from 4mm below for thin plywood; 3mm, 3.5mm, 4mm thick plywood for common specifications; Plywood of other thicknesses shall be produced by agreement between the supply and demand parties.
Plywood quality requirements include appearance grade, size, physical and mechanical properties of three content.
Appearance grade, size, physical and mechanical properties of the three tests are qualified, judge the product as qualified, otherwise judged as unqualified. The plywood shall have the product quality identification certificate issued by the quality inspection department of the manufacturer when it leaves the factory, indicating the type, specification, grade, bonding strength and moisture content of the plywood.
Appearance grade: Ordinary plywood is divided into four grades according to the visible material defects and processing defects on the plywood after processing: super, first, second and third, of which, one, two and three are the main grades of ordinary plywood.
