Plywood as a man-made wood, due to its excellent performance and practicality, is widely used in the field of house construction.
High-quality plywood has certain requirements on the structure and number of layers.
Two principles of plywood
In order to improve the anisotropy of natural wood as much as possible during the processing of the panels, and to make the plywood uniform in wood properties and stable in shape, structurally the plywood needs to comply with two principles: firstly symmetry, and secondly, the fibres of veneers in adjacent layers are perpendicular to each other.
The principle of symmetry means that the veneers on both sides of the plywood centre plane should be symmetrical to each other in terms of wood properties, veneer thickness, number of plies, fibre direction and moisture content. In the same sheet of plywood, veneers of the same species and thickness can be used, or veneers of different species and thickness can be used, but veneers that are symmetrical to each other must be of the same species and thickness.
Natural wood is characterised by a tendency to crack in the direction of the grain, whereas plywood is interlocking vertical layers, so there is no need to worry about possible cracking when nailing or screwing. Due to the balanced structural properties of plywood, the forces on neighbouring veneers cancel each other out, thus reducing warping and deformation of wood due to anisotropy and moisture expansion and contraction.
Is it true that the more layers of plywood, the better?
Plywood is usually made into 3, 5, 7 and other odd layers. So the question is, with a fixed thickness, is it better to have more layers of plywood?
The more layers of plywood means the better it improves the anisotropy of the wood, but more layers also means more glue is used, and a more environmentally friendly glue is needed to meet the requirements.
Fuqing LVL has joined hands with one research institute and three universities to develop a resin adhesive with formaldehyde emission ≤ 0.025mg/m³ after 65 factory tests and 18 technical improvements, promoting product upgrading with green environmental protection.
In addition, the more layers there are, the smaller the thickness of the veneer is, which puts higher requirements on the wood species as well as the production process, so the quality and price of plywood with more layers will be higher accordingly.
Fuqing LVL takes quality as the lifeblood of the enterprise, selecting natural raw materials, intelligent production, and specialised staff to supervise the quality of the whole process. The plywood produced by Fuqing LVL is favoured by customers at home and abroad for its high quality and cost-effective price, and it is the first plywood of its kind to be exported to Japan.
EN
