What is plywood?
Plywood is a kind of laminated composite material, which is composed of two or more layers of wood. It is bonded together by heat, pressure and strong resin, and the texture direction is alternating to form a strong composite material.
Four types of glue used in plywood production
Type A bonding uses phenolic resin, which is specially used for marine and external plywood, and will not weaken under wet, hot or cold conditions. Type B adhesive uses melamine reinforced urea-formaldehyde resin, which is suitable for external applications including concrete formwork. Urea-formaldehyde resin is used for C-type and D-type bonds, which are internal bonds and are not recommended for structural applications. Classification and use of five grades
There are five kinds of board quality specified as A, S, B, C and D in descending order. The veneer grade on the front is given first, and then the veneer grade on the back. For example, when only one face is displayed, such as in wall cladding, you can specify the finish quality as AD.
A is high-quality appearance grade veneer for decorative purposes. S is a kind of appearance grade veneer with more natural characteristics. B Suitable for high-quality paint finishing. C has a solid makeup, designed for non-visual applications. D is a non-appearance grade designed for structural applications.
Plywood takes up a large part in the modern wood system. It will be used in ships, houses, engineering walls, and so on. It is possible to completely replace the existing lime cement when it is best matched with the glued wood structural materials.