Plywood - a building material made from layers of wood (veneer) connected to each other.
Characteristic
The main properties of plywood depend on the wood from which it was made. Already from the name it is clear that coniferous plywood is made from coniferous species (spruce, pine). The veneer layers are arranged so that the fibers are perpendicular to each other.
The main characteristics of the material:
- Relatively low cost.
- Light weight material.
- Resists temperature changes.
- Moisture resistant.
- High strength due to the presence of layers.
- Easy to use (can be cut, drilled, etc.).
- Absorbs noise.
- Serves as a layer of thermal insulation.
- The wood is saturated with natural resins, which makes the material resistant to mold and mildew.
- It is rather steady against hostile environment.
- Aesthetically beautiful due to the manifesting structure of wood.
Methods of making plywood
There are three ways:
- Sawing. To obtain veneer, the wood is cut into strips up to 5 mm thick. With this method, raw materials are consumed uneconomically.
- Planing is a more economical method for producing veneers with a thickness of 3.5 mm.
- Plywood logging peeling is a method in which veneers with a thickness of 1.2 to 1.9 mm are obtained.
Which plywood is better: birch or coniferous?
Various types of wood can be used for production : coniferous and deciduous species. The properties of the material obtained depend, of course, on raw materials. Each species has its advantages and disadvantages.
Softwood plywood consists of fewer layers. The material made of larch is more durable, resilient and wear-resistant. For more durable objects, it is better to choose plywood from birch.
Birch veneer has a light shade and poorly pronounced texture. Conifers, on the contrary, are darker and have a beautiful clearly defined pattern.
Coniferous wood is saturated with natural resins. Due to this, materials made from them are less affected by mold and fungi. Coniferous plywood is a relatively cheap building material.
Marking
The quality of the material largely depends on the glue used to connect the veneer layers. Depending on this, coniferous plywood has several markings:
- FBA is the lowest quality brand. It is made using albumincasein glue. This makes it an environmentally friendly material. But such material does not withstand moisture. Apply it only where there is protection against ingress of water.
- FSF is the most popular brand made with phenol-formaldehyde adhesive. It is quite durable and moisture resistant.
- FSF-TV differs from the FSF brand by impregnation with flame retardants. Due to this, coniferous plywood of this species has low combustibility.
- FC is produced using carbamide glue, which makes the material more hygroscopic. Used for the manufacture of furniture, containers, interior structures.
- FB moisture resistant, not exposed to aggressive environments. You can use it even under water. This is achieved by connecting the layers with bakelite glue and impregnating with the same varnish.
- BS is aviation plywood, which got its name due to its use in aviation and shipbuilding. The veneer is glued with bakelite alcohol-soluble glue. Coniferous plywood of this marking is waterproof, durable, flexible and resistant to aggressive environments.
- BV has the same properties as BS. The only difference is that the material of this marking is afraid of moisture (made with water-soluble glue).
All types of plywood differ in surface finish. Depending on this, it can be of three types: unpolished (NS), with one-sided grinding (1) and sanded on both sides (2).
FSF
FSF coniferous plywood is most popular in the construction of civil and industrial facilities. It gains its resistance to water by impregnating layers with poorly soluble formaldehyde resins. After impregnation, the veneer layers are poisoned under the press at high temperature.
GOST permits the release of a certain amount of formaldehyde and phenol compounds. This makes it difficult to use plywood directly indoors.
FSF plywood sheets have standard sizes: 1.22 x 2.44 m, 1.25 x 2.50 m, 1.525 x 3.050 m, 1.525 x 1.525 m. At the same time, the thickness varies between 4-30 mm.
FSF brand plywood has been widely used. The main directions of its use are:
- Temporary structures during construction.
- Sheathing objects.
- Like overlapping under the roof.
- In the construction of wagons, cars and ships for their lining.
- To create garden and country furniture.
- For the construction of formwork (moreover, the material can be used repeatedly).
- As a raw material for the production of other materials.
Plywood is an inexpensive and high-quality building material that has been popular in the market for a long time.