Birch density: calculation of the hardness coefficient
Birch is a tree actively used in the furniture industry. The secret of popularity of such material is not even in the technical characteristics of the breed, but in appearance and absolute ecology.
Application area
Birch in the design of furniture is used due to its technical characteristics:
wood can be easily processed;
When cutting or other mechanical processing does not break off;
in the steamed state it bends well.
Internal finishing work in the house,often do not do without the use of wood. The density of birch makes it possible to use it in carpentry of various types. Taking as a material an array of birch, it is easy to simulate the finish in the house with panels that visually resemble a tree of expensive rock.
Features of wood
Birch has long been dubbed the tree of life. In Russia believed that this is a pure and innocent creature, personifying the soul of a young girl, according to legend, turned into a blond, slender birch tree.
The name of the tree comes from the Indo-European"ber", which means "bright" or "clear". Birch (from the Latin Bétula) is a genus of blond trees belonging to the Birch family. In our region refers to the breed with the highest diversity of species and forms, the density of plantations. That is why the representatives of the forest industry publish different indicators of the value of tree species, depending on the region where the birch is spread. In general, there are about one hundred species of birch trees in the world.
Characteristics of wood
The texture of the tree is layered, with fine curls,often with dark stripes, with a wide color range: from ivory to a gray-red hue. The wood is homogeneous, without inclusions of natural resins. Physico-mechanical characteristics at the highest level. The birch differs high level of strength at mechanical loads - impacts and damages.
The birch is referred to rocks of medium densitywood. The density of birch, as well as other rocks, is determined by a special Brinell scale. According to a specially developed table, the hardness level of wood is marked by a score of 3.5 points.
The norm of natural birch moisture and the density of the material
The density of wood is determined by the special aforementioned scale. Points awarded according to data from the Brinell table, are calculated by the formula, due to which it is possible to calculate the moisture content of the wood and compare it with the norm.
The Brinell density determination schemeis to use a steel tempered ball, whose diameter is only 10 millimeters. It is pushed into the surface of the sample for examination, attaching to it a force of 100 kg. After this, the hole formed is measured. The hardness value is calculated by a special formula, and coefficient, resulting from deductions, and is a measure of density. Than he is taller, the more birch density. It is important to consider that this indicator can vary.
The density of birch is natural humidity (12%) is close to beech and even oak, which makes this wood a more demanded material for furniture production than pine, the distribution of which is much higher, but the density of wood is several times lower.
Humidity is the first factor affecting density. To compare the hardness of wood of different species, the value leads to a single moisture index of 12%. Density and strength characteristics are closely related to each other. Than higher the first indicator, the stronger the tree.
Used in the furniture industry, an iron birch with natural moisture has a hardness of 750 kg / m3 - a tree with a high density of material.
How to determine the density of dry or damp birch?
Raw wood is considered a percentage of moisturewhich exceeds 23%. This indicator is influenced by the time of the tree trimming, as well as the conditions for its further storage. To calculate the density of wet birch, such data will be required: the mass and volume of a tree with a specified humidity. The density of raw birch is calculated by the formula ρW = mW/ VW, where W - Preset moisture of wood.
The density of the material sharply increases under conditions of further moistening.
The moisture content of dry wood is zero. The density of birch is easily calculated from the formula in which the mass is correlated with its volume: ρ0 = m0/ V0
The density index of such a rock will be lower, soas the cell cavity, as well as the intercellular space of the wood is filled with oxygen bubbles. The porous structure is less resistant to mechanical damage.
The tree enters the market in the form of a round timber,lumber, veneer, plywood. The density of the birch, depending on its moisture content, is an important technical characteristic with which you must be acquainted. After all, based on this, the scope of the material is determined.
