Pine wood is a valuable material used by humans. Basically, a tree of this kind is used in construction. It is used both for basic work and as an element of external decoration.
Wood
Wood is a material obtained from various species of trees and shrubs. This material is durable, has a fairly long life and relates to renewable resources.
One of the most popular wood materials is pine. It makes strong, beautiful and inexpensive furniture, durable decor items and parquet. Pine is very common in Russia, is the most important in terms of wood supply.
This tree belongs to soft species, that is, it has a low density, which is approximately 520 kg per cubic meter. The density of dry pine is approximately 450-480 kg per cubic meter. This is due to the fact that the moisture contained in the wood gives greater strength to the material.
Wood density
The density of dry pine varies insignificantly, since it depends not only on moisture, but also on the type of tree, place of growth and other important factors. When buying pine need to consider the percentage of its moisture. Manually determine it is not possible without the availability of special equipment, so this procedure is carried out in special laboratories.
Different types of wood have approximately the same composition, so a value of 1.54 is used to calculate the specific gravity. Of course, each type of wood has its own table, it will be located below.
During the purchase of the material, it is worth checking with the manufacturer for its moisture content, since the specific gravity of dry pine will also depend on this parameter. The humidity of pine wood is on average 10-12%. Therefore, with a density of dry pine of about 480 kg per cubic meter, approximately only 50 kg will come from moisture.
Material categories for processing
Conventionally, the material for processing is divided into three categories:
- High specific gravity wood. This type of wood is distinguished by the fact that trees of this species have a density of more than 750 kg per cubic meter: hornbeam, oak, white acacia, etc.
- Trees with medium density. Average values range from 550 to 740 kg per cubic meter: walnut, birch, elm, larch, beech, ash, maple, etc.
- Wood with a low bulk density. In this case, one cubic meter of material will weigh less than 540 kg, and this: ordinary pine, aspen, linden, poplar, ordinary spruce, etc.
The amount of moisture in the lumber can always vary, for example, the boards lying in the sun will be noticeably drier than those that will be covered with an awning.
Moisture determination
For example, you can determine the density of pine wood using a special device called a moisture meter. There are several different methods for determining moisture in a material using this device:
- Dielcometric method.
- Conductometric method.
- Weight method.
The first method of measuring humidity is carried out using a moisture meter, the design of which provides a radio frequency generator. It is he who measures the dielectric constant of the material. The sensors on the device body must be pressed, for example, to a pine board, then the device will begin to send signals into the material about 2-3 centimeters deep and, based on the current decay time, will give data on the percentage moisture in the wood being examined.
The second method involves the partial destruction of the investigated material. It is necessary to stick the sharp needles installed on the device into the object under study, and based on the resistance data between them, a result will be issued.
The third method is the oldest, but it gives very accurate results. To obtain data, you need to take a small amount of the studied material, even a part of the pine board is suitable, and place it in a special chamber for drying. After some time, the weight of the material before drying and after is compared. Thus, the moisture content of the material is calculated.
The third method is simple and reliable, but requires special instruments and scales, which makes it unsuitable for use in some conditions. Also, the price of this device is very high for personal use, so they can most often be found only in special laboratories.