8 major factors determine the quality of solid wood furniture, now it is not too late!
- Author:Tengyi Furniture
- Release on:2019-07-29
Solid wood furniture refers to pure solid wood furniture, which means that all materials are natural materials that have not been reworked. Furniture without any wood-based panels is used. Because there are no two identical trees, two identical materials, so each A product will have its unique characteristics;
The natural properties of wood, such as mineral lines, color and texture changes, needle joints, resin pouches and other natural imprints, make furniture more natural and aesthetic. At the same time, the quality of wood is also an important factor in determining the quality of solid wood furniture, then what factors will affect the quality of wood??
Temperature is the main factor affecting the drying speed of wood. When the temperature rises, the water pressure in the wood increases, and the viscosity of the liquid free water decreases, which is conducive to promoting the flow and diffusion of moisture in the wood.;The drying capacity of the copper wire drying medium is increased, and the evaporation speed of the surface moisture of the wood is accelerated. However, it is worth noting that if the temperature is too high, it will cause cracking and deformation of wood, reduce mechanical strength, discoloration, etc., and should be properly controlled.
Relative humidity is an important factor affecting the drying speed of wood. In the case of the same temperature and airflow speed, the higher the relative humidity, the greater the partial pressure of water vapor in the medium, and the less the moisture on the surface of the wood evaporates into the medium, the slower the drying speed;
When the relative humidity is low, the surface moisture evaporates quickly, the surface water content decreases, the water content gradient increases, the water diffusion increases, and the drying speed is fast. However, if the relative humidity is too low, cracking and drying defects such as honeycombs may occur or even worsen.
Air circulation speed
Air circulation speed is another factor that affects the drying speed of wood. The high-speed airflow can destroy the saturated vapor boundary layer on the surface of the wood, thereby improving the heat transfer and mass transfer conditions between the medium and the wood, and accelerating the drying speed.
For difficult dry materials or when the moisture content of the wood is low, the moisture movement inside the wood determines the drying speed.;Increasing the evaporation rate of surface moisture by increasing the flow rate of large media has no practical significance, but instead increases the water content gradient and increases the risk of drying defects. Therefore, difficult materials do not require a large media circulation speed.
The above three factors are external factors that can be artificially controlled, properly controlled, and can accelerate the drying speed while ensuring the quality of wood drying.
For example, when dry softwood or soft hardwood sheet is used, the moisture inside the wood is easy to move, and the dry bulb temperature, the medium humidity can be lowered, and the gas flow circulation flow rate can be increased to accelerate the drying speed;
However, when drying mahogany wood or slabs, lower temperatures, higher humidity and lower air circulation rates should be used to avoid drying defects.
Wood species and structural features
The wood of different tree species has different structures, and the size and number of pits and the size of micropores on the pit membrane are very different. Therefore, the difficulty of water movement along the above path is different, that is, the wood species are affected. The main internal cause of drying speed.
Due to the ring-hole hard broad-leaved tree(For example, rosewood)There are many fillers in the conduits and pits, and the diameter of the micropores on the pit membrane is small, so the drying speed is obviously smaller than that of the loose-leaved broad-leaved trees.;In the same tree species, the density increases, the water flow resistance in the large capillary increases, and the water diffusion path in the cell wall prolongs, making it difficult to dry.
The conventional drying process of wood can be approximated as a one-dimensional heat and mass transfer process along the thickness direction of the material. The thickness increases, the heat and mass transfer distance becomes longer, the resistance increases, and the drying speed decreases significantly.
Wood moisture content
Under the fiber saturation point, as the water content decreases, the lateral diffusion coefficient of the sorbed water decreases, while the diffusion coefficient of water vapor in the cell cavity increases, due to the proportion of water vapor diffusing in the cell cavity during drying. It is not large, and the lower the water content, the longer the water diffusion path, so the lower the water content, the more difficult it is to dry.
Wood heart sapwood
There are many inclusions in the heartwood cells of broad-leaved trees, and most of the pits in the heartwood of conifers are occluded, so the heartwood is more difficult to dry than the sapwood.
Wood texture direction
Wood ray is good for water conduction, and the water conduction in the radial direction of the wood is larger than the chord direction.15%-20%Therefore, the string cutting board usually has a faster drying speed than the diameter cutting board.
Although the internal factors cannot be controlled, as long as the characteristics of the wood are used to make good use of the drying equipment and technology, the drying speed can be increased, the unnecessary loss can be reduced, and the drying effect can be improved while maintaining the wood properties.