The key wood treatment technology affecting the quality of mahogany furniture
Guide: Although cracking and deformation of mahogany furniture are not very common, they also occur from time to time. Although cracking and deformation of mahogany furniture are not very common, they also occur from time to time. This is an extremely bad experience for many consumers and manufacturers. Many customers don’t believe that such expensive mahogany furniture will have this kind of problem. Without knowing the reason, most customers first classify the reason as “fake” goods, or the manufacturer’s production process has problems. 1、 Why does mahogany furniture crack? In fact, as long as the furniture is made of real wood, slight cracking is a normal phenomenon, and so is mahogany furniture. There are many reasons for cracking, which should be analyzed according to the specific situation. It can’t be generalized: 1. Mahogany furniture due to wood characteristics is made of precious mahogany, which is the case with wood characteristics. Wood that doesn’t crack doesn’t exist. Generally, mahogany will crack slightly, but it won’t crack, crack through, and a little repair can restore its beauty. 2. Generally, rosewood materials caused by inadequate technology cannot be directly used to make furniture, and their plates must be dried before processing, which is an important step to avoid cracking of rosewood furniture. Now many manufacturers do not carry out strict drying treatment because of equipment, cost and other problems, or do not have enough storage time after drying. 3. Caused by improper maintenance. If the crack is serious, you need to contact the dealer to send a professional mahogany furniture repairman to repair it. 2、 Although there are many reasons for the cracking of mahogany furniture, the wood property of “dry shrinkage and wet expansion” is the “culprit” for the cracking of furniture: when the air is extremely dry, the furniture will lose water and shrink. On the contrary, when the humidity increases, the furniture will absorb water and expand slightly. 1. There are three kinds of water in wood: free water, adsorbed water and bound water. Free water is the water existing in wood cell cavity and cell gap. The change of free water is only related to the apparent density, preservation, flammability and dryness of wood. Adsorbed water is the water adsorbed between fine fibers in the cell wall. The change of adsorbed water is the main factor affecting the strength and swelling and shrinkage of wood. Bound water is the combined water in wood, which does not change at room temperature, so it has no effect on the properties of wood. When there is no free water in the wood and the adsorbed water in the cell wall reaches saturation, the moisture content of the wood at this time is called the fiber saturation point, which is the turning point of the change of wood properties. The value varies with different tree species, temperature and measurement methods, and 30% is usually taken as the average value of water content of each tree species. 2. What is the moisture content of wood? Under normal conditions, wood and its products will have a certain amount of moisture. In China, the percentage of the weight of water contained in wood and the weight of completely dried wood is defined as the moisture content of wood. The moisture content can be calculated based on the weight of all dry wood. The calculated value is called absolute moisture content, which is abbreviated as moisture content (W,%). 3. The importance of wood moisture content why do some wooden furniture, doors, floors and other wood products crack and deform after they are sold? How to reduce the losses of these problems to enterprises? After the wood products are made, the shape and material will not change. At this time, the key factors that determine the internal quality of wood products are mainly wood moisture content and drying stress. Manufacturing enterprises need to correctly grasp the moisture content of wood products. When the wood products reach the equilibrium moisture content when used, the wood at this time is the least prone to cracking and deformation. Dealers selling wood products should also test the moisture content of the products sold to master the quality status of the products sold. Choose manufacturers with good product quality. All manufacturers who pay attention to product quality will test the moisture content of their products. 4. The deformation of wood is caused by the change of adsorbed water in the cell wall of wood. When the moisture content of wood is lower than the fiber saturation point, continue to dry, and the volume shrinks. When the dry wood is hygroscopic, with the increase of adsorbed water, it reaches the moisture content of fiber saturation point. When the moisture content of wood is above the fiber saturation point, and only the free water changes, the volume of wood does not change. Because wood is a heterogeneous material, its swelling and shrinking deformation is different in all directions, among which the chord direction is the largest, the radial direction is the second, and the longitudinal direction (i.e. along the fiber direction) is the smallest. When the wood is dry, the tangential drying shrinkage is about 6% – 12%, the radial drying shrinkage is 3% – 6%, and the longitudinal drying shrinkage is only 0.1% – 0.35%. It is precisely because of the non-uniformity of wood structure that the deformation and warpage of wood may be caused by the expansion and contraction of wood volume. 5. The wood is dry, the drier the better? How dry should it be? When wood is placed in a certain environment for a long enough time, its moisture content will tend to an equilibrium value, which is called the equilibrium moisture content of the environment. When the moisture content of wood is higher than the equilibrium moisture content of the environment, the wood will shrink, otherwise it will hygroscopically expand. For example, the annual average equilibrium water content in Guangzhou is 15.1%, while that in Beijing is 11.4%. Drying to 11% of the wood used in Beijing is appropriate, can be used in Guangzhou will hygroscopic expansion, resulting in deformation. Therefore, wood drying should be appropriate, not the more dry the better. Different regions and different uses have different requirements for wood moisture content. The main reason for the cracking and deformation of mahogany furniture is the imbalance between the moisture content of mahogany and the external environment. The equilibrium moisture content of wood varies with its location. It is about 12% in the north of China, about 18% in the south, and generally 15% in the Yangtze River Basin. 3、 Maintenance and prevention under normal circumstances, mahogany furniture should go through the drying process in the production process, so that the wood property of wet expansion and dry shrinkage deformation can be released before production. To a great extent, this can prevent furniture from cracking and deformation in the process of use, but it is not absolute. We should also pay attention to some maintenance when using. Generally speaking, the precipitation in northern China is less and drier, especially in winter. Mahogany furniture should be placed away from strong light. When using heating and fireplace for heating in winter, do not get close to the furniture to prevent the furniture from fading and cracking. If the climate is particularly dry, you can sprinkle some water on the furniture to prevent warping and cracking. Northern families can install humidifiers to appropriately increase humidity indoors, which is not only good for people’s living, but also helpful for the maintenance of wooden furniture. Of course, don’t let the wooden furniture always be in a damp environment, so as to prevent the furniture from mildew. For example, keeping mahogany furniture close to wet walls for a long time will make the wood hygroscopic and expansive, easy to crack and mildew, so it is necessary to often dehumidify. For a mahogany player, don’t mind whether the wood will crack, swell and deform. Wood is wood, and it’s enough not to crack, so you can be more unscrupulous when you show off mahogany furniture eloquently- This article is from lubanyuan furniture and building materials network.